Cross-linking of membrane IgM on B CLL cells.

We report here the study of early events following surface Ig cross-linking such as Ca2+ mobilization and IP3 generation, in chronic lymphocytic leukemia (CLL) B cells. Those leukemic populations were previously shown to be frozen at different stages of activation with unique requirements for proliferation. The study reported here disclosed 3 patterns of response in terms of Ca2+ mobilization and proliferation. These results are interpreted in terms of differential anti-mu signalling on B cells at different stages of activation.