A MONOCLONAL-ANTIBODY DIRECTED TO SULFATIDE INHIBITS THE BINDING OF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 (HIV-1) ENVELOPE GLYCOPROTEIN TO MACROPHAGES BUT NOT THEIR INFECTION BY THE VIRUS

We show here that human immunodeficiency virus (HIV) envelope glycopro teins (gp160/gp120) bind to sulfatide and galactosyl ceramide. By immu nofluorescence labeling with monoclonal antibody (mAb) A2B5, specific for ganglioside/sulfatide, we detect negatively charged glycolipids on CD4(+) cells of the macrophage lineage and lymphocytes. Labeling of m onocyte-derived macrophages (MDM) with mAb A2B5 was reproducibly found in 29 healthy donors, independently of the culture method and duratio n up to 11 days. The binding of the mAb to neuraminidase-treated MDM w as unchanged relative to control cells, but mAb binding decreased afte r arylsulfatase treatment, which indicates that MDM membrane sulfatide is its major ligand. Preincubating MDM with the mAb partially (40-60% ) but significantly inhibited the binding of HIV-1(LAI) radiolabeled r ecombinant gp160 to the cells. Similarly, the mAb entailed limited (32 %) but significant inhibition of gp160 binding to cells of the monocyt ic U937 line but not to lymphoid CEM cells. However, mAb A2B5 did not inhibit the infection of CEM nor of U937 cells by HIV-1(LAI) strain, n or of MDM by monocytotropic HIV-1(BaL). Thus, although sulfatide may b e involved in the binding of HIV env glycoprotein to MDM or monocytic U937 cells, this does not play a significant role in HIV infection of these CD4(+) cells.