title: Cloning and expression of a cDNA encoding ovine interleukin 7.
abstract: Using the polymerase chain reaction (PCR) and primers based on regions of homology between the human and murine interleukin 7 (IL-7)-encoding cDNAs, we have amplified an ovine (ov) IL-7 cDNA from reverse-transcribed RNA extracted from concanavalin A (Con A)-activated ovine lymph-node cells. The nucleotide sequence of the cDNA and the predicted amino acid (aa) sequence showed significant homology to those of the human and murine molecules. The ovIL-7 cDNA encodes a 176-aa polypeptide that, based on analysis of murine IL-7, is processed to a protein of 151 aa. The cDNA was demonstrated to encode a protein with IL-7 biological activity. Supernatants from COS or CHO-K1 cells transfected with an expression vector containing the ovIL-7 cDNA were able to synergise with a suboptimal level of Con A to induce proliferation of ovine thymocytes. In addition, both supernatants were able to induce thymocyte proliferation, albeit at a reduced level, in the absence of Con A. Further experiments demonstrated that for induction of ovine thymocyte proliferation, recombinant (re)-ovIL-7 was able to synergise with re-human (h) IL-2 but not re-hIL-6 or tumor necrosis factor-alpha (re-hTNF alpha).
authors.affiliation: Centre for Animal Biotechnology, School of Veterinary Science, University of Melbourne, Parkville, Australia.
authors.forename: G J
authors.initials: GJ
authors.lastname: Barcham
authors.forename: A E
authors.initials: AE
authors.lastname: Andrews
authors.forename: A D
authors.initials: AD
authors.lastname: Nash
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002455:Cell Division / Q000187:drug effects; D003208:Concanavalin A / Q000494:pharmacology; D018076:DNA, Complementary / Q000235:genetics; D004357:Drug Synergism; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology; D015851:Interleukin-7 / Q000096:biosynthesis / Q000235:genetics* / Q000494:pharmacology / Q000502:physiology; D008198:Lymph Nodes / Q000737:chemistry; D051379:Mice; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000494:pharmacology; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D012756:Sheep / Q000235:genetics*; D013045:Species Specificity; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D018076:DNA, Complementary; D007376:Interleukin-2; D015850:Interleukin-6; D015851:Interleukin-7; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D003208:Concanavalin A