Effects of acute stress-induced immunomodulation on TH1/TH2 cytokine and catecholamine receptor expression in human peripheral blood cells

Role of Exercise Intensity on Th1/Th2 Immune Modulations During the COVID-19 Pandemic

The COVID-19 pandemic has led to several pioneering scientific discoveries resulting in no effective solutions with the exception of vaccination. Moderate exercise is a significant non-pharmacological strategy, to reduce the infection-related burden of COVID-19, especially in patients who are obese, elderly, and with additional comorbidities. The imbalance of T helper type 1 (Th1) or T helper type 2 (Th2) cells has been well documented among populations who have suffered as a result of the COVID-19 pandemic, and who are at maximum risk of infection and mortality. Moderate and low intensity exercise can benefit persons at risk from the disease and survivors by favorable modulation in Th1/Th2 ratios. Moreover, in COVID-19 patients, mild to moderate intensity aerobic exercise also increases immune system function but high intensity aerobic exercise may have adverse effects on immune responses. In addition, sustained hypoxia in COVID-19 patients has been reported to cause organ failure and cell death. Hypoxic conditions have also been highlighted to be triggered in COVID-19-susceptible individuals and COVID-19 survivors. This suggests that hypoxia inducible factor (HIF 1α) might be an important focus for researchers investigating effective strategies to minimize the effects of the pandemic. Intermittent hypoxic preconditioning (IHP) is a method of exposing subjects to short bouts of moderate hypoxia interspersed with brief periods of normal oxygen concentrations (recovery). This methodology inhibits the production of pro-inflammatory factors, activates HIF-1α to activate target genes, and subsequently leads to a higher production of red blood cells and hemoglobin. This increases angiogenesis and increases oxygen transport capacity. These factors can help alleviate virus induced cardiopulmonary hemodynamic disorders and endothelial dysfunction. Therefore, during the COVID-19 pandemic we propose that populations should engage in low to moderate exercise individually designed, prescribed and specific, that utilizes IHP including pranayama (yoga), swimming and high-altitude hiking exercise. This would be beneficial in affecting HIF-1α to combat the disease and its severity. Therefore, the promotion of certain exercises should be considered by all sections of the population. However, exercise recommendations and prescription for COVID-19 patients should be structured to match individual levels of capability and adaptability.

Analysis of the dynamic changes in the proportion of immune cells and the proportion of cells with stem cell characteristics in the corresponding immune cell population of C57 mice during the natural aging process

The aging of the immune system is not only an inevitable result but also an important cause of physical aging. The aging of the immune system is rooted in the aging of hematopoietic cells (HSCs), which manifests as decreasing functionality of the adaptive immune system and the innate immune system. C57BL/6 mice of different ages were collected in this study to better understand the changes in the structures of the innate and adaptive immune systems in individuals of different ages and the distribution and changes in immune cells with stem cell properties. The immune cells of the innate and adaptive immune systems, including DCs, monocytes, macrophages, CD4⁺ T lymphocytes, CD8⁺ T lymphocytes, and B lymphocytes, were assessed, and the proportions of cells with stem cell properties among these immune cell populations were also tested. Overall, immune cells in the peripheral blood, spleen, and bone marrow of mice exhibit certain regular properties with increasing age. The trend of changes in immune cells in different immune organs differs with age. The changes in lymphocytes in the peripheral blood are more sensitive. Their proportions increase slowly with age and then decrease rapidly to a very low level (less than 5%) after a certain point (9 or 13 months old). Nine to 13 months of age is the most critical time point for assessing changes in the immune system of mice and the most critical time point for detecting changes in the proportion of stem cells. After 13 months of age, the balance and stability of stem cells in mice are disrupted, and animals begin to age rapidly. The ratio of Ly6A to E⁺CD117⁺ cells in the peripheral blood, particularly lymphocytes involved in adaptive immunity, represents a specific marker for predicting immune senescence and body senescence.

Mechanisms of Immunotoxicity: Stressors and Evaluators

The immune system defends the body against certain tumor cells and against foreign agents such as fungi, parasites, bacteria, and viruses. One of its main roles is to distinguish endogenous components from non-self-components. An unproperly functioning immune system is prone to primary immune deficiencies caused by either primary immune deficiencies such as genetic defects or secondary immune deficiencies such as physical, chemical, and in some instances, psychological stressors. In the manuscript, we will provide a brief overview of the immune system and immunotoxicology. We will also describe the biochemical mechanisms of immunotoxicants and how to evaluate immunotoxicity.

