Fig. 6.

HNSCC-secreted galanin modulates T cell activation. Activation of CD3⁺ (A) and CD8⁺ (B) cells (CD3⁺/CD69⁺ and CD8⁺/CD69⁺, respectively) after treatment of PBMCs with CM from UM-SCC-(1 and 22B) with siRNA-mediated silencing of galanin. UM-SCC1-secreted galanin did not affect activation of CD3⁺ cells, but increased activation of CD8⁺ cells. UM-SCC-22B-secreted galanin reduced activation of both CD3⁺ and CD8⁺ cells. A complementary experimental approach of antibody-mediated depletion indicates that tumor cell-secreted galanin significantly inhibited activation of both CD3⁺ (C) and CD8⁺ (D) cells. In all graphs, each color/shape represents an independent experiment with three replicates in each experiment. Different colors/shapes between the same group represent independent experiments. Two independent experiments with PBMCs of donor #1 and a third independent experiment with PBMCs of donor #2 were performed. Each independent experiment encompassed three replicates. * p < 0.05 and **** p < 0.0001