The Effects of a Dynamic Warm-Up on Exercise-Induced Redistribution of Monocytes and Natural Killer Cells

Proportions of leukocyte subsets in peripheral blood are altered post-exercise and return to baseline during recovery. This is caused in part by exercise-induced increases in stress hormones. Inclusion of a pre-exercise dynamic warm-up has been shown to decrease markers of cardiovascular stress during exercise. However, whether a warm-up can attenuate changes to the immune system with exercise has not yet been examined PURPOSE: To compare monocyte and natural killer (NK) cell mobilization following a bout of high intensity aerobic exercise with and without a dynamic pre-exercise warm-up. METHODS: 16 physically active adults (7 women, 27.8±4.4 years) cycled 30 minutes at 80% age predicted maximum heart rate with and without warm-up in a randomized counter-balanced order. Warm-up (10% increase in wattage each min for 10 min) was provided immediately prior to the exercise. Blood collected pre-, post- and 1hour post- exercise was analyzed by flow cytometry to characterize cell populations. Differences in cell proportions across time points and conditions were assessed by maximum likelihood linear mixed models. RESULTS: A significant effect of time was shown in monocytes [Classical (CM), intermediate (IM) and non-classical (NM)] and NK cells (PCONCLUSION: Our data indicate that inclusion of a warm-up does not alter exercise-induced perturbations of monocytes and NK cells in a population of physically active young adults. Future work will consider additional cell subsets

Exercise Mobilizes Early and Late Differentiated CD8 T cells Expressing a Marker of Exhaustion

T cell differentiation occurs following activation of key functions, such as proliferation and cytokine production. Naïve (NA) and central memory (CM) T cells are early differentiated, whereas effector memory (EM) and RA+ effector memory cells (EMRA) are later differentiated. CD57 expression, a putative marker of exhaustion, has also been used to identify later differentiated cells, although recent data indicate CD57 can also be expressed by NA and CM. Exercise mobilizes EM and EMRA to a greater extent than NA and CM. Separately, exercise has been shown to preferentially mobilize CD57+ cells. Whether these exercise responsive CD57+ cells arise from highly differentiated T cells or from across T cell subsets is not known. PURPOSE: Determine whether CD57+ cells within NA, CM, EM, and EMRA T cell subsets are mobilized to a greater extent that CD57- cells within the same subsets. METHODS: Seventeen participants (7 female; aged 18-40 years) cycled 30 minutes at 80% of their estimated heart rate max. Venous blood obtained pre, post, and 1-hour post-exercise was analyzed by flow cytometry. CD45RA and CCR7 expression within CD8+ T cells identified NA, CM, EM, and EMRA subsets, and CD57 expression within each was quantified. The fold change (FC) in cell frequency was calculated post exercise (post/pre) and 1h post-exercise (1h-post/post). Data were natural log transformed and paired-samples t-tests used to compare CD57+ and CD57- FC within each subset. Separate models compared post-exercise and 1h post-exercise FC. RESULTS: Within NA, CD57+ cells were mobilized to a greater extent post exercise than CD57- (FC = 0.92 vs 0.10; t= 4.96, pd= 0.68), as well as 1-hour post-exercise (FC = -0.98 vs -0.20; t= -3.91, p=0.001, d=0.82). While CM CD57+ and CD57- cells did not differ in post-exercise FC, CD57+ CM exhibited a greater relative decline 1h-post exercise than CD57- (FC= -0.65 vs -0.20; t= -4.55, pd=0.41). Within EM, CD57+ cells were mobilized to a greater extent post exercise than CD57- (FC = 0.66 vs 0.35; t= 3.77, p=0.002, d=0.35), as well as 1-hour post-exercise (FC = -0.82 vs-0.37; t= -4.17, pd=0.45). Within EMRA cell subsets, CD57+ cells were also mobilized to a greater extent immediately post-exercise than CD57- (FC = 0.84 vs 0.51; t= 4.69, pd=0.29) as well as 1-hour post-exercise (FC= -1.06 vs -0.64; t=4.69, pd=0.37). CONCLUSION: Relative to CD57- cells, CD57+ cells within NA, CM, EM, and EMRA CD8 T-cells subsets exhibit a greater mobilization both into and out of the bloodstream after exercise. These results indicate that CD57 expression associates with greater exercise-response in CD8 T cells, even amongst early differentiated subsets. These results could help to shed light on the denotation of CD57 expression

