Anergic T cells exert antigen-independent inhibition of cell-cell interactions via chemokine metabolism

Due to their ability to inhibit antigen-in vitro and tissue infiltration in vivo. The induced T-cell activation in vitro and in inhibition is reversible and cell-contact vivo, anergic T cells can be considered part of the spectrum of immunoregulatory T lymphocytes. Here we report that both murine and human anergic T cells can impair the ability of parenchymal cells (including endothelial and epithelial cells) to establish cell-cell interactions necessary to sustain leukocyte migration dependent but does not require cognate recognition of the parenchymal cells to occur. Instrumental to this effect is the increased cell surface expression and enzymatic activity of molecules such as CD26 (dipeptidyl-peptidase IV), which may act by metabolizing chemoattractants bound to the endothelial/epithelial cell surface. These results describe a previously unknown antigen-independent anti-inflammatory activity by locally generated anergic T cells and define a novel mechanism for the long-known immunoregulatory properties of these cells. (C) 2003 by The American Society of Hematology.