Fig. 3: CD70 on human cDC1 promotes the CTL response to CD4⁺ T-cell help.

Sorted cDC1 were incubated with CD70 blocking antibody (CLB-2F2⁵⁴) or isotype control and entered in the priming system with MART-1_15-40 long peptide in presence of activated (a) CD4⁺ T-cells. a Schematic depiction of the tumor antigen-specific CTL priming system in the presence of CD70 blockade. b Light microscopic images depicting CTL priming system at day 7 under indicated conditions. Images are representative of three independent experiments. c Flow cytometry plots depicting MART-1-specific CD8⁺ T-cell proliferation based on CTV dilution and CTL differentiation based on intracellular Granzyme B staining in response to antigen presented by cDC1. d Quantification of the % MART-1_26-35/HLA-A2-specific (tetramer⁺) cells within CTV⁻negative (⁻) CD8⁺ T-cells (left) and the number (#) of live MART-1-specific CTV⁻CD8⁺ T-cells (right). e Quantification of the % Granzyme B⁺ cells among CD8⁺ T-cells (left) and MFI of Granzyme B expressed by CD8⁺ T-cells (right). d, e share the same legends. Data are pooled from three independent experiments (n = 3) in (d, e), each with technical duplicates. p < 0.05*, p < 0.01**, p < 0.001*** (One way ANOVA). Data are shown as means ± SEM in (d, e).