IN-VITRO EFFECTS OF LIVE AND KILLED BRUCELLA-ABORTUS ON BOVINE CYTOKINE AND PROSTAGLANDIN E(2) PRODUCTION

Live and gamma-irradiated-killed Brucella abortus strain 2308 increase d interleukin 1 (IL-1), but not interleukin 2 (IL-2), interferon-gamma (IFN-gamma), or prostaglandin E(2) (PGE(2)) production when incubated with normal bovine peripheral blood mononuclear cells (PBMC). Live B. abortus was more effective than killed B. abortus in stimulating IL-1 production by normal PBMC. Both live and killed B. abortus were equal ly effective in suppressing IL-2 and IFN-gamma production by Concanava lin A-stimulated PBMC. Incubation of PBMC with the cyclo-oxygenase inh ibitor, indomethacin, blocked PGE(2) synthesis, but did not further en hance IL-1 production or prevent suppressed IL-2 and IFN-gamma product ion that was induced by live and killed B. abortus. These results sugg est that B. abortus-induced suppression of IL-2 and IFN-gamma producti on did not appear to be mediated by the suppressive prostaglandin, PGE (2), or other cyclo-oxygenase metabolites.