Stress system activity, innate and T helper cytokines, and susceptibility to immune-related diseases

Nonimmune cells in inflammatory bowel disease: from victim to villain

Nonimmune cells have traditionally been viewed as target cells of the aberrant inflammatory process present in chronic immune-mediated conditions such as inflammatory bowel disease (IBD). However, the discovery that many of the functions traditionally attributed to immune cells are also performed by nonimmune cells has caused a shift to a multidirectional hypothesis in which nonimmune cells and acellular elements play active roles. Many types of interactions occur within this multidirectional system, and the difficulties associated with modeling these complex interactions currently limit our understanding of the cellular network that occurs in IBD. I describe the current knowledge of the roles played by nonimmune cells in the pathogenesis of IBD, as they emerge as crucial alternative targets for therapeutic intervention.

Preliminary evidence of a genetic association between tumor necrosis factor alpha and the severity of sleep disturbance and morning fatigue

Although fatigue and sleep disturbance are prevalent symptoms in oncology patients and their family caregivers, little is known about the factors that contribute to interindividual variability in symptom severity ratings as well as in their underlying biological mechanisms. In this study, we sought to determine whether a functional genetic variation in a prominent proinflammatory cytokine, tumor necrosis factor-alpha (TNFA-308G>A [rs1800629] promoter polymorphism) was associated with overall ratings of sleep disturbance and fatigue as well as with the trajectories of these symptoms. Over 6 months, participants completed standardized measures of sleep disturbance and fatigue. Multiple linear regression was used to assess the effect of the TNFA genotype and other covariates on mean sleep disturbance and fatigue scores. Hierarchical linear modeling was used to determine the effect of TNFA genotype on the trajectories of these symptoms. Common allele homozygotes reported higher levels of sleep disturbance (p=.09) and morning fatigue (p=.02) than minor allele carriers. Multivariate analyses demonstrated that age and genotype were predictors of both mean symptom scores and the trajectories of these symptoms. Findings provide preliminary evidence of an association between a functional promoter polymorphism in the TNFA gene and the severity of sleep disturbance and morning fatigue in oncology patients and their family caregivers.

Adiponectin protects against cerebral ischemia-reperfusion injury through anti-inflammatory action

Adiponectin (APN), a circulating adipose-derived hormone regulating inflammation and energy metabolism, has beneficial actions on cardio- and cerebrovascular disorders. Hypoadiponectinemia is associated with ischemic cerebrovascular disease, however, little is known about the cerebroprotective action of APN as well as its molecular mechanisms. In the present study, the role of APN in the pathogenesis of acute cerebral injury was investigated. Rats were divided into three groups: (i) a sham operation group; (ii) an ischemia/reperfusion (I/R) group, rats were subjected to 1 h middle cerebral artery occlusion followed by 23 h reperfusion (I/R); (iii) a APN-treated group, two bolus of 5 microg APN was administered through jugular vein before and after operation. I/R resulted in obvious cerebral infarct size, neurological deficits, and increased expression of endogenous immunoglobin G and matrix metalloproteinase 9, which can be significantly diminished by administration of APN. We also found that APN can significantly inhibited cerebral expression of myeloperoxidase, a distinct indicator of inflammatory cell infiltration, and inflammatory cytokines, interleukin (IL)-1beta, tumor necrosis factor-alpha and IL-8 in response to I/R, suggesting that APN exerts potent anti-inflammatory actions. Furthermore, nuclear factor (NF)-kappaB (p65), a critical transcription factor involved in inflammatory reactions, was observed predominantly located in the nucleus after I/R, whereas APN can obviously inhibit its translocation from cytoplasm into the nucleus. Results of this study demonstrate that APN exerts a potent cerebroprotective function through its anti-inflammatory action, and NF-kappaB (p65) is a key component in this process. APN might be potential molecular targets for ischemic stroke therapy.

Increased phospholipase A2 activity and inflammatory response but decreased nerve growth factor expression in the olfactory bulbectomized rat model of depression: effects of chronic ethyl-eicosapentaenoate treatment

An increased inflammatory response and deficient synthesis of neurotrophic factors (NTFs) may contribute to the etiology of depression. However, the interrelationship between inflammation and NTFs is unknown. Recently, ethyl-eicosapentaenoate (EPA) has been used to treat depression. The mechanism by which EPA benefits depression is also unclear. Using the olfactory bulbectomized (OB) rat model of depression, this study evaluated two pathways from bulbectomy to the induction of depression-like changes (the inflammation-hypothalamic-pituitary-adrenal axis-stress response pathway and inflammation-nerve growth factor-memory pathway) and the effect of EPA on these pathways. When compared with sham-operated rats fed a control diet, significantly increased locomotor and rearing activities in an "open field," impaired memory in the Morris water maze, increased expression of corticotrophin-releasing factor (CRF), and increased secretion of corticosterone were found in OB rats. mRNA expression of nerve growth factor (NGF) was significantly lower in the hippocampus, and phospholipase A2 (PLA2) was higher in the hypothalamus; this change was associated with increased interleukin-1beta (IL-1beta) and prostaglandin E2 (PGE2) in the serum and brain. EPA treatments normalized these behavioral impairments and reduced CRF expression and corticosterone secretion. EPA also reduced serum concentrations of IL-1beta and PGE2, but reversed NGF reduction. Similar to the effects of EPA, the anti-inflammatory drug celecoxib significantly reduced blood PGE2, IL-1beta, and corticosterone concentrations and increased NGF expression in OB rats. Furthermore, anti-NGF treatment blocked EPA effects on behavior. These results suggest that an interaction exists between inflammation and NGF in the depression model. EPA may improve depression via its anti-inflammation properties and the upregulation of NGF.

Candidate genes for respiratory disease associated with markers of inflammation and endothelial dysfunction in elderly men

BACKGROUND

Inflammation and endothelial dysfunction are important risk factors for cardiovascular disease (CVD). We hypothesized that candidate genes selected for a study of asthma and chronic obstructive pulmonary disorder (COPD) are associated with markers of systemic inflammation and endothelial dysfunction in an aging population.

METHODS

Plasma levels of circulating C-reactive protein (CRP), fibrinogen, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were obtained from 679 elderly male participants in the Normative Aging Study. Blood samples were analyzed for 202 single nucleotide polymorphisms (SNPs) in 25 candidate genes and included both haplotype tagSNPs and functional SNPs based on literature review. Data were stratified into discovery and replication cohorts for 2-stage analysis. In the discovery cohort, the relationship between biomarker level and genotype was analyzed using linear mixed effects with random intercepts for each subject and models were adjusted for age and BMI. A positive outcome in the discovery cohort was defined as a p-value <0.1 for the SNP. SNPs that met this criterion were analyzed in the replication cohort and confirmed for those which met a criterion of significance (p<0.025).

