AU727636B2 - C-C chemokine receptor 3: CKR-3 or Eos-L2 - Google Patents

Description

S F Ref: 385202D1

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name and Address of Applicant: Leukesit !enc. Millen;um Pa.rmace. Ic.

215 Fir Strt 7~Fe d S ree- ICambridg MaSachusotts 022 LAW4 ;Ja& MaCLzAi.6^e '2iiq UNITED STATES OF AMERICA S. 0 0 *0 C 0**0 Brigham and Women's Hospital Francis Street Boston Massachusetts 02115 UNITED STATES OF AMERICA Children's Medical Center Corporation 300 Longwood Avenue Boston Massachusetts 02115 UNITED STATES OF AMERICA Actual Inventor(s): Address for Service: Invention Title: Craig J. Gerard, Norma P. Gerard, Charles R. Mackay, Paul D. Ponath, Theodore W. Post and Shixin Qin Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia C-C Chemokine Receptor 3: CKR-3 or Eos-L2 The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5845 e- C-C Chemokine Receptor 3: CKR or Eos-L2 Descrint on Backaround Chemokines, also referred to as intecrines are soluble, low molecular weight members of the cytokine family which have chemoattractant function. Chemokines are capable of selectively inducing chemotaxis of the formed Selements of the blood (other than red blood cells), including leukocytes such as monocytes macrophages, 0 eosinophils, basophils, mast cells, and lymphocytes, such as T cells, B cells, and polymorphonuclear leukocytes (neutrophils)). In addition to stimulating chemotaxis, other changes can be selectively induced by chemokines in responsive cells, including changes in cell shape, 15 transient rises in the concentration of intracellular free calcium ([Ca 2 granule exocytosis, integrin upregulation, formation of bioactive lipids 0 leukotrienes) and respiratory burst associated with leukocyte activation. Thus, the chemokines are early 20 triggers of the inflammatory response, causing inflammatory -2- Ineciator release, chemotaxis and extravasation to sites of infection or inflammation.

Xhe chemOlcines characterized to date are related in Primary structure. They share four conserved cysteines, which form disulphide bonds. cDNA cloning and biochemical characterization of several chemolcines has revealed that the proteins have a leader sequence Of 20-25 amino acids, which is cleaved upon secretion to yield a mature protein of approximately 92-99 amino acids. Based on the conserved cysteine motif, the family is divided into two branches# designated as the C-C chemokines (03 chemokines) and the C-X-C chemokines (or chemokines), in which the first two conserved cysteines are adjacent or are separated by an intervening residue, respectively. Baggiolini, M. and C.A.

Dahinden, Xzamunology Today, 15: 127-133 (1994)).

The C-X-C chemokines include a number of chemoattractants which are potent chemoattractants and activators of neutrophils, such as interleukin 8 (IL-8), PF4 and neutrophil-activating peptide 2 (NAP-2). The C-C Chemokines include molecules such as human monocyte cheniotactic proteins 1-3 MCP-2 and MCP-3),

RANTES

(Regulated on Activation, Normal T Expressed and Secreted), and the macrophage inflammatory proteins lar and ifl (MIP-icr and MIP-l1p), which have been characterized as chemoattractants and activators of monocytes or lymphocytes, but do not appear to be chemoattractants for neutrophils. For example, recombinant RANTES is a chemoattractant for monocytes, as well as for memory

T

cells in vitro (Schall, T.J. et al., Nature, 347: 669-673. (1990)). More recently a chemokine called lymphotactin with a single cysteine pair in the molecule has been identified which attracts lymphocytes (Kelner, et al., Science, 266: 1395-1359 (1994)).

The C-C chemokines are of great interest because of their potential role in allergic inflammation. *For -3example, MCP-1 induces exocytosis of human basophils, resulting in release of high levels of inflammatory mediators, such as histamine and leukotriene

C

4 Similarly, there is great interest in the receptors for the C-C chemokines, which trigger these cellular events in response to chemokine binding. A receptor for C-C chemokines has recently been cloned and is reported to bind MIP-la and RANTES. Accordingly, this MIP-la/RANTES receptor was designated C-C chemokine receptor 1 (CKR-1; Neote, K. et al., Cell, 72: 415-425 (1993); Horuk, R. et al., WO 94/11504, published May 26, 1994; Gao, et al., J. Exp. Med., 177: 1421-1427 (1993)). An MCP-1 receptor has also been cloned (Charo, I.F. et al., Proc.

Natl. Acad. Sci. USA, 91: 2752 (1994)). This receptor, designated CKR-2, is reported to bind MCP-1 with high affinity and MCP-3 with lower affinity (Charo, et al., Proc. Natl. Acad. Sci. USA, 91: 2752-2756 (1994)).

CKR-2 has been shown to exist in two isoforms resulting from the use of an alternative splice site in isoform A producing a distinct cytoplasmic tail. Isoform B, which is not spliced in this region, has been shown to be a functional receptor for MCP-1 and MCP-3 in binding and signal transduction assays (Charo, et al., Proc.

Natl. Acad. Sci. USA, 91: 2752-2756 (1994); Myers, et 25 al., J. Biol. Chem., 270: 5786-5792 (1995)). More recently, a new receptor called CKR-4 has been described; CRNA from this receptor was reported to produce a Ca 2 activated chloride current in response to MCP-1, MIP-la, and RANTES when injected in to X. laevis oocytes (Power, et al., J. Biol. Chem., 270: 19495-19500 (1995)).

The MCP-1 receptor (CKR-2) and C-C chemokine receptor 1 are predicted to belong to a superfamily of seven transmembrane spanning G-protein coupled receptors (Gerard and Gerard, Annu. Rev. Immunol., 12: 775-808 -4- (1994); Gerard and Gerard Curr. Opin. Immunol., 6: 140-145 (1994)). This family of G-protein coupled (serpentine) receptors comprises a large group of integral membrane proteins, containing seven transmembrane-spanning regions. The ligands of these receptors include a diverse group of molecules, including small biogenic amine molecules, such as epinephrine and norepinephrine, peptides, such as substance P and neurokinins, and larger proteins, such as chemokines. The receptors are coupled to G proteins, which are heterotrimeric regulatory proteins capable of binding GTP and mediating signal transduction from coupled receptors, for example, by the production of intracellular mediators.

The cloning and sequencing of two IL-8 receptor cDNAs reveals that these C-X-C receptor proteins also share sequence similarity with seven transmembrane-spanning

G

protein-coupled receptor proteins (Murphy P.M. and H.L.

Tiffany, Science, 253: 1280-1283 (1991); Murphy et al., WO 93/06299; Holmes, W.E. et al., Science, 253: 1278-1280 (1991)). Additional receptors for chemotactic proteins such as anaphylatoxin C5a and bacterial formylated tripeptide fMLP have been characterized by cloning and been found to encode receptor proteins which also share sequence similarity to these seven transmembrane-spanning proteins 25 (Gerard, N.P. and C. Gerard, Nature, 349: 614-617 (1991); Boulay, F. et al., Biochemistry, 29: 11123-11133 (1990)).

Although a number of other proteins with significant sequence similarity and similar tissue and leukocyte subpopulation distribution to known chemokine receptors have been identified and cloned, the ligands for these receptors remain undefined. Thus, these proteins are referred to as orphan receptors.

The isolation and characterization of additional genes and the encoded receptors, and the characterization of the corresponding ligands, is essential to an understanding of g the interaction of chemokines with their target cells and the events stimulated by this interaction, including chemotaxis and cellular activation of leukocytes.

Also encompassed by the present invention are methods of identifying ligands of the receptor, as well as inhibitors antagonists) or promoters (agonists) of receptor function. In one embodiment, suitable host cells which have been engineered to express a receptor protein or polypeptide encoded by a nucleic acid introduced into said cells are used in an assay to identify and assess the efficacy of ligands, inhibitors or promoters of receptor function. Such cells are also useful in assessing the function of the expressed receptor protein or polypeptide.

Thus, in a first form of the invention, there is provided a method of identifying an inhibitor of a mammalian C-C chemokine receptor 3 comprising: a) combining a compound to be tested, an isolated protein comprising a naturally occurring mammalian C-C chemokine receptor 3, and a ligand of said receptor under conditions suitable for binding of ligand to said receptor; and b) detecting or measuring the formation of a complex between said receptor and said S 15 ligand, wherein inhibition of complex formation by the compound is indicative that the compound is an inhibitor and wherein said receptor specifically binds a natural ligand of a naturally occurring mammalian C-C chemokine receptor 3.

In a second form of the invention, there is provided a method of identifying an inhibitor of a mammalian C-C chemokine receptor 3 comprising: a) combining a compound to be tested, a ligand or promoter of said receptor, and a host cell expressing a recombinant protein comprising a naturally occurring mammalian C-C chemokine receptor 3 under conditions suitable for detecting a ligand- or promoter-induced response; and I b) determining the ability of the test compound to inhibit said response, 1 25 wherein inhibition of a ligand- or promoter-induced response by the compound is indicative that the compound is an inhibitor and wherein said receptor specifically binds a natural ligand of a naturally occurring mammalian C-C chemokine receptor 3.

In a third form of the invention, there is provided a method of identifying an inhibitor of a human C-C chemokine receptor 3 comprising: 3 0 a) combining a compound to be tested, a ligand of a human C-C chemokine receptor 3, and an isolated protein comprising a naturally occurring human C-C chemokine receptor or (ii) a polypeptide which has at least about 80% amino acid sequence identity with SEQ ID NO:2 or SEQ ID NO:6 under conditions suitable for binding of ligand to said protein or said polypeptide; and R b) detecting or measuring the formation of a complex between said receptor or said polypeptide and said ligand, I :\DayLib\LI BFF]00928spec.doc:gcc I I 6 wherein inhibition of complex formation by the compound is indicative that the compound is an inhibitor and wherein said receptor and said polypeptide specifically bind a natural ligand of a naturally occurring human C-C chemokine receptor 3.

In a fourth form of the invention, there is provided a method of identifying an inhibitor of a human C-C chemokine receptor 3 comprising: a) combining a compound to be tested, a ligand of said receptor, and a host cell expressing a recombinant protein comprising a naturally occurring human C-C chemokine receptor or (ii) a polypeptide which has at least about 80% amino acid sequence identity with SEQ ID NO:2 or SEQ ID NO:6 under conditions suitable for binding of ligand to said receptor or said polypeptide; and b) detecting or measuring the formation of a complex between said protein or said polypeptide and said ligand, wherein inhibition of complex formation by the compound is indicative that the compound is an inhibitor and wherein said receptor and said polypeptide specifically bind a natural ligand of a 5s naturally occurring human C-C chemokine receptor 3.

In a fifth form of the invention, there is provided a method of identifying an inhibitor of a .t human C-C chemokine receptor 3 comprising: 00 a) combining a compound to be tested, a ligand or promoter of said receptor, and a host

S.

0: cell expressing a recombinant protein comprising a naturally occurring human C-C chemokine receptor or (ii) a polypeptide which has at least about 80% amino acid sequence identity with SEQ ID NO:2 or SEQ ID NO:6 under conditions suitable for detecting a ligand- or promoter-induced Goes response; and b) determining the ability of the test compound to inhibit said response, 6 ""6I wherein inhibition of a ligand- or promoter-induced response by the compound is indicative 0 r 2 that the compound is an inhibitor and wherein said receptor and said polypeptide specifically bind a natural ligand of a naturally occurring human C-C chemokine receptor 3.

In a sixth form of the invention, there is provided a method of identifying an inhibitor of a human C-C chemokine receptor 3 comprising: a) combining a compound to be tested, an isolated protein comprising a naturally 3o occurring human C-C chemokine receptor 3, and a ligand of said receptor under conditions suitable for binding of ligand to said receptor; and b) detecting or measuring the formation of a complex between said receptor and said ligand, [I:\DayLib\L BFF]00928spec.doc:gcc e 6a wherein inhibition of complex formation by the compound is indicative that the compound is an inhibitor and wherein said receptor specifically binds a natural ligand of a naturally occurring human C-C chemokine receptor 3.

In a seventh form of the invention, there is provided a method of identifying an inhibitor of a human C-C chemokine receptor 3 comprising: a) combining a compound to be tested, a host cell expressing a recombinant protein comprising a naturally occurring human C-C chemokine receptor 3, and a ligand of said receptor under conditions suitable for binding of ligand to said receptor; and b) detecting or measuring the formation of a complex between said receptor and said 1o ligand, wherein inhibition of complex formation by the compound is indicative that the compound is an inhibitor and wherein said receptor specifically binds a natural ligand of a naturally occurring human C-C chemokine receptor 3.

In an eighth form of the invention, there is provided a method of identifying an inhibitor of a human C-C chemokine receptor 3 comprising: a) combining a compound to be tested with a host cell expressing a recombinant protein comprising a naturally occurring human C-C chemokine receptor 3, and a ligand or promoter of said receptor under conditions suitable for detecting a ligand- or promoter-induced response; and b) determining the ability of the test compound to inhibit said response, o o wherein inhibition of a ligand- or promoter-induced response by the compound is indicative :that the compound is an inhibitor and wherein said receptor specifically binds a natural ligand of a naturally occurring human C-C chemokine receptor 3.

In a ninth form of the invention, there is provided a method of identifying an inhibitor of a mammalian C-C chemokine receptor 3 comprising: 25 a) combining a compound to be tested, an isolated protein comprising a mammalian C-C chemokine receptor 3 encoded by a nucleic acid which hybridizes under high stringency conditions with a nucleic acid selected from the group consisting of SEQ ID NO:1, SEQ ID the complement of SEQ ID NO:1 and the complement of SEQ ID NO:5, and a ligand of said receptor under conditions suitable for binding of ligand to said receptor; and b) detecting or measuring the formation of a complex between said receptor and said ligand, wherein inhibition of complex formation by the compound is indicative that the compound is an inhibitor.

RIn a tenth form of the invention, there is provided a method of identifying an inhibitor of a 3- mammalian C-C chemokine receptor 3 comprising: [I:\DayLib\L BFF]00928spec.doc:gcc 6b a) combining a compound to be tested, a host cell expressing a recombinant protein comprising a mammalian C-C chemokine receptor 3 encoded by a nucleic acid which hybridizes under high stringency conditions with a nucleic acid selected from the group consisting of SEQ ID NO:1, SEQ ID NO:5, the complement of SEQ ID NO:1 and the complement of SEQ ID NO:5, and a ligand of said receptor under conditions suitable for binding of ligand to said receptor; and b) detecting or measuring the formation of a complex between said receptor and said ligand, wherein inhibition of complex formation by the compound is indicative that the compound is an inhibitor.

1o In an eleventh form of the invention, there is provided a method of identifying an inhibitor of a mammalian C-C chemokine receptor 3 comprising: a) combining a compound to be tested, a host cell expressing a recombinant protein comprising a mammalian C-C chemokine receptor 3 encoded by a nucleic acid which hybridizes under high stringency conditions with a nucleic acid selected from the group consisting of SEQ ID NO:1, SEQ ID NO:5, the complement of SEQ ID NO:1 and the complement of SEQ ID NO:5, and a ligand or promotor of said receptor under conditions suitable for detecting a ligand- or promotorinduced response; and b) determining the ability of the test compound to inhibit said response, wherein inhibition of a ligand- or promotor-induced response by the compound is indicative 20 that the compound is an inhibitor.

b According to the present invention, ligands, inhibitors and promoters of receptor function can be identified and further assessed for therapeutic effect. Ligands and promoters can be used to stimulate normal receptor function where needed, while inhibitors of receptor function can be used to reduce or prevent receptor activity. Thus, the present invention provides a new strategy of antiinflammatory therapy, useful in a variety of inflammatory and autoimmune diseases, comprising administering an inhibitor of receptor function to an individual a mammal). In contrast, stimulation of receptor function by administration of a ligand or promoter to an individual provides a new approach to selective stimulation of leukocyte function, which is useful, for example, in the treatment of parasitic infections.

Brief Description of the Drawings Figure 1A-1C illustrates the nucleotide sequence determined from a genomic clone encoding a human CKR-3 protein also referred to as Eos L2 receptor (SEQ ID NO:1), and the predicted amino acid sequence of the protein encoded by the open-reading frame (SEQ ID NO:2).

[I:\DayLib\LIBFF]00928spec.doc:gcc -7- Figure 2A-2B illustrates the nucleotide sequence determined from the cDNAs encoding a human CKR-3 receptor (SEQ ID NO:3), and the predicted amino acid sequence of the protein encoded by the open-reading frame (SEQ ID NO:4).

Figure 3 is an illustration of one type of transendothelial chemotaxis assay. A culture insert is placed into a container, such as a well in a 24-well plate, creating a first and second chamber within the well.

ECV304 endothelial cells are grown in a monolayer on the polycarbonate membrane on the inner side of the insert.

Cells to be assessed for a response to a substance a chemokine) are introduced into the top chamber and the substance is introduced into the bottom chamber.

Chemotaxis can be assessed by detecting cells which migrate through the endothelial layer into the bottom chamber, by removing the insert and detecting or counting cells by a suitable method. For example, cells in the bottom chamber can be collected and assessed by flow cytometry

FACS

analysis, light scattering).

Figure 4 is a histogram illustrating the chemotaxis of human eosinophils in response to various chemokines. Human eosinophils were purified using a standard protocol, and assessed by microscopy for their response to various hemokines in a 24 well transendothelial chemotaxis assay S 25 (cells per high power field (HPF).

Figures 5A-5B are histograms illustrating the response of HL-60 cells (Figure 5A) and butyrate-differentiated HL-60 cells (Figure 5B) to various chemokines. Chemotaxis assays were performed using endothelial coated inserts, and 30 lasted 1.5 hours. Results are representative of different experiments.

Figure 6 is an illustration of a FACS analysis of various clones of L1-2 pre-B cells transfected with Eos L2.

Cells from over 200 clones were stained with M2 anti-FLAG Mab followed by anti-mouse Ig-FITC. (Y-axis, number of -8cells; X-axis, fluorescence). In the negative control (PAUL 001), transfected cells were stained with an irrelevant antibody.

Figure 7 is a histogram illustrating the binding of RANTES and MIP-la to human eosinophils. Purified normal human eosinophils were incubated with 0.1 nM 1 2I-labeled MIP-la or RANTES in the presence or absence of various cold chemokines (MIP-la, RANTES, IL-8, MCP-1, MCP-3) at 250 nM.

Figure 8 is a graph illustrating inhibition of the binding of l2I-labeled RANTES to human eosinophils by various cold chemokines (RANTES, MIP-la, MCP-1 and MCP-3).

Human eosinophils were incubated with 0.1 nM radiolabeled RANTES and the indicated concentrations of cold chemokines.

The data plotted are the means and standard deviations of duplicates for each sample.

Figure 9 is a histogram illustrating the binding of 0.1 nM radiolabeled MIP-la or RANTES to butyric acid differentiated HL-60 cells in the absence or presence of cold chemokines (250 nM).

Figure 10 is a histogram illustrating the binding of 0.1 nM 1 5I-labeled RANTES or 0.1 nM I-labeled MCP-3 to Eos L2 infected SF9 cells (cpm, counts per minute). (From left to right: Hot Rantes only; Hot Rantes 25 Cold Rantes; Hot MCP-3 only; Hot MCP-3 cold MCP-3).

Figures 11A- 1 1 B are graphs illustrating the binding of S MCP-3 to butyrate-differentiated HL-60 cells. In Figure 11A, binding of 0.1 nM radiolabeled MCP-3 was assessed in the presence of various concentrations of cold MCP-3.

Figure 11B is a Scatchard plot calculated from data in Figure 1IA.

Figures 12A-12B are an illustration of the results of a FACS analysis of human eosinophils (Figure 12A) and lymphocytes (Figure 12B) for expression of Eos L2, using -9monoclonal antibody (MAb) LS26-5H12 as first antibody, and FITC-anti-mouse Ig as second antibody. "Neg" indicates a negative control in which non-specific antibody was used as first antibody.

Figures 13A-13D are graphs illustrating CKR-3 expression on leukocytes as determined using MAb LS26-5H12 and flow cytometry. Leukocyte subsets were stained with anti-CKR-3 MAb LS26-5H12 (solid lines) or an IgG, isotype-matched control antibody (MOPC-21) (shaded profile). Figure 13A, eosinophils; Figure 13B, T Cells; Figure 13C, monocytes; Figure 13D, neutrophils. Dead cells were excluded based on propidium iodide staining.

Figures 14A-14C are graphs illustrating cell surface staining of L1.2 cells transiently transfected with a CKR-3 receptor (Figure 14A), mock-transfected L1.2 control cells (Figure 14B), or cell line E5 (a stable L1.2 CKR-3 transfectant) (Figure 14C) with an anti-CKR-3 monoclonal antibody (LS26-5H12, solid line). Background staining with control monoclonal antibody MOPC-21 is also shown (shaded profile).

Figures 15A-15D are graphs illustrating the results of competitive ligand binding of radiolabeled human eotaxin to the E5 cell line (a-stable L1-2 cell line transfected with a CKR-3 receptor; Figure 15A) or to human eosinophils 25 (Figure 15B). Cells were incubated with 0.6 nM 1iI-labeled eotaxin and various concentrations of unlabeled eotaxin RANTES or MCP-3 After 60 minutes at room temperature, cell pellets were washed and counted.

Scatchard plots of unlabeled eotaxin competition were 30 calculated from the data (Figure 15C, E5 cell line; Figure 15D, eosinophils).

Figure 16 is a histogram illustrating the inhibition by various chemokines of human eotaxin binding to the cell line. E5 cells (stable L1-2/CKR-3 transfectants) were incubated with 0.6 nM radiolabeled eotaxin and 250 nM unlabeled chemokines or no competitor as indicated.

Figures 17A-17C are histograms illustrating chemotaxis of L1.2 cells and L1.2 receptor transfectants. 1 x 106 cells of the E5 cell line (stable L1-2/CKR-3 transfectants) (Figure 17A), the parental L1.2 cell line (Figure 17B), or an IL-8 RB L1.2 receptor transfectant line LSLW-2 (Figure 17C) were placed in the top chamber and chemokines placed in the bottom chamber at the concentrations specified.

Migration was allowed for 4 hours and cells migrating to the bottom chamber were counted. All assays were performed in duplicate and the results representative of at least three separate experiments. Chemokines are listed along the x-axis, number of cells migrated along the y-axis, and concentration of chemokine along the z-axis.

Figures 18A-18B are graphs illustrating the chemotactic response of eosinophils from two different individuals. The response resembles that of CKR-3 L1.2 transfectants. Donor to donor variation of chemotactic responses of eosinophils to eotaxin, RANTES, MCP-3, and MIP-la was observed. Eosinophils were purified from blood, and assessed for their chemotactic response to various concentrations of chemokines. Values are from a representative experiment of at least 4 performed, using 25 the same two blood donors.

Figure 19 is a graph illustrating the binding of 12

I-

labeled RANTES to a membranes from a stable cell line (A31-293-20) obtained by transfecting 293 cells with the A31 cDNA clone (square with central dot) as compared with binding to membranes from untransfected 293 cells (filled circles).

Figure 20 is a histogram illustrating the binding of 1I-labeled MCP-3 to a membranes from a stable cell line (A31-293-20) obtained by transfecting 293 cells with the -11- A31 cDNA clone as compared with binding to membranes from untransfected 293 cells. Binding of labeled MCP-3 to membranes from transfected (A31-20) or untransfected (UT293) cells was determined in the absence of cold MCP-3 (0 nM) or in the presence of cold MCP-3 (100 nM).

Figure 21 is a histogram illustrating the specificity of binding, which was assessed by determining the amount of bound 1 'I-labeled MCP-3 which could be displaced by cold MCP-3 from membranes of transfected (A31-20) or untransfected (UT293) cells.

Detailed Description of the Invention As described herein, nucleic acids encoding a novel human receptor, designated Eos L2 or C-C chemokine receptor 3 (CKR-3) have been isolated. Both human genomic and cDNA clones have been characterized. The cDNA clone was isolated from an eosinophil cDNA library constructed from eosinophils obtained from a patient with hypereosinophilic syndrome. Sequence analysis of the clones revealed a gene containing an open reading frame of 1065 nucleotides encoding a predicted protein of 355 amino acids (Figures 1A-1C and 2A-2B; SEQ ID NOS: 2 and which shares amino acid sequence similarity with other C-C chemokine receptors, which are believed to be G protein-coupled receptors and to have a similar structure of seven 25 transmembrane spanning regions.

The predicted proteins encoded by CKR-3 genomic and cDNA clones contain four cysteine residues, one in each of the extracellular domains at positions 24, 106, 183 and 273 (SEQ ID NOS:2 and Cysteines at these positions are 30 conserved in all chemokine receptors, including CKR-1, CKR-2, CKR-4, IL8-RA and IL8-RB. In addition, this receptor contains an amino acid motif, DRYLAIVHA (residues 130-138) (SEQ ID NOS: 2 and which is also highly -12conserved among C-X-C and C-C chemokine receptors and is predicted to be intracellular. There are two consensus sites for protein kinase C phosphorylation (Kishimoto,

A.,

et al., J. Biol. Chem., 260: 12492-12499 (1985); Woodgett, Eur. Biochem., 161: 177-184 (1986)), one in the third intracellular loop at AA position 231, and one in the cytoplasmic tail at AA position 333. In addition, there are eight serine/threonine residues in the cytoplasmic tail, which may serve as phosphorylation sites for G-protein coupled receptor kinases such as those isolated from neutrophils (Haribabu, B. and R. Snyderman, Proc.

Natl. Acad. Sci. USA, 90: 9398 (1993)) or other related family members (Benovic, and Gomez, J. Biol.

Chem., 268: 19521-19527 (1993); Kunapuli, and Benovic, Proc. Natl. Acad. Sci. USA, 90: 5588-5594 (1993)).

Serine/threonine rich cytoplasmic tails are also a common feature of chemokine receptors. Unlike CKR-l, CKR-2, CKR-4, IL-8RA and IL-8RB receptors, CKR-3 does not contain sites for N-linked glycosylation in any extracellular domain. The CKR-3 receptor protein is distinct from C-C chemokine receptor i, also referred to as the MIP-la/RANTES receptor.

The nucleic acid sequences obtained from genomic and cDNA libraries were co-linear, with the following 25 exceptions. Upstream of the initiation codon the two s" sequences diverge (at position 78 of Figure 2A). The genomic clone appears to have an intron which separates the promoter and most of the 5' untranslated region from the coding region. This genomic arrangement is similar to that found in other seven transmembrane-spanning chemoattractant receptors (Gerard, et al., Biochemistry, 32: 1243- 1250 (1993); Murphy, et al., Gene, 133: 285-290 (1993)) including IL-8 RA and RB (Ahuja, et al., J.

Biol. Chem., 269: 26381-89 (1994); Sprenger, et al., J.

35 Biol. Chem., 269: 11065-11072 (1994); Sprenger, et al., gO .g -13- J. Immunol., 153: 2524-2532 (1994)) and CKR-1 (Gao, J.L., et al., J. Exp. Med., 177: 1421-1427 (1993)). Furthermore, examination of the genomic sequence around the point of divergence reveals a canonical splice acceptor sequence.

Initial sequence information revealed two regions in Swhich the cDNA sequence appeared to be shifted in frame, resulting from an insertion of a base followed by the deletion of a base, or the deletion of a base followed by the insertion of a base. These alterations resulted in four contiguous amino acid differences in the predicted proteins at positions 263-266 and 276-279, respectively.

Other differences led to amino acid differences at positions 182, 196, 197, and 315 of the predicted proteins.

The nucleotide sequence presented in SEQ ID NO:5 is a consensus sequence, which includes regions which were sequenced in both clones, and was constructed by simple alignment (base for base) of the initial nucleic acid sequences. SEQ ID NO:6, in which the inital amino acid differences between the cDNA and genomic clones are indicated by Xaa, represents the predicted protein of SEQ ID NO:5. However, further sequence analysis revealed that nucleotide sequences of the open reading frames appear to differ only at a position corresponding to nucleotides 918- 919 of Figure 2B. The genomic clone has a CG at this 25 position, while the cDNA clone has a GC at this position.

Thus, the genomic clone codes for threonine (ACG) at position 276 and the cDNA clone codes for serine (AGC) at position 276. The difference may be due to a sequencing ambiguity, or an error introduced into the cDNA during 30 reverse transcription. Alternatively, the conservative subsitution (serine/threonine) could be due to polymorphism between individuals. Another alternative is that the differences are due to mutation of the receptor gene in the eosinophils of the patient from which RNA for cDNA library construction was obtained.