Are prenatal anxiety or depression symptoms associated with asthma or atopic diseases throughout the offspring's childhood? An updated systematic review and meta-analysis

Background

Asthma is the most common respiratory disease among children, while atopic diseases such as atopic dermatitis affect about 20% of infants under 2 years of age. Studies suggested that these conditions might be related to prenatal depression or anxiety. This study aimed to explore the association between prenatal mental disorders and childhood asthma or atopic disease in a systematic review and meta-analysis.

Methods

PubMed, Embase, and the Cochrane Library were searched up to May 2020. The primary outcome was childhood asthma and childhood atopic dermatitis. Random-effects models were used because of high heterogeneity indicated by I² > 50% and Q-test P < 0.10.

Results

A total of 598 studies were initially identified, but nine studies met the inclusion criteria. Prenatal mental disorder was associated with childhood asthma (n = 6 studies; ES = 1.146, 95%CI: 1.054–1.245, P = 0.001; I² = 93.5%, P_{heterogeneity} < 0.001) whereas no significant association was found for childhood atopic dermatitis (n = 4 studies; ES = 1.211, 95%CI: 0.982–1.494, P = 0.073; I² = 78.5%, P_{heterogeneity} < 0.001). Childhood asthma seems to be related more to depression (n = 1 study; ES = 1.170, 95%CI: 1.061–1.291, P = 0.002) and anxiety/depression (n = 4 studies; ES = 1.157, 95%CI: 1.050–1.275, P = 0.073; I² = 95.3%, P_{heterogeneity} < 0.001).

Conclusion

This meta-analysis demonstrated that prenatal mental disorders increase the risk of childhood asthma. We limited the included samples to pregnant women to investigate the association between prenatal psychological factors and offspring’s physical health. Future studies should include large high-quality cohort studies to investigate the behavioral, environmental, and genetic causes for this association.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03909-z.

Does the Stress of Laboratory Life and Experimentation on Animals Adversely Affect Research Data? A Critical Review

Recurrent acute and/or chronic stress can affect all vertebrate species, and can have serious consequences. It is increasingly and widely appreciated that laboratory animals experience significant and repeated stress, which is unavoidable and is caused by many aspects of laboratory life, such as captivity, transport, noise, handling, restraint and other procedures, as well as the experimental procedures applied to them. Such stress is difficult to mitigate, and lack of significant desensitisation/habituation can result in considerable psychological and physiological welfare problems, which are mediated by the activation of various neuroendocrine networks that have numerous and pervasive effects. Psychological damage can be reflected in stereotypical behaviours, including repetitive pacing and circling, and even self-harm. Physical consequences include adverse effects on immune function, inflammatory responses, metabolism, and disease susceptibility and progression. Further, some of these effects are epigenetic, and are therefore potentially transgenerational: the biology of animals whose parents/grandparents were wild-caught and/or have experienced chronic stress in laboratories could be altered, as compared to free-living individuals. It is argued that these effects must have consequences for the reliability of experimental data and their extrapolation to humans, and this may not be recognised sufficiently among those who use animals in experiments.

Stress, mindfulness, and the allergic patient

INTRODUCTION

The global incidence and prevalence of allergic diseases are increasing as is the intensity and duration of excessive psychological stress due to multiple factors associated with living in today's world such as personal, social and political unrest, increased fear and anxiety, and/or depression often leading to hopelessness. Both allergy and chronic psychological stress are characterized by immune imbalances that have similar characteristics. Thus, it is reasonable to posit that the two are interactive and stress may induce as well as complicate at least some allergic diseases. Areas covered: Stress management/reduction has been proposed with various physical, pharmacological, and psychological interventions for both preventive and therapeutic reasons. A useful intervention involves mindfulness techniques, which allow the individual to put their life situation in context for better personal management. Expert commentary: Future studies must be developed that will further examine the role of excess psychological stress in specific allergic diseases and evaluate the effectiveness of various stress intervention protocols, particularly those involving mindfulness, to determine which individual would best respond clinically to which intervention. When this is accomplished, assessment and treatment of psychological stress will become a standard component of clinical care for allergy, asthma, and other immune-based diseases.

