Exclusion of HIV coreceptors CXCR4, CCR5, and CCR3 from the HIV envelope.

Both HIV-1 primary isolates and laboratory strains incorporate cell-derived molecules into their envelopes depending on the host cell in which they are grown. This incorporation is not random and, specifically, HIV-1 has been shown to select against the incorporation into its surface of CD4, its main receptor. In this study, we have looked at the incorporation of HIV coreceptors CXCR4, CCR5, and CCR3 into the HIV envelope. For this purpose, we grew HIV-1 primary isolate BZ167 in several cell lines and PBMCs, and the envelope profiles of the resulting viruses were determined with a virus-binding ELISA. While the virus particle gained several molecules when passed through the different cell lines (e.g., ICAM-3, LFA-1, ICAM-1, or MHC class II), BZ167 never incorporated significant levels of CXCR4, CCR5, or CCR3 into its envelope even though some or all of the cell lines in which it was grown expressed them. These results show that HIV-1 selects against the incorporation of these chemokine receptors into its envelope molecule, as it does against the incorporation of CD4.