Synergy between B cell differentiation factors and interleukin 2, using a monoclonal system.
By using monoclonal B cell targets, cells derived from patients with chronic lymphocytic leukemia, and B cell differentiation factors (BCDF) derived from monoclonal human T cell hybridomas, we have demonstrated marked synergy for differentiation between interleukin 2 (IL 2) and BCDF. IL 2 alone had no effect on the proliferation of differentiation to immunoglobulin secretion in these cell populations; however, in conjunction with a variety of BCDF, differentiation to plaque-forming cells (PFC) was augmented 10- to 100-fold. There was no increase in proliferation as measured by [3H]thymidine incorporation. These effects could be demonstrated with concentrations of IL 2 as low as 5 U/culture, well within the physiologic range, by using either commercially available or recombinant IL 2. The addition of IL 2 to the B cell and BCDF cultures resulted in almost 100% expression of the IL 2 receptor, Tac, on the surface of these cells, and the augmented PFC response could be inhibited 70 to 80% by the addition of anti-Tac to the culture. Kinetic studies revealed that the addition of IL 2 to the B cell cultures could be delayed for up to 72 hr without a change in the PFC response, suggesting that IL 2 was acting as a secondary or synergistic signal for differentiation. Thus, it appears that IL 2 does have a role in B cell maturation mediated, in part, by IL 2 binding to the IL 2 receptor present on certain B cells.
D000911:Antibodies, Monoclonal / Q000502:physiology; D000954:Antigens, Surface / Q000276:immunology; D001402:B-Lymphocytes / Q000166:cytology*; D001667:Binding, Competitive; D002454:Cell Differentiation; D002999:Clone Cells / Q000276:immunology / Q000378:metabolism; D004357:Drug Synergism; D006133:Growth Substances / Q000502:physiology*; D006801:Humans; D007376:Interleukin-2 / Q000502:physiology*; D015847:Interleukin-4; D007700:Kinetics; D007945:Leukemia, Lymphoid / Q000276:immunology; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000502:physiology*; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D006133:Growth Substances; D007376:Interleukin-2; D008222:Lymphokines; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D015847:Interleukin-4