Stress-induced augmentation of immune function--the role of stress hormones, leukocyte trafficking, and cytokines

Delayed-type hypersensitivity (DTH) reactions represent cell-mediated immune responses that exert important immunoprotective (resistance to viruses, bacteria, and fungi) or immunopathological (allergic or autoimmune hypersensitivity) effects. We initially utilized the skin DTH response as an experimental in vivo model to study neuro-endocrine-immune interactions in rodents. We hypothesized that just as an acute stress response prepares the cardiovascular and musculoskeletal systems for fight or flight, it may also prepare the immune system for challenges which may be imposed by a stressor. The skin DTH model allowed us to examine the effects of stress at the time of primary and secondary exposure to antigen. Studies showed that acute (2h) stress experienced before primary or secondary antigen exposure induces a significant enhancement of skin DTH. Importantly, this enhancement involved innate as well as adaptive immune mechanisms. Adrenalectomy eliminated the stress-induced enhancement of DTH. Acute administration of physiological (stress) concentrations of corticosterone and/or epinephrine to adrenalectomized animals enhanced skin DTH. Compared with controls, DTH sites from acutely stressed or hormone-injected animals showed significantly greater erythema and induration, numbers of infiltrating leukocytes, and levels of cytokine gene expression. In contrast to acute stress, chronic stress was immunosuppressive. Chronic exposure to corticosterone, or acute exposure to dexamethasone significantly suppressed skin DTH. These results suggest that during acute stress, endogenous stress hormones enhance skin immunity by increasing leukocyte trafficking and cytokine gene expression at the site of antigen entry. While these results are discussed from a mechanistic and clinical relevance perspective, it is acknowledged that much work remains to be done to elucidate the precise mechanisms mediating these bi-directional effects of stress and stress hormones and their clinical ramifications.

Stress hormones and the immunological responses to heat and exercise

This review focuses on the response of "stress" hormones to heat, exercise (single or repeated bouts), and combinations of these stimuli, with particular reference to their impact upon immune function. Very hot conditions induce a typical stress response, with secretion of catecholamines and cortisol. The catecholamines induce a demargination of leukocytes, and cortisol subsequently causes cells to migrate to lymphoid tissue. Sustained exercise, even in a thermally comfortable environment, induces a larger hormonal response than moderate thermal stress. With moderate exercise, increases in leukocyte numbers are related mainly to plasma norepinephrine concentrations, but with more intense exercise epinephrine concentrations assume a major importance. As exercise continues, plasma cortisol levels also rise, inducing an influx of neutrophils from bone marrow and an efflux of other leukocyte subsets. A combination of exercise and heat stress augments both hormonal and leukocyte responses. But these changes seem to be reversed if temperatures are clamped by exercising in cold water. If a second bout of exercise is performed with an inter-test interval of 30-45 min, neither hormone concentrations nor immune responses show any great cumulative effect under temperate conditions. However, in a hot environment the second exercise bout induces a larger and more persistent neutrophilia. Training influences these various responses mainly by decreasing the stress imposed when exercising at a given absolute work-rate.

Adrenaline for the treatment of anaphylaxis: cochrane systematic review

BACKGROUND

Anaphylaxis is a serious allergic reaction that is rapid in onset and may cause death. Adrenaline is recommended as the initial treatment of choice for anaphylaxis.

OBJECTIVES

To assess the benefits and harms of adrenaline in the treatment of anaphylaxis.

METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 1), MEDLINE (1966 to March 2007), EMBASE (1966 to March 2007), CINAHL (1982 to March 2007), BIOSIS (to March 2007), ISI Web of Knowledge (to March 2007) and LILACS (to March 2007). We also searched websites listing ongoing trials: http://www.clinicaltrials.gov/, http://www.controlledtrials.com and http://www.actr.org.au/ and contacted pharmaceutical companies and international experts in anaphylaxis in an attempt to locate unpublished material. Randomized and quasi-randomized controlled trials comparing adrenaline with no intervention, placebo or other adrenergic agonists were eligible for inclusion. Two authors independently assessed articles for inclusion.

RESULTS

We found no studies that satisfied the inclusion criteria.

