T cell activation and proliferation following acute exercise in human subjects is altered by storage conditions and mitogen selection

Glycoprotein 5-Derived Peptides Induce a Protective T-Cell Response in Swine against the Porcine Reproductive and Respiratory Syndrome Virus

We analyzed the T-cell responses induced by lineal epitopes of glycoprotein 5 (GP5) from PRRSV to explore the role of this protein in the immunological protection mediated by T-cells. The GP5 peptides were conjugated with a carrier protein for primary immunization and booster doses. Twenty-one-day-old pigs were allocated into four groups (seven pigs per group): control (PBS), vehicle (carrier), PTC1, and PTC2. Cytokine levels were measured at 2 days post-immunization (DPI) from serum samples. Cytotoxic T-lymphocytes (CTLs, CD8+) from peripheral blood were quantified via flow cytometry at 42 DPI. The cytotoxicity was evaluated by co-culturing primed lymphocytes with PRRSV derived from an infectious clone. The PTC2 peptide increased the serum concentrations of pro-inflammatory cytokines (i.e., TNF-α, IL-1β, IL-8) and cytokines that activate the adaptive cellular immunity associated with T-lymphocytes (i.e., IL-4, IL-6, IL-10, and IL-12). The concentration of CTLs (CD8+) was significantly higher in groups immunized with the peptides, which suggests a proliferative response in this cell population. Primed CTLs from immunized pigs showed cytolytic activity in PRRSV-infected cells in vitro. PTC1 and PTC2 peptides induced a protective T-cell-mediated response in pigs immunized against PRRSV, due to the presence of T epitopes in their sequences.

Evaluation of Biological Activity of New 1,2,4-Triazole Derivatives Containing Propionic Acid Moiety

To this day, the quest to find new drugs is still a challenge due to the growing demands of patients suffering from chronic inflammatory diseases and the need for the individualization of therapy. The aim of this research was to synthesize new 1,2,4-triazole derivatives containing propanoic acid moiety and to investigate their anti-inflammatory, antibacterial and anthelmintic activity. Compounds 3a-3g were obtained in reactions of amidrazones 1a-1g with succinic anhydride. Several analyses of proton and carbon nuclear magnetic resonance (¹H NMR, ¹³C NMR, respectively), as well as high-resolution mass spectra (HRMS), confirmed the structures of 1,2,4-triazole derivatives 3a-3g. Toxicity, antiproliferative activity and influence on cytokine release (TNF-α: Tumor Necrosis Factor-α, IL-6: Interleukin-6, IFN-γ: Interferon-γ, and IL-10: Interleukin-10) of the compounds 3a-3g were evaluated in peripheral blood mononuclear cells culture. Moreover, mitogen-stimulated cell culture was used for biological activity tests. The antimicrobial and anthelmintic activity of derivatives 3a-3g were studied against Gram-positive and Gram-negative bacterial strains and Rhabditis sp. culture. Despite the lack of toxicity, compounds 3a-3g significantly reduced the level of TNF-α. Derivatives 3a, 3c and 3e also decreased the release of IFN-γ. Taking all of the results into consideration, compounds 3a, 3c and 3e show the most beneficial anti-inflammatory effects.

Discovery of potent immune-modulating molecule taccaoside A against cancers from structures-active relationships of natural steroidal saponins

BACKGROUND

In recent years, the T-cell therapy and immune checkpoint inhibitors toward CTLA-4 and PD-1/PD-L1 axis antibody therapy have acquired encouraging success. However, most of patients were still not benefited with lots of troubles, such as low penetration of tissues/cells, strong immunogenicity and cytokine release syndrome, and long manufacturing process and expensive costs. By contrast, the immune-modulating small molecules possessed natural advantages to overcome these obstacles and might achieve greater success.

PURPOSE

Exploring the potent immune-modulating natural small molecules and revealing what kinds of molecules or structures with the immunomodulatory activity against cancers.

