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

Human T lymphocyte transendothelial migration (TEM) was examined in response to chemokines across cytokine‐activated endothelium. Monocyte chemotactic protein‐1 (MCP‐1), RANTES, and macrophage inflammatory protein‐1α (MIP‐1α) induced TEM by memory T cells, while stromal cell‐derived factor‐1 (SDF‐1) induced TEM by both naive and memory T cells. Tumor necrosis factor α (TNF‐α) and interleukin‐1 (IL‐1) increased endothelial adhesion molecule (CAM) expression, whereas interferon‐γ (IFN‐γ) induced little up‐regulation of CAM. However, both TNF‐α and IFN‐α strongly facilitated T cell migration, which was completely inhibited by pertussis toxin and both greatly increased TEM to RANTES, MIP‐1α, 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 appears to be independent of the increase in endothelial CAM expression. G‐protein‐linked stimuli may play an important part in T cell TEM across cytokine‐activated endothelium. J. Leukoc. Biol. 67: 825–833; 2000.