Aging, persistent viral infections, and immunosenescence: can exercise “make space”? Exerc Sport Sci Rev. 2011;39:23-33. [PMID: 21088603 DOI: 10.1097/jes.0b013e318201f39d]

Intra-apheresis Cycling to Improve the Clinical Efficacy of Peripheral Blood Stem Cell Donations

Peripheral blood stem cell (PBSC) donation is the primary procedure used to collect haemopoietic stem cells (HSCs) for transplantation in individuals with haematological malignancies. More than 90,000 HSC transplants take place globally each year, and there is an increasing need to guarantee HSC mobilisation, improve tolerability to apheresis, and optimise immune reconstitution. Currently, mobilisation of HSCs depends upon pharmacological agents, with donors inactive during their subsequent apheresis. A successful yield of HSCs is not always achieved, and greater efficiency of collection procedures would improve the donors' safety and experience, along with the overall functioning of apheresis departments. The mobilisation of immune cells during bouts of exercise has been increasingly studied over the past 40 years. Exercise enriches peripheral blood with HSCs and immune cells such as cytolytic natural killer cells, and these may impact upon collection efficiency and patient outcomes following transplantation. Using exercise in conjunction with routine pharmaceutical agents may meet these needs. This article describes the impact of exercise on the quantity and engraftment potential of HSCs. Given that PBSC collections take on average 3-4 h per day per donor, and often consecutive days to complete, particular attention is paid to adopting interval exercise in this setting. Moreover, practical and safety considerations for allogeneic and autologous donors are discussed. 'Intra-apheresis cycling' is proposed as a feasible adjunctive strategy to evoke clinically significant improvements in the quality of the immune graft. Further research is needed to validate this concept in conjunction with routine mobilisation agents.

The effects of acute and chronic exercise on immune markers of TH1/TH2 cells in older adults: a systematic review

Purpose

Imbalance between Th1 and Th2 cells correlated with increased disease incidence, is well-documented in the older adult. Both acute and chronic exercise induce a transient shift in organic homeostasis, modulating the immune system and impacting the balance between Th1 and Th2 cells. This review investigates the impact of acute and chronic exercise on immune markers of Th1 and Th2 cells in the older adults.

Methods

This study was conducted as a systematic review, following PRISMA guidelines, databases including PubMed, Web of Science, Embase, Science Direct, and Scopus were searched until March 2024, identifying randomized controlled trials and prospective observational studies that examined the effects of acute and chronic exercise on intracellular and surface markers, cytokines, and immunoglobulins in older adults. Studies involving animal subjects, isolated cells, diseased patients, or exposure to medications and drugs were excluded. The quality of the selected studies was assessed using the Cochrane risk of bias tool (ROB2), with data organized and presented in tables and figures.

Results

Fourteen studies with 525 participants were included in the analysis. An acute session significantly increased serum IL-4, IL-6, and IL-10 levels immediately afterward, returning to baseline within 1 hour at moderate to high intensities. Chronic exercise at moderate to high intensities reduced serum TNF-α, IL-6, and the CD4/CD8 ratio, while increasing IL-10 levels after 24 weeks. Intracellular, other surface markers and cytokines, and immunoglobulins were not analyzed.

Conclusion

Chronic exercise decreases serum TNF-α and IL-6 levels, lowers the CD4/CD8 ratio, and increases IL-10 after 24 weeks, aiding Th1 and Th2 balance. Acute exercise temporarily increases serum IL-4, IL-6, and IL-10 levels, returning to baseline within an hour, indicating short-term immune modulation of Th1/Th2 balance.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021244426, Identifier CRD42021244426.

Exercise intensity and training alter the innate immune cell type and chromosomal origins of circulating cell-free DNA in humans

Exercising regularly promotes health, but these benefits are complicated by acute inflammation induced by exercise. A potential source of inflammation is cell-free DNA (cfDNA), yet the cellular origins, molecular causes, and immune system interactions of exercise-induced cfDNA are unclear. To study these, 10 healthy individuals were randomized to a 12-wk exercise program of either high-intensity tactical training (HITT) or traditional moderate-intensity training (TRAD). Blood plasma was collected pre- and postexercise at weeks 0 and 12 and after 4 wk of detraining upon program completion. Whole-genome enzymatic methylation sequencing (EM-seq) with cell-type proportion deconvolution was applied to cfDNA obtained from the 50 plasma samples and paired to concentration measurements for 90 circulating cytokines. Acute exercise increased the release of cfDNA from neutrophils, dendritic cells (DCs), and macrophages proportional to exercise intensity. Exercise training reduced cfDNA released in HITT participants but not TRAD and from DCs and macrophages but not neutrophils. For most participants, training lowered mitochondrial cfDNA at rest, even after detraining. Using a sequencing analysis approach we developed, we concluded that rapid ETosis, a process of cell death where cells release DNA extracellular traps, was the likely source of cfDNA, demonstrated by enrichment of nuclear DNA. Further, several cytokines were induced by acute exercise, such as IL-6, IL-10, and IL-16, and training attenuated the induction of only IL-6 and IL-17F. Cytokine levels were not associated with cfDNA induction, suggesting that these cytokines are not the main cause of exercise-induced cfDNA. Overall, exercise intensity and training modulated cfDNA release and cytokine responses, contributing to the anti-inflammatory effects of regular exercise.

Combined Training Improves Gene Expression Related to Immunosenescence in Obese Type 2 Diabetic Individuals

Purpose: The aim of this study was to investigate the effects of moderate combined training (CT) on both the gene expression of pro- and anti-inflammatory markers and senescence in the immune system in peripheral blood mononuclear cells (PBMCs) and subcutaneous adipose tissue (SAT) of obese middle-aged individuals with type 2 diabetes (T2D). Methods: Thirty obese individuals (50.2 ± 9.4 years; body mass index: 31.8 ± 2.3 kg/m²) with T2D underwent 16 weeks of a CT group [CT; aerobic (50-60% of VO2max) plus resistance (50-75% of 1RM) training; 3 times/week, 70 min/session; n = 16)] or a control group (CG, n = 14). Nutritional patterns, muscle strength (1RM), cardiorespiratory fitness (VO2max), waist circumference (WC), body composition (Air Displacement Plethysmograph) and blood collections for biochemical (serum leptin, IL-2, IL-4, IL-6, IL-10, TNF-α and anti-CMV) and molecular (gene expression of leptin, IL-2, IL-4, IL-6, IL-10, TNF-α, PD-1, P16ink4a, CCR7, CD28 and CD27 in PBMCs and SAT) analyses were assessed before (Pre) and after (Post) the 16 weeks of the experimental period. Results: Significant decreases were observed in WC and IL4, TNF-α, PD-1 and CD27 expression in PBMCs for CT. Furthermore, significant increases were observed in 1RM and VO2max for CT after the experimental period. Conclusion: Moderate CT contributed to a reduction in the gene expression of markers associated to chronic inflammation and immunosenescence in PBMCs of obese middle-aged individuals with T2D.

Inflammation-Related Genes Are Differentially Expressed in Lipopolysaccharide-Stimulated Peripheral Blood Mononuclear Cells after 3 Months of Resistance Training in Older Women

Recently, we showed that three months of resistance exercise significantly alters 18 canonical pathways related to chronic inflammation in PBMCs of older adults. In this exploratory sub-study, the aim is to explore whether resistance exercise enhances the PBMCs stress response by mimicking an acute infection through in vitro LPS stimulation. Women (≥65 years) were randomly divided into intensive strength training (IST), strength endurance training (SET), or flexibility training (as control group, CON) groups. PBMCs were isolated and cultured with and without LPS for 24 h. Their RNA was analyzed via targeted RNA sequencing of 407 inflammation-related genes, with relevant fold-changes defined as ≤0.67 or ≥1.5 (3 months vs. baseline). A pathway analysis using ingenuity pathway analyses identified significant pathways among 407 genes with p < 0.05 and z-scores of ≤-2 or ≥2. Fourteen women were included in the analyses. A total of 151 genes with a significant fold-change were identified. In the CON group, a less-pronounced effect was observed. Strength training altered 23 pathways in the LPS-stimulated PBMCs, none of which overlapped between the IST and SET groups. A balanced exercise program that includes both IST and SET could beneficially adapt the immune responses in older adults by inducing alterations in the inflammatory stress response of PBMCs through different genes and pathways.

Exercise to Prevent Accelerated Vascular Aging in People Living With HIV

Given advances in antiretroviral therapy, the mortality rate for HIV infection has dropped considerably over recent decades. However, people living with HIV (PLWH) experience longer life spans coupled with persistent immune activation despite viral suppression and potential toxicity from long-term antiretroviral therapy use. Consequently, PLWH face a cardiovascular disease (CVD) risk more than twice that of the general population, making it the leading cause of death among this group. Here, we briefly review the epidemiology of CVD in PLWH highlighting disparities at the intersections of sex and gender, age, race/ethnicity, and the contributions of social determinants of health and psychosocial stress to increased CVD risk among individuals with marginalized identities. We then overview the pathophysiology of HIV and discuss the primary factors implicated as contributors to CVD risk among PLWH on antiretroviral therapy. Subsequently, we highlight the functional evidence of premature vascular dysfunction as an early pathophysiological determinant of CVD risk among PLWH, discuss several mechanisms underlying premature vascular dysfunction in PLWH, and synthesize current research on the pathophysiological mechanisms underlying accelerated vascular aging in PLWH, focusing on immune activation, chronic inflammation, and oxidative stress. We consider understudied aspects such as HIV-related changes to the gut microbiome and psychosocial stress, which may serve as mechanisms through which exercise can abrogate accelerated vascular aging. Emphasizing the significance of exercise, we review various modalities and their impacts on vascular health, proposing a holistic approach to managing CVD risks in PLWH. The discussion extends to critical future study areas related to vascular aging, CVD, and the efficacy of exercise interventions, with a call for more inclusive research that considers the diversity of the PLWH population.