METHODS

A novel non-cytotoxic T-cell immunomodulating screening model was used to identify the cytotoxic/selective/immunomodulatory bioactivity for 148 natural steroidal saponins. The structure-activity relationships (SARs) research was used to reveal the key groups for immunomodulation/cytotoxicity/selectivity. The negative selection was used to isolate and purify the T-cell. The cell viability assay was used to measure the anti-cancer effect in vitro. The ELISA assay was used to detect the cytokines for IL-1β, IL-6, TNF-α, IFN-γ, IL-12, perforin and granzyme B (GZMB). The western blotting assay was used to research the immunomodulatory mechanism. The siRNA knockdown was used to generate the IFN-γ resistant melanoma cells. The NOG immune-deficient mice were used to evaluate the anti-tumor efficacy in vivo. The peripheral blood samples from 10 cancer patients were used to detect the broad population anti-tumor efficacy.

RESULTS

It was reported that the correlation among structures and immunomodulation/ cytotoxicity/selectivity, in which opening ring-F with 26-O-glucopyranosyl, disaccharide and trisaccharide chains at C-3, steric hindrance and polarity of C-22 were key immunomodulatory groups. Moreover, taccaoside A was identified as the most potent candidate against cancer cells, including non-small cell lung cancer, triple negative breast cancer, and the IFN-γ resistant melanoma, partly through enhancing T lymphocyte mTORC1-Blimp-1 signal to secrete GZMB. Besides, 10 patients derived T-cell also would be modulated against cancer cells in vitro. Moreover, the overall survival was great extended (>140 days vs 93 days) with nearly 100% tumor burden disappearance (0 mm³vs 1006 ± 79.5 mm³) in mice.

CONCLUSION

This work demonstrated one possibility for this concerned purpose, and identified a potent immune-modulating natural molecule taccaoside A, which might contribute to cancer immunotherapy in future.

Impact of acute exercise on peripheral blood mononuclear cells nutrient sensing and mitochondrial oxidative capacity in healthy young adults

Regular exercise is associated with changes in peripheral blood mononuclear cell (PBMC) proportions that have enhanced effector functions in young and old adults; however, the effects of acute exercise on PBMC nutrient sensors and metabolic function in active young adults is unknown. To fill this gap, activation status and nutrient-sensing mechanisms of PBMCs isolated from 21 healthy active adults (20-35 yr; 36.5 ± 6.3 V̇O2peak ) were characterized before and after 30 min of moderate-to-vigorous cycling (65%-75% V̇O2peak ). In addition, changes in PBMC mitochondrial respiratory function in response to exercise were assessed using high-resolution respirometry. There was an increase in the number of activated CD69+/CD4 (79% increase) and CD69+/CD8 (166% increase) T-cells in response to the acute bout of exercise, while the nutrient-sensing mechanisms remained unchanged. PBMC mitochondrial respiration did not increase on a cell-per-cell basis, however, mitochondrial oxidative capacity (OXPHOS) increased at the tissue level (18.6 pmol/(s*ml blood) versus 29.3 pmol/(s*ml blood); p < 0.05) in response to acute exercise. Thus, this study shows that acute exercise preferentially mobilizes activated T-cells while concomitantly increasing PBMC mitochondrial oxidative capacity at the tissue level, rather than acutely changing mitochondrial oxidative capacity at the cellular level in young adults.

The Impact of Exercise Serum on Selected Parameters of CD4+ T Cell Metabolism

CD4+ T cells are sensitive to peripheral changes of cytokine levels and metabolic substrates such as glucose and lactate. This study aimed to analyze whether factors released after exercise alter parameters of human T cell metabolism, specifically glycolysis and oxidative phosphorylation. We used primary human CD4+ T cells activated in the presence of autologous serum, which was collected before (CO) and after a 30-min exercise intervention (EX). In the course of activation, cells and supernatants were analyzed for cell viability and diameter, real-time oxygen consumption by using PreSens Technology, mRNA expression of glycolytic enzymes and complexes of the electron transport chain by real-time PCR, glucose, and lactate levels in supernatants, and in vitro differentiation by flow cytometry. EX did not alter T cell phenotype, viability, or on-blast formation. Similarly, no difference between CO and EX were found for CD4+ T cell activation and cellular oxygen consumption. In contrast, higher levels of glucose were found after 48 h activation in EX conditions. T cells activated in autologous exercise serum expressed lower HK1 mRNA and higher IFN-γ receptor 1. We suggest that the exercise protocol used was not sufficient to destabilize the immune metabolism of T cells. Therefore, more intense and prolonged exercise should be used in future studies.

