Effects of stress on the immune system

Thyroid hormones as modulators of immune activities at the cellular level

BACKGROUND

Increasing evidence suggests that thyroid hormones, L-thyroxine (T(4)) and 3,3',5-triiodo-L-thyronine (T(3)), are modulators of the immune response. In monocytes, macrophages, leukocytes, natural killer cells, and lymphocytes, a wide range of immune functions such as chemotaxis, phagocytosis, generation of reactive oxygen species (ROS), and cytokine synthesis and release are altered under hypo- and hyperthyroid conditions.

SUMMARY

Hyperthyroidism decreases the proinflammatory activities of monocytes and macrophages, whereas enhancement of phagocytosis and increased levels of ROS may occur during hypothyroidism. The expression of proinflammatory molecules such as macrophage inflammatory protein-1α and interleukin-1β increases in hypothyroidism. However, in Kupffer cells, proinflammatory activities such as the respiratory burst, nitric oxide synthase activity, and tumor necrosis factor-α expression may result from increased T(3) levels. Thyroid hormones also affect natural killer cell activity and cell-mediated immune responses. Still, for many immune cells no clear correlation has been found so far between abnormally high or low T(3) or T(4) levels and the effects observed on the immune responses.

CONCLUSIONS

In this review we outline the contributions of thyroid hormones to different aspects of innate and adaptive immune responses. The relationship between thyroid hormones and immune cells is complex and T(3) and T(4) may modulate immune responses through both genomic and nongenomic mechanisms. Future studies of the molecular signaling mechanisms involved in this cross-talk between thyroid hormones and the immune system may support development of new strategies to improve clinical immune responses.

Serum levels of immunoglobulins (IgG, IgA, IgM) in Antarctic summer expeditioners and their relationship with seasickness

The Antarctic continent is full of environmental extremes like isolation, cold, UV exposure, and blizzards etc. The present study was conducted to analyze the effect of ship borne journey and the impact of Antarctic harsh environment on serum immunoglobulin (IgG, IgM, IgA) levels and their relationship with seasickness in Indian expeditioners. It was observed that one month onboard ship journey induced an increase in serum IgA levels and decrease in IgG levels while after being one month off board at the Indian research station Maitri, decreased levels of IgG and increased levels of IgA were found. IgM levels were not altered in comparison to the base line control. Moreover, serum IgG level showed a positive correlation while IgA level showed a negative correlation with seasickness. The stimulation of human peripheral blood mononuclear cells (PBMCs) with serum of expeditioner at different places showed that IgA at lower dose induces the release of pro-inflammatory IL-1β, and IL-6 cytokines from PBMCs while higher dose of IgA decreases proinflammatory cytokine production. The release of anti-inflammatory cytokines TGF-β1 and IL-10 was not significantly altered. Thus, the present study concluded that ship borne journey and Antarctic environment lead to increased serum IgA levels while decreased IgG levels. It also suggests that serum IgA level could be a possible biomarker for environmental stress.

Molecular and serological prevalence of Babesia bovis and Babesia bigemina in water buffaloes in the northeast region of Thailand

Bovine babesiosis is a tick-transmitted hemoprotozoan disease that is mainly caused by Babesia bovis and Babesia bigemina and is characterized by significant morbidity and mortality worldwide. The disease is widespread in the northeastern region of Thailand, where an increasingly large part of the livestock is composed of water buffaloes. The present study was therefore conducted to investigate the epidemiological distribution of B. bovis and B. bigemina in water buffaloes in the northeastern region of Thailand. A total of 305 buffalo blood samples were randomly collected from five provinces and simultaneously analyzed by the nested PCR (nPCR) assay, ELISA, and IFAT techniques. The overall prevalence of B. bovis and B. bigemina was 11.2% and 3.6% by nPCR, 14.7% and 5.9% by ELISA, and 16.8% and 5.6% by IFAT, respectively. The high concordance between the molecular and the serological detection tests revealed the specificity and sensitivity of the diagnostic assays used for the detection of infection as well as the endemic stability status of the parasites in the surveyed areas. Statistically significant differences in the prevalence of the two infections were observed on the basis of age and location but not gender. Our data provide valuable information regarding the epidemiology of B. bovis and B. bigemina infection in water buffaloes in the northeastern region of Thailand which will likely be very beneficial for management and control programs of this disease.

Endocrine cells of the adenohypophysis in severe acute respiratory syndrome (SARS)

It is known that severe acute respiratory syndrome (SARS), a severe infectious illness, which caused an epidemic in Asia in 2003, has extensive and complex effects on human organ systems. It has been reported that the serum levels of prolactin (PRL), follicle stimulating hormone (FSH), and luteinizing hormone (LH) of SARS patients are significantly higher than those of control groups, while estradiol (E2), pregnancy hormone (P), and thyroid stimulating hormone (TSH) are considerably lower than those of normal controls. This phenomenon suggests that the adenohypophyseal endocrine cells in SARS patients may be damaged. However, up to now there has been no direct histological investigation on the endocrine cells of patients' pituitary. Here we investigated the endocrine cells in the adenohypophysis obtained from autopsies of 5 SARS patients. The immunohistochemistry and quantitative image results showed that compared with control cases, both the number of positive cells and the staining intensity of immunoreactivity for growth hormone, TSH, and adrenocorticotrophic hormone in these cells were remarkably decreased, while that of PRL, FSH, and LH were significantly increased in all SARS cases studied. These findings indicated that alterations occurred in the patients' adenohypophyseal endocrine cells, and these changes were consistent with the serum levels of relevant endocrine hormones reported previously. It appears that changes in these endocrine cells and their hormones are affected by the severity of this new infectious disease.

