Fig. 3. H1_Y98F-VLP promotes enhanced germinal center selection.

Mice were immunized with 0.5 µg H1_WT- or H1_Y98F-VLP in the right hind limb footpad and popliteal lymph nodes (pLN) were harvested at indicated time points. The mean frequency (±SEM) of (a) CD19⁺Fas⁺GL7⁺ GC B cells and (b) CD3⁺CD4⁺CXCR5⁺PD-1⁺ T_FH cells was determined by flow cytometry. Representative plots showing GC B cell and T_FH gating are shown on the right. To identify H1-specific GC B cells, freshly isolated cells were incubated with 1 µg/ml H1_Y98F-VLP (30 min, 4 °C) and cognate GC B cells were detected following staining with anti-H1 FITC. c Representative plots and d mean frequency (±SEM) of HA⁺ cells among GC B cells. Data are pooled from three independent experiments, n = 7–13/group at each time point. Statistical significance between groups at each time point was determined by Mann–Whitney test (*p < 0.033).