ENDOGENOUS GAMMA-INTERFERON AND INTERLEUKIN-10 IN BRUCELLA-ABORTUS-2308 INFECTION IN MICE

CD-1 mice intravenously infected with the virulent Brucella abortus 23 08 strain simultaneously produce significant levels of gamma interfero n (IFN-gamma) and interleukin-10 (IL-10) in their spleens between the second and eighth day post-infection with no production of interleukin -4 (IL-4). Endogenous synthesis of IL-10 does not affect the productio n of IFN-gamma in this organ, while the production of both cytokines d uring this period of time is accompanied by a statistically significan t increase (P < 0.001) in the number of colony forming units (cfu) of B. abortus 2308 present in the organ. These findings suggest that alth ough the endogenous synthesis of IL-10 apparently does not affect IFN- gamma production, it may affect the effector functions of macrophages to control intracellular brucellae. Production of the Th1 cytokine IFN -gamma during B. abortus 2308 infection is also associated with a spec ific IgG3 and IgG2a response against the B. abortus 2308 lipopolysacch aride (S-LPS) antigen.