Exercise Immunology Review最新文献

Background: Several studies have reported that marathon runners have a higher risk of upper respiratory tract infections (URTI) post marathon than non-exercising controls. However, other studies did not find a higher risk of URTI in the same participants before and after a marathon, precluding a conclusive consensus. Besides the between-subjects effects, another important confounding factor in these results is the different pre and post follow-up time to track URTI.

Objectives: Identify by meta-analysis whether a marathon Running increases the risk of URTI, adjusting the follow-up time to track URTI.

Data sources: We searched for articles using MEDLINE (PubMed), Embase, Scopus, Web of Science, the Cochrane Library, and EBSCOhost, combining the marathon and respiratory infection descriptor synonyms, on 1st December 2022.

Eligibility criteria: The PICOS framework included human population, comparison between pre and post marathon running, of URTI symptoms (assessed from one to 4 weeks), in noncontrolled intervention studies.

Data synthesis: Because follow-up was longer before the marathon in many studies, we adjusted the number of subjects with infections before marathon to the equivalent post-marathon follow-up duration. There was 18% higher incidence of URTI post-marathon (OR 1.18 95%CI [1.05-1.33], p= 0.005) in a very consistent meta-analysis (I2 = 0%, p = 0.69), with no risk of publication bias (Egger test p-value = 0.82) for the 7 studies included. The main issues with quality of the studies were bias in measuring the outcome, bias in classification of intervention (participation in the marathon) and time-varying confounding (corrected for analysis), and therefore the quality of evidence was moderate (GRADE approach = 3).

Limitations: The need for follow-up time adjustment is a limitation, since the number of URTI recorded could be different if the original studies had used the same follow-up time pre and post marathon. The subjectivity of the URTI assessments is another limitation in this field.

Conclusions: There is an increased risk of URTI post marathon running and research on this topic to understand mechanisms might support runners to find efficient interventions to reduce this risk.

Protocol: Protocol registration on in the International Prospective Register of Systematic Reviews (PROSPERO): CRD42022380991.

Moderate exercise is effective for maintaining or improving overall health. However, excessive exercise that exhausts the adaptive reserve of the body or its ability to positively respond to training stimuli can induce tissue damage and dysfunction of multiple organs and systems. Tissue injury, inflammation, and oxidative stress are reportedly induced in the skeletal muscles, liver, and kidneys after exercise. However, the precise mechanisms underlying acute tissue injury after intense exercise have not yet been fully elucidated. Studies using various experimental models of acute tissue injury, other than intense exercise, have demonstrated infiltration of inflammatory cells, including neutrophils and macrophages. These cells infiltrate injured tissues and induce inflammatory and oxidative stress responses by producing inflammatory cytokines and reactive oxygen species, thereby exacerbating tissue injury. In addition to the activation of blood neutrophils and increase in their levels during and/or after prolonged or intense exercise, chemokines that contribute to leukocyte migration are released, facilitating the migration of neutrophils and monocytes into tissues. Therefore, neutrophils and macrophages, activated by exhaustive exercise, may infiltrate tissues and contribute to exhaustive exercise-induced tissue injury. Recently, the contributions of neutrophils and macrophages to various tissue injuries caused by exhaustive exercise have been reported. In this review, we summarize the involvement of neutrophils and monocytes/macrophages in exhaustive exercise-induced non-skeletal muscle tissue injury. In addition, we present novel data demonstrating the contribution of neutrophils and macrophages to exhaustive exercise-induced cardiac and pulmonary injuries. Our study findings and the evidence presented in this review suggest that neutrophils and macrophages may play pivotal roles in exhaustive exercise-induced tissue injuries.

Purpose: This study analyses the immune response of elite athletes after COVID-19 vaccination with double-dose mRNA and a single-dose vector vaccine.

Methods: Immunoglobulin G (IgG) antibody titers, neutralizing activity, CD4 and CD8 T-cells were examined in blood samples from 72 athletes before and after vaccination against COVID-19 (56 mRNA (BNT162b2 / mRNA-1273), 16 vector (Ad26.COV.2) vaccines). Side effects and training time loss was also recorded.