Perioperative inhibition of β-adrenergic and COX2 signaling in a clinical trial in breast cancer patients improves tumor Ki-67 expression, serum cytokine levels, and PBMCs transcriptome

Catecholamines and prostaglandins are secreted abundantly during the perioperative period in response to stress and surgery, and were shown by translational studies to promote tumor metastasis. Here, in a phase-II biomarker clinical trial in breast cancer patients (n = 38), we tested the combined perioperative use of the β-blocker, propranolol, and the COX2-inhibitor, etodolac, scheduled for 11 consecutive perioperative days, starting 5 days before surgery. Blood samples were taken before treatment (T1), on the mornings before and after surgery (T2&T3), and after treatment cessation (T4). Drugs were well tolerated. Results based on a-priori hypotheses indicated that already before surgery (T2), serum levels of pro-inflammatory IL-6, CRP, and IFNγ, and anti-inflammatory, cortisol and IL-10, increased. At T2 and/or T3, drug treatment reduced serum levels of the above pro-inflammatory cytokines and of TRAIL, as well as activity of multiple inflammation-related transcription factors (including NFκB, STAT3, ISRE), but not serum levels of cortisol, IL-10, IL-18, IL-8, VEGF and TNFα. In the excised tumor, treatment reduced the expression of the proliferation marker Ki-67, and positively affected its transcription factors SP1 and AhR. Exploratory analyses of transcriptome modulation in PBMCs revealed treatment-induced improvement at T2/T3 in several transcription factors that in primary tumors indicate poor prognosis (CUX1, THRa, EVI1, RORa, PBX1, and T3R), angiogenesis (YY1), EMT (GATA1 and deltaEF1/ZEB1), proliferation (GATA2), and glucocorticoids response (GRE), while increasing the activity of the oncogenes c-MYB and N-MYC. Overall, the drug treatment may benefit breast cancer patients through reducing systemic inflammation and pro-metastatic/pro-growth biomarkers in the excised tumor and PBMCs.

Assessment of Brain Derived Neurotrophic Factor in hair to study stress responses: A pilot investigation

To study pathogenic stress-effects in health and disease, it is paramount to define easy access parameters for non-invasive analysis of biological change in response to stress. Hair samples successfully provide this access for the study of hypothalamus-pituitary-adrenal axis (HPA) changes. In this study, we assess the hair expression and corresponding epigenetic changes of a neurotrophin essential for autonomic nervous system function and mental health: brain derived neurotrophic factor (BDNF). In three independent studies in healthy academic volunteers (study I: German students, N=36; study II, German academic population sample, N=28; study III: Mexican students, N=115), BDNF protein expression or BDNF gene (BDNF) histone acetylation was determined. Simultaneously, mental distress and distress-associated somatic complaints were assessed by self-report. In study I, we found a negative correlation between hair-BDNF protein level and hair-cortisol as well as between hair-BDNF and somatic complaints, while hair-cortisol correlated positively with mental distress. In study II, we found a negative correlation between H4 histone acetylation at the BDNF gene P4-promoter and somatic complaints. Regression analysis confirmed confounder stability of associations in both studies. In study III, we confirmed study I and found lower hair-BDNF protein level in volunteers with high somatic complaints, who also reported higher mental distress during the end of term exams. The results indicate that BDNF protein levels can be detected in clipped hair and are associated with somatic complaints and stress in life. In addition, we concluded that plucked hair can provide material for the study of epigenetic changes in stress-affected tissues. These tools can prove valuable for future studies on distress, both under experimental and field conditions.

Cytokine balance and behavioral intervention; findings from the Peer Approaches to Lupus Self-Management (PALS) project

The Peer Approaches to Lupus Self-Management program sought to address the disparate impact of systemic lupus erythematosus (SLE) on African American women through a peer mentoring intervention with aims of reducing stress, anxiety, and depression. Given the association between psychological health and immune function this study examines the relationship between patient reported outcomes (PROs) in these domains and immunologic indicators of disease activity. Twenty-three African American women with SLE served as mentees in the intervention from whom PRO measures were collected at the outset, midpoint, and end of the 12week pilot study. Blood samples were collected pre- and post-intervention. Plasma was collected from the samples and cryopreserved for subsequent analyses. The strongest correlations were between the Generalized Anxiety Disorder measure and Th1/Th2 cytokine balance. Weaker correlations existed between depression and the Th1/Th2 cytokine balance. Assessment of fresh versus cryopreserved samples revealed that changes in Th1/Th2 cytokine balance within the intervention were generally equivalent, regardless of sample type. The PALS intervention resulted in significant improvements to anxiety and depression levels which were significantly associated with positive changes in Th1/Th2 cytokine balance indicating a possible underlying mechanism of action. The nature of this relationship warrants further study.

