IE871727L - Novel family of primate il3-like hematopoietic growth¹factors. - Google Patents

Description

v . T / 7060S 1 A NOVEL FAMILY OF PRIMEHT HEMATOPOIETIC GROWTH FACTORS The present invention relates to a novel family of primate IL-3-like hematopoietic growth factors, and a 5 process for producing them by recombinant genetic engineering techniques.

Hematopoietins, i.e., hematopoietic growth factors, 10 are proteins that promote the survival, growth and differentiation of hematopoietic cells. Colony stimulating factors (CSFs) are a subset of these hematopoietic growth factors that are characterized by the ability to support the growth, in vitro. of colonies of hematopoietic cells 15 arising from progenitor cells of bone marrow, fetal liver, and other hematopoietic organs.

The biochemical and biological identification and characterization of certain hematopoietins was hampered by the small quantities of the naturally occurring factors 20 available from natural sources, e.g., blood and urine. Some of these hematopoietins have recently been molecularly cloned, heterologously expressed and purified to homogeneity. [D. Metcalf, "The Molecular Biology and Functions of the Granulocyte-Macrophage Colony Stimulating Factors," Blood. 25 (57 (2) :257-267 (1986).] Among these hematopoietins ate human and murine GM-CSF, human G-CSF, human CSF-1 and murine IL-3. Human GM-CSF [R. Donahue et al,, Nature. 321: 872-875 (1986)], murine IL-3, [J. Kindler et al, Proc. Natl. Acad. Sci. U.S.A. . £3.: 1001-1005 (1986); Metcalf et al., 30 Blood. 68:46-57 (1986)] and human G-CSF [K. Welte et al, Exp. Med.. 165;941-948 (1987)] have demonstrated effects on hematopoiesis in vivo. Despite extensive research with the murine protein IL-3, no human counterpart had heretofore 70605 2 been found. [D.R. Cohen et al, Nucl. Acids Res., 14:3641 (1986)].

The present invention relates to a family of primate IL-3-like growth factors substantially fras from other private proteins and characterized by peptide sequences the same as or substantially homologous to the amino acid sequences illustrates in Tables I and II below. These primate proteins, including especially the human proteins, are also referred to hereinafter simply as IL-3. These proteins are encoded by the DNA sequences depicted in the Tables and by sequences capable of hybridizing thereto, or capable of hybridizing thereto but for the degeneracy of the genetic code, which encode polypeptides with IL-3-like biological properties, and by other variously modified sequences demonstrating such properties. These polypeptides are also characterized by IL-3-like biological properties.

As one example, the invention provides a DNA sequence that encodes a polypeptide comprising one or more of the mature peptide sequences as shown in Table I or Table II wherein amino acid 27 is Serine and which possesses at least one of the biological properties of primate IL-3, said biological properties being selected from the group consisting of : (a) the ability to support the growth and differentiation of primate progenitor cells committed to erythroid, lymphoid and myeloid lineages; (b) the ability to stimulate granulocytic colonies and erythroid bursts in a standard human bone marrow assay; (c) the ability to sustain the growth of primate pluripotent precursor cells; and (d) the ability to stimulate primate chronic myelogenous leukemia (CML) cell proliferation in the CML assay or ' - ; 3 a DNA sequence capable of hybridizing under relaxed or stringent conditions, or which would be capable of hybridizing under said conditions but for the degeneracy of the genetic code, to a DNA sequence 5 selected from the group consisting of : (a) the DNA sequence of Table I; (b) the DNA sequence of Table II, wherein the codon for amino acid 27 is TCC; (c) the Xhol insert in.pXM (ATCC 67154); and (d) the BamHI or Bglll genomic insert in bacteriophage lambda M13 cloning vector mp9 (ATCC 4024 6); said DNA encoding a polypeptide having at least one biological property of primate IL-3, selected from the group consisting of : (i) the ability to support the growth and differentiation of primate progenitor cells committed to erythroid, lymphoid and myeloid lineages; (ii) the ability to stimulate granulocytic 20 colonies and erythroid bursts in a standard human bone marrow assay; (iii) the ability to sustain the growth of primate pluripotent precursor cells; and (iv) the ability to stimulate primate chronic 25 myelogenous leukemia (CML) cell proliferation in the CML assay.

These DNA sequences can be human or gibbon DNA sequences and, furthermore, comprise cDNAs.

TJtie invention also provides polypeptides or proteins encoded 30 by the DNA sequences mentioned above. In a preferred embodiment, said polypeptides or proteins have the amino acid sequence given in Table I or in Table II, wherein the amino acid sequence of Table II contains the amino acid Serine at position 27, said protein being optionally 35 devoid of the Methionyl residue at the N-terminus.

In a further preferred embodiment, said polypeptides or proteins have a molecular weight of about 14,000 to about 35,000 as determined by reducing SDS polyacrylamide gel electrophoresis. 4 Another aspect of the invention provides pharmaceutical compositions containing a therapeutically effective amount of one or more polypeptides according to the invention. These compositions may be employed in methods for treating a number 5 of disease states characterized by a deficiency in the level of hematopoietic cells. These methods according to the invention entail administering to a patient an effective amount of at least one polypeptide as described herein.

Such therapeutic methods may be directed to treat various 10 pathological states resulting from disease, exposure to radiation and/or drugs, including e.g., leukopenia, thrombocytopenia, anemia, B cell deficiency, T cell deficiency, bacterial infection, and viral infection, including immune ceil or hematopoietic cell deficiency following a bone marrow transplantation. These 15 methods of the present invention may also include administering simultaneously or sequentially with the IL-3-like polypeptides, an effective amount of at least one other henatopoietin, interleukin, or growth factor. Exemplary hematopoietins for such use include GM-CSF, G-CSF, CSr-1 or erythropoietin. 20 Exemplary interleukins are IL-1, IL-2, IL-4 or IL-6. The methods may also employ growth factors like a B cell growth factor, a B cell differen-tiation factor/ or an eosinophil differentiation factor.

Still a further aspect of the invention are vectors 25 containing, and cells transformed with, a DNA sequence as described above, preferably in operative association with an expression control sequence. such vectors and transformed cells nay be a employed in a novel process for producing a primate IL-3-like polypeptide in which a cell line transformed with a DNA 30 sequence encoding expression of an IL-3-like polypeptide in operative association with an expression control sequence therefor is cultured. This claimed process may employ a number of known cells as host cells for expression of the polypeptide. Presently preferred cell lines are mammalian cell lines 35 bacterial cells and yeast cells.

Other aspects and advantages of the present invention will be apparent upon consideration of the following detailed description of preferred embodiments thereof.

The family of primate IL-3-like growth, iactors provided by the present invention are polypeptides or proteins encoded by the DNA sequences mentioned above. In a preferred embodiment, said polypeptides or proteins have the amino acid 5 sequence given in Table I or in Table II, wherein the amino acid sequence of Table II contains the amino acid Serine at position 27, said protein being optionally devoid of the Methionyl residue at the N-terminus. 10 In a further preferred embodiment, said polypeptides or proteins have a molecular weight of about 14,000 to about ,000 as determined by reducing SDS polyacrylamide gel electrophoresis.

Preferably more than one IL-3-like biological property 15 is demonstrated by any one member of the family of growth factors of the present invention.

The term "IL-3-like biological property" is defined herein to include one or more of the following biological characteristics and in vivo and in vitro activities. One such property is the 20 suooort of the growth and differentiation of progenitor calls committed to erythroid, lymphoid, and myeloid lineages. For example, in a standard human bone marrow assay, an IL-3-like biological property is the stimulation of granulocytic type colonies and erythroid bursts. Another such property is the 25 interaction with early multipotential stem cells.

Another IL-3-like biological property is the sustaining of the growth of pluripotent precursor cells. Another property is the ability to stimulate chronic myelogenous Leukemia (CML) cell proliferation. An IL-3-like biological property, also is the 30 stimulation of proliferation of mast cells. IL-3-like growth factors may also support the growth of various factor-dependent cell lines and/or induce the expression of 20-alpha-steroic dehydrogenase (20-alpha-SPH) and Thv-1 antigen. Further IL-3-like biological properties are the stimulation of colony formation 35 on KG—1 cells and/or the stimulation of increased histamine synthesis in spleen and bone marrow cultures. Vet another IL-3 biological property is an apparent molecular weight of between about 14 to about 35 kd by reducing sodium dodecyl sulfate polyacrylamide gel electrophoresis. Other biological properties of IL-3-like proteins have been disclosed in the art with reference to marine IL-3.

