Author(s): KWAK, Y., Institution: DONG-EUI UNIV, Country: KOREA, SOUTH, Abstract-ID: 671

INTRODUCTION:
Metabolic disturbances, including obesity, hypertriglyceridemia, and hyperlipidemia, have been shown to induce functional alterations in Tregs, which may be particularly relevant in patients with long COVID-19 syndrome. Recent studies have emphasized the importance of a healthy diet, lifestyle modification, and exercise interventions in enhancing immune resilience against SARS-CoV-2 infection over the long term. Exercise, in particular, has been proposed as a non-pharmacological strategy capable of modulating immune regulation, inflammatory balance, and host susceptibility through pathways potentially involving angiotensin-converting enzyme 2 (ACE2). Therefore, the present study aimed to investigate the frequency and functional characteristics of Tregs in relation to obesity, lifestyle factors, and stress, as well as to examine the effects of exercise intervention on these immune parameters and ACE2 expression.
METHODS:
Based on our previous research findings, Medline, Embase, Global Health (Ovid), CINAHL (EBSCO), PubMed, Scopus, Web of Science, and Google Scholar were systematically searched to identify studies addressing the definition, underlying mechanisms, and pathophysiology of long COVID-19, as well as to evaluate the effects of rehabilitation and exercise interventions on regulatory T cell (Treg) function and angiotensin-converting enzyme 2 (ACE2).
RESULTS:
Immune parameters have been extensively investigated in both humans and animal models under conditions of chronic stress, and these studies have demonstrated that chronic immobilization stress significantly increases the suppressive function of CD4⁺CD25⁺ regulatory T cells (Tregs). Metabolic disturbances, including obesity, hyperlipidemia, and elevated triglyceride levels, alter Treg function through metabolic reprogramming mediated by Akt2 activation, thereby promoting Treg plasticity and impairing FoxP3⁺ T cell stability. Notably, activation of Akt2 is sufficient to drive the production of inflammatory cytokines by Tregs. Collectively, these findings suggest that exercise-mediated modulation of Treg function may play an important role in attenuating inflammation and immune dysregulation associated with asthma, allergic inflammation, autoimmunity, tumor immunity, and long COVID-19 syndrome.
CONCLUSION:
Our findings demonstrate a persistent hyperlipidemic phenotype in individuals with long COVID-19, accompanied by signs of chronic inflammation and altered lipoprotein metabolism that differ between acute and chronic inflammatory states. Based on these observations, a rehabilitation-based multicomponent exercise intervention program (4–5 days per week, 35–60% heart rate reserve, 100–250 minutes of aerobic exercise per week) may be particularly beneficial for patients with post- and long COVID-19 syndrome. Such programs should be complemented by psychological support strategies, including meditation and mindfulness-based interventions (MBIs).