Author:
Eken Ceylan,Sadallah Salima,Amicarella Francesca,Iezzi Giandomenica,Schifferli Jürg
Abstract
SummaryAccumulating evidence suggests an immune-modulatory role for platelets (PLT) and PLT-derived microvesicles. In particular, ectosomes, i.e. vesicles budding from PLT surface, have been shown to exert immunosuppressive activities on phagocytes. Here we investigated the effects mediated by PLT-derived ectosomes (PLT-Ecto) on CD4+ T cells. Exposure of activated CD4+ T cells to PLT-Ecto decreased their release of IFNγ, TNFα and IL-6, and increased the production of TGF-β1. Concomitantly, PLT-Ecto-exposed CD4+ T cells displayed increased frequencies of CD25high Foxp3+ cells. These phenomena were dose-dependent and PLT-Ecto specific, since they were not observed in the presence of polymorphonuclear- and erythrocyte-derived ectosomes. Analysis of specific T cell subsets revealed that PLT-Ecto induced differentiation of naïve T cells into Foxp3+ cells, but had no effect on predifferentiated Foxp3+ regulatory T cells (Tregs). Importantly, PLT-Ectoinduced Foxp3+ cells were as effective as peripheral blood Tregs in suppressing CD8+ T cell proliferation. PLT-Ecto-mediated effects were partly dependent on PLT-derived TGF-β1, as they were to some extent inhibited by PLT-Ecto pretreatment with TGF-β1-neutralising antibodies. Interestingly, ectosome-derived TGF-β1 levels correlated with Foxp3+ T cell frequencies in blood of healthy donors. In conclusion, PLT-Ecto induce differentiation of CD4+ T cells towards functional Tregs. This may represent a mechanism by which PLT-Ecto enhance peripheral tolerance.
Funder
Swiss National Science Foundation
Cited by
63 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献