Central stimulation of hormone release and the proliferative response of lymphocytes in humans

Importance of temperature on immuno-metabolic regulation and cancer progression

Cancer immunotherapies emerge as promising strategies for restricting tumour growth. The tumour microenvironment (TME) has a major impact on the anti-tumour immune response and on the efficacy of the immunotherapies. Recent studies have linked changes in the ambient temperature with particular immuno-metabolic reprogramming and anti-cancer immune response in laboratory animals. Here, we describe the energetic balance of the organism during change in temperature, and link this to the immune alterations that could be of relevance for cancer, as well as for other human diseases. We highlight the contribution of the gut microbiota in modifying this interaction. We describe the overall metabolic response and underlying mechanisms of tumourigenesis in mouse models at varying ambient temperatures and shed light on their potential importance in developing therapeutics against cancer.

Electrical weapons, hematocytes, and ischemic cardiovascular accidents

BACKGROUND

There have been case reports following the use of a conducted electrical weapon (CEW) suggesting that these devices might affect coagulation or thrombosis in at-risk individuals. The aim of this manuscript therefore is firstly to explore this hypothesis by reviewing each of these cases and secondly to report the results of a prospective study exploring a priori the effects of electrical weapons on hematocytes in a group of human volunteers.

METHODS

First, we systematically reviewed all cases of adverse outcomes following CEW discharge that could be due to an effect on coagulation or thrombosis, with particular focus on the clinical scenario and its relationship with the weapon discharge. Second, we assessed hematocyte levels in venous blood from 29 volunteers before, 5 min after, and 24 h after receiving a full-trunk 5-s TASER® X26(E) CEW exposure.

RESULTS

Following extensive review of the literature, we found 3 relevant case reports of possible vascular thromboembolic clinical events after CEW exposure, specifically a case of ischemic stroke, and 2 cases of ST-segment elevation myocardial infarctions. Review of these published cases failed to establish a plausible linkage to the CEW beyond a temporal association with significant emotional and physiological stress from a violent struggle. Our prospective study of biomarker change following CEW discharge revealed acutely increased values for WBC (white blood cells), specifically lymphocytes and monocytes, and a raised platelet count. Neutrophil levels decreased as a percentage of WBC. While these changes were statistically significant at 5 min, all results remained within established reference ranges. At 24 h, all values had returned to baseline except total WBC which decreased to slightly below baseline but was still within the normal reference range.

CONCLUSIONS

A review of clinical cases, of ischemic or thrombotic events revealed no direct association with the CEW discharge. A full-trunk electrical weapon exposure did not lead to hematocyte changes beyond normal clinically expected variations in similar acute response scenarios. The case report and biomarker data do not support the hypothesis that a CEW discharge is associated with changes likely to promote coagulation or thrombus formation.

Blunted cortisol response to psychosocial stress in atopic patients is associated with decrease in salivary alpha-amylase and aldosterone: Focus on sex and menstrual cycle phase

A decreased responsiveness of the hypothalamic-pituitary-adrenocortical axis to stress stimuli in patients with atopy is well documented. The aim of this study was to investigate personality traits, salivary alpha-amylase activity and the aldosterone response to psychosocial stress procedure based on public speech in atopic patients with respect to sex and the menstrual cycle (MC) phase. The study was performed in 106 subjects of both sexes, 53 atopic patients suffering from allergic rhinitis, allergic asthma or atopic dermatitis and 53 age-, sex-, the MC phase- and BMI- matched healthy controls. Substantially attenuated activity of alpha-amylase and reduced secretion of aldosterone during the psychosocial stress were observed in the whole sample of patients with atopy. Higher activity of alpha-amylase observed in the follicular compared to the luteal phase in healthy women was not present in atopic patients. In both males and females, atopy was associated with blunted cortisol response but no changes in the heart rate. Psychological characterization revealed a significantly higher trait anxiety and higher preference for avoidance-oriented coping strategy in female but not male atopic patients. These findings provide evidence that patients with atopy exhibit insufficient alpha-amylase and aldosterone responsiveness to psychosocial stress, thus suggesting decreased sympathetic activity. Potential disturbances in sex hormone status during the MC in female patients with atopy have to be considered in future research. Changes in personality traits were demonstrated in female atopic patients, but not in male patients.

