To ascertain the component(s) of TLR2-mediated signal transduction pathways responsible for B7-H3-amplified inflammatory response during pneumococcal meningitis, we first examined the impact of B7-H3 on expression of TLR2, MyD88, IRAK1, TIRAP, and TRAF6 in brain tissues of S. pneumoniae-infected mice. Here, IRAK1 is linked to pneumococcal meningitis.