Figure 1.

Vaccine-induced antigen-specific Th1 significantly reduces the rate of or completely inhibits tumor growth via secretion of IFN-γ. (A) Tumor growth rate (mm³/day), as box and whisker plots with Tukey outliers, in adjuvant only (n=131) or class II epitope immunized (n=172) mice (MMC or M6 implanted); ****p<0.0001. (B) Mean tumor volume (mm³±SEM) from mice immunized with adjuvant only (control) or an IGF-IR epitope vaccine and treated with a depletion or isotype control antibody as indicated; ****p<0.0001. (C) Ratio of Tbet⁺ to GATA3⁺CD4⁺ T cells (±SEM); adjuvant (control) or IGF-IR epitope vaccine; ****p<0.0001. (D) Mean tumor volume (mm³±SEM) from mice immunized with adjuvant only (control) or an IGF-IR epitope vaccine and treated with a neutralizing or isotype control antibody as indicated; ****p<0.0001. Mean percent positive cells (±SEM) and corresponding representative IHC for (E, F) PCNA or (G, H) TUNEL for adjuvant alone (control) or IGF-IR epitope vaccine treated with isotype control Ig (IgG) or anti-IFN-γ; n=3–6 mice/group; *p<0.05, **p<0.01. IFN-γ, interferon gamma; IL, interleukin; ns, not significant; Th1, T-helper 1; IgG, immunoglobulin G; DAPI, diamidino-2-phenylindole; IHC, immunohistochemistry; PCNA, proliferating cell nuclear antigen; TUNEL, terminal deoxynucleotidyl transferase dUTP nick end labeling.