Glucocorticoids and the Th1/Th2 balance

Increased number of activated T cells in lymphocyte subsets of maltreated children: data from a pilot study

OBJECTIVE

Maltreatment in childhood has been related to enduring changes in the immune system of adults, such as increased cell-mediated immune response.

PURPOSE

Due to the lack of data in children, this study examined lymphocyte subset numbers and distribution during youth.

METHODS

In 27 cases of 42 healthy but maltreated children, fully participating at follow-up 1-3years after the intervention of child protection team, and 19 cases of previously matched controls, analysis of blood samples by fluorescent activated cell sorter was consented.

RESULTS

With regard to age references, total lymphocyte counts were aberrant in maltreated children but not in controls. When compared to controls, the percentages and absolute numbers of activated (HLA-DR+) CD4+helper and CD8+cytotoxic T cells were significantly higher in maltreated children.

CONCLUSIONS

According to the typical distribution of HLA-DR+cells we assumed an increased stimulated cell-mediated immune function in maltreated children.

Involvement of stress in the pathogenesis of autoimmune thyroid disease: a prospective study

BACKGROUND

An association between stress and autoimmune thyroid disease (AITD) (especially Graves' hyperthyroidism) has been reported, but all studies so far on this topic have been retrospective.

OBJECTIVE

To evaluate prospectively the relationship between stress and (i) de novo occurrence of thyroid antibodies and (ii) development of overt autoimmune hyper-/hypothyroidism.

STUDY DESIGN

Two nested case-control studies in a prospective cohort of 790 euthyroid women who were 1st or 2nd degree relatives of AITD patients. Follow-up was five year, with annual assessments including questionnaires on stressful life events, daily hassles, and mood. In study A, cases were subjects who developed TPO-Ab but remained euthyroid during follow-up (called event). In study B, cases were subjects who developed overt hypothyroidism (TSH>5.7 mU/l and FT4<9.3 pmol/l) or overt hyperthyroidism (TSH<0.4 mU/l and FT4>20.1 pmol/l) during follow-up (called event). For each case, two controls were selected, matched for age and duration of follow-up; controls in study A remained TPO-Ab negative, and in study B remained without overt hyper-/hypothyroidism.

OUTCOMES

Contrast in questionnaire responses between cases and controls at baseline, at one year prior to the event and at time of event.

RESULTS

Exposure to stress was not different between subjects who developed or did not develop TPO-Ab (study A). No differences were observed in stress questionnaires between hyper-/hypothyroid cases and controls at any time point, but hypothyroid cases had less negative feelings than controls at the time of diagnosis (study B).

CONCLUSION

The data suggest that stress is not involved in the pathogenesis of AITD.

Exercise and the aging immune system

Aging is associated with a decline in the normal functioning of the immune system that is described by the canopy term "immunosenescence". This contributes to poorer vaccine responses and the increased incidence of infection and malignancy seen in the elderly. Regular exercise has been associated with enhanced vaccination responses, lower numbers of exhausted/senescent T-cells, increased T-cell proliferative capacity, lower circulatory levels of inflammatory cytokines ("inflamm-aging"), increased neutrophil phagocytic activity, lowered inflammatory response to bacterial challenge, greater NK-cell cytotoxic activity and longer leukocyte telomere lengths in aging humans, all of which indicate that habitual exercise is capable of regulating the immune system and delaying the onset of immunosenescence. This contention is supported by the majority of animal studies that report improved immune responses and outcomes to viral infections and malignancies due to exercise training. However, whether or not exercise can reverse, as well as prevent, immunosenescence is a contentious issue, particularly because most longitudinal exercise training studies do not report the same positive effects of exercise on immunity that have been widely reported in studies with a cross-sectional design. In this review, we summarize some of the known effects of exercise on immunosenescence, discuss avenues for future research, and provide potential mechanisms by which exercise may help rejuvinate the aging immune system.

Role of fluconazole in a case of rapid onset ritonavir and inhaled fluticasone-associated secondary adrenal insufficiency

A 52-year-old man with well-controlled HIV infection taking ritonavir and increasing doses of inhaled fluticasone for chronic bronchitis developed thrush. Within days of discontinuing fluticasone and initiating fluconazole, he presented with fatigue, malaise, lower-extremity oedema and orthostasis. Testing confirmed exogenous Cushing's syndrome and secondary adrenal insufficiency. Although ritonavir–fluticasone interactions have been previously reported as a cause for adrenal insufficiency, we propose that fluconazole increased the rapidity of onset and severity of symptoms through synergistic inhibition of the adrenal axis.

The role of pro- and anti-inflammatory cytokines in the pathogenesis of spontaneous canine CNS diseases

Dogs are comparatively frequently affected by various spontaneously occurring inflammatory and degenerative central nervous system (CNS) conditions, and immunopathological processes are a hallmark of the associated neuropathology. Due to the low regenerative capacity of the CNS a sophisticated understanding of the underlying molecular basis for disease initiation, progression and remission in canine CNS diseases represents a prerequisite for the development of novel therapeutical approaches. In addition, as many spontaneous canine CNS diseases share striking similarities with their human counterpart, knowledge about the immune pathogenesis may in part be translated for a better understanding of certain human diseases. In addition to cytokine-driven differentiation of peripheral leukocytes including different subsets of T cells recent research suggests a pivotal role of these mediators also in phenotype polarization of resident glial cells. Cytokines thus represent the key mediators of the local and systemic immune response in CNS diseases and their orchestration significantly decides on either lesion progression or remission. The aim of the present review is to summarize the growing number of data focusing on the molecular basis of the immune response during spontaneous canine CNS diseases and to detail the effect of cytokines on the immune pathogenesis of selected idiopathic, infectious, and traumatic canine CNS diseases. Steroid-responsive meningitis arteritis (SRMA) represents a unique idiopathic disease of leptomeningeal blood vessels characterized by excessive IgA secretion into the cerebrospinal fluid. Recent reports have given sophisticated insights into the cytokine-driven, immune-mediated pathogenesis of SRMA that is characterized by a biased T helper 2 cell response. Canine distemper associated leukoencephalitis represents an important spontaneously occurring disease that allows investigations on the basic pathogenesis of immune-mediated myelin loss. It is characterized by an early virus-induced up-regulation of pro-inflammatory cytokines with chronic bystander immune-mediated demyelinating processes. Lastly, canine spinal cord injury (SCI) shares many similarities with the human counterpart and most commonly results from intervertebral disk disease. The knowledge of its pathogenesis is largely restricted to experimental studies in rodents, and the impact of immune processes that accompany secondary injury is discussed controversially. Recent investigations on canine SCI highlight the pivotal role of pro-inflammatory cytokine expression that is paralleled by a dominating reaction of microglia/macrophages potentially indicating a polarization of these immune cells into a neurotoxic and harmful phenotype. This report will review the role of cytokines in the immune processes of the mentioned representative canine CNS diseases and highlight the importance of cytokine/cytokine interaction as a useful therapeutic target in canine CNS diseases.

