TH17, TH22 and TReg cells are enriched in the healthy human cecum

Abstract

There is increasing evidence that dysregulation of CD4+ T cell populations leads to intestinal inflammation, but the regional distribution of these populations throughout the intestinal tract in healthy individuals remains unclear. Here, we show that TH17, TH22 and TReg cells are enriched in the healthy human cecum compared to the terminal ileum and sigmoid colon, whereas TH1 and TH2 cells do not significantly vary by location. Transcriptional profiling analysis of paired pinch biopsies from different regions of the intestine identified significant differences in the metabolic state of the terminal ileum, cecum, and sigmoid colon. An increased proportion of TH17 cells was positively associated with expression of resistin (RETN) and negatively associated with expression of trefoil factor 1 (TFF1). These results suggest that CD4+ T helper cells that are important in maintaining mucosal barrier function may be enriched in the cecum as a result of metabolic differences of the surrounding microenvironment. © 2012 Wolff et al.