FIG 6.

Pretreatment with IL-2 Ab Cx perturbs proliferation of activated CD4⁺ Teff cells. WT mice (n = 5 per group) were infected s.c. with 10⁶ PFU CHIKV-SGP011 after treatment with PBS, IL-2 only, JES6-1 only, or IL-2 Ab Cx. (A) Representative scatterplot of CD25 expression and BrdU staining of Teff cells. BrdU was injected i.p. into mice daily for 2 days before euthanasia to detect proliferating cells. Cells isolated from draining pLN at 6 dpi were isolated for flow cytometry and gated on CD4⁺ Teff cells for analysis. The bar chart shows the average number of BrdU⁺ CD25⁺ Teff cells per pLN. (B) Histogram showing Ki-67 expression on CD4⁺ Teff cells (left) and bar charts showing mean fluorescence intensity (MFI) of Ki-67 on Teff cells (middle) and average percentage of Ki-67⁺ Teff cells (right). Statistical analysis was done using one-way ANOVA across all CHIKV-infected groups, followed by Dunnett's posttest comparing to the PBS-CHIKV group. Data are means and SD from three independent experiments. *, P = 0.0324 (IL-2 Ab Cx percentage BrdU⁺ Teff cells); ***, P < 0.0001 (IL-2 Ab Cx Ki-67 MFI and IL-2 Ab Cx percentage Ki-67⁺ Teff cells).