B and CD4+ T-cell expression of TLR2 is critical for optimal induction of a T-cell-dependent humoral immune response to intact Streptococcus pneumoniae.

摘要: TLR2(-/-) mice immunized with Streptococcus pneumoniae (Pn) elicit normal IgM, but defective CD4(+) T-cell-dependent type 1 IgG isotype production, associated a largely intact innate immune response. We studied the phosphorylcholine (PC)-specific IgG3 versus T-cell-independent IgM response to Pn determine whether TLR2 signals directly via adaptive system. Pn-activated BMDC have only modest defect in cytokine secretion, undergo maturation, and when transferred into naive WT anti-PC response, relative BMDC. synergizes BCR TCR signaling for DNA synthesis purified B CD4(+)T cells, respectively, is cells lacking TLR2. primes T-cell IFN-gamma recall Notably, RAG-2(-/-) or athymic nude mice, each IgG3, contrast cells. These data are first demonstrate major role B-cell expression of eliciting an anti-bacterial humoral