Comparison of Immunoresponses Between Cecal Patch Cells and Peyer’s Patch Cells Stimulated by Bacterial Components

Abstract

It is known that intestinal commensal bacteria modulate the gut immunoresponses in the small intestine. However, the precise mechanism underlying how these bacteria modulate the intestinal immune system in the large intestine, which contains most of the intestinal commensal bacteria, is poorly understood. In a previous study, we observed that dietary Bifidobacterium pseudocatenulatum JCM 7041 (Bp) was taken up into the luminal side of cecal patches (CPs) directly, and that Bp was captured by CD11c+ cells in the CP as well as in the Peyer’s patches (PPs) in the small intestine. The aim of this study was thus to clarify and compare the characteristic immunoresponses of CP and PP cells to bacterial components. The unfractionated cells or antigen-presenting cells (APCs) from both PP and CP were isolated from BALB/c mice, and co-cultured with sonicated Bifidobacterium (BIM) or lipopolysaccharide (LPS) from E.coli for 24 h or 72 h. The amounts of interleukin (IL)-12p40 and IL-10 produced were measured by ELISA. In the co-culture with BIM and LPS, CP cells and PP cells produced almost equal levels of IL-10. In contrast, PP cells produced significantly higher levels of IL-12p40 than CP cells. Furthermore, APCs from CP secreted less IL-12p40 than those from PP. In contrast, APCs of CP tended to produce higher levels of IL-10 than those of PP. These results indicate that APCs of CPs show down-regulated immune responses to bacterial components compared to APCs from PPs.