Role of Th17 cells, Treg cells, and Th17/Treg imbalance in immune homeostasis disorders in patients with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide, following strokes and cardiovascular diseases. Chronic lung inflammation is believed to play a role in the development of COPD. In addition, accumulating evidence shows that the immune system plays a crucial role in the pathogenesis of COPD. Significant advancements have been made in research on the pathogenesis of immune diseases and chronic inflammation in recent years, and T helper 17 (Th17) cells and regulatory T (Treg) cells have been found to play a crucial role in the autoimmune response. Th17 cells are a proinflammatory subpopulation that causes autoimmune disease and tissue damage. Treg cells, on the other hand, have a negative effect but can contribute to the occurrence of the same disease when their antagonism fails. This review mainly summarizes the biological characteristics of Th17 cells and Treg cells, their roles in chronic inflammatory diseases of COPD, and the role of the Th17/Treg ratio in the onset, development, and outcome of inflammatory disorders, as well as recent advancements in immunomodulatory treatment targeting Th17/Treg cells in COPD.