Since MAIT cells are found in high proportions in the gut, we hypothesized that mice lacking MR1, and therefore MAIT cells, would be more susceptible to infection with an intestinal pathogen such as Cd. Wild-type C57BL/6J and MR1-/- mice were pretreated with cefoperazone for five days then given a two-day rest prior to infection with Cd630 spores (Fig 1A). This evidence concerns the gene MR1 and infection.