Treadmill Walking Increases Percent of Circulating Monocytes (CD14+) Expressing CX3CR1 In Older Adults

CX3CR1 is a chemokine receptor for the chemokine CX3CL1. Expression of CX3CR1 may influence the inflammatory response of the innate immune system. The PURPOSE: of this study was to examine the relationship between CX3CR1 expression on circulating monocytes with physical activity level and mode of exercise in healthy, older adults. METHODS: Twenty-four healthy older adults (63.0 ±5.0 years) were recruited for this study. Participants were divided into two groups based on self-reported physical activity level: physically active (PA) and physically inactive (PI). Participants completed a randomized complete crossover trial of 30 minutes moderate-vigorous intensity cardiorespiratory endurance (CRE) or resistance exercise (RE) on two separate visits. Blood samples were collected from each person at rest (PRE), immediately after exercise (POST), and 1-hr recovery after exercise (RECOV). Monocyte cell surface markers were measured by flow cytometry. RESULTS: PA participants (N=12, est. VO2max=45.3±16.8 mL·kg-1·min-1) had a higher estimated VO2max than the physically inactive participants (N=12, est. VO2max=35.0± mL·kg-1·min-1). Percent of circulating monocytes expressing CX3CR1 was higher (p\u3c0.05) in CRE RECOV (92.3%±2.5) than CRE POST (90.1%±2.98). No other differences (p≥0.05) were observed within the PA group between PRE, POST, and RECOV timepoints for the CRE or RE modes of exercise. No differences (p≥0.05) were observed within the PI group for time or mode of exercise. No differences (p≥0.05) were observed between the CRE and RT modes of exercise within the PA group or the PI group at each PRE, POST, and RECOV timepoints. CONCLUSION: Differences in monocyte expression of CX3CR1 were observed between the POST and RECOV stage following a 30-minutes CRE (treadmill) exercise intervention within the PA group. Time differences were observed between PA and PI groups. No other differences in CX3CR1 were observed within PA and PI groups following a 30-minute moderate-vigorous exercise intervention. Further research is needed to determine potential differences if CX3CR1 physical activity status and mode of exercise influence the inflammatory response of an acute exercise bout

Acute exercise enhances the expansion of cytotoxic T-cells specific to leukemia and melanoma antigens: implications for adoptive transfer immunotherapy?

INTRODUCTION: The ex vivo expansion of tumor-associated-antigen (TAA)-specific cytotoxic T-cells from healthy donors for adoptive transfer in cancer patients has been used successfully to prevent relapse after hematopoietic stem cell transplantation (HSCT). However, this therapy is limited by the difficulty in priming and expanding sufficient numbers of functional TAA-specific T-cells, as T-cells recognizing TAA are usually low in frequency and avidity in healthy donors. Furthermore, monocyte-derived dendritic cells (Mo-DC) are used for TAA-presentation, but their manufacture is limited by low blood monocyte numbers. Therefore, large and impractical numbers of blood cells are required to successfully expand TAA-specific T-cells. Acute exercise is well-known to transiently activate and increase the numbers of T-cells and monocytes in peripheral blood. We therefore hypothesized that the immune-enhancing effects of exercise could be harnessed to enhance the ex vivo expansion of TAA-specific T-cells for adoptive transfer immunotherapy. AIMS: To examine the effects of acute exercise on (1) the number and function of TAA-specific T-cells expanded ex vivo, and 2) the generation and function of mo-DC. METHODS: 12 healthy adults (mean ± SD: Age 27±2.6yrs) completed an acute bout of stair-running exercise (time: 104±17sec). Mo-DC generated from pre and post exercise blood samples were pulsed with the melanoma-associated-antigens MAGE-A4 and PRAME, the common tumor-antigen survivin, and the leukemia-associated-antigen WT-1. Autologous DC were used to expand TAA-specific T-cells obtained before and after exercise over 14-days. T-cells were enumerated and phenotyped by flow cytometry and function was assessed by ELISPOT and antigen-specific cytotoxicity. RESULTS: A greater number of mo-DC were generated from post-exercise blood samples (pre: 2.0±1.0 X106cells, post: 5.2±2.6 X106cells). This was due to the 1.7 fold increase in blood monocytes post-exercise, as the number of mo-DC generated per input CD14+cell did not differ (pre: 0.40±0.25, post: 0.59±0.36). Total T-cell expansion was increased post-exercise (fold-increase: pre: 2.48±0.75, post: 2.90±0.74). ELISPOT revealed that the majority of donors had enrichment in TAA-specific T-cells post-exercise, as T-cell lines expanded from post-exercise samples exhibited an increased interferon-gamma response to TAA compared to T-cell lines expanded from pre-exercise samples. Exercise had no effect on T-cell phenotype or antigen-specific cytotoxicity in the expanded cells. CONCLUSION: These data indicate that a single bout of exercise enhances mo-DC generation and the expansion of TAA-specific T-cells ex vivo. Exercise may therefore serve as an adjuvant to enhance the expansion of TAA-specific T-cells in healthy donors and improve the efficacy of adoptive transfer therapy in cancer patients

