Fig. 2.

ELISpot assay shows that combination immunotherapy skews systemic antitumor immunity toward Th1 polarization. (A) Splenocytes harvested from GVAX + agonist anti-OX40 treated glioma-bearing mice expressed significantly higher levels of Th1 cytokines IFN-γ, TNF-α, and IL-2 and granzyme B after combination immunotherapy compared with splenocytes harvested from either PBS or monotherapy-treated mice. Th2 cytokine (IL-13 and IL-10) was less impacted by treatment—GVAX monotherapy increased IL-13 expression levels compared with PBS treatment, and combination immunotherapy increased IL-10 expression from splenocytes, but with less significance. (B) The positive fold change of splenocyte expression of IFN-γ was higher than it was for IL-10. (C) The ratio between the fold change from IFN-γ vs the fold change for IL-10 was highly positive after any immunotherapy and highest after combination GVAX + agonist anti-OX40 treatment in glioma-bearing mice. Splenocytes were examined from 3 animals per group. (***P < 0.0005, **P < 0.005, *P < 0.05; absence of an asterisk denotes not significant comparison.)