Il17ra−/− mice develop less inflammation in response to S. rectivirgula exposure. A, Representative H&E staining of lungs from Il17ra−/− mice repeatedly treated with S. rectivirgula or PBS for 4 consecutive weeks is shown. Data shown represent at least four mice from at least two separate experiments (×40). B, Il17ra−/− mice treated with S. rectivirgula for 4 consecutive weeks have decreased numbers of total lung cells, macrophages, lymphocytes, and CD4+ and CD8+ T cells compared with wt C57BL/6 mice. Data shown represent at least five mice from at least two separate experiments.