A monoclonal antibody directed to sulfatide inhibits the biding of human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein to macrophages but not their infections by the virus

Abstract

We show here that human immunodeficiency virus HIV) envelope glycoproteins (gp160/ gp120) bind to sulfatide and galactosyl ceramide. By immunofluorescence labeling with monoclonal antibody (mAb) A2B5, specific for ganglioside/sulfatide, we detect negatively charged glycolipids on CD4 + cells of the macrophages lineage and lymphocytes. Labeling of monocyte-derived macrophages (MDM) with mAb A2B5 was reproducibly found in 29 healthy donors, independently of the culture method and duration up to 11 days. The binding of the mAb to neuraminidase-treated MDM was uncharged relative to control cells, but mAb binding decreased after 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 recombinant gp160 to the cell. Similarly, the mAb entailed limited (32%) but significant inhibition of gp160 binding to cells of the monocytic U937 line but no to lymphoid CEM cells. However, mAb A2B5 did not inhibit the infection of CEM nor of U937 cells by HIV-1 lai strain, nor of MDM by monocytotrophic HIV-1 bal . Thus, although may be 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.