Cloned murine Ia+ BK-BI-2.6.C6 T cells function as accessory cells presenting protein antigens to long-term-cultured antigen-specific T cell lines.
A variant clone, BK-BI-2.6.C6, was derived from the murine bovine insulin-reactive T cell line BK-BI-2.6 with helper/amplifier phenotype. Variant cells have lost reactivity to insulin, but have acquired constitutive IL 2 receptor expression, growing in IL 2-containing medium without feeder cells. In contrast to their ancestor line, variant cells synthesize and express I-A and I-E region-dependent class II molecules as indicated by metabolic radiolabeling, immunoprecipitation with subregion-specific monoclonal antibodies and two-dimensional (2D) gel electrophoresis (1D isoelectric focusing, 2D SDS-PAGE). BK-BI-2.6.C6 cells can act as accessory cells, presenting the protein antigens bovine insulin and ovalbumin to antigen-dependent long-term cultured T cell lines BK-BI-1.2 and BK-OVA-1 in the context of I-A restriction elements. Antigen recognition on presenting BK-BI-2.6.C6 accessory cells resulted in highly efficient IL 2 production. However, in contrast to splenic antigen-presenting cells, BK-BI-2.6.C6 cells did not initiate antigen-specific [3H]thymidine incorporation by the T cell lines tested. Further study of accessory function of Ia+ T cell clones might provide insight into processes regulating T cell responses to antigen.
D000818:Animals; D000938:Antigen-Presenting Cells / Q000166:cytology / Q000276:immunology*; D000954:Antigens, Surface / Q000032:analysis; D002453:Cell Cycle; D002460:Cell Line; D002999:Clone Cells; D004306:Dose-Response Relationship, Immunologic; D005434:Flow Cytometry; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D007328:Insulin / Q000276:immunology; D007376:Interleukin-2 / Q000096:biosynthesis; D007526:Isoelectric Point; D008213:Lymphocyte Activation; D008285:Major Histocompatibility Complex; D051379:Mice; D008970:Molecular Weight; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*
D000954:Antigens, Surface; D000949:Histocompatibility Antigens Class II; D007328:Insulin; D007376:Interleukin-2