MAIT cells, surveyors of a new class of antigen: development and functions

► MAIT cells recognize riboflavin derivatives originating from bacteria. ► Selection by hematopoietic thymic cells induce MAIT cell-specific features. ► MAIT cells are effector tissue targeted T cells resistant to xenobiotics. ► MAITs secrete IFN-γ and IL-17 and display context-dependent effector activities. ► Human MAITs encompass most, if not all, IL-17 producing CD8 T cells.