Anti-stress effects of ginseng via down-regulation of tyrosine hydroxylase (TH) and dopamine β-hydroxylase (DBH) gene expression in immobilization-stressed rats and PC12 cells

Catecholamines are among the first molecules that displayed a kind of response to prolonged or repeated stress. It is well established that long-term stress leads to the induction of catecholamine biosynthetic enzymes such as tyrosine hydroxylase (TH) and dopamine β-hydroxylase (DBH) in adrenal medulla. The aim of the present study was to evaluate the effects of ginseng on TH and DBH mRNA expression. Repeated (2 h daily, 14 days) immobilization stress resulted in a significant increase of TH and DBH mRNA levels in rat adrenal medulla. However, ginseng treatment reversed the stress-induced increase of TH and DBH mRNA expression in the immobilization-stressed rats. Nicotine as a ligand of the nicotinic acetylcholine receptor (nAChR) in adrenal medulla stimulates catecholamine secretion and activates TH and DBH gene expression. Nicotine treatment increased mRNA levels of TH and DBH by 3.3- and 3.1-fold in PC12 cells. The ginseng total saponin exhibited a significant reversal in the nicotine-induced increase of TH and DBH mRNA expression, decreasing the mRNA levels of TH and DBH by 57.2% and 48.9%, respectively in PC12 cells. In conclusion, immobilization stress induced catecholamine biosynthetic enzymes gene expression, while ginseng appeared to restore homeostasis via suppression of TH and DBH gene expression. In part, the regulatory activity in the TH and DBH gene expression of ginseng may account for the anti-stress action produced by ginseng.

Does caffeine reverse the EAC cell-induced immune suppression?

The aim of this study was to investigate the effect of long-term consumption of caffeine in the development of Ehrlich ascites carcinoma (EAC) cells in adult female mice, 25–30 g, in relation to immune response. Mice were treated with caffeine (20 mg kg−1 daily, p.o.) for 22–27 consecutive days or inoculated with EAC cells (5 times 106 cells/mL, i.p.), or both. Control mice, corresponding to experimental groups, were treated with corresponding vehicles under similar conditions. The lymphocyte viability, mitogen-induced proliferating activity, cytotoxicity and DNA fragmentation from blood, spleen and thymus of both control and experimental groups were measured as immune response parameters. An immune response index, corticosterone, was also measured in adrenals and plasma under similar conditions. Results showed that development of EAC cells caused immune suppression with a reduction of lymphocyte viability, cytotoxicity and proliferative activity and induction of DNA fragmentation in those tissues, as well as an increase in plasma corticosterone. Though long-term caffeine treatment (which resulted in tolerance to caffeine) alone did not alter significantly any of the immune response parameters studied, including corticosterone status (immune biomarker), the continuation of caffeine treatment during the development of EAC cells either restored or reduced the EAC cell-induced alteration in these parameters, including the HPA axis biomarker. These results suggest that long-term caffeine intake may inhibit or reverse the EAC cell-induced immune suppression.

Phagocytic responses of peritoneal macrophages and neutrophils are different in rats following prolonged exercise

OBJECTIVE

To analyze the effects of exhausting long-duration physical exercise (swimming) sessions of different durations and intensities on the number and phagocytic capacity of macrophages and neutrophils in sedentary rats.

INTRODUCTION

Exercise intensity, duration and frequency are important factors in determining immune response to physical effort. Thus, the effects of exhausting long-duration exercise are unclear.

METHODS

Wistar rats were divided into two groups: an untreated group (macrophage study) and oyster glycogen-treated rats (neutrophil study). In each group, the animals were subdivided into five groups (10 rats per group): unexercised controls, an unadapted low-intensity exercise group, an unadapted moderate-intensity exercise group, a preadapted low-intensity exercise group and a preadapted moderate-intensity exercise group. All exercises were performed to exhaustion, and preadaptation consisted of 5, 15, 30 and 45 min sessions.

RESULTS

Macrophage study: the number of peritoneal macrophages significantly decreased (9.22 ± 1.78 x 10(6)) after unadapted exercise but increased (21.50 ± 0.63 x 10(6)) after preadapted low-intensity exercise, with no changes in the moderate-intensity exercise group. Phagocytic capacity, however, increased by more than 80% in all exercise groups (low/moderate, unadapted/preadapted). Neutrophil study: the number of peritoneal neutrophils significantly decreased after unadapted (29.20 ± 3.34 x 10(6)) and preadapted (50.00 ± 3.53 x 10(6)) low-intensity exercise but increased after unadapted (127.60 ± 5.14 x 10(6)) and preadapted (221.80 ± 14.85 x 10(6)) moderate exercise. Neutrophil phagocytic capacity decreased by 63% after unadapted moderate exercise but increased by 90% after corresponding preadapted sessions, with no changes in the low-intensity exercise groups.

CONCLUSION

Neutrophils and macrophages of sedentary rats respond differently to exercise-induced stress. Adaptation sessions reduce exercise-induced stress on the immune system.

The influence of long term sound stress on histological structure of immune organs in broiler chickens

The aim of this paper was to examine the effect of different duration sound stress on immune organs of broiler chickens of different age. Nine groups, with 10 chickens in each group were included in experiment. The histological structure of bursa of Fabricius, thymus, and spleen were analyzed. The results indicated that the bursa of Fabricius, in relation to the other examined organs, was the most sensitive to this kind of stress. Histological changes of spleen and thymus were also observed, but less prominent except in chickens after more than 30 days of exposure to stress. According to our results, degree of histological changes of immune organs under the influence of sound stress depends on the length of exposure and age of chickens.

Probiotics: multifarious oral vaccine against infectious traumas

Microorganisms have been used for a long time in food and alcoholic fermentation. In the last few years they have undergone scientific scrutiny of their preventative and therapeutic aspects. This has led to the discovery of a new term, probiotics. Lactic acid bacteria (LAB) are microbial communities normally present in the intestine of most animals. They play an important role in humans and other animals, and act as immunomodulators. They are helpful in the treatment and prevention of disease as well as improving the digestion and absorption of nutrients. Probiotic microorganisms include the LAB Lactobacillus acidophilus, Lactobacillus bulgaricus, Lactobacillus casei, Lactobacillus plantarum and Lactobacillus rhamnosus. Use of these live bacteria to elicit an immune response or to carry a vaccine component is a new invention in vaccine development. The advantage of live bacterial vaccines is that they mimic natural infection, have intrinsic adjuvant properties and can be given orally. Components of pathogenic and nonpathogenic food-related microorganisms are currently being evaluated as candidates for oral vaccines.

Long-term effect of continuous positive airway pressure therapy on inflammation markers of patients with obstructive sleep apnea syndrome

STUDY OBJECTIVES

Several lines of evidence suggest immune system derangement in obstructive sleep apnea syndrome (OSAS) patients. However, no data exist on the long-term effect of continuous positive airway pressure (CPAP) treatment on systemic immunity. Hence, we sought to evaluate this effect on various immunological parameters in OSAS patients.