The specific peptide sequences illustrated in Tables I and 5 II are two exemplary members of the growth factor family of the present invention. The 865bp DNA- sequence of Table I was isolated from a cDNA expression library of the gibbon ape leukemia virus-infected gibbon T-cell line UCD-K4-MLA [T.G. Kuwakami et al, Nature. 235:170 (1972)]. This sequence contains a single long open reading frame of 456 nucleotides which encodes an approximately 152 amino acid protein, called CSF-80, and includes a conventional leader secretory sequence indicated by the highly hydrophobic sequence (leu leu leu leu gin leu leu). The mature protein begins at amino acid number 15 20, alanine, in Table I. The coding region contains three cysteines, two in the mature protein, thereby suggesting one disulfide bond. There are two potential asparagine-1 inked glycosylation sites illustrated by the characteristic sequences, Asn-X-Ser or Asn-X-Thr. Both the size and glycosylation pattern 20 revealed by the coding sequence are typical of lymphokine-like proteins. The remaining non-coding portions of the 865bp region may have a regulatory role in transcription in the natural host. The 3* end of the sequence also contains an AT-rich segment including several repeats of the sequence 25ATTTA, which is believed to be related to the RNA message stability [See, G. Shaw and R. Kamen, Cell. 46 (5): 659-677 (1986)]. 7 Table X 20 30 49 CTOSAGCEAC GDCAAOSAAA AAIAAAATOC AAAC ATG AGC TGC CDS CCC (SIC CTG CDC MET Ser cys Leu Pro Val Leu Leu 64 79 94 109 CDS CDC CAA CTC CDS GTC AGC OGC GGA CDC CAA GCT COC ATS AOC CAG ACA AOG leu Leu Gin Leu Leu Val Ser Pro Gly Leu Gin Ala Pro MET Thr Gin Thr Thr 124 139 154 TOC TIG AAG ACA AGC TSG GST AAC 1GT TCI AAC ATS ATC GAT GAA AIT ATA ACA Ser Leu Iys Thr Ser Ttp Val Asn Cys Ser Asn MET lie Asp Glu lie lie Thr 169 184 199 214 CAC TEA AAG CAG CCA OCT TIG CCC TIG CTC GAC TDC AAC AAC CTC AATGGG GAA His Leu Iys Gin Pro Pro Leu Pro Leu Leu Asp Hie Asn Asn Leu Asn Gly Glu 229 244 259 274 GAC CAA GAC ATT CDS ATC GAA AAT AAC CTT CGA AGG OCA AAC CTG GAG GCA TIC Asp Gin Asp lie Leu MET Glu Asn Asn Leu Arg Arg Pro Asn Leu Glu Ala Fhe 289 304 319 AAC AAG GCT GTC AAG AG! TTA CAG AAT GCA TCA GCA ATC GAG AGC ATT CIT AAG Asn Iys Ala Val Iys Ser Leu Gin Asn Ala Ser Ala lie Glu Ser lie Leu Lys 334 349 364 379 AAT CTC CCC CCA TGC CDS COC ATS GOC ACA GOC GCA COC AOG OGA CAT OCA ATC Asn Leu Pro Pro Cys Leu Pro MET Ala Thr Ala Ala Pro Thr Arg His Pro lie 394 409 424 OGT ATC AAG GAC GGT GAC TSG AAT GAA TTC OGG AGG AAA CTG AAG TTC TAT CDS Arg lie lys Asp Gly Asp Trp Asn Glu Fhe Axg Arg lys Leu lys Hie tyr Leu 439 454 469 484 AAA AOC CTT GAG AAT GAG CAA GCT CAA CAG ATS ACT TIG AGC CTT GAG ATC TCT Iys Thr leu. Glu Asn Glu Gin Ala Gin Gin MET Thr Leu Ser-Leu Glu lie Ser 500 510 520 530 540 550 560 TGAGTQCAAC GTOCflGCTCT CBCKTOGGC GGTCTCAOOS CAGAGOCTCA GSACATCAAA AACAGCAGAA 570 580 590 600 610 620 630 cnosAAAc ciuiuayros tcdcdcacac agkeaggac cagaagcatt TCAOCITTTC ctsosgcatc 640 650 660 670 680 690 700 AGKEGAATXG TEAATIATCT AA3TTCTGAA ATSESCAGCT COCKETTSSC CTTGiIGIGGT ■JLUimTCICA 8 Table I (cont'd) 710 720 730 740 750 760 770 TITTXKPOCC AXTSUSMZEA TrEKTGQMXG TdGTATlTft. 'ITiM'JLTAlT TATTTATIGC CITCIGGAGC 780 790 800 810 820 830 840 GTOAAGDSIA TITtflTLCAG CAGAGGAGCC A3STCA2GCT GCTTCIGCAA AAAACTCAAG AGTCGGGTGG 850 860 GGAGC&TCTT CAITTGEACC TGGftG The 674bp DNA sequence of Table II was obtained from a human genomic library [J. J. Toole et al, Nature. 312:342-346 (1984)] by employing the sequence of Table 1 as a probe. The DNA sequence of Table II was initially constructed by splicing together the exons of the human genomic sequence, which were identified by comparison with the DNA sequence of the gibbon IL-3-like polypeptide of Table I. This hunan sequence confirmed by mRNA analysis of the human cDNA clone also codes for a polypeptide of approximately 152 amino acids, which is a member of this family of primate proteins. This human polypeptide includes a conventional leader secretory sequence indicated by the highly hydrophobic sequence (leu leu leu gin leu leu). The mature polypeptide begins at amino acid number 20, alanine, in Table II. The coding region contains two cysteines in the mature protein, suggesting one disulfide bond. There are two potential asparagine-1inked glycosylation sites illustrated by the characteristic sequence, Asn-X-Ser. The remaining non-coding portions of the 674bp sequence may have a regulatory role in transcription in the natural host.

The nucleotide sequences of the exons of the human genomic gene [Table II] were more than 96% homologous with the DNA sequence of the gibbon gene [Table I]. Changes in the nucleotide sequences in 11 codons result in amino acid differences in the gibbon and human proteins. The nucleotides appearing above the sequence of Table II indicate the sites where the gibbon sequence differs from the related human sequence. Similarly, the amino acids appearing below the human amino acid sequence indicate where the gibbon sequence differs. • 4 Table XI A 9 T 24 39 A54 GATOCAAAC MG AGC GGC CTG COC GTC CIG CTC GIG CTC CAA CTC C3G GTC OGC MET Ser Arg Leu Pro Val Leu Leu leu Leu Gin Leu Leu Val Axg Cys Ser (27) 69 84 [C] 99 GOC GGA CTC CAA GCT COC A3G AOC CAS ACA AOG TOC ITS AAG ACA AGC TSG CTT Pro Gly leu Gin Ala Pro MET Oar Gin 2br Thr Ser Leu Lys Thr Ser Trp Val 114 T 129 144 159 AAC TGC TCT AAC ATS ATC GAT GAA ATT ATA ACA CAC TEA AAG CAG OCA OCT TIG Asn cys Ser Asn MET lie Asp Glu lie lie Thr His leu lys Gin Pro Pro leu 50 C 174 189 204 OCT TIG CTG GAC TTC AAC AAC CTC AAT GGG GAA GAC CAA GAC AIT CDS ATS GAA Pro Leu Leu Asp Rie Asn Asn Leu Asn Gly Glu Asp Gin Asp lie Leu MET Glu 219 234 249 A 264 AAT AAC CIT CGA AGG OCA AAC CIG GAG GCA TTC AAC AGS GCT GTC AAG ACT TEA Asn Asn Leu Arg Axg Pro Asn Leu Glu Ala Phe Asn Axg Ala Val lys Ser Leu lys T 279 C 294 G 309 OC C 324 CAG AAC GCA TCA GCA AST GAG AGC AST CZT AAA AAT CTC CIG OCA TCT CIG CCC Gin Asn Ala Ser Ala He Glu Ser He Leu lys Asn Leu Leu Pro cys Leu Pro 100 Pro A A 339 354 G 369 CTG GOC AOS GOC GCA COC AOS OS& CAT CCA ATC CAT ATC AAG GAC GCT GAC TOG Leu Ala Thr Ala Ala Pro Thr Axg His Ko^He His He lys Asp Gly Asp Trp MET Axg 429 384 399 A 414 A A AAT GAA TTC OSS AGS AAA CIG AOS TTC TAT CZG AAA AOC CTT GAG AAT GGS CAG Asn Glu Hie Arg Arg lys Leu Thr She tyr Leu lys Thr Leu Glu Asn Ala Gin 130 lys Glu 444 459 485 T T A C G 475 TC 495 GCT CAA CAG ACS ACT TZG AGC CTC GGS ATC TIT T-AGPOCAAOS TCCAGCTOSr TCTCTGQGCC Ala Gin Gin Bir Bar Leu Ser Leu Ala He She MET 147 Glu Ser 11 Sable H (cxnt'd) 505 515 555 C G A A 525 535 545 G 565 3TCXCA0CAC AGOGGCBOQG GACKFCAAA& ACAGCAGAAC 27CXGAAAOC TCTGGCTCAT CTCTCACACA G 575 585 595 605 615 625 635 TTCCAGGAGC AGAAGCAITT CaCCTTTlCC TCCGGCATCA GA3GAAXZUT TftAITATCIA ATTTCIGAAA 645 655 T 665 TGTCCaGCK: CCftlTIGGCC TTGTGCQGTT GTCTTCTCA 12 A computer search by National Biomedical Services of Washington, D. C. revealed that the gibbon and human IL-3-like sequences have approximately 29% homology at the amino acid level and 45% homology at the nucleotide level to the murine IL-3 DNA. sequence, as published by M. C. Fung et al., Nature. 3075233-237 (1984). Exon structures of the human IL-3-like gene compared similarly with the coding regions of the murine IL-3.