Metabolic pathways in immune senescence and inflammaging: Novel therapeutic strategy for chronic inflammatory lung diseases. An EAACI position paper from the Task Force for Immunopharmacology

The accumulation of senescent cells drives inflammaging and increases morbidity of chronic inflammatory lung diseases. Immune responses are built upon dynamic changes in cell metabolism that supply energy and substrates for cell proliferation, differentiation, and activation. Metabolic changes imposed by environmental stress and inflammation on immune cells and tissue microenvironment are thus chiefly involved in the pathophysiology of allergic and other immune-driven diseases. Altered cell metabolism is also a hallmark of cell senescence, a condition characterized by loss of proliferative activity in cells that remain metabolically active. Accelerated senescence can be triggered by acute or chronic stress and inflammatory responses. In contrast, replicative senescence occurs as part of the physiological aging process and has protective roles in cancer surveillance and wound healing. Importantly, cell senescence can also change or hamper response to diverse therapeutic treatments. Understanding the metabolic pathways of senescence in immune and structural cells is therefore critical to detect, prevent, or revert detrimental aspects of senescence-related immunopathology, by developing specific diagnostics and targeted therapies. In this paper, we review the main changes and metabolic alterations occurring in senescent immune cells (macrophages, B cells, T cells). Subsequently, we present the metabolic footprints described in translational studies in patients with chronic asthma and chronic obstructive pulmonary disease (COPD), and review the ongoing preclinical studies and clinical trials of therapeutic approaches aiming at targeting metabolic pathways to antagonize pathological senescence. Because this is a recently emerging field in allergy and clinical immunology, a better understanding of the metabolic profile of the complex landscape of cell senescence is needed. The progress achieved so far is already providing opportunities for new therapies, as well as for strategies aimed at disease prevention and supporting healthy aging.

Exercise-Mediated Protection against Air Pollution-Induced Immune Damage: Mechanisms, Challenges, and Future Directions

Air pollution, a serious risk factor for human health, can lead to immune damage and various diseases. Long-term exposure to air pollutants can trigger oxidative stress and inflammatory responses (the main sources of immune impairment) in the body. Exercise has been shown to modulate anti-inflammatory and antioxidant statuses, enhance immune cell activity, as well as protect against immune damage caused by air pollution. However, the underlying mechanisms involved in the protective effects of exercise on pollutant-induced damage and the safe threshold for exercise in polluted environments remain elusive. In contrast to the extensive research on the pathogenesis of air pollution and the preventive role of exercise in enhancing fitness, investigations into exercise resistance to injury caused by air pollution are still in their infancy. In this review, we analyze evidence from humans, animals, and cell experiments on the combined effects of exercise and air pollution on immune health outcomes, with an emphasis on oxidative stress, inflammatory responses, and immune cells. We also propose possible mechanisms and directions for future research on exercise resistance to pollutant-induced damage in the body. Furthermore, we suggest strengthening epidemiological studies at different population levels and investigations on immune cells to guide how to determine the safety thresholds for exercise in polluted environments.

The effect of physical exercise on anticancer immunity

Regular physical activity is associated with lower cancer incidence and mortality, as well as with a lower rate of tumour recurrence. The epidemiological evidence is supported by preclinical studies in animal models showing that regular exercise delays the progression of cancer, including highly aggressive malignancies. Although the mechanisms underlying the antitumorigenic effects of exercise remain to be defined, an improvement in cancer immunosurveillance is likely important, with different immune cell subtypes stimulated by exercise to infiltrate tumours. There is also evidence that immune cells from blood collected after an exercise bout could be used as adoptive cell therapy for cancer. In this Perspective, we address the importance of muscular activity for maintaining a healthy immune system and discuss the effects of a single bout of exercise (that is, 'acute' exercise) and those of 'regular' exercise (that is, repeated bouts) on anticancer immunity, including tumour infiltrates. We also address the postulated mechanisms and the clinical implications of this emerging area of research.

A Case Series Tries to Answer Whether Exercise Positively Influences Immunosenescence

The immune system, the defense mechanism of the body, mainly consists of lymphocytes. The three primary subtypes of lymphocytes are natural killer cells (NK cells), bone marrow-derived lymphocytes (B-lymphocytes), and thymus-derived lymphocytes (T-lymphocytes). T-lymphocytes are mostly composed of CD (cluster of differentiation) cells, such as CD4+ and CD8+ subsets of CD cells. Immunosenescence is the term for the steady decline of the immune system with aging. There are alterations in the composition of various types of lymphocytes, especially in CD4 and CD8 T cells. The elderly are more vulnerable to infections due to immunosenescence, which raises morbidity and mortality rates. Physical exercises are believed to have the potential to alter immunosenescence and produce positive changes in immune cell composition. The extent of exercise-induced immune function changes was different in research studies owing to the differences in protocols, methodologies, testing procedures, ages, and gender compositions. The impact of an eight-week balance-based exercise intervention on immune biomarkers is investigated in this case series. In this case series, two elderly women residing in an institutional setting were exposed to an eight-week-long balanced-based supervised exercise intervention. The immunological biomarkers CD45, CD3, CD4, and CD8 were the outcome variables that were assessed. Data on the outcome variables was gathered both before and after the intervention. Using flow cytometry and single-platform technology, immune biomarkers were analyzed. Following the intervention, there was a rise in the CD45, CD3, CD4, and CD8 cell counts relative to the baseline data. The biomarkers showed only slight and statistically non-significant improvements.

Clonal Kinetics and Single-Cell Transcriptional Profiles of T Cells Mobilized to Blood by Acute Exercise

PURPOSE

Acute exercise redistributes large numbers of memory T cells, which may contribute to enhanced immune surveillance in regular exercisers. It is not known, however, if acute exercise promotes a broad or oligoclonal T-cell receptor (TCR) repertoire or evokes transcriptomic changes in "exercise-responsive" T-cell clones.

METHODS

Healthy volunteers completed a graded bout of cycling exercise up to 80% V̇O 2max . DNA was extracted from peripheral blood mononuclear cells collected at rest, during exercise (EX), and 1 h after (+1H) exercise, and processed for deep TCR-β chain sequencing and tandem single-cell RNA sequencing.

RESULTS

The number of unique clones and unique rearrangements was decreased at EX compared with rest ( P < 0.01) and +1H ( P < 0.01). Productive clonality was increased compared with rest ( P < 0.05) and +1H ( P < 0.05), whereas Shannon's Index was decreased compared with rest ( P < 0.05) and +1H ( P < 0.05). The top 10 rearrangements in the repertoire were increased at EX compared with rest ( P < 0.05) and +1H ( P < 0.05). Cross-referencing TCR-β sequences with a public database (VDJdb) revealed that exercise increased the number of clones specific for the most prevalent motifs, including Epstein-Barr virus, cytomegalovirus, and influenza A. We identified 633 unique exercise-responsive T-cell clones that were mobilized and/or egressed in response to exercise. Among these clones, there was an upregulation in genes related to cell death, cytotoxicity, and activation ( P < 0.05).

CONCLUSIONS

Acute exercise promotes an oligoclonal T-cell repertoire by preferentially mobilizing the most dominant clones, several of which are specific to known viral antigens and display differentially expressed genes indicative of cytotoxicity, activation, and apoptosis.

The effects of exercise training for eight weeks on immune cell characteristics among breast cancer survivors

Methods

This study examined the effects of exercise training for 8 weeks on blood immune cell characteristics among 20 breast cancer survivors (age 56 ± 6 years, Body Mass Index 25.4 ± 3.0 kg m2) within two years of treatment. Participants were randomly allocated to a partly-supervised or a remotely-supported exercise group (n = 10 each). The partly supervised group undertook 2 supervised (laboratory-based treadmill walking and cycling) and 1 unsupervised session per week (outdoor walking) progressing from 35 to 50 min and 55% to 70% V˙O2max. The remotely-supported group received weekly exercise/outdoor walking targets (progressing from 105 to 150 min per week 55% to 70% V˙O2max) via weekly telephone calls discussing data from a fitness tracker. Immune cell counts were assessed using flow cytometry: CD4+ and CD8+ T cells (Naïve, NA; Central memory, CM; and Effector cells, EM and EMRA; using CD27/CD45RA), Stem cell-like memory T cells (TSCMs; using CD95/CD127), B cells (plasmablasts, memory, immature and naïve cells using CD19/CD27/CD38/CD10) and Natural Killer cells (effector and regulatory cells, using CD56/CD16). T cell function was assessed by unstimulated HLA-DR expression or interferon gamma (IFN-γ) production with Enzyme-linked ImmunoSpot assays following stimulation with virus or tumour-associated antigens.