DESIGN

Prospective case series.

SETTING

Sleep unit of a general hospital.

PATIENTS

Newly-diagnosed, nonsmoking, otherwise healthy OSAS male patients (n = 52) were evaluated on diagnosis and 6 months after CPAP treatment. According to compliance to CPAP use at 6-month follow-up, they were divided into 2 groups: group A (n = 32): good compliance (mean CPAP use > or = 4 h/night); and group B (n = 20): poor compliance (mean CPAP use < 4 h/night).

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

Blood samples were obtained at baseline and at the 6-month follow-up. Percentage and absolute count of lymphocyte subsets (by flow cytometry), serum TNF-alpha, IL-6, and uric acid levels were measured. No differences were recorded regarding the baseline anthropometric or sleep characteristics of the 2 groups. In group A, a significant decrease in the absolute count of total lymphocytes (P = 0.003), and of CD4+ cells (P = 0.001), and a decrease in TNF-alpha levels (P = 0.001) and uric acid levels (P < 0.001) was observed after CPAP application. On the contrary, no alterations occurred in any of the tested parameters in group B patients.

CONCLUSIONS

The selective reduction of soluble and cellular immune response factors only in those OSAS patients who exhibited good compliance to CPAP therapy provides further evidence for an ongoing systemic immune process in OSAS.

Neuroimmunomodulation: Neuroendocrine Regulation of Immunity: The Effects of Noradrenaline inXenopus Laevis, the South African Clawed Toad

A functional association between the peripheral nervous and the immune system in Xenopus laevis, the South African clawed toad, is demonstrated. This association involves the neurotransmitter noradrenaline (NA), produced and released by the sympathetic nerves of the spleen. Chemical sympathectomy prior to immunization reduces splenic NA, and decreases thymus-dependent (TD), but increases thymus-independent (TI), antibody responses. Immune challenge with representatives of the three antigen classes affects splenic NA levels differentially. Thus, the modulatory effect of NA on immunity will depend on the immunogen used. Carrier-priming of helper function in TD responses stimulates a transitory NA release in the spleen, while subsequent immunization activates a more prolonged release. The two types of challenge differ in the antigenic dose given. The effects of NA also depend on the time when it is applied. If used early in the in vivo TD response, antibody production is increased, but if given later, suppressor function is stimulated, thus decreasing antibody production. NA increases both amplifying and suppressing T cell functions in TD responses through stimulation of the alpha 2 adrenoceptor. Alpha 2 adrenoceptor stimulation decreases, and beta adrenoceptor stimulation increases, anti-TNP reactivity. Since an alpha 2 receptor agonist does not affect lectin-stimulated T cell mitogenesis, while a beta receptor agonist depresses it, NA appears to up-regulate T cell functions by affecting their maturation, rather than their clonal expansion.

The immunological and metabolic responses to exercise of varying intensities in normoxic and hypoxic environments

The purpose of this study was to determine the effects of varying intensities of exercise in normoxic and hypoxic environments on selected immune regulation and metabolic responses. Using a within-subjects design, subjects performed maximal tests on a cycle ergometer in both normoxic (PiO2 = 20.94%) and hypoxic (PiO2 = 14.65%) environments to determine [latin capital V with dot above]O2max. On separate occasions, subjects then performed four randomly assigned, 1-hour exercise bouts on a cycle ergometer (two each in normoxic and hypoxic environments). The hypoxic environment was created by reducing the O2 concentration of inspired air using a commercially available hypoxic chamber. The intensities for the exercise bouts were predetermined as 40 and 60% of their normoxic [latin capital V with dot above]O2max for the normoxic exercise bouts and as 40 and 60% of their hypoxic [latin capital V with dot above]O2max for the hypoxic exercise bouts. Blood samples were collected preexercise, postexercise, 15 minutes postexercise, 2 hours postexercise, and 24 hours postexercise for the determination of interleukin-1 (IL-1), tumor necrosis factor-[alpha] (TNF-[alpha]), glucose, glycerol, free fatty acids, epinephrine, norepinephrine, and cortisol. There were no significant differences (p < 0.05) between condition or intensity for IL-1 or TNF-[alpha]. Significant differences (p < 0.05) between intensities were demonstrated for epinephrine, norepinephrine, and cortisol (p < 0.05). A significant difference was identified between normoxic and hypoxic environments with respect to nonesterifed fatty acids (0.45 +/- 0.37 vs. 0.58 +/- 0.31 mEq x L-1, respectively; p = 0.012). During prolonged exercise at 40 and 60% of their respective [latin capital V with dot above]O2max values, hypoxia did not seem to dramatically alter the response of the selected immune system or metabolic markers. Exercise training that uses acute hypoxic environments does not adversely affect immune regulation system status and may be beneficial for those individuals looking to increase endurance performance.

Expression and distribution of heat shock proteins in the heart of transported pigs

The expression and localization of four heat shock proteins (Hsp70, Hsp86, Hsp90, and Hsp27) were shown in the heart tissue of pigs transported for 6 h. Immunostaining detected the consistent presence of all Hsps in the pig myocardial cells under both transported and normal housing conditions. Immunohistochemical analysis revealed predominance of Hsp70 (significantly highest levels) and Hsp27 in the cytoplasm of myocardial cells. Hsp90 and Hsp86 were expressed both in the cytoplasm and in the nucleus, preferentially in the cytoplasm, of the myocardial cells. In view of their abundant and uniform distributions in the myocardial cells, the expression and distribution patterns of all detected Hsps within the myocardial cells, mostly limited to the cytoplasm, could be related to their chaperone function for cells with important special activities in this study. The identification of all four Hsps in the blood vessel endothelial cells possibly implies that endothelial cells react to ischemia and hypoxia by expressing Hsps. Immunoblot findings suggest that the level of all Hsps decreased in response to stress due to a 6 h journey. The decrease in Hsp levels in the myocardial cells may indicate that the transport stress may have overcharged the repair mechanisms of the cells. Whether this distinct depletion of Hsps contributes to an increased susceptibility to acute heart failure and the sudden death syndrome in transported pigs should be elucidated in future experiments.

