Transforming growth factor-β-induced expression of CD94/NKG2A inhibitory receptors in human T lymphocytes

✍ Scribed by Stefania Bertone; Francesca Schiavetti; Rosa Bellomo; Chiara Vitale; Marco Ponte; Lorenzo Moretta; Maria C. Mingari

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 181 KB
• Volume: 29
• Category: Article
• ISSN: 0014-2980
• DOI: 10.1002/(sici)1521-4141(199901)29:01<23::aid-immu23>3.0.co;2-y

✦ Synopsis

Different HLA class I-specific killer inhibitory receptors (KIR) are expressed in vivo by a fraction of activated T cells, predominantly CD8 + , in which they may inhibit TCR-mediated cell functions. In an attempt to identify mechanisms leading to KIR expression in T cells, we analyzed the effect of transforming growth factor-g (TGF-g ) in T cells responding to bacterial superantigens in vitro. We show that TGF-g induces the expression of CD94/NKG2A in cells responding to toxic shock syndrome toxin 1 or to other staphylococcal superantigens. Remarkably, maximal CD94 expression occurred at (low) TGF-g concentrations which have no substantial effect on lymphocyte proliferation. Maximal CD94 expression occurred when TGF-g was added shortly after the cells were placed in culture. No expression could be induced in CD94/NKG2A-negative T cell clones. Although both CD4 + and CD8 + expressed CD94, the simultaneous expression of NKG2A was mostly confined to CD8 + cells. Monoclonal antibody-mediated cross-linking of CD94/NKG2A led to an impairment of T cell triggering via CD3, as determined in a redirected killing assay using the Fc + receptor-positive P815 murine target cells.