The effects of cold exposure on leukocytes, hormones and cytokines during acute exercise in humans

The purpose of the study was to examine the effects of exercise on total leukocyte count and subsets, as well as hormone and cytokine responses in a thermoneutral and cold environment, with and without an individualized pre-cooling protocol inducing low-intensity shivering. Nine healthy young men participated in six experimental trials wearing shorts and t-shirts. Participants exercised for 60 min on a treadmill at low (LOW: 50% of peak VO2) and moderate (MOD: 70% VO2peak) exercise intensities in a climatic chamber set at 22°C (NT), and in 0°C (COLD) with and without a pre-exercise low-intensity shivering protocol (SHIV). Core and skin temperature, heart rate and oxygen consumption were collected continuously. Blood samples were collected before and at the end of exercise to assess endocrine and immunological changes. Core temperature in NT was greater than COLD and SHIV by 0.4±0.2°C whereas skin temperature in NT was also greater than COLD and SHIV by 8.5±1.4°C and 9.3±2.5°C respectively in MOD. Total testosterone, adenocorticotropin and cortisol were greater in NT vs. COLD and SHIV in MOD. Norepinephrine was greater in NT vs. other conditions across intensities. Interleukin-2, IL-5, IL-7, IL-10, IL-17, IFN-γ, Rantes, Eotaxin, IP-10, MIP-1β, MCP-1, VEGF, PDGF, and G-CSF were elevated in NT vs. COLD and/or SHIV. Furthermore, IFN-γ, MIP-1β, MCP-1, IL-10, VEGF, and PDGF demonstrate greater concentrations in SHIV vs. COLD, mainly in the MOD condition. This study demonstrated that exercising in the cold can diminish the exercise-induced systemic inflammatory response seen in a thermoneutral environment. Nonetheless, prolonged cooling inducing shivering thermogenesis prior to exercise, may induce an immuno-stimulatory response following moderate intensity exercise. Performing exercise in cold environments can be a useful strategy in partially inhibiting the acute systemic inflammatory response from exercise but oppositely, additional body cooling may reverse this benefit.

Dietary nucleotide improves markers of immune response to strenuous exercise under a cold environment

Background

Strenuous exercise has been classically associated to immune-suppression and consequently to an increased risk of infections, especially at the upper respiratory tract. The administration of dietary nucleotides has been demonstrated useful to maintain the immune function in situations of stress and thus could be an appropriate strategy to counteract the decline of the immune function associated to strenuous exercise. The aim of the present study was to asses the impact of a specific nucleotide formulation (Inmunactive®) on the markers of immune function of athletes after a heavy exercise bout under cold conditions.

Methods

Twenty elite male taekwondo athletes were randomly divided into two groups of 10 subjects that were supplemented with placebo (P) or Inmunactive (I) at 480 mg/day during 30 days. At baseline (day 0) and after 4 wk of supplementation (day 30) each subject undertook an exhaustion exercise test using a cycloergometer. Skin temperature, core temperature, heart rate, lactate concentration and rating of perceived exertion (RPE) were recorded during the test. Blood and saliva samples were obtained before and after each exercise test for determination of blood cell concentrations, PHA-stimulated lymphocyte proliferation (PHA-LP) and salivary immunoglobulin A (SIgA).

Results

Exercise tests induced neutrophilia and reduction in lymphocyte blood counts on day 0 and on day 30 in both groups. However, the I group exhibited a faster recovery from the lymphopenic response than the P group, so that lymphocyte levels were higher after 150 min (P < 0.0028). Furthermore, the lymphoproliferative response was modulated by nucleotide supplementation, since it was higher in the I group on day 30 despite an almost significant (P < 0.06) exercise-evoked decrease at baseline.

