Figure 1. Tonsillar Nrp1⁺ CD4⁺ T cells have a Tfh phenotype in vivo.

(A) Representative flow cytometry analysis of Nrp1 and CD25, Foxp3, CD69, CCR7 and CD45RA co-expression on tonsillar CD3⁺ CD4⁺ T cells population. (B) CD25 and Foxp3 co-expression on tonsillar CD3⁺ CD4⁺ Nrp1⁺ and Nrp1^- T cell populations. (C-F) Nrp1 expression on tonsillar Tfh cells and non-Tfh cells, defined as CD3⁺ CD4⁺ CXCR5⁺ PD-1⁺ and CD3⁺ CD4⁺ CXCR5^- PD-1^- respectively (C-D), or CD3⁺ CD4⁺ CXCR5⁺ ICOS^hi and CD3⁺ CD4⁺ CXCR5^- ICOS^lo respectively (E-F). Numbers in flow cytometry plots indicate the mean percentage ± SD of Tfh cells in CD4⁺ T cells (left) and of Nrp1⁺ cells in Tfh cells (middle) and non-Tfh cells (right) (n=10 tonsils). (G-H) Nrp1 expression on tonsillar CD3⁺ CD4⁺ CXCR5⁺ CD57⁺ and CD3⁺ CD4⁺ CXCR5^- CD57^- Tfh cells. Data were compared using Student’s impaired t-test (**: p≤0.01, ***: p≤0.001).