Circulating HLA-DR+CD4+ effector memory T cells resistant to CCR5 and PD-L1 mediated suppression compromise regulatory T cell function in tuberculosis
Fig 3
Teff cells from PTB patients are resistant to suppression whilst their Treg cells preserve suppressive potential.
A diagrammatic representation of a criss-cross assay (A). A fixed number of CFSE labelled CD25- effector cells isolated by magnetic beads were cultured with different ratios of either autologous or heterologous CD25+ suppressors also isolated by magnetic beads. Cells were activated with anti-CD3/anti-CD28 activator beads at a Teff cell:bead ratio of 2:1 for a period of 4 days. After this CFSE dilution was measured by flow cytometry. Proliferation of IGRA-ve, PTB and ATT Teff cells in absence of suppressors was compared (B). Percentage suppression was calculated as described in Materials and Methods and is compared between autologous and heterologous criss-cross cultures between Teff and Treg cells from different clinical categories (C). Cells from 6 IGRA-ve, 8 PTB and 4 ATT donors were used to set up autologous or heterologous criss-cross assays. Data shown in (B) is mean + SEM and in (C) is median and range from multiple donors. P value was determined by non-parametric One-Way ANOVA Kruskal–Wallis test and Dunn’s multiple comparisons test. ***p < 0.001, **p < 0.01, *p < 0.05, ns- not significant.