G. Splitter et al., T-LYMPHOCYTE MEDIATED PROTECTION AGAINST FACULTATIVE INTRACELLULAR BACTERIA, Veterinary immunology and immunopathology, 54(1-4), 1996, pp. 309-319
Acquired immunity against intracellular bacteria is T cell dependent.
T cells play a major role in protection against intracellular bacteria
, but bacterial antigens recognized by T cells have been studied less
extensively than bacterial antigens recognized by B cells. Using T lym
phocytes from animals immunized against Brucella abortus, we have scre
ened a bacterial genomic library for genes encoding antigens recognize
d by T cells. Lymphocytes that proliferated to B. abortus proteins wer
e characterized for phenotype and cytokine activity. Bovine and murine
lymphocytes recognized common bacterial antigens and possessed simila
r cytokine profiles, suggesting an analogous immune response in these
two animal species. In vivo protection afforded by a particular cell t
ype is dependent on the bacterial antigens presented and mechanisms of
antigen presentation. MHC class I and class II gene knockout animals
infected with B. abortus have demonstrated that protection to B. abort
us is especially dependent on CD8(+) T cells. Knowing the cells requir
ed for protection, vaccines can be designed to elicit the protective s
ubset of lymphocytes. Currently, we are testing several recombinant B.
abortus proteins using different immunization strategies. Finally, ba
cterial genes activated following intracellular phagocytosis are being
examined using a novel, reporter system adapted to B. abortus.