4c). in tuberculosis latency, with a corresponding decrease during active disease and a return to baseline levels upon clinical remedy are features that are common to all cohorts. Furthermore, by analysing three longitudinal cohorts, we find that changes in peripheral levels of natural killer cells can inform disease progression and treatment responses, and inversely correlate with the inflammatory state of the lungs of patients with active tuberculosis. Together, our findings offer crucial insights into the underlying pathophysiology of tuberculosis latency, and identify factors that may influence contamination outcomes. Although most infections do not lead to the manifestation of clinical disease, few studies have focused on delineating the immune factors that are associated with the asymptomatic says that comprise latent tuberculosis contamination (LTBI). To broadly characterize this immune state, we used high-dimensional cytometry by time-of-flight (CyTOF), a proteomics technology that assesses the large quantity of cell subsets, protein expression and activation of signalling pathways at the single-cell resolution4 (Fig. 1a). We analysed peripheral blood mononuclear cells (PBMCs) from uninfected and latently infected adolescents (aged 13C18 years) from South Africa (Supplementary Table 1). This cohort is usually from a highly endemic area but has a lower rate of active tuberculosis (TB) than is seen in young children and adults5, indicating a well-controlled contamination. Open in a separate windows Fig. 1 | Schematic representation of the experimental design.a, Identification of immune features distinguishing uninfected and latently infected individuals from a cohort of South African adolescents. contamination (QuantiFERON converters); (2) progressed from LTBI to active TB, and (3) patients with active TB who proceeded to treatment completion; and their correlations with pulmonary pathology as measured by PETCCT imaging. ATB, active tuberculosis; EOT, end-of-treatment; UC, uninfected controls. An initial analysis (Supplementary Table 2) of 14 uninfected controls and 14 individuals with LTBI recognized four cell subsets (defined by cell-surface protein expression) with a significantly higher Mouse Monoclonal to CD133 percentage (of total live cells) in individuals with LTBI than uninfected controls (false discovery rate (FDR) of <1%). These four subsets comprised total CD16-expressing cells, natural killer (NK) cells and two closely PFI-1 related populations of CD27?CD8+ T cells that differed in their CD38 expression. By contrast, two other cell subsets, total B cells and naive B cells, were PFI-1 significantly less abundant in individuals with LTBI (Fig. 2a and Extended Data Fig. 1aCc). Comparable differences in NK cell and B cell percentages between uninfected controls and individuals with LTBI were also observed in an additional 20 individuals analysed by CyTOF, and another 32 individuals analysed by circulation cytometry (Extended Data Fig. 1d). Because latently infected individuals show no significant switch in peripheral monocyte or lymphocyte counts compared to uninfected controls6,7, changes in the percentage of a given cell type most likely reflect corresponding alterations in its large quantity. Open in a separate window Fig. Immune state of TB latency recognized in a cohort of South African adolescents.a,b, Frequencies of cell subsets were defined by surface marker (a) and effector molecule (b) expression that are present in significantly (FDR < 1% by SAM analysis) different abundances between uninfected controls and individuals with LT BI (= 14 per group) as determined PFI-1 by Citrus analysis of CyTOF results (Extended Data Figs. ?Figs.1,1, ?,2).2). c, Cytolytic responses of NK cells isolated from PBMCs of uninfected controls and individuals with LT BI (= 10 per group), quantified by calcein-release from calcein-labelled target (K562) cells upon lysis. d, Percentages of CD16+GZMBhigh cells within each lymphocyte subset in uninfected controls and individuals with LT BI (= 14 per PFI-1 group) (Extended Data Fig. 2f). e, ADCC response of total PBMCs from uninfected controls and individuals with LTBI (= 12 per group) as determined by antibody-mediated killing of CFSE-labelled target (P815) cells (Extended Data Fig. 2g). f, Frequencies of phosphorylated ribosomal protein S6 (pS6)+ cells within T cell subsets under different activation conditions in uninfected controls and individuals with LTBI (= 10 per group). g, Volcano plot of plasma protein large quantity in uninfected controls and individuals with LTBI (= 27 per group) (Supplementary Table 3). Throughout, values were derived using a MannCWhitney = 10 per group, = 0.003; Fig. 2c). Additionally, there were higher percentages of CD16+GZMBhigh cells within the compartments of the NK cells, CD8+ T cells and T cells in PBMCs from individuals with LTBI (Fig. 2d and Extended Data Fig. 2f). PBMCs from individuals with LTBI also mounted significantly higher antibody-dependent cell-mediated cytotoxicity (ADCC) responses than those from uninfected controls (= 12 per group, = 0.006; Fig. 2e and Extended Data PFI-1 Fig. 2g). ADCC allows antibodies, in addition to T cells, to contribute to.