-14- Monoclonal and polyclonal antibodies specific for a C-C chemokine receptor 3 of human origin were produced using an N-terminal synthetic peptide of the receptor.

FACS (fluorescence activated cell sorting) analysis using one of the monoclonal antibodies revealed significant expression of this receptor on human eosinophils, but not on leukocytes including monocytes, neutrophils, lymphocytes, T cells, T cell blasts (produced by activation with CD3 MAb) (Figures 13A-13D). This pattern of expression was confirmed by Northern analysis with RNA from highly purified leukocyte subsets. However, in some experiments, CKR-3 mRNA or receptor was detected in T lymphocytes; accordingly, it is possible that CKR-3 is expressed on a subset of T lymphocytes (Example Genomic and cDNA clones were also expressed in a variety of systems. Antibody was used to detect expression of receptor from the genomic clone on transfected mammalian cells and baculovirus-transfected insect cells. Stable transfectants of mammalian cells expressing CKR-3 were constructed, and the encoded receptor was shown to bind radiolabeled eotaxin specifically and with high affinity, comparable to the binding affinity observed with eosinophils. Studies with transfected mammalian cells indicated that the receptor also binds RANTES and MCP-3 25 specifically and with high affinity, but not other CC or CXC chemokines tested. Consistent with the binding data, as shown herein, receptor transfectants generated:in a murine B cell lymphoma line migrated in chemotaxis assays in response to eotaxin, RANTES, and MCP-3, but not to any 30 other chemokines tested. When expressed in several heterologous systems, the human receptor did not significantly bind to MIP-la under the conditions used.

Moreover, chemotaxis and ligand binding assays using eosinophils and an eosinophilic-like cell line, indicate that RANTES and MCP-3 bind eosinophils through a receptor, a.

a which is distinct from C-C chemokine receptor 1, the MIP-la/RANTES receptor.

The role of MIP-la as an eosinophil chemoattractant has been controversial. Some investigators detect chemotactic responses (Rot, et al., J. Exp. Med., 176: 1489-1495 (1995)), whereas others do not (Figure 4, Example 1; Ebisawa, et al., J. Immunol., 153: 2153-2160 (1994); and Ponath, et al., J. Clin. Invest., (1996)(in press)). Interestingly, MIP-1a is an eosinophil chemoattractant in the mouse, and this appears to be mediated through the murine CKR-3 homologue, which also binds and signals with murine eotaxin (Post, et al., J. Immunol., 155: 5299-5305 (1995); the teachings of which are incorporated herein by reference in their entirety).

Using the proteins and antibodies of the present invention, additional ligands, as well as additional cell types leukocytes, such as basophils) which express CKR-3 receptor, can be identified. The ability of other chemokines to bind mammalian CKR-3 receptors can be assessed according to the present invention.

The cloning and characterization of clones encoding a novel receptor, and the isolation and characterization of the novel CKR-3 receptor which demonstrably binds and mediates chemotaxis in response to chemokines such as 25 eotaxin, RANTES and MCP-3, suggests that this receptor is a member of a family of seven transmembrane spanning G protein-coupled receptors which are involved in selective leukocyte chemotaxis and activation in response to chemokines. The CKR-3 receptor and its mammalian homologs are distinct from the MIP-la/RANTES receptor and the MCP-1 receptor are receptors other than C-C chemokine receptor 1 (CKR-1) and MCP-1 receptor (CKR-2) and their homologs).

Because of the role of chemokine receptors in the 35 selective induction of leukocyte chemotaxis and leukocyte o -16activation in response to chemoattractants, chemokine receptors play a fundamental role in leukocyte migration and particularly in migration associated with inflammation.

Chemokines, produced at sites of inflammation and infection, specifically recruit selected leukocyte subtypes from the circulation to the site of inflammation in the tissues. Subsequent to chemokine binding to a leukocyte chemokine receptor, integrin activation occurs, and leukocytes adhere firmly to the endothelial cell wall via leukocyte integrins and endothelial cell adhesion molecules. The leukocytes become flat in shape, and migrate through the endothelium towards sites of inflammation in the tissues. The specificity of a leukocyte for a tissue or inflammatory site is, in many cases, determined at the level of the chemokine-receptor interaction, rather than at the level of the adhesion interaction between integrin and cellular adhesion molecules.

RANTES and MCP-3 are among the most potent chemotactic cytokines for eosinophils and basophils. In addition, RANTES is reported to be a chemoattractant for memory

T

cells, a subpopulation of T lymphocytes. As shown herein, RANTES and MCP-3 can induce chemotaxis of eosinophils and eosinophil-like cells. CKR-3 receptor proteins described 25 herein also bind RANTES and MCP-3 with high affinity.

As is further shown herein, CKR-3 binds eotaxin specifically and with high affinity (comparable to the binding affinity observed with eosinophils), and the CKR-3 receptor is highly restricted in its expression. Although a number of chemoattractants have been identified for eosinophils, such as RANTES and MCP-3 (Baggiolini, M. and Dahinden, Immunol. Today, 15: 127-33 (1994); Dahinden, et al., J. Exp. Med., 179: 751-756 (1994); Kameyoshi, Y, et al., J. Exp. Med., 176: 587-592 (1992); Rot, et al., J. Exp. Med., 176: 1489-1495 (1995)), as -17well as PAF, C5a, and IL-16 (Wardlaw, et al., 470 Clin. Invest., 78: 1701-1706 (1986); Gerard, et al., J. Biol. Chem., 264: 1760-1765 (1989); Rand, et al., J. Exp. Med., 173: 1521-1528 (1991)), these chemoattracants also induce the migration of other leukocyte cell types.

In contrast, the chemok ine eotaxin, a potent eosinophil chemoattractant originally identified in guinea pigs and subsequently in mouse and human, is selectively chemotactic for eosinophils (Jose, et al., Biochem. Blophys. Res.

Commzzn., 205: 788-794 (1994); Jose, et al., Exp.

Med., 179: 881-887 (1994); Rothenburg, M.E. et al., Proc.

Natl. Acad. Sci. 92: 8960-8964 (1995); Ponath, et al., Clin. Invest., (1 9 9 6) (in press)). In addition, eotaxin binds to and signals through CKR-3 with a high degree of fidelity, in contrast to chemokines such as MCP-3, which binds cKR-1 and CKR-2 (Ben-Baruch, et al., J. Biol. Chem., 270: 22123-22128 (1995)) in addition to CKR-3, or MIP-1a, which binds CKR-1 and CKR-4 (Neote; X., et al., Cell, 72: 415-425 (1993); Power,..C.A., et al.,

LT.

Biol. Chem., 270: 19495-19500 (1995)). The restricted expression of CKR-3 on eosinophils, and the fidelity of eotaxin binding to CKR-3, provides a potential mechanism for the selective recruitment and migration of eosinophils within tissues. In this regard, the production of eotaxin within a tissue can lead to selective eosinophil recruitment; eotaxin injection into the skin of rhesus monkeys leads to selective eosinophil migration. in addition, eotaxin was shown to recruit eosinophils in vivo at a 10-fold lower dose than RANTES, similar to the in vitro chemotaxis of CKR-3 transfectants (Ponath, et al., J. Cdin. Invest., (1 9 96) (in press)).

Modulation of mammalian CKR-3 receptor function according to the present. invention, through the inhibition or promotion of receptor function, such as binding, signalling or stimulation of a cellular response, provides -18an effective and selective way of inhibiting or promoting leukocyte-mediated inflammatory action, particularly that of eosinophils and/or T cells. Ligands, inhibitors and promoters of CKR-3 receptor function, such as those identified as described herein, can be used to modulate leukocyte function for therapeutic purposes.

Eosinophils do not express the MIP-la receptor, and do not express significant amounts of MCP-1 receptor. In addition, as noted above, eotaxin and RANTES are some of the most potent chemoattractants for eosinophils, and eotaxin and RANTES bind specifically and with high affinity to the CKR-3 receptor. As a major eosinophil and lymphocyte chemokine receptor, the CKR-3 receptor is an important target for interfering with or promoting eosinophil and/or T lymphocyte function. Compounds which inhibit or promote CKR-3 receptor function, such as ligands, inhibitors and promoters identified according to the present method, are particularly useful for modulating eosinophil and/or T cell function for therapeutic purposes.

Nucleic Acids. Constructs and Vectors The present invention relates to isolated and/or recombinant (including, essentially pure) nucleic acids having sequences which encode a mammalian human) receptor protein designated Eos L2 or C-C Chemokine Receptor 3 (CKR-3) or a portion of said receptor. In one embodiment, the nucleic acid or portion thereof encodes a protein or polypeptide having at least one function characteristic of a mammalian C-C chemokine receptor a mammalian CKR-3 receptor), such as a binding activity 30 ligand, inhibitor and/or promoter binding), a signalling activity activation of a mammalian

G

protein, induction of rapid and transient increase in the concentration of cytosolic free calcium and/or -19stimulation of a cellular response stimulation of chemotaxis, exocytosis or inflammatory mediator release by leukocytes, integrin activation). The present invention also relates more specifically to isolated and/or recombinant nucleic acids or a portion thereof comprising sequences which encode a mammalian CKR-3 receptor or a portion thereof.

The invention further relates to isolated and/or recombinant nucleic acids that are characterized by (1) their ability to hybridize to: a nucleic acid having the sequence SEQ ID NO:1, SEQ ID NO:3 or SEQ ID NO:5, a the complement of any one of SEQ ID NOS:1, 3 or 5, a portion of the foregoing comprising the coding region (nucleotides 181-1245 of SEQ ID NO:1, nucleotides 92-1156 of SEQ ID NO:3, or nucleotides 15-1079 of SEQ ID NO:5), or the RNA counterpart of any one of the foregoing, wherein

U

is substituted for T; or by their ability to encode a polypeptide having the amino acid sequence SEQ ID NO:2, SEQ ID NO:4 or SEQ ID NO:6 or a functional equivalents thereof a polypeptide having ligand binding activity for one or more natural or physiological ligand(s) of the receptor and/or stimulatory function responsive to ligand binding, such that it can stimulate a cellular response stimulation of chemotaxis, exocytosis or inflammatory mediator release by leukocytes); or by both characteristics.

In one embodiment, the percent amino acid sequence identity between SEQ ID NOS:2, 4 or 6 and functional equivalents thereof is at least about 70% (2 In a preferred embodiment, functional equivalents of SEQ ID NOS:2, 4 or 6 share at least about 80% sequence identity w. ith SEQ ID NOS:2, 4 or 6, respectively. More preferably, the percent amino acid sequence identity between SEQ ID NOS:2, 4 or 6 and functional equivalents thereof is at least about 90%, and still more preferably, at least about Isolated and/or recombinant nucleic acids meeting these criteria comprise nucleic acids having sequences identical to sequences of naturally occurring mammalian CKR-3 receptors and portions thereof, or variants of the naturally occurring sequences. Such variants include mutants differing by the addition, deletion or substitution of one or more residues, modified nucleic acids in which one or more residues is modified DNA or RNA analogs), and mutants comprising one or more modified residues.

Such nucleic acids can be detected and isolated by hybridization under high stringency conditions or moderate stringency conditions, for example. "High stringency conditions" and "moderate stringency conditions" for nucleic acid hybridizations are explained on pages 2.10.1- 2.10.16 (see particularly 2.10.8-11) and pages 6.3.1-6 in Current Protocols in Molecular Biology (Ausubel, F.M. et al., eds., Vol. 1, Suppl. 26, 1991), the teachings of which are incorporated herein by reference (see also Example 2).

Factors such as probe length, base composition, percent mismatch between the hybridizing sequences, temperature and ionic strength influence the stability of nucleic acid hybrids. Thus, high or moderate stringency conditions can be determined empirically, depending in part upon the characteristics of the known DNA to which other unknown nucleic acids are being compared for homology.

Isolated and/or recombinant nucleic acids that are characterized by their ability to hybridize to a nucleic acid having the sequence SEQ ID NOS: 1, 3 or 5 or the 30 complements of any one of SEQ ID NOS: 1, 3 or 5 under high or moderate stringency conditions) may further encode a protein or polypeptide having at least one function characteristic of a mammalian C-C chemokine receptor a mammalian CKR-3 receptor), such as a binding activity ligand, inhibitor and/or promoter binding), a oo -21signalling activity activation of a mammalian

G

protein, induction of rapid and transient increase in the concentration of cytosolic free calcium [Ca 2 and/or stimulation of a cellular response stimulation of chemotaxis, exocytosis or inflammatory mediator release by leukocytes, integrin activation).

The signalling function of a protein or polypeptide encoded by hybridizing nucleic acid can be detected by enzymatic assays for G protein activity responsive to receptor binding exchange of GTP for GDP on the G protein a subunit, using membrane fractions). G protein coupling can be further assessed, for example, using assays in which stimulation by G protein is blocked by treatment or pre-treatment of cells or a suitable cellular fraction membranes) with specific inhibitors of G proteins, such as Bordetella pertussis toxin (Bischoff, S.C. et al., Eur. J. Immunol. 23: 761-767 (1993); Sozzani, S. et al., J.

Immunol. 147: 2215-2221 (1991)).

The stimulatory function of a protein or polypeptide encoded by hybridizing nucleic acid can be detected by standard assays for chemotaxis or mediator release, using cells expressing the protein or polypeptide assays which monitor chemotaxis, exocytosis of enzymes such as eosinophil peroxidase, 0-glucuronidase) or mediator release in response to a ligand a chemokine such as eotaxin, RANTES or MCP-3) or a promoter.

The binding function of a protein or polypeptide encoded by hybridizing nucleic acid can be detected in binding or binding inhibition assays using membrane 30 fractions containing receptor or cells expressing receptor, for instance (see Example 9; Van Riper et al., J.

Exp. Med., 177: 851-856 (1993); Sledziewski et al., U.S.

Patent No. 5,284,746 (Feb. 8, 1994)). Thus, the ability of the encoded protein or polypeptide to bind a ligand, such -22as eotaxin, RANTES or MCP-3, an inhibitor and/or promoter can be assessed. Functions characteristic of a mammalian CKR-3 receptor may also be assessed by other suitable methods (see below).

These methods, alone or in combination with other suitable methods can also be used in procedures for the identification and/or isolation of nucleic acids which encode a polypeptide having the amino acid sequence SEQ ID NO: 2, 4, 6 or functional equivalents thereof, and having an activity detected by the assay. Portions of the isolated nucleic acids which encode polypeptide portions of SEQ ID NO: 2, 4 or 6 having a certain function can be also identified and isolated in this manner.

Nucleic acids of the present invention can be used in the production of proteins or polypeptides. For example, a nucleic acid containing all or part of the coding sequence for a mammalian CKR-3 receptor, or DNA which hybridizes to the sequence SEQ ID NO: 1, 3 or 5, or the complement of any one of SEQ ID NO: i, 3 or 5, can be incorporated into various constructs and vectors created for further manipulation of sequences or for production of the encoded polypeptide in suitable host cells.

Nucleic acids referred to herein as "isolated" are nucleic acids separated away from the nucleic acids of the genomic DNA or cellular RNA of their source of origin as it exists in cells or in a mixture of nucleic acids such as a library), and may have undergone further processing. "Isolated" nucleic acids include nucleic acids obtained by methods described herein, similar methods or 30 other suitable methods, including essentially pure nucleic acids, nucleic acids produced by chemical synthesis, by combinations of.biological and chemical methods, and Srecombinant nucleic acids which are isolated. Nucleic acids referred to herein as "recombinant" are nucleic acids which have been produced by recombinant DNA methodology, -23including those nucleic acids that are generated by procedures which rely upon a method of artificial recombination, such as the polymerase chain reaction

(PCR)

and/or cloning into a vector using restriction enzymes.

"Recombinant" nucleic acids are also those that result from recombination events that occur through the natural mechanisms of cells, but are selected for after the introduction to the cells of nucleic acids designed to allow and make probable a desired recombination event.

Antisense Constructs In another embodiment, the nucleic acid is an antisense nucleic acid, which is complementary, in whole or in part, to a target molecule comprising a sense strand, and can hybridize with the target molecule. The target can be DNA, or its RNA counterpart wherein T residues of the DNA are U residues in the RNA counterpart). When introduced into a cell using methods known in the art or other suitable methods, antisense nucleic acid can inhibit the expression of the gene encoded by the sense strand.

Antisense nucleic acids can be produced by standard techniques.

In one embodiment, the antisense nucleic acid is wholly or partially complementary to and can hybridize with a target nucleic acid, wherein the target nucleic acid can hybridize to a nucleic acid having the sequence of the complement of SEQ ID NO:1, 3 or 5. For example, antisense nucleic acid can be complementary to a target nucleic acid having the sequence of SEQ ID NO: 5 or a portion thereof sufficient to allow hybridization. In another embodiment, the antisense nucleic acid is wholly or partially complementary to and can hybridize with a target nucleic Sacid which encodes a mammalian CKR-3 receptor human Eos L2 receptor).

-24- Antisense nucleic acids are useful for a variety of purposes, including research and therapeutic applications.

For example, a construct comprising an antisense nucleic acid can be introduced into a suitable cell to inhibit receptor expression. Such a cell provides a valuable control cell, for instance in assessing the specificity of receptor-ligand interaction with the parent cell or other related cell types. In another aspect, such a construct is introduced into some or all of the cells of a mammal. The antisense nucleic acid inhibits receptor expression, and inflammatory processes mediated by CKR-3 receptors in the cells containing the construct can be inhibited. Thus, an inflammatory disease or condition can be treated using an antisense nucleic acid of the present invention. Suitable laboratory animals comprising an antisense construct can also provide useful models for deficiencies of leukocyte function, and of eosinophil deficiency in particular, and provide further information regarding CKR-3 receptor function. Such animals can provide valuable models of infectious disease, useful for elucidating the role of leukocytes, such as eosinophils and/or T lymphocytes, in host defenses.

Mammalian Nucleic Acids Because advances in the understanding and treatment of human inflammatory and autoimmune diseases and of parasitic infections would be of tremendous benefit, human CKR-3 was the species selected for most of the experimental work described herein. However, the approaches described to isolate and manipulate the genomic and cDNAs of human CKR-3 30 (Eos L2), to construct vectors and host strains, and to produce and use the receptor or fragments thereof, can be applied to other mammalian species, including, but not limited to primate a primate other than a human, such as a monkey cynomolgus monkey)), bovine cows), ovine sheep), equine horses), canine dog), feline domestic cat) and rodent guinea pig, murine species such as rat, mouse) species.

The human CKR-3 cDNA or genomic clones described here, or sufficient portions thereof, whether isolated and/or recombinant or synthetic, including fragments within the coding sequence produced by PCR, can be used as probes to detect and/or recover homologous CKR-3 genes (homologs) or other related receptor genes novel C-C chemokine receptor genes) from other mammalian species by hybridization, PCR or other suitable techniques). This can be achieved using the procedures described herein or other suitable methods.

Proteins and Peptides The invention also relates to proteins or polypeptides encoded by nucleic acids of the present invention. The proteins and polypeptides of the present invention can be isolated and/or recombinant. Proteins or polypeptides referred to herein as "isolated" are proteins or polypeptides purified to a state beyond that in which they exist in mammalian cells. "Isolated" proteins or polypeptides include proteins or polypeptides obtained by methods described herein, similar methods or other suitable methods, including essentially pure proteins or polypeptides, proteins or polypeptides produced by chemical synthesis, or by combinations of biological and chemical methods, and recombinant proteins or polypeptides which are isolated. Proteins or polypeptides referred to herein as "recombinant" are proteins or polypeptides produced by the 30 expression of recombinant nucleic acids.

In a preferred embodiment, the protein or polypeptide has at least one function characteristic of a mammalian CKR-3 receptor, such as a binding activity ligand, inhibitor and/or promoter binding), a signalling activity o -26activation of a mammalian G protein, induction of rapid and transient increase in the concentration of cytosolic free calcium and/or stimulation of a cellular response stimulation of chemotaxis, exocytosis or inflammatory mediator release by leukocytes, integrin activation). As such, these proteins are referred to as CKR-3 proteins of mammalian origin or mammalian chemokine receptor 3 proteins, and include, for example, naturally occurring mammalian CKR-3 receptors, variants of those proteins and/or portions thereof. Such variants include polymorphic variants and natural or artificial mutants, differing by the addition, deletion or substitution of one or more amino acid residues, or modified polypeptides in which one or more residues is modified, and mutants comprising one or more modified residues. An example would be a mammalian CKR-3 receptor protein which binds eotaxin.

In a particularly preferred embodiment, like naturally occurring mammalian CKR-3 receptor proteins or polypeptides, the mammalian CKR-3 receptors of the present invention have ligand binding function for one or more natural or physiological ligand(s) and/or stimulatory function responsive to ligand binding, such that they can stimulate a cellular response stimulation of chemotaxis, exocytosis or inflammatory mediator release by leukocytes). For example, in the case of a human chemokine receptor 3 protein, an isolated human CKR-3 protein will :i bind the one or more natural or physiological ligand(s).

As shown herein, an isolated human CKR-3 protein binds 30 eotaxin and RANTES specifically and with high affinity, and specifically binds MCP-3. In one embodiment, a human CKR-3 receptor protein or polypeptide also triggers chemotaxis, exocytosis or inflammatory mediator release by leukocytes in response to ligand binding.

-27- The invention further relates to fusion proteins, comprising a mammalian CKR-3 receptor protein or polypeptide (as described above) as a first moiety, linked to a second moiety not occurring in the mammalian CKR-3 receptor as found in nature. Thus, the second moiety can be an amino acid or polypeptide. The first moiety can be in an N-terminal location, C-terminal location or internal to the fusion protein. In one embodiment, the fusion protein comprises a human CKR-3 receptor as the first moiety, and a second moiety comprising a linker sequence and affinity ligand an enzyme, an antigen, epitope tag).

Fusion proteins can be produced by a variety of methods. For example, some embodiments can be produced by the insertion of a CKR-3 gene or portion thereof into a suitable expression vector, such as BluescripteII SK (Stratagene), pGEX-4T-2 (Pharmacia) and pET-15b (Novagen).

The resulting construct is then introduced into a suitable host cell for expression. Upon expression, fusion protein can be isolated or purified from a cell lysate by means of a suitable affinity matrix (see Current Protocols in Molecular Biology (Ausubel, F.M. et al., eds., Vol. 2, Suppl. 26, pp. 16.4.1-16.7.8 (1991)). In addition, affinity labels provide a means of detecting CKR-3 receptor proteins or polypeptides present in a fusion protein. For example, the cell surface expression or presence in a .:particular cell fraction of a fusion protein comprising an antigen or epitope affinity label can be detected by means of an appropriate antibody (see, Example 3).

S 30 The invention also relates to isolated and/or recombinant portions of a CKR-3 receptor of mammalian origin, such as a fragment of a human CKR-3 receptor. As is described in more detail below, portions of a mammalian CKR-3 receptor can be produced synthetic peptides) 35 and used to produce antibodies. In one embodiment, an e* .o 55 -28isolated and/or recombinant portion a peptide) of a selected mammalian CKR-3 receptor has at least one immunological property. As used herein, with reference to a portion of a receptor, an immunological property includes immunoreactivity (bound by antibodies raised against a mammalian CKR-3 receptor protein of the present invention including a portion thereof), immunogenicity (induces an antibody response against itself when used in a suitable immunization protocol), and/or cross-reactivity (induces antibodies reactive with a selected mammalian receptor).

Furthermore, portions of a CKR-3 receptor having at least one function characteristic of mammalian CKR-3 receptors, such as binding activity, signalling activity, or stimulatory function (stimulation of a cellular response), can also be produced. Extensive studies on the structure and function of mammalian G protein-coupled receptors provide the basis for being able to divide mammalian CKR-3 receptors into functional domains (see Lefkowitz et al., J. Biol. Chem., 263: 4993-4996 (2988); Panayotou and Waterfield, Curr. Opinion Cell Biol., 1: 167-176 (1989)).

Furthermore, portions of the receptor can be produced which have full or partial function on their own, or which when joined with another portion of a second receptor (though fully, partially, or nonfunctional alone), constitute a functional protein having at least one function characteristic of a mammalian CKR-3 receptor ligand-, inhibitor- or promoter-binding function).. (See, Sledziewski et al., U.S. Patent No. 5,284,746 regarding the construction and use of hybrid G protein-coupled receptors useful in detecting the presence of ligand in a test sample).

.e '-29- Method of Producing Recombinant Mammalian CKR-3 Recentors Another aspect of the invention relates to a method of producing a mammalian CKR-3 receptor or a portion thereof.

Constructs suitable for the expression of a mammalian CKR-3 receptor or a portion thereof are also provided. The constructs can be introduced into a suitable host cell.

Cells expressing a recombinant mammalian CKR-3 receptor or a portion thereof can be isolated and maintained in culture. Such cells are useful for a variety of purposes such as the production of protein for characterization, isolation and/or purification, and in binding assays for the detection of ligands, or inhibitors or promoters of ligand binding. Suitable host cells can be procaryotic, including bacterial cells such as E. coli, B. subtilis and or other suitable bacteria, or eucaryotic, such as fungal or yeast cells Pichia pastoris, Aspergillus species, Saccharomyces cerevisiae, Schizosaccharomyces pombe, Neurospora crassa), or other lower eucaryotic cells, and cells of higher eucaryotes such as those from insects Sf9 insect cells) or mammals 293 cells, Chinese hamster ovary cells (See, Ausubel, F.M. et al., eds. Current Protocols in Molecular Biology, Greene Publishing Associates and John Wiley Sons Inc., (1993)).

Host cells which produce a recombinant mammalian CKR-3 receptor protein, portion thereof, or fusion protein can be produced as follows. A nucleic acid encoding all or part of the coding sequence for a mammalian CKR-3 receptor or fusion protein can be inserted into a nucleic acid vector, 30 a DNA vector, such as a plasmid, virus or other suitable replicon for expression. A variety of vectors are available, including vectors which are maintained in single copy or multiple copy, or which become integrated into the host cell chromosome.

The transcriptional and/or translational signals of a selected CKR-3 receptor can be used to direct expression.

Alternatively, suitable expression vectors are available.

Suitable vectors for expression of a nucleic acid encoding all or part of the coding sequence for a mammalian CKR-3 receptor or fusion protein can contain a number of additional components, including, but not limited to one or more of the following: an origin of replication; a selectable marker gene; one or more expression control elements, such as a transcriptional control element a promoter, an enhancer, terminator), and/or one or more translation signals; a signal sequence or leader sequence (for membrane targeting encoded by the vector or receptor).

A promoter is provided for expression in a suitable host cell. Promoters can be constitutive or inducible. In the vectors, the promoter is operably linked to a nucleic acid encoding the receptor protein, portion thereof or fusion protein, and is capable of directing expression of the encoded polypeptide. A variety of suitable promoters for procaryotic lac, tac, T3, T7 promoters for E.

coli) and eukaryotic yeast alcohol dehydrogenase (ADH1), SV40, CMV) hosts are available.

In addition, the expression vectors typically comprise a selectable marker for selection of host cells carrying the vector and an origin or replication, in the case of replicable expression vector. Genes encoding products which confer antibiotic or drug resistance are common selectable markers and may be used in prokaryotic

B-

lactamase gene (ampicillin resistance), Tet gene for 30 tetracycline resistance) and eukaryotic cells neomycin (G418 or geneticin), gpt (mycophenolic acid), ampicillin, or hygromycin resistance genes). Dihydrofolate reductase marker genes permit selection with methotrexate in a variety of hosts. Genes encoding the gene product of 35 auxotrophic markers of the host LEU2, URA3, HIS3) -31are often used as selectable markers in yeast. Use of viral baculovirus) or phage vectors, and vectors which are capable of integrating into the genome of the host cell, such as retroviral vectors, are also contemplated. The present invention also relates to cells carrying these expression vectors.

When the nucleic acid encoding the receptor protein or polypeptide is inserted into the vector, operably linked to one br more of these components, and the resulting construct is introduced into host cells maintained under conditions suitable for expression, the receptor protein or polypeptide is produced. The construct can be introduced into cells by a method appropriate to the host cell selected transformation, transfection, electroporation, infection). For production of receptor, host cells comprising the construct are maintained under conditions appropriate for expression, in the presence of inducer n-butyrate), suitable media supplemented with appropriate salts, growth factors, antibiotic, nutritional supplements, etc.

