Circulating Exosomes Activate Dendritic Cells and Induce Unbalanced CD4+ T Cell Differentiation in Hashimoto...

Area of Science:

• Immunology
• Endocrinology
• Cell Biology

Background:

• Hashimoto thyroiditis (HT) is an autoimmune disease characterized by chronic inflammation of the thyroid gland.
• Circulating exosomes, small extracellular vesicles, are increasingly recognized for their role in intercellular communication and disease pathogenesis.

Purpose of the Study:

• To investigate the role of serum-derived exosomes in the inflammatory response associated with Hashimoto thyroiditis.
• To determine if exosomes from HT patients can activate immune cells and influence T lymphocyte differentiation.

Main Methods:

• Exosomes were isolated from the serum of HT patients and healthy controls.
• Exosome content (TPO, HSP60, MHC-II) was analyzed by Western blotting.
• Immune cell uptake of exosomes and subsequent activation (cytokine production, surface marker expression) were assessed using flow cytometry and immunofluorescence, with and without TLR inhibitors.

Main Results:

• Exosomes from HT patients showed higher levels of TPO, HSP60, and MHC-II compared to controls.
• HT exosomes were taken up by monocytes and dendritic cells (DCs), leading to DC activation via NF-κB signaling.
• HT exosomes promoted Th1/Th17 cell differentiation while suppressing Treg cells, increasing IL-17A and IFN-γ production and decreasing IL-10.

Conclusions:

• Serum exosomes from HT patients can act as antigen carriers, activating DCs through TLR2/3 pathways.
• This exosome-mediated immune activation contributes to CD4+ T lymphocyte differentiation imbalance, potentially driving Hashimoto thyroiditis development.
• Targeting exosome-TLR interactions may offer a therapeutic strategy for HT.