Regulation of chemokine-induced transendothelial migration of T lymphocytes by endothelial activation: differential effects on naive and memory

Abstract: Human T lymphocyte transendothelial migration (TEM) was examined in response to chemokines across cytokine-activated endothe-lium. Monocyte chemotactic protein-1 (MCP-1), RANTES, and macrophage inflammatory pro-tein-1a (MIP-1a) induced TEM by memory T cells, while stromal cell-derived factor-1 (SDF-1) in-duced TEM by both naive and memory T cells. Tumor necrosis factor a (TNF-a) and interleukin-1 (IL-1) increased endothelial adhesion molecule (CAM) expression, whereas interferon-g (IFN-g) induced little up-regulation of CAM. However, both TNF-a and IFN-g strongly facilitated T cell migra-tion, which was completely inhibited by pertussis toxin and both greatly increased TEM to RANTES, MIP-1a, and SDF-1 selectively of memory but not naive T cells. Thus, the dual selective effect on memory T cells of endothelial activation and these chemokines promotes the preferential recruitment of memory T cells to inflammatory sites. However, the enhanced chemokine-induced migration by memory T cells across activated endothelium ap-pears to be independent of the increase in endothe-lial CAM expression. G-protein-linked stimuli may play an important part in T cell TEM across cytokine-activated endothelium. J. Leukoc. Biol