<p>Pools of <i>Francisella</i> MHC-II peptides elicit time-dependent, specific and CD4⁺ T cell-mediated IFN-γ response in immune splenocytes.</p>

Lymphocytes were isolated from LVS immunized (immune) or age-matched control (control) mice. Data of individual assayed wells per condition and mean values are shown. Responses were assessed for significant difference using a two-tailed t-test.

(E) IFN-γ and (F) TNF-α concentrations were determined by ELISA in cell culture supernatants of 8 × 10⁵ LVS-immune splenocytes (3 weeks p.i.) after 48 h of PPs stimulation. Data of 3 biological replicates and mean values are shown. PPs with significant response against control without peptides were detected with one-way ANOVA followed by Dunnett’s post hoc test.

PPs representing a subset of 15 peptides (Table B in <a href="plospathogens.org/article/info:doi/10.1371/journal.ppat.1014597#ppat.1014597.s002" target="_blank">S1 Appendix</a>) were used for all assays with 5 µM final concentration of each peptide. Ova II peptide (5 µM) was used as a negative control in some experiments. Asterisks indicate p-values (**p < 0.01, ***p < 0.001, ****p < 0.0001, ns for p ≥ 0.05).

Data are results of one experiment (A, B, C) or representative results of two biological replicates (D).</p>