Results

Total leukocyte counts, lymphocytes, monocytes and neutrophils did not change with training (p > 0.425). Most CD4+ and CD8+ T cell subtypes, including TSCMs, and B cell and NK cell subtypes did not change (p > 0.127). However, across groups combined, the CD4+ EMRA T cell count was lower after training (cells/µl: 18 ± 33 vs. 12 ± 22, p = 0.028) and these cells were less activated on a per cell basis (HLA-DR median fluorescence intensity: 463 ± 138 vs. 420 ± 77, p = 0.018). Furthermore, the partly-supervised group showed a significant decrease in the CD4+/CD8+ ratio (3.90 ± 2.98 vs. 2.54 ± 1.29, p = 0.006) and a significant increase of regulatory NK cells (cells/µl: 16 ± 8 vs. 21 ± 10, p = 0.011). T cell IFN-γ production did not change with exercise training (p > 0.515).

Discussion

In summary, most immune cell characteristics are relatively stable with 8 weeks of exercise training among breast cancer survivors. The lower counts and activation of CD4+ EMRA T cells, might reflect an anti-immunosenescence effect of exercise.

12-week combined strength and endurance exercise attenuates CD8+ T-cell differentiation and affects the kynurenine pathway in the elderly: a randomized controlled trial

BACKGROUND

Age-related accumulation of highly differentiated CD8⁺ effector memory re-expressing CD45RA (EMRA) T-cells and disruption of the kynurenine (KYN) pathway are associated with chronic inflammation and the development of insulin resistance. In this study the aim was to investigate the effects of 12-week combined strength and endurance exercise on CD8⁺ T-cell differentiation and KYN pathway metabolites. Ninety-six elderly subjects (f/m, aged 50-70) were randomized to a control (CON) or exercise (EX) group. The EX group completed combined strength and endurance training twice weekly for one hour each time at an intensity of 60% of the one-repetition maximum for strength exercises and a perceived exertion of 15/20 for endurance exercises. The EX group was also randomly subdivided into two groups with or without a concomitant balanced diet intervention in order to examine additional effects besides exercise alone. Before and after the intervention phase, the proportions of CD8⁺ T-cell subsets and levels of KYN pathway metabolites in peripheral blood were determined.

RESULTS

The CD8⁺ EMRA T-cell subsets increased in the CON group but remained almost unchanged in the EX group (p = .02). Plasma levels of kynurenic acid (KA) increased in the EX group and decreased in the CON group (p = .03). Concomitant nutritional intervention resulted in lower levels of quinolinic acid (QA) compared with exercise alone (p = .03). Overall, there was a slight increase in the QA/KA ratio in the CON group, whereas it decreased in the EX group (p > .05).

CONCLUSIONS

Combined strength and endurance training seems to be a suitable approach to attenuate CD8⁺ T-cell differentiation in the elderly and to redirect the KYN pathway towards KA. The clinical relevance of these effects needs further investigation.

Remotely Supervised Weight Loss and Exercise Training to Improve Rheumatoid Arthritis Cardiovascular Risk: Rationale and Design of the Supervised Weight Loss Plus Exercise Training-Rheumatoid Arthritis Trial

Patients with rheumatoid arthritis (RA) remain at an increased risk for cardiovascular disease (CVD) and mortality. RA CVD results from a combination of traditional risk factors and RA-related systemic inflammation. One hypothetical means of improving overall RA CVD risk is through reduction of excess body weight and increased physical activity. Together, weight loss and physical activity can improve traditional cardiometabolic health through fat mass loss, while also improving skeletal muscle health. Additionally, disease-related CVD risk may improve as both fat mass loss and exercise reduce systemic inflammation. To explore this hypothesis, 26 older persons with RA and overweight/obesity will be randomized to 16 weeks of a usual care control arm or to a remotely Supervised Weight Loss Plus Exercise Training (SWET) program. A caloric restriction diet (targeting 7% weight loss) will occur via a dietitian-led intervention, with weekly weigh-ins and group support sessions. Exercise training will consist of both aerobic training (150 minutes/week moderate-to-vigorous exercise) and resistance training (twice weekly). The SWET remote program will be delivered via a combination of video conference, the study YouTube channel, and study mobile applications. The primary cardiometabolic outcome is the metabolic syndrome Z score, calculated from blood pressure, waist circumference, high-density lipoprotein cholesterol, triglycerides, and glucose. RA-specific CVD risk will be assessed with measures of systemic inflammation, disease activity, patient-reported outcomes, and immune cell function. The SWET-RA trial will be the first to assess whether a remotely supervised, combined lifestyle intervention improves cardiometabolic health in an at-risk population of older individuals with RA and overweight/obesity.

Single-cell sequencing of immune cells after marathon and symptom-limited cardiopulmonary exercise

Vigorous-intensity leisure-time physical activity, such as marathon, has become increasingly popular, but its effect on immune functions and health is poorly understood. Here, we performed scRNA-seq analysis of peripheral blood mononuclear cells (PBMCs) after a bout of symptom-limited cardiopulmonary exercise (CPX) test or marathon. Time-series single-cell analysis revealed the detailed series of landscapes of immune cells in response to short and long vigorous-intensity activities. Reduction of effective T cells was observed with the cell migration and motility pathways enriched in circulation following marathon. Baseline values of PBMCs abundance were reached around 1 h after CPX and 24 h following marathon, but longer time was required for expression recovery of cytotoxicity genes. The ratio of effector/naive T cells was found to change uniformly among the participants and could serve as a better indicator for exercise intensity than the CD4+/CD8+ T cell ratio. Moreover, we identified time-dependent monocyte state transitions after marathon.

Train your T cells: How skeletal muscles and T cells keep each other fit during aging

Frailty and a failing immune system lead to significant morbidities in the final years of life and bring along a significant burden on healthcare systems. The good news is that regular exercise provides an effective countermeasure for losing muscle tissue when we age while supporting proper immune system functioning. For a long time, it was assumed that exercise-induced immune responses are predominantly mediated by myeloid cells, but it has become evident that they receive important help from T lymphocytes. Skeletal muscles and T cells interact, not only in muscle pathology but also during exercise. In this review article, we provide an overview of the most important aspects of T cell senescence and discuss how these are modulated by exercise. In addition, we describe how T cells are involved in muscle regeneration and growth. A better understanding of the complex interactions between myocytes and T cells throughout all stages of life provides important insights needed to design strategies that effectively combat the wave of age-related diseases the world is currently faced with.

The Effect of Aerobic Exercise and Low-Impact Pilates Workout on the Adaptive Immune System

Growing evidence indicates the pronounced effects of physical activity on immune functions, which may largely depend on the type of exercise, intensity, and duration. However, limited information is available regarding the effects of low-impact exercises, especially on the level of adaptive immune system. Our study aimed to investigate and compare the changes in a broad spectrum of lymphocyte subtypes after 14 weeks of aerobic-type total-body-shaping workouts (TBSW) and Pilates workouts (PW) among healthy individuals. We determined the percentages of peripheral natural killer cells and different T and B lymphocyte subtypes with flow cytometry. At the end of the exercise program, significant changes in naïve and memory lymphocyte ratios were observed in TBSW group. Percentages of naïve cytotoxic T (Tc) cells elevated, frequencies of memory Tc and T-helper cell subsets decreased, and distribution of naïve and memory B cells rearranged. Proportions of activated T cells also showed significant changes. Nonetheless, percentages of anti-inflammatory interleukin (IL)-10-producing regulatory type 1 cells and immunosuppressive CD4⁺CD127^lo/-CD25^bright T regulative cells decreased not only after TBSW but also after PW. Although weekly performed aerobic workouts may have a more pronounced impact on the adaptive immune system than low-impact exercises, both still affect immune regulation in healthy individuals.

Immunosenescence in atherosclerosis: A role for chronic viral infections

Immune system is a versatile and dynamic body organ which offers survival and endurance of human beings in their hostile living environment. However, similar to other cells, immune cells are hijacked by senescence. The ageing immune cells lose their beneficial functions but continue to produce inflammatory mediators which draw other immune and non-immune cells to the senescence loop. Immunosenescence has been shown to be associated with different pathological conditions and diseases, among which atherosclerosis has recently come to light. There are common drivers of both immunosenescence and atherosclerosis; e.g. inflammation, reactive oxygen species (ROS), chronic viral infections, genomic damage, oxidized-LDL, hypertension, cigarette smoke, hyperglycaemia, and mitochondrial failure. Chronic viral infections induce inflammaging, sustained cytokine signaling, ROS generation and DNA damage which are associated with atherogenesis. Accumulating evidence shows that several DNA and RNA viruses are stimulators of immunosenescence and atherosclerosis in an interrelated network. DNA viruses such as CMV, EBV and HBV upregulate p16, p21 and p53 senescence-associated molecules; induce inflammaging, metabolic reprogramming of infected cells, replicative senescence and telomere shortening. RNA viruses such as HCV and HIV induce ROS generation, DNA damage, induction of senescence-associated secretory phenotype (SASP), metabolic reprogramming of infected cells, G1 cell cycle arrest, telomere shortening, as well as epigenetic modifications of DNA and histones. The newly emerged SARS-CoV-2 virus is also a potent inducer of cytokine storm and SASP. The spike protein of SARS-CoV-2 promotes senescence phenotype in endothelial cells by augmenting p16, p21, senescence-associated β-galactosidase (SA-β-Gal) and adhesion molecules expression. The impact of SARS-CoV-2 mega-inflammation on atherogenesis, however, remains to be investigated. In this review we focus on the common processes in immunosenescence and atherogenesis caused by chronic viral infections and discuss the current knowledge on this topic.

