We cloned the canine interleukin-12 (IL-12) subunit cDNA. Canine IL-12
exhibited sequence homology to the known sequences of human, mouse, a
nd bovine genes at nucleotide and amino acid levels. Cotransfection of
the p35 and p40 subunits of canine IL-12 cDNA clones into COS-1 cells
resulted in the secretion of IL-12, which supported proliferation of
the stimulated canine lymphocytes, promoted induction of canine interf
eron-gamma (IFN-gamma) from canine lymphocytes, and showed antitumor e
ffect in vitro. The cloned canine IL-12 will be useful for canine ther
apeutic applications.