Results: Induction of IgG antibodies (mRNA : 5702 BAU/ml ; 4343 BAU/ml (hereafter: median), vector: 61 BAU/ml ; 52 BAU/ml, p<0.01), their neutralizing activity (99.7% ; 10.6%, p<0.01), and SARS-CoV-2 spike-specific CD4 T-cells (0.13% ; 0.05% ; p<0.01) after mRNA double-dose vaccines was significantly more pronounced than after a single-dose vector vaccine. SARS-CoV-2 spike-specific CD8 T-cell levels after a vector vaccine (0.15%) were significantly higher than after mRNA vaccines (0.02%; p<0.01). When athletes who had initially received the vector vaccine were boostered with an mRNA vaccine, IgG antibodies (to 3456 BAU/ml; p<0.01), neutralizing activity (to 100%; p<0.01), CD4 (to 0.13%; p<0.01) and CD8 T-cells (to 0.43%; p<0.01) significantly increased. When compared with dual-dose mRNA regimen, IgG antibody response was lower (p<0.01), the neutralizing activity (p<0.01) and CD8 T-cell (p<0.01) response higher and no significant difference in CD4 T-cell response (p=0.54) between the two regimens. Cumulative training loss (3 days) did not significantly differ between vaccination regimens (p=0.46).

Conclusion: mRNA and vector vaccines against SARSCoV-2 appear to induce different patterns of immune response in athletes. Lower immune induction after a single-shot vector vaccine was clearly optimized by a heterologous booster. Vaccine reactions were mild and short-lived.

Conventional chemotherapies can stimulate the immune system by increasing tumour antigenicity (e.g., neoantigen exposure to immune cells) and altering adjuvanticity in the tumour (e.g., danger associated molecular patterns and cytokines). These molecules promote the recruitment, activation, and maturation of dendritic cells, which in turn, prime and activate cytotoxic T cells against tumour cells. However, several factors can decrease the immunostimulatory efficacy of chemotherapeutic agents. These include reduced tumour cell antigenicity and adjuvanticity and compromised immune function at a local and systemic level. Findings from preclinical studies show that dietary restriction and exercise promote systemic changes that may help to restore immune system function through several mechanisms, including an enhanced infiltration and function of antitumoral immune cells and a decrease in immunosuppressive cells, leading to a reduction in tumour volume. In addition, dietary restriction and exercise training in mice have been shown to enhance the efficacy of chemotherapy. In human studies there is also emerging evidence that dietary restriction and exercise can impact the immune system towards a more antitumoral profile. In this review, we discuss the immunostimulatory effects of dietary restriction (caloric restriction and fasting) and exercise training in preclinical cancer models, and potential synergies with chemotherapy. We then review clinical studies assessing the effects of these interventions on immune-related endpoints and tumour responses. Finally, we propose that combining dietary restriction with exercise could be a promising strategy to increase chemotherapy efficacy.

Skin cancer has the highest incidence of all cancers, and their incidence are increasing in both melanoma and non-melanoma skin cancers. Alternative adjuvant treatment strategies appropriate for their management are needed. Modifiable lifestyle factors influence disease outcomes, either improving or worsening outcomes. Exercise is an example of a modifiable lifestyle factor, and can be prescribed as an adjuvant therapy in other cancer types to improve immune function and overall clinical outcomes. The initial aim of the review was to investigate the T-cell specific mechanisms of exercise which affect clinical/disease outcomes in skin cancer. Study quality was assessed by a modified Covidence quality assessment template with animal-model study specific criteria. A total of 10 articles were included; all articles were murine model studies investigating melanoma. Eight studies (n=8) employed a randomised controlled trial design, with two bio-informatics studies, and one study using human data which could solidify a link to human health. While the review focussed initially on T-cells, many studies reported significant changes in NK cells, and as they share the same haematopoietic lineage/ common lymphoid progenitor as T cells, the data was included in the analyses. Most studies indicated that exercise reduced melanoma tumour burden. Exercising prior to melanoma inoculation was most effective for delaying carcinogenesis and reducing tumour burden. Synergism was a topic identified in studies; PD-1/PD-L1 treatment, and exercise were not synergistic. Conversely, exercise and mental stimulation were synergistic, and the temperature at which exercise was conducted significantly reduced tumour burden. Several murine studies reported that exercise improved clinical outcomes in melanoma, and that long-term exercise was more effective in reducing tumour burden. Further studies are required to investigate this relationship in humans, and in other types of skin cancer.

