Exercise-induced B cell mobilisation: Preliminary evidence for an influx of immature cells into the bloodstream

The effect of exercise and disease status on mobilization of anti-tumorigenic and pro-tumorigenic immune cells in women with breast cancer

Background

Mobilization of certain immune cells may improve the ability of the immune system to combat tumor cells, but the effect of acute exercise on mobilizing immune cells has been sparsely investigated in cancer patients. Therefore, we examined how acute exercise influences circulating immune cells in breast cancer patients.

Methods

Nineteen newly diagnosed breast cancer patients aged 36-68 performed 30 minutes of moderate-intensity exercise with a cycle ergometer. Blood samples were collected at various time points: at rest, at 15 (E15) and 30 minutes (E30) after onset of the exercise, and at 30 and 60 minutes post-exercise. We analyzed several immune cell subsets using flow cytometry.

Results

Acute exercise increased the number of total leukocytes, neutrophils, lymphocytes, monocytes, basophils, total T-cells, CD4+ T-cells, T helper (Th) 2-cells, Th 17-cells, CD8+ T-cells, CD4-CD8- T-cells, CD56+ natural killer (NK) cells, and CD14-CD16+ monocytes. Many of the changes were transient. Proportions of NK-cells and CD8+ T-cells increased, while the proportion of myeloid derived suppressor cells (MDSCs) reduced, and proportion of regulatory T-cells remained unchanged by exercise. Several associations were detected between cell mobilizations and disease state. For instance, tumor size correlated negatively with NK cell mobilization at E15, and progesterone receptor positivity correlated negatively with CD8+ T-cell mobilization.

Conclusion

The findings show that the proportions of CD8+ T-cells and NK cells increased and the proportion of MDSCs proportion decreased in breast cancer patients after 30-minute exercise, suggesting a change in the profile of circulating immune cells towards more cytotoxic/anti-tumorigenic. The mobilization of some immune cells also appears to be related to the disease state.

Impact of exercise on markers of B cell-related immunity: A systematic review

BACKGROUND

B cells represent a crucial component of adaptive immunity that ensures long-term protection from infection by generating pathogen-specific immunoglobulins. Exercise alters B cell counts and immunoglobulin levels, but evidence-based conclusions on potential benefits for adaptive immunity are lacking. This systematic review assessed current literatures on the impact of acute exercise and exercise training on B cells, immunoglobulins, and markers of secretory immunity in human biofluids.

METHODS

According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, MEDLINE, Web of Science, and Embase were searched on March 8, 2023. Non-randomized controlled trials and crossover trials investigating the impact of acute exercise or exercise training on B cell counts and proportions, immunoglobulin levels, salivary flow rate, or secretory immunoglobulin A secretion rate were included. Quality and reporting of exercise training studies were assessed using the Tool for the Assessment of Study Quality and reporting in Exercise. Study characteristics, outcome measures, and statistically significant changes were summarized tabularly.

RESULTS

Of the 67 eligible studies, 22 applied acute exercise and 45 applied exercise training. All included outcomes revealed significant alterations over time in acute exercise and exercise training context, but only a few investigations showed significant differences compared to control conditions. Secretory and plasma immunoglobulin A levels were most consistently increased in response to exercise training.

CONCLUSION

B cell-related outcomes are altered by acute exercise and exercise training, but evidence-based conclusions cannot be drawn with high confidence due to the large heterogeneity in populations and exercise modalities. Well-designed trials with large sample sizes are needed to clarify how exercise shapes B cell-related immunity.

A single bout of vigorous intensity exercise enhances the efficacy of rituximab against human chronic lymphocytic leukaemia B-cells ex vivo

Chronic lymphocytic leukaemia (CLL) is characterised by the clonal proliferation and accumulation of mature B-cells and is often treated with rituximab, an anti-CD20 monoclonal antibody immunotherapy. Rituximab often fails to induce stringent disease eradication, due in part to failure of antibody-dependent cellular cytotoxicity (ADCC) which relies on natural killer (NK)-cells binding to rituximab-bound CD20 on B-cells. CLL cells are diffusely spread across lymphoid and other bodily tissues, and ADCC resistance in survival niches may be due to several factors including low NK-cell frequency and a suppressive stromal environment that promotes CLL cell survival. It is well established that exercise bouts induce a transient relocation of NK-cells and B-cells into peripheral blood, which could be harnessed to enhance the efficacy of rituximab in CLL by relocating both target and effector cells together with rituximab in blood. In this pilot study, n = 20 patients with treatment-naïve CLL completed a bout of cycling 15 % above anaerobic threshold for ∼ 30-minutes, with blood samples collected pre-, immediately post-, and 1-hour post-exercise. Flow cytometry revealed that exercise evoked a 254 % increase in effector (CD3-CD56+CD16+) NK-cells in blood, and a 67 % increase in CD5+CD19+CD20+ CLL cells in blood (all p < 0.005). NK-cells were isolated from blood samples pre-, and immediately post-exercise and incubated with primary isolated CLL cells with or without the presence of rituximab to determine specific lysis using a calcein-release assay. Rituximab-mediated cell lysis increased by 129 % following exercise (p < 0.001). Direct NK-cell lysis of CLL cells - independent of rituximab - was unchanged following exercise (p = 0.25). We conclude that exercise improved the efficacy of rituximab-mediated ADCC against autologous CLL cells ex vivo and propose that exercise should be explored as a means of enhancing clinical responses in patients receiving anti-CD20 immunotherapy.

