Figure 2

Contribution of TLRs to mucous membrane immunity. Pattern-recognition receptors, including toll-like receptors (TLRs) and nucleotide-binding oligomerization domain- (NOD)-like receptors (NLRs), are expressed by most IEC. TLR ligation leads to the recruitment of adaptor proteins, such as TIR domain-containing adaptor protein inducing interferon (TRIF), MyD88 (myeloid differentiation primary-response gene 88) and subsequent activation of several signaling modules, including mitogen-activated protein (MAP) kinase pathways NF-κB. Activation of PRRs by helminth infection advances a cascade of signaling events that results in the expression of pro-inflammatory cytokines and chemokines.