Role of Regulatory T Cells in Pulmonary Ageing and COPD Development

Chronic obstructive pulmonary disease (COPD) is recognized as a long-term inflammatory lung condition, predominantly resulting from smoking tobacco. While all smokers exhibit some level of pulmonary inflammation, only about 15-20% go on to develop significant COPD, indicating that specific individual factors may enhance these inflammatory responses and contribute to the disease's progression. T regulatory cell (Treg) activity is crucial in mediating pulmonary inflammation in COPD. With accumulating evidence supporting the autoimmune characteristics of COPD, there has been an increasing focus on the role Treg cells play in the disease's initiation and development. This article aims to review the existing literature regarding Treg cells and their influence on COPD pathogenesis and lung ageing. Treg-mediated suppression is a critical mechanism in the negative regulation of immune-related inflammation, which is significant in various disorders, including autoimmunity, allergies, infections (both acute and chronic), and cancer. The lungs of ageing individuals often resemble those affected by COPD, leading to the perception of COPD as a condition that accelerates lung ageing. Changes in Treg cells with age correspond to decreased adaptive immune responses and a higher likelihood of immune-related disorders. The increased presence of Treg cells in older adults may help explain several immunological conditions commonly associated with ageing, which include malignancies, infections, and COPD.