An immunologist's guide to immunosenescence and its treatment

INTRODUCTION

: The ageing process causes several changes in the immune system, although immune ageing is strongly influenced by individual immunological history, as well as genetic and environmental factors leading to inter-individual variability.

AREAS COVERED

: Here, we focused on the biological and clinical meaning of immunosenescence. Data on SARS-CoV-2 and Yellow Fever vaccine have demonstrated the clinical relevance of immunosenescence, while inconsistent results, obtained from longitudinal studies aimed at looking for immune risk phenotypes, have revealed that the immunosenescence process is highly context-dependent. Large projects have allowed the delineation of the drivers of immune system variance, including genetic and environmental factors, sex, smoking, and co-habitation. Therefore, it is difficult to identify the interventions that can be envisaged to maintain or improve immune function in older people. That suggests that drug treatment of immunosenescence should require personalized intervention. Regarding this, we discussed the role of changes in lifestyle as a potential therapeutic approach.

EXPERT OPINION

: Our review points out that age is only part of the problem of immunosenescence. Everyone ages differently because he/she is unique in genetics and experience of life and this applies even more to the immune system (immunobiography). Finally, the present review shows how appreciable results in the modification of immunosenescence biomarkers can be achieved with lifestyle modification.

Effects of functional and combined training on subsets of memory T cells and functional fitness of postmenopausal women: A randomized controlled trial

This study investigated the effects of functional (FT) and combined (CT) training on memory T cells and functional fitness of postmenopausal women. 108 participants were randomly allocated to the control (CG), FT and CT groups. Functional fitness was assessed through physical tests similar to daily activities, such as dressing on and taking off a t-shirt (DTTS), 10-meter walking and countermovement jump. The CCR7 and CD45RA surface markers were used to characterize the memory T cells. Regarding the frequency of memory T cells, both training protocols reduced the percentage of CD4⁺ Terminally Differentiated Effector Memory T Cells Re-Expressing CD45RA (T_EMRA) (FT: -38.73 %, p = 0.0455; CT: -30.43 %, p = 0.0036) and CD8⁺ T_EMRA cells (FT: -22.24 %, p < 0.0013; CT: -13.13 %, p = 0.0051). Also, both FT and CT increased the percentage of central memory (T_CM) CD4⁺ (FT: +55.22 %, p = 0.0104; CT: +68.03 %, p = 0.0167) and CD8⁺ (FT: +142.00 %, p < 0.0001; CT: +83.76 %, p = 0.0001) T cells. Furthermore, FT and CT increased the percentages of CD8⁺ effector memory T cells (T_EM) (FT: +63.58 %, p < 0.0001; CT: +14.12 %, p = 0.0041). Regarding functional fitness, both training protocols reduced the time required to perform the DTTS (FT: -19.71 %, p < 0.0001; CT: -14.69 %, p < 0.0001) and 10-m walk tests (FT: -13.05 %, p < 0.0001; CT: -12.83 %, p < 0.0001), in addition to improving jumping ability (FT: +29.97 %, p < 0.0001; CT: +20.00 %, p < 0.0001), both compared to the pre-test or to the CG. Therefore, both FT and CT seem to be equally effective alternatives for promoting the reduction of CD4⁺ and CD8⁺ T_EMRA cells, increasing the frequency of T_CM and T_EM cells, and improving functional fitness of postmenopausal women.

Inclusion body myositis: The interplay between ageing, muscle degeneration and autoimmunity

Inclusion body myositis (IBM) is a slowly progressive muscle disease affecting ageing individuals. IBM presents with a distinctive pattern of weakness involving the quadriceps and finger flexor muscles, although other muscles including pharyngeal muscles become affected over time. Pathological hallmarks of IBM include autoimmune features, including endomysial infiltration by highly differentiated T cells, as well as degenerative features marked by intramyofibre protein aggregates organised into inclusion bodies. Despite some progress in understanding the cellular pathways involved in IBM, it remains untreatable, and the progression of the disease leads to progressive weakness, disability, wheelchair dependency and loss of independence. Therefore, there is an urgent need to improve our understanding of the underlying mechanisms and pathways involved in this disease to identify new treatment targets. Here, we discuss the current understanding of aetiopathogenesis, the interrelationship between autoimmunity and degeneration, and how ageing is a major influencer of both these features.

T-cells in response to acute cardiorespiratory or resistance exercise in physically active or physically inactive older adults: A randomized crossover study

T-cells often undergo age-related changes, but regular exercise training may offset these age-related changes. However, the majority of literature is derived from cardiorespiratory exercise studies. The purpose of this study was to examine the effects of acute cardiorespiratory exercise and acute resistance exercise on the T-cell response among physically active older adults (PA) compared to physically inactive older adults (PI).

METHODS

Twenty-four healthy older adults (PA n=12; PI n=12; mean ± SD; age (yrs) PA 62 ± 5, PI 64 ± 5; BMI (kg/m²) PA 23.9 ± 3.0, PI 25.6 ± 3.5) completed one bout each of matched intensity cardiorespiratory exercise and resistance exercise in a randomized order. Blood samples drawn pre-exercise, post-exercise, and 1h post-exercise (recovery) were analyzed by flow cytometry for T-cells and T-cell subsets.

RESULTS

Resistance exercise mobilized more T-cell subsets in PI (10 of the measured types, including total T-cells; CD45RA+ CD62L+, CD45RA- CD62L+, CD45RA- CD62L-, and CD45RA+ CD62L- T-cells), whereas cardiorespiratory exercise mobilized more subsets in PA (CD45RA+ CD62L- and CD57+ CD45RA+ CD62L- CD4+ T-cells). Both cardiorespiratory exercise and resistance exercise elicited a significant (p<0.05) mobilization of highly-differentiated (CD45RA+ CD62L-; CD57+ CD45RA+ CD62L-) CD8+ T-cells into the circulation post-exercise in both PA and PI groups. Furthermore, cardiorespiratory exercise resulted in a decrease in the number of circulating Th17 cells post-exercise, while resistance exercise increased Th17 cell mobilization compared to the cardiorespiratory exercise response.

CONCLUSION

There are differences between cardiorespiratory exercise and resistance exercise on the immune responses of T-cells, particularly in PI individuals.

Exercise Training Improves Mitochondrial Bioenergetics of Natural Killer Cells

INTRODUCTION

Mitochondrial bioenergetics is critical for immune function in natural killer (NK) cell. Physical exercise modulates NK cell functionality, depending on the intensity and type of exercise. This study elucidates how interval and continuous exercise regimens affect the phenotypes and mitochondrial bioenergetics of NK cells.

METHODS

Sixty healthy sedentary males were randomly assigned to engage in either high-intensity interval training (HIIT, 3-min intervals at 80% and 40% maximal O2, n = 20; age, 22.2 yr; body mass index [BMI], 24.3 kg·m-2) or moderate-intensity continuous training (MICT, sustained 60% maximal O2, n = 20; age, 22.3 yr; BMI, 23.3 kg·m-2) for 30 min·d-1, 5 d·wk-1 for 6 wk or were assigned to a control group that did not receive exercise intervention (n = 20; age, 22.6 yr; BMI, 24.0 kg·m-2). Natural killer cell phenotypes, granule proteins, and mitochondrial oxidative stress/oxidative phosphorylation after graded exercise test (GXT) were measured before and after the various interventions.

RESULTS

Before the intervention, the GXT increased the mobilization of CD57+NK cells into the blood and elevated mitochondrial matrix oxidant burden (MOB) in NK cells, Following the 6 wk of interventions, both HIIT and MICT (i) diminished mobilization of CD57+NK cells into the blood and depressed mitochondrial MOB level in NK cells immediately after GXT, (ii) increased mitochondrial membrane potential and cellular perforin and granzyme B levels in NK cells, and (iii) enhanced the maximal and reserve O2 consumption rates and heightened bioenergetic health index in NK cells. In addition, HIIT increased maximal work rate than those of MICT.

CONCLUSIONS

Either HIIT or MICT increases the expressions of cytotoxic granule proteins and depresses mitochondrial MOB elevated by GXT, along with improving mitochondrial bioenergetic functionality in NK cells. Moreover, HIIT is superior to MICT in improving aerobic capacity.

The effect of resistance exercise on the immune cell function in humans: A systematic review

BACKGROUND

Resistance exercise is beneficial for the immune system, including decreased susceptibility to infections and improved effectiveness of vaccinations. This review aims to provide a systematic analysis of the literature regarding the impact of resistance exercise on immune cells in the blood circulation.