Lifestyle Behaviors, Perceived Stress, and Inflammation of Individuals With Chronic Graft-Versus-Host Disease

BACKGROUND

Stress is a potent immunomodulator contributing to chronic conditions. Chronic graft-versus-host disease (cGVHD) is a life-threatening late effect of allogeneic hematopoietic cell transplantation associated with stress and exaggerated immune response that may be associated to lifestyle behaviors.

OBJECTIVE

The aim of this study is to explore associations among lifestyle behaviors, perceived stress, and inflammation of individuals with cGVHD.

METHODS

A secondary analysis from a prospective observational study of 24 adults (≥18 years) with cGVHD was conducted. Demographic, clinical, and symptom data were assessed using medical records and validated self-report measures; inflammatory markers were assessed using multiplex and enzyme-linked-immunosorbent assays from plasma.

RESULTS

Spiritual growth and total perceived stress were correlated (P < .001). Nutrition and C-reactive protein were negatively correlated (P = .02). Physical activity and cytokines (interleukin [IL]-2, IL-4, IL-5, IL-7, IL-10, IL-12, IL-13, IL-17, and granulocyte colony-stimulating factor) were associated (P < .05). Perceived stress and inflammatory markers were not associated. Individuals did not routinely engage in assessed health-promoting lifestyle behaviors.

CONCLUSION

Associations in this sample were noted among lifestyle behaviors, perceived stress, and inflammation. Given these promising findings, further research with a larger sample size is needed to test these associations. Activity, nutrition, stress management, and social support interventions may reduce stress and inflammation. Particularly, connecting with one's higher-self may reduce levels of perceived stress. Finding ways to engage survivors in healthy lifestyle behaviors should be explored.

IMPLICATIONS FOR PRACTICE

Information from this study allows nurses to be informed about the role of lifestyle behaviors on inflammation and stress to provide anticipatory guidance to HCT survivors regarding lifestyle choices that may mitigate inflammation and stress to promote positive health outcomes.

Depression as a systemic syndrome: mapping the feedback loops of major depressive disorder

BACKGROUND

Depression is a complex public health problem with considerable variation in treatment response. The systemic complexity of depression, or the feedback processes among diverse drivers of the disorder, contribute to the persistence of depression. This paper extends prior attempts to understand the complex causal feedback mechanisms that underlie depression by presenting the first broad boundary causal loop diagram of depression dynamics.

METHOD

We applied qualitative system dynamics methods to map the broad feedback mechanisms of depression. We used a structured approach to identify candidate causal mechanisms of depression in the literature. We assessed the strength of empirical support for each mechanism and prioritized those with support from validation studies. Through an iterative process, we synthesized the empirical literature and created a conceptual model of major depressive disorder.

RESULTS

The literature review and synthesis resulted in the development of the first causal loop diagram of reinforcing feedback processes of depression. It proposes candidate drivers of illness, or inertial factors, and their temporal functioning, as well as the interactions among drivers of depression. The final causal loop diagram defines 13 key reinforcing feedback loops that involve nine candidate drivers of depression.

CONCLUSIONS

Future research is needed to expand upon this initial model of depression dynamics. Quantitative extensions may result in a better understanding of the systemic syndrome of depression and contribute to personalized methods of evaluation, prevention and intervention.

Aggravation of Helicobacter pylori stomach infections in stressed military recruits

Objective

To investigate the effect of military stress on immune response and Helicobacter pylori stomach infections.

Methods

In this prospective, observational study, the Symptom Checklist-90 questionnaire was completed by military recruits before and following a 3-month basic training programme. H. pylori immunoglobulin (Ig)G levels, C¹⁴-urea breath-test values and levels of cortisol, catecholamine, and certain humoral and cellular immune responses were measured before and after the basic training.

Results

For 60 military recruits, somatization, depression and paranoid ideation scores were significantly increased after, compared with before, basic training. Post-training H. pylori IgG detection revealed three additional cases of H. pylori infection. Post-training C¹⁴-urea breath-test values were significantly higher compared with before training – thus suggesting higher levels of H. pylori colonization in the stomach. Post-training cortisol and catecholamine levels were increased, while serum IgG levels were decreased; complement component (C)3 and C4 levels remained unchanged. Post-training CD4⁺ and CD8⁺ T-cell percentages and the CD4⁺/CD8⁺ ratio were significantly reduced compared with before training. Serum interleukin (IL)-2 levels were lower and IL-10 levels were higher following training and there was a significant decrease in the IL-2/IL-10 ratio.

