IL-17RC^−/− mice are susceptible to oropharyngeal candidiasis equivalently to IL-17RA^−/− or Th17^−/− mice. A, IL-17RC^−/− mice are susceptible to OPC. IL-17RC^−/−, IL-17RC^+/−, or age- and sex-matched WT mice were infected orally with C. albicans,. Five days after inoculation, mice were sacrificed and the oral fungal burden in the tongue was assessed, normalized to weight of tongue tissue. As positive controls for infection, WT and IL-17RC^−/− mice were treated with cortisone acetate to cause susceptibility to infection. As a negative control, IL-17RC^−/− mice were sham-infected with PBS. Bars indicate the mean fungal load per group. B, IL-17RC^−/−, IL-17RA^−/−, and IL-23^−/− mice show similar susceptibilities to OPC. IL-17RC^−/−, IL-23p19^−/−, and IL-17RA^−/− mice were subjected to OPC in the same experiment as outlined above. C, Polymorphonuclear cell recruitment is defective in IL-17RA^−/− and IL-17RC^−/− mice. Periodic-acid Schiff-stained images of tongue tissue in infected mice were analyzed for polymorphonuclear cell recruitment in a blinded analysis.