CCL21- but not PMA-induced integrin activation under static conditions is impaired in Tyr AG490–treated lymphocytes.

Adhesion assays were carried out and analyzed as described in “Materials and methods.” (A) Kinetics of CCL21-stimulated adhesion of lymphocytes on VCAM-1 in control (DMSO)– and Tyr AG490–treated lymphocytes (n = 3; mean ± SEM). ♦ represents control; ▵, Tyr AG490. (B) CCL21-stimulated adhesion of lymphocytes on ICAM-2 in control- and Tyr AG490–treated lymphocytes at 0 and 2 minutes after CCL21 addition (n = 3; mean ± SD). ■ represents t = 0 minutes; ▪, t = 2 minutes. (C) PMA-induced lymphocyte adhesion on VCAM-1. Adhesion was determined 6 minutes after PMA addition. PMA-induced lymphocyte adhesion is dependent on precoated integrin ligands (not shown) (n = 3; mean ± SD). ■ represents − PMA; ▪, + PMA. All asterisks indicate P < .05.