Conclusion

Military stress may reduce humoral and cellular immune responses and may aggravate the severity of H. pylori infection.

Sexual activity modulates shifts in TH1/TH2 cytokine profile across the menstrual cycle: an observational study

OBJECTIVE

To investigate if sexual activity moderated menstrual cycle-related shifts in cytokines associated with T-helper type 1 (TH1) cells (e.g., interferon [IFN] γ) and T-helper type 2 (TH2) cells (e.g., interleukin [IL] 4). Immune activity shifts across the menstrual cycle, with higher follicular-phase TH1-cell activity but higher luteal-phase TH2-cell activity. Little is known about how social behaviors alter TH1-TH2 ratios, despite evidence that psychosocial factors can influence immunity. Of particular interest is how sexual activity influences immune responses that may support conception, such as the TH1-TH2 balance.

DESIGN

Participants provided saliva samples at four time points (menstrual, follicular, ovulatory, and luteal phases), which were assayed by means of ELISA.

SETTING

Academic laboratory.

PARTICIPANT(S)

Thirty healthy premenopausal women (16 sexually abstinent, 14 sexually active) not taking hormonal or immunoactive medications.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Salivary E2, P, IFN-γ, and IL-4.

RESULT(S)

Sexually active, but not abstinent, women were significantly more likely to express TH2-like cytokine ratios (IFN-γ < IL-4) in the luteal phase than in other phases. Similarly, sexually active women had significantly higher P, and higher P-E2 ratios, in the luteal phase than did abstinent women. The P-E2 ratio mediated menstrual variations in cytokine ratios in sexually active women.

CONCLUSION(S)

These results support the hypothesis that shifts in immune response across the menstrual cycle may reflect tradeoffs between reproduction and immunity. These findings point to the need for further research on the interaction between sexual behavior, the menstrual cycle, and immune response.

Gene polymorphisms of stress hormone and cytokine receptors associate with immunomodulatory profile and psychological measurement

OBJECTIVE

We sought to identify whether stable single nucleotide polymorphisms (SNPs) of various endocrine and immune molecules could be used as biomarkers associated with specific immune alterations and chronic stress measures in normal humans.

METHODS

A total of 207 volunteer participants answered stress questionnaire and gave peripheral blood cells for identification of SNPs in genes coding for glucocorticoid receptor (GR), beta 2 adrenergic receptor (B2AR), interferon-gamma receptors (IFNGR1, IFNGR2), and interleukin-4 receptor (IL4R). Immunoregulatory profiles were measured by flow cytometry and genotyping assays were performed by allelic discrimination real-time PCR.

RESULTS

Several significant differences were revealed in associations between stress marker and immune indicators based on SNP categories. For instance, Th1 levels of the minor alleles of GR TthIIII (AA) and IFNGR2 Q64R (Arg/Arg) groups were positively associated with chronic stress (PSS) (p = 0.024 and 0.005, respectively) compared with wild type (WT) and negatively associated with PSS in the heterozygous genotypes of GR BclI and IL4R Ile50Val (p = 0.040 and p = 0.052, respectively). Treg levels of the minor alleles of BclI (GG) and IFNGR1 T-56C (CC) groups were positively associated with PSS (p = 0.045 and p = 0.010, respectively) and negatively associated in the minor allele (Val/Val) of IL4R Ile50Va and the heterozygous genotype of IL4R Q576R (p = 0.041 and p = 0.017, respectively) compared to WT.

CONCLUSION

The data support the notion that gene polymorphisms from various components of the psychoneuroendocrine-immune network may be useful as biomarkers to categorize individual stress-associated immune responses.

Regulation of differentiation and function of helper T cells by lymphocyte-derived catecholamines via α₁- and β₂-adrenoceptors

OBJECTIVE

Recently, we have reported that lymphocyte-derived endogenous catecholamines (CAs) facilitate a shift in the T helper (Th)1/Th2 balance towards Th2. The purpose of this study was to explore the involvement of adrenoreceptors (ARs) in Th differentiation and function modulation by lymphocyte-derived CAs.

