Single-cell transcriptomics reveals the alteration of peripheral blood mononuclear cells driven by sepsis

Background: Sepsis is a serious systemic inflammatory response syndrome caused by infection, with an extremely high mortality rate. Peripheral blood mononuclear cells (PBMCs) played a key role in the immune response against infection, whose components and functions were altered radically in Sepsis. Here, we wondered to characterize the alteration of PBMCs in sepsis at the single-cell transcriptional level. Methods: We isolated PBMCs from seven septic patients and four donors. Based on BD Rhapsody, PBMCs were generated by single-cell RNA sequencing, and cell types were clustered and named by unsupervised clustering and annotation analysis. Results: PBMCs were profiled for 6 kinds of cell types, the biological properties of T cell and monocytes were shown in a detailed manner. We noticed that monocytes could be clustered into 6 subsets, with great heterogeneity in the alteration of composition, gene profile, and signaling pathways driven by sepsis. Moreover, the expression of representative genes was high associated with septic clinical indicators in clusters of monocytes, such as NEAT1. Conclusions: Although the study was preliminary, we revealed sepsis-specific alteration of PBMCs and associated pathways. These results give a panoramic picture of PBMCs in composition, genes profiles, and pathway signatures that are driven by sepsis, which offers a unique perspective to understand disease progression or treatment in clinical practice.