Immune consequences of exercise in hypoxia: A narrative review

Immune outcomes are key mediators of many health benefits of exercise and are determined by exercise type, dose (frequency/duration, intensity), and individual characteristics. Similarly, reduced availability of ambient oxygen (hypoxia) modulates immune functions depending on the hypoxic dose and the individual capacity to respond to hypoxia. How combined exercise and hypoxia (e.g., high-altitude training) sculpts immune responses is not well understood, although such combinations are becoming increasingly popular. Therefore, in this paper, we summarize the impact on immune responses of exercise and of hypoxia, both independently and together, with a focus on specialized cells in the innate and adaptive immune system. We review the regulation of the immune system by tissue oxygen levels and the overlapping and distinct immune responses related to exercise and hypoxia, then we discuss how they may be modulated by nutritional strategies. Mitochondrial, antioxidant, and anti-inflammatory mechanisms underlie many of the adaptations that can lead to improved cellular metabolism, resilience, and overall immune functions by regulating the survival, differentiation, activation, and migration of immune cells. This review shows that exercise and hypoxia can impair or complement/synergize with each other while regulating immune system functions. Appropriate acclimatization, training, and nutritional strategies can be used to avoid risks and tap into the synergistic potentials of the poorly studied immune consequences of exercising in a hypoxic state.

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.

The effects of short-term, progressive exercise training on disease activity in smouldering multiple myeloma and monoclonal gammopathy of undetermined significance: a single-arm pilot study

BACKGROUND

High levels of physical activity are associated with reduced risk of the blood cancer multiple myeloma (MM). MM is preceded by the asymptomatic stages of monoclonal gammopathy of undetermined significance (MGUS) and smouldering multiple myeloma (SMM) which are clinically managed by watchful waiting. A case study (N = 1) of a former elite athlete aged 44 years previously indicated that a multi-modal exercise programme reversed SMM disease activity. To build from this prior case study, the present pilot study firstly examined if short-term exercise training was feasible and safe for a group of MGUS and SMM patients, and secondly investigated the effects on MGUS/SMM disease activity.

METHODS

In this single-arm pilot study, N = 20 participants diagnosed with MGUS or SMM were allocated to receive a 16-week progressive exercise programme. Primary outcome measures were feasibility and safety. Secondary outcomes were pre- to post-exercise training changes to blood biomarkers of MGUS and SMM disease activity- monoclonal (M)-protein and free light chains (FLC)- plus cardiorespiratory and functional fitness, body composition, quality of life, blood immunophenotype, and blood biomarkers of inflammation.

RESULTS

Fifteen (3 MGUS and 12 SMM) participants completed the exercise programme. Adherence was 91 ± 11%. Compliance was 75 ± 25% overall, with a notable decline in compliance at intensities > 70% V̇O2PEAK. There were no serious adverse events. There were no changes to M-protein (0.0 ± 1.0 g/L, P =.903), involved FLC (+ 1.8 ± 16.8 mg/L, P =.839), or FLC difference (+ 0.2 ± 15.6 mg/L, P =.946) from pre- to post-exercise training. There were pre- to post-exercise training improvements to diastolic blood pressure (- 3 ± 5 mmHg, P =.033), sit-to-stand test performance (+ 5 ± 5 repetitions, P =.002), and energy/fatigue scores (+ 10 ± 15%, P =.026). Other secondary outcomes were unchanged.

CONCLUSIONS

A 16-week progressive exercise programme was feasible and safe, but did not reverse MGUS/SMM disease activity, contrasting a prior case study showing that five years of exercise training reversed SMM in a 44-year-old former athlete. Longer exercise interventions should be explored in a group of MGUS/SMM patients, with measurements of disease biomarkers, along with rates of disease progression (i.e., MGUS/SMM to MM).

REGISTRATION

https://www.isrctn.com/ISRCTN65527208 (14/05/2018).

Effect of intensive training on immune system cells in elite female weightlifters

OBJECTIVE

This study aimed to investigate the effects of intense weightlifting training on lymphocyte and natural killer cell subgroups, which are the major cells of the immune system, in elite female weightlifters.

METHODS

A total of 20 elite female weightlifters were evaluated using flow cytometry before training (pre-T), immediately after training (post-T), and after a 120-min rest period (rest-T).

RESULTS

Post-T and rest-T showed significant decreases in helper T (Th) and cytotoxic T compared with pre-T (p=0.045, p<0.001 and p=0.05, p<0.001, respectively). B and natural killer cells were higher in post-T and rest-T than in pre-T. The increase in B cells was significant in pre-T/rest-T (p<0.001) but not in pre-T/post-T (p=0.122). Intense training significantly increased natural killer cells in both post-T and rest-T (p<0.001). CD56bright and CD56dim natural killer cell subgroups were significantly lower in post-T and rest-T than in pre-T (p=0.005, p=0.006 and p<0.001, p=0.004, respectively).

CONCLUSION

This study shows that intense weightlifting alters peripheral lymphocyte and natural killer subgroup ratios, being the first investigation in this field.

Can Exercise Enhance the Efficacy of Checkpoint Inhibition by Modulating Anti-Tumor Immunity?

Immune checkpoint inhibition (ICI) has revolutionized cancer therapy. However, response to ICI is often limited to selected subsets of patients or not durable. Tumors that are non-responsive to checkpoint inhibition are characterized by low anti-tumoral immune cell infiltration and a highly immunosuppressive tumor microenvironment. Exercise is known to promote immune cell circulation and improve immunosurveillance. Results of recent studies indicate that physical activity can induce mobilization and redistribution of immune cells towards the tumor microenvironment (TME) and therefore enhance anti-tumor immunity. This suggests a favorable impact of exercise on the efficacy of ICI. Our review delivers insight into possible molecular mechanisms of the crosstalk between muscle, tumor, and immune cells. It summarizes current data on exercise-induced effects on anti-tumor immunity and ICI in mice and men. We consider preclinical and clinical study design challenges and discuss the role of cancer type, exercise frequency, intensity, time, and type (FITT) and immune sensitivity as critical factors for exercise-induced impact on cancer immunosurveillance.

