Single-cell RNA Sequencing In Pediatric Sepsis: γδ T Cell Exhibits A Differentiation To γδT17 Subtype Along With Significantly Enhanced Cell Communication With Neutrophils.

Abnormal immune responses are common clinical features in septic patients. γδ T cells, as innate immune cells, play an important role in host defense, immune surveillance and homeostasis. However, the immune characteristics of γδ T cells in pediatric sepsis remains remain poorly understood. In this study, we analyzed single-cell RNA high-throughput sequencing data of peripheral blood mononuclear cells (PBMCs) from pediatric septic patients. It demonstrates that γδ T cells exhibit a proinflammatory state with heightened immune responsiveness to pathogens in pediatric sepsis, as confirmed by the results of flow cytometric analysis showing elevated Th1 cytokines secretion, increased activation, and a propensity to differentiate into IL-17-producing (γδT17) cells during disease progression. Pseudotime analysis identified seven key genes potentially regulating the differentiation of γδ T cells to γδT17 subtype. Furthermore, cell-cell communication analysis revealed enhanced RETN-CAP1 binding between neutrophils and γδ T cells in pediatric sepsis, suggesting that neutrophil-derived resistin may promote γδ T cell differentiation into the γδT17 subtype via CAP1 receptor binding. In conclusion, this study provides a single-cell study that analyzed the immune status of γδ T cells in pediatric sepsis, highlighting their pivotal roles in pathogen response, inflammation propagation, and immune regulation. The observed differentiation toward the γδT17 subtype may facilitate neutrophil recruitment in this life-threatening condition. Elucidating the molecular mechanisms of γδ T cells in pediatric sepsis could offer a new theoretical basis for novel therapeutics.