Hematopoietic response of rats exposed to the impact of an acute psychophysiological stressor on responsiveness to an in vivo challenge with Listeria monocytogenes: modulation by Chlorella vulgaris prophylactic treatment

In this study, we investigated the hematopoietic response of rats pretreated with CV and exposed to the impact of acute escapable, inescapable or psychogenical stress on responsiveness to an in vivo challenge with Listeria monocytogenes. No consistent changes were observed after exposure to escapable footshock. Conversely, the impact of uncontrollable stress (inescapable and psychogenical) was manifested by an early onset and increased severity and duration of myelossuppression produced by the infection. Small size CFU-GM colonies and increased numbers of clusters were observed, concurrently to a greater expansion in the more mature population of bone marrow granulocytes. No differences were observed between the responses of both uncontrollable stress regimens. CV prevented the myelossuppression caused by stress/infection due to increased numbers of CFU-GM in the bone marrow. Colonies of cells tightly packed, with a very condensed nucleus; in association with a greater expansion in the more immature population of bone marrow granulocytes were observed. Investigation of the production of colony-stimulating factors revealed increased colony-stimulating activity (CSA) in the serum of normal and infected/stressed rats treated with the algae. CV treatment restored/enhanced the changes produced by stress/infection in total and differential bone marrow and peripheral cells counts. Further studies demonstrated that INF-gamma is significantly reduced, whereas IL-10 is significantly increased after exposure to uncontrollable stress. Treatment with CV significantly increased INF-gamma levels and diminished the levels of IL-10. Uncontrollable stress reduced the protection afforded by CV to a lethal dose of L. monocytogenes, with survival rates being reduced from (50%) in infected rats to 20% in infected/stressed rats. All together, our results suggest Chlorella treatment as an effective tool for the prophylaxis of post-stress myelossupression, including the detrimental effect of stress on the course and outcome of infections.

Psychoneuroimmunology

Psychoneuroimmunology (PNI) is a discipline that has evolved in the last 40 years to study the relationship between immunity, the endocrine system, and the central and peripheral nervous systems. In this manner, neurotransmitters, hormones, and neuropeptides have been found to regulate immune cells, and these in turn are capable of communicating with nervous tissue through the secretion of a wide variety of cytokines. Of critical importance is the effect of products of the CNS and nerves on the maintenance of the delicate balance between cell-mediated (Th1) and humoral (Th2) immune responses. A good example of how this concept operates in vivo becomes evident when analyzing the effects of stressors. Chronic stress affects significantly the function of the immune system as well as modifies the evolution of a variety of skin diseases, as psychosocial interventions have proved to be effective in their therapy.

Enhancing versus Suppressive Effects of Stress on Immune Function: Implications for Immunoprotection versus Immunopathology

It is widely believed that stress suppresses immune function and increases susceptibility to infections and cancer. Paradoxically, stress is also known to exacerbate allergic, autoimmune, and inflammatory diseases. These observations suggest that stress may have bidirectional effects on immune function, being immunosuppressive in some instances and immunoenhancing in others. It has recently been shown that in contrast to chronic stress that suppresses or dysregulates immune function, acute stress can be immunoenhancing. Acute stress enhances dendritic cell, neutrophil, macrophage, and lymphocyte trafficking, maturation, and function and has been shown to augment innate and adaptive immune responses. Acute stress experienced prior to novel antigen exposure enhances innate immunity and memory T-cell formation and results in a significant and long-lasting immunoenhancement. Acute stress experienced during antigen reexposure enhances secondary/adaptive immune responses. Therefore, depending on the conditions of immune activation and the immunizing antigen, acute stress may enhance the acquisition and expression of immunoprotection or immunopathology. In contrast, chronic stress dysregulates innate and adaptive immune responses by changing the type 1-type 2 cytokine balance and suppresses immunity by decreasing leukocyte numbers, trafficking, and function. Chronic stress also increases susceptibility to skin cancer by suppressing type 1 cytokines and protective T cells while increasing suppressor T-cell function. We have suggested that the adaptive purpose of a physiologic stress response may be to promote survival, with stress hormones and neurotransmitters serving as beacons that prepare the immune system for potential challenges (eg, wounding or infection) perceived by the brain (eg, detection of an attacker). However, this system may exacerbate immunopathology if the enhanced immune response is directed against innocuous or self-antigens or dysregulated following prolonged activation, as seen during chronic stress. In view of the ubiquitous nature of stress and its significant effects on immunoprotection and immunopathology, it is important to further elucidate the mechanisms mediating stress-immune interactions and to meaningfully translate findings from bench to bedside.

Effects of experimental increase of corticosterone levels on begging behavior, immunity and parental provisioning rate in house sparrows

Begging is a complex display that is supposed to honestly indicate the need for food of nestlings, and, usually, parents use this information to adjust their investment in food provisioning. However, the mechanisms that ensure the honesty of begging as an indicator of need are still poorly known. It has been shown that levels of corticosterone (Cort), the hormone released during the stress response, raises during food shortage and is associated with increased begging rate. However, Cort also entails costs and these costs might prevent nestlings cheating. We tested this hypothesis in nestlings of the house sparrow. We experimentally increased levels of circulating Cort and investigated (1) the behavioral responses of nestlings, (2) the parental allocation of food and (3) the consequences on nestling growth and immune response. We found that Cort significantly increased begging rate but did not affect posture and position in the nest. Surprisingly, when begging effort was controlled statistically, control nestlings received more food from parents than Cort-treated nestlings. We also found that nestlings injected with Cort showed a weaker immune response and had lower body mass than controls. We suggest that Cort might have affected multiple aspects of nestling signaling, such as mouth color, and that parents use these multiple signals to adjust their feeding effort.

