HUMAN ERYTHROCYTE GLYCOLIPIDS PROMOTE HIV-1 ENVELOPE GLYCOPROTEIN-MEDIATED FUSION OF CD4(+) CELLS

We examined the role of target membrane glycolipids in CD4-mediated HI V-1 fusion by altering the glycolipid levels in CD4(+) cells. CD4(+) h uman cells exhibited 50% reduction in extent of fusion with gp120-gp41 expressing cells (TF228) when grown in the presence of a glycolipid s ynthesis inhibitor PPMP. We added erythrocyte glycolipids (GL) to fusi on-incompetent CD4(+) non-human cells by influenza-hemagglutinin-media ted fusion between GL-containing liposomes and target cells. Human ery throcyte GL (HuGL)-modified CD4(+) non-human cells became susceptible to fusion with TF228 cells. Transfer of bovine erythrocyte glycolipids (BoGL) to CD4(+) non-human cells under similar conditions did not com plement HIV-1 fusion, Furthermore, addition of HuGL, but not BoGL, to PPMP-inhibited cells rescued fusion to the original levels. Our observ ations demonstrate that human erythrocyte glycolipids promote CD4-medi ated HIV-1 fusion and certain glycolipid(s) from human erythrocytes ma y serve as alternative and/or additional cofactors in HIV-1 entry. (C) 1998 Academic Press.