The Effects of 15 Minutes vs. 30 Minutes of Moderate Intensity Exercise on Lymphocytes, Monocytes and Granulocytes

Vigorous intensity exercise lasting 30 minutes or longer is well known to increase white blood cells, including lymphocytes, monocytes, and granulocytes, in blood. White blood cells are cells of the immune system that provide protection against infection and disease. However, the relative effects of 15 minutes vs 30-minutes of moderate intensity exercise on these variables are not known. PURPOSE: Compare 15 minutes vs 30 minutes of moderate-intensity exercise on the mobilization of white blood cells including lymphocytes (LYM), monocytes (MONO), and granulocytes (GRAN). METHODS: 9 healthy men and women across physical fitness levels were recruited (4 female, (mean ± standard deviation): 28.1 ± 9.7 years old). Following a 5-minute warm-up, participants were prescribed a 30-minute (min) exercise on a stationary bike at a moderate intensity (55% of heart rate reserve, calculated by (maximum heart rate - resting heart rate) × 55% of resting heart rate). A blood sample taken before, after 15 min, and after 30 min of exercise. Blood samples were analyzed with a hematology analyzer. Paired T tests were used to compare LYM, MONO, and GRAN between pre-exercise and 15 min exercise, and between 15 min and 30 min exercise. RESULTS: The number of LYM was greater at 15 min compared to pre-exercise (pre mean ± standard deviation: 2.12 x 103 ± 0.68 x 103 cells/μl, 15 min: 2.88 x 103 ± 1.22 x 103 cells/μl, p=.007). The number of MONO was greater at 15 min compared to pre (pre: 0.43 x 103 ± 0.12 x 103 cells/μl, 15 min: 0.61 x 103 ± 0.19 x 103 cells/μl, p= .006). The number of GRAN was greater at 15 min compared to pre (pre: 2.86 x 103 ± 0.60 x 103 cells/μl, 15 min: 4.00 x 103 ± 0.82 x 103 cells/μl, p= .002). On the other hand, the number of LYM, MONO, and GRAN in blood did not differ between 15 min and 30 min (all p\u3e.05). CONCLUSION: Cycling for just 15 minutes at a moderate intensity showed mobilization of the white blood cells (lymphocytes, monocytes, and granulocytes) into blood circulation. If used in the clinical setting, this has the potential to complement current medical therapies, giving patients with diseases and infections a stronger chance for recovery. However, this requires further investigation

Characterization of transitional memory CD4+ and CD8+ T-cell mobilization during and after an acute bout of exercise

T-cell subsets, including naïve (NA), central memory (CM), transitional memory (TM), effector memory (EM), and RA + effector memory (EMRA), differ in phenotype and function. T-cells are mobilized by exercise, with differences in the magnitude of mobilization between subsets. However, the response of TM T-cells to exercise has not yet been described. Further, T-cells expressing the late differentiation marker CD57 are known to be highly responsive to exercise, but the relative response of CD57 + and CD57- within T-cell subsets is unknown. We therefore aimed to characterize the exercise-induced mobilization of TM T-cells, as well as to compare the exercise response of CD57 + and CD57- cells within T-cell subsets.MethodsSeventeen participants (7 female; aged 18–40 years) cycled 30 min at 80% of their estimated maximum heart rate. Venous blood obtained pre, post, and 1H post-exercise was analyzed by flow cytometry. CD45RA, CCR7, and CD28 expression within CD4 + and CD8+ T-cells identified NA, CM, TM, EM, and EMRA subsets. CD57 expression within EM, EMRA, and CD28+ T-cells was also quantified. The relative mobilization of each subset was compared by calculating fold change in cell concentration during (ingress, post/pre) and after exercise (egress,1H post/post). Cytomegalovirus (CMV) serostatus was determined by ELISA and was considered in models.ResultsTM CD8+ T-cell concentration was greater post-exercise than pre-exercise (138.59 ± 56.42 cells/µl vs. 98.51 ± 39.68 cells/µl, p < 0.05), and the proportion of CD8 + with a TM phenotype was elevated 1H post-exercise (1H: 32.44 ± 10.38% vs. Pre: 30.15 ± 8.77%, p < 0.05). The relative mobilization during and after exercise of TM T-cells did not differ from NA and CM but was less than EM and EMRA subsets. Similar results were observed within CD4+ T-cells. CD57 + subsets of CD28+ T-cells and of EM and EMRA CD8+ T-cells exhibited a greater relative mobilization than CD57- subsets (all p < 0.05).ConclusionThese results indicate TM CD4 + and CD8+ T-cells are transiently mobilized into the blood with exercise, but not to as great of an extent as later differentiated EM and EMRA T-cells. Results also indicate CD57 identifies highly exercise responsive cells within CD8+ T-cell subsets

