WO1998051336A1

WO1998051336A1 - Targeted delivery to t lymphocytes

Info

Publication number: WO1998051336A1
Application number: PCT/US1998/009057
Authority: WO
Inventors: Ramesh K. Prakash; Vijay Kumar
Original assignee: Theratech, Inc.
Priority date: 1997-05-15
Filing date: 1998-05-04
Publication date: 1998-11-19
Also published as: AU7282698A; ZA983996B

Abstract

A composition for intracellular delivery of a chemical agent into a T cell comprises a receptor-binding and endocytosis-inducing ligand and a chemical agent coupled to a water soluble polymer. The ligand binds to a receptor on T lymphocytes and elicits endocytosis of the composition. The composition also includes a spacer for coupling the chemical agent and the ligand to the polymer. Chemical agents can include cytotoxins, transforming nucleic acids, gene regulators, labels, antigens, drugs, and the like. A preferred water soluble polymer is polyethyleneglycol and activated derivatives thereof. The composition can further comprise a carrier such as a water soluble polymer, liposome, or particulate. Methods of using these compositions for delivering a chemical agent in vivo or in vitro are also disclosed.

Description

TARGETED DELIVERY TO T LYMPHOCYTES

Background of the Invention This invention relates to delivery of chemical agents to cells. More particularly, this invention relates to compositions and methods for intracellular delivery of chemical agents to a specific cell type, i.e. T lymphocytes.

Toxins that target cell surface receptors or antigens on tumor cells have attracted considerable attention for treatment of cancer. E.g. , I. Pastan & D. FitzGerald, Recombinant Toxins for Cancer Treatment, 254 Science 1173 (1991); Anderson et al . , U.S. Patent Nos. 5,169,933 and 5,135,736; Thorpe et al., U.S. Patent No. 5,165,923; Jansen et al., U.S. Patent No. 4,906,469; Frankel, U.S. Patent No.

4,962,188; Uhr et al., U.S. Patent No. 4,792,447; Masuho et al., U.S. Patent Nos. 4,450,154 and 4,350,626. These agents include a cell-targeting moiety, such as a growth factor or an antigen-binding protein, linked to a plant or bacterial toxin. They kill cells by mechanisms different from conventional chemotherapy, thus potentially reducing or eliminating cross resistance to conventional chemotherapeutic agents . The membrane glycoprotein CR2, also known as

CD21, occurs on mature B lymphocytes (B cells) and certain epithelial cells, such as human pharyngeal epithelial cells, human follicular dendritic cells, and cervical epithelium, and is a receptor for both Epstein-Barr Virus (EBV) and complement fragments C3d/C3dg. N. Miller & L.M. Hutt-Fletcher, 66 J. Virol. 3409 (1990). Thymocytes, peripheral T cells, and T-cell lines have also been found to express CR2 or CR2-like molecules. CD. Tsoukas & J.D. Lambris, Expression of EBV/D3d Receptors on T Cells: Biological Significance, 14 Immunology Today 56 (1993) . The reactivities of these molecules with ligands or antibodies vary from those of B cells, however, which suggested that there are structural differences between such receptors on T-cells and B-cells. J.A. Hedrick et al . , Interaction between Epstein-Barr Virus and a T Cell Line (HSB-2) via a Receptor Phenotypically Distinct from Complement Receptor Type 2 , 22 Eur. J. Immunol. 1123 (1992). More recently, EBV was discovered to bind and infect HSB-2 T cells via a receptor distinct from CR2. J.A. Hedrick et al. , Characterization of a 70-kDa, EBC gp350/220- Binding Protein on HSB-2 T Cells, 153 J. Immunol. 4418 (1994) .

The CR2 receptor is a 145 kD membrane glycoprotein that, in addition to its binding function, is also involved in a pathway of B cell activation. E.g. , G.R. Nemerow, et al., Identification and Characterization of the Epstein- Barr Virus Receptor on Human B Lymphocytes and its Relationship to the C3d Complement Receptor (CR2) , 55 J. Virol 347 (1985) . Infection of B cells by EBV is initiated by selective binding of the gp350/220 envelope glycoprotein of the virus to the CR2 receptor, followed by intern^'alization of the CR2 receptor and endocytosis of the receptor-bound virions. E.g. , Tedder et al . (1986), Epstein-Barr Virus Binding Induces Internalization of the C3d Receptor: A Novel Immunotoxin Delivery System, 137 J. Immunol. 1387 (1986). Epithelial cells containing the CR2 receptor also bind EBV, but apparently such cells are infected by a mechanism other than receptor- mediated endocytosis. Some T-cell lines can be infected by EBV, while infection of other T-cell lines is variable or undetectable . CD. Tsoukas & J.D. Lambris, Expression of EBV/C3d Receptors on T Cells: Biological Significance, 14 Immunology Today 56 (1993) . For example, although HSB-2 T cells lack the CR2 receptor, such cells are infected by EBV. J.A. Hedrick et al . , 22 Eur. J. Immunol. 1123 (1992). Nemerow et al . , Identification of gp350 as the

Viral Glycoprotein Mediating Attachment of Epstein- Barr Virus (EBV) to the EBV/C3d Receptor of B Cells: Sequence Ho ology of gp350 and C3 Complement Fragment C3d, 61 J. Virol. 1416 (1987), have identified domains of amino acid sequence similarity between C3dg and gp350/220, including a domain near the N-terminus of gp350/220 (Glu-Asp-Pro-Gly-Phe-Phe-Asn-Val-Glu; SEQ ID NO:l) that corresponds to a sequence in C3dg (Glu-Asp- Pro-Gly-Lys-Gln-Leu-Tyr-Asn-Val-Glu; SEQ ID NO: 2). Nemerow et al . , Identification of an Epitope in the Major Envelope Protein of Epstein-Barr Virus that Mediates Viral Binding to the B Lymphocyte EBV Receptor (CR2), 56 Cell 369 (1989), have also described binding of a synthetic tetradecapeptide containing the amino acid sequence identified as SEQ ID NO:l both to the purified CR2 receptor and to CR2- expressing B cells. This synthetic peptide also blocked binding of recombinant gp350/220 or C3dg to the CR2 receptor on B cells, and a similar synthetic peptide inhibited EBV infection in vitro . Analysis of truncation and substitution peptide analogs showed that the EBV epitope involved in CR2 binding is contained within the Glu-Asp-Pro-Gly-Phe-Phe-Asn-Val- Glu sequence (SEQ ID NO:l). Reduced levels of binding were observed with shorter peptides, although a Glu-

Asp-Pro-Gly (SEQ ID NO: 3) peptide retained significant CR2 binding activity. A peptide containing a single amino acid substitution of glycine for proline within this region also exhibited significantly reduced CR2 binding activity. Copending U.S. Patent Application Serial No. 08/305,770, filed September 13, 1994, describes compositions and methods for specific intracellular delivery of a chemical agent into a CR2-receptor- bearing cell, e . g. B lymphocytes. The compositions comprise a CR2-receptor-binding and endocytosis- inducing ligand (CBEL) coupled to the chemical agent. The CBEL binds to the CR2 receptor on the surface of B lymphocytes and elicits endocytosis of the composition. Optionally, the composition can include a spacer, which can be either biodegradable or non- biodegradable, for coupling the CBEL to the chemical agent. Chemical agents can include cytotoxins, transforming nucleic acids, gene regulators, labels, antigens, drugs, and the like. The composition can further comprise a carrier such as a water soluble polymer, liposome, or particulate.

