Expression cloning of new receptors used by simian and human immunodeficiency viruses
Several members of the chemokine-receptor family serve, in conjunction with CD4, as receptors for the entry of human immunodeficiency virus type I (HIV-1) into cells. The principal receptor for entry of macrophage-tropic (M-tropic) HIV-1 strains is CCR5, whereas that for T-cell-line-tropic (T-tropic) strains is CXCR4. Unlike HIV-1, infection with either M- tropic or T-tropic strains of simian immunodeficiency virus (SIV) can be mediated by CCR5, but not CXCR4. SIV strains will also infect CD4⁺ cells that lack CCR5, which suggests that these strains use as yet unidentified receptors. Here the authors use an expression-cloning strategy to identify SIV receptors and have isolated genes encoding two members of the seven-transmembrane G-protein-coupled receptor family that are used not only by SIVs, but also by strains of HIV-2 and M-tropic HIV-1. Both receptors are closely related to the chemokine-receptor family and are expressed in lymphoid tissues. One of the receptors is also expressed in colon and may therefore be important in viral transmission. Usage of these new receptors following experimental infection of non-human primates with SIV strains may provide important insight into viral transmission and the mechanisms of SIV- and HIV- induced acquired immune-deficiency syndrome.
H Deng, D Unutmaz, V N KewalRamani & D R Littman
Expression cloning of new receptors used by simian and human immunodeficiency viruses (Letter to Nature)
Nature 388, 296 (1997) Nature © Macmillan Publishers Ltd. 1997
Registered No. 785998 England.