Immunomodulatory effects in vivo of recombinant porcine interferon gamma on leukocyte functions of immunosuppressed pigs.

Immunological parameters of porcine peripheral blood mononuclear cells after in vivo injections of recombinant porcine interferon gamma (rPoIFN gamma) were studied in pigs immunosuppressed by dexamethasone (6 mg/kg body weight in a single injection). A 2-d period of rPoIFN gamma injected alone and intramuscularly at a dose of 1 microgram/kg body weight increased interleukin 1 (IL1) production (P less than 0.05). Recombinant porcine IFN gamma also reversed the immunosuppressive effects of dexamethasone on: i), lymphocyte responsiveness to mitogens: PHA (P less than 0.03), ConA (P less than 0.053); ii), IL1 production; and iii), IL2 production (P less than 0.05). However, rPoIFN gamma had no effect on neutrophilia induced by dexamethasone. These data show that rPoIFN gamma modulates leukocyte functions of pigs in vivo.