CONCLUSIONS

On the basis of this review, we are unable to make any new recommendations on the use of adrenaline for the treatment of anaphylaxis. In the absence of appropriate trials, we recommend, albeit on the basis of less than optimal evidence, that adrenaline administration by intramuscular injection should still be regarded as first-line treatment for the management of anaphylaxis.

Cold-stress induced the modulation of catecholamines, cortisol, immunoglobulin M, and leukocyte phagocytosis in tilapia

The concentrations of norepinephrine in hypothalamus and norepinephrine and epinephrine in head kidney were significantly decreased in treated tilapia (Oreochromis aureus) during the time course of cold exposure (12 degrees) as compared to the control (25 degrees). The elevation of norepinephrine and epinephrine in plasma was detected earlier than that of cortisol in cold-treated tilapia. Phagocytic activity of leukocytes and the levels of plasma immunoglobulin M (IgM) were depressed in cold-treated tilapia as compared to the control group. Handling stress in the control (25 degrees) also resulted in increased plasma cortisol and decreased plasma IgM levels but not phagocytic activity. In vitro cortisol suppressed leukocyte phagocytosis in a dose (10(-12) to 10(-4) M)-dependent manner. Adrenergic agonist (phenylephrine and isoproterenol) had a significant suppression of phagocytosis only at the highest dose (10(-4) M). No effect on phagocytosis was detected in the treatment with norepinephrine and epinephrine. A combination of cortisol and isoproterenol (0.1 mM) had an additive effect in the suppression of phagocytosis. It is concluded that the cold stress modulated the changes of catecholamines and cortisol and further depressed phagocytic activity and antibody levels in tilapia. Cortisol could play a main and important role in the down-regulation of phagocytic activity. Adrenergic agonists also could interact with cortisol to further suppress immunity in tilapia.

Immunohistochemical and biochemical study on the development of the noradrenaline- and adrenaline-storing cells of the adrenal medulla of the rat

The pre- and postnatal development of the adrenal medulla was examined in the rat by immunohistochemistry and by assay of catecholamines. Immunohistochemistry involved the use of antibodies to noradrenaline (NA), adrenaline (A) and the biosynthesizing enzymes dopamine beta-hydroxylase (DBH) and phenylethanolamine N-methyltransferase (PNMT). Adrenal glands were obtained from animals from the 16th day of gestation to the 7th postnatal day at daily intervals, and at the 14th postnatal day, and from adult rats. Tissues were fixed in ice-cold, 4% paraformaldehyde, buffered at pH 7.3. Cryostat sections (7 microns) were stained with the indirect immunofluorescence technique. Adrenals from the same developmental stages were assayed for the presence of DA (dopamine), NA and A by ion-pair reversed-phase liquid chromatography with electrochemical detection. In adult adrenals the majority of the medullary cells (approximately 80%) were highly immunoreactive to A and moderately immunoreactive to NA. They also showed immunoreactivity to both DBH and PNMT, i.e., they are synthesizing and storing A. The remaining cell clusters were only stained by antibodies to DBH and NA (NA-synthesizing and -storing cells). These findings correlate well with the relative concentrations of A and NA as determined by assay. Three developmental phases could be distinguished. In the first phase, the 16th and 17th prenatal day, medullary cells were only immunoreactive to DBH and NA, and only very small amounts of A as compared to NA were found. During the second period, from the 18th prenatal day to 2 or 3 days after birth, all medullary cells were immunoreactive to DBH, NA, PNMT and A, and during this phase the adrenaline concentration increased daily and became the predominant amine on the 20th day of gestation. Adrenaline represented 75% of total catecholamine on the 1st to 3rd day after birth. The third phase started at the 2nd or 3rd postnatal day and was characterized by the presence of an increasing number of medullary cells solely immunoreactive to DBH and NA, hence synthesizing and storing NA. The remaining cells were immunoreactive to DBH, NA, PNMT and A. Postnatally, the relative concentration of A continued to rise reaching 79% by the 4th postnatal day. These results indicate that initially the adrenal medullary cells are synthesizing and storing almost exclusively NA.(ABSTRACT TRUNCATED AT 400 WORDS)

Adrenergic modulation of survival and cellular immune functions during polymicrobial sepsis

OBJECTIVE

An immunomodulatory effect of epinephrine has been reported that is supposed to be mediated via beta-adrenergic receptors. The effect of epinephrine and/or beta-adrenergic blockade on cellular immune functions during systemic inflammation has not yet been investigated.