The novel 865bp cDNA sequence illustrated in Table I included in a plasmid in £. coli HB101, has been deposited in the American Type Culture Collection, 12301 Parklawn Dr., Rockville, MD on July 11, 1986 and given accession number ATCC 67154. The novel genomic sequence, for which the cDNA sequence is illustrated in Table II below, included in bacteriophage lambda, has been similarly deposited on August 7, 1986 and given accession number ATCC 40246. The human IL-3 DNA included in plasmid pSHIL-3-1 in £. coli HB101 has been deposited in the ATCC on February 24, 1987 and given accession number ATCC 67326.

The exemplary human and gibbon IL-3-like polypeptides have been further characterized by SDS polyacrylamide gel analysis of the 35s-labeled proteins from transfected COS cells, as described below in the examples. Both polypeptides are heterogenous in size with molecular species having a range of apparent molecular weight of between about 14kd-35kd, and more .specifically, 18kd-30kd. This range, of molecular weights for these exemplary IL-3-like factors is believed to result from variations in glycosylation of the purified COS cell produced molecules. The purified proteins, at 10 to 100^picomolar concentrations, cause the formation of small granulocytic-type colonies in In vitro human bone marrow assays. Additionally, in the presence of erythropoietin in these human bone marrow assays both polypeptides support the growth of erythroid and myeloid progenitor cells at comparable levels of activity. Thus these IL-3-like factors are multi-CSFs. These IL-3-like factors also cause the proliferation of leukemic blast calls from patients with CML. These polypeptides nay also be capable of stimulating accessory and mature cells, e.g. monocytes, to produce other hematopoietic-like factors, which in turn stimulate the formation of colonies of other hematopoietic cells, as well as other hematopoietic-type activities.

Also included in the present invention are synthetic polypeptides which wholly or partially duplicate continuous sequences of the amino acid residues of Tables I and II. Methods for constructing the polypeptides of the present invention by synthetic means are known to those of skill in the arz. The synthetically-constructed sequences, by virtue of sharing primary, secondary, or tertiary structural and conformational characteristics with IL-3-like polypeptides of Tables I and II may possess IL-3-like biological properties in common therewith. Thus, they may be employed as biologically active or immunological substitutes for natural, purified primate IL-3-like polypeptides in therapeutic and immunological processes.

The family of IL-3-like growth factors provided herein also includes factors encoded by the sequences similar to those of Tables I and II, but into which modifications are naturally provided or deliberately engineered. For example, one such modified human protein has the mature peptide sequence depicted in Table II except that Ser-27 is replaced by Proline. That protein is encoded by a human cDNA sequence as illustrated in Table II with the modificiation that the proline codon CCC is present at amino acid position #27 instead of the serine codon TCC which appears in the Table at that position. This exemplary modified IL-3-like DNA sequence, which produces an active human IL-3-like factor, included £n E. coli HB101 as pHucIL3-2, was deposited in the ATCC on February 13, 1987 under accession number ATCC 67319.

EP-A 0 275 589, which is a document pursuant to Art. 54(3) EPC, also discloses a sequence in which the amino acid position corresponding to amino acid position 27 of Table II is Pro and the codon corresponding to codon 27 of Table II is TCC. 14 Other modifications in the peptide or sequences can be made by one skilled in the art using known techniques. Specific modifications of interest in these IL-3-like related sequences nay include the replacement of one or both of the two cysteine 5 residues in each coding sequence with other amino acids. Preferably both cysteines are replaced with another'amino acid, e.g. serine, to eliminate the disulfide bridge. Mutagenic techniques for such replacement are well known to one skilled in the art. [See, e.g.. United States patent 4,518,584.] 10 Other specific mutations of the sequences of the IL-3-like factors described herein involve modifications of one or both of the glycosylation sites. The absence of glycosylation or only partial glycosylation results from amino acid substitution or deletion at one or both of the asparagine-linked glycosylation 15 recognition sites present in the sequences of the IL-3-like factors shown in Tables I and II. The asparagine-linked glycosylation recognition sites comprise tripeptide sequences which are specifically recognized by appropriate cellular glycosylation enzymes. These tripeptide sequences are either 20 asparagine-X-threonine or asparagine-X-serine, where X is usually any amino acid. A variety of amino acid substitutions or deletions at one or both of the first or third amino acid positions of a glycosylation recognition site (and/or amino acid deletion at the second position) results in non-glycosylation 25 at the modified tripeptide sequence.

For example, of the sequence of Table I can be replaced with glutamine in one such modified IL-3-like factor. The resulting factor (Glnj^ should contain only one aspardgine-linked carbohydrate moiety (at Asngg), rather than two such 30 moieties. Those skilled in the art will appreciate that analogous glycoproteins having the same Asn89 monoglycosy 1 at ion may be prepared by substituting another amino acid at position 34, and/or by substituting another amino acid at the other positions within the glycosylation recognitions site, e.g., inserting 35 valine at Ser3£. Similarly, the Asn codon corresponding to position 89 and/or the serine codon corresponding to position 91 nay be altered by a mutagenic technique to codons for other amino acids. Expression of such altered nucleotide sequences produces variants which are riot glycosylated at that site. Alternatively, both sites aay be altered as above. Such modifications to the glycosylation sites may also be siace to create modifications of the sequence of Table II. [See, e.c.

A. Hiyajima et al. , 5M3Q J.. 5.(6) : 1993-1197 (1986) and Example" XV below. ] Other analogs and derivatives of the sequences of Tables I and II which would be expected to retain IL-3-like activity in whole or in part aay also be easily made by one of skill in the art given the disclosures herein. Such obvious 10 modifications are believed to be encompassed by this invention.

The present invention also encompasses the novel DNA sequences mentioned above coding on expression for primate IL-3-like polypeptides or growth factors. These DNA sequences include those depicted in Table I and Table II in a 5' to 3' 15 direction and those sequences which hybridize under stringent hybridization conditions (see, T. Maniatis et al, Molecular Cloning (A Laboratory Manual) . Cold Spring Harbor Laboratory (1982), pages 387 to 389] to the DNA sequences of Tables 1 and II. An example of one such stringent hybridization condition 20 is hybridization at 4XSSC at 65°C, followed by a washing in 0.1XSSC at 65°C for an hour. Alternatively an exemplary stringent hybridization condition is in 50% formamide, 4XSSC at 42°c.

DNA sequences which hybridize to the sequences of Tables 1 or II under relaxed hybridization conditions and which code on 25 expression for growth factors having primate IL-3-like biological properties also encode members of this family of novel growth factors. Examples of such non-stringent hybridization conditions are 4XSSC at 50°C or hybridization with 30-40% fonaamide at 42°C. For example, a DNA sequence which shares regions of 30 significant homology, e.g., sites of glycosylation or disulfide linkages, with the sequences of Tables I and/or II and encodes a primate protein having one or more IL-3-like biological properties clearly encodes .a member of this novel family ox growth factors, even if such a DNA sequence would not stringently 16 hybridize to the sequence of Table I or II.

Similarly, DNA sequences which code for primate IL-3-like polypeptides coded for by the sequence of Table I or II, but * which differ in codon sequence due to the degeneracies of the 5 genetic code or allelic variations (naturally-occurring base changes in the species population which may or may not result in an amino acid change) also encode the novel growth factors of this family described herein. Variations in the DNA sequences of Tables X and XI which are caused by point mutations or by 10 induced modifications to enhance the activity, half-life or production of the polypeptides encoded thereby are also encompassed in the invention.

