Orally induced, peptide-specific gamma/delta TCR(+) cells suppress experimental autoimmune uveitis

We investigated the role of gamma/delta TCR(+) T cells in induction and suppression of the T cell-mediated disease experimental autoimmune uveitis. Disease induction was studied in Lewis rats perinatally depleted of alpha/beta or gamma delta TCR(+) subpopulations. Depletion of alpha/beta TCR(+) cells completely abrogated disease, whereas treatment with anti-gamma/delta antibodies had no influence on onset or intensity of uveitis. However, adoptively transferred gamma/delta(+) cells from orally tolerized rats could mediate suppression of uveitis in an antigen-specific fashion. Uveitis induced by a peptide derived from the uveitogenic retinal soluble antigen (S-Ag) was suppressed by gamma/delta(+) cells from rats orally tolerized with;the same peptide as well as HLA peptide B27PD. This disease ameliorating effect could also be observed when rats were fed with the HLA peptide before immunization with S-Ag peptide. Transfer of <alpha/beta(+) T cells from the same donors as well as gamma/delta(+) or alpha/beta(+) cells from animals fed with control peptide had no ameliorating effect.