The influence of reproductive physiology and nutrient supply on the periparturient relaxation of immunity to the gastrointestinal nematode Trichostrongylus colubriformis in Merino ewes

A pen experiment was conducted to investigate the interaction of early-weaning and nutrient supply on the periparturient relaxation of immunity to the gastrointestinal nematode (GIN) Trichostrongylus colubriformis in Merino ewes. Mixed-age pregnant and non-pregnant (dry) ewes were infected with 8,000 T. colubriformis L(3)/week, and fed either a high or low quality diet. Following parturition, lambs were either removed from their mothers at 2 days of age or allowed to continue suckling. Systemic immunity began to wane during late pregnancy with circulating eosinophils and plasma total antibody (Ab) levels declining from day -37 (relative to the midpoint of lambing) and day -24, respectively. Pregnant ewes fed the low quality diet exhibited an increasing faecal worm egg count (WEC) from day -24 and had higher intestinal worm burdens on day 13, whereas ewes fed the high quality diet had a delayed transient rise in WEC of lower magnitude. Dry and early-weaned ewes remained highly resistant to T. colubriformis at all times. In the post-lambing/lactation period, ewes fed the high quality diet had higher levels of local total Ab and numbers of goblet cells (GC) in the small intestine on days 13 and 41. Lactating/suckled ewes had a lower anti-parasite local immune response as indicated by reduced titres of total Ab, IgG(1), IgM and IgA and lower numbers of mucosal mast cells (MMC), globule leukocytes (GL) and GC in small intestinal tissue compared to their dry and early-weaned counterparts. Early-weaning resulted in rapid recovery of blood eosinophils and total Ab. On day 13 post-lambing, titres of total Ab, IgG(1), IgM, IgA and IgE, and numbers of MMC and GL were greater than those measured in dry and suckled ewes. When fed the high quality diet, ewes had a higher dry matter (DM) intake, maternal weight, fat score, greater fat depth and eye muscle depth, birthed heavier lambs that had higher growth rates, and produced more milk. The physiological status of pregnancy resulted in a higher DM intake but lower measures of fat depth and eye muscle depth, and suckling led to an increase in DM intake but a reduction in body weight and fat score through mobilisation of fat and muscle reserves. Despite the marked effect of diet quality on production traits, some inconsistencies were observed between body composition and apparent parasite resistance, measured by WEC and worm counts, suggesting that the nutritional influence was not necessarily always mediated through changes in body composition. Although reproductive status affected blood leptin levels, diet had no effect within suckled ewes and therefore it was concluded that leptin has no causative role in maintaining the periparturient relaxation of immunity to T. colubriformis.

The roles of the immune system in women's reproduction: evolutionary constraints and life history trade-offs

Life history theory posits that, as long as survival is assured, finite resources are available for reproduction, maintenance, and growth/storage. To maximize lifetime reproductive success, resources are subject to trade-offs both within individuals and between current and future investment. For women, reproducing is costly and time-consuming; the bulk of available resources must be allocated to reproduction at the expense of more flexible systems like immune function. When reproducing women contract infectious diseases, the resources required for immune activation can fundamentally shift the patterns of resource allocation. Adding to the complexity of the reproductive-immune trade-offs in women are the pleiotropic effects of many immune factors, which were modified to serve key roles in mammalian reproduction. In this review, we explore the complex intersections between immune function and female reproduction to situate proximate immunological processes within a life history framework. After a brief overview of the immune system, we discuss some important physiological roles of immune factors in women's reproduction and the conflicts that may arise when these factors must play dual roles. We then discuss the influence of reproductive-immune trade-offs on the patterning of lifetime reproductive success: (1) the effect of immune activation/infectious disease on the timing of life history events; (2) the role of the immune system, immune activation, and infectious disease on resource allocation within individual reproductive events, particularly pregnancy; and (3) the role of the immune system in shaping the offspring's patterns of future life history trade-offs. We close with a discussion of future directions in reproductive immunology for anthropologists.

Xiaoyin recipe ( ) for psoriasis induces a Th1/Th2 balance drift toward Th2 in peripheral blood mononuclear cells of experimental autoimmune thyroiditis rats

OBJECTIVE

To explore the regulatory mechanism of Xiaoyin Recipe () on the T helper 1/T helper 2 (Th1/Th2) immune balance.

METHODS

Thirty-six experimental animals were divided into three groups, 12 rats in each group: blank control group (B group), negative control group (N group), and Xiaoyin Recipe treatment group (T group). The latter two groups received immunization of experimental autoimmune thyroiditis (EAT), and T group were treated with Xiaoyin Recipe for a month. Then, the expression of Th1-Th2-related genes in peripheral blood mononuclear cells (PBMCs) were screened with Oligo GEArray Rat Th1-Th2-Th3 Microarray. The expressions of tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), T-box expressed in T-cells (T-bet), and GATA-binding protein-3 (GATA-3) were detected by real-time polymerase chain reaction (RT-PCR).

RESULTS

Gene array screening showed that compared to N group, in T group after Xiaoyin Recipe treatment, 3 genes were upregulated in EAT rats, including interleukin-27 receptor alpha (IL-27rα), glomulin (Glmn), and GATA-3, while 38 genes were downregulated, such as CD28, IL-18, signal transducer, and activator of transcription 1 (STAT1), T-bet, TNF receptor superfamily member 4 (TNFRSF4), TNF ligand superfamily member 5 (TNFSF5), and TNF receptor superfamily member 5 (TNFRSF5). While RT-PCR showed that there was an increased level of TNF-α mRNA (P<0.01), an elevated ratio of T-bet/GATA-3, and a decreased level of IL-10 mRNA in PBMC of N and T group compared to B group (P <0.01); and after treatment with Xiaoyin Recipe, IL-10 mRNA level increased (P <0.01), while TNF-α mRNA level and T-bet/GATA-3 ratio decreased in T group compared to N group (P <0.01).

CONCLUSION

Xiaoyin Recipe for psoriasis could induce a Th1/Th2 balance drift toward Th2 in PBMC of EAT rats and thus improve the conditions.

Pregnancy and rheumatoid arthritis: insights into the immunology of fetal tolerance and control of autoimmunity

It has long been recognized that symptoms and signs of rheumatoid arthritis (RA) frequently improve spontaneously during pregnancy, only to flare postpartum. Although the mechanisms behind this phenomenon remain poorly understood, there is growing interest in the immunologic changes that occur during healthy pregnancy as a possible explanation. Because the maternal immune system must adapt during pregnancy to accept the semi-allogeneic fetus, it has been hypothesized that these natural changes induced by pregnancy on maternal immune regulatory cells may have the additional benefit of controlling the immunopathology driving disease activity in RA. Here, we review our current understanding on the effects of pregnancy on RA and highlight some of the recent literature related to advancing our understanding on the immunology of pregnancy as well as the immunologic changes in RA during pregnancy.

Neuroimmunological response of beluga whales (Delphinapterus leucas) to translocation and a novel social environment

This study assessed changes in phagocyte function and activation of the sympatho-adrenal medullary and hypothalamo-pituitary adrenal axes of beluga whales (Delphinapterus leucas) in response to translocation and introduction to a novel social environment. Transported belugas exhibited increases in epinephrine (E), norepinephrine (NE), and cortisol levels in response to the translocation process. In response to the introduction of the transported belugas, resident belugas exhibited an increase in E and NE but not cortisol. Moreover, the increase in E and NE shown by the transported belugas was significantly greater than the increase exhibited by the resident belugas. Resident belugas exhibited a concomitant decrease in neutrophil and monocyte phagocytosis associated with the introduction of the transported belugas. In contrast, transported belugas exhibited an attendant increase in phagocytosis and respiratory burst activity immediately following transport. Differences in phagocyte response may derive from differences in hormonal milieu, stressor modality and/or intensity, or phagocyte priming. Investigating the complex interactions between types of stressors, neuroendocrine response, and immunocompetence will lead to a better understanding of the impacts of environmental challenges, including anthropogenic perturbations, on the health of cetacean populations.