Another aspect of the present invention provides a novel method for producing the novel family of primate IL-3-like 15 growth factors. The method of the present invention involves culturing a suitable cell or cell line, which has been transformed with a DNA sequence coding on expression for a novel primate IL-3-like polypeptide under the control of known regulatory sequences. Suitable cells or cell lines may be 20 mammalian cells, such as Chinese hamster ovary cells (CHO) or 3T3 cells. The selection of suitable mammalian host cells and methods for transformation, culture, amplification, screening and product production and purification are known in the art. See, e.g., Gething and Sambroojc, Nature. 293:620-625 (1981), or 25 alternatively, Kaufman et al, Mol. Cell. Biol.. *>(7): 1750-1759 (1985) or Howley et al, U.S. Patent 4,419,446. Another suitable mammalian cell line, which is described in the accompanying examples, is the monkey COS-1 cell line. A similarly useful mammalian cell line is the CV-l cell line.

Similarly useful as host cells suitable for the present invention are bacterial cells. For example, the various strains of £. coli (e.g., HB101, MC1061 and strains used in the following examples) are well-known as host cells in the field of biotechnology. Various strains of fi. subtil is. Psaudomonas. 35 other bacilli and the like may also be employed in this method. 17 Many strains of yeast cells known to those skilled in the art are also available as host cells for expression of the polypeptides of the present invention. Additionally, where desired, insect cells nay be utilized as host cells in the 5 method of the present invention. See, e.g. Miller et al,-Genetic Engineering. 1:277-298 (Plenum Press 1986) and references cited therein.

Another aspect of the present invention provides vectors for use in the method of expression of these novel primate 10 polypeptides. These vectors contain the novel DNA sequences described above which code for the novel primate polypeptides of the invention. Alternatively, vectors incorporating modified sequences as described above are also embodiments of the present invention and useful in the production of these IL-3-like 15 polypeptides. The vector employed in the method also contains selected regulatory sequences in operative association with the DNA coding sequences of the invention and capable of directing the replication and expression thereof in selected host cells.

The members of the novel family of primate IL-3-like 20 growth factors herein disclosed may be used in the treatment of a number of pathological or disease states, particularly those characterized by a decreased level of either myeloid, erythroid, lymphoid, or megakaryocyte cells of the hematopoietic system or combinations thereof. In addition, they may be used to activate 25 mature myeloid and/or lymphoid cells. Among conditions susceptible to treatment with the polypeptides of the present invention is leukopenia, a reduction in the number of circulating leukocytes (white cells) in the peripheral blood. Leukopenia may be induced by esqposure to certain viruses or to radiation. 30 it is often a side effect of various forms of cancer therapy, e.g., exposure to chemotherapeutic drugs. Therapeutic treatment of leukopenia with these IL-3-like polypeptide compositions may avoid undesirable side effects caused by treatment with presently available drugs.

Various immunodeficiencies e.g., in T and/or B lympho 18 cytes, or immune disorders, e.g., rheumatoid arthritis, may also be beneficially effected by treatment with the polypeptides of the present invention. These factors, alone or in combination with other treatment regimens, may be useful in treating or correcting immunodeficiencies which are the result of viral infections e.g. HTLVI, HTLVII, HIV, severe exposure to radiation, cancer therapy or the result of other medical treatment. The polypeptides of the present invention may also be employed, alone or in combination with other hematopoietins, in the treatment of other blood cell deficiencies, including thrombocytopenia (platelet deficiency), or anemia (red cell deficiency). Other uses for these novel polypeptides are in the treatment of patients recovering from bone marrow transplants, and in the development of monoclonal and polyclonal antibodies generated by standard methods for diagnostic or therapeutic use.

Therefore, as yet another aspect of the invention are therapeutic compositions comprising one or more of the polypeptides or proteins of the invention in admixture with a pharmaceutically acceptable carrier. Said polypeptides or 25 proteins can be furthermore used for the preparation of a therapeutical composition for treating the conditions referred to above. Such compositions comprise a therapeutically effective amount of one or more of the members of the family of primate IL-3-like polypeptides of the present invention in 30 admixture with a pharmaceutically acceptable carrier. This composition can be systematically administered parenterally. Alternatively, the composition may be administered intravenously. If desirable, the composition may be administered subcutaneously. When systematically administered, the therapeutic composition 35 for use in this invention is in the form of a pyrogen-free, parenterally acceptable aqueous solution. The preparation of such a parenterally acceptable protein solution, having due regard to pH, isotonicity, stability and the like, is within the skill of the art. 40 The dosage regimen involved in a method for treating the above-described conditions will be determined by the attending physician considering various factors which modify the action of drugs, e.g. the condition, body weight, sex and diet of the patient, the severity of any infection, time of administration 19 and other clinical factors. Generally, the daily regimen should be in the range of 200~1000 micrograms of polypeptide or 50 to 5000 units (ie, a unit being the concentration of polypeptide which leads to half maximal stimulation in a standard 5 human bone marrow assay) of polypeptide per kilogram of body weight.

The therapeutic compositions of the present invention may also contain other human factors. A non-exclusive list of other appropriate 10 hematopoietins, CSFs and interleukins for simultaneous or serial co-administration with the polypeptides of the present invention includes GM-CSF, CSF-1, G-CSF, Meg-CSF, erythropoietin (EPO), IL-1, IL-4, IL-2, B-cell growth factor, B-cell differentiation factor and eosinophil differentiation factor. Of particular 15 interest for amplifying hematopoietic progenitor cells and their descendants in vivo is a combination of IL-3 with IL-6 (also known in the art as B cell stimulatory factor 2), which demonstrate the ability in human blast cell assays to cause the proliferation of early stem cell colonies. Additionally, the 2o IL-3-like polypeptides may be administered with, or chemically attached to, monoclonal or polyclonal antibodies in a therapeutic use. Alternatively, these growth factors may be attached to certain toxins, e.g., ricin, in a therapeutic regimen. The dosage recited above would be adjusted to. compensate for such 25 additional components in the therapeutic composition. Progress of the treated patient can be monitored by periodic assessment of the hematological profile, e.g. white cell count and the like.

The following examples illustratively describe members of 30 the novel family of primate IL-3-like polypeptides and the methods of the present invention.

EXAMPT.F T Isolation of Gibbon IL-3-like Gene A gibbon T-cell line infected with gibbon-ape leukemia virus, UCD-144-MLA, and available from the National Institute of Health Laboratories was induced with phytohemagglutihin and phorbol myri state acetate (PHA/PMA). Total SNA was prepared from these cells by the procedures of J.M. Chirgwin et al., 5 Biochea. 18:5294 (1979). Poly A*4* mRNA was selected and fractionated on a 10% to 30% sucrose gradient. To identify the mRNA encoding this novel hematopoietic factor, sixteen aliquots of sucrose gradient-fractionated mRNA from the UCD-144-MLA cell line were micro-injected into Xenopus laevis oocytes and the 10 resulting conditioned medium tested for the ability to stimulate the proliferation of leukemic blast cells in the presence of antibody to human GM-CSF as illustrated in the CML assay of Example V. mRNA from the sucrose gradient fractions identified as containing the message encoding ZL-3-like growth factor 15 activity was converted to double stranded cDNA by the procedure of u. Gubler and B.J. Hoffman, Gene. £5:263 (1983).