Trypanosoma cruzi: Plasma corticosterone after repetitive stress during the acute phase of infection

An increased level of plasma corticosterone is one manifestation of severe environmental or physiologic stress. The stress response mediated by the hypothalamic-pituitary-adrenal axis is already known to suppress immunoglobulin production and to impair immune function, but there are few studies relating stress and plasma corticosterone to the outcome of Trypanosoma cruzi infection. In this study, male Wistar rats were infected with the Y strain of T. cruzi and then subjected to repetitive stress by exposure to ether vapor for 1min twice a day during the acute phase of infection. Stressed animals showed decreased lytic antibody activity and lowered levels of peritoneal macrophages. Despite an increase in the weight of the spleen, histological analyses demonstrated tissue alterations, the presence of amastigote nests, and a complete absence of activated lymphoid follicles. These results suggest that stress-induced increases in plasma corticosterone can suppress the immune response and worsen tissue injury during the acute phase of T. cruzi infection.

Posttraumatic growth, immunity and survival in patients with hepatoma

This study was designed to assess the relationship between posttraumatic growth (PTG), immunity, and survival in patients with biopsy-proven hepatocellular carcinoma (HCC). Forty-one patients with HCC were administered the Posttraumatic Growth Inventory. Total and differential peripheral blood leukocytes (PBL) counts were measured at baseline, 3-, and 6-month follow-up. Survival also was measured from the data of diagnosis to death. Participants who scored above the median for the PTGI total scale score (423 days) survived 186 days longer than participants who scored below the median PTGI total score (237 days). Patients with PTG scores above the median had higher PBL counts. The results of this study suggest that patients with greater PTG scores recover more rapidly from chemotherapy in regards to their white blood cell counts. Further research is warranted regarding the possible immune mediation between PTG and survival.

Differential Effects of Sex and Genetics on Behavior and Stress Response of Turkeys

Three lines of turkeys were tested for response in T-maze and open-field tests during the first 8 d after hatch, and behavior was observed after catching, moving, and transport. They were also compared for corticosterone (CORT) levels and heterophil:lymphocyte ratios (H:L) at 15 wk of age in response to an Escherichia coli challenge followed by transport stress. Large commercial-(COMM) line birds were faster and more active in the T-maze at d 2 than egg-line birds. Male COMM-line birds were faster than male egg-line birds when tested in an open field at d 8. Egg-line birds had more sleeping behavior after moving to a new floor pen as compared with both an intermediate-sized line (F line) and the COMM line. Transport stress increased CORT levels in all 3 lines, and the increase was greater in males compared with females. The egg line had higher basal CORT levels (P = 0.03) and higher levels after transport (P < 0.0001). The H:L ratios were affected by both transport stress and line but not by sex. The H:L ratio was lower in the egg line as compared with both the F line and the COMM line (P < 0.0001), with the COMM line having the greatest increase in response to transport. These data, combined with those from previous studies of these lines, suggest that differences in activity of fast-growing turkeys may be used to select birds that are less susceptible to inflammatory bacterial disease and that the H:L ratio may be more useful than serum CORT in evaluating the deleterious effects of stress.

Periparturient cortisol, acute phase cytokine, and acute phase protein profiles of gilts housed in groups or stalls during gestation

Use of gestation stalls in pork production remains a controversial topic in animal welfare. Immune status and measures are frequently used to assess stress levels and thus well-being of confined animals. The important welfare issue of close confinement among gestating gilts was tested by quantifying cortisol, acute phase cytokine, and acute phase protein pro-files before and after farrowing of gilts housed in 2 systems. Landrace x Yorkshire crossbred gilts housed in groups of 4 (group, n = 8) in pens (3.9 x 2.4 m with 4 individual feeding spaces, 9.36 m(2) total or 2.34 m(2)/gilt) were compared with gilts housed in standard industry stalls (stall, n = 16; 2.2 x 0.6 m, 1.32 m(2)/gilt). Floors were fully slatted, and a substrate was not provided for either system. Cortisol was determined from saliva on d 105 of gestation, 1 h after moving the gilts into farrowing stalls (d 111), and 24 h and 7 d after farrowing. Cortisol was greater (P = 0.04) for group gilts compared with stall gilts 1 h after moving them into farrowing stalls and 24 h after farrowing. Cortisol concentrations decreased (P = 0.001) over time. Leukocyte mRNA expression of IL-1, IL-1 receptor antagonist, and tumor necrosis factor-alpha was determined by quantitative, reverse transcription PCR on d 35, 63, and 91 of gestation and 72 h after farrowing. Cytokine mRNA expression of peripheral blood mononuclear cells did not differ between housing systems for IL-1, its receptor antagonist, or for tumor necrosis factor-alpha. Acute phase proteins, including fibrinogen, haptoglobin, and alpha(1)-acid glycoprotein were determined for plasma samples taken at d 35, 63, and 91 of gestation and 72 h and 14 d after farrowing. In contrast to cortisol, plasma fibrinogen concentrations increased (P < 0.005) over time. Haptoglobin did not differ between treatments (P > 0.10). Stall gilts tended to have greater (P = 0.07) plasma alpha(1)-acid glycoprotein concentrations than group animals at d 35 of gestation and d 14 after farrowing. These data showed a trend (P < 0.07) for alpha(1)-acid glycoprotein concentrations to return to baseline more quickly in group-housed gilts, which did not appear to be directly related to increased cortisol just before farrowing. In conclusion, few differences in the acute phase response were detected between housing systems, suggesting that the resting immunological responses are only mildly affected by gestation stalls.

Cortisol and immune measures in boars exposed to three-day administration of exogenous adrenocorticotropic hormone

The aim of the study was to evaluate the effect of adrenal stimulation by adrenocorticotropic hormone (ACTH) on blood cortisol concentration and on circulating total and differential leukocyte counts during and in the 16 days after ACTH administration. Swedish Landrace boars aged approximately 6-7 months were used. ACTH-treated animals (n = 7) were given ACTH intravenously at 10 microg/kg body mass for 3 days. A control group of animals (n = 7) received 1 ml of sterile 0.9% saline intramuscularly. ACTH induced a highly significant increase (p>0.0001) in serum cortisol in treated boars. On the day after the last ACTH dose, the cortisol concentration was significantly higher, but the level of significance was lower than during ACTH administration (p>0.05). During ACTH treatment, a significant increase was recorded in total leukocyte count and neutrophil percentage (p>0.05 to p>0.0001), along with the increase in blood cortisol concentration, whereas percentage lymphocyte count showed a significant decrease. Lymphopenia disappeared upon cessation of treatment, but neutropenia developed in the week after treatment. On all three days of ACTH challenge, the neutrophil-to-lymphocyte ratio was significantly increased. An increase in eosinophil percentage was recorded on treatment days 1 and 2, whereas ACTH treatment had no effect on basophil percentage. In conclusion, three-day administration of ACTH to young boars during restraint caused effects similar to acute stress situations, as suggested by disappearance of the effects on immune function after the last drug dosage.

