Studies on monoclonal anti-isotypic and anti-idiotypic antibodies against leukemia and myeloma: I. Study on monoclonal anti-idiotypic antibodies against lambda chain protein of myeloma

Studies on monoclonal anti-isotypic and anti-idiotypic antibodies against leukemia and myeloma: IV. Modulation of membrane fluidity of leukemic cell lines and tonsillar cell stimulated with McAbs

In this study the technique of labelling the cell membrane with DPH fluorescence polarization was used to observe the membrane fluidity of B lymphocytic cell lines and tonsillar cells from healthy persons; the modulation effect on membrane fluidity induced by McAbs against isotypic and idiotypic determinants of IgM from patients with leukemia was studied as well. The expression of the corresponding isotypic and idiotypic determinants of IgM on the cell membrane was determined. The results show that the membrane fluidity of leukemic cell lines is remarkably higher than that of tonsillar cells from healthy persons, and McAbs against isotypic determinants of leukemic IgM can enhance the membrane fluidity of all kinds of cells mentioned above. However, the anti-idiotypic monoclonal antibody increased only the membrane fluidity of leukemic cell lines. These results indicated that there was a close relationship between the effect of McAbs on cell membrane fluidity and the expression of corresponding isotypic and idiotypic determinants of IgM on the cell membrane.

Purification and immunoreactivity of monoclonal antibodies against myeloma-lambda chain

In this study, two murine IgM-monoclonal antibodies (IgM-McAbs) against lambda chain of myeloma protein from hybridoma ascites were purified by Sephadex G200 chromatography. The eluate of the first peak on absorption at 280 nm formed one precipitation band with rabbit anti-mouse IgM or anti-mouse immunoglobulin in agar gel double diffusion test; it also formed a detectable precipitation line in the IgM reaction area in immunoelectrophoresis. These findings showed that the eluate of the first peak on absorption at 280 nm contained purified IgM-McAbs. It was found in indirect ELISA that the immunoreactivity of the eluate of the first peak was four to five fold higher than that of the original ascites with equimolar protein concentration. Double antibody sandwich ELISA analyses of the immunoreactivity of HRP-conjugated IgM-monoclonal antibodies with lambda chain denoted that the purified IgM-McAb-HRP-conjugate might be of practical value in quantitative as well as qualitative assay of lambda chains.