Measuring Pro- and Anti-Inflammatory Biomarkers Among Low-Income Hispanic Adults: A Feasibility and Pilot Assessment

Using the Orsmond and Cohen feasibility framework, the primary aim of this study was to assess the feasibility of the implementation of recruitment strategies, data collection procedures, and managerial resources needed to assess pro- and anti-inflammatory biomarkers from low-income, younger Hispanic adults. The secondary aim of this study was to describe the relationship between discrimination stress and inflammation as pilot work for future studies. Data were collected in a Houston-area community center from self-identifying Hispanic adults (ages 21–35) (August 2018). Inflammation was evaluated from blood samples, and interviewer-administered surveys in participants’ preferred language measured discrimination stress (Hispanic Stress Inventory-2 discrimination subscale). Spearman rank-order correlations evaluated the relationships between discrimination stress and inflammatory biomarkers. The recruitment strategies, data collection strategy, and the associated resources were evaluated and found to be feasible. While 50 participants consented to donate blood, five were too dehydrated for sample collection. Among the 45 participants [Mage = 28.9 (SD = 4.4), 17.8% U.S.-born, 42.2% 1.5 generation, 40% 1.0 generation], discrimination stress was negatively correlated with proinflammatory cytokine interleukin-8 (p \u3c 0.01). This study demonstrated feasibility using established benchmarks. The negative correlation between discrimination stress and interleukin-8 suggests discrimination stress may contribute to inflammatory dysregulation

Lymphocytes and monocytes egress peripheral blood within minutes after cessation of steady state exercise: A detailed temporal analysis of leukocyte extravasation

Acute exercise evokes an almost instantaneous lymphocytosis, followed by sustained lymphopenia that occurs within just 30–60 min after exercise cessation. The aim of this study was to characterize the immediate (order of minutes) post-exercise kinetics of lymphocyte and monocyte egress, and to determine whether this egress is associated with heart rate recovery following a single bout of steady state dynamic exercise. Eleven healthy subjects cycled for 30-min at ~70% of their estimated peak power. Blood samples were collected from an intravenous catheter before exercise, during exercise (E) at +15 and +30 min, and during passive recovery (R) at exactly +1, +2, +3, +4, +5 and +10 min after exercise cessation. Complete blood counts and flow cytometry were used to enumerate total monocytes, lymphocytes: CD3+ T-cells, CD4+ T-cells, CD8+ T-cells, NK-cells and γδ T-cells in whole blood. Both lymphocytes and monocytes displayed rapid egress kinetics, by R+3 the total numbers of all cell types examined were significantly lower than E+30. NK-cells egressed more rapidly than other lymphocyte subtypes, followed by CD8+, γδ, and then CD4+ T-cells. Further, the egress of NK-cells, CD4+, and CD8+ T-cells positively correlated with heart rate recovery after exercise cessation. In conclusion, lymphocyte and monocyte egress is rapid and occurs within minutes of exercise recovery, underscoring both the importance of collection time for post exercise blood samples, and the use of intravenous catheters to capture peak cell mobilization. The rate of egress may be dependent on how quickly hemodynamic equilibrium is restored on cessation of exercise and is, therefore, likely to be influenced by individual fitness levels

Human lymphocytes mobilized with exercise have an anti-tumor transcriptomic profile and exert enhanced graft-versus-leukemia effects in xenogeneic mice