RESULTS

In our analyses, SNPs in the CRHR1, ITPR2, and VDR genes met significance criteria.

CONCLUSIONS

Our results suggest that genes thought to play a role in the pathogenesis of asthma and COPD may influence levels of serum markers of inflammation and endothelial dysfunction via novel SNP associations which have not previously been associated with cardiovascular disease.

Plasma osteopontin modulates chronic restraint stress-induced thymus atrophy by regulating stress hormones: inhibition by an anti-osteopontin monoclonal antibody

Osteopontin (OPN) is a cytokine implicated in mediating responses to certain stressors, including mechanical, oxidative, and cellular stress. However, the involvement of OPN in responding to other physical and psychological stress is largely unexplored. Our previous research revealed that OPN is critical for hind limb-unloading induced lymphoid organ atrophy through modulation of corticosteroid production. In this study, we demonstrate that OPN(-/-) mice are resistant to chronic restraint stress (CRS)-induced lymphoid (largely thymus) organ atrophy; additionally, the stress-induced up-regulation of corticosterone production is significantly reduced in OPN(-/-) mice. Underlying this observation is the fact that normal adrenocorticotropic hormone levels are substantially reduced in the OPN(-/-) mice. Our data demonstrate both that injection of OPN into OPN-deficient mice enhances the CRS-induced lymphoid organ atrophy and that injection of a specific anti-OPN mAb (2C5) into wild-type mice ameliorates the CRS-induced organ atrophy; changes in corticosterone levels were also partially reversed. These studies reveal that circulating OPN plays a significant role in the regulation of the hypothalamus-pituitary-adrenal axis hormones and that it augments CRS-induced organ atrophy.

Chronic restraint stress impairs T-cell immunity and promotes tumor progression in mice

Long-term exposure to stressful situations can affect the immune system. The T-cell response is an important component of anti-tumoral immunity. Hence, impairment of the immune function induced by a chronic stressor has been postulated to alter the immunosurveillance of tumors, thus leading to a worse neoplastic prognosis. Here, we show that chronic restraint stress affects T-cell mediated immunity in mice. This was evidenced by a decrease of mitogen-induced T-cell proliferation, a reduction in CD4(+)T lymphocyte number and a decrease of tumor necrosis factor-alpha (TNF-alpha) and Interferon-gamma (IFN-gamma) production in stressed mice. Additionally, mice subjected to chronic restraint stress displayed an enhancement of tumor growth in a syngeneic lymphoma model, i.e. an increase of tumor proliferation and a reduction of animal survival. Finally, stressed mice had a reduced specific cytotoxic response against these tumor cells. These results suggest that chronic exposure to stress promotes cancer establishment and subsequent progression, probably by depressing T-cell mediated immunity. The T-cell immunity impairment as well as the tumor progression enhancement emphasize the importance of the therapeutic management of stress to improve the prognosis of cancer patients.

Immunomodulatory effects of Abnormal Savda Munsiq, a traditional Uighur medicine, on the combined stress mice

OBJECTIVE

To investigate the immunomodulatory effects of ASMq, a herbal preparation used in Traditional Uighur Medicine, on the combined stress mice.

MATERIALS AND METHODS

The combined stress was induced on mice by application of the electric-foot shock in a cold-dry environment and three different doses of ASMq were orally administered to the animals for 14 days. The effect of ASMq on the immune apparatus weight index, lymphocytes proliferation, serum levels of the cytokines, immunoglobulins, hemolysin and NK cells as well as the phagocytic activity of the macrophages were evaluated.

RESULTS

Oral administration of ASMq was found to increase the thymus and spleen indices, lymphocytes proliferation induced by Con A and LPS, the percentage of CD4(+) in thymus, spleen and peripheral blood and restore the CD4(+)/CD8(+) ratio. The serum concentrations of INF-beta, IL-2, IL-6, IgG, NK cells and hemolysin were also increased. The macrophage phagocytic activity was also enhanced.

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis in irritable bowel syndrome

Enhanced stress responsiveness has been implicated as a potential mechanism contributing to the pathophysiology of irritable bowel syndrome (IBS), and should be reflected in altered function of the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system. Both of these systems can modulate mucosal immune function. The aims of this study were: (i) to characterize the basal circadian rhythm of adrenocorticotropin hormone (ACTH) and cortisol in IBS vs healthy controls; (ii) to compare stimulated ACTH, cortisol and noradrenaline responses to a pelvic visceral stressor (sigmoidoscopy) in IBS and controls; and (iii) to correlate neuroendocrine responses with colonic mucosal cytokine expression and symptoms in IBS. Two separate studies were conducted in women. In Study 1, basal cortisol levels were analysed in 41 IBS and 25 controls using 24-h collections of plasma ACTH and cortisol (q10 min sampling). In Study 2, 10 IBS patients with diarrhoea (IBS-D) and 10 controls underwent sigmoidoscopy with measurements of stimulated neuroendocrine responses and cytokine mRNA expression in colonic tissue. Basal ACTH levels were significantly blunted (P < 0.05), while basal and stimulated plasma cortisol levels were higher in patients. Basal cortisol levels prior to an experimental visceral stressor positively correlated with anxiety symptoms (P < 0.004), but not IBS symptoms. Irritable bowel syndrome patients with diarrhoea had significantly decreased mRNA expression of mucosal cytokines [interleukin (IL)-2, IL-6] in the sigmoid colon vs controls (P < 0.05). Although dysregulations in stress-responsive systems such as the HPA axis and mucosal immune function are demonstrated in IBS, they do not appear to have a primary role in modulating IBS severity and abdominal pain.

Adrenomedullary response to hypoglycemia in first-degree relatives of patients with rheumatoid arthritis

Our recent studies showed blunted adrenomedullary responses to insulin-induced hypoglycemia in premenopausal females with rheumatoid arthritis (RA) and systemic sclerosis, suggesting dysregulation of the adrenomedullary hormonal system (AMHS). Since no relationship has been found between degree of AMHS dysfunction and clinical or inflammatory parameters in those patients, we hypothesize the presence of an inherited perturbation of the AMHS. To test this hypothesis, we evaluated adrenomedullary responses to insulin-induced hypoglycemia (0.1 IU/kg) in premenopausal female subjects: 17 glucocorticoid-naïve RA patients, 15 healthy first-degree family members (FDR), and 18 age- and body mass index-matched healthy controls. Our results demonstrate that when compared to controls, RA patients had lower baseline epinephrine levels (P= 0.01) and lower area under response curve (AUC) levels of norepinephrine (P < 0.001) and epinephrine (P < 0.003). In contrast, FDR had lower (P= 0.001) AUC levels of norepinephrine compared to controls and higher (P= 0.033) AUC levels of epinephrine compared to RA patients. There were no significant differences in epinephrine response between FDR and controls. Although we found lower norepinephrine responses to hypoglycemia in FDR of RA patients, adrenomedullary responses to hypoglycemia does not appear to be altered to the degree found in RA patients.

