Fig 2: CD19 can be found on T cells but is not endogenously expressed.a, b Representative flow cytometric staining of CD19 on CD4+ and CD8+ T cells and B cells isolated from a wild type and CD19-deficient CD19-cre mice or b healthy control peripheral blood mononuclear cells (PBMC). c, d Bulk RNA sequencing of fluorescence-activated cell (FACS)-sorted B and T cells for the CD19 transcript shown as TPM, reads per kilobase of transcript per million reads mapped; c n = 3 mice for B cells and 8 mice per T cells, analyzed via two-tailed unpaired Student’s t-test with Welch’s correction and Bonferroni correction for multiple testing; d n = 4 healthy human donors; one set of B and T cells per mouse or human, analyzed via two-tailed Mann-Whitney test with Bonferroni correction for multiple testing; displayed as box plot; e Mean fluorescence intensity (MFI) of CD19 of CD4+ T cells of splenocyte cultures isolated from wild type mice or myelin oligodendrocyte glycoprotein (MOG)35–55 peptide T cell receptor (TCR) transgenic 2D2 mice stimulated with anti-CD3/anti-CD28 antibodies for 48 h; n = 3 wells per group. f Flow cytometric analysis of CD19 on CD4+ and CD8+ T cells from the spleens of wild type, CD19-deficient CD19-cre, and B cell-deficient µMT mice; n = 3 per group; analyzed via Brown-Forsythe and Welch ANOVA with Dunnett’s T3 multiple comparisons test. g MFI of CD19 of CD3+ T cells and h percentage of CD20+ B cells in murine spleens during development; n = 3 mice for groups 1-3 weeks and 7 mice for the <8 group; analyzed via Brown-Forsythe and Welch ANOVA with Holm-Sidak’s multiple comparisons test. All figures are representative of a, b, e–h or pooled from c, d 2-4 independent experiments; data displayed as means ± SD; box plots are min to max with means ± SD; *=p < 0.05; **=p < 0.01; ***=p < 0.001; ****=p < 0.0001.