MIC-1 (a multifunctional modulator of dendritic cell phenotype and function) is produced by decidual stromal cells and trophoblasts

BACKGROUND

Macrophage inhibitory cytokine-1 (MIC-1) is a multifunctional cytokine produced in high amounts by placental tissue. Inhibiting trophoblast invasion and suppressing inflammation through inhibition of macrophage activation, MIC-1 is thought to provide pleiotropic functions in the establishment and maintenance of pregnancy. So far, little is known about the decidual cell subsets producing MIC-1 and the effect of this cytokine on dendritic cells (DCs), which are known to play a distinct role in the development of pro-fetal tolerance in pregnancy.

METHODS

To identify the decidual cell types expressing and secreting MIC-1, immunohistochemical staining, PCR experiments, western blot analysis and ELISAs were performed. Immature DCs (iDCs) were generated from peripheral blood-derived monocytes and differentiated in the presence of MIC-1 or dexamethasone (Dex) for control. Migratory and proliferative activity of DCs after MIC-1 exposure was investigated by migration and proliferation assay. Cytokine secretion after MIC-1 exposure was tested in isolated uNK cells, isolated CD14+ monocytes, monocyte-derived iDCs and mature DCs. Subsequently, the phenotype of DCs was studied using FACS analysis. To test the T-cell stimulatory capacity of pre-incubated DCs, mixed lymphocyte reaction was applied. Finally, the expression of the tryptophan-catabolizing enzyme indoleamine 2,3-dioxygenase (IDO) after the exposure of MIC-1 to maturing DCs was analysed by western blot.

RESULTS

Immunohistochemical staining, PCR and western blot experiments demonstrated that MIC-1 is mainly expressed by trophoblast cells and decidual stromal cells. Analysis of the MIC-1 secretion of decidual cell types by ELISA again characterized trophoblast and stromal cells as main producers. The migratory activity of iDCs was significantly induced by MIC-1. No changes in proliferative activity of DCs were observed after MIC-1 pre-incubation. The secretion of pro- or anti-inflammatory cytokines was not affected significantly by MIC-1. Studying the phenotype of DCs after MIC-1 exposure by FACS analysis, we observed that MIC-1 suppresses the expression of typical maturation molecules such as CD25 and CD83 as well as of CD86 during cytokine-induced DC maturation similar to Dex. In addition, T-cell stimulatory capacity of DCs was significantly reduced after MIC-1 exposure. MIC-1 was also able to increase slightly the expression of IDO (a key immunomodulatory enzyme promoting periphereal tolerance) in maturing DCs.

CONCLUSIONS

We have identified MIC-1 as a novel factor (secreted by decidual cells in early pregnancy) that could promote the increase of a tolerogenic subtype of DC in decidua.

Effect of gender and menstrual cycle on immune system response to acute mental stress: apoptosis as a mediator

BACKGROUND/AIMS

We aimed to explore the immunological outcomes of short-term mental stress in apoptosis in peripheral lymphocytes and variations by gender and hormonal status of the individuals together with possible mediators of this interaction.

METHODS

Acute mental stress (computerized Stroop color-word interference and cold pressor tests) was applied to men (n = 17) and women (n = 16, in both follicular and luteal phases). Heart rate and blood pressure were monitored throughout the test and after the test until baseline values were recorded. Blood samples were drawn for measuring cortisol and nitric oxide (NO) levels and flow-cytometric cell counting before and after the test.

RESULTS

Activation of the stress system was ascertained by increased heart rate, blood pressure and serum cortisol levels after the test. Relative to baseline values, acute mental stress altered the distribution of T and natural killer cells. There was a significant decrease in T helper/T cytotoxic-suppressor cell ratio and an increase in apoptotic T helper cell percentage irrespective of gender or menstrual cycle phase. An increased number of natural killer cells was detected in women, whereas it was decreased in men. After stress induction, serum NO levels remained the same in women and increased in men. Although a correlation was not found between immune system changes and NO levels, glucocorticoids seem to have a role in the observed differences.

CONCLUSION

Acute mental stress triggers apoptotic T helper cell loss which was associated with stress system activation, and sex steroids affect the pattern of stress-related immune cell distribution.

Psychoneuroimmunology of psychological stress and atopic dermatitis: pathophysiologic and therapeutic updates

Atopic dermatitis is a chronic inflammatory skin disease characterized by impaired epidermal barrier function, inflammatory infiltration, extensive pruritus and a clinical course defined by symptomatic flares and remissions. The mechanisms of disease exacerbation are still poorly understood. Clinical occurrence of atopic dermatitis is often associated with psychological stress. In response to stress, upregulation of neuropeptide mediators in the brain, endocrine organs, and peripheral nervous system directly affect immune and resident cells in the skin. Lesional and non-lesional skin of patients with atopic dermatitis demonstrates increased mast cells and mast cell-nerve fiber contacts. In the setting of stress, sensory nerves release neuromediators that regulate inflammatory and immune responses, as well as barrier function. Progress towards elucidating these neuroimmune connections will refine our understanding of how emotional stress influences atopic dermatitis. Moreover, psychopharmacologic agents that modulate neuronal receptors or the amplification circuits of inflammation are attractive options for the treatment of not only atopic dermatitis, but also other stress-mediated inflammatory skin diseases.

Immunology of uterine transplantation: a review

The idea of using organ transplantation to solve quality-of-life issues was first introduced a century ago, with cornea transplants and thrusted before the world again in 1998, following a controversial hand transplant. Uterus transplantation (UTn) has been proposed as another quality-of-life transplant for the cure of permanent uterine factor infertility. In order to proceed in humans, a greater appreciation of the immunological mechanisms that underlie UTn is desirable. Allogeneic UTn (animal model) was first described by 2 studies in 1969. The first and only human UTn, performed in 2000, was an early attempt with limited use of animal model experiments prior to moving onto the human setting. Since then, work using rat, mouse, ovine, goat, and nonhuman primate models has demonstrated that the uterus is a very different but manageable organ immunologically compared to other transplanted organs. Therefore, specifically exploring immunological issues relating to UTn is a valuable and necessary part of the inevitable scientific process leading to successful human UTn.