Background: Both acute and chronic exercise have profound effects on systemic metabolism and the immune system. While acute exercise transiently disturbs energy homeostasis and elicits acute inflammation, exercise training improves systemic metabolic capacity, lowers basal inflammation, and reduces infection risk. Accordingly, accumulating evidence indicates links between systemic and immune cell metabolism and suggests that cellular metabolism may be an important way exercise influences immune function. Yet, no reviews have systematically surveyed the literature in this area.

Aims: The aims of this scoping review were to collect, summarize, and provide descriptive analysis of literature on the effects of acute exercise, chronic exercise, and physical fitness on peripheral leukocyte energy metabolism of human adults.

Methods: Reports were retrieved from the databases Pubmed, Scopus, and Embase and hierarchically filtered for eligibility. Eligible reports were those that implemented acute or chronic exercise interventions, or assessed physical fitness, in relation to the regulation or function of leukocyte energy metabolism in human adults. Data were charted from eligible reports by two independent reviewers, confirmed by conference, and organized for reporting.

Results & conclusion: Results suggest acute exercise can influence the regulation and function of leukocyte metabolism, with some similarities to what has been previously documented in skeletal muscle. Data also evidence that exercise training and/ or physical fitness alters cellular metabolic regulation and function. Improvements in markers of cell respiratory function or mitochondrial regulation were frequently observed following training or with greater fitness. However, notable gaps in the literature remain. These gaps include: the effects of acute exercise and exercise training on leukocyte glycolysis, the effects of resistance and concurrent exercise, and potential differences in the effects of exercise between immune cell types and subsets. Future research is encouraged to fill the latter gaps and further delineate how exercise influences the immune system and can be used to support overall health.

Macrophage accumulation in the adipose tissue and changes in their inflammatory phenotype is a hallmark of obesity-induced inflammation, notably forming inflammatory structures known as "crown-like structures (CLS)". Exercise can be a key strategy to improve inflammation-related complications, but it is crucial to consider that, although exercise generally exerts systemic and local anti-inflammatory effects, this depends on the basal inflammatory status and exercise modality. In this context, the "bioregulatory effect of exercise" implies to achieve the reduction or prevention of an excessive inflammatory response and also the preservation or stimulation of the innate response. In the present work, our aim was to evaluate the effect of regular exercise on adipose tissue inflammation in high-fat diet-induced obesity in mice, as reflected by macrophage infiltration and phenotype, and CLS formation, together with a potential role for the chemokine MCP-1 in this process. Results showed that obesity is associated with greater MCP-1 expression (p<0.05), macrophage accumulation (p<0.05), and CLS presence (p<0.001). Regular exercise reduced macrophage accumulation (p<0.05), MCP-1 expression (p<0.01), and CLS presence (p<0.05) in obese mice; while it increased macrophage and CLS presence (p<0.01), MCP-1 expression (p<0.05), and M2 polarization (p<0.05) in lean mice. MCP-1 was associated with the proliferation of CLS, showing the first image demonstrating a potential role of this chemokine in the development of these structures. Altogether, these results confirm, for the first time, the "bioregulatory effect of exercise" in the adipose tissue: reducing inflammation in individuals with an elevated inflammatory setpoint, but stimulating this response of the immune system in healthy individuals.

Background: In the pathogenesis of knee osteoarthritis (KOA), inflammatory mediators play an important role. However, the precise underlying mechanism by which regular exercise therapy (ET) exert effects on the immune system in KOA patients is unknown.

Objectives: The aim of this systematic review was to investigate the basal and acute effects of ET on inflammatory biomarkers and brain derived neurotrophic factor (BDNF) in KOA patients.

Methods: PubMed, Web Of Science and PEDro were systematically searched for appropriate studies. If possible, a meta-analysis was performed or an approximation of the effect size (ES) was calculated. Risk of bias was scored using the Cochrane ROB 2.0 or ROBINS-tools.

