Fig. 3: Transcriptome profiling of thymic CD21⁻CD35⁻ and CD21⁺CD35⁺ B cell subsets in human neonates.

a Heatmap representation of selected genes differentially expressed between thymic CD21⁻CD35⁻ B cell subset (left side) and CD21⁺CD35⁺ B cell subset (right side) involved in B cell activation, class-switch recombination, proliferation, and plasma cell differentiation. Gene values were expressed as normalized row z-score of log2 gene expression values (n = 5). Two-sided Wald test with Benjamini–Hochberg false discovery ration (FDR) adjustment. b Frequency of CD80⁺, CD86⁺, PD1⁺, KI67⁺, CD138⁺, XBP1⁺, BLIMP1⁺, and BCMA⁺ cells within CD19⁺CD21⁻CD35⁻ and CD19⁺CD21⁺CD35⁺ subsets in the thymus of neonates and infants aged 1 day–4 months, measured by flow cytometry (n = 5). Bars are defined as mean values ± SD. Two-sided t-test was performed. c Heatmap representation of transcripts of immunoglobulin genes in CD19⁺CD21⁻CD35⁻ and CD19⁺CD21⁺CD35⁺ thymic B cells. Gene values were expressed as normalized row z-score of log2 gene expression values. Two-sided Wald test with Benjamini–Hochberg false discovery ration (FDR) adjustment. d Frequency of IgD⁺IgM⁺, IgG⁺, IgA⁺, and IgE⁺ cells within CD19⁺CD21⁻CD35⁻ and CD19⁺CD21⁺CD35⁺ subsets in the thymus of neonates and infants aged 1 day–4 months, measured by flow cytometry (n = 5). Bars are defined as mean values ± SD. Two-sided t-test was performed. e Protein levels of different classes and subclasses of immunoglobulins in CD19⁺CD21⁻CD35⁻ and CD19⁺CD21⁺CD35⁺ thymic B cells measured by iST proteomics and expressed as protein label-free quantification (LFQ, n = 3; ND = no detected). Bar charts are defined as mean values, dots are individual values. Two-sided t-test was performed.