CD8<sup>+</sup>T-APCs activate anti-tumor CD8 T cells of the same antigen specificity. Ronny Uzana Galit Eisenberg Sharon Merims Shoshana Frankenburg Aviad Pato Eitan Yefenof Roni Engelstein Tamar Peretz Arthur Machlenkin Michal Lotem 10.1371/journal.pone.0118244.g001 https://plos.figshare.com/articles/figure/_CD8_T_APCs_activate_anti_tumor_CD8_T_cells_of_the_same_antigen_specificity_/1306502 <p><b>(A-C)</b> Cytokine production by effector CTLs in response to activation by T-APCs. <b>(A)</b> DiIC<sub>18</sub>-labeled CD8<sup>+</sup>T-APCs (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118244#sec002" target="_blank">materials and methods</a>) were incubated for 6 hours with surface-biotinylated effector CTLs. Cytokine-producing effector CTLs were defined based on intracellular IFN-γ or TNF-α staining of CD8<sup>+</sup>streptavidin<sup>+</sup> lymphocytes. Numbers in upper right quadrants indicate the percentage of IFN-γ <sup>+</sup> (upper panel) or TNF-α <sup>+</sup> (lower panel) effector CTLs. Labels indicate cells used as targets for CTLs: CTLs co-cultured with 624<i>mel</i> melanoma cells are designated T-APC; CTLs co-cultured with irrelevant M171 melanoma cells are designated non T-APC. <b>(B)</b> Confocal images of cytokine-producing effector CTLs. Calcein AM labeled CD8<sup>+</sup>T-APCs (<i>green</i>, upper panel) or non T-APCs (<i>green</i>, lower panel) were co-cultured for 6 hours with streptavidin-allophycocyanin-stained effector CTLs (<i>red</i>). Intracellular TNF-α production (<i>blue</i>) by effector CTLs is shown. Scale bars are 10 μm (upper panel) and 20 μm (lower panel). <b>(C)</b> Time period that CD8<sup>+</sup>T-APCs activate effector CTLs. Effector CTLs were co-cultured with CD8<sup>+</sup>T-APCs either immediately or 6, 24 and 48 hours after CD8<sup>+</sup>T-APC purification. Data are mean ± SE (n = 3 replicates/group) percentage of IFN-γ <sup>+</sup> effector CTLs, gated on CD8<sup>+</sup> T cells. <b>(D)</b> CD8<sup>+</sup>T-APCs trigger degranulation of effector CTLs. CD8<sup>+</sup>T-APCs were generated as described above (1A) and co-cultured with effector CTLs. Cytolytic activity of T cells was measured by detection of surface CD107A on CD8<sup>+</sup>streptavidin<sup>+</sup> effector CTLs. Number in upper right quadrants indicates the percentage of CD107A<sup>+</sup> streptavidin<sup>+</sup> effector CTLs. Data are representative of at least three independent experiments.</p> 2015-02-11 03:45:33 trogocytosi ctl tcr Tumor Membrane Transfer Trogocytosis t cells Human T Cell Crosstalk fraternal T cells effector apc