title: Regulation of human B-cell activation, proliferation, and differentiation by soluble factors.
abstract: This review describes a series of studies performed in our laboratory which have focused on the activation and subsequent proliferation and differentiation of human B lymphocytes. Utilizing polyclonal signals which activate B cells by interacting with their surface membrane Ig, we have examined the events in the transition of a resting B lymphocyte to an Ig-secreting cell. A major theme in these studies is the role of soluble factors in B cell proliferation and B cell differentiation. Specific B cell growth and differentiation factors are described. Data on their sources, biochemical characterization, and methods of assay are included. Additionally, the potential role of interleukin 2 in human B cell function is discussed. The recognition that B cells exist in a variety of activation states and that transition between different states is dependent upon different signals was the impetus for a series of studies which more precisely delineated these states and the signals involved. These findings and the observations from other investigators led to a proposed model of the sequential steps in a factor-dependent B cell differentiation pathway. This model is discussed and related to the mechanisms of T cell activation and growth. Finally, the effects of two pharmacologic agents, glucocorticoids and cyclosporin A, on human B cell function are described and discussed in the context of this model.
mesh_terms: D000944:Antigens, Differentiation, B-Lymphocyte; D000954:Antigens, Surface / Q000494:pharmacology; D001402:B-Lymphocytes / Q000276:immunology*; D002453:Cell Cycle; D002454:Cell Differentiation; D006133:Growth Substances / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000276:immunology; D015847:Interleukin-4; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000494:pharmacology; D008954:Models, Biological; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000944:Antigens, Differentiation, B-Lymphocyte; D000954:Antigens, Surface; D006133:Growth Substances; D007376:Interleukin-2; D008222:Lymphokines; D015847:Interleukin-4