A seminar hosted by the School of Cellular and Molecular Medicine
Abstract: The tissues are the site of many of the most important immunological reactions, yet the biology of immunology in the tissues has remained relatively opaque. Recent studies have identified Foxp3+ regulatory T cells (Tregs) in several non-lymphoid tissues. These tissue-resident populations have been ascribed unique characteristics based on phenotypic differences from lymphoid Tregs, RNA-Seq profiles, and TCR usage. Using high-depth cell profiling, kinetic analysis and functional TCR testing, we instead observed that there is a single pool of pan-tissue Tregs with little or no homing preference for their tissue of origin. While tissue Tregs constitute a single pool of broadly self-reactive activated Tregs that patrols non-lymphoid tissues, the protective impact on particular organs can be amplified by changing the tissue Treg niche size. Using a gene delivery system, we demonstrate strong protection from neuroinflammation across multiple neurological injury and disease models when the tissue Treg niche size is expanded in the brain.