B-CELL KNOCKOUT MICE ARE RESISTANT TO MUCOSAL AND SYSTEMIC CANDIDIASIS OF ENDOGENOUS ORIGIN BUT SUSCEPTIBLE TO EXPERIMENTAL SYSTEMIC CANDIDIASIS

Germfree J(H)D mice, which lack functional B cells and antibodies, wer e as resistant to orogastric and disseminated candidiasis of endogenou s origin as were immunocompetent controls. Newborn J(H)D mice, in cont rast to adult mice, were resistant to alimentary tract colonization by Candida albicans for 5-7 days after birth. C. albicans-colonized J(H) D mice were more resistant to intravenous challenge with C. albicans a nd had greater splenocyte proliferative responses to C. albicans antig ens than did germfree mice or conventional controls. Thus, innate and acquired T cell-mediated immune responses induced after oral immunizat ion are sufficient to protect J(H)D mice from mucosal and systemic can didiasis of endogenous origin; however, functional B cells may be requ ired to protect mice from a primary intravenous challenge with C. albi cans.