<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Autoimmune thyroid diseases (AITD) mainly include Hashimoto’s thyroiditis (HT) and Graves’ disease (GD), which are characterised by the presence of circulating antibodies against various thyroid autoantigens and infiltration of the thyroid gland by autoreactive lymphocytes. Despite the significant advancement in the knowledge of AITD pathogenesis in the last decade, the specific immunological mechanisms responsible for development of the disease are not thoroughly understood. Classically, HT has long been considered as a T helper (Th)1-mediated disease, while a Th2-driven autoimmune response is dominant for GD development. However, this classification has changed due to the description of Th17 lymphocytes, which suggested participation of these cells in AITD, particularly HT pathogenesis. Moreover, a shift in the balance between Th17 and T regulatory (Treg) cells has been observed in thyroid autoimmunity. We have observed overexpression of IL-17, the prominent effector cytokine of Th17, within thyroid tissues from HT and GD patients in our studies. The present review will focus on recent data regarding the role of Treg and Th17 lymphocytes in AITD pathogenesis. In addition, the impact and proposed mechanisms of the predominant environmental factors triggering the autoimmune response to the thyroid will be discussed.</p></abstract>

Autoimmune thyroid diseases (AITD) mainly include Hashimoto’s thyroiditis (HT) and Graves’ disease (GD), which are characterised by the presence of circulating antibodies against various thyroid autoantigens and infiltration of the thyroid gland by autoreactive lymphocytes. Despite the significant advancement in the knowledge of AITD pathogenesis in the last decade, the specific immunological mechanisms responsible for development of the disease are not thoroughly understood. Classically, HT has long been considered as a T helper (Th)1-mediated disease, while a Th2-driven autoimmune response is dominant for GD development. However, this classification has changed due to the description of Th17 lymphocytes, which suggested participation of these cells in AITD, particularly HT pathogenesis. Moreover, a shift in the balance between Th17 and T regulatory (Treg) cells has been observed in thyroid autoimmunity. We have observed overexpression of IL-17, the prominent effector cytokine of Th17, within thyroid tissues from HT and GD patients in our studies. The present review will focus on recent data regarding the role of Treg and Th17 lymphocytes in AITD pathogenesis. In addition, the impact and proposed mechanisms of the predominant environmental factors triggering the autoimmune response to the thyroid will be discussed.

Immunological Mechanisms of Autoimmune Thyroid Diseases: A Shift in The Traditional TH1/TH2 Paradigm

Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences.

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Autoimmune thyroid diseases (AITD) mainly include Hashimoto’s thyroiditis (HT) and Graves’ disease (GD), which are characterised by the presence of circulating...

Immunological Mechanisms of Autoimmune Thyroid Diseases: A Shift in The Traditional TH1/TH2 Paradigm

Published Online: Apr 07, 2019

Page range: 67 - 77

Received: Nov 12, 2018

Accepted: Feb 05, 2019

DOI: https://doi.org/10.2478/prolas-2019-0012

Keywords
Hashimoto’s thyroiditis, Graves disease, T helper 17 cell, T regulatory cell, environmental factors

© 2019 Tatjana Zaķe et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Immunological Mechanisms of Autoimmune Thyroid Diseases: A Shift in The Traditional TH1/TH2 Paradigm

Published Online: Apr 07, 2019

Page range: 67 - 77

Received: Nov 12, 2018

Accepted: Feb 05, 2019

DOI: https://doi.org/10.2478/prolas-2019-0012

KeywordsHashimoto’s thyroiditis, Graves disease, T helper 17 cell, T regulatory cell, environmental factors

© 2019 Tatjana Zaķe et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Keywords
Hashimoto’s thyroiditis, Graves disease, T helper 17 cell, T regulatory cell, environmental factors