It would also be advantageous to develop compositions that are specifically targeted to other cell types. For example, targeting of T lymphocytes would enable therapeutic applications for T-cell- associated diseases and tissue graft rejection. Such T-cell-associated diseases include arthritis, T-cell lymphoma, skin cancers, and diseases resulting from HIV infection.

Copending U.S. Patent Application Serial No. 08/616,693, filed March 15, 1996, describes compositions and methods for specific intracellular delivery of a chemical agent into T lymphocytes. The compositions are represented by the formula [L-S]_a-C- [S-A]_b wherein L is a ligand configured for binding to a receptor on a T lymphocyte and stimulating receptor- mediated endocytosis of the composition, A is a chemical agent, S is a spacer moiety, C is a water soluble polymer having functional groups compatible with forming covalent bonds with the ligand, chemical agent, and spacer, a is an integer of at least 2, and b is an integer of at least 1. A preferred water soluble polymer is a copolymer of N-(2- hydroxypropyl)methacrylamide (HPMA) . Preferred chemical agents include cytotoxins, transforming nucleic acids, gene regulators, labels, antigens, drugs, and the like. The composition can further comprise a carrier such as a water soluble polymer, liposome, or particulate.

It would also be advantageous to develop additional compositions for delivery of chemical agents to T lymphocytes comprising water soluble polymers that are inexpensive, approved by the U.S. Food and Drug Administration (FDA), and resistant to eliciting an antibody response.

In view of the foregoing, it will be appreciated that compositions for intracellular delivery of chemical agents to T cells and methods of use thereof would be significant advancements in the art.

Objects and Summary of the Invention It is an object of the present invention to provide compositions for intracellular delivery of selected chemical agents to a specific cell type, i.e. T lymphocytes.

It is also an object of the invention to provide methods of making and methods of using compositions for intracellular delivery of selected chemical agents to T lymphocytes. It is another object of the invention to provide compositions and methods for intracellularly delivering selected chemical agents, such as cytotoxins, transforming nucleic acids, gene regulators, labels, antigens, drugs, and the like, to T lymphocytes .

It is still another object of the invention to provide compositions and methods for delivering selected chemical agents to T lymphocytes using water soluble polymers that are inexpensive, FDA-approved, and resistant to development of an antibody response.

These and other objects can be accomplished by providing a composition for intracellular delivery of a chemical agent capable of eliciting a selected effect when delivered intracellularly into a T lymphocyte, the composition having the formula:

[L-S]_a-C-[S-A]_b wherein L is a ligand configured for binding to a receptor on the T lymphocyte and stimulating receptor- mediated endocytosis of the composition; A is the chemical agent; S is a spacer; C is a water soluble polymer having functional groups compatible with forming covalent bonds with the ligand, chemical agent, and spacer; and a and b are integers of at least 1. A preferred water soluble polymer is selected from the group consisting of polyethylene glycol and activated derivatives thereof. The ligand is preferably a member of the group consisting of a peptide with the amino acid sequence identified as SEQ ID NO:l and peptides substantially homologous thereto, with a peptide having the amino acid sequence of SEQ ID NO:l being especially preferred. The chemical agent is preferably a member selected from the group consisting of cytotoxins, transforming nucleic acids, gene regulators, labels, antigens, and drugs. Preferably, the spacer is biodegradable such that the chemical agent is detachable from the polymer inside a cell. More preferably, the spacer comprises a peptide, and most preferably the spacer is a peptide with the amino acid sequence Gly-Phe-Leu-Gly (SEQ ID NO: 4). The composition can further comprise a carrier selected from the group consisting of water soluble polymers, liposomes, and particulates. The compositions are used in vitro by contacting populations of cells with an effective amount of composition under conditions wherein the ligand binds to a receptor on the T lymphocyte and elicits endocytosis of the receptor-bound composition. For in vivo use, an effective amount of the composition is systemically administered such that the ligand contacts and binds to receptors on T lymphocytes and then stimulates endocytosis of the composition. Once inside the cells, the chemical agent elicits its selected effect, although some agents may be active at the cell membrane.

Brief Description of the Drawings FIG. 1 shows the cytotoxic effects of ADR-PEG-NP (□) and ADR-PEG (Δ) on HSB-2 (□) , CCRF-CEM (0), and MOLT-3 (O) T cells.

FIG. 2 shows the respective cytotoxic effects of ADR-PEG-NP (□) and ADR-PEG (Δ) on Raji B cells.

Detailed Description of the Invention Before the present compositions and methods for targeted delivery to T lymphocytes are disclosed and described, it is to be understood that this invention is not limited to the particular embodiments, process steps, and materials disclosed herein as such embodiments, process steps, and materials may vary somewhat. It is also to be understood that the terminology used herein is used for the purpose of describing particular embodiments only and is not intended to be limiting since the scope of the present invention will be limited only by the appended claims and equivalents thereof.

It must be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a composition containing "a ligand" includes reference to two or more ligands, reference to "a chemical agent" includes reference to one or more of such chemical agents that may be the same or different chemical agents, and reference to "a spacer" includes reference to two or more spacers.

In describing and claiming the present invention, the following terminology will be used in accordance with the definitions set out below.

As used herein, "peptide" means peptides of any length and includes proteins. The terms "polypeptide" and "oligopeptide" are used herein without any particular intended size limitation, unless a particular size is otherwise stated.

As used herein, "ligand" means a composition capable of binding to a receptor on a T lymphocyte and stimulating internalization by endocytosis of the receptor and receptor-bound ligand. According to the present invention, ligands are coupled to various functional molecules so that upon endocytosis of the ligands the various functional molecules coupled thereto are also internalized by the T cells.

Preferred ligands for binding to a receptor on a T lymphocyte and inducing internalization by endocytosis of the receptor and receptor-bound ligand are a peptide having the amino acid sequence identified as SEQ ID NO:l and peptides substantially homologous thereto. As used herein, "substantially homologous" means peptides that retain functionality in binding T-cell receptors and eliciting receptor- mediated endocytosis although they may be truncations, deletion variants, or substitution variants of SEQ ID N0:1 or include additional amino acid residues attached thereto. Substitution variants are those that contain a conservative substitution of one or more amino acid residues. A conservative substitution is a substitution of one amino acid residue for another wherein functionality of the peptide is preserved, in this case, functionality in binding a T- cell receptor and eliciting endocytosis of the receptor-bound composition. Amino acid residues belonging to certain conservative substitution groups can sometimes substitute for another amino acid residue in the same group. One classification of such conservative substitution groups is as follows: (a) Pro; (b) Ala, Gly; (c) Ser, Thr; (d) Asn, Gin; (e) Asp, Glu; (f) His; (g) Lys, Arg; (h) Cys; (i) lie, Leu, Met, Val; and (j) Phe, Trp, Tyr . M. Jimenez- Montano & L. Zamora-Cortina, Evolutionary model for the generation of amino acid sequences and its application to the study of mammal alpha-hemoglobin chains, Proc. Vllth Int ' 1 Biophysics Congress, Mexico City (1981) . Another classification of such groups is described in M. Dayhoff et al . , Atlas of Protein

Sequence and Structure (Nat'l Biomed. Res. Found., Washington, D.C, 1978), hereby incorporated by reference. Other variations that are to be considered substantially homologous include substitution of D- amino acids for the naturally occurring L-amino acids, substitution of amino acid derivatives such as those containing additional side chains, and substitution of non-standard amino acids, i.e. α-amino acids that are rare or do not occur in proteins. Thus, the primary structure of a ligand is limited only by functionality.

