Lipid vesicle-cell interactions. III. Introduction of a new antigenic determinant into erythrocyte membranes.
The introduction of a new antigenic determinant, 2,4-dinitrophenyl-aminocaproyl-phosphatidylethanolamine (DNP-Cap-PE), into the surface membranes of intact human erythrocytes is described. Fresh cells were incubated in the presence of liposomes composed of 10% DNP-Cap-PE, 5% stearylamine, 20% lysolecithin, and 65% lecithin. Such liposome-treated erythrocytes are shown to be susceptible to immune lysis by anti-DNP serum in the presence of complement. Uptake of DNP-Cap-PE by erythrocyte membranes is also demonstrated by immunofluorescence using indirect staining with rabbit anti-DNP serum followed by fluroescein-conjugated goat anti-rabbit IgG and by electron microscopy using ferritin-conjugated antibody. Antigen uptake did not occur at low temperatures or from vesicles lacking lysolecithin and stearylamine. Fluorescence microscopy shows that the antigen-antibody complexes are free to diffuse over the cell surface, eventually coalescing into a single area on the cell membrane. Electron microscopy suggests that a substantial proportion of the lipid antigen is incorporated by fusion of vesicles with the cell membrane. There are indications that vesicle treatment causes a small proportion of cells to invaginate.
D000371:Agglutination; D000936:Antigen-Antibody Complex; D000937:Antigen-Antibody Reactions; D000941:Antigens; D002462:Cell Membrane / Q000276:immunology*; D003165:Complement System Proteins; D000939:Epitopes; D004912:Erythrocytes / Q000276:immunology* / Q000648:ultrastructure; D005455:Fluorescent Antibody Technique; D006461:Hemolysis; D008081:Liposomes / Q000276:immunology / Q000502:physiology*; D014617:Vacuoles / Q000648:ultrastructure
D000936:Antigen-Antibody Complex; D000941:Antigens; D000939:Epitopes; D008081:Liposomes; D003165:Complement System Proteins