FIGURE 9.

Schematic diagram demonstrating signaling pathways involved in HIV Tat-mediated induction of CXCR3 expression in human monocytes. HIV Tat-mediated TLR4 activation results in phosphorylation of TBK1 and subsequently induces phosphorylation and nuclear translocation of IRF3 which, leading, in turn, increases the binding of IRF3 and CXCR3 promoter and subsequently enhance CXCR3 expression. Increased CXCR3 ultimately leads to increased CXCL10-mediated monocyte transmigration into the brain.