Conclusions

These findings suggest that supplementation with a nucleotide-based product for 4 weeks could counteract the impairment of immune function after heavy exercise.

Ship-borne journey induces Th1 cytokines level in antarctic summer expeditioners

It has become apparent that extreme environmental conditions of Antarctic continent alters many immune responses. The present study was conducted on 28th Indian Antarctic expeditioners. The investigations were carried out to explore the effect of multiple stresses like isolation, cold and UV exposure on human immunity. Thirty blood samples were collected between 6 and 7 AM, after an overnight fast at different stages of the expedition - viz. the pre-exposure sample was collected at Delhi on 25(th) October 2008. The expedition started its ship journey from Capetown, on 6(th) January, 2009 and on-board blood was collected on 31(st) January 2009. After 1 month stay at Maitri, blood was collected on 3(rd) March 2009. Different parameters studied included levels of cytokines, chemokines and cortisol. The ship-borne journey induced a dramatic increase in TNF-α, IFN-γ, and B cell activating factor (BAFF) levels and moderate decreases in TGF-β and cortisol levels. However, after being off board for 1 month at Maitri station, levels of above cytokines, cortisol and BAFF were decreased but MIP-1α was significantly increased. These data for the first time suggest that ship-borne journey to the Antarctic continent results in tremendous stress to the body, which eventually resulted in increased TH1-biased immunity.

The immunomodulatory effects of clonidine, an α-2-adrenergic agonist, in laying hens

The ability of the sympathetic nervous system to regulate chicken immune function was examined. Clonidine, an alpha-2 adrenergic receptor agonist, was administrated at 2.5, 5.0, or 10.0 mg/L in the drinking water of White Leghorn hens at 48 wk of age. The hens were randomly housed in conventional cages in pairs. Concentrations of plasma IgG (also named IgY) were detected using chicken IgG ELISA, and the percentage of subpopulations of circulating lymphocytes were analyzed using flow cytometry. Compared with controls, treated hens had higher circulating IgG levels and a greater percentage of circulating B cells (Bu-1+ cells, P < 0.01) after 1 wk of treatment. Additionally, the percentages of CD8+ cells were consistently higher (P = 0.07) in the treated hens compared with controls, whereas the percentages of CD4+ cells and the ratio of CD4+ cell to CD8+ cell were not affected by the treatment (P > 0.05). These effects of clonidine on the IgG concentrations and the proportions of B-cells and CD8+ cells were dose-related. The highest increase was found in the hens treated with 10.0 mg/L of clonidine. These results suggest that the sympathetic nervous system is directly involved in regulating the chicken immune system via regulation of alpha-2-adrenergic receptor activations.

TH1-biased immunity induced by exposure to Antarctic winter

BACKGROUND

Certain immune functions are known to be impaired in human beings exposed to Antarctic winter; in particular, decreased amounts of serum proinflammatory cytokines, such as TNF-alpha and IL-1, were noted. It is not known, however, whether this exposure has any effect on T-cell-mediated acquired immune functions.

OBJECTIVES

This study aims to investigate whether exposure to Antarctic winter has any effect on T cell-dependent immune functions.

METHODS

We assessed changes in various immunologic indicators, including serum levels of various cytokines, peripheral blood Valpha24Vbeta11 natural killer T cell numbers, and T(H)1/T(H)2 ratios of 40 Japanese personnel exposed to an Antarctic winter. Also, a 2-month inland traverse was executed during the isolation, and the effect on the above indicators was assessed.

RESULTS

All subjects were healthy during the Antarctic isolation. The levels of serum TNF-alpha, IL-1Ra, IL-6, and IL-1beta were dramatically reduced and remained at low levels throughout the isolation. The decrease in the levels of TNF-alpha and IL-1Ra was more pronounced during the inland traverse than during the rest of the isolation. The percentage of Valpha24Vbeta11 natural killer T cells was significantly increased at the midpoint of the isolation. Most interestingly, T(H)1/T(H)2 ratio was increased significantly, and this T(H)1 bias was most prominent at the late point of the isolation.