Prediction of atopic dermatitis in 2-yr-old children by cord blood IgE, genetic polymorphisms in cytokine genes, and maternal mentality during pregnancy

Atopic dermatitis (AD) is the most common skin disease in childhood and the first step of atopic march. This study aimed to investigate whether AD in children could be better predicted by biologic markers (cord blood IgE [cbIgE], LT-αNcoI alleles, and FcεRI-β E237G genotypes) and maternal mentality during pregnancy, taking into account gender, socio-demographic factors, and parental atopy. From 2001 to 2005, 1264 mother-infant pairs were recruited to participate in a birth cohort study. Prenatal questionnaire was used to collect family history, maternal gestational conditions and mentality, and environmental exposures. Cord blood was collected and assayed for genotypes and IgE levels. Phone interviews at 6 months and 2 yrs of age were conducted to inquire children's health status, including AD occurrence. In addition to the known risk factors such as gender, maternal education, and parental atopy, biomarkers and maternal mentality during pregnancy were screened by logistic regression as candidate predictors of AD. Area-under-curve (AUC) statistic from receiver-operating characteristic (ROC) curve analysis was used to compare two predicting models with and without biomarkers and maternal mentality. A total of 730 pairs completed the prenatal questionnaire and phone interview and were included in final analysis. The prevalence of ever having physician-diagnosed AD by 2-yr-olds was 5.9%. Elevated cbIgE levels (≥0.5 kU/l), LT-αNcoI alleles, FcεRI-β E237G genotype, and maternal psychologic stress during pregnancy were significantly associated with AD. Comparison with AUCs of the classic model (including gender, maternal education, and parental atopy), the model adding cbIgE levels, genotypes in cytokine genes, and maternal stress (model 2) showed higher ability to discriminate between children with and without AD (AUC statistics: 0.63 [95% CI = 0.60-0.67] vs. 0.73 [95% CI = 0.70-0.76], respectively; model comparison, p = 0.027). We conclude that elevated cbIgE, LT-α and FcεRI-β genotypes, and maternal stress during pregnancy were associated with ever having physician-diagnosed AD in 2-yr-old children and increased the predictive ability for AD after taking into account gender, maternal education, and parental atopic history.

Low-dose gamma-rays and simulated solar particle event protons modify splenocyte gene and cytokine expression patterns

The goal was to investigate the T helper (Th) response in splenocytes of mice exposed to low-dose/low-dose-rate (LDR) γ-rays, simulated solar particle event protons (sSPE), or combination of both. C57BL/6 mice were exposed to LDR γ-radiation ((57)Co) to a total dose of 0.05 Gray (Gy) at 0.024 cGy/h, either with or without subsequent exposure to 2 Gy sSPE protons. Expression of genes related to Th cells was evaluated immediately after exposure (day 0). On day 21, intra- and extracellular cytokine production was assessed after activation with anti-CD3 monoclonal antibodies (mAb) or phorbol 12-myristate 13-acetate/ionophore (PMA/I). Five genes were significantly modulated on day 0 in one or more of the irradiated groups compared to controls (p < 0.05): Ccl11, Ccr5, Cd80, Inha, and Il9. On day 21, numbers of cells positive for interferon-γ were high in the LDR + sSPE group versus 0 Gy and LDR γ-rays (p < 0.05), but there was no difference in IL-2 and TNF-α. Levels of secreted cytokines after anti-CD3 mAb activation were high for 5 (MIP-1α, GM-CSF, IFN-γ, TNF-α, IL-13) and low for 2 (IL-7, IL-9) in all irradiated groups. Priming with LDR photons had a significant effect on IFN-γ and IL-17 compared to sSPE protons alone; IL-2 was low only in the LDR + sSPE group. The cytokine patterns after anti-PMA/I activation were different compared to anti-CD3 mAb and with fewer differences among groups. The data show that total-body exposure to space-relevant radiation has profound effects on Th cell status and that priming with LDR γ-rays can in some cases modulate the response to sSPE.

Medroxyprogesterone acetate alters Mycobacterium bovis BCG-induced cytokine production in peripheral blood mononuclear cells of contraceptive users

Most individuals latently infected with Mycobacterium tuberculosis (M.tb) contain the infection by a balance of effector and regulatory immune responses. This balance can be influenced by steroid hormones such as glucocorticoids. The widely used contraceptive medroxyprogesterone acetate (MPA) possesses glucocorticoid activity. We investigated the effect of this hormone on immune responses to BCG in household contacts of active TB patients. Multiplex bead array analysis revealed that MPA demonstrated both glucocorticoid and progestogenic properties at saturating and pharmacological concentrations in peripheral blood mononuclear cells (PBMCs) and suppressed antigen specific cytokine production. Furthermore we showed that PBMCs from women using MPA produced significantly lower levels of IL-1α, IL-12p40, IL-10, IL-13 and G-CSF in response to BCG which corresponded with lower numbers of circulating monocytes observed in these women. Our research study is the first to show that MPA impacts on infections outside the genital tract due to a systemic effect on immune function. Therefore MPA use could alter susceptibility to TB, TB disease severity as well as change the efficacy of new BCG-based vaccines, especially prime-boost vaccine strategies which may be administered to adult or adolescent women in the future.

Exercise-induced increases in inflammatory cytokines in muscle and blood of horses

REASONS FOR PERFORMING STUDY

Studies have demonstrated increases in mRNA expression for inflammatory cytokines following exercise in horses and have suggested those markers of inflammation may play a role in delayed onset muscle soreness. However, measurement of mRNA expression in white blood cells is an indirect method. No studies to date have documented the cytokine response to exercise directly in muscle in horses.

HYPOTHESIS

This study tested the hypothesis that exercise increases cytokine markers of inflammation in blood and muscle.

METHODS

Blood and muscle biopsies were obtained from 4 healthy, unfit Standardbred mares (∼ 500 kg). The randomised crossover experiment was performed with the investigators performing the analysis blind to the treatment. Each horse underwent either incremental exercise test (GXT) or standing parallel control with the trials performed one month apart. During the GXT horses ran on a treadmill (1 m/s increases each min until fatigue, 6% grade). Blood and muscle biopsies were obtained 30 min before exercise, immediately after exercise and at 0.5, 1, 2, 6 and 24 h post GXT or at matched time points during the parallel control trials. Samples were analysed using real time-PCR for measurement of mRNA expression of interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and interleukin-1 (IL-1). Data were analysed using t tests with the null hypothesis rejected when P < 0.10.

RESULTS

There were no changes (P > 0.10) in IL-1, IL-6, IFN-gamma or TNF-alpha during control. Exercise induced significant increases in IFN-gamma, IL1 and TNF-alpha in blood and significant increases in IFN-gamma, IL-6 and TNF-alpha in muscle. There were no significant changes in mRNA expression of IL-1 in muscle or IL-6 in blood following the GXT. These cytokine markers of inflammation all returned to preGXT levels by 24 h post GXT.

CONCLUSION

High intensity exercise results in a transient increase in the expression of inflammatory cytokines in muscle and blood.

A patient with erythema nodosus leprosum and Chagas cardiopathy: challenges in patient management and review of the literature

We report a patient with severe multi-bacillary leprosy complicated by recurrent episodes of erythema nodosum necrotisans that required thalidomide and/or corticosteroids during follow-up. Although the patient was from an area to which Chagas disease is endemic, this diagnosis was initially missed and was only investigated when heart failure developed in the patient. The difficulties of managing erythema nodosum necrotisans and heart failure concomitantly and those involved in excluding the diagnosis of acute myocarditis caused by reactivation of Chagas disease secondary to the immunosuppressive regimen are discussed. Other potential causes for the heart failure and possible interactions between the two diseases and their treatments are discussed. We also reviewed the literature for the association between leprosy and Chagas disease, both of which are highly endemic in Brazil. This case emphasizes the importance of searching for subclinical co-infections in leprosy patients because reactions frequently develop during specific treatment in these patients, and these reactions require prolonged therapy with immunosuppressive drugs.

