Figure 2.
Enhanced Immune Responses of CTLs from PD-L1-KO Tumor
(A) Proliferating activity of MC38 or MC38-PD-L1-KO cells in vitro by WST-1 assay. Data are pooled from three independent experiments, and the values represent mean ± SD.
(B) C57BL/6J (left) or Rag1−/− (right) mice were injected with 5 × 105 MC38 or MC38-PD-L1-KO cells, subcutaneously (s.c.). Tumor growth was monitored at indicated time points by measuring three perpendicular diameters. MC38 or MC38-PD-L1-KO in C57BL/6J mice n = 20 and 21/group, respectively, in Rag1−/− mice, n = 6/group. Data are pooled from four and two independent experiments, and the values represent mean ± SEM.
(C) C57BL/6J mice were injected with 5 x 105 MC38 cells or MC38-PD-L1-KO cells s.c. and then treated with anti-PD-1 and anti-CTLA-4 on day 7, 10, and 13. Tumor growth was monitored at indicated time points by measuring three perpendicular diameters. (n = 17/group). Data are pooled from six independent experiments, and the values represent mean ± SEM.
(D) The frequency of immune cells in tumor sites was analyzed at day 15 after tumor inoculation by flow cytometric analysis. The values represent mean ± SD (n = 4/group). Closed and open bar indicated MC38 and MC38-PD-L1-KO tumor-bearing mice, respectively; ns indicates not significant.
(E) Tumor antigen-specific T cell response in ICB-treated MC38 or MC38-PD-L1-KO tumor-bearing mice. Frequency of MutAdpgk tetramer+ in CD8+ T cells was plotted. Data are pooled from four independent experiments; n = 10/group. Data were analyzed by unpaired Student's t test, ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001.