CFP-10/ESAT-6-specific CD8 T cell phenotype is associated with mycobacterial antigen load.

<p>Phenotypic analysis of CFP-10 and ESAT-6-specific IFN-γ⁺ CD8 T cells was performed as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0094949#pone-0094949-g001" target="_blank">Figure 1</a>. Cells were analyzed prior to initiating anti-TB treatment (Pre-TB Tx), and 2 months and 6 months after initiation of treatment. (<b>A</b>) Flow cytometry data indicating Ki67 and Bcl-2 expression by IFN-γ⁺ ESAT-6-specific CD8 T cells from a TB diseased patient at two time points: prior to treatment and 6 months after initiation of treatment, corresponding to the end of the treatment period. (<b>B</b>) Representative histogram overlays indicating expression of Bcl-2, CD127 and CD95 within CFP-10/ESAT-6-specific IFN-γ⁺ CD8 T cells. Black lines indicate expression prior to treatment; grey lines indicate expression 6 months after initiation of treatment. The numbers in the upper right corner of the histograms indicate the median fluorescence intensity (MFI) at each time point (black: pre-treatment MFI; grey: 6-month TB treatment MFI). Data shown in panels A and B are gated on VIVID^l°CD3⁺CD8⁺IFN-γ⁺ cells. (<b>C</b>) Summary data comparing the expression of Ki67, Bcl-2, CD127 and CD95 on CFP-10/ESAT-6-specific IFN-γ⁺ CD8 T cells from the same individual at two time points: prior to treatment (Pre-TB Tx) and at the end of the 6-month treatment period (6 mo. TB Tx). Data are shown from 7 individuals who maintained positive CFP-10/ESAT-6-specific CD8 T cell responses throughout the 6-month duration of treatment. Differences between time points were assessed using the Wilcoxon matched pairs test. § indicates p values that did not retain statistical significance after applying the Bonferroni correction for multiple comparisons. The proportion of CFP-10/ESAT-6-specific IFN-γ⁺ CD8 T cells that express Ki67 (<b>D</b>), CD95 (<b>E</b>), Bcl-2 (<b>F</b>), and CD127 (<b>G</b>) are shown for individuals with LTBI (n = 6), and TB diseased patients prior to treatment (n = 13; Pre-TB Tx), and 2 months (n = 10; 2 mo. TB Tx) and 6 months (n = 8; 6 mo. TB Tx) following initiation of treatment. Differences in panels D-G were first assessed using a Kruskal-Wallis test, followed by a Dunn's post-test to correct for multiple comparisons; § indicates p values that did not remain significant following correction with the Dunn's post-test.