A high number of lymphocytes constitutively associate with epithelial tissues and these are called intraepithelial lymphocytes (IELs). IELs are not restricted to classical MHC and often express  T cells receptors (TCRs). In this talk, I will discuss the capacity of  TCR+ IELs in the skin to directly sense the health status of epithelial cells and to initiate a multifaceted response to promote homeostasis and tissue repair.

By a variety of means IELs cross-communicate with epithelial cells to regulate their proliferation, differentiation, transit time through the epidermis and even DNA repair. I will particularly focus on the importance of type 2 immunity in mediating immune-surveillance and will address how IL-33 contributes to skin homeostasis via regulation of tissue-resident Treg.

Overall, the talk will provide novel information on the versatile regulation of epithelial cells by type 2 immunity which ultimately strengthens the epithelial barrier and decreases susceptibility to damage and cancer development.