Modulating the function of the immune system by thyroid hormones and thyrotropin

- There is a close bidirectional communication between the neuroendocrine and immune systems.
- Alterations in the levels of THs can significantly affect the function of the immune system.
- Thyroid hormones can exert responses in various immune cells, e.g., monocytes, macrophages, natural killer cells, and lymphocytes.
- Thyroid Hormones have an important role in Inflammation, Autoimmunity and Pathogen Clearance.

Accumulating evidence suggests a close bidirectional communication and regulation between the neuroendocrine and immune systems. Thyroid hormones (THs) can exert responses in various immune cells, e.g., monocytes, macrophages, natural killer cells, and lymphocytes, affecting several inflammation-related processes (such as, chemotaxis, phagocytosis, reactive oxygen species generation, and cytokines production). The interactions between the endocrine and immune systems have been shown to contribute to pathophysiological conditions, including sepsis, inflammation, autoimmune diseases and viral infections. Under these conditions, TH therapy could contribute to restoring normal physiological functions. Here we discuss the effects of THs and thyroid stimulating hormone (TSH) on the immune system and the contribution to inflammation and pathogen clearance, as well as the consequences of thyroid pathologies over the function of the immune system.