Fig. 4

Regulatory effect of m/lEVs in B cells from patients with RA. A Representative contour plots of the CD86 expression in B cells from patients with RA, cultured for 24 h without stimulation (unstimulated, Unst) or with anti-BCR in the absence or presence of m/lEVs from HD (HD-m/lEVs), patients with RA (PRA-m/lEVs), and patients with RA-forming immune complexes (PRA-m/lEV-ICs). B The frequency of CD69⁺ (left panel), CD80⁺ (center panel), and CD86⁺ (right panel) B cells, cultured for 24 h without stimulation or with anti-BCR in the absence or presence of HD-m/lEVs, PRA-m/lEVs, or PRA-m/lEVs-ICs. Data of five patients with RA and median are shown. C The frequency of CD69⁺ (left panel), CD80⁺ (center panel), and CD86.⁺ (right panel) B cells, cultured for 72 h without stimulation or with anti-BCR and CpG in the absence or presence of HD-m/lEVs, PRA-m/lEVs, or PRA-m/lEVs-ICs. Data of six patients with RA and median are shown. D The frequency of proliferating B cells cultured of 72 h without stimulation or with anti-BCR and CpG in the absence or presence of HD-m/lEVs, PRA-m/lEVs, or PRA-m/lEVs-ICs. Data of six patients with RA and median are shown. E Kinetic of calcium mobilization of total B cells based on the ratio of Indo 1 AM bound/unbound in total B cells. After 30 s of acquisition, the B cells were stimulated with anti-BCR in the presence or absence of HD-m/lEVs, PRA-m/lEVs, or PRA-m/lEVs-ICs (indicated with an arrow). The mean of five patients with RA is shown. In the inserted small figure, the linear slopes of calcium mobilization in total B cells at 30 − 90-s period (linear) are shown. Data of five patients with RA and median are shown. F Area under the curve of calcium mobilization at the baseline (left panel), incremental (center panel), and post-incremental (right panel) phases of B cells. Data of five patients with RA and median are shown. G The median fluorescence intensity (MFI) of tyrosine phosphorylation (p-Tyr) in B cells without stimulation or with anti-IgM in the presence or absence of HD-m/lEVs, PRA-m/lEVs, or PRA-m/lEV-ICs. Data of five patients with RA and median are shown. B–G Kruskal − Wallis test with Dunn’s post-test. * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001