B cell maturation in chronic lymphocytic leukemia. II. Clonal heterogeneity in the response to various B cell activators and recombinant cytokines (rIFN-gamma, rIFN-alpha, rIL2).
Maturation of B cells into immunoglobulin (Ig)-secreting cells is influenced by antigen-nonspecific growth and differentiation factors. In the present study, we have analyzed the effect of several recombinant cytokines (rIL2, rIFN-alpha, rIFN-gamma) on the terminal differentiation of B cells from 10 patients with chronic lymphocytic leukemia (CLL) stimulated with three different B cell activators (phorbolester TPA, staphylococcus aureus Cowan I bacteria, or pokeweed mitogen). Secretion of IgM, as determined by heavy-chain specific ELISA, varied widely among different CLL cell populations, but was induced in all cases by one or several of these activators. Importantly, this response was enhanced 2-10-fold in all patients by at least one of the tested recombinant cytokines alone, or a combination of rIL2 with rIFN-alpha or rIFN-gamma. The results illustrate the clonal heterogeneity of CLL B cell maturation in vitro and demonstrate that rIL2, rIFN-alpha or rIFN-gamma can act as a B cell differentiation factor, depending on the responsiveness (stage of differentiation) of the individual clonal B cell population.
D001402:B-Lymphocytes / Q000276:immunology / Q000473:pathology*; D001688:Biological Products / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D002999:Clone Cells / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D016207:Cytokines; D006801:Humans; D007075:Immunoglobulin M / Q000096:biosynthesis; D007370:Interferon Type I / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology; D007376:Interleukin-2 / Q000494:pharmacology; D007945:Leukemia, Lymphoid / Q000276:immunology / Q000473:pathology*; D008934:Mitogens / Q000494:pharmacology
D001688:Biological Products; D016207:Cytokines; D007075:Immunoglobulin M; D007370:Interferon Type I; D007376:Interleukin-2; D008934:Mitogens; D007371:Interferon-gamma