Fig. 2

MC38 tumor growth and systemic immune response activation after immunotherapy (Exp. A) or chemoimmunotherapy (Exp. B); a, b Schemes of treatment; c, d Median of MC38 tumor growth after therapies. As a control of LV preparations, the PBS containing aggregates of polyethylene glycol (PEG) with cell debris remaining in the culture supernatant collected from untransfected Lenti-X packaging cell line was applied. The differences between groups were estimated using Friedman test. The box graphs present the median of tumor volume, calculated on the 36th day for the Exp. A and on the 43rd day for the Exp. B; e MC38 tumor growth inhibition (TGI) for Exp. A was calculated on the 36th day in relation to untreated group and for Exp. B - on 43rd day in relation to CY treated group; f, g Spleen cells activity in Exp. A (f) and Exp. B (g). Splenocytes obtained from the treated mice on the 36th day of experiments were restimulated in vitro in the presence of MC38 cells for 5 days. The ability of restimulated splenocytes to produce IFN-γ, IL-10 and IL-4 was determined by measurement of the cytokine concentrations in supernatants collected after 5 days of restimulation using ELISA. The presented data show the cytotoxic activity of restimulated cells towards MC38 tumor (the specific killing of DiOC18 labelled MC38 tumor cells was assessed by PI incorporation flow cytometry measurement) and the percentage of CD107a positive cells among cytotoxic CD8⁺ and CD49b⁺ cells. To calculate the mean ± SD at least 5 mice per group were analyzed in one of the two independent experiments. The differences between the groups were estimated using nonparametric Kruskal-Wallis test followed by Dunn’s multi comparison test (* p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001)