It was unexpected and surprising to discover that a composition having a ligand comprising a peptide with an amino acid sequence of SEQ ID NO:l and peptides substantially homologous thereto are preferentially targeted to T cells rather than to B cells. This result is surprising because in copending U.S. Patent Application Serial No. 08/305,770, filed September 13, 1994, compositions comprising a CR2- receptor-binding and endocytosis-inducing ligand (CBEL), i.e. SEQ ID NO:l, coupled to a chemical agent, i.e. ricin A, were specifically delivered intracellularly into B cells, but not T cells. Without being limited to any particular theory of operation, it appears that coupling the ligand to a spacer peptide, e.g. a peptide having the sequence of SEQ ID NO: 4, modifies the specificity of the ligand such that the composition binds preferentially to T cells and is delivered intracellularly into such T cells. The use of multiple ligand molecules bound to the water soluble polymer may also affect cell specificity. Binding and uptake of the composition by T cells may be mediated by the EBV receptor described by J.A. Hedrick et al . , supra . In in vitro experiments, a fraction of B cells exposed to this composition also binds and takes up the composition, but in vivo the composition appears to be taken up by T cells, and not at all or only slightly by B cells. As used herein, "macromolecule" means a composition comprising a water soluble polymer with a ligand and a chemical agent bound thereto. Preferably the polymer is polyethylene glycol (PEG) and the ligand is an oligopeptide . The chemical agent can be from many different classes of molecules, as explained in more detail herein.

As used herein, "prodrug" means a chemical agent that is chemically modified to overcome a biological barrier. When a chemical agent is converted into its prodrug form, its biological activity is eliminated or substantially reduced, but the biological barrier that inhibited its effectiveness is no longer problematic. The chemical group that is attached to the chemical agent to form the prodrug, i.e. the "pro-moiety", is removed from the prodrug by enzymatic or nonenzymatic means to release the active form of the chemical agent. See A. Albert, Chemical Aspects of Selective Toxicitv, 182 Nature 421 (1958) . The instant compositions are prodrugs because the chemical agent that has the selected effect when internalized in T lymphocytes is modified with a ligand, water soluble polymer, and spacers such that the composition is delivered into the T lymphocytes, thus penetrating the cell membrane thereof. The biological effect of the chemical agent is greatly reduced or eliminated until the composition is delivered intracellularly and the chemical agent is released from the remainder of the composition by biodegradation of the spacer. As used herein, "chemical agent" means and includes any substance that has a selected effect when internalized into a T lymphocyte. Certain chemical agents have a physiological effect, such as a cytotoxic effect or an effect on gene regulation, on a T cell when internalized into the cell . A

"transforming nucleic acid" (RNA or DNA) , when internalized into a cell, can be replicated and/or expressed within the cell. Other nucleic acids can interact with regulatory sequences or regulatory factors within the cell to influence gene expression within the cell in a selected manner. A detectable label delivered intracellularly can permit identification of cells that have internalized the compositions of the present invention by detection of the label. Drugs or pharmacologically active compounds can be used to ameliorate pathogenic effects or other types of disorders. Particularly useful chemical agents include polypeptides, and some such chemical agents are active fragments of biologically active proteins, or are specific antigenic fragments

(e.g., epitopes) of antigenic proteins. Thus, chemical agents include cytotoxins, gene regulators, transforming nucleic acids, labels, antigens, drugs, and the like. As used herein, "drug" or "pharmacologically active agent" means any chemical material or compound suitable for intracellular administration in a T lymphocyte that stimulates a desired biological or pharmacological effect in such cell. As used herein, "carrier" means water soluble polymers, particulates, or liposomes to which a composition according to the instant invention can be coupled. Such carriers increase the molecular size of the compositions and may provide added selectivity and/or stability. Such selectivity arises because carrier-containing compositions are too large to enter cells by passive diffusion, and thus are limited to entering cells through receptor-mediated endocytosis. The potential for use of such carriers for targeted drug delivery has been established. See, e.g., J.

Kopecek, 5 Bio aterials 19 (1984); E. Schacht et al . , Polysaccharides as Drug Carriers, in Controlled- Release Technology 188 (P.I. Lee & W.R. Good, eds . , 1987); F. Hudecz et al., Carrier design: Cytotoxicity and Im unogenicity of Synthetic Branched Polypeptides with Poly (L-lysine) Backbone, 19 J. Controlled Release 231 (1992); Z. Brich et al., Preparation and Characterization of a Water Soluble Dextran Immunocon ugate of Doxorubicin and the Monoclonal Antibody (ABL364). 19 J. Controlled Release 245

(1992) . Thus, illustrative water soluble polymers include dextran, inulin, poly (L-lysine) with modified epsilon amino groups, poly (L-glutamic acid), N- substituted methacrylamide-containing synthetic polymers and copolymers, and the like.

As used herein, "effective amount" is an amount that produces a selected effect. For example, a selected effect of a composition containing a cytotoxin as the chemical agent could be to kill a selected proportion of T cells within a selected time period. An effective amount of the composition would be the amount that achieves this selected result, and such an amount could be determined as a matter of routine by a person skilled in the art. The compositions of the present invention provide intracellular delivery of a chemical agent capable of eliciting a selected effect when delivered intracellularly into a T lymphocyte, the composition having the formula: [L-S]_a-C-[S-A]_b wherein L is a ligand capable of binding to a receptor on the T lymphocyte and stimulating receptor-mediated endocytosis of the composition; A is the chemical agent; S is a spacer; C is a water soluble polymer having functional groups compatible with forming covalent bonds with the ligand, chemical agent, and spacer; and a and b are integers of at least 1. Preferably, a and b are integers of 1 to about 1000. The spacers are preferably biodegradable such that the chemical agent is detached from the composition by hydrolysis and/or enzymatic cleavage inside T cells. CD4⁺ T cells are targeted by these compositions, but it remains to be determined whether CD8⁺ T cells are also targeted. The chemical agent is selected from the group consisting of cytotoxins, transforming nucleic acids, gene regulators, labels, antigens, drugs, and the like. The water soluble polymer (represented by C in the formula above) is preferably polyethyleneglycol or an activated derivative thereof (PEG) . PEG is preferred because it is inexpensive, approved by the FDA for administration to humans, and is resistant to eliciting an antibody response. The coupling of a ligand to a chemical agent can be, without limitation, by covalent bond, electrostatic interaction, hydrophobic interaction, physical encapsulation, and the like. The compositions of the present invention can further comprise a carrier selected from the group consisting of water soluble polymers, liposomes, and particulates . Such water soluble polymers for use as carriers are selected from the group consisting of dextran, inulin, poly (L-lysine) (PLL) with modified epsilon amino groups, poly (L-glutamic acid) (PGA), N- substituted methacrylamide-containing polymers and copolymers, and the like. A preferred water soluble polymer is a copolymer of N-(2- hydroxypropyl)methacrylamide (HPMA) .

