The preferential accumulation of helper‐inducer T lymphocytes in inflammatory lesions: evidence for regulation by selective endothelial and homotypic adhesion

Abstract

The mechanisms which lead to the accumulation of T lymphocytes into inflammatory lesions are not clearly understood. We have previously shown that synovial CD4 T lymphocytes are mostly CDw29UCHL1 (helper‐inducer cells) and very few carry the CD45R antigen which identifies the suppressor‐inducer subset. Synovial CD8 cells are also CDw29UCHL1CD45R−. In the present study, lymphocytes from pleural and peritoneal inflammatory infiltrates were shown to have a similar phenotypic pattern. Furthermore, it was demonstrated that the CDw29UCHL1 subset had a greater ability than CD45R cells to adhere to endothelial cells and to form homotypic clusters. Differential surface expression of LFA‐1 on the two subsets was also shown, but this could not account for the demonstrated adhesion differences. Differences in adhesion between CDw29/UCHL1 and CD45R cells may explain the preferential accumulation of CDw29/UCHL1 cells in inflammatory infiltrates and underlie some of the functional differences between cells taken from sites of chronic inflammation and those from peripheral blood.