METHODS

Lymphocytes were separated from the mesenteric lymph nodes of mice, stimulated with concanavalin A (Con A) and treated with pargyline, an inhibitor of CA degradation.

RESULTS

Pargyline downregulated the expression of Th1-relative factors, T-bet, interferon (IFN)-γ and interleukin (IL)-2, but upregulated the expression of Th2-relative factors, GATA-3, IL-4 and IL-10. Pargyline reduced the percentage of IFN-γ-producing CD4+ cells and the CD4+IFN-γ+/CD4+IL-4+ cell ratio, although it did not alter the proportion of IL-4-producing CD4+ cells. In addition, the percentage of CD4+CD26+ T cells and the CD4+CD26+/CD4+CD30+ cell ratio were also reduced in the pargyline-treated group. Furthermore, Con A-activated T cells treated with pargyline produced a lower level of IFN-γ and a higher level of IL-4 than the control group. All these effects were blocked by the α1-AR antagonist corynanthine or the β2-AR antagonist ICI 118551, but not by the α2-AR antagonist yohimbine or β1-AR antagonist atenolol.

CONCLUSIONS

These results imply that lymphocyte-derived CAs promote polarization of differentiation and function towards Th2 cells and that this effect is mediated by α1-AR and β2-AR.

A phase-specific neuroimmune model of clinical depression

Immune dysfunction and pro-inflammatory states in particular have been implicated in the aetiology and pathogenesis of depression. Whilst the onset of an episode and certain symptoms of depression appear well explained by this inflammatory model, the underpinnings of the episodic and progressive nature, as well as relapse and remission status in depression require attention. In this review it is suggested that additional immune factors beyond pro- and anti-inflammatory cytokines may effectively contribute to the understanding of the neurobiology of clinical depression. Considering neurobiological effects of immunomodulatory factors such as T cells, macrophages, microglia and astrocytes relevant to depression, we suggest a neuroimmune model of depression underpinned by dynamic immunomodulatory processes. This perspective paper then outlines a neuroimmune model of clinical phases of depression in an attempt to more adequately explain depression-like behaviours in pre-clinical models and the dynamic nature of depression in clinical populations. Finally, the implications for immunomodulatory treatments of depression are considered.

Effects of strenuous exercise on Th1/Th2 gene expression from human peripheral blood mononuclear cells of marathon participants

Physical stressors, such as strenuous exercise, can have numerous effects on the human body including the immune system. The aim of this study was to evaluate the gene expression profile of Th1/Th2 cytokines and related transcription factor genes in order to investigate possible immune imbalances before and after a marathon. Blood samples were collected from 16 normal volunteers 24-48 h before and one week after completing a marathon race. Gene expression of Th1 and Th2 related cytokines from human peripheral blood mononuclear cells (PBMC) was analyzed using Human Th1-Th2-Th3 RT(2) Profiler PCR Array and qRT-PCR that measured the transcript levels of 84 genes related to T cell activation. We found that PBMC express a characteristic Th2-like gene profile one week post-marathon compared to pre-marathon. The majority of genes up-regulated one week post-marathon such as IL-4, GATA3, and CCR4 were Th2 associated. For Th1-related genes, CXCR3 and IRF1 were up-regulated one week post-marathon. There was a trend of down-regulation of two Th1 related genes, T-bet and STAT1. Th3-related gene expression patterns did not change in the study. The ratios of both IFN-γ/IL-4 and T-bet/GATA3 gene expressions were significantly lower one week after marathon. These findings suggest that a Th1/Th2 immune imbalance persisted at least 1 week after completion of a marathon which offers a mechanistic rationale for the increased risk of upper respiratory tract infections often reported after strenuous exercise.

Airway nitric oxide and psychological processes in asthma and health: a review

OBJECTIVE

The fraction of exhaled nitric oxide (FeNO) has been widely used as a marker of airway inflammation in asthma in recent years. However, NO serves multiple functions throughout the organism, and various influences on FeNO levels beyond inflammation have been documented. Emerging literature indicates that psychological processes are systematically linked to FeNO.

DATA SOURCES

Academic Search Complete, PubMed, PsychArticles, and PsychInfo databases.

STUDY SELECTIONS

Relevant studies were identified using keywords exhaled nitric oxide paired with psychological stress, stress psychology, emotion, major depression, anxiety, or psychopathology. Studies measuring FeNO during naturalistic observation of emotion and stress, laboratory stress and emotion-induction protocols, and correlational designs using psychological questionnaires were included.