Thus, according to the invention, the composition provides means for preferential binding to a receptor on T cells, thus triggering internalization of the composition by endocytosis. The chemical agent provides means for achieving a selected effect in the T cells. Accordingly, for example, chemical agents comprise cytotoxins, including radionuclides, for selective killing or disabling of T cells; nucleic acids for genetically transforming or regulating gene expression in T cells; drugs or other pharmacologically active agents for achieving a selected therapeutic effect; labels, including fluorescent, radioactive, and magnetic labels, for permitting detection of cells that have taken up the compositions; and the like.

In some embodiments, the compositions are constructed by chemically conjugating the ligand and chemical agent to the water soluble polymer. "Chemically conjugating" the ligand and the chemical agent to the water soluble polymer, as that term is used herein, means covalently bonding the ligand and chemical agent to the polymer by way of a spacer moiety. In particular embodiments, a spacer moiety is used to form a linkage between functional groups on the polymer and the chemical agent.

Peptide portions of the compositions of the present invention can be produced in a genetically engineered organism, such as E. coli, as a "fusion protein." That is, a hybrid gene containing a sequence of nucleotides encoding a ligand, spacer, or peptide chemical agent can be constructed by recombinant DNA technology. This hybrid gene can be inserted into an organism such that the "fusion protein" encoded by the hybrid gene is expressed. The fusion protein can then be purified by standard methods, including affinity chromatography . Peptides containing a ligand, spacer, or peptide chemical agent can also be constructed by chemical synthesis. Short peptide ligands are generally preferred, both because short peptides can be manipulated more readily and because the presence of additional amino acids residues, and particularly of substantial numbers of additional amino acids residues, may interfere with the function of the peptide ligand in stimulating internalization of the chemical agent by endocytosis. Compositions according to the present invention preferably also further include a protease digestion site situated so that once the composition is within the cell, the chemical agent can be separated from the remainder of the composition by proteolysis of the digestion site. Such a protease susceptible spacer can be added regardless of whether the peptide portions of the composition are synthesized chemically or as expression peptides in a genetically engineered organism. In the latter case, nucleotides encoding the protease susceptible spacer can be inserted into the hybrid gene encoding the ligand and or a peptide chemical agent by techniques well known in the art.

Another aspect of the present invention features a method for specifically effecting a desired activity in T lymphocytes contained in a heterogeneous population of cells, by steps of contacting the population of cells with a composition, prepared according to the present invention, that directs such activity intracellularly. The compositions of the invention are selectively bound to T cells in the mixed population, whereupon endocytosis of the composition into the T cells is stimulated, and the chemical agent effects its activity within such T cells.

This application employs, except where otherwise indicated, standard techniques for manipulation of peptides and for manipulation of nucleic acids for expression of peptides. Techniques for conjugation of oligopeptides and oligonucleotides are known in the art, and are described for example in T. Zhu et al . , 3 Antisense Res. Dev. 265 (1993); T. Zhu et al., 89 Proc. Nat'l Acad. Sci . USA 7934 (1992); P. Rigaudy et al., 49 Cancer Res. 1836 (1989), which are hereby incorporated by reference.

As is noted above, the invention features peptides, employed as ligands, spacers, and/or chemical agents. The peptides according to the invention can be made by any of a variety of techniques, including organic synthesis and recombinant DNA methods. Techniques for chemical synthesis of peptides are described, for example, in B. Merrifield et al . , 21 Biochemistry 5020 (1982);

Houghten, 82 Proc. Nat ' 1 Acad. Sci. USA 5131 (1985); M. Bodanszky & A. Bodanszky, The Practice of Peptide Synthesis (Springer-Verlag 2d ed., 1994), incorporated herein by reference. Techniques for chemical conjugation of peptides with other molecules are known in the art.

A fusion protein according to the invention can be made by expression in a suitable host cell of a nucleic acid containing an oligonucleotide encoding a ligand and/or spacer, or a chemical agent and/or spacer. Such techniques for producing recombinant fusion proteins are well-known in the art, and are described generally in, e.g., J. Sambrook et al., Molecular Cloning: A Laboratory Manual (2d ed., 1989), the pertinent parts of which are hereby incorporated herein by reference. Reagents useful in applying such techniques, such as restriction endonucleases and the like, are widely known in the art and commercially available from any of several vendors. Construction of compositions according to the present invention will now be described, with particular reference to examples in which a peptide ligand coupled to a biodegradable spacer (SEQ ID NO: 4) and a cytotoxic chemical agent, adriamycin, are coupled to PEG. In Examples 1-6, a composition according to the present invention was prepared by coupling an EBV- derived ligand (SEQ ID N0:1) and/or the cytotoxic chemical agent, adriamycin, to PEG via a protease- sensitive spacer (Gly-Phe-Leu-Gly; SEQ ID N0:4). Adriamycin intercalates with DNA and inhibits DNA replication, thus exerting a toxic effect on cells. Compositions according to this example are lysosomotropic, and the degree of cytotoxicity depends on the biodegradability of the drug-polymer linkage within the lysosomes . The protease-sensitive spacer, Gly-Phe-Leu-Gly (SEQ ID NO: 4) is biodegradable in lysosomes, but is resistant to proteolysis in the bloodstream. The construction of these compositions is described in detail below.

Example 1 NH₂-Gly-Phe-OH (Sigma Chemical Co. St. Louis, MO; 0.63 g, 2.84 mmol) was dissolved in 20 ml of phosphate-buffered saline (PBS) containing 0.5 M NaCl . The reaction mixture was stirred and 1000 mg (0.92 mmol of active pendent groups) of solid activated PEG (succinimidyl ester of 5 pendent polyethyleneglycol propionic acid; p-5-SPA-5000; Shearwater Polymers, Inc., Huntsville, AL) was added to the solution. The reaction was continued for 4.5 hours at pH 7-8. The solution was then dialyzed against PBS (500 ml) three times at 4°C for a total of 39.5 hours. Water was partially removed from the solution by dialysis using PEG (M.W. = 20,000,000) on the dialyzed tube. The concentrated solution (about 14 ml) was extracted four times with 100 ml each of dichloromethane (A.C.S., HPLC grade, Sigma or Aldrich) . An emulsion was formed during extraction and was partially broken by adding NaCl in the emulsion. The organic layers were pooled and dried over MgS0₄ overnight. The solution was filtered, and the filtrate was concentrated by evaporating the dichloromethane with a rotary evaporator at about 35°C using a water pump. The final volume of solution was reduced to about 10 ml. The solution was added to ether (250 ml; anhydrous, Fisher) , and the product, PEG-Gly-Phe-OH, was precipitated. The precipitates were filtered, washed with ether, and dried in air. The yield was 0.70 g.

