Figure 2: Intracellular CXCL10-CXCR3 signaling events in HIV-1 infected cells. Left: HIV infection result in enhanced CXCL10 production. Tat and gp120 directly and/or indirectly induce CXCL10 production. Right: CXCL10 acts on effector cells. The cytoplasmic tail of CXCR3 receptor contains trimeric G protein subunits: Gα constitute regulatory subunit; Gβ and Gγ constitute catalytic subunits. CXCR3A variants cytoplasmic tail contains Gαi, an adenylate cyclase inhibitory subunit. This increases intracellular calcium level and inflammation via activation of ERK1/2, p38/MAPK, JNK, and PI3K/Akt. Activation of CXCR3B Gαs, adenylate cyclase stimulatory subunit, induces cell proliferation and migration.