Coping with the COVID-19 pandemic by strengthening immunity as a nonpharmaceutical intervention: A major public health challenge

Background and Aims

The global Coronavirus-2 outbreak has emerged as a significant threat to majority of individuals around the world. The most effective solution for addressing this viral outbreak is through vaccination. Simultaneously, the virus's mutation capabilities pose a potential risk to the effectiveness of both vaccines and, in certain instances, newly developed drugs. Conversely, the human body's immune system exhibits a robust ability to combat viral outbreaks with substantial confidence, as evidenced by the ratio of fatalities to affected individuals worldwide. Hence, an alternative strategy to mitigate this pandemic could involve enhancing the immune system's resilience.

Methods

The research objective of the review is to acquire a comprehensive understanding of the role of inflammation and immunity in COVID-19. The pertinent literature concerning immune system functions, the impact of inflammation against viruses like SARS-CoV-2, and the connection between nutritional interventions, inflammation, and immunity was systematically explored.

Results

Enhancing immune function involves mitigating the impact of key factors that negatively influence the immune response. Strengthening the immune system against emerging diseases can be achieved through nonpharmaceutical measures such as maintaining a balanced nutrition, engaging in regular exercise, ensuring adequate sleep, and managing stress.

Conclusion

This review aims to convey the significance of and provide recommendations for immune-strengthening strategies amidst the ongoing COVID-19 pandemic.

Harnessing the immunomodulatory effects of exercise to enhance the efficacy of monoclonal antibody therapies against B-cell haematological cancers: a narrative review

Therapeutic monoclonal antibodies (mAbs) are standard care for many B-cell haematological cancers. The modes of action for these mAbs include: induction of cancer cell lysis by activating Fcγ-receptors on innate immune cells; opsonising target cells for antibody-dependent cellular cytotoxicity or phagocytosis, and/or triggering the classical complement pathway; the simultaneous binding of cancer cells with T-cells to create an immune synapse and activate perforin-mediated T-cell cytotoxicity against cancer cells; blockade of immune checkpoints to facilitate T-cell cytotoxicity against immunogenic cancer cell clones; and direct delivery of cytotoxic agents via internalisation of mAbs by target cells. While treatment regimens comprising mAb therapy can lead to durable anti-cancer responses, disease relapse is common due to failure of mAb therapy to eradicate minimal residual disease. Factors that limit mAb efficacy include: suboptimal effector cell frequencies, overt immune exhaustion and/or immune anergy, and survival of diffusely spread tumour cells in different stromal niches. In this review, we discuss how immunomodulatory changes arising from exposure to structured bouts of acute exercise might improve mAb treatment efficacy by augmenting (i) antibody-dependent cellular cytotoxicity, (ii) antibody-dependent cellular phagocytosis, (iii) complement-dependent cytotoxicity, (iv) T-cell cytotoxicity, and (v) direct delivery of cytotoxic agents.

Impact of maximal exercise on immune cell mobilization and bioenergetics

Acute aerobic exercise increases the number and proportions of circulating peripheral blood mononuclear cells (PMBC) and can alter PBMC mitochondrial bioenergetics. In this study, we aimed to examine the impact of a maximal exercise bout on immune cell metabolism in collegiate swimmers. Eleven (7 M/4F) collegiate swimmers completed a maximal exercise test to measure anaerobic power and capacity. Pre- and postexercise PBMCs were isolated to measure the immune cell phenotypes and mitochondrial bioenergetics using flow cytometry and high-resolution respirometry. The maximal exercise bout increased circulating levels of PBMCs, particularly in central memory (KLRG1+/CD57-) and senescent (KLRG1+/CD57+) CD8+ T cells, whether measured as a % of PMBCs or as absolute concentrations (all p < 0.05). At the cellularlevel, the routine oxygen flow (IO₂ [pmol·s^-1 ·10⁶ PBMCs^-1 ]) increased following maximal exercise (p = 0.042); however, there were no effects of exercise on the IO₂ measured under the LEAK, oxidative phosphorylation (OXPHOS), or electron transfer (ET) capacities. There were exercise-induced increases in the tissue-level oxygen flow (IO_2-tissue [pmol·s^-1 ·mL blood^-1 ]) for all respiratory states (all p < 0.01), except for the LEAK state, after accounting for the mobilization of PBMCs. Future subtype-specific studies are needed to characterize further maximal exercise's true impact on immune cell bioenergetics.

The effect of acute exercise on circulating immune cells in newly diagnosed breast cancer patients

The role of exercise in cancer prevention and control is increasingly recognized, and based on preclinical studies, it is hypothesized that mobilization of leukocytes plays an important role in the anti-tumor effect. Thus, we examined how 10-min acute exercise modulates immune cells in newly diagnosed breast cancer patients. Blood samples were taken at rest, immediately after exercise and 30 min after exercise and phenotypic characterization of major leukocyte subsets was done using 9-color flow cytometry. Total leukocyte count increased by 29%, CD8⁺ T cell count by 34%, CD19⁺ B cell count by 18%, CD56⁺CD16⁺ NK cell count by 130%, and CD14⁺CD16⁺ monocyte count by 51% immediately after acute exercise. Mobilization of CD45⁺, CD8⁺, CD19⁺, and CD56⁺CD16⁺ cells correlated positively with exercising systolic blood pressure, heart rate percentage of age predicted maximal heart rate, rate pressure product, and mean arterial pressure. Our findings indicate that a single bout of acute exercise of only 10 min can cause leukocytosis in breast cancer patients. Mobilization of leukocytes appear to be directly related to the intensity of exercise. It is possible that the positive effect of exercise on oncologic outcome might be partly due to immune cell mobilization as documented in the present study.

