Mast cells and basophils (Fc epsilon RI+ cells) are classically involved in
allergic disorders. HIV-1 glycoprotein gp120 acts as a viral superantigen
by interacting with the heavy chain, variable 3 (V(H)3) region of IgE to in
duce cytokine release from Fc epsilon RI+ cells. The chemokine receptors CC
R3 and CXCR4, co-receptors for HIV-1, a re expressed by Fc epsilon RI+ cell
s, Via its interaction with CCR3, HIV-1 transactivation (Tat) protein is a
potent chemoattractant for Fc epsilon RI+ cells. Incubation of basophils wi
th Tat protein upregulates the surface expression of the CCR3 receptor. The
re is some evidence that human Fc epsilon RI+ cells could be infected in vi
tro by M-tropic HIV-1 strains.