Dynamic analysis of intrahepatic T cells reveals a unique group of restorative Cxcr3+ tissue-resident CD4 T cells in acute liver injury.

Acetaminophen (APAP) stands as one of the most prevalent triggers of drug-induced acute liver injury (ALI). The intricate modulation of immune system activation and inflammatory cascades by hepatic immune cells is paramount in managing liver injury and subsequent restoration. In this study, we employed an integrative approach that fused our proprietary flow cytometry analyses across various time points post-APAP injury with publicly available single-cell RNA sequencing (scRNA-seq) datasets, encompassing time-series data from liver tissue of mice subjected to APAP intoxication. This allowed us to delve into the dynamics of T cell profiles during APAP-induced ALI. Our comprehensive analyses unveiled the intricate temporal shifts in intrahepatic T cell populations across different phases following APAP-induced ALI. Notably, we observed a persistent augmentation of intrahepatic CD4+ T cells post-APAP injury. Amongst these, a distinct population of restorative Cxcr3+ tissue-resident CD4+ T cells emerged. Inhibition of CXCR3 using a neutralizing antibody exacerbated APAP-induced liver function impairment and hepatocyte death. Furthermore, we identified that the Cxcr3+ tissue-resident CD4+ T cells were tightly regulated by intrahepatic ''Lgals9-Cd45'' and 'CXCL13-Cxcr3' signaling pathways. These discoveries underscore the novel protective function of CXCR3, a vital biological macromolecule, in mitigating APAP-induced ALI, and may shed lights on new therapeutic strategies targeting this condition.