Ovine interleukin 12 has biological activity on ovine and human activated peripheral blood mononuclear cells.
Interleukin 12 (IL-12) is a heterodimeric cytokine composed of two subunits that form the biologically active p70 molecule, and is a potent inducer of the pro-inflammatory cytokine IFN-gamma. In this study the coding sequence for ovine interleukin 12 p35 and p40 subunits was derived by RT-PCR cloning. Ovine p35 and p40 cDNA sequences show a high level of similarity at the nucleic acid and protein levels when compared to corresponding bovine and human sequences. In particular, cysteine residues and N-linked glycosylation sites are conserved between species. Secretion of the IL-12 heterodimer from CHO cells co-transfected with ovine p35 and p40 cDNA was shown by immunoprecipitation of a 60 and 66 kDa protein from transfectant supernatant. In addition, the supernatant from co-transfected cells augmented the proliferation of Con A-activated ovine peripheral blood mononuclear cells (PBMNC). Cross-species activity was shown by the enhancement of proliferation of human phytohaemagglutinin (PHA)-activated PBMNC. Supernatants from co-transfectants of hu p35/ov p40 and ov p35/hu p40, to generate chimeric heterodimers, also demonstrated stimulatory activity. Human and chimeric IL-12-induced proliferation of activated PBMNC was inhibited using an anti-human IL-12 polyclonal antibody, however this antibody showed minimal inhibition of ovine IL-12. This study suggests that ovine IL-12 has biological properties similar to its human counterpart.
Swinburne
S J
SJ
Transplantation Immunology Laboratory, Clinical Development and Research Centre, The Queen Elizabeth Hospital, Woodville, South Australia.
Russ
G R
GR
Krishnan
R
R
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D002417:Cattle; D003001:Cloning, Molecular; D003208:Concanavalin A / Q000494:pharmacology; D017124:Conserved Sequence; D006224:Cricetinae; D017077:Culture Media, Conditioned / Q000378:metabolism; D017931:DNA Primers / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006031:Glycosylation; D006801:Humans; D018664:Interleukin-12 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008969:Molecular Sequence Data; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D012756:Sheep; D014162:Transfection
D017077:Culture Media, Conditioned; D017931:DNA Primers; D018076:DNA, Complementary; D003208:Concanavalin A; D018664:Interleukin-12