Fig. 3a–c

Tfh cell proliferation monitored by CFSE labelling. CD4⁺CXCR5⁺ Tfh cells of C57BL/6 normal mice were sorted by flow cytometry, and CD11b⁺Gr-1⁺ MDSC of Schistosoma japonicum-infected C57BL/6 mice were sorted by the Myeloid-Derived Suppressor Cell Isolation Kit. CFSE-labelled Tfh cells (1 × 10⁵/well) were cultured either unstimulated (a), stimulated with anti-CD3 (5 μg/ml) and anti-CD28 (2 μg/ml) (b), or stimulated with anti-CD3 (5 μg/ml) and anti-CD28 (2 μg/ml) plus MDSC (2 × 10⁵/well) (c). Cells were harvested after 5 days to analyse the CFSE fluorescence intensity of Tfh by flow cytometry. For abbreviations, see Figs. 1 and 2