Lack of the T cell-specific alternative p38 activation pathway reduces autoimmunity and inflammation

Stimulation via the T-cell receptor (TCR) activates p38α and p38β by phosphorylation of p38 Tyr-323 (p38(Y323)). Here we characterize knockin mice in which p38α and/or β Tyr-323 has been replaced with Phe. We find that p38α accounts for two-thirds and p38β the remainder of TCR-induced p38 activation. T cells from double knockin mice (p38αβ(Y323F)) had defects in TCR-mediated proliferation and Th1 and Th17 skewing, the former corresponding with an inability to sustain T-bet expression. Introduction of p38α(Y323F) into Gadd45α-deficient mice, in which the alternative p38 pathway is constitutively active, reversed T-cell hyperproliferation and autoimmunity. Furthermore, p38αβ(Y323F) mice had delayed onset and reduced severity of the inflammatory autoimmune diseases collagen-induced arthritis and experimental autoimmune encephalomyelitis. Thus, T cell-specific alternative activation of p38 is an important pathway in T-cell proliferation, Th skewing, and inflammatory autoimmunity, and may be an attractive tissue-specific target for intervention in these processes.

Immune response to Aspergillus fumigatus in compromised hosts: from bedside to bench

The relevance of studies aimed at understanding host immune response against Aspergillus fumigatus takes on much significance given that all patients with invasive aspergillosis are invariably immunocompromised. This article attempts to correlate relevant findings from recent experimental studies to clinical observations made by the physician at the bedside. It is hoped that the increased understanding of host-fungus immune interaction may pave the way for the development of new management strategies against this difficult-to-treat fungal disease.

Tumor necrosis factor inhibits glucocorticoid receptor function in mice: a strong signal toward lethal shock

As glucocorticoid resistance (GCR) and the concomitant burden pose a worldwide problem, there is an urgent need for a more effective glucocorticoid therapy, for which insights into the molecular mechanisms of GCR are essential. In this study, we addressed the hypothesis that TNFα, a strong pro-inflammatory mediator in numerous inflammatory diseases, compromises the protective function of the glucocorticoid receptor (GR) against TNFα-induced lethal inflammation. Indeed, protection of mice by dexamethasone against TNFα lethality was completely abolished when it was administered after TNFα stimulation, indicating compromised GR function upon TNFα challenge. TNFα-induced GCR was further demonstrated by impaired GR-dependent gene expression in the liver. Furthermore, TNFα down-regulates the levels of both GR mRNA and protein. However, this down-regulation seems to occur independently of GC production, as TNFα also resulted in down-regulation of GR levels in adrenalectomized mice. These findings suggest that the decreased amount of GR determines the GR response and outcome of TNFα-induced shock, as supported by our studies with GR heterozygous mice. We propose that by inducing GCR, TNFα inhibits a major brake on inflammation and thereby amplifies the pro-inflammatory response. Our findings might prove helpful in understanding GCR in inflammatory diseases in which TNFα is intimately involved.

Wnt-4 protects thymic epithelial cells against dexamethasone-induced senescence

Glucocorticoids are widely used immunosuppressive drugs in treatment of autoimmune diseases and hematological malignancies. Glucocorticoids are particularly effective immune suppressants, because they induce rapid peripheral T cell and thymocyte apoptosis resulting in impaired T cell-dependent immune responses. Although glucocorticoids can induce apoptotic cell death directly in developing thymocytes, how exogenous glucocorticoids affect the thymic epithelial network that provides the microenvironment for T cell development is still largely unknown. In the present work, we show that primary thymic epithelial cells (TECs) express glucocorticoid receptors and that high-dosage dexamethasone induces degeneration of the thymic epithelium within 24 h of treatment. Changes in organ morphology are accompanied by a decrease in the TEC transcription factor FoxN1 and its regulator Wnt-4 parallel with upregulation of lamina-associated polypeptide 2α and peroxisome proliferator activator receptor γ, two characteristic molecular markers for adipose thymic involution. Overexpression of Wnt-4, however, can prevent upregulation of adipose differentiation-related aging markers, suggesting an important role of Wnt-4 in thymic senescence.

Effect of dexamethasone on Na+/Ca2+exchanger in dendritic cells

Ca+-dependent signaling regulates the function of dendritic cells (DCs), antigen-presenting cells linking innate and adaptive immunity. The activity of DCs is suppressed by glucocorticoids, potent immunosuppressive hormones. The present study explored whether the glucocorticoid dexamethasone influences the cytosolic Ca2+concentration ([Ca2+]i) in DCs. To this end, DCs were isolated from mouse bone marrow. According to fura-2 fluorescence, exposure of DCs to lipopolysaccharide (LPS, 100 ng/ml) increased [Ca2+]i, an effect significantly blunted by overnight incubation with 10 nM dexamethasone before LPS treatment. Dexamethasone did not affect the Ca2+content of intracellular stores, sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA)2 and SERCA3 expression, ryanodine receptor (RyR)1 expression, or Ca2+entry through store-operated Ca2+channels. In contrast, dexamethasone increased the transcript level and the membrane protein abundance of the Na+/Ca2+exchanger NCX3. The activity of Na+/Ca2+exchangers was assessed by removal of extracellular Na+in the presence of external Ca2+, a maneuver triggering the Ca2+influx mode. Indeed, Na+removal resulted in a rapid transient increase of [Ca2+]iand induced an outwardly directed current as measured in whole cell patch-clamp experiments. Dexamethasone significantly augmented the increase of [Ca2+]iand the outward current following removal of extracellular Na+. The NCX blocker KB-R7943 reversed the inhibitory effect of dexamethasone on LPS-induced increase in [Ca2+]i. Dexamethasone blunted LPS-induced stimulation of CD86 expression and TNF-α production, an effect significantly less pronounced in the presence of NCX blocker KB-R7943. In conclusion, our results show that glucocorticoid treatment blunts LPS-induced increase in [Ca2+]iin DCs by increasing expression and activity of Na+/Ca2+exchanger NCX3. The effect contributes to the inhibitory effect of the glucocorticoid on DC maturation.

Minireview: Glucocorticoids in autoimmunity: unexpected targets and mechanisms

For decades, natural and synthetic glucocorticoids (GC) have been among the most commonly prescribed classes of immunomodulatory drugs. Their unsurpassed immunosuppressive and antiinflammatory activity along with cost-effectiveness makes these compounds a treatment of choice for the majority of autoimmune and inflammatory diseases, despite serious side effects that frequently accompany GC therapy. The activated GC receptor (GR) that conveys the signaling information of these steroid ligands to the transcriptional machinery engages a number of pathways to ultimately suppress autoimmune responses. Of those, GR-mediated apoptosis of numerous cell types of hematopoietic origin and suppression of proinflammatory cytokine gene expression have been described as the primary mechanisms responsible for the antiinflammatory actions of GC. However, along with the ever-increasing appreciation of the complex functions of the immune system in health and disease, we are beginning to recognize new facets of GR actions in immune cells. Here, we give a brief overview of the extensive literature on the antiinflammatory activities of GC and discuss in greater detail the unexpected pathways, factors, and mechanisms that have recently begun to emerge as novel targets for GC-mediated immunosuppression.

