Fig. 1

SEMA4A is highly expressed in antigen-presenting cells (APCs) and CRTH2⁺ Th2 memory T cells. a, b Quantification of SEMA4A mRNA in different human haematopoietic cell types. The indicated human haematopoietic cell types were purified, and total RNA was isolated from each cell population for chip hybridization. Bars show the relative SEMA4A mRNA expression in each cell subset (a). Real-time PCR was performed to confirm the expression of SEMA4A mRNA in CD19⁺ B cells, CD4⁺CD11c⁺myeloid dendritic cells (mDCs), as well as naive (Tn), central memory (Tcm), effector memory (Tem), and Th2 memory CD4⁺ T cells. The relative fold differences in SEMA4A mRNA expression between samples are indicated on the y-axis. Error bars represent the standard error of mean (s.e.m.) of different wells. Data represent one of five donors in each independent experiment, which were repeated three times. b, c Flow cytometry analysis of SEMA4A expression on different populations of CD19⁺ B cells, CD4⁺ DC, and CD4⁺ T cells. Enriched CD4⁺ T cells from peripheral blood are sorted into CD45RA⁺ naive, CRTH2⁺ memory Th2, and CRTH2⁻ memory CD4⁺ T cells. CD4⁺ conventional dendritic cells (cDCs) are gated as Lin⁻CD4⁺BDCA1⁺ cells in CD4⁺ enriched tonsil cell; B cells are gated as CD19⁺ tonsil cells. The numbers in the dot plots indicate the percentage of cells in that gate. Open histograms represent the staining of indicated cell subsets with anti-SEMA4A mAb; filled histograms represent the isotype. Data represent one of three independent experiments. d, e Histological analysis of SEMA4A expression in human tonsil. Tonsil tissue sections were stained with anti-SEMA4A mAb followed by Horseradish Peroxidase (HRP)-conjugated goat anti-mouse antibody. Magnifications used for pictures are ×10 (left) with scale bar representing 500 μm and ×20 (right) with scale bar representing 200 μm (b); or double immunofluorescence stained with anti-SEMA4A mAb (red) and anti-CD11c mAb (green). Magnifications used for pictures are ×200 (left) with scale bar representing 20 μm and ×400 (right) with scale bar representing 10 μm (e). Germinal center (GC), follicular mantle zone (FM), and interfollicular T-cell zone (TZ) were indicated. Data represent one of four independent experiments