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.

Novel strategies for cancer immunotherapy: counter-immunoediting therapy

The advent of immunotherapy has made an indelible mark on the field of cancer therapy, especially the application of immune checkpoint inhibitors in clinical practice. Although immunotherapy has proven its efficacy and safety in some tumors, many patients still have innate or acquired resistance to immunotherapy. The emergence of this phenomenon is closely related to the highly heterogeneous immune microenvironment formed by tumor cells after undergoing cancer immunoediting. The process of cancer immunoediting refers to the cooperative interaction between tumor cells and the immune system that involves three phases: elimination, equilibrium, and escape. During these phases, conflicting interactions between the immune system and tumor cells result in the formation of a complex immune microenvironment, which contributes to the acquisition of different levels of immunotherapy resistance in tumor cells. In this review, we summarize the characteristics of different phases of cancer immunoediting and the corresponding therapeutic tools, and we propose normalized therapeutic strategies based on immunophenotyping. The process of cancer immunoediting is retrograded through targeted interventions in different phases of cancer immunoediting, making immunotherapy in the context of precision therapy the most promising therapy to cure cancer.

The Impact of Exercise on Immunity, Metabolism, and Atherosclerosis

Physical exercise represents an effective preventive and therapeutic strategy beneficially modifying the course of multiple diseases. The protective mechanisms of exercise are manifold; primarily, they are elicited by alterations in metabolic and inflammatory pathways. Exercise intensity and duration strongly influence the provoked response. This narrative review aims to provide comprehensive up-to-date insights into the beneficial effects of physical exercise by illustrating the impact of moderate and vigorous exercise on innate and adaptive immunity. Specifically, we describe qualitative and quantitative changes in different leukocyte subsets while distinguishing between acute and chronic exercise effects. Further, we elaborate on how exercise modifies the progression of atherosclerosis, the leading cause of death worldwide, representing a prime example of a disease triggered by metabolic and inflammatory pathways. Here, we describe how exercise counteracts causal contributors and thereby improves outcomes. In addition, we identify gaps that still need to be addressed in the future.

Acute exercise mobilizes CD8+ cytotoxic T cells and NK cells in lymphoma patients

Background: Studies have shown that acute exercise can mobilize several leukocyte subpopulations in healthy individuals. Our aim was to investigate whether a 10-min acute exercise has an effect on immune cell proportions in lymphoma patients. Methods: This study included seven lymphoma patients referred to curative oncologic therapy. Three had Hodgkin and four non-Hodgkin lymphoma, one was female, and their mean age was 51. Patients underwent a 10-min acute exercise on a bicycle ergometer at moderate exercise intensity. Whole blood samples were taken at rest, immediately after exercise, and 30 min after exercise. Leukocyte subpopulation levels were determined using flow cytometry. Results: Proportions of total NK cells and CD56⁺CD16⁺ NK cells of total leukocytes increased immediately after exercise and decreased back to baseline at 30 min post-exercise. Proportion of CD8⁺ T cells of total T cells increased and proportion of CD4⁺ T cells of total T cells decreased immediately after exercise, and both returned to baseline at 30 min post-exercise. There was no change in the proportions of B cells, granulocytes, or monocytes. Exercising diastolic blood pressure correlated positively with changes in total NK cell and CD56⁺CD16⁺ NK cell proportions, and exercising mean arterial pressure correlated positively with change in CD56⁺CD16⁺ NK cell proportion. Conclusion: Our findings indicate that a single acute exercise bout of only 10 min can cause leukocytosis in lymphoma patients, particularly on cytotoxic T cells and NK cells, which are the most important immune cells fighting against cancer.

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.

Physical Activity as the Best Supportive Care in Cancer: The Clinician's and the Researcher's Perspectives

Multidisciplinary supportive care, integrating the dimensions of exercise alongside oncological treatments, is now regarded as a new paradigm to improve patient survival and quality of life. Its impact is important on the factors that control tumor development, such as the immune system, inflammation, tissue perfusion, hypoxia, insulin resistance, metabolism, glucocorticoid levels, and cachexia. An increasing amount of research has been published in the last years on the effects of physical activity within the framework of oncology, marking the appearance of a new medical field, commonly known as "exercise oncology". This emerging research field is trying to determine the biological mechanisms by which, aerobic exercise affects the incidence of cancer, the progression and/or the appearance of metastases. We propose an overview of the current state of the art physical exercise interventions in the management of cancer patients, including a pragmatic perspective with tips for routine practice. We then develop the emerging mechanistic views about physical exercise and their potential clinical applications. Moving toward a more personalized, integrated, patient-centered, and multidisciplinary management, by trying to understand the different interactions between the cancer and the host, as well as the impact of the disease and the treatments on the different organs, this seems to be the most promising method to improve the care of cancer patients.

Review on the Effect of Exercise Training on Immune Function

Exercise training is not only a necessary means to improve the level of exercise, but also an important means to improve the body's immunity. Different time, intensity, items, and forms of exercise training have different effects on the body's immune function. As a double-edged sword to improve the body's immune function, exercise training is a different reaction mechanism of different immune cells after exercise training. This paper combined with foreign scholars' studies on the immune function of the body of literature from different exercise intensity, different time, different sports, different movement forms, and different external environment such as angle of view for athletes body's immune cells and humoral immunity summarized the various indexes such as combing, in order to help academia, medicine, and sports. It provides enlightenment to the contemporary public on how to participate in sports training more healthily.