Example 2

PEG-Gly-Phe-OH (614 mg, 0.51 mmol), prepared according to the procedure of Example 1, and Leu-Gly- 0^tBu (Bachem Biosciences, Inc., King of Prussia, PA; 358.5 mg, 1.47 mmol) were dissolved in dichloromethane (6 ml) followed by the addition of solid dicyclohexylcarbodiimide (DCC; Sigma; 152 mg, 0.74 mmol) at room temperature under a nitrogen atmosphere. A precipitate of N, N' -dicyclohexylurea started to separate slowly, and its amount gradually increased. The reaction was continued for 5.5 hours. The urea derivative was removed by filtration and washed with dichloromethane. The solvent was evaporated from the solution with a rotary evaporator at about 35°C using a water pump until the volume of the solution was about 5 ml. The concentrated solution was slowly added to ether (250 ml) with stirring. The product, PEG-Gly-Phe-Leu-Gly-O^tBu was precipitated, filtered, washed with ether, and dried. The yield was 0.56 g.

Example 3 The compound PEG-Gly-Phe-Leu-Gly-O'Bu (0.56 g,

0.38 mmol), prepared according to the procedure of Example 2, was dissolved in trifluoroacetic acid (20 ml; TFA, J.T. Baker) and left to stand at room temperature with stirring for 2 hours. The solution was evaporated to dryness in a rotary evaporator at about 45°C using a water pump. The residue was dissolved in dichloromethane (3 ml) and added to ether (200 ml) . The product, PEG-Gly-Phe-Leu-Gly-OH, was isolated by filtering the precipitates, washing them with ether, and drying in air. The yield was 0.34 g.

Example 4 A solution of PEG-Gly-Phe-Leu-Gly-OH (0.32 g, 0.23 mmol), prepared according the procedure of

Example 3, p-nitrophenol (Fluka; 0.05 g, 0.38 mmol), ethylacetate (Aldrich, Milwaukee, WI; 8 ml), and tetrahydrofuran (anhydrous, Aldrich; 5 ml) was stirred with a magnetic stirrer in an ice water bath under a nitrogen atmosphere. DCC (0.08 g, 0.39 mmol) was added to the reaction mixture in one aliquot. The reaction solution was kept at the ice bath temperature (about 4°C) for 30 minutes with stirring. The temperature of the reaction solution was then raised to room temperature, and the reaction was then continued for another 4 hours. Ethyl acetate (35 ml) was added to the solution, which was slightly warmed and then filtered. The filtrate was concentrated by evaporating the solvent with a rotary evaporator using a water pump. The clear concentrated solution (4 ml) was added to ether (175 ml) . The precipitate was filtered, washed with ether, and dried in air. The yield was 0.24 g. The product, PEG-Gly-Phe-Leu-Gly- ONp, was dissolved in 0.1 N NaOH, and the liberated p- nitrophenol concentration was estimated by spectrophotometry at 400 nm using a molar extinction coefficient of e = 1.8 x 10⁴ 1/mol-cm. The product was determined to have an ONp content of 65 μmol/g, which was far less than the theoretical value of 644.6 μmol/g. This demonstrated that the reaction was incomplete, and thus it was determined to perform the reaction again.

The product of the reaction (0.22 g) was again reacted according to the procedure described above, but using extra amounts of p-nitrophenol (0.07 g, 0.51 mmol) and DCC (0.09 g, o.44 mmol). The solvents used for the reaction were ethylacetate (5 ml) and tetrahydrofuran (5 ml) . The reaction was performed for half an hour at about 4°C and for 31.5 hours at room temperature. The yield of the compound was 0.15 g. The final product showed an ONp content of 129.5 μmol/g. This increase of ONp content demonstrated that the ONp content could be increased by resynthesizing the product.

Example 5 PEG-Gly-Phe-Leu-Gly-ONp (77.1 mg, ONp content = 9.99 μmol), prepared according to the procedure of Example 4, was dissolved in 1000 μl anhydrous dimethylformamide (DMF) and adriamycin hydrochloride (Sigma; 2.28 mg, 3.93 μmol) was added. Triethylamine diluted 1:2 with DMF (6 μl, 14.3 μmol triethylamine) was added to the reaction mixture, and the solution was stirred for 12 hours at room temperature. DL-1- amino-2-propanol (Aldrich) diluted 1:10 with DMF was added (10 μl) to aminolyze the unreacted ONp groups in the product. The reaction solution was added to ether (100 ml), and the conjugate precipitates (PEG-Gly-Phe- Leu-Gly-Adriamycin; hereinafter, "ADR-PEG") were filtered, washed with ether, and dried. The yield of the conjugate was 46.2 mg. Adriamycin content in the conjugate was determined spectrophotometrically at 488 nm in water (using e = 1.0 x 10⁴ 1/mol-cm) as 2.8% (w/w) . Example 6 PEG-Gly-Phe-Leu-Gly-ONp (71.15 mg, ONp content 9.2 μmol), prepared according to the procedure of Example 4, was dissolved in 1000 μl anhydrous DMF. Adriamycin hydrochloride (2.1 mg, 3.62 μmol) and a nonapeptide ligand (SEQ ID NO:l; 8.82 mg, 8.38 μmol; Peptide International, Kentucky, Arkansas) were added to the PEG-Gly-Phe-Leu-Gly-ONp solution. Triethylamine diluted 1:2 with DMF (6 μl, 14.3 μmol triethylamine) was added to the reaction mixture three times in an interval of 10 minutes, and the solution was stirred for 14 hours at room temperature. DL-1- amino-2-propanol dilute 1:10 with DMF (10 μl) was added to aminolyze unreacted ONp groups . The reaction solution was added to ether (100 ml), and the conjugate precipitates were filtered, washed with ether, and dried. The yield of the conjugate was 35.5 mg. Adriamycin content was determined according to the procedure of Example 5 to be 2.01% (w/w) . Nonapeptide concentration was determined to be 7.62%

(w/w) or 72.36 μmol/g by hydrolyzing an aliquot of the conjugate with 6 N HC1 at 105°C and quantitatively analyzing with reverse phase HPLC The conjugate has the structure PEG-Gly-Phe-Leu-Gly-Glu-Asp-Pro-Gly-Phe- Phe-Asn-Val-Glu-Adriamycin (SEQ ID NO: 5; hereinafter, "ADR-PEG-NP") .