Ca2+ signaling in the regulation of dendritic cell functions

Dendritic cells (DCs) are highly versatile antigen-presenting cells critically involved in both innate and adaptive immunity as well as maintenance of self-tolerance. DC function is governed by Ca(2+) signaling, which directs the DC responses to diverse antigens, including Toll-like receptor ligands, intact bacteria, and microbial toxins. Ca(2+)-sensitive DC functions include DC activation, maturation, migration, and formation of immunological synapses with T cells. Moreover, alterations of cytosolic Ca(2+) trigger immune suppression or switch off DC activity. Ca(2+) signals are generated by the orchestration of Ca(2+) transport processes across plasma, endoplasmic reticulum, and inner mitochondrial membrane. These processes include active pumping of Ca(2+), Ca(2+)/Na(+) antiport, and electrodiffusion through Ca(2+)-permeable channels or uniporters. Ca(2+) channels in the plasma membrane such as Ca(2+) release-activated Ca(2+) or L-type Ca(2+) channels are tightly regulated by the membrane potential which in turn depends on the activity of voltage-gated K(+) or Ca(2+)-activated nonselective cation channels. The rapidly growing knowledge on the function and regulation of these membrane transport proteins provides novel insight into pathophysiological mechanisms underlying dysfunction of the immune system and opens novel therapeutic opportunity to favorably influence the function of the immune system.

Aristolochic acid nephropathy revisited: a place for innate and adaptive immunity?

AIMS

The histological features of aristolochic acid nephropathy (AAN) consist of paucicellular interstitial fibrosis, severe tubular atrophy, and almost intact glomeruli with media lesions of interlobular arteries. As an early phase of interstitial inflammation preceded peritubular fibrosis in the rat model of AAN, the aim was to investigate the presence of inflammatory cells in human AAN.

METHODS AND RESULTS

Reports of confirmed cases and case series of AAN were reviewed in terms of interstitial inflammation and found to have very conflicting results. This prompted us to search for and characterize inflammatory cells within the native kidneys provided from four end-stage AAN patients. Prior aristolochic acid exposure was attested by the intrarenal presence of the typical aristolactam I-derived DNA adduct. Besides the tubulointerstitial lesions usually seen in the cortex, a massive infiltration of macrophages, T and B lymphocytes was detected by immunohistochemistry in the medullary rays and in the outer medullae with some extension to the upper cortical labyrinth.

CONCLUSIONS

In parallel with histological findings reported in the rat model, inflammatory cells are present preferentially in the interstitium of the medullary rays and of the outer medulllae in renal interstitium from human AAN cases, even in the terminal stages. Further studies must be undertaken to determine the respective roles of innate and adaptive immunity in the progression of AAN.

Psychological stress during exercise: immunoendocrine and oxidative responses

The purpose of this study was to examine the changes in catecholamines (epinephrine [EPI] and norepinephrine [NE]), interleukin-2 (IL-2) and a biomarker of oxidative stress (8-isoprostane) in healthy individuals who were exposed to a dual challenge (physical and psychological stress). Furthermore, this study also examined the possible relationships between catecholamines (NE and EPI) and 8-isoprostane and between IL-2 and 8-isoprostane following a combined physical and psychological challenge. Seven healthy male subjects completed two experimental conditions. The exercise-alone condition (EAC) consisted of cycling at 60% VO(2max) for 37 min, while the dual-stress condition (DSC) included 20 min of a mental challenge while cycling. DSC showed greater EPI and 8-isoprostane levels (significant condition by time interaction). NE and IL-2 revealed significant change across time in both conditions. In addition, following dual stress, EPI area-under-the-curve (AUC) demonstrated a positive correlation with NE AUC and IL-2 AUC. NE AUC was positively correlated with IL-2 AUC and peak 8-isoprostane, and peak IL-2 was positively correlated with peak 8-isoprostane in response to a dual stress. The potential explanation for elevated oxidative stress during dual stress may be through the effects of the release of catecholamines and IL-2. These findings may further provide the potential explanation that dual stress alters physiological homeostasis in many occupations including firefighting, military operations and law enforcement. A greater understanding of these responses to stress can assist in finding strategies (e.g. exercise training) to overcome the inherent psychobiological challenges associated with physically and mentally demanding professions.

Biobehavioral factors and cancer progression: physiological pathways and mechanisms

Epidemiologic evidence increasingly has supported the role of biobehavioral risk factors such as social adversity, depression, and stress in cancer progression. This review describes in vitro, in vivo, and clinical studies demonstrating relationships between such processes and pathways involved in cancer progression. These include effects on the cellular immune response, angiogenesis, invasion, anoikis, and inflammation. Biobehavioral factors have been shown to contribute to the cross talk between tumor and host cells in the tumor microenvironment, and stress effects on host cells such as macrophages seem to be critical for many pathways involved in tumor progression. Some effects are bidirectional in that tumor-derived inflammation seems to affect central nervous system processes, giving rise to vegetative symptoms and contributing to dysregulation of the hypothalamic-pituitary-adrenal axis with downstream effects on inflammatory control. Findings to date are reviewed, and fruitful areas for future research are discussed.

Intestinal microsporidiosis: a hidden risk in rheumatic disease patients undergoing anti-tumor necrosis factor therapy combined with disease-modifying anti-rheumatic drugs?

OBJECTIVE

Immunosuppressed patients are at risk of microsporidiosis, and this parasitosis has an increased rate of dissemination in this population. Our objective was to evaluate the presence of microsporidiosis and other intestinal parasites in rheumatic disease patients undergoing anti-tumor necrosis factor/disease-modifying anti-rheumatic drug treatment.

METHODS

Ninety-eight patients (47 with rheumatoid arthritis, 31 with ankylosing spondylitis and 11 with psoriatic arthritis) and 92 healthy control patients were enrolled in the study. Three stool samples and cultures were collected from each subject.

RESULTS

The frequency of microsporidia was significantly higher in rheumatic disease patients than in control subjects (36 vs. 4%, respectively; p<0.0001), as well as in those with rheumatic diseases (32 vs. 4%, respectively; p<0.0001), ankylosing spondylitis (45 vs. 4%, respectively; p<0.0001) and psoriatic arthritis (40 vs. 4%, respectively; p<0.0001), despite a similar social-economic class distribution in both the patient and control groups (p = 0.1153). Of note, concomitant fecal leukocytes were observed in the majority of the microsporidia-positive patients (79.5%). Approximately 80% of the patients had gastrointestinal symptoms, such as diarrhea (26%), abdominal pain (31%) and weight loss (5%), although the frequencies of these symptoms were comparable in patients with and without this infection (p>0.05). Rheumatoid arthritis, ankylosing spondylitis and psoriatic arthritis disease activity parameters were comparable in both groups (p>0.05). The duration of anti-tumor necrosis factor/disease-modifying anti-rheumatic drugs and glucocorticoid use were also similar in both groups.

CONCLUSION

We have documented that microsporidiosis with intestinal mucosa disruption is frequent in patients undergoing concomitant anti-tumor necrosis factor/disease-modifying anti-rheumatic drug therapy. Impaired host defenses due to the combination of the underlying disease and the immunosuppressive therapy is the most likely explanation for this finding, and this increased susceptibility reinforces the need for the investigation of microsporidia and implementation of treatment strategies in this population.

