Abstract:

Objective To investigate the correlation between peripheral blood myeloid-derived suppressor cells (MDSCs) levels and the severity of necrotizing enterocolitis (NEC), and the biological characteristics of MDSCs in NEC infants. Methods The single-cell sequencing dataset of peripheral blood from NEC patients was downloaded from the GEO database and analysed by quality control, batch correction, clustering dimensionality reduction and cell type annotation. The number and proportion of MDSCs in the peripheral blood of NEC patients at different disease stages were calculated. Subsequently, MDSCs subsets were extracted, differentially expressed genes and enrichment pathways were analysed, and the expression of MDSC immunosuppressive function, apoptosis and chemotaxis related molecules were compared. Results As the severity of NEC increased, the corresponding number and proportion of MDSCs gradually decreased. Compared with stage II NEC patients, upregulated genes in MDSCs of stage III NEC patients were enriched in multiple pathways, such as positive regulation of leukocyte activation and negative regulation of locomotion. And there was no significant difference in immunosuppressive function and apoptotic pathway activation between MDSCs from stage II and III NEC patients, whereas the expression of chemokine receptor CXCR1 was significantly decreased in MDSCs from stage III NEC patients. Conclusion The number of MDSCs in the peripheral blood of NEC patients was inversely correlated with the severity of NEC. And the reduction of MDSCs in stage III NEC patients could be attributed to the downregulated expression of CXCR1.

Key words: necrotizing enterocolitis, myeloid-derived suppressor cells, CXCR1, child