title: The role of idiotype-specific, CD4+ T cells in tumor resistance against major histocompatibility complex class II molecule negative plasmacytoma cells.
abstract: It is known that immunoglobulins can be processed and that idiotypic peptides are presented on MHC class II molecules to T cells. It has also been demonstrated that T cells can recognize a complex of an Id-peptide/MHC molecule as a tumor-specific antigen on B lymphoma cells. However, plasmacytomas, an important type of B cell malignancies, most often lack class II molecules and are thus expected to be poor targets for Id-specific, CD4+ T cells. Nevertheless, we now demonstrate that cloned, MHC class II restricted T cells, specific for a lambda 2(315) idiotypic peptide, convey protection in vivo (Winn assay) against the class II molecule-negative MOPC315 (alpha, lambda 2(315)) plasmacytoma. T cells can also inhibit the growth of MOPC315 cells in vitro provided that MHC compatible (H-2d) splenocytes and extra lambda 2(315) are added. Based on these data we suggest that the myeloma protein secreted by MOPC315 cells attains such a high local concentration in vivo that it is processed and presented by neighboring host APC to the Id-specific T cells. Such activated T cells secrete lymphokines which may directly affect the growth of MOPC315 cells in the vicinity. Alternatively, lymphokines from activated T cells stimulate local host cells, like macrophages, to become tumoricidal.
authors.affiliation: Institute of Immunology and Rheumatology, University of Oslo, Norway.
authors.forename: G F
authors.initials: GF
authors.lastname: Lauritzsen
authors.forename: B
authors.initials: B
authors.lastname: Bogen
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D007130:Immunoglobulin Idiotypes / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology; D016393:Lymphoma, B-Cell / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010954:Plasmacytoma / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014407:Tumor Cells, Cultured
chemical_list: D000949:Histocompatibility Antigens Class II; D007130:Immunoglobulin Idiotypes