A COS cell expression vector, pXM, containing the SV40 enhancer, major adenovirus late promoter, DHFR coding sequence, SV40 late message poly A addition site and VaZ gene was linearized 20 with the. endonuclease enzyme Xhol, treated with DNA polymerase I large fragment in the presence of dTTP and ligated to equimolar amounts of cDNA, at a final DNA concentration of 100 ug/ml. The ligation products resulting from the Xhol digestion of pXM and the insertion of the Xhol adapted cDNA sequence were 25 transformed into £&. coli strain HB101 and plated on L+ Amp plates to generate a library of approximately 30xl03 colonies. [Other functionally similar expression vectors known in the art can also be used in this procedure as alternatives to pXM. ] The cDNA library in pXM was replica plated onto 30 nitrocellulose filters. Colonies from each filter were scraped into L. broth, and plasmid DNA was isolated. Each DNA sample was prepared from a pool of 200-300 bacterial colonies. The DNA was purified by the method of J. A. Meyers et al., J. Bacteriol. 127:1529 (1976). Monkey COS cells (ATCC CRL 1650) were 35 transfected with approximately 5 ug plasmid DNA per 106 COS 21 cells by DEAE mediated DNA trans feet ion and treated with chloroquine according to the procedures described in G. G. Wong et al.. Science; 228:810-815 (1985) and R. J. Kaufman et al. Mol. Cell Biol.. 2:1304 (1982). 72 hours following transfection, medium is harvested and assayed in the human CML assay, as described in Example V below. One pool produced conditioned medium with colony stimulating activity and CML proliferation activity completely resistant to neutralizing antiserum to GMCSF, and was selected for further analysis. Plasmid DNA from individual colonies picked from the original active pool was prepared and transfected to produce conditioned medium. This conditioned medium was assayed for CSF and CML proliferation activity. A single clone responsible for such activity was isolated. The cDNA insert of this clone was subcloned into M13 and was sequenced by the Sanger dideoxy chain termination method. [See Table I] EXAMPLE II Isolation of a Human IL-3-like Gene Using the sequence of Table I as a probe., 1x106 clones from a human genomic library (Sau 3AI partial digest of human DNA cloned into the Bam HI site of the lambda vector Jl) [J. J. Toole et al, supra 1 were screened. Three plaques were identified which contained sequences which hybridized strongly with the cDNA probe. The DNAs from two of these phages were digested to completion with the endonuclease enzyme Sau 3AX and subcloned into the Bam HI site of the bacteriophage lambda M13 cloning vector mp9. Subclones containing exon sequences were identified by hybridization with the gibbon cDNA. One subclone, lambda CSF-16, containing the human genomic DNA sequence as an approximately lOkb Bgl II insert, was deposited with the ATCC as described above. The complete sequences of all of the exons of the human gene were determined using dideoxy chain termination DNA sequencing with a battery of oligonucleotide primers whose sequences were based upon the sequence of the gibbon gene 22 described in Example I. Because the nucleotide sequences of the exons of the human gene were more than 96% homologous with the sequence of the gibbon cDNA, the nucleotide sequence of the corresponding human cDNA was reconstructed. Changes in the 5 nucleotide sequences in 11 codons result in amino acid differences in the polypeptides from the two species. [See Table II].

The human genomic sequence can be excised from lambda CSF-16 and inserted into an expression vector, numerous types of which are known in the art for mammalian, insect, yeast, fungal, 10 and bacterial expression. For example, the human genomic sequence was excised from the deposited bacteriophage by digestion with the endonucleases Smal and Xhol which cleave the human gene region at nucleotides 629 and 3183 respectively. The resulting 2.5kb contains the entire human IL-3 gene coding 15 sequences and includes the "TATAA-related" sequence in the promoter region but lacks the "CAT-related" sequences and the polyadenylation signal at the 3* end of the gene. The Smal end of this fragment was converted to Xhol with a commercially available linker sequence. This fragment was sub-cloned by 20 standard molecular biology techniques [see, e.g., Y-C. Yang et al, ,£Z:3-10 (1986)] into a Xhol-digested plasmid expression vector pXM, yielding plasmid pY3. pY3 was then amplified in bacteria and transfected into monkey COS-1 cells, where the human gene is transcribed and the 25 UNA spliced. Media from the transfected cells is positive in assays for XL-3-like biological activity in the human bone narrow assay and the CML assay as described below. Northern blot analysis with a gibbon cDNA probe indicates the presence of a single 1 kb mRNA which is obtained from these cells and is 30 the sane size as RNA obtained from peripheral blood lymphocytes, as described below. cDNA is synthesized from the mRNA by standard procedures and a clone identified which has CML activity. cDNA for a novel IL-3-like growth factor is isolated therefrom. 23 EXAMPLE III A Human IL-3-Like Growth Factor The cDNA sequence of Table II encoding a human IL-3-like polypeptide may also be obtained in ways other than that described in Example II. For example, the sequence of Table II may be chemically synthesized according to procedures well known to those skilled in the art. One such chemical synthetic method involves reconstructing the gibbon IL-3 gene to provide the human IL-3 coding sequence. The first amino acid difference between the mature forms of the gibbon and human IL-3 protein occurs at amino acid 82. The coding sequence from amino acid 82 in the gibbon IL-3 gene to the 3*-end of the gene can be replaced by chemically synthesized DNA sequences encoding for human IL-3, thereby yielding a functional gene capable of producing human IL-3 in a suitable expression system.

Two unique restriction sites in the gibbon sequence can be used for cloning synthetic sections of DNA: an Asu II site at amino acid 73 and EcoRI at amino acid 125. A DNA "cassette" for insertion into the gibbon gene was synthesized from the Asu II site to the EcoRI by enzymatically providing a DNA duplex of approximately 160 bp from two oligonucleotides which are complementary to each other over 21 base pairs. The complete duplex was formed by extending the complementary region to the ends of the oligonucleotides using deoxynucleoside triphosphates and DNA polymerase I, Klenow fragment. The complete duplex was digested with Asu II and/or EcoRI to yield cohesive ends for subsequent cloning.

A second synthetic DNA "cassette" consists of two oligonucleotides, complementary to each other throughout their length, from the EcoRI site at amino acid 125 to, and including, the termination codon following amino acid 152 at the end of the gene. These oligos were designed with an EcoRI cohesive end and suitable restriction sites or cohesive ends at or just after the termination codon for cloning into different expression vectors. 24 Two sets of these cassettes were synthesized, one set for mammalian expression, the other for bacterial expression responsive to differences in codon usage between prokaryotes and eukaryotes, the low incidence of CpG doublets in eukaryotic 5 genes and retention of, or the need for, different restriction sites for cloning. Such codon preferences are known to those skilled in the art. See, e.g., T. Maruyama et al., Nucl. Acids Res. f 14.:r151 (1986). Exemplary codon changes and cohesive ends synthesized for these cassettes appear in Table III below.

The cassettes are then cloned into the vector, pCSF-MLA, to transform it into a vector bearing the gene encoding the human IL-3-like factor. This resulting vector is then used to express the human factor.

TABLE III I. CODON CHANGES Amino acid * Bacterial expression Mammalian expression 73 CGT 74 CGT 75 CCG 82 CGT 86 AGC 87 CTG CTG 88 CAA CAA 89 AAT 91 AGC 97 CTG CTG 100 CTG CTG 102 CCG 105 CCG 108 ACC ACA 109 GCT 111 CCG 112 ACC ACC 113 CGT AGG 115 CCG 120 GAT 127 CGC AGG 128 CGC 131 ACC ACC 137 CTG CTG 140 GCT GCT 143 CAG CAG 145 ACC ACC 146 ACC ACC 147 CTG CTG 152 TTC TTC 26 TABLE III (cont'd) II. CASSETTE TERMINI Cassette * Bacterial expression I 73 125 arg arg...glu phe arg T CGT...GAA TTC CGT A GCA...CTT AAG GCA Cassette * I Cassette * II Cassette 3 II Mammalian Expression 71 asn leu arg arg. AAC CTT CGA AGG. TTG GAA GCT TCC. 125 .glu phe arg .GAA TCC CGTC .CTT AGG GCAG Bacterial expression 126 152 phe arg phe AA TTC CGC TTC TAG AACTCGAGACTGCA G GCG AAG ATC TTGAGCTCTG Mammalian expression 126 phe arg AA TTC AGG G TCC 152 phe TTC TAG AACTCGAGA AAG ATC TTGAGCTCTTTAA 27 Alternatively, obtaining the cDNA sequence of a human IL-3-like growth factor can involve cloning the cDNA from a tissue source. The gibbon cDNA sequence of Table I was employed as a probe according to T. Haniatis et al., supra and identified peripheral blood lymphocytes as a human source for isolating mRNA encoding this human IL-3-like polypeptide. Poly A* RNA is prepared from the peripheral blood lymphocyte source, converted to cDNA and cloned as either a phage or plasmid cDNA library. A human cDNA clone can be identified by hybridization with the gibbon coding sequence of Table I as a DNA probe and a determination of IL-3-like biological properties.

Additional tissue sources which may also be screened for human IL-3-like cDNA include spleen, liver, thymus, tonsils, kidney, and other fresh tissues available from biopsies and cadavers. Of special interest are cases where the tumor may be responsible for elevated hematopoietic cell counts, e.g., leukemia. Additional sources are the cell lines deposited for public use in depositories, e.g. ATCC, or available through government agencies and certain private sources. Exemplary cell lines include transformed T and B cell lines, and cell lines which are not of hematopoietic origin, but generate hematopoietins.