Exercise acutely increases vitamin D receptor expression in T lymphocytes in vitamin D-deficient men, independent of age

NEW FINDINGS

What is the central question of this study? Does exercise affect vitamin D receptor expression in T lymphocytes in young, middle-aged and older adults? What is the main finding and its importance? Moderate-intensity cycling exercise increases vitamin D receptor expression in vitamin D-deficient men, independent of age, presenting a strategy to combat the prevalence of vitamin D deficiency.

ABSTRACT

Vitamin D plays a key role in the modulation of the immune system, mediated through the intracellular vitamin D receptor (VDR). Exercise has been shown to influence the activity and availability of the VDR. The aim of this study was to investigate the effect of age on basal immune cell (T-lymphocyte) VDR expression and the subsequent effect of acute aerobic exercise to modulate VDR expression in peripheral T cells. Thirty-five men were included in the study (mean ± SD: age 44 ± 17 years and body mass index 25.7 ± 3.1 kg/m² ), separated into three age groups: 18-30 (n = 12), 31-45 (n = 11) and 60-75 years (n = 12). Participants completed two trials [control (CON) and aerobic exercise (AE)], with blood samples collected pre- and postexercise (0, 1 and 3 h). Peripheral blood T cells were isolated and analysed for VDR expression by flow cytometry. The results show that advanced age is associated with lower VDR expression in T cells (882 ± 274, 796 ± 243 and 594 ± 174 geomean in the 18-30, 31-45 and 60-75 year age groups, respectively). Acute AE was successful at acutely increasing VDR expression in T cells, irrespective of age. Advanced age corresponds to a lower T-cell VDR expression, which might be responsible for age-associated development of chronic conditions and autoimmunity. Exercise was successful in increasing VDR expression in T cells irrespective of age and independent of exercise-induced T-cell mobilization.

Kinetics of activation marker expression after in vitro polyclonal stimulation of chicken peripheral T cells

A comprehensive analysis of T cell activation markers in chicken is lacking. Kinetics of T cell activation markers (CD25, CD28, CD5, MHC-II, CD44, and CD45) in response to in vitro stimulation of peripheral blood mononuclear cells with concanavalin A (Con A) were evaluated between two chicken lines selected for high and low levels of mannose-binding lectin in serum (L10H and L10L, respectively) by flow cytometry. L10H chickens showed a stronger response to Con A based on the frequency of T cell blasts in both the CD4⁺ and CD8⁺ compartment. The majority of the proliferating CD4⁺ and CD8⁺ T cells expressed CD25. Proliferating T cells were seen both in the CD4⁺  MHC-II^+/- and CD8⁺  MHC-II^+/- population. For both CD4⁺ and CD8⁺ T cells, frequencies of CD25⁺ and MHC-II⁺ T cells were increased 24 h after stimulation. CD28⁺ frequencies were only increased on CD8⁺ T cells 48 h after stimulation. An increase in the relative surface expression based on mean fluorescence intensity (MFI) upon activation was observed for most markers except CD5. For CD4⁺ T cells, CD28 expression increased 24 h after stimulation whereas MHC-II expression increased after 48 h. For CD8⁺ T cells, a tendency toward an increase in CD25 expression was observed. CD28 expression started to increase 24 h after stimulation and only a transient peak in MHC-II expression on CD8⁺ T cells was observed after 24 h. CD44 and CD45 expressed on CD4⁺ and CD8⁺ T cells increased 24-72 h after stimulation. In summary, the frequency of CD25⁺ and MHC-II⁺ T cells were shown to be early markers (24 h) for in vitro activation of both CD4⁺ and CD8⁺ T cells. Frequency of CD28⁺ T cells was a later marker (48 h) and only for CD8⁺ T cells. Surface expression of all markers (MFI) increased permanently or transiently upon activation except for CD5.

