Distinct microbial and immune niches of the human colon

Abstract

42Gastrointestinal microbiota and immune cells interact closely and display regional 43 specificity, but little is known about how these communities differ with location. Here, 44we simultaneously assess microbiota and single immune cells across the healthy, 45 adult human colon, with paired characterisation of immune cells in the mesenteric 46 lymph nodes, to delineate colonic immune niches at steady-state. We describe 47 distinct T helper cell activation and migration profiles along the colon and 48 characterise the transcriptional adaptation trajectory of T regulatory cells between 49 lymphoid tissue and colon. Finally, we show increasing B cell accumulation, clonal 50 expansion and mutational frequency from caecum to sigmoid colon, and link this to 51 the increasing number of reactive bacterial species. 52 53

Single-cell chromatin accessibility landscape identifies tissue repair program in human regulatory T cells

“…Whereas the relevance of murine tissue-repair Treg cells has been well established and their development described on single-cell level, the characterization of a human tissue-repair Treg counterpart remains limited. Single-cell studies have addressed human Treg cells in the context of tumors (Azizi et al, 2018;Plitas et al, 2016;Sakaguchi et al, 2020;Szabo et al, 2019) and healthy tissues (James et al, 2020;Miragaia et al, 2019;Wu et al, 2019), but little is known about the human repair Treg program.…”