Plasma lipid-dependent and -independent effects of dietary soy protein and social status on atherogenesis in premenopausal monkeys: implications for postmenopausal atherosclerosis burden

OBJECTIVE

: Atherosclerosis developed during premenopausal years predicts postmenopausal atherosclerosis burden. The objective of this study was to determine the effects of dietary soy protein isolate (SPI) and social status on atherogenesis and arterial gene expression in a premenopausal monkey model.

DESIGN

: Socially housed premenopausal cynomolgus macaques (n = 84) were fed an atherogenic diet deriving protein from casein/lactalbumin or SPI (containing 1.88 mg isoflavones/g). After 36 months of diet consumption, iliac artery biopsies were assessed for atherosclerosis and expression of mRNA transcripts related to inflammation, macrophage and T-cell content, and estrogen receptors (ERs).

RESULTS

: SPI reduced plaque size (P < 0.05), total plasma cholesterol, non-high-density lipoprotein cholesterol (HDLc), and the total plasma cholesterol/HDLc ratio (all P < 0.003), while increasing triglycerides (P < 0.006) and HDLc (P < 0.0001). Arterial mRNA for CD68 (P < 0.001), CD3 (P < 0.02), and CD4 (P < 0.001) and inflammatory markers monocyte chemotactic protein-1, intercellular adhesion molecule-1, and interleukin-6 (all P < 0.0001) were also lower in the group receiving SPI. For most outcomes, this effect remained even after adjustments for plaque size and plasma lipid concentrations. Arterial ER-alpha was inversely associated with atherosclerosis (P < 0.02) and increased with SPI (P < 0.001). Subordinate monkeys had lower ER-beta (P < 0.02) and higher interleukin-6 (P < 0.05) transcripts but did not differ from dominant monkeys in extent of atherosclerosis (P > 0.9).

CONCLUSIONS

: Premenopausal consumption of SPI had plasma lipid-independent beneficial effects on the pathobiological processes involved in atherosclerotic plaque development, thus potentially establishing the basis for reduced postmenopausal complications. Dominant social status provided similar, albeit less extensive, benefits in risk markers.

Fluoxetine directly counteracts the adverse effects of chronic stress on T cell immunity by compensatory and specific mechanisms

Chronic stress and depression are widely known to down-regulate the immune system, and several antidepressants can reverse this impairment, with or without effects in normal subjects. Although the central nervous system is undoubtedly involved in these events, some psychotropic drugs can also exert direct effects on lymphoid cells. We have recently shown that the antidepressant fluoxetine enhances T cell proliferation and T(H)1 cytokine production in vivo, without changes on CD4/CD8 subsets. In vitro, a direct action of fluoxetine upon T lymphocyte reactivity by complex mechanisms was also described. In another work, we also found that chronic stress reduces T cell mediated immunity, namely a decrease of T cell response to mitogens, T(H)1 cytokine production and CD4+-but not CD8+--T lymphocytes. Here we investigated the effects of fluoxetine on chronic stress-driven immune system depression. We found that fluoxetine restored T cell proliferation and interleukin-2, interferon-gamma and tumor necrosis factor-alpha production by compensatory mechanisms. In addition, CD4/CD8 ratio was also normalized by antidepressant administration, but this seems to be a non-compensatory effect associated specifically to stress. No changes were observed in other lymphoid cells, i.e. natural killer cells and B lymphocytes. Finally, we observed that fluoxetine is able to reverse T cell reactivity impairment in vitro by a direct action at clinically relevant doses. These results highlight the relevance of pharmacological treatment of stress and depression, and may help to begin elucidating the complex events triggered--directly and/or indirectly--by antidepressants in non-neuronal cell types.

Dysregulation of the stress response in asthmatic children

The stress system co-ordinates the adaptive responses of the organism to stressors of any kind. Inappropriate responsiveness may account for increased susceptibility to a variety of disorders, including asthma. Accumulated evidence from animal models suggests that exogenously applied stress enhances airway reactivity and increases allergen-induced airway inflammation. This is in agreement with the clinical observation that stressful life events increase the risk of a new asthma attack. Activation of the hypothalamic-pituitary-adrenal (HPA) axis by specific cytokines increases the release of cortisol, which in turn feeds back and suppresses the immune reaction. Data from animal models suggest that inability to increase glucocorticoid production in response to stress is associated with increased airway inflammation with mechanical dysfunction of the lungs. Recently, a growing body of evidence shows that asthmatic subjects who are not treated with inhaled corticosteroids (ICS) are likely to have an attenuated activity and/or responsiveness of their HPA axis. In line with this concept, most asthmatic children demonstrate improved HPA axis responsiveness on conventional doses of ICS, as their airway inflammation subsides. Few patients may experience further deterioration of adrenal function, a phenomenon which may be genetically determined.

Pneumonia as a long-term consequence of chronic psychological stress in BALB/c mice

Recently, we have shown that female BALB/c mice are highly sensitive to chronic psychological stress. They develop systemic neuroendocrine disturbances, a hypermetabolic syndrome, behavioral alterations and severe immunosuppression with a reduced antibacterial response during experimental infection. Here, we show that chronically stressed mice spontaneously suffered from increased bacterial load in the liver and lung that sustained for up to 10 days after the termination of stress exposure. Immediately after the last chronic stress cycle, splenocytes had a reduced ability to produce IFNgamma after ex vivo stimulation with LPS while showing enhanced inducibility of IL-10. When healthy animals were treated with anti-IFNgamma antiserum the antibacterial response against the small numbers of endogenous bacteria that physiologically penetrate the intestinal barrier was reduced causing increased bacterial burden in the liver. Thus, a deficient antibacterial response to translocated commensals in chronically stressed animals can contribute to long-lasting pneumonia.

Osteopontin: role in immune regulation and stress responses

Recent research has led to a better but as yet incomplete understanding of the complex roles osteopontin plays in mammalian physiology. A soluble protein found in all body fluids, it stimulates signal transduction pathways (via integrins and CD44 variants) similar to those stimulated by components of the extracellular matrix. This appears to promote the survival of cells exposed to potentially lethal insults such as ischemia/reperfusion or physical/chemical trauma. OPN is chemotactic for many cell types including macrophages, dendritic cells, and T cells; it enhances B lymphocyte immunoglobulin production and proliferation. In inflammatory situations it stimulates both pro- and anti-inflammatory processes, which on balance can be either beneficial or harmful depending on what other inputs the cell is receiving. OPN influences cell-mediated immunity and has been shown to have Th1-cytokine functions. OPN deficiency is linked to a reduced Th1 immune response in infectious diseases, autoimmunity and delayed type hypersensitivity. OPN's role in the central nervous system and in stress responses has also emerged as an important aspect related to its cytoprotective and immune functions. Evidence suggests that either OPN or anti-OPN monoclonal antibodies (depending on the circumstances) might be clinically useful in modulating OPN function. Manipulation of plasma OPN levels may be useful in the treatment of autoimmune disease, cancer metastasis, osteoporosis and some forms of stress.

