Characterization of the molecules on SJL/J lymphomas which stimulate syngeneic T cells.
I-A antigens isolated from SJL reticulum cell sarcoma (RCS) cells show greater heterogeneity with respect to charge and size of the A alpha chains than do I-A antigens isolated from normal SJL spleen cells. The relevance of these structural changes in RCS I-A to the previously shown syngeneic T cell stimulatory properties of RCS was investigated. It was shown that RCS cells expressed acidic forms of the A alpha chain on their cell surface which were not present on SJL spleen cells, peritoneal cells, or dendritic cells. The only normal cells which showed A alpha chain heterogeneity approaching that of RCS cells were LPS-induced B cell blasts. Treatment with tunicamycin completely abolished the RCS A alpha chain heterogeneity, whereas exposure to neuraminidase removed the charge heterogeneity, but not the size heterogeneity. Parallel studies of the syngeneic T cell proliferative response to RCS showed that tunicamycin abolished, while neuraminidase enhanced, the ability of RCS cells to stimulate syngeneic T cells. It is suggested that polysaccharide chains on RCS I-A molecules are particularly important for the biologic properties of these lymphoma cells. The possibility that highly glycosylated I-A antigens on normal B cell blasts are also involved in the stimulation of syngeneic T cells is discussed.
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D000951:Antigens, Neoplasm / Q000032:analysis / Q000302:isolation & purification; D000954:Antigens, Surface / Q000032:analysis / Q000302:isolation & purification; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006023:Glycoproteins / Q000378:metabolism; D000949:Histocompatibility Antigens Class II / Q000032:analysis* / Q000302:isolation & purification; D006863:Hydrogen-Ion Concentration; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation; D016403:Lymphoma, Large B-Cell, Diffuse / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D009439:Neuraminidase; D010529:Peritoneal Cavity / Q000166:cytology; D013601:T-Lymphocytes / Q000276:immunology*
D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D006023:Glycoproteins; D000949:Histocompatibility Antigens Class II; D008070:Lipopolysaccharides; D009439:Neuraminidase