METHODS

Male NMRI mice were treated with either an infusion of epinephrine (0.05 mg/kg/h i.p.), administration of the nonselective beta-adrenoceptor antagonist propranolol (0.5 mg/kg s.c.), or a combination of epinephrine and propranolol after induction of a polymicrobial sepsis by cecal ligation and puncture. Forty-eight hours thereafter survival and cellular immune functions (splenocyte proliferation, splenocyte apoptosis and cytokine release, distribution of leukocyte subsets) were determined.

RESULTS

Infusion of epinephrine did not affect lethality of septic mice but induced alterations of splenocyte apoptosis, splenocyte proliferation and IL-2 release and was associated with profound changes of circulating immune cell subpopulations. Treatment with propranolol augmented the epinephrine-induced increase of splenocyte apoptosis, did not affect the decrease of splenocyte proliferation and IL-2 release, augmented the release of IL-6 and antagonized the mobilization of natural killer cells observed in epinephrine-treated animals. Furthermore, these immunologic alterations were accompanied by a significant increase of sepsis-induced mortality. Coadministration of propranolol and epinephrine augmented the propranolol-induced changes of splenocyte apoptosis and IL-6 release and was associated with the highest mortality of septic mice.

CONCLUSION

Epinephrine infusion modulated cellular immune functions during systemic inflammation without an impact on survival. A pharmacologic beta-adrenergic blockade partly augmented the epinephrine-induced immune alterations and was associated with a pronounced increase of mortality. This effect was further augmented by a combination of epinephrine infusion and beta-adrenergic blockade. These data indicate that adrenergic mechanisms modulate cellular immune functions and survival during sepsis, with these effects being mediated via alpha- and beta-adrenergic pathways.

Temporal pattern and effect of sex on lipopolysaccharide-induced stress hormone and cytokine response in pigs

The temporal pattern and sex effect of immune and stress hormone responses to a lipopolysaccharide (LPS) challenge were assessed using a pig model. Secretion of the pro-inflammatory cytokines tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and IL-6 increased in a time-dependent manner following LPS infusion. There was also a time-dependent increase in secretion of the stress-related hormones cortisol, epinephrine (E), and norepinephrine (NE) following LPS, with peak concentrations attained within 30 min. The magnitude of the TNF-alpha and IL-1beta responses were both positively associated (P < 0.05) with the magnitude of cortisol response following LPS, whereas serum IL-1beta and IL-6 were positively correlated with the magnitude of E and NE responses following LPS. Acute-phase protein production was also time-dependently increased following LPS. The concentration of immune cells in circulation was decreased (P < 0.05) at 5.5h post-LPS and negatively correlated with pro-inflammatory cytokine production. By 24h post-LPS, immune cell counts increased (P < 0.05) and were positively associated with both pro-inflammatory cytokine and stress hormone production. The amplitude of pro-inflammatory cytokine response following LPS was affected (P < 0.05) by sex classification; however, the magnitude of elevated cytokine concentrations was not. The magnitude of the NE response, but not of the E and cortisol responses, to LPS was influenced by sex (P < 0.05). Similar to the pro-inflammatory cytokines, the magnitude of exposure to the stress hormones following LPS was not influenced by sex. The production of serum amyloid A (SAA) was influenced by sex, with barrows producing more SAA than gilts at 24h post-LPS (P < 0.05). Collectively, these results demonstrate sex-specific, concomitant temporal changes in innate immune- and stress-related hormones.

Inter-kingdom signaling between gut microbiota and their host

The crosstalk between prokaryotic bacteria and eukaryotic gut epithelial cells has opened a new field for research. Quorum sensing system (QS) molecules employed by gut microbiota may play an essential role in host-microbial symbioses of the gut. Recent studies on the gut microbiome will unveil evolved mechanisms of the host to affect bacterial QS and shape bacterial composition. Bacterial autoinducers (AIs) could talk to the host's gut by eliciting proinflammatory effects and modulating the activities of T lymphocyte, macrophage, dendritic cells, and neutrophils. In addition, the gut mucosa could interfere with bacterial AIs by degrading them or secreting AI mimics. Moreover, bacterial AIs and gut hormones epinephrine and noradrenaline may be interchangeable in the crosstalk between the microbiota and human gut. Therefore, inter-kingdom signaling between gut microbiota and host may provide a novel target in the management of gut microbiota-related conditions or diseases in the future.

