Fig. 5: IFN-γ and IL-17A, independent of IL-10, confer IsdBCAF01 vaccine protection against SA in SA-exposed mice.

a Serum (150 µl) collected 14dpv of SA-exposed vaccinated WT mice was transferred i.v. into naive mice. The recipient mice were challenged 20 h after with SA (n = 5 per group). b SA-exposed muMT^- mice were vaccinated i.p. with Alum (n = 4), AIsdB (n = 4), CAF01 (n = 7) or CAF01IsdB (n = 6), then challenged with SA 14 dpv. c, d SA-exposed WT mice were vaccinated i.p. with PBS (n = 7 in d), Alum (n = 8 in c and 10 in d), AIsdB (n = 10 in c and 9 in (d), CAF01(n = 10 in (c, d) or CAF01IsdB (n = 11 in c and 13 in d). 14 dpv, splenic CD3⁺ T cells or CD4⁺ T cells were transferred i.v. into naïve WT mice. After 20 h, the recipient mice were challenged with SA challenged. e SA-exposed WT mice were vaccinated i.p. with Alum, AIsdB, CAF01 or CAF01IsdB. 14 dpv, splenocytes (1.5 × 10⁶, n = 5) were isolated and restimulated with IsdB antigen (10 µg/ml) for 48 h, followed by intracellular cytokine analysis by flow cytometry. f SA-exposed WT mice were vaccinated i.p. with PBS (n = 9), CAF01 (n = 10) or CAF01IsdB (n = 8). After 30 dpv, the mice were treated with an isotype IgG1 control or anti-IFN-γ (aIFN-γ) Mab, one day before and on the day of SA challenge. g SA-exposed WT or IL-17^-/- mice were vaccinated i.p. with Alum (n = 5), AIsdB (n = 5), CAF01 (n = 3 or 7) or CAF01IsdB (n = 3 or 9), then SA challenged 14 dpv. Data were from one to two independent experiments with each data point representing one mouse. The data are presented as mean ± SD of biological replicates. The data in (a, b, e, g) were analyzed by one-way ANOVA with Tukey’s post-hoc test, while the data in (c, d, f) by Kruskal-Wallis non-parametric one-way ANOVA test *p < 0.05, **p < 0.01, ****p < 0.001, ****p < 0.0001. ns, non-significant. dpv, days post-last vaccination. SA, Staphylococcus aureus. WT-wild-type Source data are provided as Source Data File.