In order to express this human IL-3-like polypeptide, the cDNA encoding it is transferred into an appropriate expression vector, e.g. pCD or pXM, and introduced into selected host cells by conventional genetic engineering techniques as described above. One mammalian expression system for a biologically active recombinant human IL-3-like polypeptide is stably transformed CHO cells. However, an active polypeptide can be produced intracellularly or extracellularly from E. coli, and other bacteria. Yeast or insect cells may also be employed as expression systems, as described in Example IV.

Another alternative method for expressing this human IL-3-like polypeptide is to employ the Bgl II fragment from lambda CSF-16 containing the complete human genomic gene to construct 28 mammalian cell lines expressing the polypeptide, e.g. as described by PCT W085/20610 for human erythropoietin. In addition, this human genomic gene can be engineered with the appropriate promoter and processing signals for expression in some other 5 heterologous system, e.g. insect promoters for constructing insect cell culture lines. Similarly, this genomic gene may be expressed in yeast or other eukaryotic systems.

EXAMPLE XV Expression of IL-3-like Growth Factors A plasmid, pCSF-MLA, is simply constructed by inserting the gibbon sequence of Table I into Xhol-digested pXM as described above. A plasmid with the human sequence, pSHIL-3-1 is constructed synthetically for mammalian expression as described 15 above in Example III. Another plasmid pY3 is made as described above. Each of these plasmids carrying a primate IL-3-like growth factor is then transformed by conventional techniques into a selected host cell for expression of a polypeptide.

A. Mammalian Cell Expression; To obtain expression of the IL-3-like factors for use in the assays described below, pSHIL-3-1 and pCSF-MLA are transfected onto COS cells. The conditioned medium for the transfected COS cells contained high levels of growth factor activity as 25 described.

The mammalian cell expression vectors described herein may be synthesized by techniques well known to those skilled in this art. The components of the vectors, e.g. replicons, selection genes, enhancers, promoters, and the like, may be 30 obtained from natural sources or synthesized by known procedures. See, Kaufman et al, J. Mol. Biol.. 159;511-521 (1982); and Kaufman, Proc. Natl. Acad. Sci.. U.S.A.. 82:689-693 (1985). Exemplary mammalian host cells include particularly primate cell lines and rodent cell lines, including transformed cell 35lines. Normal diploid cells, cell strains derived from in 29 vitro culture of primary tissue, as well as primary explants, are also suitable. Candidate cells need not be genotypically deficient in the selection gene so long as the selection gene is dominantly acting. For stable integration of the vector DNA, 5 and for subsequent amplification of the integrated vector DNA, both by conventional methods, CHO cells may be employed. t Alternatively, the vector DNA may include all or part of the bovine papilloma virus genome [Lusky et al, Cell, 36:391-401 (1984)] and be carried in cell lines such as C127 mouse cells 10 as a stable episomal element. Other suitable mammalian cell lines include but are not limited to, HeLa, COS-1 monkey cells, mouse L-929 cells, 3T3 lines derived from Swiss, Balb-c or NIH mice, BHK or HaK hamster cell lines.

Stable transformants are then screened for expression of 15 the product by standard immunological or enzymatic assays. The presence of the DNA encoding the variant proteins may be detected by standard procedures such as Southern blotting. Transient expression of the DNA encoding the variants during the several days after introduction of the expression vector DNA into 20 suitable host cells such as COS-1 monkey cells is measured without selection by activity or immunologic assay of the proteins in the culture medium.

One skilled in the art can also construct other mammalian expression vectors comparable to pCSF-MLA and pSKIL-3-1 by, 25 e.g., cutting the DNA sequence of Table I or Table II from the respective plasmids with Xhol and employing well-known recombinant genetic engineering techniques and other known vectors, such as pJL3 and pJL4 [Gough et al-, EMBO J.. 4:645-653 (1585)1 and pMT2 (starting with pMT2-VWF, ATCC $67122; see EP-A 0 253 870. 30 The transformation of these vectors into appropriate host cells can result in expression of the IL-3-like growth factors.

B. Bacterial Expression Systems; Similarly, one skilled in the art could manipulate the sequences of Tables I and II by eliminating or replacing the mammalian regulatory sequences flanking the coding sequences with bacterial sequences to create bacterial vectors for intracellular or extracellular expression of the IL-3-like factors of the invention by bacterial cells. The DNA encoding the factor nay be further nodified as in Exanple III to contain different codons for bacterial expression as is known in the art. Preferably the sequence is operatively linked in-frame to a nucleotide sequence encoding a secretory leader polypeptide permitting bacterial expression, secretion and processing of the mature variant protein, also as is known in the art. The compounds expressed in bacterial host cells may then be recovered, purified, and/or characterized with respect to physiochemical, biochemical and/or clinical parameters, all by known methods.

To construct one such bacterial vector for bacterial expression, a partially synthetic human IL-3-like DNA sequence was constructed from the gibbon cDNA and the synthetic bacterial cassettes described in Example III. This sequence was placed into a Ndel/Xbal digested vector pall81 which is deposited with the ATCC under accession number 40134. The resulting vector pPLHIL—3—181 was transfected into E. coli GL400 and cultured according to the conditions described for GM-CSF in published PCT application 86/00639.

The IL-3-like factor in the E. coli is produced in insoluble inclusion bodies. To solubilize and obtain the protein therefrom, the following procedure is followed. Approximately 50 g of cells in a frozen paste are resuspended in 120 ml of SO mM Tris-HCl, pH7.5, 0.1 mM phenyl-methylsulphonylflouride [PMSF] and 2 mM dithiothreotol [DTT] (Buffer A). The cells are disrupted by passage through a French press or a Matin Gaulin valve at 10,000 psi or greater. These disrupted cells are then centrifuged at 20,000 x G for 30 ninutes to pellet the cell debris, which includes the inclusion bodies.

The pellet is resuspended in 55% sucrose in Buffer A by passage through the French press, and again centrifuged at 30,000 ♦(Trade mark) 31 x G for 3 0 minutes. The pellet containing IL-3-like factor inclusion bodies is resuspended in 55% sucrose in Buffer A and layered onto a step gradient of 60, 65 and 70% sucrose. The gradient is centrifuged at 150,000 x G for two hours. IL-3-5 like factor inclusion bodies sediment in to the 65% layer, which is collected.

To reconstitute and refold the now approximately 80% pure IL-3-like factor, these inclusion bodies are resuspended at 2-3 mgs protein per milliliter in 8tt urea. The urea solution 10 containing the protein is diluted with 50mM TrisHCl, pH 8.0, 0.1 mM PMSF, 2mM DTT and 0.1 mM ethylenediaminetetraacetic acid [EDTA] (Buffer B) to a final concentration of 3M urea (in which the IL-3 concentration is approximately 1 ug/ml). A reducing/ oxidizing buffer containing 6mM reduced glutathioneand .6 mM 15 oxidized glutathione is added to the urea solution and incubated at 20 degrees centigrade for two hours. The 3M urea solution is dialyzed against Buffer B overnight to remove the urea. The IL-3 protein solution is then centrifuged to remove any precipitate. At this stage the IL-3-like factor is refolded 20 and about 85% pure.

Refolded IL-3-like factor is dialyzed against 50 mM MES buffer at pK6.0, containing 0.1 mM EDTA and applied onto a column of DEAE-Sepharose equilibrated in the same buffer. IL-3-like factor is in the flow-through of the DEAE at approximately 25 99% purity. This step also removes any pyrogens. The pH of IL-3 from DEAE flow-through is adjusted to 5.0 with 200 mM sodium acetate buffer at pH4.0. The IL-3-like factor is applied to a sulphonyl propyl-Sepharose* column and IL3-like factor binds to the SP-Sepharose*and is eluted with the sodium acetate 30 containing buffer. At this stage the IL-3-like factor is pure and refolded correctly. In the CML assay, this human .IL-3-like factor has a specific activity of between l to 3 X 107 CML units/mg.

Similarly, the coding sequence of Table I or that of Table 35 ii could be cut from pCSF-MLA or pSHIL-3-1, with Xhol and 32 further manipulated (e.g., ligated to other known linkers or modified by deleting non-coding sequences therefrom or altering nucleotides therein by other known techniques). The modified IL-3-like coding sequence could then be inserted into a known 5 bacterial vector using procedures such as described in T. Taniguchi et al., Proc. Natl Acad. Sci. PSA. 22:5230-5233 (1980). This exemplary bacterial vector could then be transformed into bacterial host cells and the XL-3-like factor expressed thereby. For a strategy for producing extracellular expression 10 of IL-3-like factors in bacterial cells, see, e.g. European patent application EPA 177,343.

