ROLE OF IMMUNE-RESPONSES TO A GROEL HEAT-SHOCK-PROTEIN IN PREVENTING BRUCELLOSIS IN MICE VACCINATED WITH BRUCELLA-ABORTUS STRAIN RB51

Resistance to infection with virulent Brucella abortus strain 2308 and antibody and lymphocyte proliferative responses to a recombinant 60 k Da B. abortus GroEL hear shock protein were measured in mice vaccinate d with attenuated B. abortus strain RB51. Mice at 12-20 weeks after va ccination with 5 x 10(8) colony forming units (CFU) of strain RB51 had increased resistance to infection with strain 2308 and increased anti body and lymphocyte proliferative responses to GroEL following challen ge infection with 2308. However, these mice at 12-20 weeks after vacci nation did not have greater resistance to infection than mice vaccinat ed with 5 x 10(6) CFU of strain RB51. which had no increased antibody or lymphocyte proliferative response to GroEL. These results indicate that mice vaccinated with strain RB51 can have antibody and cell-media ted. immune responses to GroEL during infection with virulent strain 2 308, although neither response appeared to have an essential role in v accine-induced immunity to brucellosis.