Exercise Immunology Review最新文献

Background: Butyrate delivery to the large bowel may positively modulate commensal microbiota and enhance immunity.

Objective: To determine the effects of increasing large bowel butyrate concentration through ingestion of butyrylated high amylose maize starch (HAMSB) on faecal biochemistry and microbiota, and markers of immunity in healthy active individuals.

Design: Male and female volunteers were assigned randomly to consume either two doses of 20 g HAMSB (n = 23; age 37.9 +/- 7.8 y; mean +/- SD) or a low amylose maize starch (LAMS) (n = 18; age 36.9 = 9.5 y) twice daily for 28 days. Samples were collected on days 0, 10 and 28 for assessment of faecal bacterial groups, faecal biochemistry, serum cytokines and salivary antimicrobial proteins.

Results: HAMSB led to relative increases in faecal free (45%; 12-86%; mean; 90% confidence interval; P = 0.02), bound (950%; 563-1564%; P < 0.01) and total butyrate (260%; 174-373%; P < 0.01) and faecal propionate (41%; 12-77%; P = 0.02) from day 0 to day 28 compared to LAMS. HAMSB was also associated with a relative 1.6-fold (1.2- to 2.0-fold; P < 0.01) and 2.5-fold (1.4- to 4.4-fold; P = 0.01) increase in plasma IL-10 and TNF-alpha but did not alter other indices of immunity. There were relative greater increases in faecal P. distasonis (81-fold (28- to 237-fold; P < 0.01) and F. prausnitzii (5.1-fold (2.1- to 12-fold; P < 0.01) in the HAMSB group.

Conclusions: HAMSB supplementation in healthy active individuals promotes the growth of bacteria that may improve bowel health and has only limited effects on plasma cytokines.

Purpose: The capacity of whole blood cultures to produce cytokines in response to endotoxin (LPS) was studied in athletes before, 30 min after, 3 h after and 24 h after a half-marathon run.

Methods: Eight well trained men and 8 well trained women (6 of them in the late luteal phase of their cycle) participated. EDTA blood was incubated with or without LPS for 1 h, and cytokine concentration and gene expression were determined. To quantify LPS-dependent release on a per monocyte basis (LDR), the mean values of the difference (delta) between cytokine concentration in stimulated and unstimulated cultures, normalized to monocyte numbers, were calculated.

Results: LDR of TNF-alpha was significantly reduced by exercise with identical kinetic in men and women. TNF-alpha mRNA expression was slightly down-regulated following exercise (P < 0.05), but significantly so only in women. LDR of IL-6 was also reduced, but with a faster kinetic in women than in men. Similarly, 30 min post-exercise; LDR and spontaneous release of IL-1ra were significantly less in women than men. Concomitantly, IL-Ira mRNA was significantly elevated in unstimulated and in stimulated cultures in men only. IL-10 and IL-10 mRNA were significantly induced 30 min following exercise in absence of any detectable LDR. Women showed significantly lower levels than men. LDR and spontaneous release of IL-8 was enhanced in men and TGF-beta1 in women. A significant up-regulation was seen in unstimulated IL-8 mRNA for women and LPS-stimulated IL-8 mRNA expression for men following exercise.

Conclusion: Altogether, LPS-dependent ex vivo cytokine release was strongly influenced by exercise and these changes could only in part be attributed to changes in messenger RNA. Results for IL-1ra, IL-6 and IL-10 pointed to a less pronounced anti-inflammatory response in women as compared with men. Our results also indicate an early production of IL-10 by peripheral blood cells in response to exercise.

The purpose of this study was to determine the relationships among delayed-onset muscle soreness (DOMS), muscle damage and inflammatory responses to eccentric exercise and investigate the underlying mechanisms. Nine healthy males performed one-leg calf-raise exercise with their right leg on a force plate. They performed 10 sets of 40 repetitions of exercise at 0.5 Hz by the load corresponding to the half of their body weight, with a rest for 3 min between sets. DOMS was evaluated by a visual analogue scale (VAS). Blood and urine samples were collected before and 2, 4, 24, 48, 72 and 96 h post-exercise. Blood samples were analyzed for leucocyte differential counts and neutrophil functions (migratory activity and oxidative burst activity). We also determined a serum marker of muscle damage, myoglobin (Mb), and plasma and urinary prostaglandin E2 as an algesic substance. As for the inflammatory mediators, plasma and urine were analyzed for cytokines (interleukin (IL)-1beta, IL-1 receptor antagonist, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p40, IL-12p70, tumour necrosis factor-alpha, interferon-gamma, monocyte chemotactic protein-1, granulocyte colony-stimulating factor, macrophage colony-stimulating factor, and granulocyte macrophage colony-stimulating factor), leucocyte activation markers (calprotectin and myeloperoxidase), and neutrophil chemotactic factor complement 5a. All subjects reported muscle soreness on subsequent days and VAS peaked at 72 h after exercise. Serum Mb concentration significantly increased (p < 0.05) at 72 h after exercise as compared with the pre-exercise values which was correlated with the increases in VAS at 72 h (r = 0.73, p < 0.05). Circulating neutrophil count and migratory activity increased significantly (p < 0.01, and p < 0.05, respectively) at 4 h after exercise, whereas there were no significant changes in the other plasma and urinary inflammatory mediators. These results suggest that neutrophils can be mobilized into the circulation and migrate to the muscle tissue several hours after the eccentric exercise. There were also positive correlations between the exercise-induced increases in neutrophil migratory activity at 4 h and the increases in Mb at 48 h (r = 0.67, p < 0.05). These findings suggest that neutrophil mobilization and migration after exercise may be involved in the muscle damage and inflammatory processes.

