title: Human CD8+ lymphocytes stimulated in the absence of CD4+ cells enhance IgG production by antibody-secreting B cells.
abstract: We describe conditions where the addition of stimulated CD8+ lymphocytes from healthy donors to autologous antibody-secreting B cells significantly enhanced IgG production by these cells. In two-step experiments, purified CD8+ lymphocytes were first cocultured with irradiated allogeneic monocytes. These cells developed interleukin 2 receptors, but proliferated only minimally in the absence of CD4+ cells. When added to antibody-secreting B cells, these CD8+ lymphocytes augmented IgG production in a dose-dependent manner in comparison with control CD8+ cells. Studies with T killer cell precursors revealed an inverse correlation between augmentation of antibody synthesis and the generation of MHC class I-restricted cytotoxic activity against lymphocytes from the allogeneic donor. Evidence is presented that CD8+ CD45RA+ CD45RO- can provide B cell help, whereas the generation of CD8+ CD45RA+ CD45RO+ cells inhibits this helper activity. Our studies support the hypothesis that in chronic diseases characterized by CD4+ cell hypofunction, CD8+ cells not only fail to down-regulate antibody production, but can provide B cell help.
authors.affiliation: Department of Medicine, University of Southern California School of Medicine, Los Angeles 90033.
authors.forename: T
authors.initials: T
authors.lastname: Takahashi
authors.forename: J D
authors.initials: JD
authors.lastname: Gray
authors.forename: D A
authors.initials: DA
authors.lastname: Horwitz
mesh_terms: D000943:Antigens, Differentiation / Q000502:physiology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000502:physiology*; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D015704:CD4 Antigens / Q000502:physiology*; D016827:CD8 Antigens; D003602:Cytotoxicity, Immunologic / Q000276:immunology; D005434:Flow Cytometry; D006649:Histocompatibility Antigens / Q000502:physiology; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis*; D016130:Immunophenotyping; D066298:In Vitro Techniques; D017493:Leukocyte Common Antigens; D008213:Lymphocyte Activation; D016131:Lymphocyte Subsets / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000943:Antigens, Differentiation; D000945:Antigens, Differentiation, T-Lymphocyte; D015704:CD4 Antigens; D016827:CD8 Antigens; D006649:Histocompatibility Antigens; D007074:Immunoglobulin G; D017493:Leukocyte Common Antigens