title: Regulation of myeloma growth in vitro by idiotype-specific T lymphocytes.
abstract: Spleen cells of BALB/c mice immunized with purified BALB/c myeloma protein (MP) caused idiotype-specific suppression of DNA synthesis and colony formation by myeloma cells in vitro. Lymphocytes from mice immunized with 315-MP inhibited only MOPC-315 plasmacytoma cells; conversely, lymphocytes from mice immunized with 167-MP inhibited only MOPC-167 plasmacytoma cells. Antisera from those mice that showed cell-mediated inhibition of myeloma growth had no significant effect. The suppressive activity of the spleen cells was markedly reduced by treatment with anti-Thy 1.2 and complement, and the immune cells responsible for the suppression did not adhere to nylon wool. The suppressor cells adsorbed to myeloma protein-coated plates, and after elution, inhibited myeloma cells specifically at a 1:1 effector to target cell ratio. Suppression of myeloma growth was due to cytostatic rather than cytolytic effects. These findings suggest that mice immunized with purified myeloma protein have idiotype-specific T cells that can regulate myeloma cell growth. This mechanism may provide an explanation for the transplantation resistance to myelomas induced by immunization with myeloma protein. Similar idiotype-specific T cells may also play a role in the idiotype-specific regulation of immune responses by acting late in differentiation to block the proliferation of antibody-secreting normal B cells.
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D000961:Antilymphocyte Serum / Q000494:pharmacology; D002448:Cell Adhesion; D002471:Cell Transformation, Neoplastic; D002999:Clone Cells / Q000276:immunology; D003165:Complement System Proteins; D005260:Female; D007130:Immunoglobulin Idiotypes; D051379:Mice; D008807:Mice, Inbred BALB C; D009194:Myeloma Proteins / Q000276:immunology*; D010954:Plasmacytoma / Q000276:immunology*; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D013936:Thymidine / Q000378:metabolism
chemical_list: D000961:Antilymphocyte Serum; D007130:Immunoglobulin Idiotypes; D009194:Myeloma Proteins; D003165:Complement System Proteins; D013936:Thymidine