MATERIALS AND METHODS

The protocol of this review followed the PRISMA guidelines and registered in PROSPERO (ID: CRD42020157834). PubMed and Web-of-Science were systematically searched for relevant articles. Outcomes were divided into two categories: 1) inflammatory gene expression or secretion of inflammation-related cytokines and 2) other aspects such as cell migration, proliferation, apoptosis, phagocytosis, and redox status.

RESULTS

Thirty intervention studies were included in this review, of which 11 articles were randomized controlled trials and six non-randomized controlled trials. Although only resistance exercise interventions were included, there was a high heterogeneity regarding specific exercise modalities. The most frequently studied outcome measures were the gene and protein expression levels in peripheral blood mononuclear cells (PBMC). This review reveals that already one acute exercise bout activates the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway in PBMC. Although resistance exercise induces an acute cytosolic oxidative stress response, the antioxidant enzyme expression is improved after resistance training period. Natural killer cell activity increases in older but decreases in younger adults immediately after a resistance exercise bout. Moreover, resistance exercise improves neutrophil phagocytic activity. Finally, effects on lymphocyte proliferation remain unclear.

CONCLUSIONS

The results of this systematic review demonstrate that resistance exercise has beneficial effects on several aspects of immune cell function both in young and older individuals. Acute changes in immune cell function occur already after a single bout of resistance exercise. However, regular resistance training during several weeks seems necessary to obtain beneficial adaptations that can be related to better immunity and reduced inflammation. The effects documented in this review confirm the beneficial effects of resistance exercise in young as well as older persons on the immune cell function.

Reframing How Physical Activity Reduces The Incidence of Clinically-Diagnosed Cancers: Appraising Exercise-Induced Immuno-Modulation As An Integral Mechanism

Undertaking a high volume of physical activity is associated with reduced risk of a broad range of clinically diagnosed cancers. These findings, which imply that physical activity induces physiological changes that avert or suppress neoplastic activity, are supported by preclinical intervention studies in rodents demonstrating that structured regular exercise commonly represses tumour growth. In Part 1 of this review, we summarise epidemiology and preclinical evidence linking physical activity or regular structured exercise with reduced cancer risk or tumour growth. Despite abundant evidence that physical activity commonly exerts anti-cancer effects, the mechanism(s)-of-action responsible for these beneficial outcomes is undefined and remains subject to ongoing speculation. In Part 2, we outline why altered immune regulation from physical activity - specifically to T cells - is likely an integral mechanism. We do this by first explaining how physical activity appears to modulate the cancer immunoediting process. In doing so, we highlight that augmented elimination of immunogenic cancer cells predominantly leads to the containment of cancers in a 'precancerous' or 'covert' equilibrium state, thus reducing the incidence of clinically diagnosed cancers among physically active individuals. In seeking to understand how physical activity might augment T cell function to avert cancer outgrowth, in Part 3 we appraise how physical activity affects the determinants of a successful T cell response against immunogenic cancer cells. Using the cancer immunogram as a basis for this evaluation, we assess the effects of physical activity on: (i) general T cell status in blood, (ii) T cell infiltration to tissues, (iii) presence of immune checkpoints associated with T cell exhaustion and anergy, (iv) presence of inflammatory inhibitors of T cells and (v) presence of metabolic inhibitors of T cells. The extent to which physical activity alters these determinants to reduce the risk of clinically diagnosed cancers - and whether physical activity changes these determinants in an interconnected or unrelated manner - is unresolved. Accordingly, we analyse how physical activity might alter each determinant, and we show how these changes may interconnect to explain how physical activity alters T cell regulation to prevent cancer outgrowth.

Salutary effects of moderate but not high intensity aerobic exercise training on the frequency of peripheral T-cells associated with immunosenescence in older women at high risk of breast cancer: a randomized controlled trial

Background

Immunosenescence is described as age-associated changes within the immune system that are responsible for decreased immunity and increased cancer risk. Physically active individuals have fewer ‘senescent’ and more naïve T-cells compared to their sedentary counterparts, but it is not known if exercise training can rejuvenate ‘older looking’ T-cell profiles. We determined the effects of 12-weeks supervised exercise training on the frequency of T-cell subtypes in peripheral blood and their relationships with circulating levels of the muscle-derived cytokines (i.e. ‘myokines’) IL-6, IL-7, IL-15 and osteonectin in older women at high risk of breast cancer. The intervention involved 3 sessions/week of either high intensity interval exercise (HIIT) or moderate intensity continuous exercise (MICT) and were compared to an untrained control (UC) group.

Results

HIIT decreased total granulocytes, CD4+ T-cells, CD4+ naïve T-cells, CD4+ recent thymic emigrants (RTE) and the CD4:CD8 ratio after training, whereas MICT increased total lymphocytes and CD8 effector memory (EM) T-cells. The change in total T-cells, CD4+ naïve T-cells, CD4+ central memory (CM) T-cells and CD4+ RTE was elevated after MICT compared to HIIT. Changes in \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \dot{\mathrm{V}}{\mathrm{O}}_{2\max } $$\end{document}V˙O2max after training, regardless of exercise prescription, was inversely related to the change in highly differentiated CD8+ EMRA T-cells and positively related to changes in β2-adrenergic receptor (β2-AR) expression on CM CD4+ and CM CD8+ T-cells. Plasma myokine levels did not change significantly among the groups after training, but individual changes in IL-7 were positively related to changes in the number of β2-AR expressing CD4 naïve T cells in both exercise groups but not controls. Further, CD4 T-cells and CD4 naive T-cells were negatively related to changes in IL-6 and osteonectin after HIIT but not MICT, whereas CD8 EMRA T-cells were inversely related to changes in IL-15 after MICT but not HIIT.

Conclusions

Aerobic exercise training alters the frequency of peripheral T-cells associated with immunosenescence in middle aged/older women at high risk of breast cancer, with HIIT (pro-senescent) and MICT (anti-senescent) evoking divergent effects. Identifying the underlying mechanisms and establishing whether exercise-induced changes in peripheral T-cell numbers can alter the risk of developing breast cancer warrants investigation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12979-022-00266-z.

Protective Effects of Exercise Become Especially Important for the Aging Immune System in The Covid-19 Era

Aging is a complex, multietiological process and a major risk factor for most non-genetic, chronic diseases including geriatric syndromes that negatively affect healthspan and longevity. In the scenario of "healthy or good aging", especially during the COVID-19 era, the proper implementation of exercise as "adjuvant" or "polypill" to improve disease-related symptoms and comorbidities in the general population is a top priority. However, there is still a gap concerning studies analyzing influence of exercise training to immune system in older people. Therefore, the aim of this review is to provide a brief summary of well-established findings in exercise immunology and immunogerontology, but with a focus on the main exercise-induced mechanisms associated with aging of the immune system (immunosenescence). The scientific data strongly supports the notion that regular exercise as a low-cost and non-pharmacological treatment approach, when adjusted on an individual basis in elderly, induce multiple rejuvenating mechanisms: (1) affects the telomere-length dynamics (a "telo-protective" effect), (2) promote short- and long-term anti-inflammatory effects (via e.g., triggering the anti-inflammatory phenotype), 3) stimulates the adaptive immune system (e.g., helps to offset diminished adaptive responses) and in parallel inhibits the accelerated immunosenescence process, (4) increases post-vaccination immune responses, and (5) possibly extends both healthspan and lifespan.

Aging-associated immune system changes in multiple myeloma: The dark side of the moon

Multiple myeloma (MM) is a disease of the elderly. Changes that occur in the immune system with aging, also known as immunosenescence, have been associated with decreased tumor immunosurveillance and are thought to contribute to the development of MM and other cancers in the elderly. Once MM establishes itself in the bone marrow, immunosenescence related changes have been observed in the immune tumor microenvironment (iTME) and are driven by the malignant cells. The efficacy of novel immunotherapies used to treat MM has been blunted by detrimental iTME changes that occur at later disease stages and are, to some extent, driven by prior therapies. In this review, we discuss general changes that occur in the immune system with aging as well as our current knowledge of immunosenescence in MM. We discuss the differences and overlap between T cell senescence and exhaustion as well as potential methods to prevent or reverse immunosenescence. We focus predominantly on T cell immunosenescence which has been better evaluated in this disease and is more pertinent to novel MM immunotherapies. Our lack of understanding of the drivers of immunosenescence at each stage of the disease, from precursor stages to heavily pretreated MM, represents a major barrier to improving the efficacy of novel and existing therapies.

