S antigen specific effector T cell activation detected by cytokine flow cytometry.

BACKGROUND/AIMS Effector T cell activation is particularly important in the initiation of autoimmune uveitis. This pilot study seeks to demonstrate activation of human peripheral effector T cells in response to the uveitis candidate autoantigen, retinal S antigen (SAg), using cytokine flow cytometry (CFC). METHODS Peripheral blood mononuclear cell (PBMC) suspensions from uveitis patients and controls were stimulated with bovine SAg. Activation responses were detected by CFC. RESULTS Electronic gating enabled analysis of CD69+, IFN-gamma+ CD4+ lymphocytes. An SAg specific response was detectable in four of 13 patients and four of eight controls. CONCLUSION SAg specific, peripheral, effector T cell activation can be detected by CFC. Similar levels of responsiveness were seen in patient and control groups. More detailed cytokine profiling may demonstrate functional differences between the groups.