The role of CD44, CD45, CD45RO, CD46 and CD55 as potential anti‐adhesion molecules involved in the binding of human tonsillar T cells to phorbol 12‐myristate 13‐acetate‐differentiated U‐937 cells

In this study, we have shown that human tonsillar T cells adhere to phorbol 12-myristate 13-acetate(PMA)-differentiated U-937 cells. To examine the molecular mechanisms involved, the effect of a panel of monoclonal antibodies upon this adhesion was assessed in a quantitative binding assay. Antibodies against LFA-1 and ICAM-1 inhibited binding, directly implicated these molecules in T cell-PMA-induced U-937 adhesion. Furthermore, the adhesion was magnesium but not calcium dependent. Of the remaining antibodies that were tested, none of those against CD2, LFA-3, Mac-1, p150,95, CD43, CD45RA or CD56 affected binding. However, antibodies against CD44, CD45, CD45RO, CD46 and CD55 enhanced binding suggesting an anti-adhesive role for these molecules during U-937-T cell interaction.