Single-cell RNA seq reveals the transcriptional landscape and heterogeneity of macrophages in murine gut tissues

CD11b+ cell populations, especially macrophages are highly heterogeneous tissue resident immune cells in both mice and human. Exact subsets and their phenotype remain unknown. We here analyzed gut CD11b+ cell populations using scRNA-seq in normal, inflamed and Nlrc4 deficient mice. There existed twelve CD11b+ cell populations and subsets in SPF mice. These CD11b+ subsets were changeable dependent on inflammation and gut environment. We found consistent high expression of Ly6C, Cd62L, previously undescribed Trem1 and Ccr7 in Ly6Chigh macrophages and Cd206 and Cx3cr1 in Ly6Clow/neg cell population in different mice. However, signature genes showed that resident macrophages but not inflammatory macrophages were highly conserved in normal and inflamed mice. Gut microbiota play a role in accumulation and differentiation of gut macrophages. Both Ly6Chigh and Ly6Clow macrophages in intestine and colon tissues are similar. These uncover the transcriptional landscape and phenotypic heterogeneity of CD11b+ cells, especially macrophages in gut tissues. Overall design: 10X Genomics scRNA-seq was performed to better assess immune cell heterogeneity in gut lamina propria (LP).