Regulatory T cell activation, proliferation, and reprogramming induced by extracellular vesicles

Area of Science:

• Immunology
• Cardiology
• Cell Biology

Background:

• Extracellular vesicles (EVs) from heart stromal/progenitor cells are known to modulate innate immunity with benefits in cardiac disease models.
• The impact of these EVs on adaptive immunity remains largely unexplored.

Purpose of the Study:

• To investigate the effects of heart-derived EVs on the differentiation, proliferation, and cytokine production of CD4+ T cell subsets (Th1, Th2, Th17, Treg).
• To evaluate the therapeutic potential of these EVs in an in vivo model of cardiac inflammation, specifically experimental autoimmune myocarditis (EAM).

Main Methods:

• Ex vivo differentiation of naive CD4+ T cells was performed to assess EV influence on T cell subsets.
• In vivo studies utilized the experimental autoimmune myocarditis (EAM) model to evaluate the therapeutic effects of EVs.

Main Results:

• Heart-derived EVs selectively promote the proliferation and IL-10 production of regulatory T (Treg) cells, inducing a FOXP3+RORγt+ phenotype.
• In the EAM model, EVs attenuated cardiac inflammation and improved cardiac function, correlating with an increase in splenic IL-10+ Treg cells.

Conclusions:

• EVs from heart stromal/progenitor cells possess immunomodulatory properties, particularly enhancing Treg cell activity.
• EV-mediated T cell modulation presents a promising therapeutic avenue for inflammatory conditions, including autoimmune disorders and transplantation-related complications, by leveraging endogenous immunosuppressive mechanisms.