Immunostimulatory effects of human recombinant interleukin-12 on peripheral blood mononuclear cells from normal dogs

Interleukin-12 (n-12) plays a pivotal role in regulating cellular immune re sponses involving autoimmunity. infectious disease. and cancer. Human recom binant (hr) IL-12 is being evaluated for therapy of human cancer. We invest igated the potential of hrIL-12 to activate canine peripheral blood mononuc lear cells (PBMC) using proliferation and cytotoxicity as readouts. Human r IL-12 caused increased proliferation of PBMC, and enhanced lysis of allogen eic canine tumor targets mediated by PBMC from normal dogs in vitro. In add ition, antibody-dependent cellular cytotoxicity (ADCC) mediated by canine P BMC was enhanced by hrIL-12. These results indicate that hrIL-12 is recogni zed by canine immune cells, triggering a number of immune responses in cani ne PBMC, that may be important for immunotherapy of canine cancer. Informat ion from this investigation provides impetus for evaluation of the effects of hrIL-12 on PBMC from tumor-bearing dogs and should be helpful in the dev elopment of hrIL-12 as an immune cell activator in vivo in the dog. (C) 199 9 Elsevier Science B.V. All rights reserved.