Uncovering common transcriptional features shared by mature PMN-MDSCs and tumor-associated neutrophils in humans

In this study, we performed single-cell transcriptomic profiling of mature PMN-MDSCs (mPMN-MDSCs) from non-small cell lung cancer (NSCLC) patients and identified a distinct cell cluster (NSCLC c6) exhibiting immunosuppressive and protumor features. Comparative analysis with publicly available single-cell RNA sequencing (scRNA-seq) datasets of tumor-associated neutrophils (TANs) revealed shared transcriptomic features between the identified NSCLC mPMN-MDSC and TAN clusters. These transcriptomic features included the expression of common genes, activation of the hypoxia signaling pathway, and metabolic reprogramming. Additionally, scRNA-seq analysis of mature immunosuppressive neutrophils from G-CSF-treated donors (GDs) – which are a reliable model of circulating mPMN-MDSCs - demonstrated similar dysregulation of hypoxia and metabolic pathways, further reinforcing the existence of transcriptomic similarities between circulating mPMN-MDSCs and TANs. Total CD66b+ low-density neutrophils (LDNs) and normal-density neutrophils (NDNs) from the peripheral blood of NSCLC patients (n =6) and G-CSF-treated donors (GDs; n=6), as well as total CD66b+ NDNs from the peripheral blood of healthy donors (HDs; n=8), were isolated by magnetic bead selection with fluorescence-conjugated anti-CD66b mAbs and processed with BD Rhapsody Single-Cell Analysis System for scRNA-seq. Publicly available single-cell RNA sequencing (scRNA-seq) datasets of TANs were utilized for comparative analyses.