Fig. 1

Majority of TFRs localize outside of the germinal center. A Gating strategy for total TFRs (CXCR5^hi/+PD1^hi/+CD25⁺CD127⁻) within CD4⁺ T cells in paired PB and LN samples and PD-1 and CXCR5 FMOs. B Representative flow cytometry plot showing total TFR frequencies in LN vs PB. C Summary plot showing the frequency of total TFR in LN PB samples of healthy controls D Representative flow cytometry plots showing proportion of f-TFR (PD-1^hiCXCR5^hiCD25⁺CD127⁻) and exf-TFR (PD1⁺CXCR5⁺CD25⁺CD127⁻) within CD4⁺ T cells in LNs. E Representative plot demonstrating overlay of CD25⁺ CD127⁻ populations and FOXP3⁺ (red) populations together with CD25⁻ CD127⁺ and FOXP3⁻ (grey) populations. F Summary plots comparing proportion of f-TFR and exf-TFR. G Representative image of immunoflouresently stained LN sections from an HIV infected subject with zoomed-in images below, LNs were stained with antibodies to BCL-6 (green), CD4 (red) and FOXP3 (yellow). Images were scanned at × 20 magnification and scale bars equal 100 μm. H CD4⁺FOXP3⁺ cells were quantified in the entire LN cross-section and within GCs of LNs from 6 HIV uninfected and 28 HIV-infected subjects. TissueQuest (TissueGnostics, Vienna) was used to compute CD4⁺FOXP3⁺ density in each tissue section. P values were determined using Mann–Whitney U test