Overnight changes of immune parameters and catecholamines are associated with mood and stress

OBJECTIVES

To test the hypothesis that a nocturnal decrease of secretion of inflammation markers and catecholamines would be associated with mood and stress variables even after controlling for objective sleep variables.

METHODS

A total of 130 healthy volunteers participated in this study, spending 2 nights in the Gillin Laboratory of Sleep and Chronobiology at the University of California, San Diego, General Clinical Research Center. Blood samples were obtained before sleep (10:30 PM) and after awakening (6:30 AM) on the first day, and these samples were assayed for inflammatory biomarkers and catecholamines. On the second night, polysomnographic records were scored for objective sleep variables, e.g., total sleep time and wake after sleep onset. Self-rating scales for mood, stress, depression, and daily hassles were administered the second day.

RESULTS

The nocturnal decrease in interleukin-6 was smaller in people who reported more negative mood or fatigue and greater in those who reported more uplift events (e.g., with Profile of Mood States fatigue r(p) = -.25 to -.30). People with high stress or high depression levels had smaller nocturnal decreases of epinephrine. That relationship was even stronger when partial correlations were used to control for morning level and sleep variables. The associations between nocturnal changes of C-reactive protein, soluble tumor necrosis factor-receptor I, and norepinephrine with psychological states were nonremarkable.

CONCLUSIONS

The analyses of nocturnal change scores (difference scores) add substantial information compared with the traditional analyses of morning levels of immune variables and catecholamines alone. Subjective well-being is significantly associated with a greater nocturnal decrease of interleukin-6 and epinephrine. More research on nocturnal adaptation processes is warranted.

The development of enzyme-linked immunosorbent assays (ELISA) for the catecholamines adrenalin and noradrenalin

Monoclonal antibodies have been raised against adrenalin and noradrenalin and used as the basis of enzyme-linked immunosorbent assays (ELISA) to detect and estimate the concentrations of these catecholamines. Inhibition assays are described, with sensitive quantification in the range from 1 mg/ml to 100 pg/ml. Cross-reactivity assays reveal that neither assay is subject to interference by catecholamine metabolites at concentrations less than 100 ng/ml and 1 micrograms/ml respectively. Isolation and quantification of both catecholamines from clinical samples is discussed and the potential application of these ELISAs in a clinical setting is proposed.

Involvement of catecholamines in recall of the conditioned NK cell response

The primary goal of the study was to identify the types of catecholamines and the associated receptors which might be involved in the recall of the conditioned NK cell response. Specific catecholamine receptor antagonists were selected to block the conditioned NK cell response at the recall step. The regional contents of dopamine (DA), norepinephrine (NE), and epinephrine were determined in the brain of the conditioned animals by using the high performance liquid chromatography with electrochemical detection (HPLC/ED). Results showed that pre-disruption of the central alpha1-, alpha2-, beta1-, beta2-, D1-, or D2-receptors at the conditioned recall stage, interrupted the conditioned enhancement in NK cell activity. The NE contents at the cerebellum, and DA contents at the striatum and hippocampus, were significantly higher in the brain of the conditioned animals when compared to that of the control animals. These information indicated the possible roles of the central noradrenergic and dopaminergic systems in regulating the recall of the conditioned NK cell response.

Examination of neutrophil function in a rat model of decreased host resistance following burn trauma

The high incidence of serious opportunistic infection following human burn injury has been well documented. Investigations of the mechanisms of this acquired susceptibility have demonstrated several defects in phagocytic defenses. An established rat burn infection model was modified for study of neutrophil function in animals with a 60% burn injury. These 350-g rats received a 35-ml saline resuscitation, and when not further stressed, 80% of the animals survived to healing. Burned animals were found to have decreased inflammatory responses to intraperitoneal injections of heat-killed Pseudomonas aeruginosa, Staphylococcus aureus, and sterile sodium caseinate. These reductions could not be explained by neutropenia. Prior immunization with heat-killed Pseudomonas did not improve the inflammatory response to homologous organisms injected intraperitoneally, but levamisole treatment did improve the inflammatory response. Epinephrine injection (intravenous) showed that burned animals have a markedly reduced proportion of marginated neutrophils but an increase in total peripheral neutrophil counts. The stress hormones corticosterone and catecholamines were elevated during times of decreased inflammatory responsiveness; additionally, neutrophils from burned animals had decreased adherence to nylon fiber. Serum from burned animals decreased in vitro adherence and chemotaxis of purified normal rat neutrophils.

