A Single-Cell Landscape of Human Liver Transplantation Reveals a Pathogenic Immune Niche Associated with Early Allograft Dysfunction

Liver transplantation (LT) is the standard therapy for individuals afflicted with end-stage liver disease. Despite notable advancements in LT technology, the incidence of early allograft dysfunction (EAD) remains a critical concern, exacerbating the current organ shortage and detrimentally affecting the prognosis of recipients. Unfortunately, the perplexing hepatic heterogeneity has impeded characterization of the cellular traits and molecular events that contribute to EAD. Herein, we constructed a pioneering single-cell transcriptomic landscape of human transplanted livers derived from non-EAD and EAD patients, with 12 liver samples collected from 7 donors during the cold perfusion and portal reperfusion stages. Comparison of the 75 231 cells of non-EAD and EAD patients revealed an EAD-associated immune niche comprising mucosal-associated invariant T cells, granzyme B+ (GZMB+) granzyme K+ (GZMK+) natural killer cells, and S100 calcium binding protein A12+ (S100A12+) neutrophils. Moreover, we verified this immune niche and its association with EAD occurrence in two independent cohorts. Our findings elucidate the cellular characteristics of transplanted livers and the EAD-associated pathogenic immune niche at the single-cell level, thus, offering valuable insights into EAD onset.