Altered immunomodulation by glucocorticoids in neonatal pigs exposed to a psychosocial stressor

Stressful early life experiences can have short- and long-term effects on neuroendocrine and immune mechanisms of adaptation, which are primarily modulated by glucocorticoids. This study aimed to examine how the stress and immune systems interact to cope with psychosocial stress induced by a single social isolation (4 h) in neonatal pigs at 7, 21, or 35 d of age. This social isolation provoked increased plasma ACTH and cortisol concentrations and reduced TNF-α levels but had no significant effect on IL-6 levels. Socially isolated piglets had a higher lipopolysaccharide (LPS)-stimulated proliferative response of peripheral blood mononuclear cells (PBMCs) than controls, whereas concanavalin A (ConA)-induced proliferation was not affected by isolation. A single social isolation also induced a dose-dependent cortisol resistance in ConA- and LPS-stimulated PBMCs compared with controls, which may be an adaptive response in the short term. Moreover, LPS-stimulated cultures from control piglets showed a reduction in cortisol sensitivity with increasing age. Conclusively, these findings provide stress-related measures for the psychophysiological assessment of livestock handling practices but might also have implications for stress and health studies in young animals and humans.

Surgery as a double-edged sword: a clinically feasible approach to overcome the metastasis-promoting effects of surgery by blunting stress and prostaglandin responses

Surgery remains an essential therapeutic approach for most solid malignancies, including breast cancer. However, surgery also constitutes a risk factor for promotion of pre-existing micrometastases and the initiation of new metastases through several mechanisms, including the release of prostaglandins and stress hormones (e.g., catecholamines and glucocorticoids). However, the perioperative period also presents an opportunity for cell mediated immunity (CMI) and other mechanisms to eradicate or control minimal residual disease, provided that the deleterious effects of surgery are minimized. Here, we discuss the key role of endogenous stress hormones and prostaglandins in promoting the metastatic process through their direct impact on malignant cells, and through their deleterious impact on anti-cancer CMI. We further discuss the effects of anesthetic techniques, the extent of surgery, pain alleviation, and timing within the menstrual cycle with respect to their impact on tumor recurrence and physiological stress responses. Last, we suggest an attractive perioperative drug regimen, based on a combination of a cyclooxygenase (COX)-2 inhibitor and a β-adrenergic blocker, which we found effective in attenuating immune suppression and the metastasis-promoting effects of surgery in several tumor models. This regimen is clinically applicable, and could potentially promote disease free survival in patients operated for breast and other types of cancer.

Healthy working school teachers with high effort-reward-imbalance and overcommitment show increased pro-inflammatory immune activity and a dampened innate immune defence

To test whether chronic work stress is accompanied by altered immune functioning, changes in lymphocyte subsets and in lymphocyte production of cytokines were examined in reaction to acute psychosocial stress. Work stress was measured according to Siegrist's effort-reward-imbalance (ERI) model. ERI reflects stress due to a lack of reciprocity between costs and gains at work. Overcommitment (OC) is conceptualized as a dysfunctional coping pattern mainly characterized by the inability to withdraw from work obligations. Fifty-five healthy teachers (34 women, 21 men, mean age 50.0 ± 8.47 years) were exposed to a standardized laboratory stressor (Trier Social Stress Test). Lymphocyte subset counts and lymphocyte production of tumor-necrosis-factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-2, -4, -6 and -10 were measured before and after challenge. High levels of ERI and OC were associated with lower natural killer (NK) cell (CD16+/56+) numbers whereas high levels of OC were related to a lower increase in T-helper cells (CD4+) after stress. Furthermore, subjects with higher ERI showed an overall increased pro-inflammatory activity, with higher TNF-α production at both time points and elevated pre-stress IL-6 production. IL-10 production decreased with higher ERI after stress. The ratios of TNF-α/IL-10 and IL-6/IL-10 were significantly increased in subjects high on ERI. Finally, OC was associated with higher IL-2 production post-stress. The present findings suggest a dampened innate immune defence, reflected in lower NK cell numbers together with an increased pro-inflammatory activity in teachers high on ERI and OC. Such pathways could partly be responsible for the increased vulnerability for stress-related diseases in individuals suffering from chronic work stress.

In vivo efficacy of dendrimer-methylprednisolone conjugate formulation for the treatment of lung inflammation

Dendrimers are an emerging class of nanoscale intracellular drug delivery vehicles. Methylprednisolone (MP) is an important corticosteroid used in the treatment (through inhalation) of lung inflammation associated with asthma. The ability of MP-polyamidoamine (PAMAM) dendrimer conjugate to improve the airway delivery was evaluated in a pulmonary inflammatory murine model that was based on an 11-fold enhancement of eosinophil lung accumulation following five daily inhalation exposures of sensitized mice to the experimental allergen, ovalbumin. MP was successfully conjugated to PAMAM-G4-OH dendrimer yielding 12 MP molecules per dendrimer, and further solubilized in lysine carrier. Five daily trans-nasal treatments with the carrier alone, free MP, and MP-dendrimer at 5 mg kg(-1) (on a drug basis) did not induce additional lung inflammation, although free MP decreased baseline phagocytic cell recoveries by airway lavage and tissue collagenase dispersion. MP treatments alone decreased ovalbumin-associated airway and tissue eosinophil recoveries by 71 and 47%, respectively. Equivalent daily MP dosing with MP-dendrimer conjugate further diminished these values, with decreases of 87% and 67%, respectively. These findings demonstrate that conjugation of MP with a dendrimer enhances the ability of MP to decrease allergen-induced inflammation, perhaps by improving drug residence time in the lung. This is supported by the fact that only 24% of a single dose of dendrimer delivered to the peripheral lung is lost over a 3-day period. Therefore, conjugation of drugs to a dendrimer may provide an improved method for retaining drugs within the lung when treating such inflammatory disorders as asthma.

T cells from burn-injured mice demonstrate a loss of sensitivity to glucocorticoids

Glucocorticoids (GC) are steroid hormones that modulate T cell functions and restrain their hyperresponsiveness following stimulation. Naive T lymphocytes are sensitive to GC but become more resistant when they are activated. A balance between activation and inhibition signals is important for a targeted and effective T cell response. Thermal injury is characterized by an immune dysfunction and hyperactive T cells visible at day 10 postburn. In this study, our objective was to evaluate T cell sensitivity to GC following thermal injury and to identify mechanisms that could modulate their sensitivity. One mechanism that we hypothesized was increased p38 mitogen-activated protein kinase (MAPK) activity that could lead to GC resistance. Male C57BL/6 mice underwent a full-thickness 20% total body surface area. At 10 days postinjury, splenic T cells were isolated. Glucocorticoid receptor (GR) expression was higher in T cells from burn-injured mice. Interestingly, these cells were also less sensitive to GC-induced apoptosis prior to and poststimulation. Furthermore, anti-CD3-activated T cells from burn-injured mice showed increased proliferation and CD25 expression, which resisted corticosterone's (CORT) suppressive effect. Anti-CD3-activated CD4(+)CD44(+) memory cells from burn-injured mice expressed the highest level of CD25 and were resistant to CORT. Increased phosphorylation of p38 MAPK was also noted in activated T cells from burn-injured mice. Pharmacological inhibition of p38 MAPK decreased cell proliferation and normalized interferon-gamma (IFNgamma) production. In conclusion, we demonstrate that a unique event like burn injury induces a loss of sensitivity to GC in splenic T cells and have identified p38 MAPK as a key modulator for this resistance.

