Lifestyle exercise attenuates immunosenescence; flow cytometry analysis.

Area of Science:

• Immunology
• Gerontology
• Exercise Science

Background:

• Immune system function declines with age (immunosenescence), influenced by physical activity levels.
• Cytomegalovirus (CMV) infection and age-related immune changes complicate the interaction between physical activity and immunity.
• Daily physical activity often decreases significantly in older adults, impacting immune health.

Purpose of the Study:

• To investigate if lifelong physical activity can attenuate or reverse immunosenescence in older adults.
• To determine the impact of sustained physical activity on T lymphocyte profiles in aging individuals.

Main Methods:

• Ninety-nine older adults (60-90 years) were categorized into physically active and inactive groups based on the 6-minute walk test (6WMT), Åstrand-Ryhming bike test (VO2max), and CHAMPS questionnaire.
• T lymphocyte subsets, including naive and memory T cells, were analyzed using eight-parameter flow cytometry.
• The CD4/CD8 T cell ratio and specific T cell populations (CD4+CD45RA+, CD4+CD45RO+) were compared between active and inactive participants.

Main Results:

• Physically active individuals showed a significantly healthier CD4/CD8 T cell ratio (≥1 or ≤2.5) compared to inactive individuals (<1).
• Higher 6WMT and VO2max scores correlated with increased percentages of CD4+CD45RA+ T lymphocytes and a higher CD4+CD45RA+/CD4+CD45RO+ ratio.
• Active older adults, even those with CMV infection, exhibited higher counts of CD4+CD45RA+ T lymphocytes than their inactive counterparts.

Conclusions:

• Lifestyle exercise can promote immune system rejuvenation in older adults.
• Sustained physical activity increases the proportion of naive T lymphocytes, contributing to a younger immune profile.
• Regular exercise helps mitigate the inverse CD4/CD8 T cell ratio, a marker of immune aging.