
<ArticleTitle>Are mast cells MASTers in HIV-1 infection?</ArticleTitle>
<AbstractText>HIV-1 <prot>gp120</prot> interacts with <prot>IgE V(H)3</prot>(+) on the surface of human basophils and mast cells (Fc epsilon RI(+) cells), acting as a viral immunoglobulin superantigen. <prot>gp120</prot> from different clades induces mediator release from Fc epsilon RI(+) cells. <prot>gp120</prot> also induces <prot>IL-4</prot> and <prot>IL-13</prot> synthesis in human basophils. The chemokine receptors <prot>CCR3</prot> and <prot>CXCR4</prot>, which are coreceptors of HIV-1 infection, are expressed by human Fc epsilon RI(+) cells. HIV-1 <prot>Tat</prot> protein is a potent chemoattractant for basophils and lung mast cells, interacting with <prot>CCR3</prot>. Incubation of basophils with <prot>Tat</prot> protein upregulates the surface expression of the <prot>CCR3</prot> receptor. There is evidence that human Fc epsilon RI(+) cells could be infected in vitro by M-tropic HIV-1 strains.</AbstractText>
