Tumor escape mechanism governed by myeloid-derived suppressor cells.

T-cell nonresponsiveness is a critical factor in immune escape and myeloid-derived suppressor cells play a major role in organizing this phenomenon. Recent findings indicate that myeloid-derived suppressor cells can induce antigen-specific CD8(+) T-cell tolerance through a posttranslation mechanism which involves modification (nitration) of CD8 and the T-cell receptor itself on the T-cell surface. Elucidation of this mechanism of T-cell tolerance offers new opportunities for therapeutic corrections of immune escape in cancer.