@article{mbs:/content/journal/jgv/10.1099/0022-1317-79-7-1793, author = "Reeves, Jacqueline D and Heveker, Nikolaus and Brelot, Anne and Alizon, Marc and Clapham, Paul R and Picard, Laurent", title = "The second extracellular loop of CXCR4 is involved in CD4-independent entry of human immunodeficiency virus type 2.", journal= "Journal of General Virology", year = "1998", volume = "79", number = "7", pages = "1793-1799", doi = "https://doi.org/10.1099/0022-1317-79-7-1793", url = "https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-79-7-1793", publisher = "Microbiology Society", issn = "1465-2099", type = "Journal Article", abstract = "Human immunodeficiency virus type 2 (HIV-2) strains that infect cells in the absence of cellular CD4 emerge spontaneously in vitro after culture in CD4 T-cell lines. The HIV-2ROD/B strain can use the CXCR4 chemokine receptor for efficient entry into CD4 cells. Here we have shown that the rat homologue of CXCR4, in the absence of CD4, failed to mediate CD4-independent entry by ROD/B. Furthermore, using rat-human chimeric CXCR4 receptors we have demonstrated that the second extracellular loop (E2) of human CXCR4 is critical for HIV-2 infection of CD4 cells. E2 is also important for HIV-1 infection of CD4 cells. Our results therefore indicate that the role of E2 in HIV entry is conserved for HIV-1 and HIV-2 and for infection in the presence or absence of CD4.", }