title: Biologic and chemical characterization of HLA antigens in human serum.
abstract: HLA antigens of both the A and B loci were shown to be associated with the high density lipoprotein fraction of serum prepared by ultracentrifugal flotation. HLA-A9 antigens were purified 100-fold with essentially complete recovery by a simple procedure of high density lipoprotein preparation involving precipitation with polyanions and ultracentrifugal flotation. The purified lipid-associated antigen was immunogenic since it elicited the formation of cytotoxic xenoantibodies in rabbits. Serum HLA-A9 antigens were found by immunoprecipitation and gel electrophoresis to consist of a 45,000 m.w. heavy chain associated with beta2-microglobulin. The size of the HLA-lipid complex (less than 190,000 m.w.) and of the HLA-deoxycholate complex (less than 102,000 m.w.) suggests that HLA antigens are shed into plasma as a complex of a single HLA molecule and a single beta2-microglobulin chain, associated with boundary lipid.
mesh_terms: D000906:Antibodies; D001769:Blood / Q000276:immunology*; D002850:Chromatography, Gel; D003601:Cytotoxicity Tests, Immunologic; D004591:Electrophoresis, Polyacrylamide Gel; D005590:Fractional Precipitation; D006680:HLA Antigens / Q000302:isolation & purification; D006649:Histocompatibility Antigens / Q000302:isolation & purification; D006801:Humans; D007163:Immunosorbent Techniques; D008075:Lipoproteins, HDL / Q000302:isolation & purification; D014461:Ultracentrifugation
chemical_list: D000906:Antibodies; D006680:HLA Antigens; D006649:Histocompatibility Antigens; D008075:Lipoproteins, HDL