Inhibitory and suppressed T-cell populations in tonsils.

<p>CD4(+) and CD8(+) T-cells purified from tonsillar samples were subjected to fluorescence assisted immune phenotyping for the determination of inhibitory T-cell subgroups. All shown measurements were carried out on the mixed CD4(+)CD8(+) preparations. <b>(A)</b> The incidence of regulatory T-cells (Tregs) was determined by triple CD4/CD25/FoxP3 staining and plotted as percentage of Tregs in all T-cells both for tonsillar and blood samples. For statistical analysis, see suppl.<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0183214#pone.0183214.s001" target="_blank">S1 Table</a>. <b>(B)</b> The fraction of PD-1 expressing T-cells was determined by flow cytometric determination of PD-1 cell surface staining and plotted as percentage of PD-1(+) cells in CD4(+) lymphocytes (CT-ton vs. PTA-abs.ton p = 0.026). <b>(C)</b> The surface expression of CTLA-4 on tonsillar T-cells was determined by flow cytometry and plotted as percentage of CTLA4(+) in all T-cells. * indicates comparisons that met an unadjusted p≤0.05 (explorative significance level). CT = chronic tonsillitis; PTA = peritonsillar abscess; HY = tonsillar hyperplasia; ton = tonsil; abs = abscess.