IRG1 Promotes Neutrophil Reverse Migration and Alleviates Local Inflammation

Polymorphonuclear neutrophil (PMN) infiltration at inflammatory site plays a critical role in inflammation. PMN reverse migration (rM) describes the phenomenon that PMNs migrate away from inflammatory site back into the vasculature, and its role within inflammatory scenarios remains to be fully determined. This study aimed to investigate the mechanism underlying PMN rM and its role in inflammation. First, we demonstrated PMN rM in a mouse model of LPS-induced acute lung inflammation. By single-cell RNA sequencing (scRNA-seq), we demonstrated that reverse migrated (rM-ed) PMNs in blood expressed high level of immuneresponsive gene 1 (Irg1), the encoding gene of cis-aconitate decarboxylase (ACOD1). BALF and blood were collected from mice treated with LPS for 0, 6, and 24 h. CD45-positive cells in the BALF and blood were sorted for further scRNA-seq. The scRNA-seq libraries were generated by using Chromium Single Cell 3’ Library (10x Genomics) according to the manufacturer’s protocol.