Better Response to Influenza Virus Vaccination in Physically Trained Older Adults Is Associated With Reductions of Cytomegalovirus-Specific Immunoglobulins as Well as Improvements in the Inflammatory and CD8+ T-Cell Profiles

Chronic cytomegalovirus (CMV) infection is a trigger factor for the development of immunosenescence and negatively impacts the immune response to influenza virus vaccination (IVV) in older adults. However, the role of physical exercise training in this context is unknown. Thus, the aim of this study was to investigate whether the regular practice of combined exercise training can improve the specific antibody response to IVV in CMV-seropositive older adults. Eighty older adults were distributed into two groups-non-practitioners (NP, n = 31, age = 74.06 ± 6.4 years) and practitioners of combined exercise training (CET, n = 49, age = 71.7 ± 5.8 years)-for at least 12 months. Both volunteer groups were submitted to IVV and blood samples were collected before (pre) and 30 days after (post) the vaccination. Concerning the specific antibody response to IVV, higher serum levels of specific immunoglobulin A (IgA) were found in the CET group post- than pre-vaccination (p < 0.01), whereas higher levels of specific immunoglobulin M (IgM) were observed both in the NP (p < 0.05) and CET (p < 0.001) groups post-vaccination as compared to the pre-vaccination values. Serum levels of specific immunoglobulin G (IgG) for IVV and CMV, as well as interleukin 6 (IL-6) and IL-10, were similar between the time points evaluated. However, the IL-10/IL-6 ratio post-vaccination was higher (p < 0.05) in the CET group than that before vaccination. Negative correlations were observed between the specific IgG levels for IVV and CMV only in the CET group, both pre- and post-vaccination. In addition, negative correlations were found between IL-10 and specific IgG for CMV in all volunteer groups pre- and post-vaccination, whereas a positive correlation between IL-10 and specific-IgG for IVV pre- and post-vaccination was observed in the CET group. In addition, with the hemagglutination inhibition (HAI) assay, it was found that 32.2% of the NP group and 32.6% of the CET group were responders to IVV and displayed reductions in the CMV serostatus (p < 0.05 and p < 0.001, respectively) and increases in naive and effector CD8+ T cells post-vaccination (p < 0.01). However, only the responders from the CET group showed significant reductions in the ratio of effector to naive CD8+ T cells (p < 0.05) and increased IL-10 levels post-vaccination (p < 0.001). In summary, this study demonstrates that the improvement in the response to IVV in CMV-seropositive older adults was related to an anti-inflammatory status and enhancement of naive CD8+ T cells, particularly associated with regular practice of CET.

Exercise and adrenergic regulation of immunity

Exercise training has a profound impact on immunity, exerting a multitude of positive effects in indications such as immunosenescence, cancer, viral infections and inflammatory diseases. The immune, endocrine and central nervous systems work in a highly synergistic manner and it has become apparent that catecholamine signaling through leukocyte β-adrenergic receptors (β-ARs) is a key mechanism by which exercise mediates improvements in immune function to help mitigate numerous disease conditions. Central to this is the preferential mobilization and redistribution of effector lymphocytes with potent anti-viral and anti-tumor activity, their interaction with muscle-derived cytokines, and the effects of catecholamine signaling on mitochondrial biogenesis, immunometabolism and the resulting inflammatory response. Here, we review the impact of acute and chronic exercise on adrenergic regulation of immunity in the context of aging, cancer, viral infections and inflammatory disease. We also put forth our contention that exercise interventions designed to improve immunity, prevent disease and reduce inflammation should consider the catecholamine-AR signaling axis as a therapeutic target and ask whether or not the adrenergic signaling machinery can be 'trained' to improve immune responses to stress, disease or during the normal physiological process of aging. Finally, we discuss potential strategies to augment leukocyte catecholamine signaling to boost the effects of exercise on immunity in individuals with desensitized β-ARs or limited exercise tolerance.

Effect of Resistance Training With Total and Partial Blood Flow Restriction on Biomarkers of Oxidative Stress and Apoptosis in Untrained Men

Introduction: The characterization of immune and oxidative stress responses to acute and chronic exercise training is important because it may aid in the safety and dose–response prescription of resistance training (RT) in many populations.

Purpose: The present study compared changes in acute oxidative stress and markers of apoptosis in immune cells before and after 8 weeks of low-load RT with total or partial blood flow restriction (BFR) versus high-load traditional RT.

Methods: Twenty-seven untrained men were randomly divided into three groups: traditional RT [75% one-repetition maximum (1-RM)], RT with partial (20% 1-RM), and total BFR (20% 1-RM). Over an 8-week period, participants performed six sets of arm curls until failure with 90 seconds of recovery for 3 days/week. Blood samples were obtained before and after the first and last training sessions.

Results: Data indicated that all training groups showed similar increases in muscular strength (p < 0.001), reduction in mitochondrial membrane potential (MMP) after exercise in neutrophils (p < 0.001), and increase in caspase-3 activity after exercise (p < 0.001). Traditional RT and total BFR showed increased plasma lipid peroxidation (p < 0.001) and protein carbonyls (p < 0.001) and lower levels of reduced glutathione (GSH) (p < 0.001) after exercise. No change was observed in oxidative stress biomarkers in response to partial BFR (p > 0.05).

Conclusion: Data show that RT with partial BFR can increase muscular strength but still does not augment biomarkers of oxidative stress in untrained men. In addition, RT with total BFR promoted similar responses of oxidative stress and markers of immune cell apoptosis versus traditional RT.

Influence of Exercise on Exhausted and Senescent T Cells: A Systematic Review

The impaired effector function of exhausted and senescent T cells is implicated in cancer progression and inadequate vaccine responses. Exercise has been shown to improve cancer therapy and vaccine efficacy, most likely by improving immune function. However, given inconsistent terminology and definitions, the interactions between exercise and exhausted and senescent T cells remain unclear. We therefore performed a systematic review to investigate the effect of exercise on senescent and exhausted CD8⁺ T cell populations clearly defined by protein surface markers. Thirty articles were included, with the majority (n = 24) reporting senescent T cell populations defined according to a variety of surface markers. Repeated exercise was shown to be beneficial through limiting the accumulation of senescent and exhausted CD8⁺ T cells. This outcome is likely related to exercise-induced preferential mobilization of senescent T cells promoting apoptosis in the peripheral blood compartment. Future studies need to determine the clinical relevance of this effect in cancer prevention and vaccine efficacy. Data regarding exercise and exhausted T cells are limited due to a lack of available high-quality studies. Future studies require the control of confounding variables such as sex and cytomegalovirus (CMV) status, and consistent definitions of exhausted and senescent T cell populations to improve comparisons between studies and interventions.

Functional and concurrent training do not impair immune function and improve functional fitness in postmenopausal women: A randomized controlled trial

PURPOSE

To evaluate the effects of functional and concurrent training on immune function and functional fitness in postmenopausal women.

MATERIALS AND METHODS

A randomized controlled trial was performed on 108 women aged 60 or older who were randomly assigned among the groups: control group (CG: n = 40; 63.88 ± 3.64 years); functional training (FT: n = 32; 63.88 ± 3.79 years); and concurrent training (CT: n = 36; 64.83 ± 4.00 years). Immune function was measured by the expression of the T-lymphocyte function-related surface markers (CD28 and CD57). Functional fitness was assessed using physical tests similar to daily activities, i.e., five times sit to stand, timed up and go, and gallon-jug shelf-transfer.

RESULTS

Regarding immune function, there was only a time effect, without between-group differences. Specifically, FT and CT show a reduction and increase in CD4⁺ and CD8⁺ T cells, respectively, without impairment in the subpopulations analyzed, while CG showed a reduction in naive T cells (CD8⁺CD28⁺). For functional fitness tests, there was a time × group interaction effect for all tests, the FT and CT were superior to the CG, with FT showing differences after the fourth week, while the CT showed this effect after the eighth week of intervention.

CONCLUSION

FT and CT do not impair immune function and similarly improve functional fitness in postmenopausal women.

CLINICAL TRIALS REGISTRY

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Exercising immune cells: The immunomodulatory role of exercise on atrial fibrillation

Exercise training is generally beneficial for cardiovascular health, improving stroke volume, cardiac output, and aerobic capacity. Despite these benefits, some evidence indicates that endurance training may increase the risk of atrial fibrillation (AF), particularly in highly trained individuals. Among multiple mechanisms, autonomic tone changes and atrial remodeling have been proposed as main contributors for exercise-induced AF. However, the contribution of local and systemic immunity is poorly understood in the development of atrial arrhythmogenic substrates. Here we aim to update the field of immunomodulation in the context of exercise and AF by compiling and reconciling the most recent evidence from preclinical and human studies and rationalize the applicability of "lone" AF terminology in athletes.

Immunometabolic responses according to physical fitness status and lifelong exercise during aging: New roads for exercise immunology

Molecules such as cytokines, energetic substrates, and hormones found in the immune cell environment, especially lymphocytes and monocytes, are crucial for directing energy metabolism. In turn, changes in energy metabolism occur in a synchronized manner with the activation of certain signaling pathways, thereby this crosstalk is responsible for determining the functionality of immune cells. The immunometabolism field has grown over time and that is becoming increasingly promising in several populations; here we discuss the mechanisms involved in sedentary and physically active middle-aged individuals and master athletes. In this context, this review shows that the physical activity status and lifelong exercise seems to be good strategies for the promotion of metabolic and functional adaptations in T lymphocytes and monocytes, counteracting inflammatory environments caused by expanded adipose tissue and sedentary behavior, as well as delaying the immunosenescence caused by aging.

