The mice with s.c. and i.c. tumors were treated as depicted in Figure 2A. Three days after the last dose of viral injection, tissues were collected from the mice (4-5 mice/group) for immunological analysis. A-D, The leukocytes from the blood (A and B) and brain hemispheres with tumor implantation (C and D) were analyzed with flow cytometry to assess the frequency of T cells (CD3+), cytotoxic T cells (CD3+ CD8+), and T helper cells (CD3+ CD4+) (A and C); and the frequency (B) and number (D) of effector T cells. A and C, Left panel: Representative flow cytometry plots; the numbers are the frequency of the gated cell populations. Right panel: quantification of the cell populations in left panel. E, Splenocytes and cells from inguinal lymph nodes (tumor-draining lymph node of the s.c. tumor) were co-cultured with B16F10 Red-FLuc-3 cells with or without the infection of the indicated viruses. The amount of IFNγ secreted into the medium was assessed with ELISA forty hours later. D24-RGD: Delta-24-RGD; D24-RGDOX: Delta-24-RGDOX. Teff: effector T cells. Values represent means ± standard deviations (n = 3). NS: not significant (P ≥ 0.05); *P < 0.05, 2-tailed Student t-test.