Why Physical Activity Should Be Considered in Clinical Trials for COVID-19 Vaccines: A Focus on Risk Groups

Since the World Health Organization declared the global COVID-19 state of emergency in early 2020, several vaccine candidates have emerged to control SARS-CoV-2, and some of them have been approved and implemented in vaccination campaigns worldwide. Although clinical trials for these vaccines have been carried out using highly controlled methods with accurate immunological tests, clinical questionnaires did not include questions concerning the physical activity profile among volunteers. It has been well established that physical activity plays a pivotal role in the immune response after vaccination, led by the activation of cytokines, antibodies, and cells. This concept should have been considered when evaluating the efficacy of COVID-19 vaccine candidates, particularly in elderly and obese people. Here, we discuss data from the literature providing strong evidence regarding the importance of analyzing physical activity parameters to improve the accuracy of clinical trials on assessing the efficacy of vaccine candidates.

Moderate Intensity Aerobic Exercise Potential Favorable Effect Against COVID-19: The Role of Renin-Angiotensin System and Immunomodulatory Effects

The coronavirus disease (COVID-19) pandemic is caused by a novel coronavirus (CoV) named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As the angiotensin converting enzyme 2 (ACE2) is the cellular receptor of SARS-CoV-2, it has a strong interaction with the renin angiotensin system (RAS). Experimental studies have shown that the higher levels of ACE2 or increasing ACE2/ACE1 ratio improve COVID-19 outcomes through lowering inflammation and death. Aerobic moderate intensity physical exercise fights off infections by two mechanisms, the inhibition of ACE/Ang II/AT1-R pathway and the stimulation of ACE2/Ang-(1-7)/MasR axis. Exercise can also activate the anti-inflammatory response so that it can be a potential therapeutic strategy against COVID-19. Here, we summarize and focus the relation among COVID-19, RAS, and immune system and describe the potential effect of aerobic moderate intensity physical exercise against CoV as a useful complementary tool for providing immune protection against SARS-CoV-2 virus infection, which is a novel intervention that requires further investigation.

Cytomegalovirus Infection Impairs the Mobilization of Tissue-Resident Innate Lymphoid Cells into the Peripheral Blood Compartment in Response to Acute Exercise

Circulating immune cell numbers and phenotypes are impacted by high-intensity acute bouts of exercise and infection history with the latent herpesviruses cytomegalovirus (CMV). In particular, CMV infection history impairs the exercise-induced mobilization of cytotoxic innate lymphoid cells 1 (ILC1) cells, also known as NK cells, in the blood. However, it remains unknown whether exercise and CMV infection modulate the mobilization of traditionally tissue-resident non-cytotoxic ILCs into the peripheral blood compartment. To address this question, 22 healthy individuals with or without CMV (20–35 years—45% CMV^pos) completed 30 min of cycling at 70% VO₂ max, and detailed phenotypic analysis of circulating ILCs was performed at rest and immediately post-exercise. We show for the first time that a bout of high-intensity exercise is associated with an influx of ILCs that are traditionally regarded as tissue-resident. In addition, this is the first study to highlight that latent CMV infection blunts the exercise-response of total ILCs and progenitor ILCs (ILCPs). These promising data suggest that acute exercise facilitates the circulation of certain ILC subsets, further advocating for the improvements in health seen with exercise by enhancing cellular mobilization and immunosurveillance, while also highlighting the indirect deleterious effects of CMV infection in healthy adults.

The Effects of Physical Exercise on Tumor Vasculature: Systematic Review and Meta-analysis

A wealth of evidence supports an association between physical exercise, decreased tumor growth rate, and reduced risk of cancer mortality. In this context, the tumor vascular microenvironment may play a key role in modulating tumor biologic behavior. The present systematic review and meta-analysis aimed to summarize the evidence regarding the effects of physical exercise on tumor vasculature in pre-clinical studies. We performed a computerized research on the PubMed, Scopus, and EBSCO databases to identify pre-clinical studies that evaluated the effect of physical exercise on tumor vascular outcomes. Mean differences were calculated through a random effects model. The present systematic review included 13 studies involving 373 animals. From these, 11 studies evaluated chronic intratumoral vascular adaptations and 2 studies assessed the acute intratumoral vascular adaptations to physical exercise. The chronic intratumoral vascular adaptations resulted in higher tumor microvessel density in 4 studies, increased tumor perfusion in 2 studies, and reduced intratumoral hypoxia in 3 studies. Quantitatively, regular physical exercise induced an increased tumor vascularization of 2.13 [1.07, 3.20] (p<0.0001). The acute intratumoral vascular adaptations included increased vascular conductance and reduced vascular resistance, which improved tumor perfusion and attenuated intratumoral hypoxia. In pre-clinical studies, physical exercise seems to improve tumor vascularization.

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.

Hormonal Dysregulation and Unbalanced Specialized Pro-Resolving Mediator Biosynthesis Contribute toward Impaired B Cell Outcomes in Obesity

Diet-induced obesity is associated with impaired B-cell-driven humoral immunity, which coincides with chronic inflammation and has consequences for responses to infections and vaccinations. Key nutritional, cellular, and molecular mechanisms by which obesity may impair aspects of humoral immunity such as B cell development, class switch recombination, and formation of long-lived antibody secreting cells are reviewed. A key theme to emerge is the central role of white adipose tissue on the formation and function of pro-inflammatory B cell subsets that exacerbate insulin resistance. The underlying role of select hormones such as leptin is highlighted, which may be driving the formation of pro-inflammatory B cells in the absence of antigen stimulation. This review also extensively covers the regulatory role of lipid metabolites such as prostaglandins and specialized pro-resolving mediators (SPMs) that are synthesized from polyunsaturated fatty acids. Notably, SPM biosynthesis is impaired in obesity and contributes toward impaired antibody production. Future directions for research, including avenues for therapeutic intervention, are included.

