Fig 1: B cells from aged donor mice have no defects in class-switch recombination, entering the GC response and plasmablast differentiation. (A) Schematic diagram of adoptive transfer experiments to compare the response of B cells from young (6–12 wo) and aged (>90 wo) mice in young recipient mice postimmunization with NP-KLH in Alum. Draining iLNs were taken at indicated times postimmunization for downstream analyses. (B) Graphs depicting the percentage and number of donor NP+B220+CD19+ cells out of live cells in recipient iLNs at different time points posttransfer and immunization. (C–F) Representative flow-cytometric plots showing gating strategies for donor-derived IgG1+IgD− B cells (C) and CD38−GL7+ GC B cells (E) from 6-wo or 91-wo donor mice at different time points posttransfer and immunization. Numbers adjacent to gates indicate percentage of donor NP+B220+CD19+ cells. Graphs depicting the percentage and number of donor NP+IgG1+ cells (D) and donor NP+CD38−CD95+GL7+ cells (F) in recipient iLNs at different time points posttransfer and immunization. Statistics were calculated using two-way ANOVA with Sidak’s multiple comparisons test. (G) Representative flow-cytometric plots showing gating strategies for donor-derived CD138+B220lo cells from 6-wo or 91-wo donor mice at day 6 posttransfer and immunization. Numbers adjacent to gates indicate percentage of donor cells. (H) Graphs depicting the percentage and number of donor CD138+B220lo cells in recipient iLNs at day 6 posttransfer and immunization. Bar height corresponds to the mean, error bars indicate SD, and each symbol represents values from individual recipient mice. Statistics were calculated using unpaired Mann–Whitney U test. Data are representative of two independent repeat experiments. wo, wk old.