Acute stress induces proinflammatory signaling at chronic inflammation sites

OBJECTIVES

To analyze in a randomized controlled study whether acute psychological stress alters local proinflammatory signals in a human model of chronic inflammation, i.e., gingivitis. Chronic inflammation represents a crucial factor in a variety of diseases and factors that contribute to the onset and progression of disease. Psychological stress is assumed to represent such a factor. However, experimental human research in this area is rare.

METHODS

A total of 25 students (n = 11 females, 14 males) suffering from gingivitis were subjected to a stress (public-speaking task) and to a control condition in randomized order. Local concentrations of interleukin (IL)-8 were quantified as an indicator of proinflammatory activity at sites of inflammation. IL-8 is a strong proinflammatory mediator and involved in a variety of disease processes. Samples were taken at sites of inflammation before stress versus control condition and 0, 45, and 90 minutes afterward.

RESULTS

A significant main effect (p = .03) of acute stress on local IL-8 was found. Stress induced an increase of IL-8-concentrations; univariate effect sizes varied between d = 0.23 and d = 0.36.

CONCLUSION

This is the first human experimental in vivo study demonstrating that psychological stress alters the local concentrations of IL-8 under conditions of chronic inflammation. It provides direct evidence acute stress is involved in the regulation of local proinflammatory responses in chronic inflammation. Future studies should now explore the effects of more enduring stress conditions and the factors mediating stress effects on inflammatory signals.

The effects of acute exercise-induced cortisol on CCR2 expression on human monocytes

CC-chemokine receptor 2 (CCR2) and its ligand, monocyte chemotactic protein-1 (MCP-1, also known as CCL2), are crucial for the recruitment of monocytes/macrophages to sites of inflammation. We conducted a series of experiments to investigate the relationship between stress, monocyte CCR2 expression and migration activity. First, we collected peripheral blood mononuclear cells (PBMC) from untrained subjects (n=8) and measured CCR2 expression on CD14(+) monocytes cultured with cortisol, epinephrine and norepinephrine. Second, we collected PBMC from the subjects before and after they cycled for 60 min at 70% peak O(2) uptake (VO2(peak)), and measured alterations in CCR2 expression on monocytes following exercise. Third, we cultured PBMC with serum obtained before and after exercise and the glucocorticoid antagonist RU-486 to determine the effect of cortisol on CCR2 expression in vitro. Last, we measured the ability of PBMC treated with serum or cortisol to migrate through membrane filters in response to CCL2. Cortisol (but not epinephrine or norepinephrine) increased CCR2 expression on monocytes in a dose- and time-dependent manner. Exercise did not influence CCR2 expression on PBMC, whereas incubation of PBMC with post-exercise serum significantly increased CCR2 expression. Both cortisol and post-exercise serum increased the migration of PBMC toward CCL2. The increase in CCR2 expression on PBMC following stimulation with cortisol and serum was blocked by the glucocorticoid receptor antagonist RU-486. In conclusion, cortisol released during exercise increased monocyte CCR2 expression and migration activity in vitro. These alterations may influence inflammation and regeneration of damaged tissue after acute stress.

Violence and Asthma: A Review

Recent research shows that exposure to community violence is, directly and indirectly, associated with asthma. This article reviews the findings on the impact of violence on asthma, and the pathways for the association of violence and asthma are suggested: 1) exposure to violence is directly associated with asthma, mainly through dysregulation of sympathetic-adrenal-medullary (SAM) and hypothalamic-pituitary-adrenal (HPA) axis, 2) exposure to violence is associated with the change of susceptibility of outdoor air pollution on asthma, probably through the change of an immune response, and 3) behavioral change due to exposure to violence (e.g. keeping children indoors) leads to more exposure to indoor pollutants. The suggested framework may be useful to develop health policy on asthma in high-violence communities.

Coping style and immunity in animals: making sense of individual variation

Predicting the individual vulnerability to immune mediated disease is one of the main challenges of modern biomedical research. However, the question of individual behavioral and physiological characteristics that might predict this vulnerability has been subject of research and debate for a long time. This paper will argue that animal models aimed at individual vulnerability should consider the biological function of variation in nature. An increasing number of studies show the ecological significance of variation within a species. Based on behavioral studies in several vertebrate species two coping style can be distinguished. Variation in coping style appears to play a role in the population dynamics and the evolutionary fitness of the species. Coping styles are reflected in a stable differentiation in the behavioral and physiological stress responsiveness over time and across situations. Based on the observations that the individual level of offensive aggressive behavior (i.e., the tendency to defend the home territory) is strongly related to the way animals react to various other environmental challenges, it is argued that the individual's level of offensiveness is an important indicator and component of a more trait-like behavioral and physiological response pattern (coping style) to environmental demands. The coping style of aggressive animals is principally aimed at a (pro)active prevention or manipulation of a stressor whereas the non-aggressive individuals tend to passively accept or react to it. Proactive coping is associated with high sympathetic reactivity to stressors whereas the more passive or reactive coping style generally has a higher HPA axis reactivity. In view of the immune modulating nature of these major neuroendocrine stress systems, one might expect that coping styles will be reflected in a differential vulnerability to immune mediated disease as well. Indeed, several studies have demonstrated such a relationship, indicating that the functional variation in coping style and related neuroendocrine stress reactivity, as it occurs in nature, might be a good standard for studies aimed at understanding individual vulnerability. This is in agreement with more recent views that also in humans stress reactivity may be the best predictor for the individual vulnerability to immune mediated diseases. This asks for a more fundamental and translational approach of individual disease vulnerability based on a common biological basis of individual differentiation in behavior and physiology in humans and animals.

Stress induces a switch of intracellular signaling in sensory neurons in a model of generalized pain

Stress dramatically exacerbates pain in diseases such as fibromyalgia and rheumatoid arthritis, but the underlying mechanisms are unknown. We tested the hypothesis that stress causes generalized hyperalgesia by enhancing pronociceptive effects of immune mediators. Rats exposed to nonhabituating sound stress exhibited no change in mechanical nociceptive threshold, but showed a marked increase in hyperalgesia evoked by local injections of prostaglandin E(2) or epinephrine. This enhancement, which developed more than a week after exposure to stress, required concerted action of glucocorticoids and catecholamines at receptors located in the periphery on sensory afferents. The altered response to pronociceptive mediators involved a switch in coupling of their receptors from predominantly stimulatory to inhibitory G-proteins (G(s) to G(i)), and for prostaglandin E(2), emergence of novel dependence on protein kinase C epsilon. Thus, an important mechanism in generalized pain syndromes may be stress-induced coactivation of the hypothalamo-pituitary-adrenal and sympathoadrenal axes, causing a long-lasting alteration in intracellular signaling pathways, enabling normally innocuous levels of immune mediators to produce chronic hyperalgesia.