Rank in a food competition test and humoral immune functions in male Brandt's voles (Lasiopodomys brandtii)

Social status can influence an animal's immune and reproductive functions, eventually leading to alterations in immunocompetence and reproductive success. Here, we report that rank assessed in a food competition test, considered as an index of social status, has significant influences on humoral immune functions in male Brandt's voles (Lasiopodomys brandtii) living in a group. Our data reveal a negative correlation of the spleen mass and serum antibody levels with social status, as well as a positive correlation of serum cortisol levels with social status. Males winning in food competition had a smaller spleen, a lower level of serum antibodies, and a higher level of serum cortisol than did their conspecific counterparts. These data indicate interactions between social status and humoral immune functions and might illustrate a trade-off between infection risks and reproductive success in male Brandt's voles.

Development of bioprocess for the production of purified protein derivative with Brazilian strains of Mycobacterium tuberculosis for diagnosis use

Tuberculin, a purified protein derivative (PPD), when diluted in adequate concentration it is utilized for an early detection and to control tuberculosis. In Brazil, the PPD is imported and distributed by the Health System in all Brazilian regions. This, in addition to eventual delay in delivery caused by the legal import process, makes difficult the access of the product to poor communities from distant places as Brazil is a geographically a large country. Thus, indigenous production of PPD would be very beneficial for the society. This work was undertaken with a view to initiate studies towards the development of an indigenous technology for PPD production, using the strains of Mycobacterium tuberculosis isolated from patients during the course of disease from several regions of Brazil. The strain selection criteria for PPD production were the sequencing of three immunodominant proteins and the genetic differentiation by DNA fingerprinting and grouped by UPGMA program, the capacity of protein production in liquid medium, and finally the intradermal injection tests used on animal model. Compared to gold standard, the PPD showed similar indurations when tested individually, and better results were obtained when products were combined in pool. These strategies are discussed in detail in this research.

Rhinitis and asthma in athletes: an ARIA document in collaboration with GA2LEN

This consensus document is aimed at reviewing evidence that the rhinitis-asthma links have peculiar features in athletes. Beside a review of epidemological data on the high prevalence of rhinitis and asthma in athletes, the effects on intense physical exercise on the immune system and repiratory functions are discussed, with special reference to the role of allergens and pollutants. In extending the Allergic Rhinitis and its Impact on Asthma (ARIA) recommendations to athletes, the issue is addressed of adapting diagnosis and management to criteria set by the International Olympic Committee (IOC) and regulations adopted by the World Anti-Doping Agency (WADA).

Augmentation and proliferation of T lymphocytes and Th-1 cytokines by Withania somnifera in stressed mice

Stress has been associated with reports of both greater severity and prolongation of diseases in patients with the infectious origin as well as other immune-mediated diseases. Withania somnifera, an Indian medicinal plant used widely in the treatment of many clinical conditions in India, was investigated for its anti-stress properties using BALB/c mice subjected to chronic stress. The study aimed to investigate chronic stress-induced alterations on Th1 lymphocyte subset distribution and corresponding cytokine secretion patterns. Oral administration of chemically standardized and identified aqueous fraction of W. somnifera root (WS) at the graded doses of 25, 50, 100 and 200 mg/kg p.o. caused significant increase in the stress-induced depleted T-cell population and increased the expression of Th1 cytokines in chronically stressed mice.

The mechanism of acupuncture and clinical applications

This study presents the result of the studies explaining the effects of acupuncture on various systems and symptoms. It has been determined that endomorphin-1, beta endorphin, encephalin, and serotonin levels increase in plasma and brain tissue through acupuncture application. It has been observed that the increases of endomorphin-1, beta endorphin, encephalin, serotonin, and dopamine cause analgesia, sedation, and recovery in motor functions. They also have immunomodulator effects on the immune system and lipolithic effects on metabolism. Because of these effects, acupuncture is used in the treatment of pain syndrome illnesses such as migraine, fibromyalgia, osteoarthritis, and trigeminal neuralgia; of gastrointestinal disorders such as disturbance at gastrointestinal motility and gastritis; of psychological illnesses such as depression, anxiety, and panic attack; and in rehabilitation from hemiplegia and obesity.

Effect of radiofrequency ablation of the liver on cell-mediated immunity in rats

We investigated the effect of radiofrequency ablation (RFA) of the liver on cell-mediated immunity in rats. Sprague-Dawley rats were divided into five groups: control group that did not have any procedure, a sham-operation group that underwent laparotomy, a lobectomy group that had left lateral lobectomy of the liver, a one-lobe RFA group that had RFA on the left lateral lobe of the liver, and a two-lobe RFA group that had RFA on the left lateral and left median lobe of the liver. Delayed-type hypersensitivity (DTH) was induced by challenging the ears of previously sensitized rats with 2,4-dinitro-1-fluorobenzene. Cell-mediated immunity was evaluated by direct measurement of the ear thickness and quantitative analysis of leukocytic infiltration of the tissue. The increased ear thickness was 42.0%, 69.2%, 61.8%, 46.7%, and 39.8% from the baseline one day after each procedure, and the mean leukocytic infiltration into the ear tissue was 3136.7, 3895.0, 3913.3, 2803.3, and 2316.7/mm(2) seven days after each procedure in the control, sham-operation, lobectomy, one-lobe RFA, and two-lobe RFA groups, respectively. In conclusion, RFA of the liver tissue can partially abolish the augmentation of DTH and leukocytic infiltration those were seen in the hepatic lobectomy and sham-operation groups. The procedure had a negative effect on cell-mediated immunity in rats, and the intensity of RFA showed a reverse correlation with cell-mediated immunity.

