Studies on monoclonal anti-isotypic and anti-idiotypic antibodies against leukemia and myeloma: II. Preparation and characteristics of monoclonal anti-isotypic antibodies to IgM from B chronic lymphocytic leukemia

Studies on monoclonal anti-isotypic and anti-idiotypic antibodies against leukemia and myeloma: VI. Purification and relative affinity of monoclonal antibodies

In this study, the anti-idiotypic and anti-isotypic antibodies (McAbs) against IgM of the Patient with B chronic lymphocytic leukemia (B-CLL) were purified from hybridoma ascites by n-Octoic acid precipitation method. The purified McAbs have high purify and high antibody activity as evidenced by immunoelectrophoresis, SDS-PAGE and ELISA. Relative affinity of 11 McAbs was measured by using indirect ELISA and double antibody sandwich ELISA method. It was found that relative affinity of various McAbs to the same antigen was different. 11 McAbs could be divided into two groups by analysing their 50% maximum binding. The relative affinity of 4 McAbs in the culture supernatants was consistent with that of McAbs in the purified ascites. Our experimental results provide an important basis for rational application of these McAbs.

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.

Studies on monoclonal anti-idiotypic and anti-isotypic antibodies against leukemia and myeloma: III. Analysis of monoclonal antibodies recognizing the antigenic epitopes by use of ELISA additivity test and microcomputer grouping programme

ELISA double antibodies additivity test was employed to identify the epitopes which can be recognized by monoclonal antibodies (McAbs) against IgM of a patient with B chronic lymphocytic leukemia (B-CLL). The computer grouping programme analysis showed that 4 anti-isotype McAbs could be divided into two groups and 10 anti-idiotype McAbs could be divided into four groups. The result was consistent with that of the indirect ELISA, ELISA sandwich as well as ELISA inhibition test. The above findings suggested that there are at least 6 distinct IgM epitopes which can specifically react with 14 McAbs. Our study indicated that the combination of the ELISA additivity test and the computer grouping programme analysis provides a helpful tool for researchers into the relationship between the structure and function of antigens.