Antibodies The invention further relates to antibodies reactive with a CKR-3 receptor or portion thereof. In one embodiment, antibodies are raised against an isolated and/or recombinant mammalian CKR-3 protein including portions thereof a peptide). In a preferred embodiment, the antibodies specifically bind CKR-3 receptor(s) or a portion thereof.

The antibodies of the present invention can be 30 polyclonal or monoclonal (see Example and the term antibody is intended to encompass both polyclonal and monoclonal antibodies. Antibodies of the present invention can be raised against an appropriate immunogen, including proteins or polypeptides of the present invention, such as -32isolated and/or recombinant mammalian CKR-3 receptor protein or portion thereof, or synthetic molecules, such as synthetic peptides. In addition, cells which express receptor, such as transfected cells, can be used as immunogens or in a screen for antibody which binds receptor. See for example, Chuntharapai et al., J.

Immunol. 152: 1783-1789 (1994)).

Preparation of immunizing antigen, and polyclonal and monoclonal antibody production can be performed using any suitable technique. A variety of methods have been described (see Kohler et al., Nature, 256: 495-497 (1975) and Eur J. mmunol. 6: 511-519 (1976); Milstein et al., Nature 266: 550-552 (1977); Koprowski et al., U.S.

Patent No. 4,172,124; Harlow, E. and D. Lane, 1988, Antibodies: A Laboratory Manual, (Cold Spring Harbor Laboratory: Cold Spring Harbor, NY); Current Protocols In Molecular Biology, Vol. 2 (Supplement 27, Summer '94), Ausubel, F.M. et al., Eds., (John Wiley Sons: New York, NY), Chapter 11, (1991)). Generally, a hybridoma is produced by fusing a suitable immortal cell line a myeloma cell line such as SP2/0) with antibody producing cells. The antibody producing cell, preferably those of the spleen or lymph nodes, are obtained from animals immunized with the antigen of interest. The fused cells (hybridomas) are isolated using selective culture conditions, and cloned by limiting dilution. Cells which produce antibodies with the desired specificity are selected by a suitable assay

ELISA).

Single chain antibodies, and chimeric, humanized or 30 primatized (CDR-grafted) antibodies, as well as chimeric or CDR-grafted single chain antibodies, comprising portions derived from different species, are also encompassed by the present invention and the term "antibody". The various portions of these antibodies can be joined together chemically by conventional techniques, or can be prepared .e -33as a contiguous protein using genetic engineering techniques. For example, nucleic acids encoding a chimeric or humanized chain can be expressed to produce a contiguous protein. See, Cabilly et al., U.S. Patent No.

4,816,567; Cabilly et al., European Patent No. 0,125,023 B1; Boss et al., U.S. Patent No. 4,816,397; Boss et al., European Patent No. 0,120,694 Bl; Neuberger, M.S. et al., WO 86/01533; Neuberger, M.S. et al., European Patent No.

0,194,276 Bl; Winter, U.S. Patent No. 5,225,539; and Winter, European Patent No. 0,239,400 Bl. See also, Newman, R. et al., BioTechnology, 10: 1455-1460 (1992), regarding primatized antibody, and Ladner et al., U.S.

Patent No. 4,946,778 and Bird, R.E. et al., Science, 242: 423-426 (1988)) regarding single chain antibodies.

In addition, functional fragments of antibodies, including fragments of chimeric, humanized, primatized or single chain antibodies, can also be produced. Functional fragments of foregoing antibodies retain at least one binding function and/or modulation function of the fulllength antibody from which they are derived. For example, antibody fragments capable of binding to a mammalian CKR-3 receptor or portion thereof, including, but not limited to, Fv, Fab, Fab' and F(ab') 2 fragments are encompassed by the invention. Such fragments can be produced by enzymatic cleavage or by recombinant techniques. For instance, papain or pepsin cleavage can generate Fab or F(ab') 2 fragments, respectively. Alternatively, antibodies can be produced in a variety of truncated forms using antibody genes in which one or more stop codons has been introduced 30 upstream of the natural stop site. For example, a chimeric .gene encoding a F(ab') 2 heavy chain portion can be designed to include DNA sequences encoding the CH, domain and hinge region of the heavy chain.

-34- The antibodies of the present invention are useful in a variety of applications, including research, diagnostic and therapeutic applications. For instance, they can be used to isolate and/or purify receptor or portions thereof, and to study receptor structure conformation) and function.

The antibodies of the present invention can also be used to modulate receptor function in research and therapeutic applications. For instance, antibodies can act as inhibitors to inhibit (reduce or prevent) binding of a ligand, a second inhibitor or a promoter) to the receptor, a receptor signalling, and/or a stimulatory function. Antibodies which act as inhibitors of receptor function can block ligand or promoter binding directly or indirectly by causing a conformational change). For example, antibodies can inhibit receptor function by inhibiting binding of a ligand, or by desensitization (with or without inhibition of binding of a ligand).

Antibodies which bind receptor can also act as agonists of receptor function, triggering or stimulating a receptor function, such as a signalling and/or a stimulatory function of a receptor chemotaxis, exocytosis or pro-inflammatory mediator release) upon binding to receptor.

In addition, the various antibodies of the present invention can be used to detect or measure the expression of receptor, for example, on leukocytes such as 9:2 eosinophils, basophils, and lymphocytes, or on cells 30 transfected with a receptor gene. Thus, they also have utility in applications such as cell sorting flow cytometry, fluorescence activated cell sorting), for diagnostic or research purposes.

o *Anti-idiotypic antibodies are also provided. Anti- 35 idiotypic antibodies recognize antigenic determinants 9* 9.9.

associated with the antigen-binding site of another antibody. Anti-idiotypic antibodies can be prepared a against second antibody by immunizing an animal of the same species, and preferably of the same strain, as the animal used to produce the second antibody. See U.S. Patent No. 4,699,880.

In one embodiment, antibodies are raised against receptor or a portion thereof, and these antibodies are used in turn to produce an anti-idiotypic antibody. The anti-Id produced thereby can bind compounds which bind receptor, such as ligands, inhibitors or promoters of receptor function, and can be used in an immunoassay to detect or identify or quantitate such compounds. Such an anti-idiotypic antibody can also be an inhibitor of receptor function, although it does not bind receptor itself.

Anti-idiotypic Anti-Id) antibody can itself be used to raise an anti-idiotypic antibody Anti-anti-Id). Such an antibody can be similar or identical in specificity to the original immunizing antibody. In one embodiment, antibody antagonists which block binding to receptor can be used to raise Anti-Id, and the Anti-Id can be used to raise Anti-anti-Id, which can have a specificity which is similar or identical to that of the antibody antagonist. These anti-anti-Id antibodies can be assessed for inhibitory effect on receptor function to determine if they are antagonists.

S

Single chain, and chimeric, humanized or primatized (CDR-grafted), as well as chimeric or CDR-grafted single 30 chain anti-idiotypic antibodies can be prepared, and are encompassed by the term anti-idiotypic antibody. Antibody fragments of such antibodies can also be prepared.

a.

-36- Identification of Liaands. Inhibitors or Promoters of Recentor Function As used herein, a ligand is a substance which binds to a receptor protein. A ligand of a selected mammalian CKR-3 receptor is a substance which binds to the selected mammalian receptor. In one embodiment, a ligand can bind selectively to two or more mammalian chemokine receptors, including CKR-3. In a preferred embodiment, ligand binding of a mammalian CKR-3 receptor occurs with high affinity.

The term ligand refers to substances including, but not limited to, a natural ligand, whether isolated and/or purified, synthetic, and/or recombinant, a homolog of a natural ligand from another mammal), antibodies, portions of such molecules, and other substances which bind receptor. A natural ligand of a selected mammalian receptor can bind to the receptor under physiological conditions, and is of a mammalian origin which is the same as that of the mammalian CKR-3 receptor. The term ligand encompasses substances which are inhibitors or promoters of receptor activity, as well as substances which bind but lack inhibitor or promoter activity.

As used herein, an inhibitor is a substance which inhibits at least one function characteristic of a mammalian C-C chemokine receptor a mammalian CKR-3 receptor), such as a binding activity ligand, inhibitor and/or promoter binding), a signalling activity activation of a mammalian G protein, induction of rapid and transient increase in the concentration of cytosolic free calcium [Ca 2 and/or stimulation of a cellular response. The term inhibitor refers to substances including antagonists which bind receptor an antibody, a mutant of a natural ligand, other competitive inhibitors of ligand binding), and substances which inhibit t.* -37receptor function without binding thereto an anti-idiotypic antibody).

As used herein, a promoter is a substance which promotes (induces or enhances) at least one function characteristic of a mammalian C-C chemokine receptor a mammalian CKR-3 receptor), such as a binding activity ligand, inhibitor and/or promoter binding), a signalling activity activation of a mammalian

G

protein, induction of rapid and transient increase in the concentration of cytosolic free calcium [Ca 2 and/or stimulation of a cellular response. The term promoter refers to substances including agonists which bind receptor an antibody, a homolog of a natural ligand from another species),.and substances which promote receptor function without binding thereto by activating an associated protein).

The assays described below, which rely upon the nucleic acids and proteins of the present invention, can be used, alone or in combination with each other or other suitable methods, to identify ligands, inhibitors or promoters of a mammalian CKR-3 receptor protein or polypeptide. Human CKR-3 does not usually exist in cells at levels suitable for high-throughput screening; thus, cells which contain and express a nucleic acid of the present invention are particularly valuable in identifying ligands, inhibitors and promoters of CKR-3 receptor proteins.

Upon isolation of a CKR-3 receptor gene from a mammal, the gene can be incorporated into an expression system to 30 produce a receptor protein or polypeptide as described above. An isolated and/or recombinant receptor protein or polypeptide, such as a receptor expressed in cells stably or transiently transfected with a construct comprising a nucleic acid of the present invention, or in a cell -38fraction membrane fraction from transfected cells) containing receptor, can be used in tests for receptor function. The receptor can be further purified if desired.

Testing of receptor function can be carried out in vitro or in vivo.

An isolated, recombinant mammalian CKR-3 receptor protein, such as a human CKR-3 receptor as that shown in Figure 1A-1C (see also, SEQ ID NO:2), Figure 2A-2B (see also, SEQ ID NO:4) or SEQ ID NO:6, can be used in the present method, in which the effect of a compound is assessed by monitoring receptor function as described herein or using other suitable techniques. For example, stable or transient transfectants, such as A31/293/#2 0 stable transfectants (see Example stable tranfectants of mouse L1-2 pre-B cells (see Example baculovirus infected Sf9 cells (see Example 4), can be used in binding assays. Stable transfectants of mouse L1-2 pre-B cells or of other suitable cells capable of chemotaxis can be used (see Example 3) in chemotaxis assays, for example.

According to the method of the present invention, compounds can be individually screened or one or more compounds can be tested simultaneously according to the methods herein. Where a mixture of compounds is tested, the compounds selected by the processes described can be separated (as appropriate) and identified by suitable methods PCR, sequencing, chromatography). The presence of one or more compounds a ligand, inhibitor, promoter) -in a test sample can also be 30 determined according to these methods.

Large combinatorial libraries of compounds organic compounds, recombinant or synthetic peptides,, "peptoids", nucleic acids) produced by combinatorial chemical synthesis or other methods can be tested (see 35 Zuckerman, R.N. et al., J. Med. Chem., 37: 2678-2685 -39- (1994) and references cited therein; see also, Ohlmeyer, M.H.J. et al., Proc. Natl. Acad. Sci. USA 90:10922-10926 (1993) and DeWitt, S.H. et al., Proc. Natl. Acad. Sci. USA 90:6909-6913 (1993), relating to tagged compounds; Rutter, W.J. et al. U.S. Patent No. 5,010,175; Huebner, V.D. et al., U.S. Patent No. 5,182,366; and Geysen,

U.S.

Patent No. 4,833,092). Where compounds selected from a combinatorial library by the present method carry unique tags, identification of individual compounds by chromatographic methods is possible.

In one embodiment, phage display methodology is used.

For example, receptor is contacted with a phage a phage or collection of phage such as a library) displaying a polypeptide under conditions appropriate for receptor binding in a suitable binding buffer). Phage bound to receptor is selected using standard techniques or other suitable methods. Phage can be separated from receptor using a suitable elution buffer. For example, a change in the ionic strength or pH can lead to a release of phage.

Alternatively, the elution buffer can comprise a release component or components designed to disrupt binding of compounds one or more compounds which can disrupt binding of the displayed peptide to the receptor, such as a ligand, inhibitor, and/or promoter which competitively 25 inhibits binding). Optionally, the selection process can S be repeated or another selection step can be used to further enrich for phage which bind receptor. The displayed polypeptide is characterized by sequencing phage DNA). The polypeptides identified can be produced and further tested for ligand binding, inhibitor and/or promoter function. Analogs of such peptides can be produced which will have increased stability or other desirable properties.

In one embodiment, phage expressing and displaying a 35 fusion proteins comprising a coat protein with an Nterminal peptide encoded by random sequence nucleic acids can be produced. Suitable host cells expressing a receptor protein or polypeptide of the present invention are contacted with the phage, bound phage are selected, recovered and characterized. (See Doorbar, J. and G.

Winter, J. Mol. Biol., 244: 361 (1994) discussing a phage display procedure used with a G protein-coupled receptor).

Other sources of potential ligands, inhibitors and/or promoters of a mammalian CKR-3 receptor include, but are not limited to, substances such as other chemoattractants anaphylatoxin C5a and bacterial formylated: tripeptide (fMLP)); other chemokines eotaxin), such as a mammalian chemokine from the same mammal as the receptor, from another mammal for a human receptor a homolog of a human chemokine obtained from a non-human source); variants of other chemoattractants or chemokines, such as naturally occurring, synthetic or recombinant variants; other mammalian CKR-3 receptor ligands, inhibitors and/or promoters antibodies, antagonists, agonists), and variants thereof; other G-protein coupled receptor ligands, inhibitors and/or promoters antagonists or agonists); and soluble portions of a mammalian CKR-3 receptor, such as a suitable receptor peptide or analog which can inhibit receptor function (see 25 Murphy, WO 94/05695).

The in vitro method of the present invention can be used in high-throughput screening. These assays can be adapted for processing large numbers of samples a 96 well format). For such screening, use of a host cell expressing receptor, instead of isolated eosinophils, is preferred because of the difficulty in isolating eosinophils.

For binding assays, high level expression of receptor in a suitable host cell is preferred. Expression of 35 receptor can be monitored in a variety of ways. For eo -41instance, expression can be monitored using antibodies of the present invention which bind receptor or a portion thereof. Also, commercially available antibodies can be used to detect expression of an antigen- or epitope-tagged fusion protein comprising a receptor protein or polypeptide FLAG tagged receptors; see Example 3).

BindinG Assays The isolated and/or recombinant receptor proteins, portions thereof, or suitable fusion proteins of the present invention, can be used in a method to select and identify compounds which bind to a (one or more) mammalian CKR-3 receptor protein, such as human CKR-3 receptor, and which are ligands, or potential inhibitors or promoters of receptor activity. Compounds selected by the method, including ligands, inhibitors or promoters, can be further assessed for an inhibitory or stimulatory effect on receptor function and/or for therapeutic utility.

In one embodiment, compounds which bind to an active, isolated and/or recombinant mammalian CKR-3 receptor protein or polypeptide are identified by the method. In this embodiment, the receptor protein or polypeptide used has at least one function characteristic of a CKR-3 receptor, such as a signalling activity activation of a mammalian G protein), stimulatory function i 25 stimulation of chemotaxis or inflammatory mediator release), and/or binding function ligand, inhibitor and/or promoter binding). In a particularly preferred embodiment, the isolated and/or recombinant mammalian CKR-3 receptor protein or polypeptide has ligand binding 30 function, such that it binds a natural ligand of the receptor.

For example, an isolated and/or recombinant mammalian CKR-3 receptor protein or polypeptide can be maintained under conditions suitable for binding, the receptor is *oo -42contacted with a compound to be tested, and binding is detected or measured. In one embodiment, a receptor protein can be expressed in cells stably or transiently transfected with a construct comprising a nucleic acid sequence which encodes a receptor of the present invention.

The cells are maintained under conditions appropriate for expression of receptor. The cells are contacted with a compound under conditions suitable for binding in a suitable binding buffer), and binding is detected by standard techniques. To measure binding, the extent of binding can be determined relative to a suitable.control compared with background determined in the absence of compound, compared with binding of a second compound a standard), compared with binding of compound to untransfected cells). Optionally, a cellular fraction, such as a membrane fraction, containing receptor can be used in lieu of whole cells (see Example 9).

In one embodiment, the compound is labeled with a suitable label fluorescent label, isotope label), and binding is determined by detection of the label.

Specificity of binding can be assessed by competition or displacement, for example, using unlabeled compound or a second ligand as competitor.

Ligands of the mammalian receptor, including natural ligands from the same mammalian species or from another Sspecies, can be identified in this manner. The binding activity of a promoter or inhibitor which binds receptor can also be assessed using such a ligand binding assay.

Binding inhibition assays can also be used to identify 30 ligands, and inhibitors and promoters which bind receptor and inhibit binding of another compound such as a ligand.

For example, a binding assay can be conducted in which a reduction in the binding of a first compound (in the absence of a second compound), as compared binding of the 35 first compound in the presence of the second compound, is *.iii 'o'°o -43detected or measured. The receptor can be contacted with the first and second compounds simultaneously, or one after the other, in either order. A reduction in the extent of binding of the first compound in the presence of the second compound, is indicative of inhibition of binding by the second compound. For example, binding of the first compound could be decreased or abolished.

In one embodiment, direct inhibition of the binding of a first compound a chemokine such as RANTES) to a human CKR-3 receptor by a second test compound is monitored. For example, the ability of a compound to inhibit the binding of 1 5I-labeled RANTES or 1 I-labeled MCP-3 to human CKR-3 can be monitored. Such an assay can be conducted using either whole cells butyric aciddifferentiated HL-60 cells, or a suitable cell line containing nucleic acid encoding a human CKR-3 receptor) or a membrane fraction from said cells, for instance.

Other methods of identifying the presence of a compound(s) which bind a receptor are available, such as methods which monitor events which are triggered by receptor binding, including signalling function and/or stimulation of a cellular response (See below).

It will be understood that the inhibitory effect of antibodies of the present invention can be assessed in a binding inhibition assay. Competition between antibodies for receptor binding can also be assessed in the method in which the first compound in the assay is another antibody, S...under conditions suitable for antibody binding.

S. Ligands, as well as receptor-binding inhibitors 30 antagonists) and promoters agonists), which are identified in this manner, can be further assessed to determine whether, subsequent to binding, they act to inhibit or activate other functions of CKR-3 receptors and/or to assess their therapeutic utility.

*o* -44- Sianalline Assays The binding of a ligand or promoter, such as an agonist, can result in signalling by a G protein-coupled receptor, and the activity of G proteins is stimulated.

The induction of induce signalling function by a compound can be monitored using any suitable method. For example,

G

protein activity, such as hydrolysis of GTP to GDP, or later signalling events triggered by receptor binding, such as induction of rapid and transient increase in the concentration of intracellular (cytosolic) free calcium [Ca 2 can be assayed by methods known in the art or other suitable methods (see Neote, K. et al., Cell, 72: 415-425 1993); Van Riper et al., J. Exp. Med., 177: 851-856 (1993); Dahinden, C.A. et al., J. Exp. Med., 179: 751-756 (1994).

The functional assay of Sledziewski et al. using hybrid G protein coupled receptors can also be used to monitor the ability a ligand or promoter to bind receptor and activate a G protein (Sledziewski et al., U.S. Patent No. 5,284,746, the teachings of which are incorporated herein by reference).

A biological response of the host cell (triggered by binding to hybrid receptor) is monitored, detection of the response being indicative of the presence of ligand in the test sample. Sledziewski et al. describes a method of detecting the presence of a ligand in a test sample, wherein the ligand is a compound which is capable-of being bound by the ligand-binding domain of a receptor. In one o embodiment of.the method, yeast host cells are transformed 30 with a DNA construct capable of directing the expression of a biologically active hybrid G protein-coupled receptor a fusion protein). The hybrid receptor comprises a mammalian G protein-coupled receptor having at least one domain other than the ligand-binding domain replaced with a corresponding domain of a yeast G protein-coupled receptor, such as a STE2 gene product. The yeast host cells containing the construct are maintained under conditions in which the hybrid receptor is expressed, and the cells are contacted with a test sample under conditions suitable to permit binding of ligand to the hybrid receptor. The assay is conducted as described and the biological response of the host cell (triggered by binding to hybrid receptor) is monitored, detection of the response being indicative of a signalling function.

For instance, an assay is provided in which binding to a hybrid receptor derived from STE2 gene product leads to induction of the BAR1 promoter. Induction of the promoter is measured by means of a reporter gene (0-gal), which is linked to the BAR1 promoter and introduced into host cells on a second construct. Expression of the reporter gene can be detected by an in vitro enzyme assay on cell lysates or by the presence of blue colonies on plates containing an indicator (X-gal) in the medium, for example.

In another embodiment, the assay is used to identify potential inhibitors of receptor function. The inhibitory activity of a compound can be determined using a ligand or promoter in the assay, and assessing the ability of the compound to inhibit the activity induced by ligand or promoter.

Variants of known ligands can also be screened for reduced ability (decreased ability or no ability) to stimulate activity of a coupled G protein. In this embodiment, although the compound has ligand binding 30 activity (as determined by another method in advance or later), engagement of the receptor does not trigger or only weakly triggers activity of a coupled G protein. Such compounds are potential antagonists, and can be further assessed using a suitable assay. For instance, the same assay can be conducted in the presence of a ligand or -46promoter, and the ability of the compound to inhibit the activity of a ligand or promoter is assessed.

Chemotaxis and Assays of Cellular Stimulation Chemotaxis assays can also be used to assess receptor function. These assays are based on the functional migration of cells in vitro or in vivo induced by a compound, and can be used to assess the binding and/or chemoattractant effect of ligands, inhibitors, or promoters. The use of an in vitro transendothelial chemotaxis assay is described in Example i. Springer et al. describe a transendothelial lymphocyte chemotaxis assay (Springer et al., WO 94/20142, published September 1994, the teachings of which are incorporated herein by reference; see also Berman et al., Immunol Invest. 17: 625- 677 (1988)). Migration across endothelium into collagen gels has also been described (Kavanaugh et al., J. Immunol, 146: 4149-4156 (1991)).

Stable transfectants of mouse L1-2 pre-B cells or of other suitable host cells capable of chemotaxis can be used (see Example 3) in chemotaxis assays, for example.

As is further described herein eosinophilic-like cell lines, such as the butyrate differentiated HL60 line which elaborates a CKR-3 receptor, can also be incorporated into chemotaxis assays.

Generally, chemotaxis assays monitor the directional movement or migration of a suitable cell (such as a leukocyte lymphocyte, eosinophil, basophil)) into or through a barrier endothelium, a filter), toward increased levels of a compound, from a first surface of the *30 barrier toward an opposite second surface. Membranes or filters provide convenient barriers, such that the directional movement or migration of a suitable cell into or through a filter, toward increased levels of a compound, from a first surface of the filter toward an opposite oooo ooo go *o *ooo* *•ooo -47second surface of the filter, is monitored. In some assays, the membrane is coated with a substance to facilitate adhesion, such as ICAM-1, fibronectin or collagen.

For example, one can detect or measure the migration of cells in a suitable container (a containing means), from a first chamber into or through a microporous membrane into a second chamber which contains a compound to be tested, and which is divided from the first chamber by the membrane. A suitable membrane, having a suitable pore size for monitoring specific migration in response to compound, including, for example,' nitrocellulose, polycarbonate, is selected. For example, pore sizes of about 3-8 microns, and preferably about 5-8 microns can be used. Pore size can be uniform on a filter or within a range of suitable pore sizes.

To assess migration, the distance of migration into the filter, the number of cells crossing the filter that remain adherent to the second surface of the filter, and/or the number of cells that accumulate in the second chamber can be determined using standard techniques microscopy). In one embodiment, the cells are labeled with a detectable label radioisotope, fluorescent label, antigen or epitope label), and migration can be assessed by determining the presence of the label adherent to the membrane and/or present in the second chamber using an appropriate method by detecting radioactivity fluorescence, immunoassay). The extent of migration induced by a compound can be determined relative to a :30 suitable control compared to background migration determined in the absence of the compound, to the extent of migration induced by a second compound a standard), compared with migration of untransfected cells induced by the compound).

-48- Chambers can be formed from various solids, such as plastic, glass, polypropylene, polystyrene, etc. Membranes which are detachable from the chambers, such as a Biocoat (Collaborative Biomedical Products) or Transwell (Costar, Cambridge, MA) culture insert, facilitate counting adherent cells.

In the container, the filter is situated so as to be in contact with fluid containing cells in the first chamber, and the fluid in the second chamber. Other than the test compound or additional ligand, inhibitor, or promoter present for the purpose of the assay, the fluid on either side of the membrane is preferably the same or substantially similar. The fluid in the chambers can comprise protein solutions bovine serum albumin, fetal calf serum, human serum albumin) which may act to increase stability and inhibit nonspecific binding of cells, and/or culture media.

In a preferred embodiment, particularly for eosinophils, eosinophil-like cells, lymphocytes, or cells expressing a CKR-3 receptor, transendothelial migration is monitored. A transendothelial migration assay is preferred. Such assays are better physiological models, because they more accurately recapitulate in vivo conditions in which leukocytes emigrate from blood vessels toward chemoattractants present in the tissues at sites of inflammation by crossing the endothelial cell layer lining the vessel wall. In addition, transendothelial assays have lower background (signal to noise ratio).

In this embodiment, transmigration through an endothelial cell layer assessed. To prepare the cell Slayer, endothelial cells can be cultured on a microporous filter or membrane, optionally coated with a substance such as collagen, fibronectin, or other extracellular matrix proteins, to facilitate the attachment of endothelial S 35 cells. Preferably, endothelial cells are cultured until a -49confluent monolayer is formed. A variety of mammalian endothelial cells can are available for monolayer formation, including for example, vein, artery or microvascular endothelium, such as human umbilical vein endothelial cells (Clonetics Corp, San Diego, CA) or a suitable cell line, such as the ECV 304 cell line used in Example 1. To assay chemotaxis in response to a particular mammalian receptor, endothelial cells of the same mammal are preferred; however endothelial cells from a heterologous mammalian species or genus can also be used.

Generally, the assay is performed by detecting the directional migration of cells into or through a membrane or filter, in a direction toward increased levels of a compound, from a first surface of the filter toward an opposite second surface of the filter, wherein the filter contains an endothelial cell layer on a first surface.

Directional migration occurs from the area adjacent to the first surface, into or through the membrane, towards a compound situated on the opposite side of the filter. The concentration of compound present in the area adjacent to the second surface, is greater than that in the area adjacent to the first surface.

In one embodiment, a chemotaxis is used to test for ligand or promoter activity of a compound, a composition comprising cells capable of migration and expressing a mammalian CKR-3 receptor are placed in the first chamber, and a composition comprising the compound to be tested is placed in the second chamber, preferably in the absence of other ligands or promoters capable of inducing chemotaxis 30 of the cells in the first chamber (having chemoattractant function). However, one or more ligands or promoters having chemoattractant function may be present. Compounds which can bind receptor and induce chemotaxis of the cells expressing a mammalian CKR-3 receptor in this assay are ligands or promoters of receptor function.

In one embodiment used to test for an inhibitor, a composition comprising cells capable of migration and expressing a mammalian CKR-3 receptor are placed in the first chamber. A composition comprising one or more ligands or promoters capable of inducing chemotaxis of the cells in the first chamber (having chemoattractant function) is placed in the second chamber. Either shortly before the cells are placed in the first chamber, or simultaneously with the cells, a composition comprising the compound to be tested is placed, preferably, in the first chamber. Compounds which can bind receptor and inhibit the induction of chemotaxis, by a ligand or promoter, of the cells expressing a mammalian CKR-3 receptor in this assay are inhibitors of receptor function inhibitors of stimulatory function). A reduction in the extent of migration induced by the ligand or promoter in the presence of the test compound, is indicative of inhibitory activity.

(see Example Separate binding studies (see above) could be performed to determine whether inhibition is a result of binding of the test compound to receptor or occurs via a different mechanism.