Clostridium difficile-associated diarrhea: an emerging threat to pregnant women

OBJECTIVE

To estimate if Clostridium difficile-associated disease (CDAD) is increasing in peripartum women.

STUDY DESIGN

Peripartum CDAD was assessed through 1) passive surveillance collecting clinical and pathology data on severe cases and 2) survey among infectious disease consultants (ICDs) in the Emerging Infections Network.

RESULTS

Ten severe cases were collected; most had associated antibiotic use. Seven women were either admitted to the ICU or underwent colectomy. Three infants were stillborn, and 3 women died. The epidemic Clostridium difficile strain was found in 2 cases. Among 798 ICDs, 419 (52%) participated in the survey. Thirty-seven respondents (9%) recalled 55 cases, mostly in the postpartum period with 21 complications, mainly due to relapse.

CONCLUSION

Severe CDAD may be increasing in peripartum women. Clinicians should have a low threshold for testing, be aware of the potential for severe outcomes, and take steps to reduce both the risk of disease and resultant complications.

Endurance training modulates lymphocyte function in rats with post-MI CHF

PURPOSE

Exercise training restores innate immune system cell function in post-myocardial infarction (post-MI) rats. However, studies of the involvement of lymphocyte (Ly) in the setting of the congestive heart failure (CHF) are few. To address this issue, we investigated the function of Ly obtained from cervical lymph nodes from post-MI CHF rats submitted to treadmill running training.

METHODS

Twenty-five male Wistar rats were randomly assigned to the following groups: rats submitted to ligation of the left coronary artery, which were sedentary (MI-S, N = 7, only limited activity) or trained (MI-T, N = 6, on a treadmill (0% grade at 13-20 m.m) for 60 min.d, 5 d.wk, for 8-10 wk); or sham-operated rats, which were sedentary (sham-S, N = 6) or trained (sham-T, N = 6). The incorporation of [2-C]-thymidine by Ly cultivated in the presence of concanavalin A (Con A) and lipopolysaccharide (LPS), cytokine production by Ly cultivated in the presence of phytohemagglutinin (PHA), and plasma concentration of glutamine were assessed in all groups, 48 h after the last exercise session.

RESULTS

Proliferative capacity was increased, following incubation with Con-A in the MI groups, when compared with the sham counterparts. When incubated in the presence of PHA, MI-S produced more IL-4 (96%) than sham-S (P < 0.001). The training protocol induced a 2.2-fold increase in the production of interleukin-2 (P < 0.001) of the cells obtained from the cervical lymph nodes of MI-T, compared with MI-S.

CONCLUSION

The moderate endurance training protocol caused an increase in IL-2 production, and a trend toward the reversion of the Th1/Th2 imbalance associated with IL-4 production increased in the post-MI CHF animal model.

Cytokines and atherosclerosis: a comprehensive review of studies in mice

In the past few years, inflammation has emerged as a major driving force of atherosclerotic lesion development. It is now well-established that from early lesion to vulnerable plaque formation, numerous cellular and molecular inflammatory components participate in the disease process. The most prominent cells that invade in evolving lesions are monocyte-derived macrophages and T-lymphocytes. Both cell types produce a wide array of soluble inflammatory mediators (cytokines, chemokines) which are critically important in the initiation and perpetuation of the disease. This review summarizes the currently available information from mouse studies on the contribution of a specified group of cytokines expressed in atherosclerotic lesions, viz. interleukins (IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-10, IL-12, IL-18, IL-20) and macrophage-associated cytokines [tumour necrosis factor-α (TNF-α); macrophage migration inhibitory factor (MIF); interferon-γ (IFN-γ); colony stimulating factors G-CSF,-M-CSF,-GM-CSF) to atherogenesis. Emphasis is put on the consistency of the effects of these cytokines, i.e. inasmuch an effect depends on the experimental approach applied (overexpression/deletion, strain, gender, dietary conditions, and disease stage). An important outcome of this survey is (i) that only for a few cytokines there is sufficient consistent data allowing classifying them as typically proatherogenic (IL-1, IL-12, IL-18, MIF, IFN-γ, TNF-α, and M-CSF) or antiatherogenic (IL-10) and (ii) that some cytokines (IL-4, IL-6 and GM-CSF) can exert pro- or anti-atherogenic effects depending on the experimental conditions. This knowledge can be used for improved early detection, prevention and treatment of atherosclerosis.

Stress-induced differences in primary and secondary resistance against bacterial sepsis corresponds with diverse corticotropin releasing hormone receptor expression by pulmonary CD11c+ MHC II+ and CD11c- MHC II+ APCs

Stress responses have been associated with altered immunity and depending upon the type of stressor, can have diverse effects on disease outcomes. As the first line of defense against potential pathogens, alterations in cellular immune responses along the respiratory tract can have a significant impact on the manifestation of local and systemic disease. Utilizing a murine model of respiratory pneumonia, the current study investigated the effects of restraint stress on the induction of primary and secondary immunity along the respiratory tract, influencing host susceptibility. Female CD-1 mice were subjected to three hours of restraint stress over a period of four days followed by primary and secondary Streptococcus pneumoniae infection via intranasal route. Stress exposure led to increased retention of bacterial carriage in the lungs, enhanced polymorphonuclear cells and a preferential decrease in pulmonary CD11c(+) MHC II(+) cells resulting in delayed lethality during primary infection but significant impairment of acquired immune protection after secondary infection. We also provide evidence to support a role for lung-associated corticotropin releasing hormone regulation through peripheral CRH and diverse CRH receptor expression by MHC II(+) antigen presenting cells (APCs). We conclude that repeated restraint stress has distinct influences on immune cell populations that appear to be important in the generation of innate and adaptive immune responses along the respiratory tract with the potential to influence local and systemic protection against disease pathogenesis.

Stress hormones and immune function

Over the past 20 years we have demonstrated both in animal models and in human studies that stress increases neuroendocrine hormones, particularly glucocorticoids and catecholamines but to some extent also prolactin, growth hormone and nerve growth factor. We have also shown that stress, through the action of these stress hormones, has detrimental effects on immune function, including reduced NK cell activity, lymphocyte populations, lymphocyte proliferation, antibody production and reactivation of latent viral infections. Such effects on the immune system have severe consequences on health which include, but are not limited to, delayed wound healing, impaired responses to vaccination and development and progression of cancer. These data provide scientific evidence of the effects of stress on immune function and implications for health.

