Figure 2: Donor-derived exosomes suppress Th2 inflammation in the allograft heart tissue.

Mice were transplanted with allograft hearts. The recipient mice were treated as denoted above each column. Exosome: Mice received donor-derived exosomes. #, non-donor-derived exosomes. PAR2-n: The recipient mice are PAR2-deficient mice. (A1-A8) the representative images show the heart histology and the mononuclear cell infiltration (the cells were stained in dark blue) in heart tissue. (B) the mononuclear cells were isolated from the heart tissue and analyzed by flow cytometry. The gated dot plots indicate that the CD4⁺ CD25⁺ T cells. (C1-C5) the gated histograms show the frequency of IL-4⁺ CD4⁺ T cells. (D) the bars indicate the IL-4 levels in the culture supernatant (by ELISA; the data are presented as mean ± SD. *p < 0.01, compared to the group (C1) the group labels on the Y axis are the same as the histograms of (C1-C8). (E1-E5) the gated histograms show the frequency of IFN-γ⁺ CD4⁺ T cells. (F1-F5), the gated histograms show the frequency of proliferating CD4⁺ T cells after incubating with spleen DCs (DC:T cell = 1:5) and mouse heart extracts (1 μg/ml) for 3 days. Each group consists of 12 mice. Samples from 4 mice were pooled as one sample. The data are representatives of 3 independent experiments.