In vivo assays which monitor leukocyte infiltration of a tissue, in response to injection of a compound in the tissue, are described below (see Models of Inflammation).

These models measure the ability of cells to respond to a ligand or promoter by emigration and chemotaxis to a site of inflammation.

In addition to the methods described, the effects of a ligand, inhibitor or promoter on the stimulatory function 30 of the receptor can be assessed by monitoring cellular responses induced by active receptor, using suitable host cells containing receptor. Similarly, these assays can be used to determine the function of a receptor. For instance, exocytosis degranulation of eosinophils 35 leading to release of eosinophil cationic protein and/or e -51one or more enzymes, or other granule components; release of histamine from basophils), inflammatory mediator release (such as release of bioactive lipids such as leukotrienes leukotriene

C

4 and respiratory burst (Rot, A. et al., J. Exp. Med., 176: 1489-1495 (1992)), can be monitored by methods known in the art or other suitable methods. See Bischoff. S.C. et al., Eur. J. Immunol., 23: 761-767 (1993) and Baggliolini, M. and C.A. Dahinden, Immunology Today, 15: 127-133 (1994) and references cited therein).

In one embodiment, a ligand, inhibitor and/or promoter is identified by monitoring the release of an enzyme upon degranulation or exocytosis by a cell capable of this function. Cells containing a nucleic acid of the present invention, which encodes an active receptor protein capable of stimulating exocytosis or degranulation are maintained in a suitable medium under suitable conditions, whereby receptor is expressed and degranulation can be induced.

The receptor is contacted with a compound to be tested, and enzyme release is assessed. The release of an enzyme into the medium can be detected or measured using a suitable assay, such as in an immunological assay, or biochemical assay for enzyme activity.

The medium can be assayed directly, by introducing components of the assay substrate, co-factors, antibody) into the medium before, simultaneous with or after the cells and compound are combined).

.Alternatively, the assay can be performed on medium which has been separated from the cells or further fractionated prior to assay.

30 For example, convenient assays for are available for enzymes such as f-glucuronidase and eosinophil peroxidase (White, S.R. et al., A kinetic assay for eosinophil peroxidase activity in eosinophils and eosinophil *oo *o -52conditioned media, J. Immunol. Methods, 144(2): 257-63 (1991)).

Stimulation of degranulation by a compound can be indicative that the compound is a ligand or promoter of a mammalian CKR-3 receptor. In another embodiment, inhibition of degranulation is indicative of an inhibitor.

In this embodiment, the cells expressing receptor are combined with a ligand or promoter, and a compound to be tested is added before, after or simultaneous therewith.

Models of Inflammation A variety of in vivo models of inflammation are available, which can be used to assess the effects of ligands, inhibitors, or promoters in vivo as therapeutic agents.

For example, primate models with eosinophilic infiltration to the lung, are available for in vivo testing (see Wegner, C.D. et al., Science, 247: 456 (1990)).

In one embodiment, an antibody a monoclonal antibody) which reacts with human CKR-3, and which crossreacts with primate CKR-3, is administered to the animal.

A number of parameters can be measured to assess in vivo efficacy including, but not limited to, the number of eosinophils in broncoalveolar lavage fluid, respiratory compliance, and respiratory rate. A decrease in symptoms of airway hypersensitivity is indicative of therapeutic benefit.

In addition, a sheep model for asthma, a guinea pig model for passive cutaneous anaphylaxis, or other suitable model can be used to assess compounds in vivo (see e.g., 30 Weg, V.B. et al., J. Exp. Med., 177: 561 (1993); Abraham, W.M. et al., J. Clin. Invest., 93: 776 (1994)).

In addition, leukocyte infiltration upon intradermal injection of a compound into a suitable animal, such as rabbit, rat, or guinea pig, can be monitored (see Van -53- Damme j. et al., J. Exp. Med., 176: 59-65 (1992); Zachariae, C.O.C. et al., j. Exp. Med. 171: 2177-2182 (1990); Jose, P.J. et al., J. Exp. Med. 179: 881-887 (1994)). In one embodiment, skin biopsies are assessed histologically for infiltration of leukocytes eosinophils, granulocytes). In another embodiment, labeled cells stably transfected cells expressing a CKR-3 receptor, labeled with i"In for example) capable of chemotaxis and extravasation are administered to the animal. Infiltration of cells in response to injection of a test sample a compound to be tested in a suitable buffer or physiological carrier) is indicative of the presence of a ligand or promoter, such as an agonist, in the sample. These assays can also be modified to identify inhibitors of chemotaxis and leukocyte extravasation. For example, an inhibitor can be administered, either before, simultaneously with or after ligand or agonist is administered to the test animal. A decrease of the extent of infiltration in the presence of inhibitor as compared with the extent of infiltration in the absence of inhibitor is indicative of inhibition.

Diagnostic Applications The present invention has a variety of diagnostic applications. These applications include, but are not necessarily limited to the applications discussed herein.

Mutation(s) in genes encoding a mammalian CKR-3 receptor protein can cause defects .in at least one function of the encoded receptor, thereby reducing or enhancing S receptor function. For instance, mutations which produce a 30 variant of receptor or alter the level of expression, can reduce or enhance receptor function, reducing or enhancing, the inflammatory processes mediated by receptor.

-54- For example, the methods of detecting or measuring receptor function can be used to characterize the activity of receptors in cells leukocytes) of an individual or of receptors isolated from such cells. In these assays, reduced or enhanced receptor function can be assessed.

The nucleic acids of the present invention provide reagents probes, PCR primers) which can be used to screen for, characterize and/or isolate a defective mammalian CKR-3 receptor gene, which encodes a receptor having reduced or enhanced activity. Standard methods of screening for a defective gene can be employed, for instance. A defective gene and the activity of the encoded receptor can be isolated and expressed in a suitable host cell for further assessment as described herein for mammalian CKR-3 receptors. A number of human diseases are associated with defects in the function of a G-protein coupled receptor (Clapham, Cell, 75: 1237-1239 (1993); Lefkowitz, Nature, 365: 603-04 (1993)).

The antibodies of the present invention have application in procedures in which receptor can be detected on the surface of cells. The receptor provides a marker of the leukocyte cell types in which it is expressed, particularly in eosinophils. For example, antibodies raised against a receptor protein or peptide can be used to count cells expressing receptor. Cell counts can be used in the diagnosis of a variety of diseases or conditions in which increased or decreased leukocyte cell types. hypereosinophilia, for example in hypereosinophilic syndrome; hypoeosinophilia) are observed. The presence of 30 an increased level of eosinophils in a sample obtained from an individual can be indicative of eosinophil infiltration due to an inflammatory disease or condition, such as S. .asthma, or an infection such as a parasitic infections.

Alternatively, or in addition, the antibodies can be used to sort cells which express receptor from among a mixture o* ooo* o 0 go o *O* go of cells. Suitable methods for counting and/or sorting cells can be used for this purpose flow cytometry, fluorescence activated cell sorting).

Furthermore, the antibodies can be used to detect or measure decreased or increased expression of receptor in various diseases or conditions in which inflammatory processes of leukocytes are altered increased or decreased relative to a suitable control, such as the level of expression in a normal individual). For example, leukocytes eosinophils, lymphocytes such as T lymphocytes, monocytes, basophils) can be obtained from an individual and a suitable immunological assay

ELISA,

FACS analysis) can be used to assess the level of expression. The level of expression of a mammalian CKR-3 receptor can be used in the diagnosis of a disease or condition in which increased or decreased expression of a mammalian CKR-3 receptor is present.

Transqenic Animals Transgenic animals, in which the genome of the animal host is altered using recombinant DNA techniques, can be constructed. In one embodiment, the alteration is not heritable somatic cells, such as progenitor cells in bone marrow, are altered). In another embodiment, the alteration is heritable (the germ line is altered).

25 Transgenic animals can be constructed using standard techniques or other suitable methods (see Cooke. M.P.

et al., Cell, 65: 281-291 (1991) regarding alteration of T lymphocytes; Hanahan, Science, 246: 1265-1275, (1989)).

In one aspect, an endogenous mammalian CKR-3 receptor gene can be inactivated or disabled, in whole or in part, in a suitable animal host by gene disruption techniques) to produce a transgenic animal. Nucleic acids of the present invention can be used to assess successful construction of a host containing an inactivated or -56disabled CKR-3 gene by Southern hybridization). In addition, successful construction of a host containing an inactivated or disabled CKR-3 gene can be assessed by suitable assays which monitor the function of the encoded receptor.

In another embodiment, a nucleic acid encoding a mammalian CKR-3 receptor protein or polypeptide is introduced into a suitable host to produce a transgenic animal. In a preferred embodiment, endogenous CKR-3 receptor genes present in the transgenic animals are inactivated simultaneously with introduction of the nucleic acid by homologous recombination, which disrupts and replaces the endogenous gene). For example, a transgenic animal a mouse, guinea pig, sheep) capable of expressing a nucleic acid encoding a mammalian CKR-3 receptor of a different mammalian species a human) in leukocytes (such as eosinophils, lymphocytes T lymphocytes) can be produced, and provides a convenient animal model for assessing the function of the introduced receptor. In addition, a compound can be administered to the transgenic animal, and the effect of the compound on an inflammatory process mediated by receptor can be monitored in a suitable assay ((see e.g., Weg, V.B. et al., J. Exp. Med., 177: 561 (1993); Abraham, W.M. et al., J. Clin. Invest., 93: 776 (1994)). In this manner, compounds which inhibit or promote receptor function can be identified or assessed for in vivo effect.

Methods of Therapy Modulation of mammalian CKR-3 receptor function according to the present invention, through the inhibition or promotion of at least one function characteristic of a mammalian CKR-3 receptor, provides an effective and selective way of inhibiting or promoting leukocyte-mediated inflammatory action. One or more ligands, inhibitors o o S -57and/or promoters of CKR-3 receptor function, such as those identified as described herein, can be used to modulate leukocyte function for therapeutic purposes.

As major eosinophil and lymphocyte chemokine receptors, mammalian CKR-3 receptors provide a target for interfering with or promoting eosinophil and/or lymphocyte function in a mammal, such as a human. Consistently, co-localization of T cells and eosinophils is observed in certain inflammatory infiltrates. Thus, compounds which inhibit or promote CKR-3 receptor function, such as ligands, inhibitors and promoters identified according to the present method, are particularly useful for modulating eosinophil and/or lymphocyte function for therapeutic purposes.

Thus, the present invention provides a method of inhibiting or promoting an inflammatory response in an individual in need of such therapy, comprising administering a compound which inhibits or promotes mammalian CKR-3 receptor function to an individual in need of such therapy.

In one embodiment, a compound which inhibits one or more functions of a mammalian CKR-3 receptor a human CKR-3 receptor) is administered to inhibit reduce or prevent) inflammation. As a result, one or more inflammatory processes, such as leukocyte emigration, chemotaxis, exocytosis of enzymes, histamine} or inflammatory mediator release, is inhibited. For example, eosinophilic infiltration to inflammatory sites in asthma) can be inhibited according to the present method.

30 In another embodiment, a compound which promotes one or more functions of a mammalian CKR-3 receptor a human CKR-3 receptor) is administered to stimulate (induce or enhance) an inflammatory response, such as leukocyte emigration, chemotaxis, exocytosis of enzymes, histamine) or inflammatory mediator release, resulting in o96 .0:00 -58the beneficial stimulation of inflammatory processes. For example, eosinophils can be recruited to combat parasitic infections.

In addition to primates, such as humans, a variety of other mammals can be treated according to the method of the present invention. For instance, mammals including, but not limited to, cows, sheep, goats, horses, dogs, cats, guinea pigs, rats or other bovine, ovine, equine, canine, feline, rodent or murine species can be treated. However, the method can also be practiced in other species, such as avian species chickens).

Diseases and conditions associated with inflammation and infection can be treated using the method. In a preferred embodiment, the disease or condition is one in which the actions of eosinophils and/or lymphocytes are to be inhibited or promoted, in order to modulate the inflammatory response.

Diseases or conditions of humans or other species which can be treated with inhibitors of CKR-3 receptor function, include, but are not limited to: Sinflammatory or allergic diseases and conditions, including respiratory allergic diseases such as asthma, allergic rhinitis, hypersensitivity lung diseases, hypersensitivity pneumonitis, eosinophilic pneumonias 25 Loeffler's syndrome, chronic eosinophilic pneumonia), interstitial lung diseases (ILD) idiopathic pulmonary fibrosis, or ILD associated with S: rheumatoid arthritis, systemic lupus erythematosus ankylosing spondylitis, systemic sclerosis, Sjogren's syndrome, polymyositis or dermatomyositis); systemic anaphylaxis or hypersensitivity responses, drug allergies to penicillin, cephalosporins), insect sting allergies; inflammatory bowel diseases, such as Crohn's 4 -59disease and ulcerative colitis; spondyloarthropathies; scleroderma; psoriasis and inflammatory dermatoses such as dermatitis, eczema, atopic dermatitis, allergic contact dermatitis, urticaria; vasculitis necrotizing, cutaneous, and hypersensitivity vasculitis); eosinphilic myositis, eosinophilic fasciitis; autoimmune diseases, such as rheumatoid arthritis, psoriatic arthritis, multiple sclerosis, systemic lupus erythematosus, myasthenia gravis, juvenile onset diabetes, glomerulonephritis, autoimmune thyroiditis, Behcet's disease; graft rejection in transplantation), including allograft rejection or graft-versus-host disease; cancers with leukocyte infiltration of the skin or .organs; other diseases or conditions in which undesirable inflammatory responses are to be inhibited can be treated, including, but not limited to, reperfusion injury, atherosclerosis, certain hematologic malignancies, cytokine-induced toxicity septic shock, endotoxic shock), polymyositis, dermatomyositis.

Diseases or conditions of humans or other species .which can be treated with promoters of CKR-3 receptor function, include, but are not limited to: 25 immunosuppression, such as that in individuals with S immunodeficiency syndromes such as AIDS, individuals undergoing radiation therapy, chemotherapy, therapy for autoimmune disease or other drug therapy *o corticosteroid therapy), which causes immunosuppression; immunosuppression due congenital deficiency in receptor function or other causes; infectious diseases, such as parasitic diseases, including, but not limited to helminth infections, such as nematodes (round worms); (Trichuriasis, Enterobiasis, Ascariasis, Hookworm, Strongyloidiasis, Trichinosis, filariasis); trematodes (fluxes)(Schistosomiasis, Clonorchiasis), cestodes (tape worms)(Echinococcosis, Taeniasis saginata, Cysticercosis); visceral worms, visceral larva migrans Toxocara), eosinophilic gastroenteritis Anisaki spp., Phocanema ssp.), cutaneous larva migrans (Ancylostoma braziliense, Ancylostoma caninum).

Eosinophils as the Target Cell in Certain Inflammatory Reactions, Particularly Asthma Eosinophils are produced in the bone marrow and circulate to the tissues, predominantly to mucosal tissues, such as the lungs, gastrointestinal tract, and genitourinary tract. Eosinophils typically constitute 1-3% of leukocytes in the blood. However, in people suffering from allergic diseases and helminthic parasitic infections, increased eosinophil accumulation occurs in the tissues or the blood. Eosinophils accumulation can be both beneficial and detrimental to the host.

For example, eosinophils possess numerous granules, S containing cationic proteins. Degranulation of eosinophils, triggered, for example, by the engagement of IgG, IgA, or IgE receptors, or by stimulation by inflammatory mediators such as platelet-activating factor (PAF), leukotrienes, or chemokines, leads to release of the components in the granule. Products from eosinophils also cause damage to host cells. The most damaging are the cationic proteins, -61which are detectable in elevated concentrations in patients with asthma. Eosinophils also generate a number of inflammatory mediators, including Leukotriene C4, and platelet-activating factor (PAF). These mediators contract airway smooth muscle, promote the secretion of mucus, alter vascular permeability, and elicit further eosinophil and neutrophil infiltration.

Eosinophils are involved in the initiation and maintenance of allergic/asthma diathesis. Thus, in a preferred embodiment, the method can be used to treat asthma or hypersensitivity (allergic) states, particularly those involving mucosal tissues, as well as in other eosinophil-associated diseases. In a particularly preferred embodiment, a compound which inhibits one or more function of a mammalian CKR-3 receptor a human CKR-3 receptor) is administered to an individual with asthma.

Eosinophils are clearly important in the host defense against and destruction of, large, nonphagocytable organisms, such as multicellular helminthic parasites.

Eosinophils are also important effector cells in immune reactions against other pathogens that induce high levels of IgE antibodies. Accordingly, the method can be used to treat infectious diseases, such as parasitic diseases, to stimulate or promote inflammatory defenses, or to suppress inflammatory responses which are destructive to the host.

Eosinophils and Asthma Pathogenesis Asthma is characterized by the obstruction of the airways or bronchi, and results from a bronchial hyperresponsiveness and rapid constriction in response to a wide range of pharmacological mediators. Chronic inflammation of the bronchial mucosal lining is widely believed to play a fundamental role in the development of asthma.

*ge -62- Intense infiltration of the bronchial mucosa with eosinophils, macrophages and lymphocytes is observed in asthma and other hypersensitivities. Often the selective migration of eosinophils to inflamed airways can be striking, and appears to result from the selective binding of eosinophils to endothelium and extraction from the blood. Eosinophils in particular are implicated as the causative agents of bronchial mucosal injury. Studies of asthmatic patients suggest that blood eosinophil counts correlate with the degree of bronchial hyperresponsiveness.

In addition, bronchial biopsies and bronchoalveolar lavage fluid from asthmatics show a clear relationship between the degree of eosinophilia and clinical severity. Thus, there is a strong connection between the presence of eosinophils and adverse immune reactions, particularly in asthma.

A major chemokine receptor on eosinophils and lymphocytes, that functions in selective leukocyte chemotaxis, extravasation and activation in response to chemoattractant, provides an excellent target for interfering with eosinophil recruitment. For example, administration of an inhibitor of at least one function of a mammalian human) CKR-3 receptor, such as by inhibiting chemokine binding thereto, can provide an effective and selective way of treating asthma. By reducing or preventing recruitment (extravasation, infiltration) of leukocytes, particularly eosinophils, to inflamed lung and airway tissues, and/or reducing leukocyte function in those tissues, the destructive inflammatory processes of asthma can be inhibited, and the symptoms 30 alleviated.

There is evidence that the blockage of eosinophil recruitment to the lung can alleviate the symptoms of asthma. Administration of a monoclonal antibody reactive with a4 integrin was reported to inhibit the accumulation 35 of eosinophils into the lung and airways, and blocked the o o -63airway hyperresponsiveness to antigen challenge in sheep.

In a primate model of asthma, a monoclonal antibody to ICAM-1 is reported to attenuate airway eosinophilia and hyperresponsiveness. In addition, in a guinea pig model for passive cutaneous anaphylaxis, In vitro pretreatment of eosinophils with the anti-a4 monoclonal was reported to suppress eosinophil accumulation. (see Wegner, C.D. et al., Science, 247: 456 (1990); Weg, V.B. et al., J. Exp.

Med., 177: 561 (1993); and Abraham, W.M. et al., J. Clin.

Invest., 93: 776 (1994) regarding these models).

Modes of Administration According to the method, one or more compounds can be administered to the host by an appropriate route, either alone or in combination with another drug. An effective amount of a compound a receptor peptide which inhibits ligand binding, an antibody or antibody fragment) is administered. An effective amount is an amount sufficient to achieve the desired therapeutic effect, under the conditions of administration, such as an amount sufficient for inhibition or promotion of a CKR-3 receptor function, and thereby, inhibition or promotion, respectively, of an inflammatory response.

A variety of routes of administration are possible including, but not necessarily limited to oral, dietary, 25 topical, parenteral intravenous, intraarterial, intramuscular, subcutaneous injection), inhalation S intrabronchial, intranasal or oral inhalation, intranasal Sdrops), routes of administration, depending on the disease or condition to be treated. For respiratory allergic diseases such as asthma, inhalation is a preferred mode of administration.

Formulation of a compound to be administered will vary according to the route of administration selected solution, emulsion, capsule). An appropriate composition o *o *oo *o -64comprising the compound to be administered can be prepared in a physiologically acceptable vehicle or carrier. For solutions or emulsions, suitable carriers include, for example, aqueous or alcoholic/aqueous solutions, emulsions or suspensions, including saline and buffered media.

Parenteral vehicles can include sodium chloride solution, Ringer's dextrose, dextrose and sodium chloride, lactated Ringer's or fixed oils. Intravenous vehicles can include various additives, preservatives, or fluid, nutrient or electrolyte replenishers (See, generally, Remington's Pharmaceutical Science, 16th Edition, Mack, Ed. 1980). For inhalation, the compound can be solubilized and loaded into a suitable dispenser for administration an atomizer, nebulizer or pressurized aerosol dispenser).

EXEMPLIFICATION

The present invention will now be illustrated by the following Examples, which are not intended to be limiting in any way.

EXAMPLE 1 Chemotactic Properties of Human Eosinophils and an Eosinophilic-Like Cell Line Chemotaxis of Human Eosinophils To identify antagonists of eosinophilic chemokine receptor(s), it is necessary to identify the important chemokines for eosinophil chemotaxis, and determine the receptor(s) that these chemokines'are binding to.

Chemotaxis experiments were performed in a sensitive and improved chemotaxis assay, which employs an endothelial cell line grown on the polycarbonate membrane of the 30 chemotaxis well.

o** Isolation of Eosinophils 100 ml of heparinized blood was diluted 1:1 with PBS.

ml aliquots were layered over 65%, 75% Percoll step gradients. The gradients were centrifuged at 1500 rpm, min at room temp. The eosinophil/neutrophil layers were transferred to a new tube and erythrocytes lysed by addition of 20 mls 0.2% NaCl for 1 min followed by the addition of 30 mis 1.8% NaCl. Cells were washed twice with a buffer consisting of PBS, 0.5% BSA, 0.5 mM EDTA. Cells were resuspended at 5 x 10' cells/50 p1 in cold buffer (PBS, 0.5% BSA, 0.5 mM EDTA) and 50 p1 CD16 microbeads were added to the cells. The mixture was incubated at 40C for min followed by the addition of 900 1l cold buffer. The miniMACS separation unit (Miltenyi Biotec, Inc., Auburn CA 95603) was used to deplete CD16 positive cells (neutrophils). Cells were loaded onto the column in 200 p1 aliquots. Flow-through cells were collected and assessed histologically. The eosinophil prep was 99% pure.

Chemotaxis Assay Chemokines were obtained from Peprotech, Inc. (Rocky Hill, Chemotaxis experiments were performed using micron Biocoat cell culture inserts (Collaborative Biomedical Products), in 24 well plates. Endothelial cells were grown to confluency on the inserts for two days prior 25 to chemotaxis experiments. The endothelial cells used were a cell line termed ECV 304 (European Collection of Animal Cell Cultures, Porton Down, Salisbury, which expresses endothelial cell markers such as von Willebrand factor, as well as ICAM-1 and VCAM-1. This endothelial cell line greatly facilitates these assays, since human umbilical vein endothelial cells can be variable in nature, can be used for only several passages, and grow much more slowly than ECV 304. The assay was conducted at 37 0 C for o.

-66hours, and migrated cells were counted using an inverted microscope.

Results The results, presented in Figure 4, are representative of at least five experiments. Growth of ECV 304 endothelial cells on the polycarbonate membrane reduced the background migration almost completely. Eosinophils applied to transendothelial chemotaxis assays showed migration to a number of chemokines, particularly

RANTES,

MCP-3, and to a lesser degree MCP-1. MIP-1l, IL-8, MCP-2, and IP-10 had little effect on eosinophil chemotaxis.

MIP-la was chemotactic for eosinophils in some experiments, although generally was inactive. In these experiments, a range of chemokine concentrations was used, because of the variability in responsiveness of leukocytes to different chemokines, and uncertainties about the quality of chemokine preparations. A consistent finding was the high level of eosinophil chemotaxis to RANTES and MCP-3.

Induction of RANTES Chemotaxis in Butyrate Differentiated HL-60 Cells Eosinophils are difficult to isolate in sufficient quantities from human blood to be used for many studies, particularly high-throughput screening. Eosinophilic-like cell lines can provide a substitute for eosinophils. Some 25 laboratories have found that HL-60 cells can differentiate down an eosinophilic pathway (Tagari, P. et ai., Int. Arch.

Allergy Immunol., 101: 227-233 (1993); Van Riper, G. et al., J. Immunol., 152:. 4055-4061 (1994)). HL-60 cells were tested to determine whether such cells could emulate S 30 the chemotactic properties of eosinophils.

HL-60 cells were resuspended in RPMI (without HEPES) fetal calf serum (FCS) at 0.5 x 106 cells/ml.

-67n-Butyric acid (Sigma Chemical Co., St. Louis, MO; #B5887) was added to a final concentration of 0.4 mM from a stock solution of 1 M n-butyric acid. HL-60 cells were incubated at 37 5% CO 2 for four days. The eosinophilic-like nature of these HL-60 cells is indicated by the induction of RANTES and MCP-3 responsiveness in chemotaxis assays (Figures SA-SB). Moreover ligand binding studies as well as northern blot analysis of chemokine receptor expression (see below) confirmed that chemokine receptors were induced on these differentiated HL-60 cells that are similar to those on eosinophils.

EXAMPLE 2 Identification of a Major Eosinophilic Chemokine Receptor Primer Selection and Design Five chemokine receptor genes were aligned and compared to generate a set of degenerate oligonucleotides for use in PCR (Polymerase Chain Reaction) cloning of novel chemokine receptors from eosinophils. The selection of these five receptor genes was based on either the type of chemokine ligand with which they bind (11-8 receptor

A

(IL8RA), Il-8 receptor B (IL8RB),

MIP-

la receptor (MIPlaR)) or orphan receptors with significant sequence similarity to these receptors whose expression is reported to be 25 restricted to lymphoid cells or tissue (Epstein Barr Inducible receptor-1 (EBIIR) and Burkitt's Lymphoma Receptor-i (BLR1)). Receptor sequences were aligned by hand based on a number of published alignments (IL-8RA, Holmes et al., Science, 253: 1278-1280 (1991); IL-8RB, 30 Murphy, P.A. et al., Science, 253: 1280-1283 (1991); MIPla/RANTES, Neote, K. et al., Cell, 72: 415-425 (1991); EBIIR, Birkenbach, M. et al., J. Virol., 67: 2209-2220 .54.

-68- (1993) and BLRI '(Dobner*, T. et al., Bur. J. Immunal 22: 2795-2799 (1992)).

sequences within transmembrane (TM) regions 2, 6 and 7 as well as a region just C-terminal to TM3 were selected as targets for-degenerate oligonucleotide design'based on the high degree of sequence similarity. The nucleotide *Sequences of the degenerate oligonucleotide primers are illustrated in the Table below.' 0 *0 0 i

TABLE

P rimer Set 2 S EO I D NO: TM2a Primer 2a-1 (forward) TAC CTG CTS AAC CTG GCC ITG GCI G Nested primer 2a-2 (forward) AC CTG GCC ITG GCI GAC CT?! CTC TT TM3 9 Primer 3F (forward) Primer 3R (reverse) GAC CGY TAC CTG GCC ATI GTC CAY GCC CTG GCR ATG GAC CGG TAI CAG GTR CGG TM6b Primer 6b-1 (reverse) Nested primer 6b-2 (reverse)- GAR AMR ACC IRI GGG ATG TTR IAC CAI MAG RAI GAR GAR AMIR ACC IRI GGG ATG T TM7 Primer Nested 7-1 (reverse) primer 7-2 (reverse) ACG SAG TTG GGI IAS lAG ATG CGG MAG 51 GTG WCG ACG SAG TTG GGI IAS lAG A 51 Nucleotide Abbreviations:- K =G/T M A/C R A/G S C/G W =A/T Y C/T Eosinophil isolation and Purification 100 ml of heparinated blood was diluted 1:1 with PBS.

ml aliquots were layered over 65%, 75% Percoll step gradients. The gradients were centrifuged at 1500 rpm, min at room temperature. The eosinophil/neutrophil layers were transferred to a new tube and erythrocytes lysed by addition of 20 mis 0.2% NaC1 for 1 minute followed by the addition of 30 mis 1.8% NaC1. Cells were washed twice with a solution of phosphate buffered saline (PBS), 0.5% Bovine Serum Albumin (BSA), 0.5 mM ethylenediaminetetraacetic acid (EDTA). Cells were resuspended at 5 x 107 cells/50 p1 in cold buffer (PBS, BSA, EDTA solution), and 50 p1 CD16 microbeads were added to the cells. The mixture was incubated at 4 0 C for 25 min followed by the addition of 900 pl cold buffer. The miniMACS separation unit (Miltenyi Biotec, Inc., Auburn, CA 95603) was used to deplete CD16 positive cells (neutrophils). Cells were loaded onto the column in 200 p1 aliquots. Flow-through cells Were collected and assessed histologically. By this criteria, the eosinophil prep was 99% pure.

mRNA isolation and PCR mRNA for RT-PCR (Reverse transcription-polymerase chain reaction) was extracted directly from purified cells using the Micro-FastTrack" mRNA isolation kit purchased from Invitrogen. Quality of the mRNA was evaluated by PCR amplification of 3-actin and/or GAPDH (glyceraldehyde-3phosphate dehydrogenase) mRNA prior.to use with 7TMS degenerate primers.

