Extended Data Figure 3: EBI2-deficient T cells support reduced plasma cell and germinal centre response.

a, Frequency and number of CXCR5⁺PD-1^hi CD4⁺ control (WT) and EBI2 KO OTII T cells in spleens of day 3 Listeria-OVA immunized transfer recipients. b, PD-1 and CXCR5 flow cytometric analysis of control (Het) and EBI2 KO polyclonal CD4 T cells co-transferred to OTII recipients, 8 days after immunization with unconjugated SRBCs. c, Summary of data of the type in b shown as CXCR5⁺PD-1^hi cell frequency and number. d, Flow cytometric analysis for the germinal centre markers FAS and GL7 on endogenous B cells in OTII TCR transgenic mice that received no cells, control (HET) CD4 T cells or EBI2 KO CD4 T cells, or in WT B6 control mice, 12 days after immunization with unconjugated SRBCs. e, Summary of data from d shown as number of FAS⁺GL7⁺ germinal centre B cells. f, Flow cytometric analysis for CD138^hi B220^lo plasma cells (top) and intracellular IgM and IgG1 staining of these cells (bottom) in mice of the type in d. g, Summary of data from f shown as number of cells. h, Serum anti-SRBC antibody levels in mice of the type in d, determined by flow cytometric analysis of SRBCs stained with immune sera, plotted as geoMFI. i, j, Number of Fas⁺GL7⁺ germinal centre cells and CD138^hiB220^int plasma cells in Listeria-OVA immunized CD28 KO mice that had received control (het) or EBI2 KO OTII cells, analysed at day 5. **P < 0.01 by ANOVA (g, h) or Student’s t-test (a, e, c, i, j). Data are representative of two independent experiments with at least three mice per group.