Involvement of RP 105 and Toll‐Like Receptors in the Activation of Mouse Peritoneal Macrophages by Staphylococcus aureus

Staphylococcus aureus is the aetiological agent of many hospital‐ and community‐acquired infections. Toll‐like receptor 2 ( TLR 2) has been shown to play a crucial role in the host defence against S. aureus infection. The aim of this study is to investigate the roles of the heterogeneous TLR family proteins TLR 2, TLR 4 and RP 105 during S. aureus infection. Peritoneal macrophages from mice were exposed to S. aureus . Their production of inflammatory cytokines and chemokines, their expression of cell‐surface markers and interactions between TLR 2, TLR 4 and RP 105 were assessed in the presence or absence of inhibitory antibodies against TLR 2, TLR 4/ MD ‐2 and RP 105/ MD ‐1 complexes. Our results demonstrate that not only TLR 2 but also TLR 4 and RP 105 are involved in the response of macrophages to S. aureus , that TLR 2, TLR 4 and RP 105 physically interact with each other during S. aureus infection, and that TLR 2, TLR 4 and RP 105 both cooperate and play unique roles in the production of inflammatory cytokines ( TNF ‐α, IL ‐12p40 and IL ‐10) and chemokine ( RANTES ) by macrophages after S. aureus infection. This study characterizes the important roles that TLR 2, TLR 4 and RP 105 play in host resistance against S. aureus infection.