20-50 ng of mRNA was reverse transcribed using a 30 GeneAmp® RNA PCR kit (Perkin-Elmer) with oligo dT and/or random hexamers as primers in a 20 1l final volume as specified by the manufacturer. 2-5 pl of this cDNA (reverse transcribed eosinophil message) was mixed with 200 o o o oooo* o o *oo* o o *o -71- AM dNTPs and 50-100 pmol of degenerate primers in a so ip volume. Magnesium concentration and pH were optimized for each primer pair. The magnesium concentration ranged from to 3.0 mM and pH ranged from 8.5 to 10.0. Although various cycle parameters were also evaluated, the conditions generally used were similar to the following: 3 cycles: 94*C, 30 sec; 37 0 C, 30 sec; 2 min ramp to 72*C, 1 min, followed by 30 cycles: 94*C, 45 sec; 486C, 1 min; 72C, 1 min. (ramp gradual increase).

With regard to the 201 bp fragment isolated (see below), primer pairs 2a-1 and 7-1, or primer pairs 2a-1 and 3R, were used in a PCR reaction (as described above) in mM Tris-HCl, pH 9.5 and 1.5 mM Mgcl 2 One A1 of product from each reaction was used in a separate (second) round of PCR with "nested" primers 2a-2 and 3R. ("Nested" primers are primers which hybridize to sequences within the outside primers.) Reaction conditions for the nested PCR were exactly as described for the first

PCR.

PCR products were assessed and separated by agarose gel electrophoresis, and appropriately sized fragments were purified and subcloned using the pCR-Script SK+ cloning kit (Stratagene). (Appropriate fragment sizes are as follows: for PCR with primer pairs from regions 2a and 7 (see Table above), -700 bp; for PCR with primers from region 2a and primer 3R, -200 bp; for PCR with primer 3F and primers from region 6b, -400 bp, and for PCR with primer 3F and region 7 primers, -550 bp.) Expected fragment sizes were predicted based upon the hypothesis that a related receptor protein would share some structural 30 similarity.

Rapid Screening Assay In order to screen a large number of clones quickly for novel members of the 7TMS family, the inserts of ••co -72bacterial colonies obtained as described above transformants of plasmids comprising appropriately sized fragments subcloned into pCR-Script were screened by PCR using T3 and KS primers complementary to the sequence flanking the polylinker of pCR-Script'. In particular, a portion of a bacterial colony from an overnight transformation was mixed directly with 40 pl of a PCR mixture containing 200 pM dNTPs, 20 mM Tris, pH 8.5, 50 mM KC1, 2.5 mM MgC1 2 50 pmol each primers and 0.25 units Tag polymerase. Cycle conditions were 25 cycles: 940C, 550C, 20 sec; 720C, 30 sec. Inserts of the correct size were identified by evaluating 20 p1 of PCR product on agarose gels. The remaining 20 1l of the reaction was digested with Alu I, Hha I, and Rsa I (triple digestion) and resolved on a 12% polyacrylamide gel to screen for different digestion patterns. Clones of different patterns were then selected for sequence analysis.

Results Sequence analysis of PCR fragment, generated from degenerate oligos, identified a 201 bp partial cDNA clone in pCR-Script. (The degenerate oligos were 2a-1, 2a-2, 3F, 3R and This partial clone, designated Eos L2 (also referred to as L2 and EL2), was found to have 78.3% amino acid similarity (81.1% nucleic acid similarity) to the MIPla/RANTES receptor and 60.8% amino acid similarity (61.6% nucleic acid similarity) to the MCP-1 receptor.

A

search of the most current sequence data bases revealed this partial clone to be unique.

Southern and Northern Analysis The PCR fragment was labeled and used to probe both Southern and Northern blots. To prepare the PCR probe, the 201 bp fragment was released from the pCR-Script vector oo -73with restriction enzymes EcoRI and Not I. This digested resulted in a fragment of 240 bp comprised of the 201 bp fragment plus 39 base pairs of polylinker from the vector.

The fragment was separated from vector by electrophoresis through agarose gel, and purified by (Magic Mini Prep, Promega Corp. Madison, WI) exactly as recommended by the manufacturer. Approximately 200 ng of material was labeled with the Random Primed DNA Labeling Kit purchased from Boehringer Mannheim following the manufacturer's recommended labeling protocol.

For Southern blots, genomic DNA (purchased from Clontech Laboratories, Inc., Palo Alto, CA) was digested with restriction enzyme overnight and separated by electrophoresis on a 0.7% agarose gel followed by capillary transfer to Hybond-N nylon membrane (Amersham).

Hybridization was in 6x SSC (lx SSC is 0.15 M sodium chloride, 0.015 M sodium citrate) containing 5x Denhardt's solution (lx Denhardt's solution is 0.02% bovine serum albumin, 0.02% ficoll, 0.02% polyvinylpyrolidone), 10% w/v dextran sulfate, 2% SDS, and sheared salmon sperm DNA (100 gg/ml) overnight at 650C. The membrane was rinsed twice in 2X SSC, 0.5% SDS at 65 0 C followed by two washes (15 min each) in 0.2X SSC, 0.5% SDS at 650C.

The Southern hybridization revealed a single strongly hybridizing fragment and a single weakly hybridizing fragment with each enzyme used. The weakly hybridizing fragment is likely to be the MIPlal/RANTES receptor.

Multiple Tissue Northern Blots were purchased from Clontech Laboratories, Inc., Palo Alto, CA). ExpressHyb" 30 Solution was also purchased from Clontech Laboratories, Inc. The Multiple Tissue Northern Blots were carried out as recommended by the manufacturer. The probe was as described above for Southern blots. The results of the Northern hybridization showed high levels of a 1.6 kb -74message in spleen, peripheral blood leukocytes and thymus.

Additional Northern analyses are presented in Example Genomic Library Screening A human genomic phage library constructed in the EMBL3 SP6/T7 vector, purchased from CLONTECH Laboratories, Inc.

(Palo Alto, CA), was screened with the 201 bp PCR fragment to obtain a full-length clone. Approximately 25,000 plaque forming units were mixed with 600 Al of an overnight bacterial culture of E. coli strain K802 provided with the library in NZCYM top agarose and plated on 150 mm petri dishes containing NZCYM agar (NZYCM broth, Agar and Agarose were purchased from Gibco/BRL). After incubation at 37oc for 7 hours, the plates were overlaid with nitrocellulose membranes (Schleicher and Schuell, Keene, NH) for 5 minutes to allow transfer of phage to membrane.

The membranes were then soaked for 5 minutes in Denturing Solution (1.5 M sodium chloride, 0.5 N sodium hydroxide) followed by neutralization in 1.5 M sodium chloride, 0.5 M Tris, pH 8.0. The filters were allowed to air dry for minutes and then baked for two hours at 80 0 C under vacuum.

The filters were then hybridized as described above for the Southern Blot. The 201 bp PCR fragment contained the nucleotides between oligonucleotide primers 2a-2 (TM2) and 3R (TM3).

One genomic phage clone, designated Eos L2.8, contained an insert which comprises the 1.8 kb Hind III fragment seen on Southern blots (complete insert size was not determined, but is -17 kb).

Phage clone Eos L2.8 was digested with Hind III 30 restriction enzyme and electrophoresed on an agarose gel.

A Hind III fragment of approximately 1.8 kb was cut out, electroeluted from agarose, phenol/chloroform extracted and precipitated with ethanol. The 1.8 kb fragment was resuspended in water and ligated into the Hind III site of the pBluescript II KS+ vector (Stratagene) followed by transformation into DH5a competent cells purchased from Gibco/BRL.

Both strands of this Hind III fragment were sequenced, and the fragment was found to contain the entire amino acid coding region for the Eos L2 receptor (a human CKR-3 receptor). Comparison of this sequence and the cDNA clone described below indicates that the clone is a fulllength clone. The open reading frame of 1065 nucleotides encodes a protein of 355 amino acids (SEQ ID NO:2) with a predicted molecular mass of 41 Kd.

Comparison of the sequence of the full-length Eos L2 receptor with MIPla/RANTES and MCP-1 receptors revealed a 73.4% and 60.5% amino acid similarity, respectively. For this comparison, sequences were aligned by hand and the number of similar amino acids, divided by the total number of amino acids was multiplied by 100.) The sequences were also aligned by the Clustal method using MegAlignT (DNASTAR, Inc.). Comparison with other chemokine receptor sequences revealed a 62%, 47%, and 41% amino acid sequence similarity to CKR-1, CKR-2B, and CKR-4, respectively. In contrast, the amino acid sequence similarity to IL-8 receptors A and B was only 27% for both receptors. The sequence similarity of this receptor to MIPla/RANTES and MCP-1 receptors, both C-C chemokine receptors, is consistent with the results reported herein which indicate that Eos L2 is a C-C chemokine receptor.

EXAMPLE 3 EExpression of Eos L2 in Transfected Cell Lines FLAG-taqqed Eos L2 (CKR-31 Recentor construct An Eos L2 receptor fusion protein was constructed as follows: S S g tf -76- 1. A FLAG-PAF receptor construct in pCDM8 (constructed as reported in Kunz, D. et al., J. Biol.

Chem., 267: 9101-9106 (1992)) was double digested with Hind III and EcoRI to release a 48 bp fragment containing nucleotides which encode the FLAG peptide. The nucleotide sequence is AAGCTTCCA GCA GCC ATG GAC TAC AAG GAC GAC GAT GAC AAA GAATTC (SEQ ID NO:15). The amino acid sequence is MDYKDDDDKEF (SEQ ID NO:16). The 48 bp Hind III/EcoRI fragment containing the FLAG nucleotides subcloned into the HindIIl/EcoRI sites of the pcDNA3 vector (Invitrogen, San Diego, CA) giving rise to pcDNA3/FLAG.

2. The pBluescript II KS+ vector containing the 1.8 kb Eos L2 Hind III fragment was digested with BamHI and Xho I to release a 1.261 kb fragment. This BamHI-XhoI fragment contains nucleotides encoding Eos L2 amino acids 91 through the stop codon plus the same 3' untranslated region and 21 bp of pBluescript II KS+ vector.

3. Two PCR primers were generated to amplify the 5' end of the Eos L2 gene, but removing the first Met and engineering in an EcoRI site which will be compatible with the EcoRI site described above in step 1. The primer (SEQ ID NO:17) was: EcoRI GAATTC ACA ACC TCA CTA GAT AC This primer contains an EcoRI site and the first 17 nucleotides of the EosL2 gene except for the Met codon.

The 3' primer (SEQ ID NO:18) was: SBamHI 5'-CATAGT GGATCC

AGAATG

This primer primes in the Eos L2 gene just 3' to the BamHI site. Amplification with these two primers using the PBluescript II KS+ vector containing the 1.8 kb Eos L2 fragment as template will amplify a 280 bp fragment 35 containing the 5' end of the Eos L2 which can be digested e *g r- -77with EcoRI and BamHI to give a fragment for ligation as described below.

Conditions for amplification were: 100 ng of pBluescript II KS+ containing the 1.8kb EosL2 fragment was combined with 200 AM dNTPs and 50 pmol of primers in a pl reaction volume. The final magnesium concentration was pM and the pH was 8.0. The fragment was amplified with cycles of 94oC, 30 sec; 550C, 30 sec; 72oC, 30 sec. The amplified product was separated on agarose gel and purified by electroelution as described above. The fragment was digested with EcoRI and BamHI purified again on agarose gel.

4. For construction of the Flag-tagged EosL2 gene, the pcDNA3 vector containing the FLAG fragment (described in step 1) was digested with EcoRI and Xho I.

The vector fragment (an EcoRI-XhoI fragment comprising the FLAG coding sequence) was separated from the polylinker fragment by electrophoresis, and the vector fragment was purified as described for other electroeluted fragments.

The vector fragment was combined with the EcoRI-BamHI fragment generated by PCR in step three. These two fragments were combined with the 1.261 kb BamHI-XhoI fragment from step two. All three fragments were triple ligated together to yield the FLAG-tagged Eos L2 receptor in pcDNA3. Ligated DNA was transformed into Transient Transfectants 293 cells (ATCC Accession No. CRL 1573) were grown in Minimal Essential Medium (MEM) Alpha Medium obtained from Gibco/BRL and supplemented with 10% fetal Calf Serum, Glutamine, and Penicillin/Streptomycin (all from Gibco/BRL) For each transient transfection, 2 x 106 293 cells were plated 1 day before transfection in a tissue culture dish. On the day of transfection, the cells e oo -78- (which grow attached to the dish) were washed 1 x with Phosphate Buffered Saline (PBS, Gibco/BRL) and a mixture of DNA and lipofectAMINE Reagent (Gibco/BRL) were applied to the cells.

The DNA/lipofectAMINE" reagent mixture was made by incubating 2 pg of Flag-tagged Eos L2 receptor expression vector in a final volume of 100 p OptiMEM" (Gibco/BRL) with 12 il of LipofectAMINE7 reagent in a 100 pl volume for minutes at room temp. The final mixture volume is 200 pl. After the 45 minute incubation, 800 p1 of OptiMEM is added to the 200 p1 of DNA/lipofectAMINE" reagent and the 1 ml of solution is layered over the cells as described above. The cells were then incubated at 37 0 C for 5 hours at which time 1 ml of MEM Alpha Medium supplemented as described above is added. The cells are incubated for an additional 12 hours at which time all medium is removed and the cells washed 2 x with PBS and 2 mls of MEM Alpha medium supplemented as described above is added. The transfected cells are then incubated for an additional 72 hours. The cells are harvested by gently pipetting them after incubation in PBS 10 mM EDTA.

Cell surface expression of a FLAG-tagged Eos L2 receptor was demonstrated in the transiently transfected 293 cells. Approximately 2.6% of the cells express the 25 receptor on the surface as determined by immunofluorescent staining and FACS analysis. Levels of expression in some cells were found to be as much as 2 logs greater than background indicating that high levels of expression can be achieved in this cell line. As the Eos L2 gene is carried by the pcDNA3 expression vector (Invitrogen Corp., San Diego, CA), which contains the neomycin resistance gene, stable 293 transfectants can be selected using geneticin (G418) selection.

-79- Stable Cell Lines Over 500 stable lines of mouse L1-2 pre-B cells have been generated with the FLAG-tagged receptor. L1-2 pre-B cells were obtained from (Dr. Eugene Butcher, Stanford University, Stanford, CA), and were maintained in RPMI-1640 (Gibco/BRL), supplemented with 10% bovine serum albumin, and Pen/Strep, sodium pyrvate and S-mercaptoethanol. Cells from over 200 clones were screened for surface expression by staining with M2 anti-FLAG monoclonal antibody (International Biotechnologies, Inc., New Haven, CT), followed by anti-mouse Ig-FITC (Jackson ImmunoResearch Laboratories, Inc.), and analyzed by fluorescence activated cell sorting (FACS). Immunofluorescent staining and FACS analysis was performed as described in Current Protocols in Immunology, Vol. 1, Coligan, J. et al., Eds., (John Wiley Sons, Inc.; New York, NY). Results of the FACS analysis for several cell lines revealed a number of clones which express high levels of the Eos L2 flagged receptor (Figure Untransfected cells (not shown) were negative for staining. Stable cell lines with high level expression can be used as immunogens for the production of antibodies reactive with the Eos L2 receptor. In addition, these cell lines are useful for studying chemotaxis and ligand binding.

25 Baculovirus Expression For construction of a baculovirus expression vector, e*o. the Flag-tagged Eos L2 receptor in pcDNA 3 was digested with HindIII to remove the Flag-tagged gene. The HindIII fragment containing the gene was blunt ended by filling in 30 the overhangs with Klenow fragment and dNTP's. *The blunt ended fragment was subcloned into the Sma I site of pVL1393 (Invitrogen). 2.0 pg of the pVL1393 vector containing the Eos L2 gene was mixed with 0.5 pg of AcMNPV viral DNA (Invitrogen) and co-transfected into Sf9 insect cells (Invitrogen) with Insectin" (Invitrogen) according to the manufacturer's instructions. The SF-900 media (serum free) was replaced with 5 ml of SF-9 culture medium (Grace's Supplemented Insect Media (Gibco/BRL) containing 10% fetal calf serum) on the following day, and the cells were allowed to grow for five days. Recombinant virus was plaque purified as described in D.R. O'Reilly, L.K. Miller, and V.A. Luckow (1994) Baculovirus expression vectors:

A

Laboratory Manual, Oxford University Press, pp. 149-158.

Expression of the Eos L2 receptor was obtained on Sf9 cells by infecting Sf9 cells with the plaque purified recombinant virus described above. The Sf9 cells (2 X 106 cells/ml) were infected at a multiplicity of infection of 10:1. The infection proceeded for 72 hours at which time the cells were stained with the M2 anti-FLAG antibody.

Successful expression of this receptor was also achieved with a baculovirus expression system in Sf9 cells.

Good levels of expression have been achieved based on staining with anti-FLAG antibody (see Example Ligand binding was also achieved with the same cells Sf9 transfectants shown by FACS to be expressing receptor.

While definitive cell surface expression was shown by propidium iodide exclusion, expression on these cells appeared to be low, as compared with a negative control Sf9 cells transfected with expression vector lacking the Eos L2 gene insert). Length of infection can be decreased, and MOI can be further optimized, for higher Scell surface expression.

-81- EXAMPLE 4 Ligand Binding Studies Licrand Binding Procedure Cells transfected with Eos L2 receptors or normal human eosinophils purified (see above) were washed in Hanks Balanced Saline Solution (HBSS), then resuspended in binding buffer: 50 mM HEPES, 1 mM CaCl 2 5 mM MgC1 2 Bovine Serum Albumin (BSA), pH 7.3. In microfuge tubes, x 105 cells were incubated with 0.1 nM radiolabeled chemokine (purchased from New England Nuclear, Massachusetts) in 200 Ml aliquots at room temperature for minutes. The cells were either incubated with radiolabeled chemokine alone, or together with unlabeled chemokines (from PeproTech) as competitors, which were used at the indicated concentrations. At the end of incubation, cells were washed 3 times in the binding buffer, each wash consisting of centrifugation in a microfuge at 7,000 x g for 2 minutes. After the wash, the pellets were transferred into LP3 tubes and the radioactivity of the cells, which represented the amount of binding was measured in a gamma counter. All samples were in duplicates and all the experiments were repeated at least 3 times. Scatchard Plot was calculated from the binding data by MicroSoft Excell and CricketGraph on a Macintosh computer.

25 Binding to Human Eosinophils Based on the findings from chemotaxis assays (see Example the ligand binding studies focused on RANTES, MIP-Io and MCP-3. The ligand binding studies were carried out using radiolabeled chemokines and various 'cold' 30 chemokines as competitors. Purified normal human eosinophils were incubated with either 0.1 nM 1 MIP-la or RANTES in the presence or absence of various cold -82chemokines (250 nM MIP-la, RANTES, IL-8, MCP-1 or MCP-3).

After extensively washing the cells, the binding was measured by a gamma counter.

Figure 7 is a histogram illustrating the binding of human eosinophils to RANTES and MIP-la. These results suggest that eosinophils bind only weakly to MIP-la, and that this binding can be inhibited by MIP-la itself and by other 6-family chemokines, MCP-1, MCP-3 and RANTES (Figure In contrast, eosinophils bound RANTES more abundantly (Figure Binding by RANTES could not be inhibited efficiently by excess amount of 'cold' MIP-la (Figure suggesting that on eosinophils, there could be distinguished receptors for MIP-la and RANTES.

Scatchard plot analysis revealed that there are 1.8 x 103 MIP-la binding sites with an affinity of 91 pM. The analysis also revealed a lower affinity (883 pM) receptor for RANTES, having more binding sites (3.6 x 10 4 /cell).

Under the conditions used, there was no significant MCP-1 binding to eosinophils (not shown), and MCP-1 did not inhibit RANTES binding except at very high concentrations (2500-fold excess, Figure 8).

Binding to Butyric Acid-Differentiated HL-60 Cells Butyric acid-differentiated HL-60 cells were used in the ligand binding assay to determine whether these cell 25 behave in the same way as eosinophils. Assays were performed as described above, using 0.5 X 106 HL-60 cells incubated with 0.1 nM 1 I-labeled MIP-la or RANTES in the absence or presence of 250 nM cold chemokine (MIP-la, RANTES, MCP-3, 11-8, MCP-1). In these cells, both MIP-la 30 and RANTES bound equally well and both could cross-inhibit each other (Figure This observation is consistent with the chemotaxis assays (see Example 1) in which both chemokines induced transendothelial migration of -83eosinophils (Figure It appears that during the induction process, both receptors were unregulated since the binding of MIP-la and RANTES was insignificant in undifferentiated HL-60 cells (data not shown).

Eos L2 Recentor Transfectants Following the cloning and expression of the Eos L2 receptor, transfected cells were used to test binding to a number of chemokines. The first attempts using 293 transfectants were unsuccessful, as the addition of cold chemokines interfered with binding, a phenomenon observed by other investigators. In contrast, using baculovirus infected SF9 cells, good RANTES binding could be detected (Figure 10). The assay conditions for SF9 cells were different from that of mammalian cells. Binding of 0.1 nM 1 2I-labeled RANTES took place in 50 mM HEPES, pH 7.3, .5 mM MgC12 and 1 mM CaC1 2 supplemented with 0.5% BSA. After minutes at room temperature, the cells were washed three times in the binding buffer containing 0.5 M NaCl, and the radioactivity in the cell pellets was counted using a gamma counter.

In these ligand binding assays, the most effective heterologous competitor of MIP-la or RANTES binding was MCP-3. In fact, MCP-3 also effectively inhibited MCP-1 binding to activated T cells. Thus, MCP-3 appears to bind to CKR-1, CKR-2 and CKR-3 (CKR-1, Gao, et al., J.

Exp. Med., 177: 1421-1427 (1993) and Neote, et al., Cell, 72: 415-425 (1993); CKR-2, Charo, et al., Proc.

Natl. Acad. Sci. USA, 91: 2752-2756 (1994) and Myers, S.J., et al., J. Biol. Chem., 270: 5786-5792 (1995)).

30 Radiolabeled MCP-3 (Peprotech, Inc. Rocky Hill, N.J.) was also used for binding studies. Figures 11A-11B are graphs illustrating the binding of MCP-3 to differentiated HL-60 cells. MCP-3 binding was carried out as described -84above with the following modifications. Cells were incubated with 0.1 nM 1 I-labeled MCP-3. The binding buffer used was HBSS plus 0.5% BSA and 0.1% sodium azide.

Binding took place at 370C for 30 min. The unbound isotope was separated by spinning cells through 800 gl of sucrose, at 12,000 x g for 2 min. The tubes were then snap-frozen in dry ice, the tips cut off with a pair of pliers and counted.

EXAMPLE Expression of the Eosinonhilic Chemokine Receptor To confirm that the Eos L2 receptor is the functional receptor on eosinophils, the expression of the receptor was assessed by Northern blot analyses, and flow cytometry using monoclonal antibodies anti-peptide antibodies reactive with the receptor.

Purification of Human Eosinophils. Neutrophils, and PBMC Eosinophils were isolated from heparinized blood of individuals with high levels of circulating blood eosinophils by combined density gradient centrifugation and negative selection with anti-CD16 magnetic beads (Hansel, T.T. et al., J. Immunol. Meth., 122: 97 (1989)). Briefly, the granulocyte fraction from the Percoll centrifugation was incubeated with CD16 microbeads (Miltenyi Biotec, Inc., Sunnyvale, CA) for S: 25 minutes. Cells were then passed through a MACS column .:(Miltenyi Biotec, Inc.), and eosinophils were collected in the flow-through. Eosinophils were shown histologically to be 99% pure as determined by analysis of Diff-Quickstained cytocentrifugation preparations by light 30 microscopy.

Human neutrophils were isolated from heparinized venous blood by Percoll density gradient centrifugation (6 1.088) at room temperature (Coligan et al., Eds., 1992, Current Protocols In Immunology, (John Wiley Sons: New York, RBCs were removed by hypotonic lysis.

PBMCs were also isolated as described (Coligan et al., Eds., 1992, Current Protocols in Immunology, (John Wiley Sons: New York, Monocytes were purified by CD14 positive selection with magnetic beads and T cells were purified by passage of lymphocytes over nylon wool. To generate CD3 blasts, 2 X 106 PBMCs/ml in RPMI-1640 plus FCS were added to tissue culture plates first coated with the anti-CD3 antibody TR77. After 4-6 days blasts were removed to fresh media and supplemented with IL-2 (Genzyme) at 50 units/ml.

Northern Analyses: CKR-3 Is Expressed Selectively in Eosinophils Although eotaxin is a selective chemoattractant for eosinophils, the CKR-3 receptor also binds RANTES and MCP- 3, which are known to attract monocytes and T cells.

Message expression of the receptor was examined in various leukocyte populations.

The results of initial Northern hybridization (see Example 2) showed expression of a 1.6 kb message in 25 spleen, peripheral blood leukocytes, and thymus, and a number of leukocyte subpopulations, such as eosinophils and T cells, as well as in the HL-60 cell line. Message levels increased dramatically in the HL-60 cell line upon butyric acid induction down the eosinophilic pathway.

This message is likely to be that of Eos L2, since the message for the MIPla/RANTES receptor which crosshybridizes on Southern blots is weak and is reported to be approximately 3.0 kb. When the original 201 bp PCR

I.

-86fragment is used as a probe in Southern blots, a strongly hybridizing 1.8 kb HindIII fragment is seen. This is the fragment that was cloned and discussed here. In addition to this fragment, a very weakly hybridizing fragment at about 10 kb is observed. This 10 kb fragment corresponds to the reported HindIII fragment size of the MIPla/RANTES receptor. This MIPla/RANTES receptor produces a message of approximately 3 kb which is not observed on Northerns.

Therefore, the -1.6 kb message seen on Northerns probably derives from Eos L2 gene. By far the most abundant expression of Eos L2 was observed in a preparation of purified eosinophils from a patient with hyper-eosinophilic syndrome (see Example 8).

Because of the high sequence similarity of CKR-3 to other CC chemokine receptors and the fact that the fulllength clone hybridizes to multiple sequences in Southern blots, additional Northern analyses used a 250 bp fragment from the 3 '-untranslated region of the genomic clone which does not cross-hybridize with other sequences in Southern blots. For hybridization, a 3 '-untranslated region probe specific for CKR-3 was used encompassing nucleotides 1203-1453 (Figure 1C).

A Northern blot panel was prepared using RNA from different leukocyte populations, including monocytes, neutrophils, lymphocytes, T cells, T cell blasts produced by activation with CD3 MAb, and eosinophils. RNA was isolated using TriZOL T reagent (Gibco/BRL) following the manufacturer's recommended protocol. 15 pg of total

RNA

isolated from each highly purified leukocyte population was 30 separated on 1.2% formaldehyde agarose gels and transferred to Nytran-PlusTM nylon membrane (Schleicher and Schuell) Sand cross-linked using a Stratalinker®. Hybridization with radiolabeled 3'-untranslated region probe was with ExpressHybTM Solution (Clontech) using the manufacterer's -87suggested protocol. Northern blots were exposed to X-OMAT AR film for 3-5 days with intensifying screen. CKR-3 specific probe was removed by boiling in 0.5% SDS and the blot re-probed with a-actin to control for variation in loading.

