Adherence of blood T cells to rat microvascular endothelial cells. Comparative studies of T lymphocytes isolated from various tissues.

Lymphocytes isolated from various tissues exhibit different magnitudes of adherence to endothelial cells (EC) in vitro. Nevertheless, a good correlation between the lymphocyte adherence to EC in vitro and their migratory properties to sites of inflammation in vivo was found. The main goal of this study was to compare, using unstimulated and IFN-gamma-, TNF-alpha- or LPS-pretreated EC, the adherence of T cells isolated from blood (BTC), with the adherence of T lymphocytes obtained from other tissues. The results show that BTC belong to poorly adhering cells. However, their adherence was increased about 3-fold, when EC were pretreated with IFN-gamma, TNF-alpha or LPS. This adherence was very similar to that observed for lymph node T cells (LNTC) and 2-3 times lower than the adherence of spleen T cells (SpTC) and peritoneal exudate T cells (PETC). In some experiments, T lymphocytes were incubated for 1 h with concanavalin A (Con A) and this led to the highest increase of BTC adherence, but the enhancement of the adherence was significantly smaller than the increase noted for SpTC and PETC. The differences in the adherence of lymphocytes isolated from various tissues may suggest that different adhesion molecules are responsible for their binding to EC.