Effect of refrigeration of blood samples in lithium-heparin tubes on QuantiFERON TB Gold Plus test result

The QuantiFERON TB Gold Plus (QFT-Plus) test is a newly approved interferon-gamma releasing assay test for detecting latent tuberculosis. Although blood samples for QFT test can be refrigerated for 48 h in lithium-heparin tubes according to package inserts, no published data are available on the effects of sample refrigeration on the test results. We conducted a clinical study that aimed to elucidate whether sample refrigeration for 48 h affects QFT-Plus test results. We collected 2 blood samples each from 40 participants for QFT-Plus; one sample was refrigerated before incubation for QFT-Plus assay, while the other sample was incubated soon after collection and treated as control. After comparing QFT-Plus test results of refrigerated samples and control samples, the concordance rate and kappa coefficient between them were 95% and 0.90, respectively. Thus, blood samples for QFT-Plus test can be refrigerated for 48 h in lithium-heparin tubes without influencing the test results.

CD4+ T cell activation and associated susceptibility to HIV-1 infection in vitro increased following acute resistance exercise in human subjects

Early studies in exercise immunology suggested acute bouts of exercise had an immunosuppressive effect in human subjects. However, recent data, show acute bouts of combined aerobic and resistance training increase both lymphocyte activation and proliferation. We quantified resistance exercise-induced changes in the activation state of CD4+ T lymphocytes via surface protein expression and using a medically relevant model of infection (HIV-1). Using a randomized cross-over design, 10 untrained subjects completed a control and exercise session. The control session consisted of 30-min seated rest while the exercise session entailed 3 sets × 10 repetitions of back squat, leg press, and leg extensions at 70% 1-RM with 2-min rest between each set. Venous blood samples were obtained pre/post each session. CD4+ T lymphocytes were isolated from whole blood by negative selection. Expression of activation markers (CD69 & CD25) in both nonstimulated and stimulated (costimulation through CD3+ CD28) cells were assessed by flow cytometry. Resistance exercised-induced effects on intracellular activation was further evaluated via in vitro infection with HIV-1. Nonstimulated CD4+ T lymphocytes obtained postexercise exhibited elevated CD25 expression following 24 h in culture. Enhanced HIV-1 replication was observed in cells obtained postexercise. Our results demonstrate that an acute bout of resistance exercise increases the activation state of CD4+ T lymphocytes and results in a greater susceptibility to HIV-1 infection in vitro. These findings offer further evidence that exercise induces activation of T lymphocytes and provides a foundation for the use of medically relevant pathogens as indirect measures of intracellular activation.

Strength Training Session Induces Important Changes on Physiological, Immunological, and Inflammatory Biomarkers

Strength exercise is a strategy applied in sports and physical training processes. It may induce skeletal muscle hypertrophy. The hypertrophy is dependent on the eccentric muscle actions and on the inflammatory response. Here, we evaluate the physiological, immunological, and inflammatory responses induced by a session of strength training with a focus on predominance of the eccentric muscle actions. Twenty volunteers were separated into two groups: the untrained group (UTG) and the trained group (TG). Both groups hold 4 sets of leg press, knee extensor, and leg curl at 65% of personal one-repetition maximum (1RM), 90 s of recovery, and 2^″conc/3^″eccen of duration of execution in each repetition. Blood samples were collected immediately before and after, 2 hours after, and 24 h after the end of the exercise session. The single session of strength training elevated the heart rate (HR), rating of perceived exertion (RPE), visual analog scale (VAS), and lactate blood level in UTG and TG. Creatine kinase (CK) levels were higher at 2 and 24 h after the end of the exercise in UTG and, in TG, only at 24 h. The number of white blood cells (WBC) and neutrophils increased in UTG and TG, post and 2 h after exercise. Lymphocytes increased postexercise but reduced 2 h after exercise in both groups, while the number of monocytes increased only immediately after the exercise session in UTG and TG. The strength training session elevated the levels of apelin and fatty acid-binding proteins-3 (FABP3) in both groups and brain-derived neurotrophic factor (BDNF) in TG. The single exercise session was capable of inducing elevated HR, RPE, lactate level, and CK levels. This protocol changed the count/total number of circulating immune cells in both groups (UTG and TG) and also increased the level of plasmatic apelin, BDNF, and FLTS1 only in TG and FABP3 myokines in both groups.

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.