Single-cell transcriptomic profiling reveals functional heterogeneity and regulatory programs of neutrophils in...

Autoimmune uveitis (AU) is a vision-threatening ocular autoimmune disease. Previous studies have reported increased perivascular neutrophil infiltration during AU progression, yet the precise functional roles of these cells remain incompletely understood.

This study employed single-cell RNA sequencing (scRNA-seq) to systematically characterize neutrophils in the retina of experimental autoimmune uveitis (EAU) mice and to elucidate their regulatory mechanisms. scRNA-seq data were obtained from the mouse retinal samples of EAU and subjected to preprocessing, cell type annotation, neutrophil activation states analysis, differential gene expression analysis, functional enrichment, and transcription factor network inference, enabling a comprehensive exploration of neutrophil heterogeneity and functional features.

EAU retinas exhibited markedly enhanced immune cell infiltration, with a significant increase in neutrophil proportion. Highly expressed neutrophil genes were enriched in transcription, translation, metabolism, and phagocytosis, and implicated key signaling pathways, including TNF, NF-κB, and MAPK, highlighting inflammatory responses as their principal function. Functional modules displayed a coordinated regulatory pattern. Neutrophils were further classified into two functionally distinct activation states: a dominant pro-inflammatory state (76.7%) and an anti-inflammatory/reparative state (23.3%), which differed significantly in gene expression, functional enrichment, and surface receptor profiles. Transcription factor network analysis identified upregulated factors such as Jun and downregulated factors such as Stat6, indicating their respective regulatory roles in pro-inflammatory and anti-inflammatory activation states. Several downstream target genes, including Arpp19 and Lyrm2, were co-regulated by multiple transcription factors.

This study reveals the heterogeneous features and regulatory networks of retinal neutrophils in EAU mice, clarifies differences between these neutrophil activation states, and identifies key regulatory molecules. These findings provide a theoretical foundation for understanding the pathogenesis of uveitis and for the development of precise therapeutic targets.