The goal of this proposal is to define the key events ongoing in the thymus that shape the repertoire of autoreactive T cells. For this purpose, we will exploit a novel model system in which thymi from NOD female mice of varying ages are transplanted under the kidney capsule of NOD.scid recipients resulting in T cell reconstitution of the periphery. Thymi prepared from fetal and newborn NOD donors produce CD4+ and CD8+ T cells characterized by a type 1 phenotype. Importantly, the NOD.scid recipients develop overt diabetes, in addition to thyroiditis. In marked contrast, NOD.scid mice transplanted with thymi from 4 week-old or older NOD donors develop severe colitis but remain free of diabetes and thyroiditis. We hypothesize that age- dependent events regulate the efficacy of thymic positive and negative selection that in turn promote the temporal development of pathogenic T precursors.
Three Specific Aims have been established to determine the mechanisms regulating the temporal development of T cell tissue-specificity. The first will determine how age-dependent thymic events shape the repertoire of autoreactive T precursors. The second Specific Aim will determine the cellular events ongoing in the thymus that mediate the temporal development of T precursors mediating autoimmunity and colitis. The final Specific Aim will ascertain the contribution of genetic background and thymic expressed tissue antigens in the temporal development of tissue-specific T cells. In this way, novel insight will be gained into the critical events that shape the repertoire of autoreactive thymocytes.
Type 1 diabetes and other tissue-specific autoimmune diseases are mediated by T cells. The critical events that promote development of autoreactive T cells, however, remain poorly understood. This proposal employs a novel model system to define the cellular and molecular events that regulate the development of autoreactive T precursors in the thymus.
|Spidale, Nicholas A; Wang, Bo; Tisch, Roland (2014) Cutting edge: Antigen-specific thymocyte feedback regulates homeostatic thymic conventional dendritic cell maturation. J Immunol 193:21-5|
|He, Qiuming; Morillon 2nd, Y Maurice; Spidale, Nicholas A et al. (2013) Thymic development of autoreactive T cells in NOD mice is regulated in an age-dependent manner. J Immunol 191:5858-66|