STIMULATION OF CLONED HUMAN LYMPHOCYTES-T VIA THE CD3 OR CD28 MOLECULES INDUCES ENHANCEMENT IN VASCULAR ENDOTHELIAL PERMEABILITY TO MACROMOLECULES WITH PARTICIPATION OF TYPE-1 AND TYPE-2 INTERCELLULAR-ADHESION PATHWAYS

Perivascular accumulation of CD29+CD45R0+ memory T lymphocytes at sites of chronic inflammation such as rheumatoid synovium is commonly associated with the localized increase in the endothelial permeability. We have recently demon strated that a direct interaction between activated CD29+CD45R0+ memory T lymphocytes and vascular endothelial cells (EC) results in the increased permeability of EC. In this report, we have investigated effects on antigen‐specific T cell receptor (TcR) α/β+ human T lymphocyte clones on the endothelial permeability to albumin. Our results show that CD29+CD45R0+ cloned human T lymphocytes augment endothelial permeability by a noncytolytic process requiring surface contact between T lymphocytes and EC. Both cytolytic and noncytolytic cloned T lymphocytes were capable of augmenting endothelial permeability and this process did not involve active lysis of EC. Stimulation of T lymphocytes via the CD3/TcR or CD28 molecules resulted in significant enhancement in the ability of T lymphocytes to influence endothelial permeability. Pretreatment of T lymphocytes with monoclonal antibodies directed at either CD11a/CD18 (LFA‐1) or CD2 molecules or that of EC with monoclonal antibodies directed at either CD54 (ICAM‐1) or CD58 (LFA‐3) molecules significantly inhibited T lymphocyte‐induced enhancement in endothelial permeability, thus indicating that activated T lymphocytes utilize both type‐1 (CD11a/CD18CD54) and type‐2 (CD2CD58) intercellular adhesion pathways to augment endothelial permeability and signals received via CD3 or CD28 molecules on T lymphocytes further enhance this process. Furthermore, proinflammatory cytokines interleukin 1 and tumor necrosis factor but not interleukin 6 induced resistance in EC to T lymphocyte‐mediated effects on their permeability. Collectively, these observations may provide insights into molecular mechanism(s) underlying pathophysiology of localized chronic inflammatory responses in general and more specifically selective accumulation of chronically activated memory T lymphocytes at sites of chronic inflammation. Copyright © 1990 Wiley‐VCH Verlag GmbH & Co. KGaA