NK cell recruitment and exercise: Potential immunotherapeutic role of shear stress and endothelial health

The Effect of Acute Physical Exercise on Natural Killer Cells Populations and Cytokine Levels in Healthy Women

Physical exercise generates a systemic response in the immune system. It has been observed that cell populations respond to exercise stimuli, especially Natural Killer cells, whose number increase within minutes of starting physical exertion. This study aimed to evaluate the acute effect of moderate- and high-intensity exercise on immunological markers in healthy women. As specific objectives, the percentages of CD3-CD56+ Natural Killer total cells, CD56brightCD16dim effector subpopulation, CD56dimCD16bright cytotoxic subpopulation, NKG2A inhibition receptor, NKG2D activation receptor, and NKT cells were analyzed. In addition, the levels of the cytokines IL-1β, IL-6, IL-8, IL-10, IL-12p70, and TNF and the chemokines CCL5/RANTES, CXCL9/MIG, CCL2/MCP-1, and CXCL10/IP-10 were also analyzed. Natural Killer total cells showed an increase in their percentage in both exercise protocols (p = 0.001 for the moderate-intensity group and p = 0.023 for the high-intensity group); however, only in the high-intensity exercise session was there an increase in the CD56dimCD16bright cytotoxic subpopulation (p = 0.014), as well as a decrease in CD56brightCD16dim effector subpopulation (p = 0.001) and their NKG2A inhibition receptor (p = 0.043). An increase in IL-6 was observed after the high-intensity exercise session (p = 0.025). Conclusions. Physical exercise influences immunological markers and shows an acute response to moderate- or high-intensity exercise.

Chronic Running Exercise Regulates Cytotoxic Cell Functions and Zinc Transporter SLC39A10/ZIP10 Levels in Diabetic Rats

The aim of this study is to investigate how chronic running exercise affects ZIP10 levels in thymus and spleen tissue as well as immune parameters in diabetic rats. A total of 40 adult male Wistar rats were divided into 4 equal groups: group 1, control; group 2, exercise control; group 3, diabetes; group 4, diabetes + exercise. Diabetes was induced by injecting intraperitoneal streptozotocin (STZ) at a dose of 40 mg/kg twice with 24-h intervals to the animals in groups 3 and 4. The animals in group 2 and group 4 underwent exercise for 45 min on the rat treadmill for 4 weeks at 20 m/min. Twenty-four hours after the last running exercise, the animals were sacrificed under general anesthesia. Immunological parameters were determined by flow cytometric method; tissue ZIP 10 levels were determined by ELISA method. The diabetic group had the lowest natural killer (NK) and natural killer T (NKT) cells percentages. Chronic exercise partially improved NK and NKT cell percentages in diabetic rats. The diabetic group had the lowest ZIP10 levels in spleen and thymus tissue. ZIP10 values in spleen and thymus tissue of diabetes exercise group were significantly higher than diabetes group. The results of our study show that the impaired cytotoxic cell functions in diabetes are partially corrected with 4 weeks of chronic exercise, and that the suppressed ZIP 10 levels in diabetic rats are reversed by 4 weeks of chronic exercise.

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

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

Natural Killer Cell Mobilization in Breast and Prostate Cancer Survivors: The Implications of Altered Stress Hormones Following Acute Exercise

Natural killer (NK) cells from the innate immune system are integral to overall immunity and also in managing the tumor burden during cancer. Breast (BCa) and prostate cancer (PCa) are the most common tumors in U.S. adults. Both BCa and PCa are frequently treated with hormone suppression therapies that are associated with numerous adverse effects including direct effects on the immune system. Regular exercise is recommended for cancer survivors to reduce side effects and improve quality of life. Acute exercise is a potent stimulus for NK cells in healthy individuals with current evidence indicating that NK mobilization in individuals with BCa and PCa is comparable. NK cell mobilization results from elevations in shear stress and catecholamine levels. Despite a normal NK cell response to exercise, increases in epinephrine are attenuated in BCa and PCa. The significance of this potential discrepancy still needs to be determined. However, alterations in adrenal hormone signaling are hypothesized to be due to chronic stress during cancer treatment. Additional compensatory factors induced by exercise are reviewed along with recommendations on standardized approaches to be used in exercise immunology studies involving oncology populations.

What Do Primary Healthcare Providers and Complementary and Alternative Medicine Practitioners in Palestine Need to Know about Exercise for Cancer Patients and Survivors: A Consensual Study Using the Delphi Technique

Background

Exercise has physiologic and psychological benefits for cancer patients and survivors. Today, various exercises are recommended as adjunct to therapies for cancer patients and survivors. This study was conducted to develop a consensual core list of important knowledge items that primary healthcare providers and complementary and alternative medicine (CAM) practitioners need to know on the role of exercises and physical activities in stimulating anticancer immunity.