Effects of dexamethasone on peripheral blood mononuclear cell phenotype in weanling piglets

The aim of this study was to evaluate the effect of dexamethasone treatment on the immune system of weanling piglets. Piglets were administered dexamethasone (DEX; 1mg/kg, IM) every 12h for 2 consecutive days (short-term experiment) or DEX (1mg/kg, IM) daily for 2 weeks (long-term experiment). The relative percentage of CD8(+) T cells in peripheral blood mononuclear cells (PBMCs) was significantly decreased (P<0.05) in both short- and long-term DEX-treated groups compared to their control groups. The percentage of IgM(+) cells in PBMCs of the long-term DEX-treated group was greatly increased (P<0.05) in comparison to the control group. The results of this study indicate that short-term DEX-treatment increases leucocyte function; however, long-term DEX-treatment depresses leucocyte function, especially that of CD8(+) T cells.

Effect of ACTH administration on biochemical and immune measures in boars

The effects of stress induced by adrenocorticotropic hormone (ACTH) on biochemical and immune changes in Swedish Landrace boars aged approximately 6-7 months were observed during ACTH administration and for 16 days after the cessation of treatment. Adrenocorticotropic hormone treated animals (n = 7) were given intravenously 10 microg/kg body mass of ACTH for 3 days. Control group of animals (n = 7) received intramuscularly 1 ml of sterile 0.9% saline. Total protein and globulin levels were significantly elevated during the induced stress period and for the next 16 days (P < 0.01 to P < 0.0001, respectively). Also, serum immunoglobulin IgG concentration was significantly elevated during and after ACTH injection (P < 0.001 to P < 0.0001). Adrenocorticotropic hormone treatment had no effect on serum albumin, IgA and IgM concentrations. Glucose concentration was significantly decreased on the second day of ACTH administration (P < 0.001) and on day 9 after treatment (P < 0.001). Calcium level was significantly decreased only for 24 h after the last ACTH dosage (P < 0.01). Also, serum phosphorus level was significantly decreased on the first (P < 0.05) and third (P < 0.001) days of ACTH challenge but remained unaffected after the cessation of ACTH treatment. It is concluded that the administration of ACTH to boars results in immune humoral and biochemical changes during stress and the post-stress period.

Trypanosomes, fleas and field voles: ecological dynamics of a host-vector--parasite interaction

To investigate the prevalence of a flea-borne protozoan (Trypanosoma (Herpetosoma) microti) in its field vole (Microtus agrestis) host, we monitored over a 2-year period a range of intrinsic and extrinsic parameters pertaining to host demographics, infection status and vector (flea) prevalence. Generalized Linear Mixed Modelling was used to analyse patterns of both flea and trypanosome occurrence. Overall, males of all sizes and ages were more likely to be infested with fleas than their female counterparts. Flea prevalence also showed direct density dependence during the winter, but patterns of density dependence varied amongst body mass (age) classes during the summer. Trypanosome prevalence did not vary between the sexes but was positively related to past flea prevalence with a lag of 3 months, with the highest levels occurring during the autumn season. A convex age-prevalence distribution was observed, suggesting that individuals develop a degree of immunity to trypanosome infection with age and exposure. An interaction between age and whether the individual was new or recaptured suggested that infected animals are less likely to become territory holders than their uninfected counterparts.

Animal models of tuberculosis

It was Robert Koch who recognized the spectrum of pathology of tuberculosis (TB) in different animal species. The examination of clinical specimens from infected humans and animals confirmed the variable patterns of pathological reactions in different species. Guinea pigs are innately susceptible while humans, mice and rabbits show different level of resistance depending upon their genotype. The studies of TB in laboratory animals such as mice, rabbits and guinea pigs have significantly increased our understanding of the aetiology, virulence and pathogenesis of the disease. The introduction of less than five virulent organisms into guinea pigs by the respiratory route can produce lung lesions, bacteraemia and fatal diseases, which helped the extrapolation of results of such experiments to humans. The similarities in the course of clinical infection between guinea pigs and humans allow us to model different forms of TB and to evaluate the protective efficacy of candidate vaccines in such systems. The only limitation of this model, however, is a dearth of immunological reagents that are required for the qualitative and quantitative evaluation of the immune responses, with special reference to cytokines and cell phenotypes. Another limitation is the higher cost of guinea pigs compared with mice. The rabbit is relatively resistant to Mycobacterium tuberculosis, however following infection with virulent Mycobacterium bovis, the rabbit produces pulmonary cavities like humans. The rabbit model, however, is also limited by the lack of the immunological reagents. Mice are the animal of choice for studying the immunology of mycobacterial infections and have contributed much to our current understanding of the roles of various immunological mechanisms of resistance. The resistance of mice to the development of classic TB disease, however, represents a significant disadvantage of the mouse model. Although non-human primates are closely related to humans, owing to high cost and handing difficulties they have not been exploited to a large extent. As all existing animal models fail to mimic the human disease perfectly, efforts should be focused on the development of the non-human primate(s) as the alternative animal model for TB.

The mediation effect of posttraumatic stress disorder symptoms on the relationship of intimate partner violence and IFN-gamma levels

BACKGROUND

Women who experience intimate partner violence (IPV) report greater stress and negative health consequences than nonabused women. Although an association between psychological stress and altered immune function has been shown, IPV studies have not investigated this relationship.

OBJECTIVE

This study explored the association of IPV with mental health symptoms and an immune marker to determine if posttraumatic stress disorder (PTSD) symptoms mediate the effect of IPV on pro-inflammatory (IFN-gamma) cytokine levels.

METHODS

A cross-sectional, comparative design was used to compare 62 women with IPV and 39 nonabused women.

RESULTS

Mean IFN-gamma values were higher in abused women and in women with current PTSD symptoms. There were no significant relationships with potential confounding variables that could provide an alternative explanation for the increase in production of proinflammatory cytokines.

CONCLUSIONS

PTSD symptoms mediate the association between IPV and IFN-gamma levels and may partially explain the association of mental health symptoms with physical health sequelae in IPV.

