Hepatic regulation of lymphocyte adhesion to, and activation on, syngeneic endothelial monolayers

Endothelial monolayers were prepared from neonatal heart or liver tissue of Lewis (Le) rats. Cells in their first passage of culture were used to investigate the short-term (1 hr at 37 degrees) binding of 51Cr-labelled Le rat lymphocytes prepared from the mesenteric lymph node (MLN), peripheral lymph node (PLN) or Peyer's patches (PP) to those endothelia, or the activation by concanavalin A (Con A) or irradiated (Lewis x Brown Norway)F1 (LBNF1), of Le cells on the monolayers after 84 hr in culture. MLN and PP showed preferential binding to, and activation on, liver endothelium compared with heart endothelium (approximately twofold difference), while the converse was seen with PLN. No inhibition of binding was seen with antibodies to intracellular adhesion molecule-1 (ICAM-1) or lymphocyte function-associated antigen-1 (LFA-1). Preincubation of endothelial cells with plasma isolated from the portal or hepatic vein of normal adult mice (5% plasma, 37 degrees for 14 hr) caused a 1.5-2-fold stimulation of binding of MLN/PP to heart endothelium, which was inhibited (> or = 75%) by anti-ICAM-1 or anti-LFA-1, and a fourfold stimulation of binding to liver endothelium, which was not inhibited by these monoclonal antibodies (< or = 25% inhibition). In contrast, antibodies to tumour necrosis factor-alpha (TNF-alpha) or interleukin-6 (IL-6) caused inhibition of activation of liver endothelium (> or = 75%), while producing little affect on activation of heart endothelium. Similar results were seen when lymphocyte activation on endothelial cells rather than adhesion cells was investigated. Our data suggest a heterogeneity in lymphocyte-endothelial interactions, which is further regulated, under physiological conditions, by the liver.