A Single-cell Atlas Of Tumor-associated Macrophage In Colorectal Cancer

Tumor-associated macrophages are a type of macrophages that infiltrate tumor tissues and are the most immune cells in the tumor microenvironment.In the environment of colorectal cancer,macrophages not only infiltrated the tumor microenvironment,but also exposed to the complex environment of the intestine,showing great heterogeneity.We induced ApcMin heterozygous mice through AOM/DSS and successfully established a mouse-related connective cancer tumor model.After obtaining the tumor,we prepared a single cell suspension by enzyme digestion.First,single-cell lesions were performed on mouse tumors and tissues adjacent to cancer,and then flow cytometry was used to sort out CD11 b + cells in the tumors,and then single-cell transcriptome selection was performed.We got a total of six sets of data.Through separate analysis and combined analysis of the six sets of data,the gene expression characteristics are analyzed,and through a series of visual analysis,the heterogeneity between different cell clusters is analyzed.We found that these cell clusters basically arranged monocytes,and we also characterized two CX3CR1 + cell groups,whose expression characteristics are similar to the mutation characteristics of monocyte-derived colonic macrophages.We also found that many macrophage clusters express the characteristics of M1 and M2 macrophages at the same time,which is in the intermediate state of M2/M2 cell type.Based on the expression of Vegfa,we clustered macrophages into high,medium and low categories.Vegfa-expressed cell clusters are highly expressed while macrophage clusters have phenotypic characteristics.TLR,NLR and other metabolic related genes recognize receptors and NF-?B signaling pathway related genes through pattern recognition.Some cell clusters also express metabolic bodies and NF-?B negative regulatory genes,and some macrophage co-express T cell costimulatory factors and T cell immunosuppressive factors.Through single cell transcriptome targeting technology,we synthesized the tumor-associated macrophage map of colorectal cancer,which provides a reference for understanding the distribution of macrophages in the tumor microenvironment and related immunotherapy.