BackgroundEvery bout of exercise mobilizes and redistributes large numbers of effector lymphocytes with a cytotoxic and tissue migration phenotype. The frequent redistribution of these cells is purported to increase immune surveillance and play a mechanistic role in reducing cancer risk and slowing tumor progression in physically active cancer survivors. Our aim was to provide the first detailed single cell transcriptomic analysis of exercise-mobilized lymphocytes and test their effectiveness as a donor lymphocyte infusion (DLI) in xenogeneic mice engrafted with human leukemia.MethodsPeripheral blood mononuclear cells (PBMCs) were collected from healthy volunteers at rest and at the end of an acute bout of cycling exercise. Flow cytometry and single-cell RNA sequencing was performed to identify phenotypic and transcriptomic differences between resting and exercise-mobilized cells using a targeted gene expression panel curated for human immunology. PBMCs were injected into the tail vein of xenogeneic NSG-IL-15 mice and subsequently challenged with a luciferase tagged chronic myelogenous leukemia cell line (K562). Tumor growth (bioluminescence) and xenogeneic graft-versus-host disease (GvHD) were monitored bi-weekly for 40-days.ResultsExercise preferentially mobilized NK-cell, CD8+ T-cell and monocyte subtypes with a differentiated and effector phenotype, without significantly mobilizing CD4+ regulatory T-cells. Mobilized effector lymphocytes, particularly effector-memory CD8+ T-cells and NK-cells, displayed differentially expressed genes and enriched gene sets associated with anti-tumor activity, including cytotoxicity, migration/chemotaxis, antigen binding, cytokine responsiveness and alloreactivity (e.g. graft-versus-host/leukemia). Mice receiving exercise-mobilized PBMCs had lower tumor burden and higher overall survival (4.14E+08 photons/s and 47%, respectively) at day 40 compared to mice receiving resting PBMCs (12.1E+08 photons/s and 22%, respectively) from the same donors (p<0.05). Human immune cell engraftment was similar for resting and exercise-mobilized DLI. However, when compared to non-tumor bearing mice, K562 increased the expansion of NK-cell and CD3+/CD4-/CD8- T-cells in mice receiving exercise-mobilized but not resting lymphocytes, 1-2 weeks after DLI. No differences in GvHD or GvHD-free survival was observed between groups either with or without K562 challenge.ConclusionExercise in humans mobilizes effector lymphocytes with an anti-tumor transcriptomic profile and their use as DLI extends survival and enhances the graft-versus-leukemia (GvL) effect without exacerbating GvHD in human leukemia bearing xenogeneic mice. Exercise may serve as an effective and economical adjuvant to increase the GvL effects of allogeneic cell therapies without intensifying GvHD

Can a Dynamic Warm-up Reduce the Magnitude of Immune Perturbation Following Vigorous Aerobic Exercise

Exercise transiently increases several leukocyte populations in peripheral blood in an intensity-dependent manner, with numbers returning to baseline or lower during recovery. This mobilization of immune cells is explained in part by sympathetic activity and the release of stress hormones (catecholamines and cortisol). The literature examining immune responses to exercise has by and large failed to control for the presence of a warm-up prior to the experimental bout. Gradually increasing exercise intensity over a period of minutes may reduce the stress of the exercise bout and thus may influence the immune response to a given exercise protocol. PURPOSE: To compare the mobilization of leukocyte subpopulations following a bout of high intensity aerobic exercise with and without a dynamic pre-exercise warm-up. METHODS: 8 physically active adults (4 women, 27±4 years) cycled 30 minutes at 80% heart rate maximum with and without warm-up in a randomized, counter-balanced order. Warm-up was provided immediately prior to the exercise, and involved increasing wattage by 10% each minute for 10 minutes starting at 10% of desired exercise intensity. Blood collected pre-, post- and 1-hour post- exercise was analyzed by flow cytometry to characterize cell populations. Differences in cell concentrations across time points and conditions were assessed by maximum likelihood linear mixed models. RESULTS: Exercise transiently increased lymphocyte concentration in blood, and the number and proportion of late differentiated CD8 T cells (main effects of time; pCONCLUSION: Inclusion of a dynamic warm-up prior to vigorous aerobic exercise lessens the exercise-induced mobilization of lymphocytes and late differentiated T cells. Athletes should include a dynamic warm-up to reduce immune perturbations during high intensity exercise