Pain and stress in a systems perspective: reciprocal neural, endocrine, and immune interactions

This paper advances a psychophysiological systems view of pain in which physical injury, or wounding, generates a complex stress response that extends beyond the nervous system and contributes to the experience of pain. Through a common chemical language comprising neurotransmitters, peptides, endocannabinoids, cytokines, and hormones, an ensemble of interdependent nervous, endocrine, and immune processes operates in concert to cope with the injury. These processes act as a single agent and comprise a supersystem. Acute pain in its multiple dimensions, and the related symptoms that commonly occur with it, are products of the supersystem. Chronic pain can develop as a result of unusual stress. Social stressors can compound the stress resulting from a wound or act alone to dysregulate the supersystem. When the supersystem suffers dysregulation, health, function, and sense of well-being suffer. Some chronic pain conditions are the product of supersystem dysregulation. Individuals vary and are vulnerable to dysregulation and dysfunction in particular organ systems due to the unique interactions of genetic, epigenetic and environmental factors, as well as the past experiences that characterize each person.

PERSPECTIVE

Acute tissue injury activates an ensemble of interdependent nervous, endocrine, and immune processes that operate in concert and comprise a supersystem. Some chronic pain conditions result from supersystem dysregulation. Individuals vary and are vulnerable to dysregulation due to the unique interactions of genetic, epigenetic, and environmental factors and past experiences that characterize each person. This perspective can potentially assist clinicians in assessing and managing chronic pain patients.

The hypothalamic-pituitary-adrenal axis in asthmatic children

Reduced responsiveness of the hypothalamic-pituitary-adrenal (HPA) axis in patients with various chronic allergic inflammatory disorders and a blunted HPA axis response of poorly controlled asthmatics before long-term treatment with inhaled corticosteroids (ICS) have been reported. It seems that pro- and anti-inflammatory cytokines might be involved in the attenuation of cortisol and adrenocorticotropic hormone (ACTH) responses to stress in these patients. Although long-term ICS treatment might produce mild adrenal suppression in some asthmatic children, improvement of adrenal function has been detected in the majority of cases. We postulate that the anti-inflammatory effects of ICS result both in asthma remission and HPA axis improvement. Adrenal suppression of some asthmatic patients on maintenance ICS seems to be a separate phenomenon, possibly constitutionally or genetically determined.

Pyrazinoindolone inhibitors of MAPKAP-K2

Optimization of pyrazinoindolone inhibitors of MAPKAP-K2 (MK2) provides a reasonable balance of cellular potency and physicochemical properties. Mechanistic studies support the inhibition of MK2 which is responsible for the sub-micromolar cellular efficacy.

Systemic antiinflammatory corticosteroid reduces mechanical pain behavior, sympathetic sprouting, and elevation of proinflammatory cytokines in a rat model of neuropathic pain

BACKGROUND

Chronic pain models are commonly defined as either nerve-injury or inflammation models, but recent work suggests inflammatory processes are important in nerve injury-induced pain.

METHODS

In the rat spinal nerve ligation model, the authors examined effects of systemic corticosteroid triamcinolone acetonide (TA) on the cytokine protein profile and sympathetic sprouting in the axotomized sensory ganglia, excitability of sensory neurons, and mechanical sensitivity.

RESULTS

By postoperative day 3, marked increases (5- to 16-fold) in monocyte chemoattractant protein-1, growth-related oncogene (GRO/KC or CXCL1), and interleukin (IL)-6 were observed, whereas IL-4 and IL-2 levels fell more than fourfold. The increased cytokines and number of sympathetic basket formations in the sensory ganglia were reduced toward normal values by TA given starting at the time of injury. Interleukin-4 and IL-2 levels were not restored by TA. Systemic TA also reduced the firing rate and incidence of bursting activity, but not the overall incidence of spontaneous activity, in large- and medium-sized neurons. Mechanical hypersensitivity on postoperative day 3 was reduced by TA, and some effect could still be observed 4 days after cessation of TA. However, starting TA at day 7 was ineffective.

CONCLUSIONS

Several components of the spinal nerve injury model are responsive to corticosteroid, suggesting inflammatory processes are important in the development of neuropathic pain. The observation that TA was effective when given starting at the time of injury suggests that steroid treatment might alter the development of chronic pain after surgical procedures that involve nerve injury, such as amputation or hernia repair.

Inhibitory effects of thyroxine on cytokine production by T cells in mice

As a sensitive factor of endocrine system, thyroxine exerts regulatory activities on a variety of cell types in immune system including T lymphocytes. Cytokines secreted by T lymphocytes are widely involved in numerous mechanisms, which are crucial for homeostasis at various statuses. Here we investigated the effects of thyroxine on the cytokine production of T lymphocytes in vivo and in vitro, using BALB/c mice with thyroxine treatment. We examined the IFN-gamma, IL-2, IL-4 and IL-10 of T-cell type cytokines transcriptions and the proportions of IFN-gamma, IL-4 and IL-10-secreting CD4(+)/CD8(+) T cells. The results showed that the administration of high-level thyroxine induced weakly expression of T-cell type cytokine in transcriptional level together with impaired responsibility to mitogen (Con A) stimulation. Along with the severe suppression on T-cell type cytokine transcription, the proportions of IFN-gamma, IL-4 and IL-10-producing T lymphocytes were markedly attenuated and the productions of serum IFN-gamma and IL-10 were significantly decreased synchronously. The repressive effects of thyroxine on T-cell type cytokine were seen both in mRNA and protein level. The results suggested that T lymphocytes under normal condition appear to be sensitive to suppression of high-level thyroxine administration.

Cardiovascular disease risk factors in adolescents: do negative emotions and hypothalamic-pituitary-adrenal axis function play a role?

PURPOSE OF REVIEW

Negative emotions such as depression and hostility/anger are important risk factors for cardiovascular disease in adults, but are often neglected in treatment or prevention programs. Adolescence is a stage of life when negative emotions often first become problematic and is also a time when the pathogenesis of cardiovascular disease appears to accelerate. The literature on negative emotions and cardiovascular disease risk factors in adolescents is reviewed here.

RECENT FINDINGS

Research indicates that negative emotions are associated with cardiovascular disease risk factors in adolescence. Negative emotions are also associated with several types of hypothalamic-pituitary-adrenal axis dysregulation. Such dysregulation appears to have a facilitatory effect on cardiovascular disease development and progression in adults. Thus, it is possible that negative emotions in adolescents may be risk factors for the development of cardiovascular disease via dysregulation of the hypothalamic-pituitary-adrenal axis. Although this hypothesis has not been directly tested, some studies indirectly support the hypothesis.

SUMMARY

Negative emotions are associated with cardiovascular disease risk factors in adolescents; it is possible that hypothalamic-pituitary-adrenal axis dysregulation is an important mechanism. This hypothesis merits further research. If the hypothesis is valid, it has significant implications for early prevention of cardiovascular disease.