CONCLUSIONS

Exposure to an Antarctic winter appeared to induce T(H)1-skewed immunity in human beings.

Cold exposure: human immune responses and intracellular cytokine expression

It is commonly believed that exposure to cold environmental temperatures depresses immune function and increases the risk for infection. This review paper will 1) present an overview of human physiological responses to cold exposure, 2) present the human studies examining the effects of cold exposure on immune responses, and 3) summarize recent experiments from our laboratories examining the effects of exercise and fatigue on immune responses during subsequent cold exposure. Based on the review of the literature, there is no support for the concept that cold exposure depresses immune function.

Immune changes in humans during cold exposure: effects of prior heating and exercise

This study examined the immunological responses to cold exposure together with the effects of pretreatment with either passive heating or exercise (with and without a thermal clamp). On four separate occasions, seven healthy men [mean age 24.0 +/- 1.9 (SE) yr, peak oxygen consumption = 45.7 +/- 2.0 ml. kg(-1). min(-1)] sat for 2 h in a climatic chamber maintained at 5 degrees C. Before exposure, subjects participated in one of four pretreatment conditions. For the thermoneutral control condition, subjects remained seated for 1 h in a water bath at 35 degrees C. In another pretreatment, subjects were passively heated in a warm (38 degrees C) water bath for 1 h. In two other pretreatments, subjects exercised for 1 h at 55% peak oxygen consumption (once immersed in 18 degrees C water and once in 35 degrees C water). Core temperature rose by 1 degrees C during passive heating and during exercise in 35 degrees C water and remained stable during exercise in 18 degrees C water (thermal clamping). Subsequent cold exposure induced a leukocytosis and granulocytosis, an increase in natural killer cell count and activity, and a rise in circulating levels of interleukin-6. Pretreatment with exercise in 18 degrees C water augmented the leukocyte, granulocyte, and monocyte response. These results indicate that acute cold exposure has immunostimulating effects and that, with thermal clamping, pretreatment with physical exercise can enhance this response. Increases in levels of circulating norepinephrine may account for the changes observed during cold exposure and their modification by changes in initial status.

Reduced catecholamine response of lymphocytes from patients with rheumatoid arthritis

Catecholamines modulate lymphocyte function via stimulation of beta2-adrenergic receptors (beta2R). Previous investigations revealed a decreased density of beta2R on peripheral blood mononuclear cells (PBMC) in patients with chronic rheumatic diseases. Aim of the present study was to determine the impact of this decrease on catecholamine response of PBMC from patients with rheumatoid arthritis (RA) in vitro. PBMC from 17 patients with RA and 12 healthy blood donors (HD) were investigated. Beta2R were determined by a radioligand binding assay. The effects of epinephrine (E) and norepinephrine (NE) on PBMC proliferation were studied using cells activated with pokeweed mitogen (PWM) and monoclonal anti-CD3-antibodies (OKT3), respectively. In parallel, alpha1- or beta-receptor antagonist were added to the culture to determine the specificity of the catecholaminergic effects. The results showed that depending on the stimulus and the catecholamine concentration employed E and NE exert inhibitory (OKT3) or stimulatory signals (PWM) on lymphocyte proliferation. Inhibitory effects could be abolished by adding beta-antagonist, while stimulatory signals were diminished after addition of alpha1- of beta-antagonist. Patients with RA showed a significantly reduced density of beta2R compared to HD paralleled by a significantly reduced influence of catecholamines on lymphocyte function. The study demonstrates the intricate relationship between PBMC reactivity and catecholamine effects that are mediated via alpha1- and beta-adrenergic receptors. In this respect the reduced catecholamine response of PBMC from RA patients may contribute to the pathogenic process of RA.