Intraepithelial lymphocytes: lessons in immunoregulation from 'landlocked' T cells

During his award Professor Hayday will seek to update the current 'textbook' definition of the roles and actions of T cells. This research will place new emphasis on the fact that many tissues are constitutively replete with 'landlocked' T cells that Professor Hayday's laboratory has shown to respond very rapidly to tissue perturbation by infection and/or non-microbial stress such as physico-chemical insults. Pursuing the observation that the composition of the T-cell compartments differs from one anatomical site to another, Professor Hayday's hypothesis is that there are organ-specific epithelial molecules that ‘select for’ their cognate T-cell compartments. In support of this, the research group has identified a novel molecule, Skint1, expressed uniquely in thymic epithelium and in epidermal keratinocytes, that is required specifically for the development of the epidermal skin T-cell compartment. This research will test whether this is a generalisable phenomenon by tracking the identity of novel intestinal epithelial determinants of the gut T-cell repertoire. Such molecules may offer new insight into gut inflammation and interactions with the microbiome, and set a foundation for understanding T-cell compartments at other body surfaces.