Redox-Immune Axis and Ozone Pollution: From Oxidative Stress to Thymic Involution and Neurodegeneration

Chronic exposure to low concentrations of ozone leads to oxidative stress, which disrupts immune regulation. The thymus gland plays a crucial role in the maturation and differentiation of T lymphocytes, cells essential for the body's defense and immune tolerance. In the early years of life, the thymus is highly active, but after adolescence, it undergoes a process known as thymic involution. This process involves a reduction in the size and functionality of the thymus, which is gradually replaced by adipose tissue. Ozone pollution exacerbates this involution and impairs the thymus's proper function. Consequently, thymic cells may alter their function, leading to a decreased production and diversity of T lymphocytes. This decrease contributes to the establishment of chronic inflammatory states, autoimmunity, and a reduced capacity to respond to infections. Immune dysfunction and chronic inflammation can further result in the development and progression of neurodegenerative diseases. Moreover, thymic involution, exacerbated by environmental factors and oxidative stress, negatively impacts overall immunity and accelerates the progression of degenerative diseases over time. This review aims to explore the relationship between oxidative stress and its impact on the thymus gland. We hypothesize that understanding the relationship between ozone pollution and disruption of the redox-immune axis is crucial for understanding the role of the thymus in senescence and neurodegenerative diseases. To explore this topic, we conducted a review from 2006 to 2025, utilizing several databases, including PubMed, Scopus, Google Scholar, EBSCO, and Web of Science.