Thyroid Hormone Action on Innate Immunity.

Area of Science:

• Endocrinology
• Immunology
• Cellular Biology

Background:

• The relationship between thyroid hormones (THs) and the immune system is intricate and not fully elucidated.
• THs, including thyroxine (T4) and triiodothyronine (T3), are vital for both innate and adaptive immunity.
• Existing research presents complex and sometimes conflicting data on THs' immune effects.

Purpose of the Study:

• To review the cellular and molecular mechanisms of T4 and T3 actions on innate immune cells.
• To provide an overview of TH transport, metabolism, and action mechanisms within innate immune cells.
• To connect current knowledge of TH effects on innate immunity to adaptive responses and immunopathology.

Main Methods:

• Literature review of cellular and molecular mechanisms.
• Analysis of TH transport across cell membranes.
• Examination of intracellular TH metabolism.
• Investigation of genomic and non-genomic TH action pathways in innate immune cells.

Main Results:

• THs exert significant effects on various innate immune cell subsets.
• Mechanisms involve both cell-surface and intracellular actions of THs.
• TH transport and metabolism are critical for their immune cell modulation.

Conclusions:

• Understanding THs' role in innate immunity is key to comprehending adaptive immune responses.
• THs' influence on innate immunity has implications for inflammation, cancer, and autoimmunity.
• Further research is needed to fully clarify the complex interplay between the endocrine and immune systems.