Exercise-induced muscle damage is an important topic in exercise physiology. However several aspects of our understanding of how muscles respond to highly stressful exercise remain unclear In the first section of this review we address the evidence that exercise can cause muscle damage and inflammation in otherwise healthy human skeletal muscles. We approach this concept by comparing changes in muscle function (i.e., the force-generating capacity) with the degree of leucocyte accumulation in muscle following exercise. In the second section, we explore the cytokine response to 'muscle-damaging exercise', primarily eccentric exercise. We review the evidence for the notion that the degree of muscle damage is related to the magnitude of the cytokine response. In the third and final section, we look at the satellite cell response to a single bout of eccentric exercise, as well as the role of the cyclooxygenase enzymes (COX1 and 2). In summary, we propose that muscle damage as evaluated by changes in muscle function is related to leucocyte accumulation in the exercised muscles. 'Extreme' exercise protocols, encompassing unaccustomed maximal eccentric exercise across a large range of motion, generally inflict severe muscle damage, inflammation and prolonged recovery (> 1 week). By contrast, exercise resembling regular athletic training (resistance exercise and downhill running) typically causes mild muscle damage (myofibrillar disruptions) and full recovery normally occurs within a few days. Large variation in individual responses to a given exercise should, however be expected. The link between cytokine and satellite cell responses and exercise-induced muscle damage is not so clear The systemic cytokine response may be linked more closely to the metabolic demands of exercise rather than muscle damage. With the exception of IL-6, the sources of systemic cytokines following exercise remain unclear The satellite cell response to severe muscle damage is related to regeneration, whereas the biological significance of satellite cell proliferation after mild damage or non-damaging exercise remains uncertain. The COX enzymes regulate satellite cell activity, as demonstrated in animal models; however the roles of the COX enzymes in human skeletal muscle need further investigation. We suggest using the term 'muscle damage' with care. Comparisons between studies and individuals must consider changes in and recovery of muscle force-generating capacity.

Regular exercise and physical activity provide many health benefits and are encouraged by medical professionals for the primary prevention of and adjuvant treatment of breast cancer Current consensus in the discipline of exercise oncology is that both regular physical activity and exercise training exert some protective effect against breast cancer risk, and may reduce morbidity in some advanced cases. While there is growing interest in the role of exercise and physical activity in breast cancer prevention, it is currently unclear how exercise may modulate tumor behavior. The tumor microenvironment is populated by stromal cells such as fibroblasts and adipocytes, as well as macrophages. Termed tumor-associated macrophages (TAMs), these immune cells are highly plastic and respond to different signals from the cancer microenvironment, causing them to either display tumor-promoting or tumor-suppressing phenotypes. Because of such plasticity, there has been considerable interest by immunologists to develop immunotherapies based on skewing the behavior of TAMs to become cancer-suppressive. Previous studies have indirectly shown the ability of exercise training to induce an anti-tumor effect of macrophages, although the studies did not address this in the tumor microenvironment. Nevertheless, this opens up the possibility that regular exercise training may exert a protective innate immune effect against breast cancer, potentially by inducing a cancer-suppressing phenotype of TAMs. This review will describe potential mechanisms through which exercise may modulate the behavior of TAMs.

Objective: To determine the changes in endurance capacity as well as in metabolic, hormonal and inflammatory markers induced by endurance training combined with a soy,protein based supplement.

Design: Randomized controlled study consisting of moderate endurance training without (GO) or with (G1) a soy protein based supplement.

Subjects: Two groups of 15 subjects (10 males and 5 females in each group): healthy sports students aged 23.6 +/- 1.9 years.

Measurements: Body composition (body mass (BM), body density (BD) by air displacement) and physical fitness (determined by treadmill ergometry) were measured at baseline and after 6 weeks of the intervention; changes in circulating metabolic and hormonal parameters (glucose, lactate, urea, uric acid, ammonia, cortisol, insulin, IGF-1), and exercise-induced stress and inflammatory markers (CK, LDH, myoglobin, hs-CRP, IL-6, IL-10, blood cell counts) were determined after the intervention period in afield test (11.5 km running on hilly ground).