Systematic review on the effects of physical exercise on cellular immunosenescence-related markers - An update

Immunosenescence is a remodeling of the immune system occurring with aging that leads to an increased susceptibility to auto-immunity, infections and reduced vaccination response. A growing consensus supports the view that physical exercise may counteract immunosenescence and improve the immune response. Unfortunately, evidence regarding the effects of exercise on markers of cellular immunosenescence lacked uniformity at the time of an extensive literature review in 2016. Moreover, exercise-induced effects in older adults were underrepresented compared to young adults or completely lacking, such as for senescent T-cells and apoptosis of T-lymphocytes. The aim of this systematic literature study was to collect and appraise newly available data regarding exercise-induced changes on immunosenescence-related markers of immune cells and compare this against data that was already available in 2016. Systematic reviewing of newly available data in the field of exercise immunology provides additional evidence for the effect of exercise on immunosenescence-related cellular markers. Importantly, this review provides evidence for the effect of long-term exercise on senescent T-lymphocytes in older adults. Additionally, newly retrieved evidence shows an acute exercise-induced mobilization of naïve and memory cells in older adults. In general, data regarding long-term exercise-induced effects in older adults remain scarce. Noteworthy was the high number of articles describing exercise-induced effects on regulatory T-cells. However exercise-induced effects on this cell type are still inconclusive as some articles reported an exercise-induced up- or downregulation, while others reported no effects at all. Numerous studies on Natural Killer cell counts did not provide uniformity among data that was already available. Recent data regarding dendritic cells mostly described an increase after exercise. Overall, our literature update highlights the major influence of the type and intensity of exercise on immunosenescence-related markers, especially in older adults.

Post-match recovery profile of leukocyte cell subsets among professional soccer players

This study assessed the impact of cumulative match time on the distribution of CD45+ cell subtests in the capillary blood of professional soccer players. Twenty-two males (aged 18-30 years) took part in the 36-week study. Participants playing up to 540 in cumulative match time and less than 30 min in each single match during the observation period formed the control group. White blood cell (WBC) phenotyping and creatine kinase (CK) plasma activity analyses were performed. Also, counts for WBC subsets were determined. No significant differences in the hematological parameters or lymphocyte and NK cell percentages were observed between the control and study groups. Changes in the T cell percentage were significant during weeks 11 and 30 and in Th and Tc cell percentages during weeks 2 and 26. Significant correlations were found between the cumulative match time and Th, NK, and B cell percentages; monocyte counts; and CK activity in the control group. However, for the study group, correlations were found between cumulative match time and Th, Tc, and B cell percentages; CK activity; and the CK ratio. Our study suggests that the distribution of CD45+ cells might be a useful tool for monitoring the immune status of professional soccer players.

The Effects of Physical Activity on the Aging of Circulating Immune Cells in Humans: A Systematic Review

Age-induced cellular senescence leads to a decline in efficacy of immune response and an increase in morbidity and mortality. Physical activity may be an intervention to slow down or reverse this process for elderly individuals or even delay it via enhanced activity over their lifespan. The aim of this systematic review was to analyze and discuss the current evidence of the effects of physical activity on senescence in leukocyte subpopulations. Two electronic databases (PubMed, Web of Science) were scanned in July 2020. Studies performing endurance or resistance exercise programs and investigating leukocytes of healthy, particularly elderly subjects were included. Nine human studies were identified, including a total of 440 participants, of which two studies examined different types of exercise training retrospectively, three conducted resistance exercise, three endurance exercise, and one endurance vs. resistance training. Results revealed that exercise training increased the naïve subsets of peripheral T-helper cells and cytotoxic T-cells, whereas the senescent and effector memory T-cells re-expresses CD45RA (TEMRA) subsets decreased. Moreover, the percentage of T-helper- compared to cytotoxic T-cells increased. The results suggest that physical activity reduces or slows down cellular immunosenescence. Endurance exercise seems to affect cellular senescence in a more positive way than resistance training. However, training contents and sex also influence senescent cells. Explicit mechanisms need to be clarified.

Impact of exercise on the immune system and outcomes in hematologic malignancies

Exercise is increasingly recognized as important to cancer care. The biology of how exercise improves outcomes is not well understood, however. Studies show that exercise favorably influences the immune system in healthy individuals (neutrophils, monocytes, natural killer cells, T cells, and a number of cytokines). Thus, exercise in patients with hematologic cancer could significantly improve immune function and tumor microenvironment. We performed a literature search and identified 7 studies examining exercise and the immune environment in hematologic malignancies. This review focuses on the role of exercise and physical activity on the immune system in hematologic malignancies and healthy adults.

Immune Response of Elite Enduro Racers to Laboratory and Racing Environments: The Influence of Training Impulse and Vibration

Introduction: Understanding the sport-specific immune response elicited during both training and competition is imperative to maximise athlete health and performance. Despite a growing population of professional enduro mountain bike athletes, little is known about the recovery of the immune system following enduro racing events. Methods: Nine international level elite enduro mountain bike athletes (age 24.3 ± 2.4 years, height 178.5 ± 8.7 cm, mass 76.5 ± 12.5 kg) completed a laboratory-based maximal exercise test (LAB) on a cycle ergometer and competed in an international mountain bike enduro race event (RACE). Blood samples were taken before, immediately after, and 1 h after LAB and before, 1 h after, and 17 h after RACE. Leukocyte subsets were enumerated using seven-colour flow cytometry. Lucia’s training impulse (LuTRIMP) and vibration exposure (VIB) were quantified during RACE. Results: Seven participants were included in the final analyses. There was a significant (p < 0.05) increase in neutrophil count alongside a reduction of cytotoxic lymphocyte cell subsets of both the innate (CD3⁻/CD56⁺ NK-cells and CD3⁻/CD56^dim NK-cells) and adaptive (CD8⁺/CD62L⁻/CD45RA⁻ T-cells and CD8⁺/CD27⁺/CD28⁻ T-cells) components of the immune system one hour after RACE. All cell counts returned to baseline values 17 h afterwards (p > 0.05). Cell subset redistribution from pre- to post-one-hour time points (%Δpre-post1h) in cell subsets with potent effector functions (Neutrophils, CD3⁻/CD56⁺ NK-cells, CD8⁺/CD62L⁻/CD45RA⁻ T-cells, CD8⁺/CD27⁺/CD28⁻ T-cells, and CD3⁻/CD56^dim/CD57⁻ NK-cells) was significantly greater at RACE than LAB (p < 0.05). VIB was shown to be a superior predictor of %Δpre-post1h CD4⁺ T-cells, CD4⁺ early T-cells, CD4⁺ naïve T-cells, and NK cells as compared with LuTRIMP on its own (ΔR² = 0.63 − 0.89, p < 0.05). Conclusions: The race event offers a greater challenge to the immune system than LAB, and potentially, whole body vibration is a key component of training load measurement in mountain bike applications.

Regular Exercise May Restore Certain Age-Related Alterations of Adaptive Immunity and Rebalance Immune Regulation

Age-related changes of the immune system lead to an increased morbidity and mortality due to enhanced vulnerability to infectious diseases and malignancies. Recent studies revealed the important effects of physical activity on immune functions, which may largely depend on the type of exercise, its intensity and duration. However, limited information is available regarding the immunological effects of sport activities in older ages. The aim of our study was to examine the changes in a wide spectrum of lymphocyte subtypes after regular workout among healthy elderly individuals. We enrolled 29 elderly women with sedentary lifestyle (mean age: 67.03 ± 3.74 years) to take part in a 6-week long functional conditioning gymnastic exercise program. The percentages of peripheral natural killer (NK), NKT cells, T and B lymphocyte subtypes (early-/late-activated T, naïve and memory T, cytotoxic T (Tc), T-helper (Th)1, Th2, Th17, T regulatory type 1 (Tr1), CD4⁺CD127^lo/-CD25^bright Treg, as well as naïve and memory B cells) were determined by flow cytometry. Evaluation of the changes in functional capability of Treg cells was based on in vitro functional assays. At the end of exercise program, in parallel with improvements in body composition and physical performance, significant changes in naïve and memory lymphocyte ratios were observed. Importantly, levels of naïve Tc cells elevated, ratios of effector memory Tc cells decreased and distribution of memory B cells rearranged as well. Additionally, proportions of late-activated HLA-DR⁺ T cells increased, while percentages of anti-inflammatory interleukin (IL)-10 producing Tr1 cells, as well as immunosuppressive CD4⁺CD127^lo/-CD25^bright Treg cells decreased following the exercise workout. Changes observed after the regular exercise program indicate an improvement in the age-related redistribution of certain naïve and memory cell proportions and a retuned immune regulation in older ages.

