Fig. 4: ZIKV infection elicits polyfunctional CD8⁺ effector memory T cell responses.

A Experimental timeline for intracellular cytokine staining (ICS). Female BALB/c mice (n = 5/ group) were infected i.v. with 200PFU ZIKV_PRVABC59 or left uninfected. At day 35 post-infection, splenocytes were harvested and stimulated with mapped immunodominant ZIKV peptides for cytokine profiling. B Heatmap depicting the frequency of CD44^highCD62L^-CD8⁺ effector memory (EM) T cells in ZIKV infected versus uninfected mice. Spider plots showing the frequency of (C) IFN-γ, (D) TNF-α and (E) IL-2 producing CD8⁺ T_EM cells following peptide stimulation. Polyfunctionality analysis of CD8⁺ T_EM cells showing dual cytokine expression (F) IFN-γ⁺ IL-2⁺, (G) IFN-γ⁺ TNF-α⁺ and (H) IFN-γ⁺ TNF-α⁺ IL-2⁺. Data are expressed as mean ± SEM. Statistical significance between groups was determined by Mann–Whitney U tests. To account for multiple testing, p-values were adjusted using the Benjamini–Hochberg false discovery rate (FDR) method *P < 0.05, **P < 0.01.