Single-cell profiling reveals a conserved role for hypoxia-inducible factor signaling during human craniotomy infection.

Neurosurgeries complicated by infection are associated with prolonged treatment and significant morbidity. Craniotomy is a common neurosurgical procedure; however, the cellular and molecular signatures associated with craniotomy infection in human subjects are unknown. A retrospective study of over 2,500 craniotomies reveals diverse patient demographics, pathogen identity, and surgical landscapes associated with infection. Leukocyte profiling in patient tissues from craniotomy infection characterizes a predominance of granulocytic myeloid-derived suppressor cells that may arise from transmigrated blood neutrophils, based on single-cell RNA sequencing (scRNA-seq) trajectory analysis. Single-cell transcriptomic analysis identifies metabolic shifts in tissue leukocytes, including a conserved hypoxia-inducible factor (HIF) signature. The importance of HIF signaling was validated using a mouse model of Staphylococcus aureus craniotomy infection, where HIF inhibition increases chemokine production and leukocyte recruitment, exacerbating tissue pathology. These findings establish conserved metabolic and transcriptional signatures that may represent promising future therapeutic targets for human craniotomy infection in the face of increasing antimicrobial resistance.