Coronavirus disease-2019: A tocsin to our aging, unfit, corpulent, and immunodeficient society

Acute and chronic respiratory illnesses cause widespread morbidity and mortality, and this class of illness now includes the novel coronavirus severe acute respiratory syndrome that is causing coronavirus disease-2019 (COVID-19). The world is experiencing a major demographic shift toward an older, obese, and physically inactive populace. Risk factor assessments based on pandemic data indicate that those at higher risk for severe illness from COVID-19 include older males, and people of all ages with obesity and related comorbidities such as hypertension and type 2 diabetes. Aging in and of itself leads to negative changes in innate and adaptive immunity, a process termed immunosenescence. Obesity causes systemic inflammation and adversely impacts immune function and host defense in a way that patterns immunosenescence. Two primary prevention strategies to reduce the risk for COVID-19 at both the community and individual levels include mitigation activities and the adoption of lifestyle practices consistent with good immune health. Animal and human studies support the idea that, in contrast to high exercise workloads, regular moderate-intensity physical activity improves immunosurveillance against pathogens and reduces morbidity and mortality from viral infection and respiratory illnesses including the common cold, pneumonia, and influenza. The odds are high that infectious disease pandemics spawned by novel pathogens will continue to inflict morbidity and mortality as the world's population becomes older and more obese. COVID-19 is indeed a wake-up call, a tocsin, to the world that primary prevention countermeasures focused on health behaviors and hygiene demand our full attention and support.

Plasma cells: You are what you eat

Plasma cells are terminally differentiated B lymphocytes that constitutively secrete antibodies. These antibodies can provide protection against pathogens, and their quantity and quality are the best clinical correlates of vaccine efficacy. As such, plasma cell lifespan is the primary determinant of the duration of humoral immunity. Yet dysregulation of plasma cell function can cause autoimmunity or multiple myeloma. The longevity of plasma cells is primarily dictated by nutrient uptake and non-transcriptionally regulated metabolic pathways. We have previously shown a positive effect of glucose uptake and catabolism on plasma cell longevity and function. In this review, we discuss these findings with an emphasis on nutrient uptake and its effects on respiratory capacity, lifespan, endoplasmic reticulum stress, and antibody secretion in plasma cells. We further discuss how some of these pathways may be dysregulated in multiple myeloma, potentially providing new therapeutic targets. Finally, we speculate on the connection between plasma cell intrinsic metabolism and systemic changes in nutrient availability and metabolic diseases.

Allostatic stress load and CMV serostatus impact immune response to maximal exercise in collegiate swimmers

Collegiate athletes are exposed to varying levels of academic and physical stressors, placing them at increased risk for stress-activated latent viral infections. However, the impact of allostatic stress load on the immune response to maximal exercise in athletes remains largely unknown. This study examined the effects of a 7-mo training period and cytomegalovirus (CMV) serostatus on immune cell response to high-intensity swim tests within a group of collegiate swimmers. Samples were collected from 15 National Collegiate Athletic Association Division I swimmers (9 men, 6 women: 19.87 ± 0.64 yr) before and after exhaustive in-pool swims at 2 time points (V₁: immediately post-season 1 and V₃: beginning of season 2). An additional off-season (V₂) time point was collected in a subset of 9 swimmers. Natural killer (NK) cell, B cell, and T cells were quantified by flow cytometry. Linear mixed models were used to determine the effects of exercise, time point, and CMV serostatus (α = 0.05). Resting senescent CD8+ T cells were higher in CMV-seropositive participants at V₃ (P = 0.005). CMV-seronegative participants had a decrease in resting senescent CD8+ T cells from V₁ to V₃ (P = 0.021). After acute exercise, CMV-seropositive participants had lower naïve CD8+ T cells (P < 0.001) and higher senescent CD8+ T cells (P < 0.001). Increased cumulative stress levels did not appear to affect B-cell and NK-cell compartments. Immune response to exercise was impacted by CMV serostatus and allostatic stress load. Young CMV-seropositive athletes exposed to elevated stressors should be monitored to determine long-term effects of training and academic stressors.NEW & NOTEWORTHY Allostatic stress load is associated with impaired immune response to maximal exercise in cytomegalovirus (CMV)-seropositive subjects but not in CMV-seronegative young healthy adults.

The compelling link between physical activity and the body's defense system

This review summarizes research discoveries within 4 areas of exercise immunology that have received the most attention from investigators: (1) acute and chronic effects of exercise on the immune system, (2) clinical benefits of the exercise-immune relationship, (3) nutritional influences on the immune response to exercise, and (4) the effect of exercise on immunosenescence. These scientific discoveries can be organized into distinctive time periods: 1900-1979, which focused on exercise-induced changes in basic immune cell counts and function; 1980-1989, during which seminal papers were published with evidence that heavy exertion was associated with transient immune dysfunction, elevated inflammatory biomarkers, and increased risk of upper respiratory tract infections; 1990-2009, when additional focus areas were added to the field of exercise immunology including the interactive effect of nutrition, effects on the aging immune system, and inflammatory cytokines; and 2010 to the present, when technological advances in mass spectrometry allowed system biology approaches (i.e., metabolomics, proteomics, lipidomics, and microbiome characterization) to be applied to exercise immunology studies. The future of exercise immunology will take advantage of these technologies to provide new insights on the interactions between exercise, nutrition, and immune function, with application down to the personalized level. Additionally, these methodologies will improve mechanistic understanding of how exercise-induced immune perturbations reduce the risk of common chronic diseases.