Inflammation and cerebral vasospasm after subarachnoid hemorrhage

Morbidity and mortality of patients with aneurysmal subarachnoid hemorrhage (aSAH) is significantly related to the development of chronic cerebral vasospasm. Despite extensive clinical and experimental research, the pathophysiology of the events that result in delayed arterial spasm is not fully understood. A review of the published literature on cerebral vasospasm that included but was not limited to all PubMed citations from 1951 to the present was performed. The findings suggest that leukocyte-endothelial cell interactions play a significant role in the pathophysiology of cerebral vasospasm and explain the clinical variability and time course of the disease. Experimental therapeutic targeting of the inflammatory response when timed correctly can prevent vasospasm, and supplementation of endothelial relaxation by nitric oxide-related therapies and other approaches could result in reversal of the arterial narrowing and improved outcomes in patients with aSAH.

Use of saliva for assessment of stress and its effect on the immune system prior to gross anatomy practical examinations

The objective of this study was to determine the longitudinal effects of a series of stressful gross anatomy tests on the immune system. Thirty-six freshman occupational therapy students completed a written stress evaluation survey, and saliva samples were obtained at baseline and prior to each of three timed-practical gross anatomy tests. Cortisol, secretory IgA (sIgA), and IL-12 concentrations were measured within the salivary samples by enzyme-linked immunosorbent assay. The total scores from the stress surveys were used as markers for environmental stress. Data were compiled for each student at baseline and prior to each examination and were compared by repeated-measures MANOVA and Pearson's correlation test. Following normalization for protein concentration and flow rate, the concentrations of IL-2, IL-6, IL-12, and sIgA progressively increased from baseline to the third test. Cortisol concentrations, following normalization for flow rate, were highest prior to the first test and became significantly reduced prior to second and third test. Prior to second and third test, salivary concentrations of IL-6, IL-2, IL-12, and sIgA were significantly correlated (P < 0.05). In contrast, prior to third test, there was a negative correlation between salivary concentrations of cortisol and IL-12 (P < 0.05). Progressive increases in salivary sIgA, IL-6, IL-2, and IL-12 concentrations from the first to the third test coincident to decreased salivary cortisol suggest that the initial examination stressors precede significant effects on the immune system. These data suggest that there may be latent effects of examination stress on the immune system and that saliva can be used to predict these effects.

Anti-Emetic Dexamethasone and Postoperative Infection Risk: A Retrospective Cohort Study

Nausea and vomiting are common complications of anaesthesia. Dexamethasone is an effective prophylaxis but is immunosuppressive and may increase postoperative infection risk. This retrospective cohort study examined the association between the administration of a single intraoperative anti-emetic dose of dexamethasone (4 to 8 mg) and postoperative infection in 439 patients undergoing single procedure, non-emergency surgery in a university trauma centre. Exclusion criteria included comorbidities, immunosuppressive medications or procedures that confer an increased infection risk. In the 10-week study period and three-month follow-up period, there were 98 documented infections (22.3% of the cohort), of which 43 were detected only on post-discharge follow-up. Anti-emetic dexamethasone was given to 108 patients (24.6%). Stepwise, multivariate logistic regression modelling identified significant associations between female gender, symptomatic reflux, respiratory disease and the risk of infection. The adjusted odds ratio for dexamethasone was 0.88 (0.5 to 1.5, P=0.656). We did not demonstrate an association between anti-emetic doses of dexamethasone and postoperative infection.

Understanding stress-induced immunosuppression: exploration of cytokine and chemokine gene profiles in chicken peripheral leukocytes

At present, the poultry meat and egg industry has gained a lot of ground, being viewed as a provider of a healthy alternative to red meat and other protein sources. If this trend is to be maintained, solutions must be found to improve resistance of chickens to disease, which often is weakened by stressful conditions. In poultry, stress-induced immunosuppression is manifested by failures in vaccination and increased morbidity and mortality of flocks. Currently, several modern cellular and molecular approaches are being used to explore the status of the immune system during stress and disease. It is likely that these new techniques will lead to the development of new strategies for preventing and controlling immunosuppression in poultry. Using quantitative reverse transcription-PCR assays, a broad spectrum of cytokine, chemokine, and their receptor genes can be quantified in birds and then be used as markers to assess the effects of stress on the immune system. Currently, we are investigating immune and endocrine interactions in the chicken, in particular the cells and molecules that are known to be involved in such interactions in mammals. We have evaluated the effects of corticosterone administration in drinking water on peripheral lymphocyte and heterophil cytokine and chemokine gene profiles. In particular, there seems to be effects on cytokine and chemokine mRNA expression levels in both lymphocytes and heterophils, especially expression of the proinflammatory cytokines interleukin (IL)-1beta, IL-6, and IL-18 and chemokines C-C motif, ligand 1 inflammatory (CCLi1); C-C motif, ligand 2 inflammatory (CCLi2); C-C motif, ligand 5 (CCL5); C-C motif, ligand 16 (CCL16); C-X-C motif ligand 1 inflammatory (CXCLi1); and C-X-C motif ligand 2 inflammatory (CXCLi2), which are initially upregulated and are potentially involved in modulating the adaptive immune response. A chronic treatment with corticosterone downregulates proinflammatory cytokines and chemokines, suggesting that the delayed effects of chronic stress can suppress the immune response. Messenger RNA expression levels of transforming growth factor-beta4 (TGF-beta4) are also upregulated in cortisosterone-treated birds. It appears that the balance between T-helper (Th) 1 and Th2/T regulatory cytokine production is altered in conditions associated with significant changes in plasma corticosterone concentration. Experiments are underway to decipher the cytokine and chemokine responses to vaccination and bacterial challenge on the background of stress-induced immunosuppression.

Differential expression of two glucocorticoid receptors in seabass (teleost fish) head kidney after exogeneous cortisol inoculation

Stressful conditions include a prompt release of corticosteroid hormones which can mediate gene expression through glucocorticoid receptors (GR). Since two seabass (Dicentrarchus labrax) GRs have been cloned and sequenced from peritoneal cavity cells (DlGR1) and liver (DlGR2), a comparative amino acid sequence analysis that included Haplochromis burtoni HbGRs, was carried out and homologies disclosed. The DlGR1 and DlGR2 deduced aminoacid sequences showed 61% identity (I) and 70% similarity (S). Moreover, DlGR2 was similar to HbGR2b (69% I, 73% S), and the DlGR1 to HbGR1 (72% I, 78% S). In addition, we examined the expression of the DlGRs after exogeneous cortisol inoculation into the peritoneal cavity, mimicking stress effects. At various times after the administration (3 h, 24 h, 1 week), gene expressions was evaluated in head kidney by real-time PCR. In addition, immunoblotting and densitometry analyses were performed with anti-DlGR1 antibodies. Although sea bass head kidney expressed both DlGR1 and DlGR2 they were differentially modulated by intraperitoneal implant of exogeneous cortisol.