The only cell population which gave a detectable signal was eosinophils, where a message 1.8 kb in size was found. These results are consistent with the pattern of surface expression detected immuniogically in Figures 13A- 13D. Although message was not detected in resting or activated T cells in this experiment, it is possible that a subset of T cells may express the receptor.

onoclonal Antibodies MAbs) Reactive with the Eosinohilic Chemokine Receptor MAbs reactive with the Eos L2 receptor were generated by immunizing mice with a synthetic peptide corresponding to the N-terminal 35 amino acids. The N-terminal 35 amino acids of Eos L2, deduced from the nucleotide sequence (see Figures 1A-1C; see also, SEQ ID NO:2), were synthesized and coupled to the carrier protein PPD (Purified Protein Derivative of Mycobacterium tuberculosis; Severn Biotech Ltd., Cambridge, Female Balb/C mice were immunized with 50 Ag of this peptide peptide-carrier conjugate in PBS 4 times at 2 week intervals. Mice were injected intra-peritoneally with the S..peptide conjugate, using Freund's complete (first injection) and incomplete adjuvant (subsequent injections).

The final immunization was injected intravenously without adjuvant. Polyclonal antiserum was also collected from mice immunized with synthetic peptide.

Two successful fusions were performed which generated over 15,000 hybridomas. Four days after the final injection, the spleen was removed and a single cell suspension prepared in serum free DMEM media. These cells -88were fused with the hybridoma fusion partner according to Galfre, G. et al. (Galfre, G. et al., Nature, 266: 550-552 (1977)). 20 ml of spleen cells and 20 ml of were combined, spun at 800g for 5 min and the media removed. A solution of 50% Polyethylene glycol 1500 (Boehringer Mannheim, Indianapolis, IN) prewarmed to 37 0

C

was added to the cell pellet over 2 min, followed by 10 ml of DMEM media over 3 min. The cell suspension was spun at 400g for 3 min and the supernatant removed. The pellet was resuspended gently in DMEM media containing 20% fetal calf serum, 2 mM L-glutamine, 100 units/ml penicillin, 100 Ag/ml streptomycin sulfate, and HAT selection media (Boehringer Mannheim, Indianapolis, IN). Cells were plated into 96 well flat bottom microtiter plates at 200 pl/well.

10-14 days later, supernatants from the wells were screened for reactivity against the peptide using an enzyme-labeled anti-mouse antibody (Horseradish peroxidaselabeled anti-mouse IgG (Jackson) in an ELISA assay.

Approximately 200 mAbs were selected that showed strong reactivity against the synthetic peptide. Hybridomas of interest were subcloned using limiting dilution.

To determine which antibodies could recognize the native, surface expressed molecule, the MAbs were screened against Sf9 insect cells infected with AcMNPV virus carrying human Eos L2 genomic DNA. These insect cells expressed Eos L2 (CKR-3) receptor on the cell surface, as judged by strong anti-FLAG staining of approximately 10% of cells. Staining was performed using M2 anti-FLAG antibody, followed by anti-mouse Ig-FITC (Jackson ImmunoResearch 30 Laboratories, Inc.), and analyzed by flourescence activated cell sorting, using FACScan analysis to quantitate expression. (Current Protocols in Immunology, Vol. i, Coligan, J. et al., Eds., (John Wiley Sons, Inc.; New York,

NY).

-89- Approximately 33% of the anti-peptide hybridomas reacted with the Eos L2 transfected insect cells, with a staining pattern identical to that of the FLAG antibody, as determined by FACS analysis using anti-mouse Ig-FITC (Jackson ImmunoResearch Laboratories, Inc.) as second antibody. Untransfected insect cells stained with anli- FLAG were completely negative. Anti-peptide antibody also tested against untransfected cells, which were negative for staining.

MAbs that were found to stain the transfected insect cells were examined using FACS analysis for their reactivity with human eosinophils, peripheral blood lymphocytes, monocytes, neutrophils, and activated T cells (activated T cells; lymphocytes were treated with an anti- CD3 antibody to activate T cells). Cells were stained with mAb LS26-5H12 and then FITC-anti-mouse Ig (Jackson ImmunoResearch Laboratories, Inc.). Fc receptor binding was controlled for by using an excess of normal human serum.

All eosinophils were stained with a selected anti-Eos L2 mAb, LS26-5H12 (Figure 12A). Monocytes were weakly positive for immunofluorescence. A small proportion of lymphocytes were positive for staining (Figure 12B), and substantially all of the activated T cells were weakly stained with the antibody LS26-5H12 (not shown), suggesting that T cells express receptor which is upregulated upon T cell activation. Neutrophils were not significantly *'stained by LS26-5H12 antibody under the conditions of the assay. Based on the expected distribution of the Eos L2 receptor, and that it functions in RANTES binding, MAb LS26-5H12 appears to recognize the naturally expressed form of this receptor. In addition to the LS26-5H12 MAb, five additional Mabs behaved similarly.

The LS26-5H12 hybridoma was further purified by 35 limiting dilution. In another experiment, highly purified &se leukocyte subsets (purified as described in Example 5) were stained with MAb LS26-5H12 and analyzed by flow cytometry (Figures 13A-13D). Staining profiles were representative of at least 4 experiments. T Cells were identified based on CD3 staining. Monocytes and neutrophils were identified by forward and side scatter.

Highly purified eosinophils stained strongly with LS26-5H12 (Figure 13A), suggesting abundant expression of the receptor on the surface of eosinophils, and consistent with a high receptor number determined by ligand binding and Scatchard analysis. Neutrophils, blood T cells, and monocytes showed little or no staining with this MAb (Figures 13B-13D). These latter results, using antibody from the recloned hybridoma, suggest CKR-3 is selectively expressed on eosinophils, and is not appreciably expressed on other leukocyte types tested. However, it is possible that a subset of T cells expresses the receptor.

Antibody Inhibition of Chemotaxis Polyclonal antiserum (collected from the same mouse from which the LS26-5H12 MAb was made) were used in a chemotaxis assay, using butyric acid-differentiated cells as described above, and culture inserts. (The insert forms an upper chamber when placed into a well of the microtiter dish). Chemotaxis of the butyric aciddifferentiated HL-60 cells in response to 100 ng/ml of RANTES (in the lower chamber) was monitored. Chemotaxis in response to RANTES occurred to the same extent in a no S serum control as in the presence of 1 pl of normal mouse serum (placed in the upper chamber with cells). In 30 contrast, in the presence of 1.0 g1 of antiserum (placed in the upper chamber with cells), RANTES-induced chemotaxis was inhibited by 40%. In a different test, using a polyclonal anti-peptide rabbit serum did not similarly inhibit chemotaxis.

*oooo o *g *oo *o *o o -91- EXAMPLE 6 Selection of Stable LI.2 Cell Transfectants 5% of transiently transfected COS, HEK-293 and CHO cells were surface positive as assessed using antibodies to FLAG-tagged receptor (see above), while substantial intracellular protein could be detected, suggesting inefficient protein trafficking. The L1.2 mouse pre-B cell line was used to select lines with higher levels of surface expression (see Figure 6) for further assessment of ligand binding specificity and signal transduction by CKR-3. This cell line has been used successfully for the study of other chemoattractant receptors (Honda, et al., J. Immunol., 152: 4026-4035 (1994)), and the expression of transfected human chemokine receptors confers specific chemotactic ability to various ligands (see below).

To monitor surface expression of CKR-3, a monoclonal antibody (MAb) was produced to the N-terminal region of the receptor, by immunizing mice with a synthetic peptide having a sequence corresponding to the N-terminal 35 amino acids of CKR-3. Anti-peptide MAbs were detected by ELISA, and MAbs that recognize the native receptor were identified by their reactivity with human eosinophils, as well as their staining of transient transfectants.

Construction of CKR-3/pcDNA3 PCR was used to modify the CKR-3 gene contained in the 1.8 kb genomic fragment by inserting a HindIII restriction S site and optimal Kozak sequence immediately 5' to the initiation codon. The coding region and 448 bp of 3'-untranslated region were inserted into the HindIII site of pcDNA3 (Invitrogen), placing the gene under the control of the human CMV immediate early gene promoter of the vector. The details of the construction of this FLAGoo*° -92tagged Eos L2 (CKR-3) receptor construct (also referred to herein as CKR-3/pcDNA3) are provided in Example 3.

Transfection and Stable Cell Line Selection The murine pre-B lymphoma cell line LI.2 was obtained from Dr. Eugene Butcher (Stanford University) and maintained in RPMI-1640 supplemented with 10% bovine serum.

Ag of linearized, CKR-3/pcDNA3 was used to transfect the cell line as follows. L1.2 cells were washed twice in HBSS and resuspended in 0.8 ml of the same. The plasmid DNA was mixed with the cells and incubated for 10 minutes at room temperature then transferred to a 0.4 cm electroporation cuvette and a single pulse applied at 250 V, 960 pF. The electroporation was followed by a 10 minute incubation at room temperature. G418 was added to a final concentration of 0.8 mg/ml 48 hr post-transfection and the cells plated in 96 well plates at 25,000 cells/well. After 2-3 weeks under drug selection, G418 resistant cells were stained with 5H12 anti-receptor mAb (see below) and analyzed by FACScan®.

Lines with detectable surface staining were expanded and cloned several times by limiting dilution. Clones with the brightest surface staining were further analyzed by Northern hybridization to confirm the presence of transfected receptor as well as by RT-PCR using a T7 primer .25 complementary to the pcDNA3 vector as the 5' primer-and a CKR-3 specific primer as the 3' primer (not shown).- No amplification was seen without addition of reverse transcriptase.

For transient transfection, 20 gg of supercoiled

DNA

was used in the electroporation exactly as described for stable cell line production. Cell surface staining was assessed after 48-72 hrs.

-93- L1.2 cells transfected with CKR-3/pcDNA3 were diluted to 1 X 106 cells/ml in tissue culture media. n-butyric acid (sodium salt, Sigma Chemical Corp., Cat. No. B5887) was added to a final concentration of 5 mM (diluted from a 1M stock solution made in tissue culture media). Cells were grown overnight (18-24 hours) at 37oC, 5% CO 2 prior to use. Lower concentrations have been used successfully 2.5 mM and 1 mM n-butyric acid). n-butyrate treatment has been reported to induce protein levels up to about 10-fold relative to uninduced controls (see, e.g., Palermo, et al., J. Biotech., 19: 35-48 (1991) and references cited therein). CKR-3 mRNA levels driven by the human CMV immediate early gene promoter were elevated dramatically by n-butyrate treatment.

Monoclonal Antibody Production and Flow Cvtometry MAbs reactive with synthetic peptide were produced as described above in Example 5. MAbs were screened by ELISA as follows. 50 gl of peptide, at a concentration of 2 Jg/ml in carbonate buffer, was used to coat NUNC 96-well Maxisorp plates for at least 4 hours at 40C. 300 Ml/well of blocking buffer (PBS 1% BSA) was added for at least 2 hours. Plates were washed four times with PBS/Tween and 50 Ml of MAb supernatant was added to each well and incubated at 37 0 C for one hour. Plates were washed four times with PBS/Tween 20 and alkaline phospatase-conjugated Ssecond antibody (Jackson ImmunoResearch Laboratories, West Grove PA) diluted 1:500 in PBS was added to each well.

After an incubation at 37 0 C for 30 minutes, plates were S: washed four times with PBS/Tween 20. The substrate used 30 for the color reaction was p-nitrophenylphosphate dissolved in diethanolamine buffer (Bio-Rad). Plates were read at 410 nm on an ELISA reader.

go *eoeo *eee• oooo *o•O• oo *ooeo -94- To determine which anti-peptide MAbs could recognize native, surface expressed CKR-3, the anti-peptide MAbs were screened against transiently transfected cells and eosinophils. For MAb staining, cells were washed once with PBS, and resuspended in 100 il PBS containing 2% FCS, 0.1% sodium azide (FACS buffer), 5 pg/ml purified antibody, Pg/ml MOPC-21 IgGI isotype matched control MAb (Sigma) or 100 Al hybridoma culture supernatant. After 30 min at 4"C, cells were washed twice in FACS buffer, and resuspended in 100 pl of FITC-conjugated affinity purified F(ab') 2 goat anti-mouse IgG (Jackson). After incubating for 30 minutes at 40C, cells were washed twice in FACS buffer and analyzed by FACScan* to determine the level of surface expression.

Propidium iodide was used to exclude dead cells.

Surface Expression of Receptor on Stable Transfectants of the L1.2 Cell Line Figure 14A shows detectable surface staining of the transiently transfected receptor on a subpopulation of L1.2 cells, using an anti-receptor MAb, LS26-5H12.

Untransfected L1.2 cells were negative (Figure 14B). A stable cell line was constructed by limiting dilution cloning of the transfectants and selection for higher surface staining as described above. This process yielded lines that had much higher levels of receptor expression 25 (Figure 14C). Northern blot analysis confirmed the presence of transfected CKR-3 mRNA in one of the subclones, designated E5, and its absence in untransfected L1.2 cells (not shown).

*oO* *oooo o *o *o* ooo* ooo EXAMPLE 7 Ligand Bindina Specificity of Stable L.2 Transfectants Chemokines Recombinant human chemokines were obtained from Peprotech, Inc. (Rocky Hill, NJ), except for human eotaxin which was synthesized using solid-phase methods that were optimized and adapted to a fully automated peptide synthesizer (model 430A; Applied Biosystems, Inc., Foster City, CA) as described (Clark-Lewis, et al., Biochemistry, 30: 3128-3135 (1991)). Human eotaxin is also commercially available from Peprotech.

12 I-labeled eotaxin was produced using the Bolton Hunter reagent (NEN), as described (Coligan, et al., Eds., 1992, Current Protocols in Immunology (New York: John Wiley and Sons)). The specific activity of radiolabeled eotaxin was calculated to be 180 Ci/mM.

Ligand Binding Chemokine binding to target cells was carried out using a modification of a previously reported method (Van Riper, et al., J. Exp. Med. 177: 851-856 (1993)).

Cells were washed once in PBS and resuspended in binding buffer (50 mM HEPES, pH 7.5, 1 mM CaCl2, 5 mM MgCl,, BSA and 0.05% azide) at a concentration of 1 x 10 7 /ml.

25 Aliquots of 50 gl (5 x 105 cells) were dispensed into microfuge tubes, followed by the addition of cold competitor and radiolabeled chemokines. The final reaction volume was 200 il. Non-specific binding was determined by incubating cells with radiolabeled chemokines in the 30 presence of 250-500 nM of unlabeled chemokines. After minutes incubation at room temperature, the cells were go* o e o* -96washed 3 times with 1 ml of binding buffer containing 0.5 M NaCl. Cell pellets were then counted.

Competition is presented as the percentage of specific binding as calculated by where S is the radioactivity of the sample, B as background binding and T as total binding without competitors. Background binding was obtained by incubating cells with radiolabeled chemokine and at least 400-fold excess of unlabeled chemokines. The total binding of eotaxin to E5 cells was 11611 119 cpm and background binding 2248 745 cpm. The total binding of eotaxin to eosinophils was 7866 ±-353 cpm and background binding 1148 518 cpm. Duplicates were used throughout the experiments and the standard deviations were always less than 10% of the mean. All experiments were repeated at least three times. Curve fit was calculated by KaleidaGraph software.

The E5 cell line described in Example 6 was tested for its ability to bind radiolabeled eotaxin. Cells were incubated with 0.6 nM '"I-labeled eotaxin and various concentrations of cold competitor. Figure 15A shows that the transfected cells bound '"I-labeled eotaxin specifically and with high affinity. Scatchard analysis of the binding data indicated a dissociation constant (Kd) of nM (Figure 15C), similar to the value of 0.5 nM obtained using purified human eosinophils (Figure 15D). In addition, both RANTES and MCP-3 were able to specifically :compete for binding. None of the other chemokines tested, including MIP-la, MIP-10, or IL-8 were able to specifically compete for radiolabeled ligand (Figure 16).

Chemotaxis Assays Chemotaxis with human eosinophils was assessed using a modification of a transendothelial assay (Carr, M.W. et al., Proc. Natl. Acad. Sci. USA, 91: 3652-3656 (1994)).

eeoc -97- The endothelial cells used for this assay were the endothelial cell line ECV 304, obtained from the European Collection of Animal Cell Cultures (Porton Down, Endothelial cells were cultured on 6.5-mm diameter Biocoate Transwell tissue culture inserts (Costar Corp., Cambridge MA) with a 3.0 MM pore size. Culture media for ECV 304 cells consisted of M199 10% Fetal Calf Serum, L-glutamine, and antibiotics.

Assay media consisted of equal parts RPMI 1640 and M199, with 0.5% BSA. 24 hours before the assay, 2 X 10 ECV 304 cells were plated onto each insert of the 24-well chemotaxis plate, and incubated at 37 OC. Chemotactic factors (diluted in assay medium) were added to the 24-well tissue culture plates in a final volume of 600 pl.

Endothelial-coated tissue culture inserts were inserted into each well and 106 cells were added to the top chamber in a final volume of 100 pl. The plate was incubated at 37 0 C in 5% C0 2 /95% air for 4 hours.

The cells that had migrated to the bottom chamber were counted using flow cytometry. 500 pl of the cell suspension from the lower chamber was placed in a tube, and relative cell counts were obtained by acquiring events for a set time period of 30 seconds. This counting method was found to be reproducible, and enables gating on the leukocytes and the exclusion of debris or other cells.

Counts obtained in this way match closely those obtained by counting with a microsope.

The same assay was used to assess chemotaxis of L1.2 cells or L1.2 receptor transfectant cell lines, except that endothelial cells were not used to coat the Biocoate Transwell tissue culture inserts.

-98- CQR-3 expression in l. 2 cells confers chemotactic responsiveness for eotaxin. RANTES and Mcp-3 L1.2 receptor transfectants were tested for their ability to migrate in response to a panel of chemokines over a range of concentrations. The CKR-3 expressing cell line E5 showed a chemotactic response to eotaxin,

RANTES,

and MCP-3 with a peak response to eotaxin at 100 ng/ml, although specific migration could be detected as low as ng/ml (Figure 17A). While a response to RANTES was evident at both 10 ng/ml and 100 ng/ml, the magnitude of the response was not as great as with eotaxin. MCP-3 appeared to be a less potent chemoattractant on the E5 cell line than on eosinophils, with no detectable migration below 100 ng/ml. No significant response to other chemokines tested was seen with this cell line. In other control experiments, cells did not migrate to the bottom chamber when chemokine was added to the top well alone, confirming that cell migration was chemotactic rather than chemokinetic (not shown).

The untransfected L1.2 cell line did not migrate in response to any chemokines tested (Figure 17B). Indeed, a striking feature of the L1.2 cell line was the very low background chemotaxis to non-specific ligands. As a specificity control, L1.2 cells transfected with IL-8 RB migrated specifically in response to IL-8 and GROa (Figure 17C), as well as NAP-2 and ENA-78 (not shown), but not to other CXC or CC chemokines. Other chemokine receptors which were introduced into L1.2 cells by transfection also confer chemotactic ability to their specific ligands, 0: 30 including CKR-2 transfectants (which respond to MCP-I and MCP-3), CKR-1 transfectants (which respond to MIP-la), and IL-8 RA transfectants (which respond to IL-8) (not shown).

Pertussis toxin completely abrogated the chemotactic response of both eosinophils and the CKR-3 transfectants to eotaxin indicated that the receptor was signaling through o o -99the G subclass (Simon, et al., Science, 252: 802-808 (1991)) in both normal and transfected cells (not shown).

The chemotactic profile of eosinonhils resembles that of CKR-3 transfectants In order to assess whether the function of normal eosinophils resembled that of CKR-3 L1.2 transfectants, chemotaxis experiments were performed using eosinophils from a number of normal individuals (humans), having high levels of eosinophils to 8% of WBC) (purified as described in Example Figures 18A-18B show two characteristic patterns of eosinophil chemotaxis observed in two different individuals. One pattern was characterized by a robust migration to eotaxin, and a lesser response to RANTES and MCP-3 (Figure 18A). The other pattern showed essentially equivalent chemotaxis in response to eotaxin, RANTES and MCP-3 (Figure 18B). These patterns were not due to variations in the assay, since within each individual, they were highly reproducible over a long period of time. MIP-la showed only weak chemotactic activity for eosinophils in the second class of individuals.

EXAMPLE 8 Cloning of a cDNA encoding Eos L2 Construction of an Eosinophil cDNA Library 25 Eosinophils were obtained from a patient diagnosed with idiopathic hyper-eosinophilic syndrome (Costa, J.J. et al., J. Clin. Invest., 91: 2673 (1993).

RNA was isolated using a standard guanidinium isothiocyanate/cesium chloride method (In: Current Protocols In Molecular Biology, Vol. 1, Ausubel, F.M. et al., Eds., (John Wiley Sons: New York, NY) page 4.2.2- 4.2.3 (1991)). mRNA was obtained using.Dynabeads (Dynal, -100- Inc.), and the bacteriophage library was constructed using the SUPERSCRIPT" Lambda System for cDNA Synthesis and X Cloning (Gibco BRL, Life Technologies) which comes with Xgt22A, NotI-SalI arms.

Library Screening We screened approximately 750,000 bacteriophage plaques of the resulting human eosinophil cDNA library in duplicate. The probe used was a full-length radiolabeled cDNA probe (p4 cDNA) which encodes the MIP-la/RANTES receptor (CKR-1)(Gao et al., J. Exp. Med., 177: 1421 (1993)). The p4 cDNA was cloned into the BamHI and XhoI sites of pcDNAI (Invitrogen). A BamHI-XhoI fragment of this clone p4 cDNA in pcDNAI) was obtained by restriction digestion, and isolated using Gene Clean (Bioll0). The fragment was labeled with 32 P using a random primer labeling kit (Boehringer Mannheim Biochemicals).

Filters were prehybridized by incubation for two hours at 42 oC, in a solution of 50% formamide, 5 X SSC, lX Denhardt's, 10% Dextran Sulfate, 20 mM TRIS, pH 7.5, 0.1% SDS (sodium dodecyl sulfate). Hybridization was performed overnight at 42 oC in the same solution. Eosinophil cDNA library filters were then washed two times with 2X SSC/0.1% SDS at room temperature, and two times with 2X SSC/0.1%

SDS

at 42 oC. Each wash was for 30 minutes. Filters were exposed overnight and positive plaques were picked in duplicate. Clones were further evaluated when positive in duplicate after the low stringency washes.

Characterization of cDNA Clones Plaques were plaque purified, and DNA was isolated by a small scale phage lysis protocol (In: Current Protocols In Molecular Biology, Vol. 1, Suppl. 10, Ausubel, F.M. et .a~ -101al., Eds., (John Wiley Sons: New York, NY), page 1.13.7 (1991). The bacteriophage DNA was digested with EcoRI (site in arm of vector) and NotI. The inserts released by digestion were visualized on a gel, and were found to be approximately 1.6 kb in length. The -1.6 kb insert present in a plaque designated Mip-16 or M-16, was isolated using Gene Clean (Bioll0), and was cloned into the EcoRI and NotI sites of BluescriptO vector KS (Stratagene), which had been digested with both EcoRI and NotI to produce asymmetric ends. The ligated plasmid was introducted into XL1-Blue

E.

coli cells (Stratagene) made competent as described by Hanahan (Hanahan, (1985), In: DNA Cloning, Volume 1, D.M. Glover, Ed. (IRL Press: Washington, pp. 109- 135).

Dideoxy sequencing of the M-16/Bluescript construct was performed using a dideoxynucleotide sequencing kit obtained from USB (United States Biochemical, Cleveland, OH). The nucleotide sequence of this clone was determined to encode a novel protein with a high degree of homology to the MIP-la/RANTES receptor; however, from the sequence data, the clone did not appear to be full-length.

In order to identify a full-length clone, 15-20 additional plaques were isolated and purified, and the inserts present in the phage were characterized by restriction enzyme analysis and/or sequencing. Another

X

clone, designated M31, which was isolated was found to contain a -1.8 kb insert. The insert was cloned into the EcoRI and NotI sites of Bluescripte vector KS (Stratagene), Sand introduced into XL1-Blue E. coli cells (Stratagene) as 30 described above. DNA sequencing of this clone (M31 insert in Bluescript, referred to as M 3 1/Bluescript construct) was performed as described above, and revealed that it encoded a full-length receptor.

The M31 insert was released from the M31/Bluescript S 35 construct by digestion with EcoRI and NotI. The resulting *oo *oo o -102fragment was isolated using Gene Clean (Bioo01), and was inserted into the EcoRI and NotI sites of vector AprM9, which had been digested with both EcoRI and NotI to produce asymmetric ends. Vector ApM9 (de Fougerolles, A.R. et al., J. Exp. Med., 177: 1187-1192 (1993)) is a derivative of CDM8 (Invitrogen) containing the -lactamase from pBluescript and a polylinker from pSP64. The resulting construct, designated A31, was introduced into competent XL1-Blue cells.

The nucleotide sequence of the full-length cDNA and the predicted amino acid sequence of the encoded protein are shown in Figures 2A-2B (see also SEQ ID NO:3 and SEQ ID NO:4). The cDNA sequence shown in Figures 2A-2B was determined from clones A31 (bases 15-365 (numbering as in Figures 2A-2B)), and the M-16/Bluescript construct (bases 366 to 1152 (numbering as in Figures 2A-2B)). A comparison of the amino acid sequence of the novel receptor with other proteins revealed that the novel receptor and the MIP-la/RANTES receptor share 62% sequence identity, and the novel receptor and the MCP-1 receptor share 50.57% sequence identity. Sequence identity was determined using the Wisconsin UW GCG package (program gap), with the Needleman and Wunsch algorithm (Needleman and Wunsch, J. Mol. Biol.

48:443-453 (1970)).

25 Northern Analysis RNA for Northern analysis was obtained from a patient having hyper-eosinophilia. The eosinophils were isolated as described (Costa, et al., J. Clin. Invest., 91: 2673 (1993)). Total eosinophil RNA was isolated using standard procedures (In: Current Protocols In Molecular .Biology, Vol. 1, Ausubel, F. M. et al., Eds., (John Wiley Sons: New York, NY) page 4.2.2-4.2.3 (1991)). The total RNA was fractionated on a 1% agarose gel, and then blotted o -103onto GeneScreen filters (New England Nuclear). Filters were probed at high stringency according to the manufacturer's protocol for high stringency washing of Gene Screen blots (New England Nuclear).

Several Northerns were prepared. One involved probing with the EcoRI-NotI fragment of the M16/Bluescript construct, and others were probed with the EcoRI-NotI fragment from clone A31. Both EcoRI-NotI fragments include the 3' untranslated regions. Probes were labeled with 32

P

using a random primer labeling kit (Boehringer Mannheim Biochemicals).

The Northern blots each revealed a very strong signal of approximately 1.8 kb in total human eosinophil

RNA.

This result indicates that the A31 RNA is expressed at very high levels in eosinophils from this patient.

EXAMPLE 9 Expression of cDNA encoding Eos L2 receptor and LiQand Binding Studies Constructs Vectors A31 (described above) and A31-pcDNA3 were used for expression and binding analyses. To construct A31-pcDNA3, vector A31 was digested with EcoRI and NotI, the -1.8 kb insert was isolated using Gene Clean (Bioll), and was inserted into the EcoRI and NotI sites of vector 25 pcDNA-3 (Invitrogen), which had been digested with both EcoRI and NotI. The ligated construct, designated A31pcDNA3, was introduced into competent XL1-Blue cells.

Transient Transfections Transient transfections using A31 in the kidney cell 30 line 293 initially suggested high affinity binding of A31 with radioactive RANTES. These initial binding studies oo -104have been difficult to reproduce. Accordingly, stable cell lines have subsequently been produced with A31/pcDNA3 stably integrated into both RBL (rat basophilic leukemia) and 293 cells. RBL cells (Accession No. ATCC CRL 1378) were obtained from the American Type Culture Collection (ATCC), 12301 Parklawn Drive, Rockville, MD 20852, and 293 cells (Accession No. ATCC CRL 1573) were a gift from I.

Charo, Gladstone Cardiovascular Institute.

Stable Cell Lines Stable cell lines were constructed as follows.

A31-pcDNA3 was linearized by digestion with NotI. The linearized plasmid was introduced into RBL and 293 cells by electroporation. Confluent 293 and RBL cells growing in 100 X 20 mm plates were trypsinized, resuspended in 1 cc of phosphate buffered saline (PBS) and electroporated in a 0.4 cm cuvette (BioRad) with settings of 960 microfarads and 250 volts. Stable transfectants were isolated by positive selection in medium containing geneticin. Specifically, the cells were first cultured in DMEM (BRL), 10% fetal calf serum for several days, and then were switched to DMEM, fetal calf serum with 0.9 mg/cc of Geneticin (BRL).

