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. Author manuscript; available in PMC: 2015 Dec 18.
Published in final edited form as: Immunity. 2014 Dec 8;41(6):1001–1012. doi: 10.1016/j.immuni.2014.12.011

Figure 3. Effect of peptide stimulation on caspase-8 activity and localization in HIV-specific CD8+ T cells.

Figure 3

(A) Representative data showing modulation in MFI of caspase-8 activity following 1h peptide stimulation (1 ug/mL) in KK10-specific CD8+ T cell responses from an HLA-B*2705 EC and CP. Filled plot (gray) represents caspase-8 MFI in the absence of KK10 peptide and dashed line represents caspase-8 MFI in the presence of KK10 peptide. (B) Summary data of change in caspase-8 activity following peptide stimulation in ECs (n = 6), VC (n = 2) and CPs (n = 8). Filled symbols represent HLA-B*2705 KK10-specific responses and open symbols represent HLA-B*5701 KF11-specific responses. Statistical comparisons were made using the Wilcoxon matched pairs test. (C) Representative plots of Imagestream analysis of KK10 Tetramer+ CD8+ T cells from an HLA-B*2705 EC and CP in the presence and absence of KK10 peptide (1 μg/mL). The Imagestream plots depict total cellular caspase-8 activity on the x-axis (Caspase-8 Bright Detail Intensity; Cytoplasmic, yellow) and caspase-8 activity localized in a circular ring located around the edge of the cell on the y-axis (Caspase-8 Bright Detail Intensity – Erode; Non-cytoplasmic, green). Representative images corresponding to non-cytoplasmic and cytoplasmic caspase-8 cells are shown in the lower panels. (D) Representative histograms of Imagestream analysis of non-cytoplasmic caspase-8 KK10 Tetramer+ CD8+ T cells. The histograms depict the maximum pixels of caspase-8 activity on the x-axis, which successfully differentiates caspase-8+ KK10 Tetramer+ CD8+ T cells with membrane-associated caspase-8 activity from those with negative caspase-8 activity. Representative images of membrane-associated caspase-8 positive cells are shown in the lower panels. (E) Summary of percentage of membrane-associated caspase-8 and cytosolic caspase-8 positive KK10-specific CD8+ T cells within a group of ECs (n = 4) and CPs (n = 4). Statistical analyses were carried out using the paired t test (intra-patient group comparison, −/+ peptide) and the Mann-Whitney test (inter-patient group comparison). See also Supplemental Figure 3.