title: Human T cell hybridomas secreting factors for IgA-specific help, polyclonal B cell activation, and B cell proliferation.
abstract: Human T-T hybridomas were established by fusion of concanavalin A-activated OKT-4+ T cells with hypoxanthine guanine phosphoribosyl transferase-deficient as well as nondeficient T cell lines. Four hybrids were selected for further study. Supernatant from hybrid clone J1.3 specifically enhanced IgA production and secretion by isolated human B cells, with increases in IgA plaque-forming cells approaching those seen with addition of autologous T cells and pokeweed mitogen. A monoclonal lymphocytic leukemia with membrane IgA also differentiated to IgA plasma cells by this supernatant. Evidence suggests that this hybrid supernatant acts on post-switch IgA-committed B cells. The other hybrids were not isotype specific; hybrid J2S1 enhanced polyclonal Ig secretion and hybrids K1 and K8 induced B cell proliferation without induction of Ig secretion.
mesh_terms: D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D006133:Growth Substances / Q000096:biosynthesis* / Q000494:pharmacology; D006801:Humans; D006825:Hybridomas / Q000276:immunology*; D007070:Immunoglobulin A; D015847:Interleukin-4; D007945:Leukemia, Lymphoid / Q000276:immunology; D008213:Lymphocyte Activation; D010641:Phenotype; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D006133:Growth Substances; D007070:Immunoglobulin A; D015847:Interleukin-4