Single-cell RNA sequencing reveals the transcriptional landscape and heterogeneity of macrophages in intestinal tissue of WT and CD163+ macrophage-deficient mice.
CD163 macrophages, which markedly accumulated in inflammation and tumor tissues possessed markedly immunosuppressive functions on immune cells, especially effective cells such as CD8 cells. However, the mechanism of CD163 macrophages in regulating immune responses remains to be illusive. Using single cell-sequence techniques, we identified CD163 macrophage subset in the colon tissues. Meanwhile, we also characterized CD163 macrophage associated immune cell populations and subpopulations in mouse colon tissues. We found that CD163+ macrophage subset in the colon was related to gut microbiota. Deletion of CD163+ macrophage subset could markedly increase the proportions of the immune cell subsets such as CD8 and NK cells. Mechanistically, gut microbiota mediated CD163+ macrophage subpopulations can down-regulate CD8 and NK cells through inhibitory molecules CD94/NKG2a (Kird1/Kirc1 in mice) and their ligand HLA-E /QA-1 (Human/mice) on the surface of CD163+ macrophages. Overall design: 10X Genomics scRNA-seq was performed to better assess immune cell heterogeneity in gut lamina propria (LP).