C. Insect Cell Expression; Similar manipulations can be performed for the construction 15 of an insect vector [See, e.g., procedures described in published European patent application 155,476] for expression in insect cells. A yeast vector could also be constructed employing yeast regulatory sequences for intracellular or extracellular expression of the proteins of the present invention by yeast 20 cells. [See, e.g., procedures described in published PCT application WO 86 00639 and European patent application EP 123,289.] EXAMPLE V Construction of CHO cell lines expressing high levels of 25 Primate IL-3-like Growth Factor One method for producing high levels of the novel primate family of IL-3-like polypeptides of the invention from mammalian cells involves the construction of cells containing multiple copies of the heterologous IL-3-like gene. The heterologous 30 gene can be linked to an amplifiable marker, e.g., the dihydrofolate reductase (DHFR) gene for vhich cells containing increased gene copies can be selected for propagation in increasing concentrations of methotrexate (MTX) according to the procedures of Kaufman & Sharp, J. Mol.Biol.. (1982) supra. 35 This approach can be employed with a number of different cell 33 types.

For example, pY3 contains a human IL-3-like gene in operative association with other plasmid sequences enabling expression thereof. pY3 and the DHFR expression plasmid pAdA26SV(A)3 5 (Kaufman & Sharp, Mol. Cell Biol.. 2(9) 11598-1608 (1983) can be co-introduced into DHFR-deficient CHO cells, DUKX-BII, by calcium phosphate coprecipitation and transfection. Alternatively, the gene may be introduced into pMT2 as previously mentioned and the resultant vector used in place of pY3 and pAdA26SV(A) 3. 10 DHFR expressing transformants are selected for growth in alpha media with dialyzed fetal calf serum, and subsequently selected for amplification by growth in increasing concentrations of MTX (sequential steps in 0.02, 0.2, 1.0 and 5uM MTX) as described in Kaufman et al., Mol. Cell Biol. 5:1750 (1983). Transformants 15 are cloned, and biologically active IL-3-like polypeptide expression is monitored by CML assays. IL-3-like polypeptide expression should increase with increasing levels of MTX resistance. Similar procedures can be followed to produce other members of this family of IL-3-like polypeptides, 20 including the gibbon IL-3-like polypeptides.

EXAMPLE VI Biological Activities of an IL-3-like Polypeptide The following assays were performed using both the gibbon 25 polypeptide and the human polypeptide as representative members of the novel family of primate IL-3-like polypeptides of the present invention. However, other members of the family will exhibit IL-3-like biological properties in these same assays or in other assays depending on the number of IL-3-like biological 30 properties displayed by the individual polypeptide.

A. CML Assay The CML assay was performed essentially according to procedures described in Blood. 63(4) :904-lll (1984). A stock 35 of cells were obtained from a frozen bag of peripheral blood 34 from a CML patient in stable phase. This bag was thawed and refrozen into 500 aliguots of 15 x 10® cells/vial. These cells, "CML 8-3", were used to test for the IL-3-like activity of the IL-3-like polypeptides. One vial is thawed quickly at 5 37*C the day before the assay is set up. The contents of the vial are then transferred to a 15 ml tube and washed 2 times with 5% Hi Human AB Serum in RPMI (GIBCO,RPHl 1640) [HAB/RPMI]. The cells are incubated overnight in 5% HiHAB/RPMI at 5% C02 and 37°C. The following day the cells are removed from culture, 10 ficolled, washed, recounted and set aside. 100 ul of 10% HIFCS2/RPMI medium containing the material to be assayed is plated in each well of a microtiter plate. The cells prepared above are spun down and resuspended at a concentration of 1.3 to 2 xlO5 cells/ul in 10% HIFCS/RPMI. 100 15 uls of cells are plated in each well and incubated in the presence or absence of anti-human GMC5F antibodies at 37 "C in 5% C02 for 48 or 72 hours. Thereafter 0.5 uCi 3.H-thymidine is added per well and the wells are incubated for 6 hours at 37*C. Cells are harvested using a filtration manifold device onto GFC Type 20 C filter paper (Schleicher-Schuller), washed with phosphate buffered saline and dried. Filters are then iamersed in scintillation fluid and counted for 3H uptake.

Based on the thymidine uptake measurement, both the gibbon IL-3-like growth factor and the human IL-3-like growth factor 25 are active in this assay in stimulating the proliferation of leukemic blast cells.

B. Bone Marrow Assays Human bone marrow assays, employing non-adherent bone 30 marrow cells, were performed as described in G.G. Wong, et al., suora. Conditioned media for both the gibbon and human factors was found to be active in this assay, producing small colonies of apparently granulocytic-type lineage. Also produced upon morphological examination of stained agar cultures were 35 macrophage, granulocyte-macrophage and eosinophil colonies.

When this assay is performed in the presence of erythropoietin, the ability of conditioned medium to support the growth of erythroid progenitor cells is demonstrated by the production of red blood cell colonies. When GM-CSF was compared with the 5 IL-3-like polypeptide in the human bone marrow assay, IL-3-like polypeptide supported the formation of more colonies than GM-CSF , when both polypeptides were in the presence of erythropoietin. The majority of colonies supported by GM-CSF were single lineage; while the polypeptide of the present 10 invention supported the formation of multi-lineage colonies. Similarly, in blast cell colony formation assays, the IL-3-like polypeptide produced greater numbers of blast cell colonies of multiple lineages. GM-CSF in the same assay produced very few secondary colonies.

C. KG—1 Cell Assay The KG—1 assay was performed as described in G. G. Wong et alr supra. The gibbon IL-3-like polypeptide member of the novel primate family of IL-3-like growth factors produced 20 according to the present invention was active in this assay.

D. Miscellaneous Assays In an antibody-dependent cell-mediated cytotoxicity assay, the IL-3 like polypeptide of the present invention 25 stimulated eosinophils to kill antibody-coated tumor target cells in a dose-dependent manner. The polypeptide additionally stimulated eosinophils to phagocytose serum-opsonized baker*s yeast, and to directly stimulate superoxide anion production by eosinophils. In preliminary studies in which IL-3-like factors 30 of the invention are infused into healthy monkeys and the white counts observed, reproducible increases in both platelet count and number of eosinophils have been observed. These preliminary results have been observed for both the human and gibbon IL-3-like factors.

* (Trade Mark) 36 EXAMPLE VII Purification of TL-3-Like Polypeptide from COS Cell Conditioned Medium The following procedures are presently employed to obtain 5 homogeneous IL-3-like protein from COS cells, as described in Example IV above.

A. ion Exchange COS cell conditioned media [DMEM, 0.5%FBS in roller bottles 10 at a total protein concentration of 200 ug/ml] contained the human IL-3-like polypeptide at a concentration of approximately 2-3 ug/ml. The media is diluted with water until the conductivity is t-ess than 8.0 ns/cn2. An ion exchange cartridge [QAS Zeta Prep* is equilibrated at 4 degrees centigrade with approximately 15 500 mis 0.1M Tris-Cl, pH8.0 and then zwo liters of 40 nM Tris-Cl, pH7.4. Media was loaded at 40 ml/minute, and the urJDour.d fraction collected. The cartridge was washed with 40mM Tris-Cl until no further activity washed off. To obtain bench-scale amounts of IL-3-like protein, the unbound fraction as 20 concentrated on a diaf iltration unit membrane [Aiaiccn YM-10} .

An alternative to this concentration step for larger scale purification of an IL-3-like protein is to acidify the QAE-Zeta Prep* unbound fraction with 1M glacial acetic acid to a pH of 4.5. Media is loaded at 4 0ml/minute onto a sulfonylpropyl 25 (SP)-Zeta Prep, which is equilibrated at 4 degrees centigrade with approximately 500 mis of *20mM sodium acetate, at pK4.5. 'The cartridge is' washed with 20mM sodium acetate and the bound fraction eluted with 20mM sodium acetate and 0.25 to 0.5M sodium chloride. This fraction is neutralized with 1M Tris-Cl, 30 pH8.0 to pH7.4 and Tween-20 is added to 0.05% final concentration.

B. Lentil Lectin Column A lentil lectin column was equilibrated in 20 mM Tris, pH7.4, 0.05% Tween*-20 at 4 degrees centigrade' (Buffer I] and 35 then loaded at 1 column volume per hour. The column was washed 37 with Buffer I to remove non-specifically-bound protein and then bound protein was eluted with Buffer I plus 0.2H alpha-methyl-mannopyranoside. The elution fractions were pooled.