Changes to the Human Serum Proteome in Response to High Intensity Interval Exercise: A Sequential Top-Down Proteomic Analysis

Exercise has been shown to improve health status and prevent chronic diseases. In contrast, overtraining can lead to maladaptation and detrimental health outcomes. These outcomes appear to be mediated in part by released peptides and, potentially, alterations in protein abundances and their modified forms, termed proteoforms. Proteoform biomarkers that either predict the beneficial effects of exercise or indicate (mal)adaptation are yet to be elucidated. Thus, we assessed the influence of high-intensity interval exercise (HIIE) on the human serum proteome to identify novel exercise-regulated proteoforms. To this end, a top-down proteomics approach was used, whereby two-dimensional gel electrophoresis was used to resolve and differentially profile intact proteoforms, followed by protein identification via liquid chromatography-tandem mass spectrometry. Blood was collected from six young-adult healthy males, pre-exercise and 5 min and 1 h post-exercise. Exercise consisted of a maximal cycle ergometer test followed by 8 min × 1 min high-intensity intervals at 90% W max, with 1 min non-active recovery between intervals. Twenty resolved serum proteoforms changed significantly in abundance at 5 min and/or 1 h post-HIIE, including apolipoproteins, serpins (protease inhibitors), and immune system proteins, known to have broad anti-inflammatory and antioxidant effects, involvement in lipid clearance, and cardio-/neuro-protective effects. This initial screening for potential biomarkers indicates that a top-down analytical proteomic approach may prove useful in further characterizing the response to exercise and in understanding the molecular mechanisms that lead to health benefits, as well as identifying novel biomarkers for exercise (mal)adaptation.

Exercise as Adjunct Therapy in Cancer

Data from observational studies indicate that both physical activity as well as exercise (ie, structured physical activity) is associated with reductions in the risk of recurrence and cancer mortality after a diagnosis of certain forms of cancer. Emerging evidence from preclinical studies indicates that physical activity/exercise paradigms regulate intratumoral vascular maturity and perfusion, hypoxia, and metabolism and augments the antitumor immune response. Such responses may, in turn, enhance response to standard anticancer treatments. For instance, exercise improves efficacy of chemotherapeutic agents, and there is rationale to believe that it will also improve radiotherapy response. This review overviews the current preclinical as well as clinical evidence supporting exercise modulation of therapeutic response and postulated biological mechanisms underpinning such effects. We also examine the implications for tumor response to radiation, chemotherapy, and immunotherapy.

Aerobic exercise lengthens telomeres and reduces stress in family caregivers: A randomized controlled trial - Curt Richter Award Paper 2018

STUDY DESIGN

Family members caring for chronically ill relatives are typically sedentary, chronically stressed, and at high risk of disease. Observational reports suggest caregivers have accelerated cellular aging as indicated by shorter leukocyte telomere lengths. We performed a randomized controlled trial to examine the effect of aerobic exercise on changes in telomerase levels (primary outcome) and telomere lengths (secondary outcome) in inactive caregivers.

METHODS

68 female and male community dwelling dementia caregivers who reported high stress and physical inactivity were randomly assigned to a highly supervised aerobic exercise intervention vs. waitlist control group for 24 weeks. Average leukocyte telomere lengths and peripheral blood mononuclear cells' telomerase activity were measured pre- and post-intervention. All staff completing blood draws, fitness testing and bioassays were blinded to group assignment.

RESULTS

The intervention group completed approximately 40 min of aerobic exercise 3-5 times per week, verified by actigraphy. There was high (81%) adherence to 120 min/week of aerobic exercise. Groups did not significantly differ in telomerase activity changes across time, but had significant different telomere length changes across time (67.3 base pairs, 95%CI 3.1, 131.5). There were also significant reductions in body mass index and perceived stress and an increase in cardiorespiratory fitness (i.e., VO_2peak) in the exercising caregivers versus controls.

CONCLUSION

In the context of a highly controlled intervention, exercise can induce apparent telomere lengthening, though the mechanisms remain elusive. Our study underscores the importance of increasing participation in aerobic exercise to improve markers of health and attenuate cellular aging in high-risk samples.

B cell homeostasis is maintained during long-duration spaceflight

Long-duration spaceflights reportedly induce immune dysregulation, which is considered a risk to astronaut safety and mission success. Recent studies have examined the impact of spaceflight on markers of adaptive and innate immunity, but no study, to date, has comprehensively evaluated humoral immunity and serological markers of B cell function. The aim of this study was to characterize changes in B cell numbers and phenotypes, along with plasma Igs and polyclonal free light chains (FLCs)-near-"real-time" biomarkers of Ig synthesis-in response to an ~6-mo mission to the International Space Station (ISS). Whole-blood samples were collected before flight, during flight ("Early flight," "Mid-flight," and "Late flight"), immediately upon return, and during a recovery period (R + 18, R + 30/R + 33, and R + 60/R + 66) from 23 ISS crew members. B Cell counts and phenotypes were measured throughout the duration of the mission, along with total plasma Ig and FLC levels. There was no effect of spaceflight on the number and proportion of the different B cell subsets. There was no difference in kappa FLC between preflight samples and either in-flight or recovery samples ( P > 0.05), and only a marginal reduction was observed in lambda FLC levels upon return to Earth ( P < 0.05). Furthermore, IgG and IgM remained unchanged during and after spaceflight compared with preflight values ( P > 0.05). Of note, plasma IgA concentrations were elevated in-flight compared with baseline and recovery values ( P < 0.05). These results indicate that B cell homeostasis is maintained during long-duration spaceflight, advocating for potential in-flight vaccination as viable countermeasures against viral reactivation during exploration-class missions.

