Regulation of B lymphocyte responses to IL-4 and IFN-gamma by activation through Ly-6A/E molecules.
The Ly-6 family of cell surface molecules has previously been shown to participate in T cell activation. We show that Ly-6A/E proteins also modulated the response of normal B lymphocytes in three separate in vitro assays. First, unfractionated or small resting B cells proliferated when cultured with IFN-gamma, IL-4, and an anti-Ly-6A/E mAb. Second, this anti-Ly-6A/E mAb restored B cell proliferation responses that were inhibited when coculturing the B cells in IFN-gamma, IL-4, and anti-IgM. Third, anti-Ly-6A/E specifically up-regulated the cell surface expression of its own Ag, and this response was dependent upon co-stimulation with IFN-gamma. Mixing of T and B cells in culture suggested that T cells did not contribute substantially to the B cell proliferative response. Moreover, up-regulation of Ly-6A/E was observed for one B cell lymphoma, WEHI-231. Therefore, it appeared that modulation of B cell function by anti-Ly-6A/E was due to a direct effect of the mAb binding to the B cells. Taken together, these data suggest Ly-6A/E proteins are functional on B cells and may play a regulatory role in B cell activation.
Codias
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EK
Department of Microbiology and Immunology, University of Miami School of Medicine, FL 33101.
Malek
T R
TR
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000950:Antigens, Ly / Q000276:immunology* / Q000378:metabolism; D001402:B-Lymphocytes / Q000276:immunology*; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D007158:Immunologic Techniques; D007371:Interferon-gamma / Q000494:pharmacology*; D015847:Interleukin-4 / Q000494:pharmacology*; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D015854:Up-Regulation
D000911:Antibodies, Monoclonal; D000950:Antigens, Ly; D007140:Immunoglobulin Fab Fragments; D015847:Interleukin-4; D007371:Interferon-gamma