MR1 and infection: MAIT cells have been shown to accumulate in the lungs of mice infectedwith S. typhi and this accumulation was dependent on MR1 and thesize of bacterial inoculum.84 In addition, differentiation of monocytes to DCs in the lungs followingFrancisella tularensis infection and subsequent recruitment ofCD4+ T cells to the lung was mediated by MAIT cells.85 IL-12p40-, MR1- or MAIT cell-deficient mice lacked the ability to control BCGor F. tularensis infections and quickly succumbed to low doses ofBCG infection.4,86