Results: 30 participants completed the 6-week study; 28 students were able to perform the field test. No significant changes in BM and BD were noted after intervention with only slight increases in running performance and maximum aerobic capacity in the total group (2%, p=0.016). Subjects in the G1 group showed significant improvements in running velocity and lower lactate values following the intervention (-12%, p=0,003). In addition, the G1 group showed significantly lower differences in the exercise-induced increase of metabolic parameters (triglycerides, uric acid) and insulin in the post-exercise recovery period.

Conclusions: Our data suggest that moderate endurance training in combination with a soy-based protein supplement improves aerobic energy supply and metabolic function in healthy sports students, even without changes in body composition and without changes in the exercise-induced stress and inflammatory reaction.

Background: Exhaustive exercise induces apoptosis and oxidative stress in systemic organs and tissues and is associated with increased levels of pro-inflammatory cytokines. The effects of acute exercise on cytokine expression and apoptosis of immune cells in the central nervous system (CNS) have not been well characterized.

Purpose: We investigated the effects of a single bout of strenuous exercise on the expression of TNF-alpha, IL-6, and IL-beta, as well as the apoptotic status of cells in the hippocampus of healthy mice. To compare central vs. systemic differences, cytokine expression in the intestinal lymphocytes of a subset of mice were also assessed.

Methods: Female C57BL/6 mice were divided into three groups: sedentary controls (NOTREAD) (n = 22), treadmill exercise with immediate sacrifice (TREAD-Imm) (n = 21), or treadmill exercise with sacrifice after 2 hours (TREAD-2h). TNF-alpha, IL-6, and IL-1beta expression in the hippocampus and intestinal lymphocytes were measured by Western blot analysis. Percentages of hippocampal cells undergoing apoptosis (Annexin+) or necrosis (Propidium Iodide+) were determined through flow cytometry. Plasma levels of 8-isoprostane and corticosterone were measured using commercially available EIA kits.

Results: Acute treadmill exercise led to significant decreases in TNF-alpha (p<0.05) and increases in IL-6 (p<0.05) expression in the hippocampus of healthy mice. No effects of acute exercise on the apoptotic status of hippocampal cells were observed. In intestinal lymphocytes, the exercise bout led to significant increases in TNF-alpha (p<0.05), IL-6 (p<0.05), and IL-1beta (p<0.05). Acute exercise was associated with a significant increase in both plasma 8-isoprostane (p<0.05) and corticosterone (p<0.05) levels.

Conclusion: Acute exercise differentially affects the pattern ofpro-inflammatory cytokine expression in the hippocampus compared to intestinal lymphocytes and, further, does not induce apoptosis in hippocampal cells.

Subsequent to prolonged exhausting exercise a transient immunosuppression is often observed in athletes. This so-called "open window" results in a reduced resistance of the athletes to viral and bacterial infections after an exhaustive exercise bout. Concerning the effect of bacterial endotoxin contact after exhausting exercise in transplant recipients, who are innately immunosuppressed by their medication, no data exists at present. After performing 81 km cycling, including ascending more than 1800 m in altitude, peripheral blood from 10 male kidney transplant recipients and from 10 healthy controls matched for age and gender was obtained. Simulating contact of the athletes with a pathogen post-exercise, the blood samples were incubated with Lipopolysaccharides (LPS). Thereafter microarray analysis was performed. Microarray analysis revealed a markedly oppositional pattern of gene expression in transplant recipients compared with their controls after LPS incubation. Especially immune response genes were significantly over-represented in controls immediately after the exhaustive exercise bout with LPS stimulation, whereas numerous apoptotic genes were over-represented in transplant recipients. Merging our previous data with these recent findings it should be discussed if transplant recipients need to reduce their immunosuppressive medication before performing exhaustive exercise.

Resistance exercise induces changes in leukocyte redistribution, phenotypical surface expression and leukocyte functionality. Several factors have been shown to alter the temporal pattern and/or magnitude of response including manipulation of acute program variables, the aging process, and nutritional supplementation. Rest period length and load can modify the temporal pattern and/or magnitude of leukocytosis post exercise. Aging diminishes both the duration and magnitude of the post exercise leukocytosis and reduces leukocyte functionality. The few studies that assessed the effects of nutritional supplements (e.g., carbohydrate, whey protein, caffeine) peri-resistance exercise showed minimal effects on leukocyte responses. Sex differences exist in the timing and magnitude of leukocyte infiltration into skeletal muscle. The immune response to resistance exercise is only a small part of the recovery paradigm. A better understanding of how acute program variables and other factors such as aging, sex and nutritional supplementation affect the immune response to resistance exercise is important in the context of improving recovery, performance and health.