Fig. 1: IFN-γ competence of BALB/c mice rises with age and reduces resistance to Th2-controlled H. polygyrus infection.

a Representative contour plots depicting PMA/ionomycin-induced IFN-γ expression by CD4+ and CD4− cells derived from the spleen and small intestinal lamina propria (siLP) of naïve BALB/c mice at the age of 1.5, 3 and 16 months. Graphs depict correlation between the percentage of IFN-γ+ cells detected in CD4+ and CD4− cells and mouse age. Data from multiple independent experiments are pooled (n = 23–24 mice). b Frequencies of T-bet expressing cells in CD4+ GATA-3+ cells in blood at day 7 and day 14 post infection with H. polygyrus. Data from two independent experiments are pooled (n adult = 11–12; mature = 7–8 mice). c Representative flow cytometry plots depicting T-bet vs. GATA-3 expression in siLP-derived CD4+ FoxP3− cells at day 28 post H. polygyrus infection. Graphs report the frequencies of Th2/1, Th2 and Th1 cells in CD4+ FoxP3− siLP cells. Data from two independent experiments are reported (n adult naïve = 4; mature naïve = 5; infected adult = 12; infected mature = 7 mice). d Kinetics of fecal egg counts per gram feces over the course of infection in adult and mature mice. Data derive from one out of two experiments with similar results (n adult = 6; mature = 4 mice) and are shown as mean ± SD. e Adult worm counts at day 28 post infection. Data from two independent experiments are pooled (n adult = 12; mature = 7 mice). f Average number of eggs produced by individual female worms (typically eight worms per mouse, minimum 3) isolated from each mouse at day 28 post infection and cultured for 24 h. Data from two independent experiments are pooled (n adult = 8; mature = 6 mice; note that expulsion was completed in 4 adult and 2 mature mice). g Scatter graphs depict the correlation between the percentage of IFN-γ+ in siLP CD4+ T cells determined after PMA/ionomycin stimulation at day 28 post infection, and the mean egg counts produced by worms from the same mouse. Data derive from four experiments (n = 16). Bars in b, c, e, and f report the mean, circles represent individual mice. Statistical analysis was performed using Pearson correlation or nonparametric Spearman correlation analysis depending on the normality tests in a and g; unpaired t test or Mann–Whitney test in b, d and f; one-way ANOVA with Tukey’s multiple comparisons test or Kruskal–Wallis test with Dunn’s multiple comparisons test in c. *p ≤ 0.05, **p ≤ 0.01, ****p ≤ 0.0001.