Fig. 6.

The addition of a TIGIT inhibitor to RT enhances DC numbers and function in MC38 tumor-bearing mice. Mice were inoculated with MC38 cells on day 0. On day 10, mice were given either isotype IgG, anti-TIGIT therapy, RT, or RT plus anti-TIGIT therapy. Tumors and TdLNs were excised on day 10. a. CD155 expression in CD11c + DCs purified from MC38 TdLNs (red lines), non-draining LNs (green lines), and healthy mouse LNs (purple lines). Representative flow cytometry histogram (left) and quantification of CD155 mean fluorescent intensity in DCs (right). b. Representative flow cytometry contour plots of CD155 expression on DCs after RT in tumors and TdLNs (n = 5); Quantitation of CD155 MFI on DCs is shown on the right. c. Bar graphs show the DC density in tumor tissues as measured by flow cytometry. (d-e). Intracellular IL-10 and IL-12 (interleukin 10 and 12) levels on gated CD11c + DCs from tumor tissues. f. Bar graphs show the DC density in TdLNs as measured by flow cytometry. (g-h). Intracellular IL-10 and IL-12 levels on gated CD11c + DCs from TdLNs. For intracellular cytokine staining, cells were stimulated with Cell Activation Cocktail (with Brefeldin A) (1:500) for 4–5 h before being harvested for cell surface staining, after which cells were fixed and permeabilized and stained with IL-10, and IL-12. Results are shown as the means ± SEM (standard errors of the mean) for one experiment (n = 5). *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001. DCs, dendritic cells; IgG, immunoglobulin G; LNs, lymph nodes; NS, not statistically significant; RT, radiotherapy; TdLNs, tumor draining lymph nodes; TIGIT, T cell immunoreceptor with immunoglobulin and ITIM (immunoreceptor tyrosine-based inhibitory motif) domains