Are B lymphocytes of importance in severe Staphylococcus aureus infections?

To investigate the role of B cells in experimental, superantigen-mediated S taphylococcus aureus arthritis and sepsis, me used gene-targeted B-cell-def icient mice. The mice were inoculated intravenously with a toxic shock synd rome toxin 1 (TSST-1)-producing S. aureus strain. The B-cell-deficient and thus agamma-globulinemic mice showed striking similarities to the wild-type control animals with respect to the development of arthritis, the mortalit y rate, and the rate of bacterial clearance. Surprisingly, we found that th e levels of gamma interferon in serum were significantly lower (P < 0.0001) in B-cell-deficient mice than in the controls, possibly due to impaired su perantigen presentation and a diminished expression of costimulatory molecu les. In contrast, the levels of interleukin-4 (IL-4), IL-6, and IL-10 in se rum were equal in both groups. Our findings demonstrate that neither mature B cells nor their products significantly contribute to the course of S. au reus-induced septic arthritis.