(DMEM,

Dulbecco's Modified Eagle's Medium). After 3 weeks, surviving colonies were isolated sterilely with cloning cylinders, and individual clones were grown in individual 25 wells in DMEM, 10% fetal calf serum with 0.9 mg/cc of Geneticin (BRL).

Surviving clones which expressed A31 RNA at high levels were detected by Northern analysis. 120 stable transfectants of the RBL line, and 38 stable transfectants of the 293 cell line, were screened. Specifically,

RNA

from individual clones was isolated using the acid phenol method (Chomczynski, P. and N. Sacchi, Anal. Biochem., 162: 156-159 (1987)). RNA was fractionated by electrophoresis, blotted onto GeneScreen (New England Nuclear), and Northern S U a -105blots were probed according to the manufacturer's suggestion for high stringency wash. The EcoRI-NotI insert from plasmid A31 was isolated, radiolabeled with 32 p using the random primer labeling kit (Boehringer Mannheim Biochemicals), and used as a probe. RNA was quantified by ethidium bromide staining on gels. Untransfected 293 or RBL cells were used as negative controls for the corresponding transfectants.

Stable cell lines designated A31-293-#8, A31-293-#9, A31-293-17, and A31-293-#20 were subsequently found to express A31 RNA at very high levels relative to other lines. Clone A31-293-#20 which highly expresses the A31 message by Northern analysis, was selected for further study.

One RBL line was found to express low-medium amounts of RNA, but did not appear to bind RANTES under the conditions used (not shown).

Ligand Binding Stable clone A31-293-#20 was grown in quantities sufficient for binding assays. In particular, cells were grown in 100 mm plates in DMEM, 10% fetal calf serum, 0.9 mg/cc geneticin. Plates were grown to confluence, and membranes were prepared as follows. Culture medium was removed, and the cells were washed with phosphate buffered saline. Cells were harvested by washing with TEN (40 mM TRIS, pH 7.5, 1 mM EDTA, and 150 mM NaCl). Thecells were frozen in liquid nitrogen, thawed at room temperature, and the membrane fraction was collected by centrifugation in a conical tube for 10 minutes at 18,000 rpm. Each binding 30 point was determined using one-half of the membranes harvested from a single 100 mm plate grown to confluence.

2' I-labeled RANTES was purchased from New England Nuclear, and cold RANTES was purchased from Peprotech o *oooo -106- (Princeton, 1 5I-labeled MCP-3 was a gift from New England Nuclear, and cold MCP-3 was a gift from J. Van Damme, Rega Institute for Medical Research, University of Leuven, B-3000 Leuven, Belgium (see also, Opdenakker, G. et al., Biochem. Biophys. Res. Commun., 191(2): 535-542 (1993)). Binding assays were performed as described by Van Riper, G. et al., J. Exp. Med., 177: 851 (1993), with the following modifications. In particular, the binding to membranes of 0.125 nanomolar of 25-RANTES was performed in the presence of varying concentrations of unlabeled ligand.

Binding buffer was 50 mM Hepes, 1 mM CaC1 2 5 mM MgCl 2 BSA, pH 7.2. Radiolabeled and cold ligand were added simultaneously to the membranes (see above), and incubated for 1.5 hours at room temperature. The binding reaction was added to 2 cc of wash buffer (0.5 M NaC1, 50 mM Hepes, 1 mM CaCl 2 5 mM MgC1 2 0.5% BSA, pH mixed by vortexing, and then placed on polyethyleneimine-treated Whatman GFC filters. Filters were washed with an additional two ccs of wash buffer. Activity retained on filters after washing was determined by scintillation counting. Filters were placed in 5 cc of scintillation fluid and were then counted in a miniaxi-beta liquid scintillation counter (United Technologies, Packard, Downers Grove, IL). All points were determined in triplicate, except for the point at 2 nM, which was determined in duplicate.

The results of the assay indicated high affinity binding of RANTES to the receptor encoded by the A31 clone (Figure 19). Scatchard analysis of the data indicated a Kd of 2.5 nM for RANTES, which is what is expected in normal cells.

Binding of MCP-3 to membranes from clone A31-293-#20 was also assessed using the ligand binding assay described above for RANTES binding to A31-293-#20 membranes (Figure *o*O* oooo* *oo o -107- Binding reactions contained 0.125 nanomolar 125I labeled MCP-3.

In addition, specificity of binding was assessed by determining the extent to which labeled MCP-3 (bound in the absence of cold MCP-3), could be displaced by cold MCP-3 (Figure 21). All points were taken in duplicate.

The MCP-3 bound to membranes from untransfected cells could not be displaced by 12I-labeled MCP-3, indicating non-specific binding. In comparison, the MCP-3 bound to membranes from A31-293-#20 cells could be displaced by hot MCP-3, which is indicative of specific binding.

The results of these assays indicate that the receptor encoded by the A31 cDNA specifically binds human MCP-3.

Eauivalents Those skilled in the art will be able to recognize, or be able to ascertain, using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims.

o* o *g* o -108- SEQUENCE LISTING GENERAL INFORMATION: APPLICANT: Gerard, Craig Gerard, Norma P.

Mackay, Charles Ponath, Paul D.

Post, Theodore

W.

Qin, Shixin (ii) TITLE OF INVENTION: G-PROTEIN COUPLED RECEPTOR

GENE

(iii) NUMBER OF SEQUENCES: 18 (iv) CORRESPONDENCE

ADDRESS:

ADDRESSEE: Hamilton, Brook, Smith& Reynolds,

P.C.

STREET: Two Militia Drive CITY: Lexington STATE: MA COUNTRY:

USA

ZIP: 02173 COMPUTER READABLE FORM: MEDIUM TYPE: Floppy disk COMPUTER: IBM PC compatible OPERATING SYSTEM: PC-DOS/MS-DOS SOFTWARE: PatentIn Release 11.0, Version #1.30 (vi) CURRENT APPLICATION

DATA:

APPLICATION NUMBER: FILING DATE:

CLASSIFICATION:

(vii) PRIOR APPLICATION

DATA:

APPLICATION NUMBER: US 08/375,199 FILING DATE: 19-JAN-1995 (viii) ATTORNEY/AGENT

INFORMATION:

NAME: Brook, David E.

REGISTRATION NUMBER: 22,592 REFERENCE/DOCKET NUMBER: LKS94-05A PCT (ix) TELECOMMUNICATION

INFORMATION:

TELEPHONE: 617-861-6240 TELEFAX: 617-861-9540 INFORMATION FOR SEQ ID NO:1: SEQUENCE CHARACTERISTICS: LENGTH: 1689 base pairs TYPE: nucleic acid STRANDEDNESS: double TOPOLOGY: linear (ii) MOLECULE TYPE: DNA (genomic) r -109- (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 1: AATCCTTTTi

GCTATC&CA!

Gr.ATGATTAV.

ATGACAACC'

GCCTGCTCl

TACTCCCTGC

AAATACAGG)

CTGCTCTTCC

TTTGGCCATG

ATCTTTTTCA

GCCCTTC)GAG.

GCAGTGCTAG

ACTCTTTGCA

CTGAGAATGA

GGAATCATCA

ATTTTTGTCA

CTCTCTTCCT

CTGGTCATGC

TACGCCTTTG

CTCAT.GCACC

TCTGTCTCTC

AATTGCCTAA

CCTCTAAAAC

ATACACACAG

GCGCAGCGTA

TACCTATATT

AAACTTTTTA

CACAATACAA

GAAAAGCT

aCTGGCACCTI r GTGGCATCT.

r GCcTT.

r~ CACTAGATAC r' GTGAAAM~GC ;TGTTCACTGi L GGCTC0GAAl

:TCGTCACCC

GCATGTGTAJI

TAATCCTGCT

CCCGGACTGT

CAGCTCTTCC

GTGCTCTTTA

CCATCTTCTG

AIA~CGCTGCT

TCATGGCGGT

ATCAATccAT

TGGTGACAGA

TTGGAGAGAG

TGGGCAGATA

CATCCACALGC

AGAGGAAGGA

AGTCCTTCAA

CAGTAGCAGT

CTCATCATCA

TTAATGCAcc

TATTTTATAC

TAAGTTAACT

TGATATCCTT TTGAAATTCA TGTTAAAGAA

TCCCTAGGCT

r TGTTGAGTAI r GGGATTTA AGTTGAGAcX

TGATACCAG)

GvGGCCTCTT

TATGACCAAC

TCCATTCTGG

GCTCCTCTCA

GACAIATcGAC

CACTTTTGGT

TGAATTTATC

CCCAGAGGAT

TCTCGTTCTc

GAGGTGCCCC

GITTTCATT

CTTATTTGGA

GGTGATCGCC

GTTCCGGAAG

CATCCCATTC

AGAGCCGGAA

CCAAGGAGAT

ACCTTCCAGT

AGATGCATGT

ACCTAAAAAG

TGAATGTTAG

ATTAACTTCA

ATTTTATTTT

-ATGAATAAA,

rTTTTCTT=T

TTTGGTACCI

LGCACTGATGC

PGGCAATG=G

ATCTACCTGc

ATCCACTATG

GGGTTTTATC

:AGGTACCTG

GTCATCACCA

TTCTATGArjA

ACAGTATATA

CCTCTGCTCG

AGTAAAAAAA

TTCTGGACAC

AATGACTGTG

TACTcccAcT

TACCTGCGCC

CTTCCTAGTG

CTCTCTATTG

NAAGCAAACA

GCAACACTGA

ACCCTAAGGT

CAQAGCTTTG

ATAGTTACTA

GCCAGCTATT

CTAATGTGCC

r CAACTGGTGT r' CTATcAcAGG

CATCCTACTA

CCCAGTTTGT

TGGTGGTGAT

TCAACCTGGc TCAGGoGWCA

ACACAGGCT

CCATTGTCCA

GCATCGTCAC

CTGAAGAGTT

GCTG-GAGGCA

TTATGGCCAT

AGTACAAGGc

C.CTACAATGT

AGCGGACGA

C

GCTGCATGA

C

ACTTCTTCCAC

AGAAGCTGGA

TGTTTTAGGT

A

CATTAAGCCT

T

AGCTCTTAAG

A

CATTACCACA

G

CTTcTCTCTCT

TATGCCGCTAC

ATATAAATAA

A

TAGTTCTTTC

C

GTTTTACoAA~

GAGAAGTGA

1

TGATGACGTG

GCCCCGCTG

GATCCTCATA

CATTTCGGAC

TAACTGGGTT~

GTACAGCGAG

TGCTGTGTTT

CTGGGGCCTG

GTTTGAAGAG

rTTCCACACT

CTGCTACACA

:ATCCGGCc

;GCTATCCTT

;CATCTGGAC

CCGGTGATC

:AGGCACTTG

LGAACCAGc

IGATGCAGAJA

CCACACTCA

CACTGAAAT

GCCAGGGCT

AAAATGAGT

AAAAAGGTA

ACATTTTCA

CTGCTTAAT

120 180 240 300 360 420 480 540 600 660 720 780 840 900 960 1020 1080 1140 1200 1260 1320 1380 1440 1500 1560 1620 .1680 1689 q -110- INFORMATION FOR SEQ ID NO:2t SEQUENCE

CHARACTERISTICS:

LENGTH: 355 amino acids TYPE: amino acid

STRANDEDNESS:

TOPOLOGY: linear (ii) MOLECULE TYPE: protein (xi) SEQUENCE DE SCRIPTION: SEQ ID NO:2i: Met Thr Thr Ser Leu Asp Thr Val Glu Thr Phe Gly Thr Thr 1 5 10' Ser Tyr Tyr Met Leu Leu Leu His Tyr Ile Arg.

145 Ala Leu Tyr Val ThrJ 225 Ile Asp Ala Lou s0 Arg Lou Asn His Asp 130 Thr Val Phe Ser Leu 210 4 eu he Asp Gin Gly Ile Phe Trp Thr 115 Arg Val Leu Glu Trp 195 Pro Lou Val I Val Phe Asn Met Leu Val 100 Gly Tyr Thr Aia ;iu

ISO

krg 4 eu Wrg le

L

Giy Leu Lou cys IVal Val Thr Val Phe Leu Leu Phe Ala 165 Thir His Lou cys Met 245 Pro Val Asn 70 Thr Gly Tyr Ala Gly 150 Leu Leu Phe Val Pro 230 Ala Pro Val S5 Ile Leu His Ser Ile 135 Val Pro Cys His Met 215 Ser Val Leu 40 Val Tyr Pro Gly Giu 120 Val1 Ile Glu Ser Giu Lys 25 Tyr Ser Ala Leu Thr ArcS Phe Thr Met Ile Leu Ile Lys Leu Phe Met 105 Ile His Thr Phe Ala 185 Leu Trp 90 Cys Phe Ala Ser Ile 170 Leu Asn 75 Ile Lys Phe Val Ile 155 Phe Tyr 60 Leu His Leu Ile Phe 140 Val Tyr Pro Ala Tyr Leu Ile 125 Ala Thr Giu Giu Tyr Ile Val Ser 110 Leu Leu Trp Thr Asp Ala Phe Arg Ser Arg Cly Leu Arg Gly Giu 175 Thr Leu Gly Arg Asp Gly Phe Thr Ala Leu 160 Glu.

Vtal 9 Thr Leu Arg M et Thr Ile Phe Cys Leu 200 205 Ala Lys Phe Ile Lys Phe Cys Lys Ile 250 Tyr Tyr 235 Phe Ile Ile Pro Ile Lys Arg Leu 240 Tyr Asn 255 Val Ala Ile Lou Lou .Ser Ser Tyr Gin Ser Ile Lou Phe Gly Asn Amp 260 265 270 Cym Glu Arg Thr Lye Him Leu Asp Leu Val Met Leu Val Thr Glu Val 275 280 285 Ile Ala Tyr 5cr Him Cym Cym Met Ann Pro Val Ile Tyr Ala Phe Val 290 295 300 Gly Giu Arg The Arg'Lym Tyr Lou Arg His Phe Ph. His Arg. His Lou 305 310 .315 320 Lou Met His Lou Gly Arg Tyr Ile Pro Phe Lou. Pro Ser Giu Lys Lou 325 330 335 Glu Arg Thr Ser Ser Val Ser Pro Ser Thr Ala Giu Pro Giu Lou Ser 340 345 350 Ile Val The 355 INFORMATION FOR SEQ ID NO:3: SEQUENCE

CHARACTERISTICS:

LENGTH: 1193 base pairs TYPE: nucleic acid STRANDEDNESS: double TOPOLOGY: linear (ii) MOLECULE TYPE: cDNA (ix) FEATUR~E: NAME/KEY:

CDS

LOCATION: 92. .1156 (xi) SEQUENCE DESCRIPTION: SEQ ID NO:3: TTGTGCTTAT CCGOCAGA ACTTATCGA ATACAATAGA AGACCCACGC GTCCGGTTT TACTTAGAAG AGATTT TCAG GGAGAAGTGA A ATO ACA ACC TCA CTA GAT ACA 112 Met Thr Thr Ser Leu Asp Thr GTT GAG ACC TTT GGT ACC ACA TCC TAC TAT GAT GAC OTG GGC CTG CTC 160 Val Glu Thr Ph. Gly Thr Thr Ser Tyr Tyr Amp Asp Val Gly Leu Lou 15 TGT GAA AAA GCT GAT ACC AGA GCA CTG ATG GCC CAG TTT GTG CCC CCG 208 .Cys Glu Lye Ala Asp Thr Arg Ala Lou Met Ala Gin Phe Val Pro Pro 30 CTG; TAC.TCC CTG GTO TTC ACT GTG CCC CTC TTG GCC AAT GTG GTG GTO 256 *Lou Tyr Ser Leu Val Phe Tihr Val Gly Lou Lou Gly Ann Val Val Val 45 s0 GTG ATO ATC CTC ATA AAA TAC AGO AGO CTC CGA ATT ATG ACC AAC ATC 304 Val Met Ile Leu Ile Lys Tyr Arg Arg- Lou Arg Ile Met.Thr Asn Ile 65 -112-; TAC CTG CTC AAC CTG GCC ATT TCG GAC CTG CTC TTC CTC GTC ACC Tyr Leu Lou Aen Leu Ala Ile Ser Asp Lou Lou Phe Lou Val Thr Lou s0 CCA TTC TOG ATC CAC TAT GTC AGO GOG CAT AAC TGG OTT TTT CCC CAT 400 Pro Phe Trp Ile His Tyr Val Arg Gly His Asa Trp Val The Gly His 95 -100 GGC ATG TGT AAG CTC CTC TCA GGG TTT -TAT CAC ACA GGC TTG TAC AGC 448 Gly Met CYs LYS Lou Lou Ser Gly Phe Tyr His Thr Gly Lou Tyr Ser 105 110 115 GAG ATC.TTT TTC ATA ATC CTO CTG ACA ATC GAC AGO TAC CTG CCC ATT 496- Glu Ile Phe Phe Ile Ile Lou Lou Thr Ile Asp Arg Tyr Leu Ala Ile 120 125 130 135 GTC CAT OCT GTO TTT GCC CTT CCA GCC CGC ACT OTC ACT TTT-GOT GTC S44 Val His Ala Val Phe Ala Lou Arg Ala Arg Thr Val Thr The Gly Val 140 145 150 ATC ACC AGC ATC GTC ACC TGG GGC CTO GCA GTG CTA GCA GCT CTT CCT' 592 Ile Thr Ser Ile Val Thr Trp Gly Leu Ala Val Leu Ala Ala Leu Pro 155 '160 165 GAA TTT ATC TTC TAT GAG ACT GAA GAG TTG TTT GAA GAG ACT CTT TGC 640 Clu Phe Ile Phe Tyr Oiu Thr Giu Ciu Lou Phe Glu Glu Thr Lou Cys 170 175 180 ACT OCT CTT TAC CCA GAG CAT ACA GTA TAT AGC TGG AGO CAT TTC CAC 688 Sor Ala Lou Tyr Pro Giu Asp Thr Val Tyr Ser Trp Arg His Phe His 185 190 195 ACT CTG AGA ATG ACC ATC TTC TOT CTC OTT CTC CCT CTG CTC OTT ATO 736 Thr Lou Arg Met Thr Ile Phe Cys Lou Val Lou Pro Leu Lou Val. Met 200 205 210 215 0CC ATC TOC TAC ACA OGA ATC ATC AAA ACG CTG CTO ACO TOC CCC ACT 784 Ala Ile Cys Tyr Thr Gly leIle Lye Thr Lou Lou Arg Cys Pro Ser 220 225 230 AAA AA.A AAO TAC AAG CCC ATC C00 CTC ATT TTT GTC ATC ATO C GTG 832 Lys-Lys Lye Tyr Lys-.Ala Ile Arg Lou Ile Phe Val Ile Met Ala Val 235 240 245 TTT TTC ATT TTC TGO AC A CCC TAC AAT GTG OCT ATC CTT CTC TCT TCC 880 ***Phe Phe Ile Phe Trp, Thr Pro Tyr Asn Val Ala Ile Lou Lou Ser Sor 250 255 260 Tyr Gin Sor Ile Lou The Oly Asn Asp Cys Giu Arg Sor Lye His Lou 265 270 275 *GAC CTG GTC ATGC TO GTG ACA GAG OTO ATC CCC TAC TCC CAC TGC TGC 976 Asp Lou Val Met Lou Vai Thr Glu Val Ile Ala Tyr Ser His Cys Cys *280 285 290 295 ATO AAC CCG GTO ATC TAC GCC TTT OTT GCA GAG AGO TTC COO AAO TAC 1024 Met Aen Pro Val Ile Tyr Ala Phe Val Gly Glu Arg Phe Arg Lys-Tyr 300 305 310 CTG CGC CAC TTC TTC CAC AGG CAC TTG CTC ATG CAC CTG GOGC AGA TAC 1072 *Leu Arg His Phe Phe His Arg His Leu Leu Met His Leu Gly Arg Tyr 315 320 325 ATC CCA TTC CTT CCT AGT GAG AAG CTG GMA AGA ACC AGC TCT GTC TCT 1120 Sle Pro Ph. Leti Pro Ser Glu Lys Lou Giu Arg Thr Ser Ser Val Ser 330 335 340 CCA TCC ACA GCA GAG CCG GAA CTC TCT ATT GTG TTT TAGGTAGATG 1166 Pro Ser Thr Ala Glu Pro Giu Leu Ser Ile Val Phe 345 350 355 CAGAAAATTG CCTAAAGAGG AAGGACC 1193 INFORMATION FOR SEQ ID NO:4: SEQUENCE

CHARACTERISTICS:

LENGTH: 355 amino acids TYPE: amino acid TOPOLOGY: linear (ii) MOLECULE TYPE: protein (xi) SEQUENCE DESCRIPTION: SEQ ID NO:4: Met Thr Thr Ser Lou Asp Thr Val Glu Thr Phe Gly Thr Thr Ser Tyr 10 Tyr Asp Asp Val Gly Leu Leu Cys Giu Lys Ala Asp Thr Arg Ala Leu 25 Met Ala Gin Ph. Val Pro Pro Leu Tyr Ser Leu Val Phe Thr Val Gly 40 Leu Leu Gly Asn Val Val Val Val Met Ile Leu Ile Lys Tyr Arg Arg 55 Leu Arg Ile Met Thr Asn Ile Tyr Leu Leu Asn Leu Ala Ile Ser Asp 70 75 Leu Leu Phe Leu Val- Thr Leu Pro Phe Trp Ile His Tyr Val Arg Giy 8590 His Aen Trp Val The Gly His Gly Met Cys Lys Leu Leu Ser Gly Phe 100 105 110.

*Tyr His Thr Gly Lou'Tyr Ser Giu Ile Ph. Phe Ile Ile Leu Leu Thr 115 120 125 Ile Asp Arg Tyr Lou Ala Ile Val His Ala Val Phe Ala Leu Arg Ala 130 135 140 Arg Thr Val Thr Phe Gly Val Ile Thr Ser Ile Val Thr Trp Gly Leu 145 ISO0 155 160 Ala Val Leu Aia'Ala Leu Pro Giu Phe Ile Phe Tyr Glu Thr Giu Giu 165 170 175 Lou Ph. Glu Giu Thr Leu Cys Ser Ala Leu Tyr Pro Giu Asp Thr Val 180 185 190 -114- Tyr Ser 2!rP Arg His The His Thr Lou Ar; Met Thr Ile The Cys Lou 195 200 205 Val Lou Pro Lou Lou Val MetAl iCyTrThGyleleLy 210 215 220l y TrTrGy l l y Thr Lou Leu Ar; Cys Pro Ser Lye Lye Lye Tyr Lys Ala Ile Ar; Lou 225 230 -235 240 le Phe Val Ile Met Ala Val Phe The 1i1 Phe Trp Thr Pro T!yr Aen 245 250 255 Val Ala 110 Leu Lou Ser Ser Tyr Gin Ser Ile Lou Phe Gly Aen Asp 260 265 270 CYs Glu Ar; Ser Lys His Lou-Asp Lou Val Met Leu ValTrGlVa 275 280 285 h l a Ile Ala Tyr Ser His Cys Cys Met Asn Pro Val Ile Tyr Ala'Phe Val 290 29S 300 Gly Glu Ar; The Ar; LyS. Tyr Leu Arg His Phe Phe His Arg IHis 35310 315 Leu Met His Leu Gl1y Arg Tyr Ile Pro Phe Leu Pro SeGu y 325 330erGu y Leu 320 a a a.

a a a a Clu Ar; Thr Ser -Ser Vai Ser Pro Ser Thr Ala Glu Pro Giu Leu Ser 340 345 350S Ile Val Phe 355 INFORM~ATION FOR SEQ ID SEQUENCE

CHARACTERISTICS:

LENGTH: 1116 base pairs TYPE: nucleic acid STRANDEDNESS: double TOPOLOGY: linear (xi) SEQUENCE DESCRIPTION: SEQ ID CAGGGAGAAG TGAA&TGACA ACCTCACTAG ATACAGTTJA* GACCTTTGGT

ACCACATCCT

ACTATGATGA CGTGGGCCTG CTCTGTGA AAGCTGATAC CAGAGCACTG

ATGGCCCAGT

TTGTGCCCCC GCTGTACTCC CTGGTGTTCA CTGTGGGCCT CTTGGGCAAT GTGGTGGTQc TGATGATCCT CATAAAATAC AGGAGGCTCC GAATTATGAC CAACATCTAC

CTGCTCAACC

TGGCCATTTC GGACCTGCTC TTCCTCGTCA CCCTTCCATT CTGGATCCAC

TATGTCAGG

G"GCATA&CTG GGTTTTTGGC CATGGCATGT GTAAGCTCCT CTcAooTT

TATCACACAG

GCTTGTACAG CGAGATCTTT TTCATAATCC TGCTGACAAT CGACAGGTAC CTGccATTG TCCATGCTGT GTTTGCCCTT CGAGCCCGGA CTGTCACTTT TGGTGTCATC

ACCAGCATCG

TCACCTGGGG CCTGGCAGTG CTAGCAGCTC TTCCTGAATT TATCTTCTAT

GAGACTGAAG

120 180.

-240 300 360 420 480 540 -115- AGTTGTTTGA AGAGACTHTT TGCAGTGCTC

TTTACCCAGA

GSSATTTCCA CACTCTGAGA ATGACCATCT

TCTGTCTCGT

CCATCTGCTA CACAGGAT ATCAAAACGC

TGCTGAGGTG

AGGCCATCCG, GCTCATT!T GTCATCA2!GG

CGGTGTTTTT.

