The adjuvant effect of a single dose of interleukin-12 on murine immune responses to live or killed Brucella abortus strain Rb51

This study was designed to determine if a single 0.5 mu g administration of recombinant murine interleukin-12 (IL-12) would influence immune responses of mice vaccinated with live or killed Brucella abortus strain RB51 (SRB51 ), Mice were vaccinated intraperitoneally,vith 5 x 10(8) cfu of live or gam ma-irradiated SRB51 bacteria alone, or in combination with 0.5 mu g of IL-1 2, Control mice received saline or 0.5 mu g of IL-12, Serologic responses a nd spleen weights after vaccination were greater in mice vaccinated,vith li ve SRB51 when compared to mice receiving killed SRB51 or control treatments . Administration of a single dose of IL-12 as a vaccine adjuvant did not in fluence immune responses, clearance of live SRB51, or resistance against B, abortus strain 2308 (S2308) challenge, The results of this study suggest t hat a single administration of 0.5 mu g of IL-12 at the time of vaccination does not have significant adjuvant effects on vaccine-induced immune respo nses against live or killed Brucella.