Uveitis is a severe inflammatory disease that can cause visual impairment. Recently, activated [Formula: see text] T cells were proved to play a central role in the development of experimental autoimmune uveitis (EAU). However, the mechanism underlying [Formula: see text] T-cell activation in EAU is incompletely known. In this study, we determined the percentage changes in and the phenotypes of [Formula: see text] T cells and dendritic cells (DCs) obtained from the spleens of immunized C57BL/6 (B6) mice, an animal model of EAU. We found that the number of [Formula: see text] T cells and DCs obviously increased during the inflammation phase of EAU (days 16–20 of our experiment), and that during this time, [Formula: see text] T cells expressed high levels of CD69 and the integrin lymphocyte function–associated antigen-1 (LFA-1) and secreted high levels of interleukin (IL)-17A. Moreover, DCs obtained during this phase expressed high levels of CD80, CD83, CD86, and intracellular cell adhesion molecule-1 (ICAM-1). Furthermore, we studied the interaction between DCs and [Formula: see text] T cells by using flow cytometry and confocal microscopy in order to determine whether DCs affected [Formula: see text] T-cell activation in vitro. Co-cultures of the two types of cells showed that DCs induced high levels of CD69, LFA-1, and IL-17A in [Formula: see text] T cells. Imaging studies revealed contact between the DCs and [Formula: see text] T cells. This interaction was mediated by the accumulation of ICAM-1 and LFA-1 at the interface of DCs-[Formula: see text] T cells. Thus, the activation of [Formula: see text] T cells in EAU was promoted by DCs interacting with [Formula: see text] T cells.
Retinoic Acid Inhibits CD25+Dendritic Cell Expansion and γδ T-Cell Activation in Experimental Autoimmune Uveitis