BINDING OF HIV-2 ENVELOPE GLYCOPROTEIN TO CD8 MOLECULES AND RELATED CHEMOKINE PRODUCTION

We recently found that human immunodeficiency virus (HIV)-2 envelope g lycoprotein, but not that of HIV-1, could bind to CD4 and CD8 molecule s on T cells, and that the binding site of HIV-2 envelope glycoprotein was located on the alpha-chain (but not the beta-chain) of CD8. This study showed that the binding of HIV-2 envelope glycoprotein could ind uce phosphorylation of protein tyrosine kinase p56(lck) in CD8(+) T ce lls. We also found that production of beta-chemokines in response to H IV-2 envelope glycoprotein was significantly higher than that in respo nse to HIV-1 envelope glycoprotein, and that CD8(+) T cells were the m ain source of beta-chemokines production among the T-cell population. These findings indicate the possibility that the binding of envelope g lycoprotein to CD8 molecules are related to signal transduction into C D8(+) T cells and the resultant beta-chemokine production in HIV-2 inf ection. Our results may help to explain the differences in disease man ifestations between HIV-1 and HIV-2, including the lower virulence of HIV-2 and the longer survival of HIV-2-infected individuals.