The characterisation of a cervine immunoregulatory cytokine, interleukin 12.

The cloning, sequencing, and production of cervine interleukin-12 is described. The cervine IL-12 p35 subunit coding sequence is 666 bp long and has highest homology to bovine p35 (94%), followed by human (79%), then murine (57%). The cDNA codes for a 221 aa long protein with predicted molecular weight of 24,902 Da. The cervine p40 subunit has a coding sequence of 984 bp and shows 96% homology to bovine, 85% homology to human, and 65% homology to murine p40 respectively. Cervine p40 cDNA codes for a 327 aa long protein with a predicted molecular weight of 37,461. Both subunits were inserted into a recombinant baculovirus that was then used to produce cervine IL-12 in Trichoplusia ni cells. Interleukin-12 was secreted into the culture medium and was biologically active as measured by proliferation of mitogen sensitised peripheral blood lymphocytes and the induction of interferon-gamma transcription in peripheral blood lymphocytes.