Example 7 The in vitro effects of ADR-PEG and ADR-PEG-NP prepared according to the procedures of Examples 5 and 6, respectively, were tested on several human T and B cell lines as follows. Triplicate samples of 1 x 10⁵ cells each were mixed with different concentrations of the purified compositions in 0.1 ml of culture medium (RPMI 1640, 10% fetal calf serum) in the wells of a 96-well microtiter plate (Falcon Microtest 111) , and incubated for 18-48 hours at 37°C in a humidified, 5% C0₂ atmosphere. Thereafter, cell viability was assessed by a colorimetric method using the tetrazolium compound MTS (3- (4, 5-dimethylthiazol-2- yl) -5- (3-carboxymethoxyphenyl) -2- (4-sulfophenyl) -2H- tetrazolium, inner salt) and an electron coupling reagent, PMS (phenazine methosulfate) . MTS is bioreduced by living cells into a soluble formazan product. The absorbance of the formazan at 490 nm can be measured directly from 96 well assay plates without additional processing. The quantity of formazan product as measured by the absorbance at 490 nm is directly proportional to the number of living cells in culture. Reagents for the MTS assay were obtained from Promega Corp. (Madison, Wisconsin) . According to this method, 20 μl of MTS/PMS solution (Promega No. G- 5421) was added to each well of the assay plate. The plate was then further incubated at 37°C in a humidified, 5% C0₂ atmosphere for 4 hours. The absorbance of each well was then measured at 490 nm with an EL311 Microplate Autoreader (Bio-Tek Instruments) . The mean absorbance for each treatment was then calculated, and the percent cytotoxicity was determined using the formula:

A_s

% cytotoxity = (1-—) x 100

^Ac

wherein A_s represents the mean absorbance for each treatment and A_c represents mean absorbance of the control treatment, i.e. cells not exposed to a conjugate . The following cell lines were tested according to this procedure: HSB-2 (ATCC No. CCL 120.1; CD4⁺ human T cells); CCRF-CEM (ATCC No. CCL 119; CD4⁺ human T cells); MOLT-3 (ATCC No. CRL 1552; CD4⁺ human T cells); and Raji (ATCC No. CCL 86; CR2⁺ human B lymphoblastoid cells) . FIG. 1 shows the cytotoxic effects of ADR-PEG-NP on HSB-2 (□) , CCRF-CEM (0), and MOLT-3 (O) cells. For example, at 100 ng/ml, based on the adriamycin concentration of the conjugate, ADR-PEG-NP kills about 90% of the HSB-2 and MOLT-3 cells, but only about 15% of the CCRF-CEM cells. At the same concentration (100 ng/ml) of ADR-PEG, only about 15% of HSB-2 cells were killed (not shown) . Thus, the ADR-PEG-NP conjugate is much more toxic to HSB-2 and MOLT-3 cells than is the control ADR-PEG conjugate, and the ADR-PEG-NP is also much more toxic to HSB-2 and MOLT-3 cells than to CCRF-CEM cells. At higher concentrations of conjugate, even the control ADR-PEG conjugate exhibits high cytotoxicity, but this effect is attributed to non-specific uptake of the conjugate. FIG. 2 shows the respective cytotoxic effects of

ADR-PEG-NP (□) and ADR-PEG (Δ) on Raji B cells. These results show some cytotoxicity in the ADR-PEG-NP- treated cells, but the cytotoxic effect achieved is never as great as in T cells.

The compositions according to the present invention can be employed for targeted delivery of a chemical agent to T cells, generally by contacting the T cells with the composition under conditions in which binding of the ligand to a receptor stimulates endocytosis of the composition into the T cells. The chemical agent then acts on or within the targeted cell into which the composition is internalized, and the desired effect of the active agent can be confined to those cells having the receptor.

For example, a composition according to the invention can be employed as an effective antitumor agent in vivo for killing T cells. Preferably, the composition is administered to the subject by systemic administration, typically by subcutaneous, intramuscular, or intravenous injection, or intraperitoneal administration, which are methods well known in the art. Injectables for such use can be prepared in conventional forms, either as a liquid solution or suspension or in a solid form suitable for preparation as a solution or suspension in a liquid prior to injection, or as an emulsion. Suitable excipients include, for example, water, saline, dextrose, glycerol, ethanol, and the like; and if desired, minor amounts of auxiliary substances such as wetting or emulsifying agents, buffers, and the like may be added. The composition can be contacted with the cells in vitro or in vivo . The T cells constitute a subpopulation of a mixed population of cell types; the ligand according to the invention can provide for endocytosis of the conjugate into T cells and possibly into a small proportion of other cells having a closely related receptor.

The chemical agent can have any of a variety of desired effects in the targeted cells. As mentioned above, in some particularly useful embodiments the chemical agent is effective on a cell only when, or principally when, the agent is internalized into the cell. Example 8 In Vivo Targeted Delivery to T cells

Compositions according to the present invention can be administered to a warm-blooded animal for targeted delivery to T cells. Particularly, the composition provides for receptor-mediated internalization of the composition into the T cells.

About 1 x 10⁷ HSB-2 human T-cell leukemia cells in 500 μl of PBS were injected intraperitoneally into mice, and the cells were allowed to colonize the mice for 24 hours. The human T-cell leukemia cells were found to preferentially colonize the spleen and liver. After 24 hours, the mice were injected intraperitoneally with 150 μg of either ADR-PEG-NP or control composition ADR-PEG in 150 μl of PBS. By 55 days after injection, all of the animals injected with the control composition, ADR-PEG, had died from uncontrolled growth of the T-cell leukemia cells, whereas all of the animals injected with ADR-PEG-NP were still alive. These results show that a composition according to the present invention, wherein the chemical agent is a cytotoxin, preferentially was taken up by T cells and such T cells were killed by the cytotoxin.

Example 9

In this example, mice injected with HSB-2 T-cell leukemia cells and with either ADR-PEG or ADR-PEG-NP according to the procedure of Example 8 are tested to determine whether the liver and spleen of such animals contain human cells. The spleen and liver are harvested upon death of the control animals or at day 120 post-inoculation of the animals injected with ADR- PEG-NP, and PCR assay of genomic DNA and cDNA prepared from these organs is used to detect the presence of human cells therein.

Genomic DNA and cDNA are prepared from mouse spleen and liver according to methods that are generally well known in the art. See, e.g., J. Sambrook et al . , Molecular Cloning: A Laboratory Manual (2d ed. , 1989); T. Maniatis et al . , Molecular Cloning: A Laboratory Manual (1982) ; F. Ausubel et al., Current Protocols in Molecular Biology (1987). Illustrative methods for preparation of cDNA and genomic DNA are briefly described below.

Preparation of cDNA

The excised spleen and liver are disrupted and the resulting cells are washed in PBS. The cells are then resuspended in a buffer containing 100 mM NaCl, 10 mM Tris-HCl, pH 8.0, 25 mM EDTA, 0.5% SDS, and 0.1 mg/ml proteinase K and incubated overnight at 37°C The disrupted cells are then centrifuged and washed once in cold PBS. The cell pellet is then resuspended in RNAzol B reagent (Tel-Test, Friendwood, Texas) . The resulting lysate is then extracted with chloroform, and RNA is precipitated with isopropanol. The RNA is washed with 75% ethanol, dried briefly, and dissolved in 0.5% SDS. An aliquot of RNA is then mixed with reverse transcriptase, random primers, buffer, and deoxynucleotide triphosphates, and the mixture is incubated at 37 °C for 1 hour. The reaction is stopped by RNase digestion, and then the cDNA is extracted in succession with phenol/chloroform and chloroform, precipitated with ethanol, and resuspended in water. Preparation of Genomic DNA

Cells that are disrupted, washed, and incubated overnight in digestion buffer as described above are twice extracted with phenol/chloroform/isoamylalcohol . The DNA in the aqueous phase is then precipitated with ethanol, washed, dried, and resuspended in a buffer containing 10 mM Tris-HCl, pH 8.0, 1 mM EDTA.

