Fig. 7

The IFN-γ pathway is required for IgG2c antibody class switching. a–d WT mice and Ifngr1^−/− mice were infected by ZIKV with anti-IFNAR1 blocking antibody at one day prior to infection. Splenocytes were collected for measurement of Tfh and GC B cell responses on 7 dpi and antibody-producing B-cell responses on 14 dpi; sera were collected on 14 dpi for assessment of antibody responses (n = 3–5 for each group). a Representative flow cytometry plots of CXCR5^highPD-1^high cells and CXCR5^mediumPD-1^medium cells in CD4⁺CD44^highCD62L^low cells were presented as Tfh cells and pre-Tfh cells (left panel); bar graphs summarized the percentages and numbers of cells in each group. b Representative flow cytometry plots of FAS⁺GL7⁺ cells in B220⁺ B cells were presented as GC B cells (left panel); bar graphs summarized the percentages and numbers of GC B cells in each group (right panel). c Representative flow cytometry plots of IgM, IgG1, IgG2b, and IgG2c staining of IgD^low B cells (left panel); bar graphs summarized the percentages and numbers of cells (right panel). d The concentrations of ZIKV envelope specific IgM, IgA, total IgG, IgG1, IgG2b, IgG2c, and IgG3 antibodies in sera were determined by ELISA. The summary data were presented as mean ± SEM. Statistical differences were determined by Student’s t test and p values were indicated by *p < 0.05, or **p < 0.01, or ***p < 0.001. Data shown represent two (a–d) independent experiments. Source data are provided as a Source Data file