| Abstract: |
Surface molecules encoded by the murine Ly‐6 locus can transduce triggering signals in T cells and thus may play important roles in T cell function. Previously, we found that Ly‐6 molecules are up‐regulated by interferon (IFN)‐α/β in resting T cells. Here, we examined the possible influence of IFN‐γ on these molecules. Purified T cells from C57BL/6 (Ly‐6.2) and BALB/c (Ly‐6.1) mice were incubated in vitro with recombinant murine IFN‐γ and the expression of Ly‐6 antigens was measured by flow cyto‐fluorometry. It was found that both Ly‐6A/E and T cell‐activating protein (TAP) molecules are markedly enhanced while Ly‐6C is less affected. Under the same conditions, other T cell surface molecules showed no or marginal changes. The effect of IFN‐γ on Ly‐6A/E and TAP expression reached a maximum with as little as 10 U/ml and required only 18–24 h of incubation. Moreover, the enhancement of Ly‐6A expression induced by IFN‐γ was stable for at least 5 days. Analysis of T cell subsets further revealed that IFN‐γ‐induced augmentation of Ly‐6A (C57BL/6 mice) involves both Lyt‐2+ and L3T4+ cells while the increase of Ly‐6E (BALB/c mice) is more pronounced in Lyt‐2+ cells. The functional consequence of these phenotypic alterations was evaluated by studying the mitogenic responses of T cells to antibody‐mediated Ly‐6 cross‐linking in the presence of phorbol myristate acetate. Pretreatment of resting T cells with IFN‐γ dramatically increased the responses to anti‐Ly‐6A and anti‐Ly‐6E monoclonal antibodies. IFN‐γ treatment also boosted the stimulation induced by anti‐TAP monoclonal antibody when this stimulation was performed under suboptimal conditions. Therefore, IFN‐γ selectively up‐regulates the Ly‐6A/E and TAP activation pathways in resting T cells. We speculate that this effect may contribute to the immunoregulatory activities of IFN‐γ. Copyright © 1987 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim |
| Keywords: |
nonhuman; t lymphocyte; t-lymphocytes; animal cell; mouse; phenotype; animals; mice; cells, cultured; in vitro study; dose-response relationship, drug; time factors; immunoregulation; monoclonal antibody; lymphocyte activation; antibodies, monoclonal; gamma interferon; antigens, ly; ly antigen; antigens, surface; phorbol 13 acetate 12 myristate; antigens, differentiation, t-lymphocyte; lymphocyte subpopulation; beta1 interferon; interferon type ii; antigens, cd27; concanavalin a; recombinant dna; alpha1 interferon
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