title: Detection of cross-reacting murine I-J like determinants on a human subset of T8+ antigen binding, presenting and contrasuppressor cells.
abstract: Murine I-J gene products have been found in T suppressor cells (SC) and factors, macrophages and contrasuppressor cells (CSC). However, a human counterpart of the murine I-J has not been reported. As there is strong evidence that some murine anti-Ia antisera cross-react with human Ia antigens, the possibility was tested that mouse anti-I-J antibodies might cross-react with corresponding human class II determinants. Indeed, this revealed that three anti-I-J monoclonal antibodies (MoAb) and two antisera tested react with human mononuclear cells and that a significantly greater proportion of T8+ than T4+ cells or monocytes (Mo) react with the I-J antibodies. This was corroborated by autoradiography with significant inhibition of 125I-SA (streptococcal antigen) binding to T8+ cells but not to Mo by the MoAb or antisera to murine I-J. Functional reconstitution experiments of T4+ helper cells with the SA binding and presenting T8+ Vicia villosa adherent cells (VV-AC) and assessment of specific antibody forming cells to SA suggest that the antigen presenting function of this T8+ subset can be significantly inhibited by killing with the MoAb to I-J and complement. Furthermore, the subset of T8+ VV-AC also functions as CSC, for killing with MoAb to I-J and complement significantly inhibited the contrasuppressor function. This is consistent with the presence of I-J gene products in murine CSC. However, similar treatment of T8+ VV-NAC (non-adherent cells) or monocytes (Mo) failed to affect the suppressor or accessory helper function of these cells, respectively. Phenotypic characterization, inhibition of 125I-SA binding and reconstitution experiments for helper and suppressor functions, suggest that a subset of T8+ antigen binding, presenting and CSC may express determinants cross-reacting with murine I-J molecules.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D003429:Cross Reactions; D000939:Epitopes / Q000032:analysis*; D006183:H-2 Antigens / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006801:Humans; D007376:Interleukin-2 / Q000276:immunology; D008222:Lymphokines / Q000276:immunology; D051379:Mice; D009000:Monocytes / Q000276:immunology; D010641:Phenotype; D014176:Protein Biosynthesis; D013491:Suppressor Factors, Immunologic; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D006183:H-2 Antigens; D000949:Histocompatibility Antigens Class II; D007376:Interleukin-2; D008222:Lymphokines; D013491:Suppressor Factors, Immunologic