Cytomegalovirus and herpes simplex type 1 infections and immunological profile of community-dwelling older adults

Chronic infections, such as cytomegalovirus (CMV) and herpes simplex virus type 1 (HSV-1), contribute to the inflammation process among older adults and are associated with the immunosenescence process. The aim was to identify the immunological profile associated with CMV and HSV-1 infections among older adults. This is a cross-sectional study, carried out with 1492 participants from the Bambuí Cohort Study of Aging - Minas Gerais, Brazil. For analysis purposes, we considered the presence of immunoglobulin G (IgG) for CMV and HSV-1 in the participants' serum, assessed by the enzyme-linked immunosorbent assay (ELISA); outcomes were defined by titration above the median (>160 UR/mL for HSV-1 and >399.5 U/mL for CMV). In order to assess the immunological profile, the following biomarkers were considered: IL-1beta, IL-10, IL-12, TNF, CXCL8, CXCL9, CXCL10, CCL2, CCL5, IL-6 and CRP; the first four being categorized as detectable levels or not, and the others using the Classification and Regression Tree (CART) method. The analysis was adjusted for sociodemographic variables, health behaviors and health conditions. The seroprevalence of anti CMV and anti HSV-1 antibodies was 99.4% and 97.0%, respectively. Higher concentrations of CXCL8 and CCL5 chemokines were associated with lower antibody titers for CMV, and higher concentrations of CXCL9, IL-6 and CRP were associated with higher levels of antibodies to CMV. Moreover, intermediate levels of CXCL10 were also associated with higher levels of antibodies to CMV. In HSV-1 infection, intermediate levels of CXCL9, CCL5 and IL-6 were less likely to have higher antibody titers for this infection. On the other hand, higher levels of CXCL10 and CRP were positively associated with higher antibody titers for HSV-1. The results describe important immunological changes and reinforce the potential effect of CMV and HSV-1 on the immunosenescence process.

Acute exercise impacts AhR and PD-1 levels of CD8+ T-cells-Exploratory results from a randomized cross-over trial comparing endurance versus resistance exercise

PURPOSE

The programmed cell death protein 1 (PD-1) has become a promising target in cancer immunotherapy. PD-1 expression of CD8+ T-cells may be increased via the exploitation of aryl hydrocarbon receptor (AhR) signaling with kynurenine (KYN) as a ligand. Since exercise affects KYN metabolism, we exploratory investigated the influence of acute exercise bouts on AhR and PD-1 levels of CD8+ T-cells.

METHOD

In this study, 24 healthy males (age: 24.6 ± 3.9 years; weight 83.9 ± 10.5 kg; height: 182.4 ± 6.2 cm) completed a single bout of endurance (EE) and resistance exercise (RE) in a randomly assigned order on separate days. Blood samples were drawn before (t0), after (t1), and 1 h after (t2) both conditions. T-cell populations, the level of cytoplasmic AhR, and surface PD-1 were assessed by flow cytometry.

RESULTS

T-cell populations changed over time, indicated by an increase in the absolute numbers of CD3+ lymphocytes after EE (p < .001) and RE (p = .036) and in PD-1+ CD8+ T-cells after EE (p = .021). Proportions of T-cell populations changed only after EE (t0-t2: p = .029; t1-t2: p = .006). The level of cytoplasmic AhR decreased immediately after exercise in both exercise conditions (EE: p = .009; RE: p = .036). The level of surface PD-1 decreased 1 h after EE (p = .005).

CONCLUSION

We analyzed the level of surface PD-1 and cytoplasmic AhR following acute physical exercise for the first time. Especially EE was observed to impact both AhR and PD-1 levels, undermining its role as the AhR-PD-1 axis modulator. These results provide new insights into the impact of exercise on AhR-signaling, which could potentially be relevant for various chronic diseases.

Physical Exercise as a Multimodal Tool for COVID-19: Could It Be Used as a Preventive Strategy?

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or coronavirus disease 2019 (COVID-19) is a novel coronavirus not previously recognized in humans until late 2019. On 31 December 2019, a cluster of cases of pneumonia of unspecified etiology was reported to the World Health Organization in China. The availability of adequate SARS-CoV-2 drugs is also limited, and the efficacy and safety of these drugs for COVID-2019 pneumonia patients need to be assessed by further clinical trials. For these reasons, there is a need for other strategies against COVID-19 that are capable of prevention and treatment. Physical exercise has proven to be an effective therapy for most chronic diseases and microbial infections with preventive/therapeutic benefits, considering that exercise involves primary immunological mediators and/or anti-inflammatory properties. This review aimed to provide an insight into how the implementation of a physical exercise program against COVID-19 may be a useful complementary tool for prevention, which can also enhance recovery, improve quality of life, and provide immune protection against SARS-CoV-2 virus infection in the long term. In summary, physical exercise training exerts immunomodulatory effects, controls the viral gateway, modulates inflammation, stimulates nitric oxide synthesis pathways, and establishes control over oxidative stress.

The effects of β1 and β1+2 adrenergic receptor blockade on the exercise-induced mobilization and ex vivo expansion of virus-specific T cells: implications for cellular therapy and the anti-viral immune effects of exercise

The adoptive transfer of donor-derived virus-specific T cells (VSTs) is an effective treatment for infections following allogeneic hematopoietic cell transplantation. Acute exercise mobilizes effector lymphocytes and VSTs to the circulation and augments the ex vivo manufacture of VSTs. This study determined if β2 adrenergic receptor (AR) signaling precipitated the VST response to acute exercise. Healthy participants (n = 12) completed 30 min of steady-state cycling exercise after ingesting a placebo, a β1 + 2 AR antagonist (nadolol) or a β1 AR antagonist (bisoprolol). Circulating VSTs to cytomegalovirus (CMV), Epstein-Barr virus (EBV), and adenovirus (AdV) antigens were enumerated before and after exercise, and peripheral blood mononuclear cells were cultured with viral peptides for 8 days to expand multi-VSTs. Compared with placebo, nadolol blunted the exercise-induced mobilization of CMV-VSTs (Δ VSTs/100,000 CD3+ T cells = 93 ± 104 vs. 22 ± 91 for placebo and nadolol, respectively; p = 0.036), while bisoprolol did not, despite both drugs evoking similar reductions in exercising heart rate and blood pressure. Circulating AdV and EBV VSTs (VSTs/mL blood) only increased after exercise with placebo. Although not significant, nadolol partially mitigated exercise-induced increases in multi-VST expansion, particularly in participants that demonstrated an exercise-induced increase in VST expansion. We conclude that exercise-induced enhancements in VST mobilization and expansion are at least partially β2 AR mediated, thus highlighting a role for the β2 AR in targeted therapy for the augmentation of VST immune cell therapeutics in the allogeneic adoptive transfer setting. Moreover, long-term regular exercise may provide additional viral protection in the host through frequent β2 AR-dependent mobilization and redistribution of VSTs cumulated with each bout of exercise.

Strength Endurance Training but Not Intensive Strength Training Reduces Senescence-Prone T Cells in Peripheral Blood in Community-Dwelling Elderly Women

Aging is characterized by a progressive decline in immune function known as immunosenescence. Although the causes of immunosenescence are likely to be multifactorial, an age-associated accumulation of senescent T cells and decreased naive T-cell repertoire are key contributors to the phenomenon. On the other hand, there is a growing consensus that physical exercise may improve immune response in aging. However, the optimum training modality required to obtain beneficial adaptations in older subjects is lacking. Therefore, we aimed to investigate the effects of exercise modality on T-cell phenotypes in older women. A total of 100 women (aged ≥ 65 years) were randomized to either intensive strength training (80% of one-repetition maximum ), strength endurance training (40% one-repetition maximum), or control (stretching exercise) for 2-3 times per week during 6 weeks. The T-cell percentages and absolute counts were determined using flow cytometry and a hematology analyzer. C-reactive protein was measured using immunonephelometry. We report for the first time that 6 weeks of strength endurance training significantly decreased the basal percentage and absolute counts of senescence-prone T cells, which was positively related to the number of training sessions performed. Conceivably, training protocols with many repetitions-at a sufficiently high external resistance-might assist the reduction of senescence-prone T cells in older women.

Damage-Associated Molecular Patterns and Th-Cell-Related Cytokines Released after Progressive Effort

Inflammation-induced processes commence with the activation of signalling pathways at the cellular level, which mobilize inflammatory cells and stimulate the secretion of chemokines, cytokines, and damage-associated molecular pattern molecules (DAMPs). Physical effort stimulates inflammation, contributing to muscle repair and regeneration. We have examined the impact of different protocols of progressive-effort tests on T-cell DAMP levels, extracellular cleavage products (fibronectin and hyaluronan), and Th-cell-related cytokine levels among soccer players. Thirty male soccer players with a median age of 17 (16–22) years performed different defined protocols for progressive exercise until exhaustion: (1) YO-YO intermittent recovery test level 1 (YYRL1, n = 10); (2) maximal multistage 20 m shuttle run (Beep, n = 10); and mechanical treadmill (MT, n = 10); and (3) shuttle-run test (n = 10). Blood samples were taken three times as follows: at baseline, post effort, and in recovery. Significantly higher post-effort concentrations of IL-4, IL-6, IL-10, and IFN-γ were observed in the Beep group, IL-4 in the YYRL1 group, and IL-6 and IFN-γ in the MT group as compared with the baseline values. Recovery values were significantly higher for concentrations of IL-4, IL-10, and IFN-γ in the YYRL1 group, only for IFN-γ in the Beep group, and for IL-6, IL-10, and INF-γ in the MT group as compared with the baseline values. Post-effort concentrations of DEFβ2, Hsp27, Fn, and UA in the Beep group and Hsp27 and HA in the YYRL1 group were significantly higher as compared with the baseline values. It seems the performed efficiency test protocols caused a short-term imbalance in Th1/Th2 cytokine levels without giving common molecular patterns. The rapidity of these changes was apparently related to specific physical movements and the type of running surface.