Cellular and Humoral Mechanisms Involved in the Control of Tuberculosis

Figure 2

TLRs signaling pathways involved in the recognition of Mtb structures.TLR receptors can recognize several conserved molecular patterns of the mycobacteria cell wall. Diacylated or triacylated proteins as well as LPS are recognized by membrane receptors (TLR1, TLR2, TLR6, and TLR4), whereas bacterial unmethylated CpG DNA can be recognized by endosomal TLR9. MyD88 adaptor is a central component in TLR signaling whose downstream signaling cascade leads to the activation of NF-kB and AP-1 transcription factors and to the production of inflammatory cytokines. Signaling through TRIF adaptor molecule activates IRF-3 transcription factor inducing IFN-β secretion.