Osteopontin regulates hindlimb-unloading-induced lymphoid organ atrophy and weight loss by modulating corticosteroid production

Osteopontin (OPN), a multifunctional secreted phosphoglycoprotein, plays diverse roles in bone biology, immune regulation, cell survival, inflammation, and cancer metastasis. Here we show its role in determining lymphocyte homeostasis and body mass in response to hindlimb unloading (HU), a model for evaluating effects of weightlessness on the musculoskeletal and other physiological systems. Using this stress model, we compared OPN(-/-) mice with OPN(+/+) mice subjected to HU for 3 days. Whereas OPN(+/+) mice suffered a marked reduction of body weight and significant spleen and thymus atrophy, OPN(-/-) mice exhibited minor weight loss and much less spleen and thymus atrophy. The HU-induced lymphoid organ atrophy was the result of dramatically diminished numbers, respectively, of T and B cells in the spleen and CD4(+)CD8(+) double-positive cells in the thymus of OPN(+/+) mice. Increased levels of corticosterone, which modulates lymphocyte activation responses and apoptosis during stress, were found only in OPN(+/+) mice. Apoptotic cell death was evident in the spleen and thymus of OPN(+/+) mice subjected to HU but not in OPN(-/-)mice. Importantly, lymphocytes from both OPN(+/+) and OPN(-/-) mice were equally sensitive to corticosteroid-induced apoptosis. These results reveal that OPN is required for enhanced corticosterone production, immune organ atrophy, and weight loss in mice subjected to HU.

T-helper 1/T-helper 2 cytokine imbalance and clinical phenotypes of acute-phase major depression

Several studies have discussed the relationships between T-helper 1 (Th1) or Th2 cytokines and major depression. The aim of the present study was to investigate the relationships between Th1/Th2 cytokine balance and clinical phenotypes of acute-phase major depression. A total of 82 subjects including 42 patients with major depressive disorder and 40 healthy controls were recruited. Serum cytokine levels of interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha) and IL-10 were examined. Using ancova with age and body mass index (BMI) adjustments, there were no significant differences in serum IL-1beta, TNF-alpha, and IL-10 levels between patients with major depressive disorder and healthy controls. However, using ANCOVA with BMI adjustment only, the results showed that patients with major depressive disorder had significantly higher TNF-alpha levels than control subjects. In addition, using ANCOVA with age and BMI adjustments, significantly higher serum IL-1beta level and IL-1beta/IL-10 ratio were noted in patients with melancholic features than patients with non-melancholic features. However, there were no significant differences in serum IL-1beta, TNF-alpha and IL-10 levels between patients with and without suicide attempt. In conclusion, serum TNF-alpha, IL-1beta level and IL-1beta/IL-10 ratio might play an important role in the psychopathology of acute-phase major depressive disorder.

T helper type 1 cytokines and keratinocyte growth factor play a critical role in pseudoepitheliomatous hyperplasia initiation during cutaneous leishmaniasis

Pseudoepitheliomatous hyperplasia (PEH) is an exuberant proliferation of the epidermis. The underlying mechanism(s) that lead to PEH have not been completely elucidated. Here, we characterize PEH during the healing stages of cutaneous leishmanial ulcers in mice. During experimental cutaneous leishmaniasis (CL) C57BL/6 mice produce PEH, and BALB/c do not. A series of immunohistochemical and immunological studies were performed to identify the secretory products of PEH regulation. We observed that the distribution of TNF-alpha and IFN-gamma under PEH had a stripe-like diffuse pattern and localized in the upper part of the papillary dermis directly under the proliferating epidermis. Macrophages were identified as the major source of TNF-alpha (56.3%). The importance of IFN-gamma and TNF-alpha in PEH development was proven by the initiation of PEH after three intralesional injections of TNF-alpha and IFN-gamma every three days in infected BALB/c mice. In C57BL/6 mice, keratinocyte growth factor (KGF) expressing cells were found immediately under the basal membrane of the hyperplastic epidermis in comparison with sporadic KGF positive cells deep in the dermis of BALB/c mice. Quantitative RT-PCR analysis demonstrated increased KGF and KGF receptor expression in uninfected C57BL/6 mice as compared to BALB/c mice. These data indicate that Th1 cytokines and KGF play a critical role in PEH initiation during CL.

In hemocytes from Mytilus galloprovincialis Lmk., treatment with corticotropin or growth factors conditions catecholamine release

The cells in charge of the innate immune response in the sea mussel Mytilus galloprovincialis Lmk. are the hemocytes, which have the capacity to release catecholamines when subjected to stressing conditions. Hemocytes were kept in culture before stimulation. That is, their behaviour was not studied immediately after extraction from the mollusc, as happens in most studies. This avoids the interference and variability caused by the conditions in which mussels may be when collected. This work describes the great variability found in the pattern of catecholamine release when the hemocytes are stimulated with either corticotropins or growth factors. Dopamine, adrenaline and noradrenaline release differs with each of the inducers assayed, with stimulation time and with the season of hemocyte collection. One of the results presented is particularly remarkable; such is the great amount of adrenaline and noradrenaline released to the medium when the hemocytes obtained in summer are stimulated with transforming growth factor-beta1 (TGF-beta1) for 60 min.

Neurohormonal-cytokine interactions: implications for inflammation, common human diseases and well-being

The neuroendocrine system affects the immune system through the neuroendocrine humoral outflow via the pituitary, and through direct neuronal influences via the sympathetic, parasympathetic (cholinergic) and peptidergic/sensory innervation of peripheral tissues. Circulating hormones or locally released neurotransmitters and neuropeptides regulate major immune functions, such as antigen presentation, antibody production, lymphocyte activity, proliferation and traffic, and the secretion of cytokines including the selection of T helper (Th)1 or Th2 cytokine responses. During inflammation, the activation of the stress system, through induction of a Th2 shift protects the organism from systemic "overshooting" with Th1/pro-inflammatory cytokines. Under certain conditions, however, stress hormones, substance P, ATP and the activation of the corticotropin-releasing hormone/substance P-histamine axis may actually facilitate inflammation, through induction of interleukin (IL)-1, IL-6, IL-8, IL-18, tumor necrosis factor (TNF)-alpha and CRP production. Thus, a dysfunctional neuroendocrine-immune interface associated with abnormalities of the 'systemic anti-inflammatory feedback' and/or 'hyperactivity' of the local pro-inflammatory factors may play a role in the pathogenesis of atopic/allergic and autoimmune diseases, obesity, depression and atherosclerosis. Better understanding of the neuroendocrine control of inflammation may provide critical insights into mechanisms underlying a variety of common human immune-related diseases.

