Toll-like receptor (TLR)2 and TLR3 synergy and cross-inhibition in murine myeloid dendritic cells.

Toll-like receptors (TLRs) play an important role in the innate recognition of pathogens by dendritic cells (DCs) and in the induction of immune responses. Few studies have been devoted to address the impact of TLR2 (a fully MyD88-dependent receptor) and TLR3 (a fully TRIF-dependent receptor) co-activation on DC functions, especially in the mouse system. Using canonical agonists, we show that TLR2 acts in concert with TLR3 to induce the synthesis of inflammatory cytokines (TNF-alpha, IL-6), of some IL-12 family members (IL-12p40, IL-12p23, IL-27p28) and of the Notch ligand Delta-4 by mouse DCs.