Broad systemic T cell immunity to

Introduction: T cell mediated immunity (T-CMI) is an important component of effective host immunity against intracellular pathogens such as Methods: Here, peripheral blood mononuclear cells from eighteen healthy volunteers with no history of typhoid fever vaccination or infection were co-cultured with autologous B-lymphoblastoid cell lines (B-LCL) previously infected with wt ST as antigen presenting cells. Non-infected B-LCL (NI) were used as controls. After 18 h or 40 h of stimulation, cells were stained with a 52-parameter mass cytometry antibody panel and analyzed using manual gating, dimensionality reduction and unsupervised clustering approaches. We studied conventional CD4 Results: All studied cell subsets showed significant (p<0.01) baseline responsiveness to ST-infected target cells when compared to NI target cells. Most functional responses were observed in activation, homing, and cytotoxicity markers across all conventional and non-conventional T cell subsets, defining in great depth the characteristics of baseline T-CMI to S. Typhi. Discussion: This high-dimensional approach showed a complex interaction between distinct cell subsets with multifunctional properties and extended previous insights into the baseline T-CMI to