title: Properties of an anti-idiotype antiserum: demonstration of cross-reacting mitogenic determinants on bone marrow plasmacytoma cells.
abstract: An antiserum against a monoclonal protein of IgG/kappa type from a patient S. was produced by immunization of guinea pigs. Idiospecificity of the antiserum (anti-Id AS) was tested by immunoprecipitation and hemagglutination inhibition. About 70% mononuclear cells prepared from the bone marrow (BM) aspirate of this patient stained positive when the antiserum was used in an indirect immunofluorescence (IF) procedure detecting surface membrane structures. Commercial antisera specific for gamma, kappa and lambda immunoglobulin (Ig) chains stained only 5-17% of the cells. With mu chain and delta chain specific antisera no reactivity could be observed. The presence of idiotype cross-reacting determinants (Id-CR-D), that is idiotypes not associated with Ig isotypes could be also demonstrated by a significant increase of 3H-thymidine incorporation of the BM cells in the presence of the anti-Id AS. Phytohemagglutinin (PHA), pokeweed mitogen (PWM) and concanavalin A had no effect. In a cell sorting experiment using affinity gel chromatography it could be shown that the anti-Id AS preferentially binds to proplasmacytes. Cells of this type were enriched two-fold over plasma cells in the eluate. The analysis of peripheral blood lymphocytes (PBL) from the patient revealed about 40% positive cells without correlation to a certain subpopulation. Administration of prednisolone to the patient resulted in a significant reduction of the Id positive cells within two days. In conclusion it appears that our antiserum detects cells of an individual tumour clone within PBL and BM-cells. By the stimulating effect of the anti-Id AS a proliferative potential of plasmacytoma cells could be defined which may work also 'in vivo'. Thus, Id-CR-D may operate as a tumour growth receptor.
mesh_terms: D000954:Antigens, Surface / Q000032:analysis; D001853:Bone Marrow / Q000276:immunology; D002462:Cell Membrane / Q000276:immunology; D003429:Cross Reactions; D000939:Epitopes / Q000032:analysis; D005260:Female; D006801:Humans; D007106:Immune Sera; D005779:Immunodiffusion; D007130:Immunoglobulin Idiotypes / Q000276:immunology*; D008214:Lymphocytes / Q000276:immunology; D008875:Middle Aged; D010954:Plasmacytoma / Q000188:drug therapy / Q000276:immunology*; D011239:Prednisolone / Q000627:therapeutic use
chemical_list: D000954:Antigens, Surface; D000939:Epitopes; D007106:Immune Sera; D007130:Immunoglobulin Idiotypes; D011239:Prednisolone