Modifications of serum and cellular parameters in trotters after a race. Macrophage migration inhibitory activity reduction and serum beta-glucan elevation

Trotters are exposed to a chronic prolonged stress, such as daily training and frequent races during their active lifespans. There is evidence that trotters undergo very often lethal lung infections after a race, and therefore, is likely that modifications of certain physiologic cellular parameters could account for the increased susceptibility to microbial diseases. Here, we demonstrate that in 7 trotters after a race either serum values (e.g., glycaemia, triglycerides, transaminases, gamma-glutamyltransferase, cholinesterase, amylase, alkaline phosphatase, total proteins, serum albumin, sodium, blood urea nitrogen, lactic dehydrogenase, creatine phosphokinase, and creatinine) or hematological parameters (red blood cell count, hemoglobin, lymphocyte and monocyte count) were increased. At the same time, in the same animals after a race, macrophage migration inhibitory factor activity was depressed, thus indicating an impaired T-lymphocyte response. Finally, increased levels of circulating beta-glucans in some horses, after a race, may suggest a reduced clearance of fungal cell wall components. Taken together, these findings indicate a condition of multiple organ dysfunction, such as the liver, the kidney, the pancreas, and skeletal muscles, as well as a reduced cell-mediated immune response in trotters, after a race.

Trypanosoma cruzi: Effects of repetitive stress during the development of experimental infection

Activation of the hypothalamus-pituitary-adrenal axis plays a major role in the suppression of the immune system. We have investigated the effects of repetitive stress on Wistar rats infected with the Y strain of Trypanosoma cruzi and a control group that underwent stressor stimuli by exposure to ether vapor for one minute twice a day. Repetitive stress resulted in an elevated number of circulating parasites accompanies by deep tissue disorganization, and cardiac histopathological alterations. The infected and stressed group displayed a decrease in body weight, and an increased parasite burden in heart tissue, and adrenal glands. Histological analysis of the heart also showed a moderate to severe diffused mononuclear inflammatory process. These results suggest that repetitive stress could be considered an important factor during development of experimental Chagas' disease, enhancing pathogenesis through disturbance of the host's immune system.

Acute stress reduces intraparenchymal lung natural killer cells via beta-adrenergic stimulation

There are lines of evidence that natural killer (NK) cells are sensitive to physical and psychological stress. Alterations in the immune system including NK cells are known to differ among tissues and organs. The effect of stress on the lung immune system, however, has not been well documented in spite of the fact that the lungs always confront viral or bacterial attacks as well as tumour cell metastasis. In this study, we intended to investigate the effect of restraint stress on lung lymphocytes including NK cells. C57BL/6 mice were exposed to 2 h restraint stress. The concentration of plasma epinephrine significantly rose immediately after the release from restraint as compared to home-cage control mice. Flow cytometric analysis revealed that the numbers of most lymphocyte subsets including NK cells were decreased in the lungs and blood but not in the spleen, immediately after restraint stress. Immunohistochemical examination revealed that the number of NK cells was decreased in the intraparenchymal region of the lungs, while the number of alveolar macrophages did not change. The decrease in the number of NK cells in the lungs and blood was reversed by the administration of propranolol, a nonselective beta adrenergic antagonist. Taken together, our findings suggest that acute stress reduces the number of intraparenchymal lung NK cells via activation of beta adrenergic receptors.

Myelopoietic Response in Mice Exposed to Acute Cold/Restraint Stress: Modulation by Chlorella vulgaris Prophylactic Treatment

In this study, hematopoietic cells from mice pretreated with CVE and exposed to acute cold/restraint stress were stimulated in the presence of growth factors to form colonies, thus providing accurate information about the modulation of the green algae of the stress-induced changes in the hematopoietic response. Our results demonstrated that exposure to acute stress affected hematopoiesis. Mice exposed for a 2.5-hour time period of cold and restraint presented diminished clonal capacity for CFU-GM content per femur, which was decreased by as much as 50% compared with that in control mice, in spite of the significant increase in serum colony-stimulating activity (CSA). Treatment with 50 mg/kg CVE for 5 days, previously to the stress regimen, attenuates the effects of the stress, since comparable levels of myeloid progenitors were found in the bone marrow of both CVE/stress and control mice. Moreover, the sera from stressed mice pretreated with CVE further increased the CFU-GM formation. On the contrary, the spleen seemed to be less sensitive to acute stress in our experimental conditions. These findings are in line with our previous reports showing that the stress-induced reduction in bone marrow CFU-GM of rats exposed to electric shocks is mediated by activation of the HPA axis and by secretion of opioid agonists. No changes were observed in bone marrow, spleen and thymus total cell counts, and in relative organ weights. However, a 50% reduction in the body weight loss produced by the stress was observed in mice given the extract.

Dual mode of catecholamine action on splenic macrophage phagocytosis in wall lizard, Hemidactylus flaviviridis

In the present study, in vitro concentration-related effect of catecholamines, dopamine (DA), norepinephrine (NE), and epinephrine (E) was observed on phagocytic activity of splenic macrophages to understand the impact of sympatho-adrenal-medullary (SAM) activation on innate immunity in wall lizard Hemidactylus flaviviridis under stress condition. Restraint stress for 1 h resulted in marked suppression of macrophage phagocytosis, suggesting that supra-physiological level of catecholamines in response to SAM activation under stress suppressed phagocytosis. This interpretation was reinforced since all the catecholamines considerably reduced phagocytosis at high concentrations ranging from 10(-7) to 10(-5)M. On the contrary, DA, NE, and E at low concentrations considerably stimulated phagocytosis, which increased with the decrease of concentrations ranging from 10(-11) to 10(-15)M. Further, effect of NE and E was blocked by beta-adrenergic blocker suggesting the beta-adrenoceptor-dependent regulating mechanism of NE and E. DA acts through both beta-adrenoceptor-dependent and D1/D2 class receptor-dependent mechanism, since beta-adrenergic blocker could partially block the DA effect. beta-Adrenoceptor-linked adenylate cyclase-mediated cAMP action in modulation of phagocytic activity was evident as 3-isobutyl-1-methyl-xanthine suppressed phagocytosis. Further, to delineate the mode of dual effect of catecholamines through beta-adrenergic receptors, in vitro concentration-related effect of cAMP was investigated on macrophage phagocytosis. cAMP depending on concentration had opposite effect on phagocytosis, and its stimulatory effect at low concentrations was reversed by actinomycin D and cycloheximide, whereas these transcription and translation inhibitors, respectively, failed to alter the inhibitory effect of cAMP at high concentrations. This suggests the concentration-related two different pathways of catecholamine action, classical non-genomic at high concentration while genomic pathway at low concentration.