Methods

Knowledge items were collected following interviews with key contact experts (4 oncologists, 3 exercise and medicine specialists, 2 researchers, 2 cancer patients, and 3 survivors) and extensive literature review. The collected knowledge items were rated by 9 researchers who conducted research on exercise and cancer. A modified two-iterative Delphi technique was employed among a panel (n = 65) of healthcare providers and CAM practitioners to develop the consensual core list of knowledge items.

Results

Of the 49 knowledge items, consensus was achieved on 45 (91.8%) items in 6 categories. Of those, 9 (20.0%) were general items on recommending moderate to vigorous habitual exercises and physical activities. The rest of items were related to the effects of habitual exercises and physical activities on the functions of immune system and exposure to carcinogens 16 (35.6%), anticancer therapies 12 (26.7%), metastasis of cancer 3 (6.7%), metabolism within tumors 3 (6.7%), and myokines release 2 (4.4%).

Conclusion

Formal consensus was achieved for the first time on a core list of knowledge items on how exercises and physical activities might stimulate anticancer immunity. This core list might be considered at the time of developing training/educational interventions and/or continuing education for primary healthcare providers and CAM practitioners. Future studies are still needed to investigate if such consensual lists might improve congruence in cancer care continuum and improve survival rates and wellbeing of cancer patients and survivors.

Exposure to an enriched environment promotes the terminal maturation and proliferation of natural killer cells in mice

The maturation of natural killer (NK) cells is critical for the acquisition of robust effector functions and the immune response to tumors. However, the influence of psychological stress on NK-cell maturation remains unknown. In this study, we investigated the alteration of NK-cell maturation in response to enriched environment (EE) exposure, which induced eustress, or positive stress, in mice. Analysis of markers representing distinct mature stages revealed that EE promoted the terminal maturation of NK cells both centrally in the bone marrow and peripherally in the spleen and blood. Additionally, EE increased CD27⁺ immature and intermediate-mature NK cell proliferation in the bone marrow. Furthermore, EE exposure brought about a similar promoting effect on NK-cell maturation in tumor-bearing mice. In tumor-bearing mice, EE substantially enhanced the proliferative potential of splenic CD27⁺ NK cells compared to those in the bone marrow. EE-housed mice displayed a tumor-resistant phenotype and an increased proportion of intratumoral NK cells, especially CD11b⁺ CD27^- mature NK cells, while splenectomy abolished the tumor-retardant effect caused by EE and EE-induced NK-cell infiltration into tumors. Given that our previous study demonstrated an important role for NK cells in EE-induced tumor inhibition, the findings of this study further indicate that the enhanced maturation and proliferation of splenic NK cells may contribute to EE-induced tumor inhibition to some extent. Taken together, the results of this study suggest a positive modulating effect of environment-induced eustress on NK-cell maturation, with potential implications for understanding how eustress boosts NK-cell antitumor immunity.

Effects of Acute and Chronic Exercise on Immunological Parameters in the Elderly Aged: Can Physical Activity Counteract the Effects of Aging?

Immunosenescence is characterized by deterioration of the immune system caused by aging which induces changes to innate and adaptive immunity. Immunosenescence affects function and phenotype of immune cells, such as expression and function of receptors for immune cells which contributes to loss of immune function (chemotaxis, intracellular killing). Moreover, these alterations decrease the response to pathogens, which leads to several age-related diseases including cardiovascular disease, Alzheimer's disease, and diabetes in older individuals. Furthermore, increased risk of autoimmune disease and chronic infection is increased with an aging immune system, which is characterized by a pro-inflammatory environment, ultimately leading to accelerated biological aging. During the last century, sedentarism rose dramatically, with a concomitant increase in certain type of cancers (such as breast cancer, colon, or prostate cancer), and autoimmune disease. Numerous studies on physical activity and immunity, with focus on special populations (i.e., people with diabetes, HIV patients) demonstrate that chronic exercise enhances immunity. However, the majority of previous work has focused on either a pathological population or healthy young adults whilst research in elderly populations is scarce. Research conducted to date has primarily focused on aerobic and resistance exercise training and its effect on immunity. This review focuses on the potential for exercise training to affect the aging immune system. The concept is that some lifestyle strategies such as high-intensity exercise training may prevent disease through the attenuation of immunosenescence. In this context, we take a top-down approach and review the effect of exercise and training on immunological parameters in elderly at rest and during exercise in humans, and how they respond to different modes of training. We highlight the impact of these different exercise modes on immunological parameters, such as cytokine and lymphocyte concentration in elderly individuals.