Studies on monoclonal anti-idiotypic antibodies to human B cell leukemia

Murine immunocytoma cell line, NS-1, was fused with spleen cells of Balb/C mice which had been stimulated by tolerogenic disaggregated human gamma globulin and immunized by purified serum IgM from the patient with chronic B cell leukemia (B-CLL). 10 hybridoma cell lines secreting monoclonal anti-idiotype (anti-Id) antibodies to human CLL were obtained. The McAbs were subclasses belonging to IgM and of IgG mouse. Specificity and biologic characters of the monoclonal anti-Id antibodies from culture fluid or ascites were assayed by ELISA, indirect mixed ELISA sandwich, ELISA inhibition, immunofluorescence (IF) and IF inhibition. The study also proved that monoclonal anti-Id antibodies could react with homologous IgM, but not with Ig from normal donors or a panel of patients with myeloma. The results of IF and IF inhibition assay showed that monoclonal anti-Id antibodies were bound to lymphocytes of patient with B-CLL. Their reactivity was inhibited by homologous IgM, but not by lymphocytes of patients with ALL or lymphoma. Monoclonal anti-Id antibodies were heterogenous reactive patterns with cell lines in vitro.