title: Suppressor activity of splenic macrophages in murine plasmacytoma (PC) is inhibited by PC specific ligands.
abstract: Spleens of BALB/c mice with plasmacytoma contain macrophages (M phi) which were found to suppress the in vitro immune function of normal splenic cells through a diffusible factor. The suppressor activity of these macrophages was reversibly inhibited by ligands specific for the corresponding PC globulin, but not by anti-idiotypic antibody. Anti-idiotypic antibody with complement, however, abrogated the suppressor function, presumably by cytotoxicity. Anti-isotype with complement was ineffective. These findings suggest binding of ligand to a surface receptor of the suppressor M phi that although clearly not PC globulin, may be structurally similar to the PC idiotype. These receptors are retained in 3 day cultures of macrophages and are not removed by intensive washing. Ligand binding appears to modulate the suppressor function of M phi through blocking of the production of diffusible suppressor factor.
mesh_terms: D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D000917:Antibody Formation / Q000187:drug effects; D002470:Cell Survival; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D003911:Dextrans / Q000494:pharmacology; D004140:Dinitrophenols / Q000494:pharmacology; D007130:Immunoglobulin Idiotypes / Q000276:immunology; D008222:Lymphokines / Q000378:metabolism; D008264:Macrophages / Q000187:drug effects / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009374:Neoplasms, Experimental / Q000276:immunology; D010954:Plasmacytoma / Q000276:immunology*; D011971:Receptors, Immunologic / Q000187:drug effects; D013154:Spleen / Q000276:immunology; D013491:Suppressor Factors, Immunologic; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D000888:Antibodies, Anti-Idiotypic; D003911:Dextrans; D004140:Dinitrophenols; D007130:Immunoglobulin Idiotypes; D008222:Lymphokines; D011971:Receptors, Immunologic; D013491:Suppressor Factors, Immunologic; C013256:soluble immune response suppressor