Reversing the immune ageing clock: lifestyle modifications and pharmacological interventions

It is widely accepted that ageing is accompanied by remodelling of the immune system, including reduced numbers of naïve T cells, increased senescent or exhausted T cells, compromise to monocyte, neutrophil and natural killer cell function and an increase in systemic inflammation. In combination these changes result in increased risk of infection, reduced immune memory, reduced immune tolerance and immune surveillance, with significant impacts upon health in old age. More recently it has become clear that the rate of decline in the immune system is malleable and can be influenced by environmental factors such as physical activity as well as pharmacological interventions. This review discusses briefly our current understanding of immunesenescence and then focuses on lifestyle interventions and therapeutic strategies that have been shown to restore immune functioning in aged individuals.

Acute aerobic exercise induces a preferential mobilisation of plasmacytoid dendritic cells into the peripheral blood in man

Dendritic cells (DCs) are important sentinel cells of the immune system responsible for presenting antigen to T cells. Exercise is known to cause an acute and transient increase in the frequency of DCs in the bloodstream in humans, yet there are contradictory findings in the literature regarding the phenotypic composition of DCs mobilised during exercise, which may have implications for immune regulation and health. Accordingly, we sought to investigate the composition of DC sub-populations mobilised in response to acute aerobic exercise. Nine healthy males (age, 21.9 ± 3.6 years; height, 177.8 ± 5.4 cm; body mass, 78.9 ± 10.8 kg; body mass index, 24.9 ± 3.3 kg·m²; V̇O_{2 MAX}, 41.5 ± 5.1 mL·kg·min^-1) cycled for 20 min at 80% V̇O_{2 MAX}. Blood was sampled at baseline, during the final minute of exercise and 30 min later. Using flow cytometry, total DCs were defined as Lineage- (CD3, CD19, CD20, CD14, CD56) HLA-DR+ and subsequently identified as plasmacytoid DCs (CD303+) and myeloid DCs (CD303-). Myeloid DCs were analysed for expression of CD1c and CD141 to yield four sub-populations; CD1c-CD141+; CD1c+CD141+; CD1c+CD141- and CD1c-CD141-. Expression of CD205 was also analysed on all DC sub-populations to identify DCs capable of recognising apoptotic and necrotic cells. Total DCs increased by 150% during exercise (F_(1,10) = 60; p < 0.05, η² = 0.9). Plasmacytoid DCs mobilised to a greater magnitude than myeloid DCs (195 ± 131% vs. 131 ± 100%; p < 0.05). Among myeloid DCs, CD1c-CD141- cells showed the largest exercise-induced mobilisation (167 ± 122%), with a stepwise pattern observed among the remaining sub-populations: CD1c+CD141- (79 ± 50%), followed by CD1c+CD141+ (44 ± 41%), with the smallest response shown by CD1c-CD141+ cells (23 ± 54%) (p < 0.05). Among myeloid DCs, CD205- cells were the most exercise responsive. All DC subsets returned to resting levels within 30 min of exercise cessation. These results show that there is a preferential mobilisation of plasmacytoid DCs during exercise. Given the functional repertoire of plasmacytoid DCs, which includes the production of interferons against viral and bacterial pathogens, these findings indicate that exercise may augment immune-surveillance by preferentially mobilising effector cells; these findings have general implications for the promotion of exercise for health, and specifically for the optimisation of DC harvest for cancer immunotherapy.

Debunking the Myth of Exercise-Induced Immune Suppression: Redefining the Impact of Exercise on Immunological Health Across the Lifespan

Epidemiological evidence indicates that regular physical activity and/or frequent structured exercise reduces the incidence of many chronic diseases in older age, including communicable diseases such as viral and bacterial infections, as well as non-communicable diseases such as cancer and chronic inflammatory disorders. Despite the apparent health benefits achieved by leading an active lifestyle, which imply that regular physical activity and frequent exercise enhance immune competency and regulation, the effect of a single bout of exercise on immune function remains a controversial topic. Indeed, to this day, it is perceived by many that a vigorous bout of exercise can temporarily suppress immune function. In the first part of this review, we deconstruct the key pillars which lay the foundation to this theory-referred to as the "open window" hypothesis-and highlight that: (i) limited reliable evidence exists to support the claim that vigorous exercise heightens risk of opportunistic infections; (ii) purported changes to mucosal immunity, namely salivary IgA levels, after exercise do not signpost a period of immune suppression; and (iii) the dramatic reductions to lymphocyte numbers and function 1-2 h after exercise reflects a transient and time-dependent redistribution of immune cells to peripheral tissues, resulting in a heightened state of immune surveillance and immune regulation, as opposed to immune suppression. In the second part of this review, we provide evidence that frequent exercise enhances-rather than suppresses-immune competency, and highlight key findings from human vaccination studies which show heightened responses to bacterial and viral antigens following bouts of exercise. Finally, in the third part of this review, we highlight that regular physical activity and frequent exercise might limit or delay aging of the immune system, providing further evidence that exercise is beneficial for immunological health. In summary, the over-arching aim of this review is to rebalance opinion over the perceived relationships between exercise and immune function. We emphasize that it is a misconception to label any form of acute exercise as immunosuppressive, and, instead, exercise most likely improves immune competency across the lifespan.