Characterization of T-cell-soluble factors modulating the expression of Ia and H-2 antigens on BALB/c B lymphoma cell lines.
The effect of supernatants of concanavalin A-activated spleen cells (CAS) on the expression of various antigens, especially Ia antigens, on BALB/c B lymphoid cells, was examined. This study demonstrates the following: (i) CAS enhanced the expression of Ia antigens on four out of five BALB/c lymphoid cell lines. (ii) CAS selectively modulates the expression of Ia and H-2D, but not sIgM or viral gp70 expression, on X16C 8.5 tumor cells. The enhanced levels of Ia expression on B lymphoid tumor cells were also detected by using anti-Ia monoclonal antibodies. (iii) The molecular weight of soluble factor(s) affecting Ia and H-2 was approximately 40,000 estimated by gel filtration on a Sephadex G-200 column. (iv) Type 1 interferon but not interleukin 1, interleukin 2, or T-cell-replacing factor enhanced the expressions of Ia and H-2D antigens. (v) The activity of CAS-modulating Ia and H-2 antigens was eliminated by acidic treatment. It was concluded from this study that at least one of the factor(s) in CAS, modulating the antigenic expression of B-lymphoid cells, was interferon-like in nature. From our findings, a possible immunoregulatory mechanism by interferon was suggested: T cells, after stimulation of mitogens or antigens, secrete interferons which modulate the expression of Ia and H-2 on B cells. Then B cells, whose Ia and H-2 were modulated selectively by T-soluble factors(s), might interact with T cells much more efficiently.
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D006183:H-2 Antigens / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006863:Hydrogen-Ion Concentration; D007371:Interferon-gamma / Q000276:immunology; D007375:Interleukin-1 / Q000276:immunology / Q000494:pharmacology; D007376:Interleukin-2 / Q000276:immunology; D008211:Lymphocyte Cooperation; D008222:Lymphokines / Q000276:immunology*; D051379:Mice; D008970:Molecular Weight; D013601:T-Lymphocytes / Q000276:immunology*
D006183:H-2 Antigens; D000949:Histocompatibility Antigens Class II; D007375:Interleukin-1; D007376:Interleukin-2; D008222:Lymphokines; D007371:Interferon-gamma