C. Reverse Phase HPLC This preparation of IL-3-like polypeptide was subjected to reverse phase HPLC at room temperature as described below. The IL-3-like polypeptide preparation was injected onto a RP HPLC column [C4 Vydac] equilibrated in 100% Buffer A. Buffer A was 0.1% trifluoroacetic acid [TFA] in water and Buffer B was 0.1% TFA in 95% acetonitrile. The gradient was 0.2%/minute from 45 to 70% Buffer B. The fractions pooled from this gradient were 46.8% B to 47.5% Buffer B. These fractions were speed vacuumed to remove the acetonitrile. In a second reverse phase HPLC step, Buffer A was 0.15%HFBA in water and Buffer B was 0.15% heptafluorobutyric acid [HFBA] in 95% acetonitrile. The gradient was 0.2%/minute from 45 to 70% Buffer B. The fractions pooled from this step were 49% to 51 % Buffer B. This fraction eluting from the HPLC was pyrogen free.

EXAMPLE VIII Analyses of IL-3-Like Polypeptides A. SDS-PAGE Following the procedure of R.J. Kaufman and P.A Sharp., J. Mol. Biol. 159:601-621 (1982), 35S methionine is metabolically incorporated into the polypeptides made by COS cells transfected with pCSF-MLA and COS cells transfected with pY3. SDS polyaerylaaide gel electrophoresis (reducing conditions) [U.K. Laeaali, Nature £22:680-685 (1970)] of labeled proteins secreted by the transfected COS-1 cells revealed a distribution Of polypeptides with apparent molecular masses ranging between 14kd and 3 5kd for both the gibbon and human factors. This distribution was absent in the mock transfected control sample.

More specifically, CHO-produced human IL-3-like factor revealed * (Trade Mark) 38 a distribution of between 21 to 32kd, illustrating nore glycosylation than the COS cell produced human factor vith a distribution primarily between 21 and 28kd.

With silver stain after the purification procedures cf 5 Example VI, two major bands of average molecular weights 21,000 and 25,000 appeared in approximately equal amounts for both factors. The differences in the two bands is presently attributed to differences in N-linked glycosylation. B. Isoelectric Focusing 10 Native isoelectric focusing of the purified polypeptides of Example VII reveal four species for both the gibbon and human polypeptides, which range in Pi value between pH 6.0 ar.d pH7.6.

C. Supercse 6 Fast Protein Liquid Chromatography The purified reaction from KPLC was run in a gel filtra-icn * column [Superose 61 m 20mM Tris, pH7.4, 2 00 mM NaCl, and 0.05% Tween-20? This column run revealed one sharp peak of apparent molecular weight of 43kd for both factors.

D. Specific Activity in CML Assay The specific activity of an exemplary gibbon IL-3-like factor in the CML assay described above falls within the range of 2X10^ to 1X107 dilution units/mg of polypeptide, with an 25 average of 8X106 dilution unit/mg. The bacterially-prcduced human polypeptide described in Example IV (B) was found to hlave a specific activity of 1 to 3X107 dilution units per ng of polypeptide. CHO-produced human IL-3-like factor has a specific activity of about 2 to 3X106 units per mg protein in this 30assay. cos-produced human IL-3-like factor has a specific activity of about 1 to 2X107 units per mg. A dilution unit (or CML unit) is defined as that dilution of the factor which gives one-half maximal stimulation in the CML assay.

E. N-Teminal Analysis Analysis of the N-terminal sequence of the gibbon polypeptide 39 was made using automated Edman degradation which demonstrated a level of purity of the factor of 98%.

F. N-Glvcanase Treatment 5 The human and gibbon factors produced in COS cells were treated with the enzyme N-glycanase, which digests the N-linked carbohydrate moieties. Each factor was shown to be purified by this method. The 14-35kd smear of each factor on the gels was reduced to a single band of 15kd for the gibbon factor and 20.5kd 10 for the human factor. 40

Claims (28)

1.A DNA sequence that encodes a polypeptide comprising one or more of the mature peptide sequences as shown in Table I or Table II wherein amino acid 27 is Serine and which possesses at least one of the biological .. properties of primate IL-O, said biological properties being selected from the group consisting of : (a) the ability to support the growth and differentiation of primate progenitor cells committed to erythroid, lymphoid and myeloid lineages; (b) the ability to stimulate granulocytic colonies and erythroid bursts in a standard human bone marrow assay; (c) the ability to sustain the growth of primate pluripotent precursor cells; and (d) the ability to stimulate primate chronic myelogenous leukemia (CML) cell proliferation in the CML assay.

2.A DNA sequence capable of hybridizing under relaxed or stringent conditions, or which would be capable of hybridizing under said conditions but for the degeneracy of the genetic code, to a DNA sequence selected from the group consisting of : (a) . the DNA sequence of Table I; (b) the DNA sequence of Table II, wherein the codon for amino acid 27 is TCC; (c) the Xhol insert in pXM (ATCC 67154) ; and (d) the BamHI or Bglll genomic insert in bacteriophage lambda M13 cloning vector mp9 (ATCC 40246); 41 said DNA encoding a polypeptide having at least one biological property of primate IL-3, selected from the group consisting of : (i) the ability to support the growth and differentiation of primate progenitor cells committed to erythroid, lymphoid and myeloid lineages; (ii) the ability to stimulate granulocytic colonies and erythroid bursts in a standard human bone marrow assay; (iii) the ability' to sustain the growth of primate pluripotent precursor cells; and (iv) the ability to stimulate primate chronic myelogenous leukemia (CML) cell proliferation in the CML assay.

3.The DNA sequence of claim 1 or 2 wherein the DNA comprises a cDNA.

4.The DNA sequence according to any one of claims 1 to 3 which is a human or gibbon DNA sequence.

5.A recombinant vector containing a DNA sequence according to any one of claims 1 to 4.

6.The recombinant vector of claim 5, wherein said DNA sequence is in operative association with selected regulatory sequences.

7.A host cell containing a vector according to claim 5 or 6.

8.The host cell according to claim 7 which is a mammalian cell, a bacterial cell or a yeast cell.

9.A polypeptide or protein encoded by a DNA sequence according to any one of claims 1 to 4. 42

10. The protein of claim 9 which has the amino acid sequence given in. Table I or in Table II, wherein the amino acid sequence of Table II. contains the amino acid Serine at position 27, said protein being optionally 5 devoid of the Methionyl residue at the N-terminus.

11. The polypeptide or protein of any one of claims 9 or 10 which has a molecular weight of about 14,000 to about 35,000 as determined by reducing SDS polyacrylamide gel 10 electrophoresis.

12. A method for the production of a polypeptide according to any one of claims 9 to 11 which involves culturing a host cell of claim 7 or 8. 15

13. A therapeutic composition comprising one or more of the polypeptides or proteins of any one of claims 9 to 11 in admixture with a pharmaceutical ly acceptable carrier. 20

14. The therapeutic composition of claim 13 which further comprises at least one other hematopoietin, interleukin or growth factor. 25

15. The therapeutic composition according to claim 14, wherein said hematopoietin is GM-CSF, G-CSF, CSF-1 or erythropoietin. 30

16. The therapeutic composition according to claim 14, wherein said interleukin is IL-1, IL-2 or IL-4.

17. Use of a polypeptide according to any one of claims 9 to 11 for the preparation of a therapeutical composition for the treatment of a deficiency in the 35 level of hematopoietic cells, wherein said deficiency 43 is leukopenia, thrombocytopenia, anemia, B cell deficiency, T cell deficiency, viral infection.

18. The use according to claim 17, wherein said disease 5 state comprises immune cell or hematopoietic cell deficiency following a bone marrow transplantation.

19. The use according to claim 17 or 18 for the preparation of a therapeutic composition which additionally 10 comprises at least one other hematopoietin, interleukin or growth factor.

20. The use according to claim 19, wherein said hematopoietin is GM-CSF, G-CSF, CSF-1 or 15 erythropoietin.

21. The use according to claim 19, wherein said interleukin is IL-1, IL-2 or IL-4. 20 25 35

22. A DNA sequence according to claim 1 or 2, substantially as hereinbefore described.

23.3. A recombinant vector according to claim 5, substantially as hereinbefore described.

24.4. A host cell according to claim 7, substantially as hereinbefore described.

25.5. A polypeptide or protein according to claim 9, 30 substantially as hereinbefore described.

26.6. A method according to claim 12 for the production of a polypeptide, substantially as hereinbefore described and exemplified.

27. A therapeutic composition according to claim 13, substantially as hereinbefore described.

28. Use according to claim 17, substantially as 40 hereinbefore described. ANNE RYAN & CO., Agents for the Applicants.