Epinephrine-binding plasma-membrane antigens in rat liver

Detergent extracts of isolated rat liver plasma membranes were analysed in two-dimensional immunoelectrophoresis against antiserum to plasma membranes. Enzyme staining of the immunoprecipitates revealed the presence of about ten antigens with nucleoside di- and triphosphatase activity. Most of these were earlier shown also to be NADH-neotetrazolium reductase active. In addition, two of these antigens exhibited L-leucyl-beta-naphthylamidase activity. As judged from autoradiography these plasma membrane antigens earlier characterized as multienzyme complexes bound [14C]epinephrine, and the same antigens were labelled regardless of whether membranes or membrane extracts were incubated with the radioactive hormone. The specificity of this binding was established in displacement experiments with unlabelled hormones or their analogues. Another hormone-binding antigen, also identified in the plasma membrane extract did not exhibit any known enzyme activity while three antigens with different enzyme activities had no epinephrine-binding capacity. [14C]Epinephrine-labelled plasma membrane extracts were chromatographed on Sepharose 4B and the fractions obtained were analysed in two-dimensional immunoelectrophoresis combined with autoradiography. Nucleoside di- and triphosphatases of high molecular weights (5000000) were associated with L-leucyl-beta-naphthylamidase activity, while no such associations were detected in a lower molecular weight region (70000). Further immunological studies on the various fractionated antigens provided evidence that at least two of them occurred in both low and high molecular weight fractions. Hormone-binding membrane components in varying concentrations were found throughout the eluted extract.

Biochemical resistance to development of morphine-dependence in rats: biogenic amines, its receptors and antibodies

The level of norepinephrine (NE), epinephrine (E) and dopamine (DA) in hypothalamus and blood plasma along with antibodies to NE, DA and serotonin (5-HT) and characteristics of alpha 1-, alpha 2-adrenergic, D2-dopaminergic and S2-serotoninergic receptors in synaptic brain membranes were studied in two groups of rats predisposed or resistant to the formation of physical morphine dependence. The resistant animals were characterized by a significant elevation of DA levels in blood plasma, elevation of antibodies to NE, and by higher concentration of alpha 2-adrenergic receptors in the brain cortex and of D2-receptors in striatum. The affinity of D2-receptors to dopamine in resistant rats also was higher than in predisposed animals. The other parameters studied did not differ significantly between the two groups. These findings suggest that the increased activity of DA and NE neurotransmitter systems can be a cause for the genetic resistance of some individuals among Wistar rats to the formation of physical dependence on morphine.

[Comparative study on the effect of antiatherosclerotic diet enriched with polyunsaturated omega-3 fatty acids of plant and animal origin on the level of natural antibodies against catecholamines in patients with cardiovascular diseases]

The levels of natural antibodies against catecholamines in 138 patients with cardiovascular diseases was studied and the comparative analysis of influence of antiatherosclerotic diets with different origin of PUFA omega-3 on dynamic of these parameters was made. For the first time discovered universal action of diets with PUFA omega-3 vegetable and animal origin on parameters of humoral immunity: in case of primary excess of norm of the contents of natural antibodies to adrenaline, noradrenaline and dopamine as a result of treatment these parameters were reduced or did not change; and at is primary a low their level--parameters increased in most cases. The greatest immunocorrection effect was rendered by diet, enriched PUFA omega-3 of freshwater fishes fat.

