Heterogeneity of T cells and macrophages in chlorine-induced acute lung injury in mice using single-cell RNA sequencing

Objective Chlorine (Cl2), as an asphyxiant toxicant, induced poisoning incidents and acute lung injury (ALI) occur frequently. The specific pathogenesis of Cl2-induced ALI remains unclear. Immune cells play an important role in the process of lung damage. We used single-cell RNA sequencing (scRNA-seq) technology to explore T cells and macrophages molecular mechanism.Methods Female BALB/c mice were exposed to 400 ppm Cl2 for 15 min. scRNA-seq technology was used to observe the heterogeneity of T cells and macrophages. Hematoxylin–eosin (H&E) staining was used to evaluate the degree of lung injury. Immunofluorescence was used to verify the highly expressed genes of our interest.Results A total of 5316 to 7742 cells were classified into eight different cell types. Several new highly expressed anti-inflammatory and pro-inflammatory genes were found in T cells and macrophages, which were further verified in vitro. Through the pseudotime analysis of macrophages, it was found that the expression of pro-inflammatory and anti-inflammatory genes showed opposite trends in the development of Cl2-induced ALI. This study also mapped T cells-macrophage communication and identified the development of several important receptor-ligand complexes in Cl2-induced ALI.Conclusions These findings are worthy of further exploration and provide new resources and directions for the study of Cl2-induced ALI in mice, especially in immune and inflammation mechanisms.