HUMAN PLASMATIC APOLIPOPROTEIN-H BINDS HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 AND TYPE-2 PROTEINS

Apolipoprotein H (ape H), isolated from human plasma albumin solution, was shown to capture HIV-l-related antigens from antigen-positive ser a (HIV-1 AG(+)) of AIDS patients, by using HIV-1-specific polyclonal a ntibodies, In an enzyme-linked immunosorbent assay and ligand blot and dot assays, apo H was able to bind recombinant retroviral HIV antigen s, especially Gag proteins p18 of HIV-1, p26 of HIV-2, and Env gp160 o f HIV-1, Binding was shown to be pH and NaCl dependent, with an optimu m at acidic pH and low ionic strength, Specificity was demonstrated by saturation of this binding and inhibition either by homologous compet ition or by specific antisera, Binding was also observed in cell line- harvested viral blotted proteins, The mechanism of this apo H-polyspec ific binding is discussed in relation to conformational changes due to the influence of lipids or detergents.