Usage of TCR Vγ2(+) T Lymphocytes in Experimental Autoimmune Uveoretinitis

Experimental autoimmune uveoretinitis (EAU) is a T cell mediated autoimmune disease that serves as a model of human intraocular inflammatory disease (uveitis). It is initiated in susceptible animals by immunization with retinal antigens, such as interphotoreceptor retinoid binding protein (IRBP) and S-Antigen (SAg) or by adoptive transfer of ocular Ag-specific uveitogenic T cells. Previous studies of T cell receptor (TCR) usage by uveitogenic T cells have implicated Vβ8(+) -expressing T cells in the pathogenesis of EAU. Here, the authors have analyzed the TCR Vγ repertoire in the retinas of Lewis rats with and without EAU as well as the repertoire of several SAg- or IRBP-specific T cell lines. They detected Vγ2 transcripts in all four pathogenic lines and in the retinas of Lewis rats with EAU but not in the two non-pathogenic lines nor in the retinas of naive rats. Vγ7 transcripts were detected in RNAs obtained from the retina, regardless of whether the rat had EAU or not. However, the authors could not detect Vγ4, Vγ5 or Vγ6 TCR transcripts in any of the samples analyzed. Taken together, their data suggests a correlation between recruitment of Vγ2(+) T cells and EAU pathogenesis.