Extracellular vesicles from regenerative human cardiac cells act as potent immune modulators by priming monocytes

Abstract

Background: Nano-sized vesicles, so called extracellular vesicles (EVs), from regenerative cardiac cells represent a promising new therapeutic approach to treat cardiovascular diseases. However, it is not yet sufficiently understood how cardiac-derived EVs facilitate their protective effects. Therefore, we investigated the immune modulating capabilities of EVs from human cardiac-derived adherent proliferating (CardAP) cells, which are a unique cell type with proven cardioprotective features. Results: Differential centrifugation was used to isolate EVs from conditioned medium of unstimulated or cytokinestimulated (IFNγ, TNFα, IL-1β) CardAP cells. The derived EVs exhibited typical EV-enriched proteins, such as tetraspanins, and diameters mostly of exosomes (< 100 nm). The cytokine stimulation caused CardAP cells to release smaller EVs with a lower integrin ß1 surface expression, while the concentration between both CardAP-EV variants was unaffected. An exposure of either CardAP-EV variant to unstimulated human peripheral blood mononuclear cells (PBMCs) did not induce any T cell proliferation, which indicates a general low immunogenicity. In order to evaluate immune modulating properties, PBMC cultures were stimulated with either Phytohemagglutin or anti-CD3. The treatment of those PBMC cultures with either CardAP-EV variant led to a significant reduction of T cell proliferation, pro-inflammatory cytokine release (IFNγ, TNFα) and increased levels of active TGFβ. Further investigations identified CD14 + cells as major recipient cell subset of CardAP-EVs. This interaction caused a significant lower surface expression of HLA-DR, CD86, and increased expression levels of CD206 and PD-L1. Additionally, EV-primed CD14 + cells released significantly more IL-1RA. Notably, CardAP-EVs failed to modulate anti-CD3 triggered T cell proliferation and pro-inflammatory cytokine release in monocultures of purified CD3 + T cells. Subsequently, the immunosuppressive feature of CardAP-EVs was restored when anti-CD3 stimulated purified CD3 + T cells were co-cultured with EV-primed CD14 + cells. Beside attenuated T cell proliferation, those cultures also exhibited a significant increased proportion of regulatory T cells. Conclusions: CardAP-EVs have useful characteristics that could contribute to enhanced regeneration in damaged cardiac tissue by limiting unwanted inflammatory processes. It was shown that the priming of CD14 + immune cells by CardAP-EVs towards a regulatory type is an essential step to attenuate significantly T cell proliferation and proinflammatory cytokine release in vitro.

Human airway epithelial extracellular vesicle miRNA signature is altered upon asthma development

“…Albeit, as EVs contain surface molecules such as HLA‐DR, we figured that the cellular interaction might be subject‐specific and thus question the use of DCs from different human donors. It has however been shown several times that miRNAs can be functionally transferred to target cells and that DC function is modulated by EVs . Thus, it is intriguing to speculate that sEVs‐associated epithelial miRNAs are involved in regulating the immune responses by underlying DCs.…”

“…It has however been shown several times that miRNAs can be functionally transferred to target cells [48][49][50][51][52][53] and that DC function is modulated by EVs. [54][55][56] Thus, it is intriguing to speculate that sEVs-associated epithelial…”

Exosome-based biomimetic nanoparticles targeted to inflamed joints for enhanced treatment of rheumatoid arthritis

“…In this study, we derived the exosomes from RAW264.7 macrophages because in ammatory lesions in RA contain abundant activated macrophages, and target cells appear to internalize exosomes better when these exosomes have been derived from the same cell type [26,[34][35][36]. Furthermore, it was reported that exosomes derived from macrophages have achieved excellent therapeutic e cacy in the treatment of other in ammations [20,22].…”

Cardiac Extracellular Vesicles (EVs) Released in the Presence or Absence of Inflammatory Cues Support Angiogenesis in Different Manners

“…Furthermore, CardAP cells displayed a set of other cardioprotective effects, including immunomodulation and the improvement of heart functions in virus or angiotensin II induced cardiovascular disease models [36][37][38][39]. Since we were already able to show that the immune modulating effect of CardAP cells is partially facilitated by their released EVs [40], it would be of further interest if the cardioprotective feature of enhancing angiogenesis is also facilitated by CardAP-EVs. This knowledge would be useful for a future therapeutic cell-free approach for the treatment of cardiovascular diseases by using CardAP-EVs.…”

“…The size, phenotype and immune modulating capacity of CardAP-EVs has been recently determined [40]. In this study, we focused on the interaction between CardAP-EVs and cardiovascular target cells to determine their impact on angiogenesis as a means to further evaluate their potential as a tool for treating heart diseases.…”