[Liver mitochondria in antigenic stress in rats]

The penomenon of reciprocal regulation of succinate dehidrogenase activity in rat liver mitochondria was elicited in antigenic strain induced by the administration of activated lymphocytes from animals with allotransplated heart. Two coupled but opposite changes (simultaneous activation and inhibition) in succinate depended ATP synthesis and calcium transport occur. The inhibition was correlated with the activation of synthetic processes in hepatocytes. Similar changes were provoked by epinephrine (either administered i.p. or released endogenously under immobilization stress and in myocardium infarction) as well as in patients with stomach tumor. The physiological significance of the reciprocal regulation of succinate dehydrogenase is discussed.

[The effect of catecholamine and serotonin antibodies on pain sensitivity and the development of morphine tolerance in experimental drug addiction]

The effect of antibodies to catecholamine and serotonin on the thermal pain sensitivity and tolerance to morphine was studied in rats immunized by protein-conjugated neurotransmitters before chronic drug intoxication. The antibodies to catecholamine have been found to affect bifunctionally on the nociception bifunctionally: either accelerating or delaying the pain reaction to thermal irritation. The antibodies to serotonin were ineffective as modulators both of the pain sensitivity and tolerance to morphine development. In contrast, the antibodies to catecholamine suppressed the expression of tolerance to chronic morphine. Serotonin antibodies virtually produced no effects on pain sensitivity and the development of morphine tolerance.

[Immunoenzyme analysis of natural antibodies to endogenous bioregulators in patients with systemic lupus erythematosus]

Serum levels of autoantibodies to endogenous bioregulators (prostaglandin F2 alpha, angiotensin II, epinephrine, bovine serum albumin, dinitrophenol) were measured in patients with systemic and integumental lupus erythematosus and donors and the diagnostic significance of deviations of these levels from the norm was evaluated. A total of 75 patients with lupus erythematosus aged 19-54 years with disease lasting for 0.5 to 18 months were examined. Significant differences between patients and donors were observed as regards virtually all parameters except IgG to angiotensin II.

[Case report : Severe anaphylactic shock followed by positive skin-prick-test to multiple vasoconstrictors]

A 71-year-old woman was scheduled for revision of total hip replacement under general anesthesia. Twenty minutes before entering the operating room, slight urticaria was caused by drop infusion of cefotiam. It was stopped immediately and the patient entered the operating room without any symptoms. Anesthesia was induced and maintained with sevoflurane and remifentanil. After 3 hours, systolic arterial pressure (SAS) dropped to 80 mmHg. Injecting of ephedrine 8 mg was not effective, and we injected a total of 3 mg of methoxamine. Then SAS dropped to 50 mmHg. We injected epinephrine 0.2 mg twice and also started continuous infusion of norepinephrine. Severe skin rash indicated that anaphylactic reaction had occurred. About 20 minutes after starting norepinephrine, the SAS was stabilized. We decided to stop the operation, and the patient was moved to the intensive care unit (ICU). A few hours after entering the ICU, she was extubated and moved to the general ward next day. Skin-prick-tests performed 14 days later indicated that she was allergic to ephedrine, methoxamine, epinephrine, dopamine and a few more drugs.

[Immune mechanism of regulating the balance of chemical compounds of endogenous origin]

Specific autoantibodies of neutralizing character to histamine, serotonin, kallikrein, bradykuinine, acetylcholine, adrenalin, noradrenalin, insulin, and to the serotonin metabolite--5-hydroxyindolacetic acid, were found in donor serum (47.2%) and in intact rabbits, guinea pigs, rats, and mice (24.4%). Anti0odies to histamine, serotonin, kallikrein were found in a number of samples of commercial gamma-globulin. They were relatively often observed during the morning and day-time hours, in summer and in winter, in luteal phase of menstrual cycle, early in pregnancy (6-8 weeks), after surgical treatment, burns, inflammation, administration of foreign albumin, in the course of immunization by different antigens. The results of fractional analysis of serum showed that antibodies belonged to immunoglobulins with the constant of sedimantation 7S and 19S. The data obtained suggest the existence of an immune mechanism for the content regulation of different substances of endogenous origination in any organism.

[Autoimmune reactions in experimental pathology of the hippocampus]

Experimental hippocampal pathology caused by the local electrolytic lesion of the dorsal hippocampal area was shown to induce synthesis of antibodies to neurotransmitters (epinephrine and serotonin) and to hippocampal, heart and lung tissue antigens.