PCR of cDNA and Genomic DNA

PCR is well known in the art for determining the presence of selected sequences in genomic DNA and cDNA samples. The following references illustrate PCR methodology: PCR Technology: Principles and Applications for DNA Amplification (H. Erlich ed., Stockton Press, New York, 1989); PCR Protocols: A Guide to Methods and Applications (Innis et al. eds, Academic Press, San Diego, Calif., 1990); U.S. Patent Nos. 4,683,195; 4,683,202; 4,800,159; 4,965,188. Briefly, PCR reactions are carried out in glass capillary tubes in 10 μl volumes containing 0.8 mM of each of the four deoxynucleotide triphosphates, 0.72 units of Thermus aguaticus (Taq) DNA polymerase, 35-70 pmol of each primer (20-23 nucleotides in length) , 200 ng cDNA, and a reaction buffer containing 50 mM Tris-HCl, pH 8.3, 3 mM MgCl₂, 20 mM KC1, and 0.5 mg/ml of bovine serum albumin. The amount of cDNA and number of cycles of amplification can be determined empirically by a person of ordinary skill in the art without undue experimentation. Titration of cDNA from about 1 ng to about 500 μg, and titration of cycles from about 12 to about 36 gives a good indication of amounts of cDNA and numbers of cycles needed. For example, using β-actin primers, 12-15 cycles and about 200 ng of cDNA generally give good results. The reaction mixtures are sealed in capillary tubes and then the capillaries are placed in a Model 1605 Air Thermocycler (Idaho Technology, Idaho Falls, Idaho) . Parameters of annealing temperature, elongation time, and number of cycles are selected. Increasing the annealing temperature increases the specificity of PCR amplification reactions and decreases the amounts of nonspecific products. Annealing temperature can be estimated from thermal melting temperature according to the formula:

T_ra = 4°C(no. of G and C residues in primer) + 2°C(no. of A and T residues in primer) . A person of ordinary skill in the art can optimize the annealing temperature according to known principles. The elongation time depends on the size of product to be amplified. As a rule of thumb, about 4 seconds is sufficient for products of about 100-150 bp, about 8 seconds is sufficient for products of about 200-300 bp, and about 20 seconds is needed for products larger than about 500 bp. Increasing elongation times may result in amplification of nonspecific products.

After amplification, the reaction mixture is removed from the capillary, mixed with an equal volume of stop solution (95% forma ide, 20 mM EDTA, 0.05% bromphenol blue, 0.05% xylene cyanol FF) , and either stored frozen or immediately heated at 95°C for 5 minutes and subjected to agarose gel electrophoresis . The fractionated products are then detected by ethidium bromide staining. An illustrative method of determining the relative amounts of human and mouse cells in spleen and liver tissues involves comparison of amplified products from reactions with mouse β-actin and human β-actin specific primers. Illustrative mouse β-actin primers are as follows: GTAACAATGC CATGTTCAAT (SEQ ID NO: 6)

CTCCATCGTG GGCCGCTCTA G (SEQ ID NO : 7 ) Illustrative human β-actin primers are as follows: CTTAGTTGCG TTACACCCTT TC (SEQ ID NO: 8) GGGCCATTCT CCTTAGAGAG AAG (SEQ ID NO: 9)

The results of this experiment show that all of the mice treated with the control ADR-PEG exhibit the presence of both human and mouse DNA by PCR analysis with specific β-actin primers. However, only a fraction of mice treated with ADR-PEG-NP exhibit the presence of human DNA. These results demonstrate that a ligand and adriamycin-containing composition according to the present invention selectively kills T cells in animals to which it is administered.

Example 10

A method of treating T cell lymphoma in a human comprises (a) providing a composition according to the present invention including a ligand, such as the EBV ligand (SEQ ID NO:l) or a peptide substantially homologous thereto, and a cytotoxin, such as adriamycin, both of which are coupled to water soluble polymer, such as PEG, by means of a spacer (Gly-Phe- Leu-Gly; SEQ ID NO: 4) and (b) systemically administering an effective amount of the composition to an individual. Such composition can be made, for example, as shown above in Examples 1-6. An effective amount of the composition is systemically administered to the individual such that the composition enters the bloodstream and contacts T cells. ^' The composition binds to a receptor on the T cells and stimulates internalization of the composition by endocytosis. The biodegradable spacer is digested by intracellular proteases, releasing the adriamycin. The adriamycin then kills the cell by intercalating with DNA in the cell. This procedure reduces the number of malignant T cells in the body of the individual, thereby having a positive effect in treatment of the disease.

Sequence Listing

(1) GENERAL INFORMATION:

(i) APPLICANT: Prakash, Ramesh K.

Kumar, Vijay (ii) TITLE OF INVENTION: TARGETED DELIVERY TO T

LYMPHOCYTES

(iii) NUMBER OF SEQUENCES: 9

(iv) CORRESPONDENCE ADDRESS:

(A) ADDRESSEE: Thorpe, North & Western, L.L.P.

(B) STREET: 8180 South 700 East, Suite 200

(C) CITY: Sandy

(D) STATE: Utah

(E) COUNTRY: USA (F) ZIP: 84070

(v) COMPUTER READABLE FORM:

(A) MEDIUM TYPE: Diskette, 3.5 inch, 1.44

Mb storage

(B) COMPUTER: Toshiba Satellite Pro T2150CDS (C) OPERATING SYSTEM: Windows 95

(D) SOFTWARE: Word Perfect 7.0

(vi) CURRENT APPLICATION DATA:

(A) APPLICATION NUMBER:

(B) FILING DATE: (C) CLASSIFICATION:

(vii) PRIOR APPLICATION DATA:

(A) APPLICATION NUMBER:

(B) FILING DATE:

(viii) ATTORNEY/AGENT INFORMATION: (A) NAME: Alan J. Howarth

(B) REGISTRATION NUMBER: 36,553

(C) REFERENCE/DOCKET NUMBER: T4996

(ix) TELECOMMUNICATION INFORMATION:

(A) TELEPHONE: (801)566-6633 (B) TELEFAX: (801)566-0750

(2) INFORMATION FOR SEQ ID NO:l: (i) SEQUENCE CHARACTERISTICS:

(A) LENGTH: 9 amino acids

(B) TYPE: amino acid (D) TOPOLOGY: linear

(ii) MOLECULE TYPE: peptide

(xi) SEQUENCE DESCRIPTION: SEQ ID NO:l

Glu Asp Pro Gly Phe Phe Asn Val Glu

1 5

(2) INFORMATION FOR SEQ ID NO: 2: (i) SEQUENCE CHARACTERISTICS:

(A) LENGTH: 11 amino acids

(B) TYPE: amino acid (D) TOPOLOGY: linear

(ii) MOLECULE TYPE: peptide

(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 2:

Glu Asp Pro Gly Lys Asn Leu Tyr Asn Val Glu 1 5 10

(2) INFORMATION FOR SEQ ID NO: 3:

(i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 4 amino acids

(B) TYPE: amino acid (D) TOPOLOGY: linear

(ii) MOLECULE TYPE: peptide

(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 3: Glu Asp Pro Gly

(2) INFORMATION FOR SEQ ID NO: 4:

(i) SEQUENCE CHARACTERISTICS:

(A) LENGTH: 4 amino acids

(B) TYPE: amino acid (D) TOPOLOGY: linear

(ii) MOLECULE TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 4: Gly Phe Leu Gly (2) INFORMATION FOR SEQ ID NO: 5:

(i) SEQUENCE CHARACTERISTICS:

(A) LENGTH: 13 amino acids

(B) TYPE: amino acid (D) TOPOLOGY: linear

(ii) MOLECULE TYPE: peptide

(xi) SEQUENCE DESCRIPTION: SEQ ID NO : 5 : Gly Phe Leu Gly Glu Asp Pro Gly Phe Phe Asn Val Glu 1 5 10

(2) INFORMATION FOR SEQ ID NO: 6:

(i) SEQUENCE CHARACTERISTICS:

(A) LENGTH: 20 base pairs (B) TYPE: nucleic acid

(C) STRANDEDNESS : single

(D) TOPOLOGY: linear

(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 6:

GTAACAATGC CATGTTCAAT 20

(2) INFORMATION FOR SEQ ID NO: 7:

(i) SEQUENCE CHARACTERISTICS:

(A) LENGTH: 21 base pairs

(B) TYPE: nucleic acid

(C) STRANDEDNESS: single (D) TOPOLOGY: linear

(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 7

CTCCATCGTG GGCCGCTCTA G 21

(2) INFORMATION FOR SEQ ID NO: 8: (i) SEQUENCE CHARACTERISTICS:

(A) LENGTH: 22 base pairs

(B) TYPE: nucleic acid

(C) STRANDEDNESS: single (D) TOPOLOGY: linear

(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 8:

CTTAGTTGCG TTACACCCTT TC 22

(2) INFORMATION FOR SEQ ID NO: 9:

(i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 23 base pairs

(B) TYPE: nucleic acid

(C) STRANDEDNESS: single

(D) TOPOLOGY: linear

(xi) SEQUENCE DESCRIPTION: SEQ ID NO : 9 : GGGCCATTCT CCTTAGAGAG AAG 23

Claims

ClaimsWe claim:

1. A composition for intracellular delivery of a chemical agent capable of eliciting a selected effect when delivered intracellularly into a T lymphocyte, said composition having the formula:

[L-S]_a-C-[S-A]_b wherein L is a ligand capable of binding to a receptor on said T lymphocyte and stimulating receptor-mediated endocytosis of said composition; A is said chemical agent; S is a spacer; C is a water soluble polymer having functional groups compatible with forming covalent bonds with said ligand, chemical agent, and spacer; and a and b are integers of at least 1.

2. The composition of claim 1 wherein C is selected from the group consisting of polyethylene glycol and activated derivatives thereof.

3. The composition of claim 2 wherein said ligand is a peptide with an amino acid sequence identified as SEQ ID NO:l.

4. The composition of claim 3 wherein said chemical agent is selected from the group consisting of cytotoxins, transforming nucleic acids, gene regulators, labels, antigens, and drugs.

5. The composition of claim 4 wherein said spacer is biodegradable.

6. The composition of claim 5 wherein said spacer comprises a peptide.

7. The composition of claim 6 wherein said spacer comprises Gly-Phe-Leu-Gly (SEQ ID N0:4).

8. The composition of claim 7 wherein said chemical agent is adriamycin.

9. The composition of claim 4 further comprising a carrier selected from the group consisting of water soluble polymers, liposomes, and particulates .

10. The composition of claim 9 wherein said carrier is a water soluble polymer selected from the group consisting of dextran, inulin, poly (L-lysine) with modified epsilon amino groups, poly (L-glutamic acid) , and N-substituted methacrylamide-containing polymers .

11. A method of delivering a chemical agent in vitro into a T lyphocyte in a heterogeneous population of cells, comprising the steps of:

(a) providing a composition for intracellular delivery of a chemical agent capable of eliciting a selected effect when delivered intracellularly into a T lymphocyte, said composition having the formula:

[L-S]_a-C-[S-A]_b wherein L is a ligand capable of binding to a receptor on said T lymphocyte and stimulating receptor-mediated endocytosis of said composition; A is said chemical agent; S is a spacer; C is a water soluble polymer having functional groups compatible with forming covalent bonds with said ligand, chemical agent, and spacer; and a and b are integers of at least 1; and (b) contacting said population of cells with an effective amount of said composition under conditions wherein said ligand binds to said receptor on T lymphocytes and elicits endocytosis of said composition.

12. The method of claim 11 wherein C is selected from the group consisting of polyethyleneglycol and activated derivatives thereof.

13. The method of claim 12 wherein said ligand is a peptide with an amino acid sequence identified as SEQ ID N0:1.

14. The method of claim 13 wherein said chemical agent is selected from the group consisting of cytotoxins, transforming nucleic acids, gene regulators, labels, antigens, and drugs.

15. The method of claim 14 wherein said spacer is biodegradable.

16. The method of claim 15 wherein said spacer comprises a peptide.

17. The method of claim 16 wherein said spacer comprises Gly-Phe-Leu-Gly (SEQ ID NO: 4).

18. The method of claim 17 wherein said chemical agent is adriamycin.

19. The method of claim 14 further comprising a carrier selected from the group consisting of water soluble polymers, liposomes, and particulates .

20. The method of claim 19 wherein said carrier is a water soluble polymer selected from the group consisting of dextran, inulin, poly (L-lysine) with modified epsilon amino groups, poly (L-glutamic acid), and N-substituted methacrylamide-containing polymers.

21. A method of delivering a chemical agent intracellularly into a T lymphocyte in a warm-blooded animal, comprising the steps of:

[L-S]_a-C-[S-A]_b wherein L is a ligand capable of binding to a receptor on said T lymphocyte and stimulating receptor-mediated endocytosis of said composition; A is said chemical agent; S is a spacer; C is a water soluble polymer having functional groups compatible with forming covalent bonds with said ligand, chemical agent, and spacer; and a and b are integers of at least 1; and

(b) systemically administering to said warm- blooded animal an effective amount of said composition under conditions wherein said ligand contacts and binds to said receptor on T lymphocyte and elicits endocytosis of said composition.

22. The method of claim 21 wherein C is selected from the group consisting of polyethyleneglycol and activated derivatives thereof.

23. The method of claim 22 wherein said ligand is a peptide with an amino acid sequence identified as SEQ ID N0:1.

24. The method of claim 23 wherein said chemical agent is selected from the group consisting of cytotoxins, transforming nucleic acids, gene regulators, labels, antigens, and drugs.

25. The method of claim 24 wherein said spacer is biodegradable.

26. The method of claim 25 wherein said spacer comprises a peptide.

27. The method of claim 26 wherein said spacer comprises Gly-Phe-Leu-Gly (SEQ ID NO: 4).

28. The method of claim 27 wherein said chemical agent is adriamycin.

29. The method of claim 24 wherein further comprising a carrier selected from the group consisting of water soluble polymers, liposomes, and particulates.

30. The method of claim 29 wherein said carrier is a water soluble polymer selected from the group consisting of dextran, inulin, poly (L-lysine) with modified epsilon amino groups, poly (L-glutamic acid), and N-substituted methacrylamide-containing polymers.