VIRUS-ACTIVATED T-CELLS REGULATE EXPRESSION OF ADHESION MOLECULES ON ENDOTHELIAL-CELLS IN SITES OF INFECTION

To study the role of cell adhesion molecules in the fatal CD8(+) T-cel l mediated meningitis which is induced by intracerebral infection with lymphocytic choriomeningitis virus, the expression of relevant molecu les on inflammatory cells and local endothelium was analyzed immunohis tochemically. Most inflammatory cells were strongly positive for LFA-1 , VLA-4, Pgp-1 and ICAM-1. Expression of ICAM-1 and VCAM-1 was upregul ated on the endothelial dells in immunocompetent mice, but not in T-ce ll deficient nude mice. Analysis of mice deficient in either CD4(+) or CD8(+) T cells, revealed that not only was the inflammatory reaction dependent on the presence of CD8(+) cells, but these cells also appear ed to be required for maximal upregulation of ICAM-1 and VCAM-1 on the endothelial cells. These results indicate that virus-specific CD8(+) T cells are crucially involved in regulating-the inflammatory reaction through effects on endothelial expression of adhesion molecules.