Effect of repeated restraint stress on the levels of intestinal IgA in mice

The effects of restraint stress on the intestinal humoral immune system, particularly those about intestinal IgA production, have not been explored in detail. Thus, the purpose of this study was to assess the effect of restraint stress on the production and secretion of intestinal IgA as well as on the number of IgA+ cells in the intestinal lamina propria. The involvement of glucocorticoids and catecholamines were also evaluated. Mice were exposed to 1 or 4 h restraint stress for 4 d. The intestinal IgA concentration was quantified by ELISA and the number of IgA containing cells in the lamina propria was determined by immunohistochemistry. The effects of restraint were also analyzed in mice submitted to different procedures: adrenalectomy, chemical sympathectomy, treatment with a glucocorticoid antagonist (RU486), dexamethasone and epinephrine. The main findings were that (1) chronic restraint-stress reduced the intestinal IgA concentration without changing the number of IgA+ cells in lamina propria; (2) adrenalectomy restored the production of IgA in stressed mice; (3) RU486 and chemical sympathectomy partially blocked the decrease in intestinal IgA in stressed mice; and (4) pharmacological doses of dexamethasone and epinephrine significantly reduced the intestinal IgA concentration and the number of IgA+ cells. The restraint stress probably reduced the intestinal IgA concentration through the effects of glucocorticoids and catecholamines.

Immune system changes during simulated planetary exploration on Devon Island, high arctic

Background

Dysregulation of the immune system has been shown to occur during spaceflight, although the detailed nature of the phenomenon and the clinical risks for exploration class missions have yet to be established. Also, the growing clinical significance of immune system evaluation combined with epidemic infectious disease rates in third world countries provides a strong rationale for the development of field-compatible clinical immunology techniques and equipment. In July 2002 NASA performed a comprehensive immune assessment on field team members participating in the Haughton-Mars Project (HMP) on Devon Island in the high Canadian Arctic. The purpose of the study was to evaluate the effect of mission-associated stressors on the human immune system. To perform the study, the development of techniques for processing immune samples in remote field locations was required. Ten HMP-2002 participants volunteered for the study. A field protocol was developed at NASA-JSC for performing sample collection, blood staining/processing for immunophenotype analysis, whole-blood mitogenic culture for functional assessments and cell-sample preservation on-location at Devon Island. Specific assays included peripheral leukocyte distribution; constitutively activated T cells, intracellular cytokine profiles, plasma cortisol and EBV viral antibody levels. Study timepoints were 30 days prior to mission start, mid-mission and 60 days after mission completion.

Results

The protocol developed for immune sample processing in remote field locations functioned properly. Samples were processed on Devon Island, and stabilized for subsequent analysis at the Johnson Space Center in Houston. The data indicated that some phenotype, immune function and stress hormone changes occurred in the HMP field participants that were largely distinct from pre-mission baseline and post-mission recovery data. These immune changes appear similar to those observed in astronauts following spaceflight.

Conclusion

The immune system changes described during the HMP field deployment validate the use of the HMP as a ground-based spaceflight/planetary exploration analog for some aspects of human physiology. The sample processing protocol developed for this study may have applications for immune studies in remote terrestrial field locations. Elements of this protocol could possibly be adapted for future in-flight immunology studies conducted during space missions.

Adeno-associated viral vector-mediated interleukin-10 prolongs allograft survival in a rat kidney transplantation model

Interleukin-10 (IL-10) is a pleiotropic cytokine that plays a pivotal role in the regulation of immune responses. Hence, we evaluated the effects of a recombinant adeno-associated viral vector 1 (rAAV1) encoding rat IL-10 (rAAV1-IL-10) in a rat model of kidney allograft rejection. Dark Agouti rat kidneys were transplanted into Wistar-Furth (WF) rats 8 weeks following a single intramuscular administration of either rAAV1-IL-10 or rAAV1-green fluorescence protein (GFP). Isografts (WF-WF) served as an additional experimental control. Both allograft and isograft recipients received daily cyclosporine (10 mg/kg) for 14 days after transplantation. Serum IL-10 levels increased at 8, 12 and 16 weeks following vector administration in rAAV1-IL-10-treated animals, but not in rAAV1-GFP and isograft groups. rAAV1-IL-10 treatment resulted in lower BUN and creatinine levels (p<0.001), as well as increased allograft survival rates from 22% to 90%. Allograft histological abnormalities were significantly attenuated in the rAAV1-IL-10-treated rats compared with those of rAAV1-GFP controls. Serum levels of proinflammatory cytokines such as growth-related oncogene were also significantly higher in the rAAV1-GFP group than in the rAAV1-IL-10 group. These data suggest delivery of IL-10 using a rAAV1 vector improves renal function and prolongs graft survival in a rat model of kidney transplant rejection.

Inflammatory cytokines in relation to adrenal response following total hip replacement

Our objective was to investigate the initiation and course of pro- and anti-inflammatory cytokines in early inflammatory response and to elucidate the cytokine system in relation to the adrenal response caused by stress. Seven blood samples were collected, pre- and postoperatively (0-72 h) after total hip replacement (THR) due to osteoarthritis. The following cytokines were measured using Cytometric Bead Array: interleukin-1beta (IL-1beta), IL-6, tumour necrosis factor-alpha, IL-8, IL-12 and IL-10 (B&D). Thirteen patients took part in the study (67 +/- 9 years). C-reactive protein increased from <6 to over 200 mg/l on the second post-op day. The concentration of IL-6 increased 10-fold just 3 h post-op (4-47 pg/ml) and reached its maximum value 6 h post-op (77 pg/ml; Wilcoxon test P < 0.01) Repeated measurements were also significant (Friedman P < 0.05). The concentration of IL-8 doubled the day of surgery but did not reach a significant level (Friedman test =0.069). None of the other cytokines showed any significant changes. The diurnal cortisol rhythm was interrupted after the surgery and there was a significant correlation between the cortisol secretion and IL-6 response. This study demonstrates an isolated elevation in IL-6 levels with only a minor elevation in IL-8 following THR. This pro-inflammatory response seemed to decline without activation of anti-inflammatory cytokines (IL-10), but cortisol seemed to play a complicated role in halting the acute inflammatory response.

Cytokines and the immune–neuroendocrine network: What did we learn from infection and autoimmunity?

The initial view of the neuroendocrine-immune communication as the brake of immune activation is changing. Recent evidence suggests that the optimization of the body's overall response to infection could be actually the role of the immune-endocrine network. In gradually more complex organisms, the multiplicity of host-pathogen interfaces forced the development of efficient and protective responses. Molecules such as cytokines and Toll-like receptors (TLRs) are distributed both in the periphery and in the brain to participate in a coordinated adaptive function. When sustained release of inflammatory mediators occurs, as in autoimmune diseases, undesirable pathological consequences become evident with different manifestations and outcomes. Clearly, organisms are not well adapted to that disregulated condition yet, suggesting that additional partners within neuroendocrine-immune interactions might emerge from the evolutionary road.