TLR7 and infection: R848 administration was previously shown to stimulate TLR7-expressing CD11c+ cells in the small intestine, inducing the expression of IL-23, which leads to IL-22 and downstream induction of antimicrobial Reg3g peptides by the intestinal epithelium.38 To determine the immune response elicited by oral administration of R848 in the large intestine prior to infection, we assessed colonic tissue gene expression levels at multiple time points following R848 treatment in uninfected mice.