Functional effects of CD8_CXCR5+ICOS+T cells. Cell Trace–labeled purified B cells from lymphoma tissues were activated by anti-BCR and CpG and cocultured with autologous sorted T cells in presence of PHA and IL-2 for 5 days (n = 3). (A) Proliferation of B cells evaluated by DI in each condition. (B) Representative dot plots and histograms for percentages of IgD⁺CD38⁻, IgD⁺CD38⁺, and IgD⁻CD38^+/− cells among viable B cells (top) and proliferation rate of IgD⁻CD38^+/− B cells (bottom) after 5 days of coculture in each condition. (C) IgG production measured in supernatant at day 5 by ELISA. A 1-way ANOVA statistic test was done.