ATGTGGCTAT CCTTCTCTCTz TSCYWWYxAw

YCATCTTATT

MGAP.SMWqYK GGACCTGGTC ATGCTGGTGA

CAGAGGTGAT

TGAACCCGrGT GATCTAcGCC TTTGTTGGAG

AGAGGTTCCG

TCCACAGGCA cTTGCTCATG CACCTGGGCA

GATACATCCC

TGGAAAGAAC CAGCTCTGTC TCTCCATCCA

CAGCAGAGCC

AGGTAGATGC AGAAAATTG*C CTAAAGAGGA

AGGACC

INFORMATION FOR SEQ ID NO:6: SEQUENCE

CHARACTERISTICS:

LENGTH: 355 amino acids TYPE: amino acid

STRANDEDNESS:

TOPOLOGY: linear (ii) MOLECULE TYPE: protein

GGATACAGTA

TCTccTT

CCCCAGTAAA

CATTTTCTGG

TGGAAATGAC

CGCCTACTCC

GAAGTACCTG

ATTCCTTCCT

GGAACTCTCT

TATAGCTGA

CTCGTTATGG

AAAAAGTACA

ACACCCTjLCA

TGTGAGOGGM

CACTGCTGCA

CGCCACTTST

AGTGAGAAGC

AITTGTGTTTT

600 660 720 780 840 900 960 1020 1080 1116 (xi) Met

I

SEQUENCE DESCRIPTION: SEQ ID NO:6: Thr Thr Ser Leu Asp Thr Val Giu Thr Phe 5 10 Gly Thr Thr Tyr Asp Asp Val Gly Leu Leu Cys Giu Lys Ala Asp Thr 25 Met Ala Gin Phe Val Pro Pro Leu Tyr Ser Leu Val Phe 35 40 45 Lou Leu G-.y Asn Vai Val Val Val Met Ile leu Ile Lys s0 55 60 Leu Arg Ile Met Thr AS T1 Arg Thr Val Gly Tyr Arg Arg Ser Tyr is 65 0 1r Lu L.eu Asfl Leu Ala Ile Ser Asp 657075 Leu Leu Phe Leu Val Thr Leu Pro Phe Trp Ile His Tyr Val Arg Gly 90 His Ann Trp, Val Phe Gly His Gly Met Cys Lys Leu Leu Ser Gly Phe 100 105 110 Tyr His Thr Gly Lou Tyr Ser Glu Ile Phe Phe Ile Ile Leu Leu Thr 115 120 125 Ile Asp Arg Tyr Lou Ala Ile Val His Ala Val Phe AlaLeAgAl 130 135 140 eArAl Arg Thr Val Thr Phe Gly Val Ile Thr Ser Ile Val Thr Trp Gly Leu 145 150 155 160 -116- Ala Val Leu Ala Ala Leu Pro Glu Phe 11i 165 174 Leu Phe Giu Glu Thr Xaa Cys Ser Ala Le 180 185 Tyr Ser Trp Xaa Xaa Phe Hi. Thr Leu Ar5 195 200 Val Leu Pro Leu Leu Val.Met Ala Ile Cys 210 215 Thr Leu Leu Arg Cys Pro Ser Lys Lys Lys 225 230 Ile Phe Val Ile Met Ala Val Phe Phe Ile 245 250 Val Ala Ile Leu Leu Ser Xaa Xaa Xaa Xaa 260 265 Cys Giu Arg Xaa Xaa Xaa Xaa Asp Leu Val 275 280 Ile Ala Tyr Ser His Cys Cys Met Asn Pro 290 295 Gly Glu Arg Phe Arg Lys Tyr Leu Arg His 305 310 Leu Met His Lou Gly Arg Tyr Ile Pro Phe 325 330 Glu Arg Thr Ser Ser Val Ser Pro Ser Thr 340 345 Ile Val Phe 355 INFORMATION FOR SEQ ID NO:7: SEQUENCE

CHARACTERISTICS:

LENGTH: 25 base pairs TYPE: nucleic acid STRUANDEDNESS: single TOPOLOGY: linear (ix) FEATURE: AA) NAME/KEY: modified-base LOCATION: 19 OTHER INFORMATION: /mod-base= i (ix) FEATURE: NAME/KEY: modified-base LOCATION: 24 OTHER INFORMATION: /mod-base- i (xi) SEQUENCE DESCRIPTION: SEQ ID NO:7: TACCTGCTSA ACCTGGCcNT

GGCNG

Phe Tyr Glu Tyr Pro Giu Met Thr Ile 205 Tyr Thr Gly 220 Tyr Lys Ala 235 Phe Trp Thr Ile Leu Phe Met Leu Val 285 Val Ile Tyr 300 Xaa Phe His 315 Leu Pro Ser C Ala Glu Pro C Thr Glu Glu 175 Asp Thr Val 190 Phe Cys Lou Ile Ile Lys Ile Arg Leu 240 Pro Tyr Aen 255 Gly Aen Asp 270 Thr Giu Val Al~a Phe Val krg His Leu 320 liu Lys Leu 33S liU Leu Ser 3so -117- INFORMA~TION FOR SEQ ID MOSS: SE QUENCE

CHARACTERISTICS:

LENGTH: 25 base pairs TYPE: nucleic acid STRANPEDNESS: single TOPOLOGY: linear (ix) FEATURE: NAME/EY: modified base LOCATION, 9- OTHER INFORMATION: /uiod-bame i (ix)

FEATURE:

NAHE/KEYS modified-base LOCATION: 14 OTHER INFORMATION: /mod-base- i (xi) SEQUENCE DESCRIPTION: SEQ ID NO:S: ACCTGGcCCNT GGCNGACCTM CTCTT- INFORMATION FOR SEQ ID NO:9: SEQUENCE

CHARACTERISTICS:

LENGTH: 27 base pairs TYPE: nucleic acid STRANDEDNESS: single TOPOLOGY: linear (ix) FEATURE: NAME/KEY: modified-base LOCATION: 18S OTHER INFORMATION: /mod-base- i (xi) SEQUENCE DESCRIPTION: SEQ ID NO:9: GACCGYTACC TGGCCATNGT CCAYGCC 27 INFORMATION FOR SEQ ID NO:l0: SEQUENCE

CHARACTERISTICS:

LENGTH: 27 base pairs (B)'TYPE: nucleic acid STRANDEDNESS: single TOPOLOGY: linear (ix) FEATURE: NAME/KEY: modified-base LOCATION:o OTHER INFORMATION: /mod-basen i (xi) SEQUENCE DESCRIPTION: SEQ ID NO:l0: GGCRTGGACN ATGGCCAGGT ARCGGTC 27 INFORMA~TION FOR SEQ ID NOslij: i)SEQUENCE

CHARACTERISTICS:

LENGTH: 27 base pairs TYPE: nucleic acid STRANDEDNESS: single TOPOLOGY: linear (ix) FEATURE: NAME/KEY: modified-base LOCATION:

I

OTHER INFORMATION: /mod-base. i (ix) FEATURE: NAME/KEY: modified base LOCATION: 6 OTHER INFORMATION: /mod-base' i (ix) FEATURE: NAME/KEY: modified-base LOCATION: 16 OTHER INFORMATION: /mod-base- i (ix) FEATURE: NAME/KEY: modified-base LOCATION: 18 OTHER INFORMATION: /mod-base i (xi) SEQUENCE DESCRIPTION: SEQ ID NO:'1l: NACCANTTG TAGGGNRNCC ARM.RAG 2 INFORMATION FOR SEQ ID NO:12: 2 SEQUENCE

CHARACTERISTICS:

LENGTH: 28.base pairs TYPE: nucleic acid STRANDEDNESS: single TOPOLOGY: linear

FEATURE:

NAME/KEY: modified-base LOCATION: 8- OTHER INFORMATION: /mod-base.' i (ix) FEATURE:* NAME/KEY: modified base LOCATION: OTHER INFORMATION: /modbase= i (ix) FEATURE: NAME/KEY: modified base LOCATION: 23 OTHER INFORMATION: /mdbae- (xi) SEQUENCE DESCRIPTION: SEQ ID NO:12: TGTAGGGNPJN CCARKARAGR AGNARGAA 28 INFORMATION FOR SEQ ID NO:13: SEQUENCE

CHARACTERISTICS:

LENGTH: 27 base pairs TYPE: nucleic acid STRANDEDNESS: single TOPOLOGY: linear (ix) FEATURE: NAME/KEY: modified-base LOCATION: 12 OTHER INFORMATION: /mod basen i (1x) FEATURE: NAME/KEY: modified-base LOCATION: OTHER INFORMATION: /mod-base= i (ix)

FEATURE:

NAME/KEY: modified-base LOCATION: 16 OTHER INFORMATION: /modbase= i (xi) SEQUENCE DESCRIPTION: SEQ ID NO:13: GAAGGCGTAG ANSANNGGGT TGASGCA 27 INFORMATION FOR SEQ ID NO:14: SEQUENCE

CHARACTERISTICS:

LENGTH: 25 base pairs TYPE: nucleic acid STRANDEDNESS: single TOPOLOGY: linear (ix)

FEATURE:

'NAME/KEY: modified-base LOCATION: 4- OTHER INFORMATION:. /mod-base= i (ik)

FEATURE:

NAME/KEY: modified-base LOCATION: 7- OTHER INFORMATION: /mod-base- j.

(1x)

FEATURE:

NAME/KEY: modified-base 4 4(B) LOCATION: 8 OTHER INFORMATION: /znod-base- i xi) SEQUENCE DECITO:SEQ ID NO:14: AGANSANGG GTTGASGCAG CWGTG -120- INFORMTION FOR, SEQ 1ID ()SEQUENCE

CHARACTERISTICS.

LENGTH: 48 base pairs TYPE: nucleic acid STRAI(DEDNESS: double TOPOLOGY: linear (ix) FEATURE: NAME/KEY:

CDS

LOCATION: 16..48 (xi) SEQUENCE DESCRIPTION: SEQ ID NO:ls: AAGCTTCCAG CAGCC ATGr, GAC TAC AAG GAC GAC GAT GAC AAA GM TTC 48 etAsp Tyr Lys Asp Asp Asp Asp Lys Glu Phe 1 INFORMATION FOR SEQ ID NO:16: SEQUENCE

CHARACTERISTICS:

LENGTH: 11 amino acids TYPE: aminlo acid TOPOLOGY: linear (ii) MOLECULE TYPE: protein (Xi) SEQUENCE DESCRIPTION: SEQ ID NO:16: Met Asp Tyr Lye Asp AspAsp Asp Lys Glu Phe 1S INFORMATION FOR SEQ ID NO:17: SEQUENCE

CHARACTERISTICS:

LENGTH: 27 base pairs TYPE: nucleic acid STRANDEDNESS: single TOPOLOGY: linear (xi) SEQUENCE DESCRIPTION: SEQ ID NO:17: TTAMGAM2C ACAMCCCC TAGATAC 2 INFORMATION FRSEQ ID No:18: (i SEQUENCE

CHARACTERISTICS:

LENGTH: 18 base pairs TYPE: nucleic acid STRANIDEDESS: single .9 TOPOLOGY: linear 9. 9 (xi) SEQUENCE DESCRIPTION: SEQ ID NO:18: .CATAGTGGAT. CChcATG 18

Claims (61)

1. A method of identifying an inhibitor of a mammalian C-C chemokine receptor 3 comprising: a) combining a compound to be tested, an isolated protein comprising a naturally S occurring mammalian C-C chemokine receptor 3, and a ligand of said receptor under conditions suitable for binding of ligand to said receptor; and b) detecting or measuring the formation of a complex between said receptor and said ligand, wherein inhibition of complex formation by the compound is indicative that the o compound is an inhibitor and wherein said receptor specifically binds a natural ligand of a naturally occurring mammalian C-C chemokine receptor 3.

2. The method of claim 1, wherein the ligand in step a) is a natural ligand selected from the group consisting of RANTES and MCP-3.

3. The method of claim 1, wherein the ligand in step a) is labeled with a detectable label.

4. The method of any one of claims 1-3, wherein the isolated mammalian C-C chemokine receptor 3 is a recombinant protein. A method of identifying an inhibitor of a mammalian C-C chemokine receptor 3 Scomprising: I a) combining a compound to be tested, a host cell expressing a recombinant 20 protein comprising a naturally occurring mammalian C-C chemokine receptor 3, and a ligand of said receptor under conditions suitable for binding of ligand to said receptor; and b) detecting or measuring the formation of a complex between said receptor and said ligand, wherein inhibition of complex formation by the compound is indicative that the compound is an inhibitor and wherein said receptor specifically binds a natural ligand of a naturally occurring mammalian C-C chemokine receptor 3. S° 6. The method of claim 5, wherein the ligand in step a) is a natural ligand selected from the group consisting of RANTES and MCP-3. 7: The method of claim 5, wherein the ligand in step a) is labeled with a detectable label. 3o 8. The method of claim 5 or 6, wherein the mammalian C-C chemokine receptor 3 can mediate cellular signalling and/or a cellular response, and the formation of a complex is monitored by detecting or measuring a signalling activity or cellular response of said receptor in response thereto.

9. The method of any one of claims 5-8, wherein the compound to be tested is an S//antibody or antibody fragment. [I :\Day Lib\LI B FF]00928spec.doc:gcc 122 A method of identifying an inhibitor of a mammalian C-C chemokine receptor 3 comprising: a) combining a compound to be tested, a ligand or promoter of said receptor, and a host cell expressing a recombinant protein comprising a naturally occurring mammalian C-C chemokine receptor 3 under conditions suitable for detecting a ligand- or promoter-induced response; and b) determining the ability of the test compound to inhibit said response, wherein inhibition of a ligand- or promoter-induced response by the compound is indicative that the compound is an inhibitor and wherein said receptor specifically binds a natural o ligand of a naturally occurring mammalian C-C chemokine receptor 3.

11. The method of claim 10, wherein the ligand in step a) is a natural ligand selected from the group consisting of RANTES and MCP-3.

12. The method of claim 10, wherein the ligand in step a) is labeled with a detectable label.

13. The method of claim 10 or 11, wherein the response is monitored by detecting or measuring chemotaxis.

14. The method of claim 10 or 11, wherein the response is monitored by detecting or S. measuring exocytosis or degranulation.

15. The method of any one of claims 10-14, wherein the compound to be tested is an 20 antibody or antibody fragment.

16. A method of identifying an inhibitor of a human C-C chemokine receptor 3 comprising: a) combining a compound to be tested, a ligand of a human C-C chemokine receptor 3, and an isolated protein comprising a naturally occurring human C-C chemokine receptor or (ii) a polypeptide which has at least about 80% amino acid sequence identity with SEQ 5 ID NO:2 or SEQ ID NO:6 under conditions suitable for binding of ligand to said protein or said polypeptide; and 9 9 b) detecting or measuring the formation of a complex between said receptor or said polypeptide and said ligand, wherein inhibition of complex formation by the compound is indicative that the compound is an inhibitor and wherein said receptor and said polypeptide specifically bind a natural ligand of a naturally occurring human C-C chemokine receptor 3.

17. The method of claim 16, wherein said polypeptide has at least about 90% amino acid sequence identity with SEQ ID NO:2 or SEQ ID NO:6. RA 18 The method of claim 16 or 17, wherein the ligand in step a) is a natural ligand selected from the group consisting of RANTES and MCP-3. [I :\Day L i b\LI B FF] 0092 8spec.doc:gcc 123

19. The method of claim 16 or 17, wherein the ligand in step a) is labeled with a detectable label. A method of identifying an inhibitor of a human C-C chemokine receptor 3 comprising: a) combining a compound to be tested, a ligand of said receptor, and a host cell expressing a recombinant protein comprising a naturally occurring human C-C chemokine receptor or (ii) a polypeptide which has at least about 80% amino acid sequence identity with SEQ ID NO:2 or SEQ ID NO:6 under conditions suitable for binding of ligand to said receptor or said polypeptide; and b) detecting or measuring the formation of a complex between said protein or said o polypeptide and said ligand, wherein inhibition of complex formation by the compound is indicative that the compound is an inhibitor and wherein said receptor and said polypeptide specifically bind a natural ligand of a naturally occurring human C-C chemokine receptor 3.

21. The method of claim 20, wherein said polypeptide has at least about 90% amino acid sequence identity with SEQ ID NO:2 or SEQ ID NO:6.

22. The method of claim 20 or 21, wherein the ligand in step a) is a natural ligand selected from the group consisting of RANTES and MCP-3.

23. The method of claim 20 or 21, wherein the ligand in step a) is labeled with a detectable label.

24. The method of any one of claims 20-22, wherein the protein can mediate cellular signalling and/or a cellular response, and the formation of a complex is monitored by detecting or measuring a signalling activity or cellular response of said protein in response thereto. The method of any one of claims 20-24, wherein the compound to be tested is an antibody or antibody fragment.

26. A method of identifying an inhibitor of a human C-C chemokine receptor 3 comprising: a) combining a compound to be tested, a ligand or promoter of said receptor, and a host cell expressing a recombinant protein comprising a naturally occurring human C-C chemokine receptor or (ii) a polypeptide which has at least about 80% amino acid sequence 0 4 identity with SEQ ID NO:2 or SEQ ID NO:6 under conditions suitable for detecting a ligand- or promoter-induced response; and b) determining the ability of the test compound to inhibit said response, wherein inhibition of a ligand- or promoter-induced response by the compound is indicative that the compound is an inhibitor and wherein said receptor and said polypeptide RAE specifically bind a natural ligand of a naturally occurring human C-C chemokine receptor 3. [l:\Day L i b\LI B FF] 0092 8spec.doc:gcc I I o, 124

27. The method of claim 26, wherein said polypeptide has at least about 90% amino acid sequence identity with SEQ ID NO:2 or SEQ ID NO:6.

28. The method of claim 26 or 27, wherein the ligand in step a) is a natural ligand selected from the group consisting of RANTES and MCP-3.

29. The method of claim 26 or 27, wherein the ligand in step a) is labeled with a detectable label. The method of claim 26 or 27, wherein the response is monitored by detecting or measuring chemotaxis.

31. The method of claim 26 or 27, wherein the response is monitored by detecting or c1 measuring exocytosis or degranulation.

32. The method of any one of claims 26-31, wherein the compound to be tested is an antibody or antibody fragment.

33. A method of identifying an inhibitor of a human C-C chemokine receptor 3 comprising: a) combining a compound to be tested, an isolated protein comprising a naturally occurring human C-C chemokine receptor 3, and a ligand of said receptor under conditions suitable for binding of ligand to said receptor; and b) detecting or measuring the formation of a complex between said receptor and S said ligand, wherein inhibition of complex formation by the compound is indicative that the 2 compound is an inhibitor and wherein said receptor specifically binds a natural ligand of a naturally occurring human C-C chemokine receptor 3. 34 The method of claim 33, wherein the ligand is RANTES. The method of claim 33, wherein the ligand is MCP-3.

36. The method of claim 33, wherein the ligand is eotaxin.

37. The method of claim 33, wherein the ligand is labeled with a detectable label.

38. The method of any one of claims 33-37, wherein the isolated human C-C chemokine receptor 3 is a recombinant protein.

39. A method of identifying an inhibitor of a human C-C chemokine receptor 3 comprising: a) combining a compound to be tested, a host cell expressing a recombinant protein comprising a naturally occurring human C-C chemokine receptor 3, and a ligand of said receptor under conditions suitable for binding of ligand to said receptor; and b) detecting or measuring the formation of a complex between said receptor and said ligand, [I:\DayLib\LIBFF]00928spec.doc:gcc 125 wherein inhibition of complex formation by the compound is indicative that the compound is an inhibitor and wherein said receptor specifically binds a natural ligand of a naturally occurring human C-C chemokine receptor 3. The method of claim 39, wherein the ligand is RANTES.

41. The method of claim 39, wherein the ligand is MCP-3.

42. The method of claim 39, wherein the ligand is eotaxin.

43. The method of claim 39, wherein the ligand is labeled with a detectable label.

44. The method of any one of claims 39-42, wherein the naturally occurring human C-C chemokine receptor 3 can mediate cellular signalling and/or a cellular response, and the io formation of a complex is monitored by detecting or measuring a signalling activity or cellular response of said receptor in response thereto. The method of any one of claims 39-44, wherein the compound to be tested is an antibody or antibody fragment.

46. A method of identifying an inhibitor of a human C-C chemokine receptor 3 comprising: a) combining a compound to be tested with a host cell expressing a recombinant protein comprising a naturally occurring human C-C chemokine receptor 3, and a ligand or promoter of said receptor under conditions suitable for detecting a ligand- or promoter-induced response; and b) determining the ability of the test compound to inhibit said response, 0* wherein inhibition of a ligand- or promoter-induced response by the compound is indicative that the compound is an inhibitor and wherein said receptor specifically binds a natural ligand of a naturally occurring human C-C chemokine receptor 3.

47. The method of claim 46, wherein the ligand is RANTES.

48. The method of claim 46, wherein the ligand is MCP-3.

49. The method of claim 46, wherein the ligand is eotaxin.

50. The method of claim 46, wherein the ligand is labeled with a detectable label.

51. The method of any one of claims 46-49, wherein the response is monitored by S detecting or measuring chemotaxis.

52. The method of any one of claims 46-49, wherein the response is monitored by detecting or measuring exocytosis or degranulation.

53. The method of any one of claims 46-52, wherein the compound to be tested is an antibody or antibody fragment.

54. The method of any one of claims 1-4, 5-8, 10-14, 16-19, 20-24, 26-31, 33-38, 39-44 or 46-52, wherein the compound to be tested is an organic molecule. [I:\DayLib\LIBFF]00928spec.doc:gcc 126 The method of any one of claims 1, 5, 10, 15, 17, 20, 21, 26 or 27, wherein the ligand in step a) is eotaxin.

56. A method of identifying an inhibitor of a mammalian C-C chemokine receptor 3 comprising: a) combining a compound to be tested, an isolated protein comprising a mammalian C-C chemokine receptor 3 encoded by a nucleic acid which hybridizes under high stringency conditions with a nucleic acid selected from the group consisting of SEQ ID NO:1, SEQ ID NO:5, the complement of SEQ ID NO:1 and the complement of SEQ ID NO:5, and a ligand of said receptor under conditions suitable for binding of ligand to said receptor; and to b) detecting or measuring the formation of a complex between said receptor and said ligand, wherein inhibition of complex formation by the compound is indicative that the compound is an inhibitor.

57. The method of claim 56, wherein said ligand is selected from the group consisting of is RANTES and MCP-3.

58. The method of claim 56, wherein said ligand is eotaxin.

59. A method of identifying an inhibitor of a mammalian C-C chemokine receptor 3 .comprising: a) combining a compound to be tested, a host cell expressing a recombinant protein comprising a mammalian C-C chemokine receptor 3 encoded by a nucleic acid which hybridizes under high stringency conditions with a nucleic acid selected from the group consisting of SEQ ID NO:1, SEQ ID NO:5, the complement of SEQ ID NO:1 and the complement of SEQ ID NO:5, and a ligand of said receptor under conditions suitable for binding of ligand to said receptor; and b) detecting or measuring the formation of a complex between said receptor and said ligand, wherein inhibition of complex formation by the compound is indicative that the compound is an inhibitor. The method of claim 59, wherein said ligand is selected from the group consisting of RANTES and MCP-3.

61. The method of claim 59, wherein said ligand is eotaxin.

62. A method of identifying an inhibitor of a mammalian C-C chemokine receptor 3 comprising: RAL i a) combining a compound to be tested, a host cell expressing a recombinant protein comprising a mammalian C-C chemokine receptor 3 encoded by a nucleic acid which [I :\Day Lib\LI B FF] 0092 8spec.doc:gcc hybridizes under high stringency conditions with a nucleic acid selected from the group consisting of SEQ ID NO:1, SEQ ID NO:5, the complement of SEQ ID NO:1 and the complement of SEQ ID and a ligand or promotor of said receptor under conditions suitable for detecting a ligand- or promotor-induced response; and b) determining the ability of the test compound to inhibit said response, wherein inhibition of a ligand- or promotor-induced response by the compound is indicative that the compound is an inhibitor.

63. The method of claim 62, wherein a ligand selected from the group consisting of RANTES and MCP-3 is combined with said compound to be tested and said host cell. Ko 64. The method of claim 62, wherein the ligand that is combined with said compound to be tested and said host cell is eotaxin.

65. The method of claim 62, wherein the response is monitored by detecting or measuring S .chemotaxis, exocytosis or degranulation.

66. The method of any one of claims 56-65, wherein the compound to be tested is an S s5 antibody or antibody fragment.

67. The method of any one of claims 56-65, wherein the compound to be tested is an organic molecule.

68. A method of identifying an inhibitor of a mammalian C-C chemokine receptor 3 oooo comprising: 2" a) combining a compound to be tested, an isolated protein comprising a naturally occurring mammalian C-C chemokine receptor 3, and a ligand of said receptor under conditions suitable for binding of ligand to said receptor; and b) detecting or measuring the formation of a complex between said receptor and said ligand, substantially as hereinbefore described with reference to any one of the examples.

69. A method of identifying an inhibitor of a mammalian C-C chemokine receptor 3 comprising: a) combining a compound to be tested, a host cell expressing a recombinant protein comprising a naturally occurring mammalian C-C chemokine receptor 3, and a ligand of said receptor under conditions suitable for binding of ligand to said receptor; and b) detecting or measuring the formation of a complex between said receptor and said ligand, substantially as hereinbefore described with reference to any one of the examples. A method of identifying an inhibitor of a mammalian C-C chemokine receptor 3 comprising: a) combining a compound to be tested, a ligand or promoter of said receptor, and ya host cell expressing a recombinant protein comprising a naturally occurring mammalian [I:\DayLib\LIBFF]00928spec.doc:gcc 128 C-C chemokine receptor 3 under conditions suitable for detecting a ligand- or promoter-induced response; and b) determining the ability of the test compound to inhibit said response, substantially as hereinbefore described with reference to any one of the examples.

71. A method of identifying an inhibitor of a human C-C chemokine receptor 3 comprising: a) combining a compound to be tested, a ligand of a human C-C chemokine receptor 3, and an isolated protein comprising a naturally occurring human C-C chemokine receptor or (ii) a polypeptide which has at least about 80% amino acid sequence identity with SEQ ID NO:2 or SEQ ID NO:6 under conditions suitable for binding of ligand to said protein or said io polypeptide; and b) detecting or measuring the formation of a complex between said receptor or said polypeptide and said ligand, substantially as hereinbefore described with reference to any one of the examples.

72. A method of identifying an inhibitor of a human C-C chemokine receptor 3 comprising: a) combining a compound to be tested, a ligand of said receptor, and a host cell expressing a recombinant protein comprising a naturally occurring human C-C chemokine receptor or (ii) a polypeptide which has at least about 80% amino acid sequence identity with SEQ ID NO:2 or SEQ ID NO:6 under conditions suitable for binding of ligand to said receptor or said polypeptide; and 20 b) detecting or measuring the formation of a complex between said protein or said polypeptide and said ligand, substantially as hereinbefore described with reference to any one of the examples.

73. A method of identifying an inhibitor of a human C-C chemokine receptor 3 comprising: a) combining a compound to be tested, a ligand or promoter of said receptor, and a host cell expressing a recombinant protein comprising a naturally occurring human C-C chemokine receptor or (ii) a polypeptide which has at least about 80% amino acid sequence identity with SEQ ID NO:2 or SEQ ID NO:6 under conditions suitable for detecting a ligand- or promoter-induced response; and b) determining the ability of the test compound to inhibit said response, substantially as hereinbefore described with reference to any one of the examples.

74. A method of identifying an inhibitor of a human C-C chemokine receptor 3 comprising: a) combining a compound to be tested, an isolated protein comprising a naturally occurring human C-C chemokine receptor 3, and a ligand of said receptor under conditions jJ h suitable for binding of ligand to said receptor; and [I:\DayLib\LIBFF]00928spec.doc:gcc 129 b) detecting or measuring the formation of a complex between said receptor and said ligand, substantially as hereinbefore described with reference to any one of the examples. A method of identifying an inhibitor of a human C-C chemokine receptor 3 comprising: a) combining a compound to be tested, a host cell expressing a recombinant protein comprising a naturally occurring human C-C chemokine receptor 3, and a ligand of said receptor under conditions suitable for binding of ligand to said receptor; and b) detecting or measuring the formation of a complex between said receptor and said ligand, substantially as hereinbefore described with reference to any one of the examples.

76. A method of identifying an inhibitor of a human C-C chemokine receptor 3 comprising: a) combining a compound to be tested with a host cell expressing a recombinant protein comprising a naturally occurring human C-C chemokine receptor 3, and a ligand or promoter of said receptor under conditions suitable for detecting a ligand- or promoter-induced response; and b) determining the ability of the test compound to inhibit said response, 15 substantially as hereinbefore described with reference to any one of the examples.

77. A method of identifying an inhibitor of a mammalian C-C chemokine receptor 3 comprising: a) combining a compound to be tested, an isolated protein comprising a mammalian C-C chemokine receptor 3 encoded by a nucleic acid which hybridizes under high 20 stringency conditions with a nucleic acid selected from the group consisting of SEQ ID NO:1, SEQ ID NO:5, the complement of SEQ ID NO:1 and the complement of SEQ ID NO:5, and a ligand of said receptor under conditions suitable for binding of ligand to said receptor; and b) detecting or measuring the formation of a complex between said receptor and said ligand, substantially as hereinbefore described with reference to any one of the examples.

78. A method of identifying an inhibitor of a mammalian C-C chemokine receptor 3 comprising: a) combining a compound to be tested, a host cell expressing a recombinant protein comprising a mammalian C-C chemokine receptor 3 encoded by a nucleic acid which hybridizes under high stringency conditions with a nucleic acid selected from the group consisting of SEQ ID NO:1, SEQ ID NO:5, the complement of SEQ ID NO:1 and the complement of SEQ ID and a ligand of said receptor under conditions suitable for binding of ligand to said receptor; and b) detecting or measuring the formation of a complex between said receptor and said ligand, substantially as hereinbefore described with reference to any one of the examples. [I:\DayLib\LIBFF]00928spec.doc:gcc 130

79. A method of identifying an inhibitor of a mammalian C-C chemokine receptor 3 comprising: a) combining a compound to be tested, a host cell expressing a recombinant protein comprising a mammalian C-C chemokine receptor 3 encoded by a nucleic acid which hybridizes under high stringency conditions with a nucleic acid selected from the group consisting of SEQ ID NO:1, SEQ ID NO:5, the complement of SEQ ID NO:1 and the complement of SEQ ID and a ligand or promotor of said receptor under conditions suitable for detecting a ligand- or promotor-induced response; and b) determining the ability of the test compound to inhibit said response, Io substantially as hereinbefore described with reference to any one of the examples. 9*g Dated 12 October, 2000 Brigham and Women's Hospital Children's Medical Center Corporation 5 Millennium Pharmaceuticals, Inc. Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON *oo999 [I :\DayLib\LIBFF]00928spec.doc:gcc