title: Differences in the expression of histocompatibility antigens on mouse lymphocytes and tumor cells: immunochemical studies.
abstract: Immunochemical studies have shown that labeled, detergent-solubilized extracts of SL2 (H-2d) lymphoma cells contain components reactive with several anti-H-2 alloantisera of restricted specificity. Anti-H-2k and anti-H-2ja as well as anti-H-2d sera precipitated labeled polypeptides of a molecular weight similar to that of H-2 heavy chains. In addition, all antisera tested precipitated a component of 70000 daltons molecular weight, which is antigenically related to gp 69/71 of Friend murine leukemia virus. Reactions with antisera directed against haplotypes other than H-2d could be blocked by addition of unlabeled, detergent-solubilized extracts of H-2d lymphocytes, or by H-2 antigens against which the antiserum was directed. Sequential immunoprecipitations initially using antisera against the K, D, or L region gene products to remove individual known H-2d antigens have made possible the identification of some molecules responsible for these reactions. The results show that antisera against haplotypes other than H-2d which react with SL2 cells, cross-react with normal H-2d antigens. Quantitative absortion of these antisera with intact or solubilized cells has shown that lymphocytes and tumor cells differ in their expression of some H-2 determinants. The antibodies bind only weakly to intact H-2d lymphocytes, but strongly to the corresponding detergent-solubilized antigens. These results do not, therefore, support the derepression hypothesis put forward earlier.
mesh_terms: D000818:Animals; D000941:Antigens; D001667:Binding, Competitive; D002462:Cell Membrane / Q000276:immunology; D011232:Chemical Precipitation; D000939:Epitopes; D006183:H-2 Antigens / Q000276:immunology*; D007106:Immune Sera / Q000494:pharmacology; D009052:Leukemia Virus, Murine / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology*; D008223:Lymphoma / Q000276:immunology*; D051379:Mice; D008811:Mice, Inbred DBA; D013154:Spleen / Q000276:immunology
chemical_list: D000941:Antigens; D000939:Epitopes; D006183:H-2 Antigens; D007106:Immune Sera