Fig. 8

CardAP-EVs increase the frequency of regulatory T cells in anti-CD3 induced co-cultures of CD3⁺ cells with primed CD14⁺ cells. CD3⁺ and CD14⁺ cells were isolated by MACS and cultured unstimulated for 48 h. Here, CD14⁺ cells were additionally treated with either unstimulated (EVs) or cytokine stimulated (EVs^(cyt)) EVs, PBS in equal volume of the EVs (PBS) or left untreated. Afterwards, CD14⁺ cells were co-cultured 1:5 with CD3⁺ cells and stimulated with anti-CD3. After 3 days, the cells were harvested and analysed by flow cytometry. a Representative flow cytometric plots (Foxp3 vs CD25) display the frequencies of regulatory T cells (CD4⁺CD197⁻CD25⁺Foxp3⁺) in anti-CD3 stimulated co-cultures of CD3⁺ cells and CD14⁺ cells primed with PBS (left), EVs (middle) and EVs^(cyt) (right). b Quantitative analysis of regulatory T cell frequency is shown as median with interquartile range for the treatment with either CardAP-EV variant and PBS (n = 6; four different CardAP donors; four different PBMC donors). c Concentration of released IL-1RA by CD14⁺ cells after 2-days treatment with either CardAP EV variant or PBS is shown as median with interquartile range (n = 6, four different CardAP donors, four different PBMC donors). Friedman Test with Dunn´s multiple comparison test: ***p < .001, **p < .01, *p < .05 or Wilcoxon matched-pairs signed rank test; ^###p < .001, ^##p < .01, ^#p < .05