ARTIFICIAL VIRAL ENVELOPES CONTAINING RECOMBINANT HUMAN-IMMUNODEFICIENCY-VIRUS (HIV) GP160

An artificial viral envelope was constructed, resembling the human immunodeficiency virus (HIV) envelope with respect to ultrastructure, size, phospholipid profile and lipid:cholesterol ratio. Recombinant HIV surface protein gp160 was anchored in the outer surface of the envelope membrane using a double detergent dialysis. The envelopes remained physically stable for several months. Immunolabeling with anti-gp160/41 monoclonal antibody revealed surface insertion and availability of gp160 for binding. Cell fusion and cytosolic transfer of the encapsulated fluorescent marker FITC-dextran was demonstrated. Flow cytometry indicated more efficient transfer of the fluorescent marker to cells which were almost-equal-to 60% CD4+ (REX-1B), relative to cells which were only almost-equal-to 18% CD4+ (KG-1). However, plain lipid envelopes without gp160 fused very efficiently with both cell types, indicating their potential usefulness as "fusogenic liposomes". Complete artificial viral envelopes may serve as subunit vaccines, and receptor-targeted delivery systems for drugs, toxins and genetic constructs.