Results: Twenty-one studies involving 1374 participants were included. Fifteen articles focused on basal exercise effects, four on acute effects, and two on both. Biomarker analysis (n=18) was performed in synovial fluid (n=4) or serum/plasma (n=17). A meta-analysis demonstrated that basal CRP was reduced in KOA patients 6-18 weeks weeks after ET (MD: -0.17;95%CI[-0.31;-0.03]), while IL-6 (MD: 0.21;95%CI[-0.44;0.85]), and TNF-α (MD: -0.57;95%CI[-1.47;0.32]), levels did not significantly change. Also, sTNFR1/2 did not change significantly after ET. For other biomarkers, insufficient data were available to perform a meta-analysis. Nevertheless, a low degree of evidence was found for a decrease in IL-6 (ES:-0.596 & -0.259 & -0.513), an increase in sTNFR1 (ES:2.325), a decrease in sTNFR2 (ES:-0.997) and an increase in BDNF (ES:1.412). Locally, intra-articular IL-10 (ES:9.163) increased, and IL1β (ES:-6.199) and TNF-α decreased (ES:-2.322) after ET. An acute exercise session elicited a myokine response (ES IL-6:0.314), and an increase in BDNF (no ES-data). No inflammatory effect (ES CRP:0.052; ES TNF-α:-0.019 & 0.081) following an acute bout of training was found. However, a single bout of exercise elicited a decrease in intra-articular IL-10 (no ES-data).

Conclusion: ET can induce circulatory and intra-articular anti-inflammatory effects in patients with KOA. The antiinflammatory properties have important implications for informing these patients and clinicians about the underlying effects of ET.

Background: Exercise might exert anti-tumoral effects in adult cancers but this question remains open in pediatric tumors, which frequently show a different biology compared to adult malignancies. We studied the effects of an exercise intervention on physical function, immune variables and tumoral response in a preclinical model of a highly aggressive pediatric cancer, high-risk neuroblastoma (HR-NB).

Methods: 6-8-week-old male mice with orthotopically-induced HR-NB were assigned to a control (N = 13) or exercise (5-week combined [aerobic+resistance]) group (N = 17). Outcomes included physical function (cardiorespiratory fitness [CRF] and muscle strength), as well as related muscle molecular indicators, blood and tumor immune cell and molecular variables, tumor progression, clinical severity, and survival.

Results: Exercise attenuated CRF decline (p=0.029 for the group-by-time interaction effect), which was accompanied by higher muscle levels of oxidative capacity (citrate synthase and respiratory chain complexes III, IV and V) and an indicator of antioxidant defense (glutathione reductase) in the intervention arm (all p≤0.001), as well as by higher levels of apoptosis (caspase-3, p=0.029) and angiogenesis (vascular endothelial growth factor receptor-2, p=0.012). The proportion of 'hot-like' (i.e., with viable immune infiltrates in flow cytometry analyses) tumors tended to be higher (p=0.0789) in the exercise group (76.9%, vs. 33.3% in control mice). Exercise also promoted greater total immune (p=0.045) and myeloid cell (p=0.049) infiltration within the 'hot' tumors, with a higher proportion of two myeloid cell subsets (CD11C+ [dendritic] cells [p=0.049] and M2-like tumor-associated macrophages [p=0.028]), yet with no significant changes in lymphoid infiltrates or in cirulating immune cells or chemokines/cytokines. No training effect was found either for muscle strength or anabolic status, cancer progression (tumor weight and metastasis, tumor microenvironment), clinical severity, or survival.

Conclusions: Combined exercise appears as an effective strategy for attenuating physical function decline in a mouse model of HR-NB, also exerting some potential immune benefits within the tumor, which seem overall different from those previously reported in adult cancers.

Respiratory viruses are the most frequent causative agents of disease in humans and thus also in elite athletes. The COVID-19 pandemic has recently emphasized the entire spectrum of respiratory tract infections worldwide. Understanding the basic elements of respiratory viral infections is a fundamental requirement from the perspective of etiological diagnostics, treatment, and prevention strategy planning, as well as resource allocation.