Effect of tumor growth factor-beta on NK receptor expression by allostimulated CD8(+) T lymphocytes

We have examined the influence of the immunosuppressive cytokine TGF-beta o n NK receptor expression by T lymphocytes upon allogeneic activation. Using the primary mixed lymphocyte reaction (MLR), our data show that allostimul ation induced the expression of CD94/NKG2-A on alloactivated CDS' T cells. This expression was increased in the presence of TGF-ss whereas IL-15 had n o significant effect. The blockage of CD94 and NKG2-A resulted in increased lysis of targets by alloactivated cytotoxic T cells, This increase was dep endent on the activation state of T cells. Using PCR, we also demonstrated that TGF-ss had no effect on the transcription of non-inhibitory NKG2 molec ules. The present results show that allostimulation can induce CD94 and fur ther point out the role of TGF-beta in the induction of the CD94/NKG2-A rec eptor on alloactivated T cells.