γδ T cell profiling in a cohort of preterm infants reveals elevated frequencies of <i>CD83</i>+ γδ T cells in sepsis
Ximena León-Lara, Alina Suzann Fichtner, Maike Willers, Tao Yang, K. Schaper, Lennart Riemann, Jennifer Schöning, Anna L. Harms, Vicente Almeida, Anja Schimrock, Anika Janssen, Laura Ospina-Quintero, Constantin von Kaisenberg, Reinhold Förster, Matthias Eberl, Manuela Richter, Sabine Pirr, Dorothee Viemann, Sarina Ravens
Abstract
Preterm infants are at high risk of developing neonatal sepsis. γδ T cells are thought to be an important set of effector cells in neonates. Here, γδ T cells were investigated in a longitudinal cohort of preterm neonates using next-generation sequencing, flow cytometry, and functional assays. During the first year of life, the Vγ9Vδ2 T cell subset showed dynamic phenotypic changes and elevated levels of fetal-derived Vγ9Vδ2 T cells were evident in infants with sepsis. Single-cell transcriptomics identified HLA-DRhiCD83+ γδ T cells in neonatal sepsis, which expressed genes related to antigen presentation. In vitro assays showed that CD83 was expressed on activated Vγ9Vδ2 T cells in preterm and term neonates, but not in adults. In contrast, activation of adult Vγ9Vδ2 T cells enhanced CD86 expression, which was presumably the key receptor to induce CD4 T cell proliferation. Together, we provide a map of the maturation of γδ T cells after preterm birth and highlight their phenotypic diversity in infections.