RESULTS

Acute stress, anxiety, and negative affect have been repeatedly linked with higher FeNO levels, whereas more prolonged states of stress, in particular depression, have been associated with lower FeNO levels. The literature on FeNO is paralleled by research on NO in the cardiovascular and central nervous systems, which also shows systematic associations with psychosocial variables. Potential mechanisms of association include stimulation of NO release from different cells, including the epithelia and macrophages, through noradrenaline, interferon-γ, or vascular endothelial growth factor, changes in oxidative stress or arginase levels, or facilitation of diffusion by mechanical factors.

CONCLUSION

Psychosocial factors may need to be considered in the interpretation of longitudinal FeNO changes in monitoring and management of patients with asthma. The distinction between constitutive and inducible sources of NO will be essential for future research.

Associations between cytokine receptor polymorphisms and variability in laboratory immune parameters in normal humans

In every study involving human immune parameters, large inter-subject variability occurs which can make interpretation of results difficult. The aim of this study was to evaluate whether genetic variants in cytokine receptors could associate with variability in laboratory immune measures. A total of 207 normal volunteers were recruited in this study. Immunoregulatory profiles were measured by flow cytometry and genotyping assays were performed by allelic discrimination real-time PCR. Immunoregulatory profiles were categorized according to various single nucleotide polymorphisms (SNPs) of cytokine receptors including T-56C and G-611A of IFN-γ receptor 1 (IFNGR1); Q64R of IFNGR2; and Ile50Val, Q576R and S503P of IL4R. Results reveal that Th1 levels were significantly higher in the heterozygous of the IFNGR1 T-56C polymorphism (minor allele) compared to wild-type (WT, major allele) (p = 0.006). For the Q576R of IL4R, Th1/Th2 ratio was significantly lower for the homozygous SNP (Arg/Arg) compared to the WT (Gln/Gln) (p = 0.035). In addition, the significant interaction effects of demographic characteristics on SNP-immune parameter associations were reported as well. We conclude that cytokine receptor polymorphisms might associate with variability in laboratory immune measures. Approach of SNP analysis of cytokine receptors can be useful in categorizing baseline immune responses to more accurately evaluate clinical immune data.

Immunomodulatory effects of dexamethasone on gene expression of cytokine and stress hormone receptors in peripheral blood mononuclear cells

Glucocorticoid (GC) such as cortisol in humans is a major stress hormone and can influence immunomodulation through various mechanisms including impact on regulatory T-cell (RTC) elements and changes in Th1/Th2 cytokine balance. In this study, we sought to determine the immunomodulatory effects of GC equivalent dexamethasone (DEX) at various concentrations (10(-7), 10(-8), and 10(-9) M) on gene expression of RTC, cytokine receptors and stress hormone receptors from normal human peripheral blood mononuclear cells (PBMC) in an in vitro stress model in 24 h (acute stress) vs 11-day (chronic stress) cultures. Results revealed that the mRNA of forkhead box P3 (FoxP3) was significantly decreased at 24 h with 10(-7) and 10(-8) M DEX. After 11 days, FoxP3 expression in the 10(-8) M DEX cultures had returned to baseline but was still down-regulated with 10(-7) M DEX. GC receptor (GR) mRNA decreased and β2 adrenergic receptor (β 2AR) mRNA increased significantly after 24 h exposure to DEX. These changes had returned to baseline in the 11-day cultures. The IFN-γR/IL-4R ratio, an alternative marker for Th1/Th2 balance, was significantly increased at 24 h and decreased after 11-day cultures with 10(-7) and 10(-8) M DEX compared to control cultures. These findings further contribute to our understanding of the mechanisms associated with the effects of acute vs. chronic stress on normal immune balance.

Psychosocial factors and hematopoietic stem cell transplantation: potential biobehavioral pathways

While psychosocial factors are known to affect cancer progression via biobehavioral pathways in many patient populations, these relationships remain largely unexplored in hematopoietic stem cell transplant (HCT) patients. The purpose of this paper is to critically review the literature regarding psychosocial and endocrine/immune aspects of HCT, with an emphasis on exploring pathways that may mediate the associations between psychosocial factors and disease outcomes. These include the roles of catecholamines, glucocorticoids, inflammation, vascular endothelial growth factor (VEGF), immune reconstitution and infectious susceptibility, as well as the new opportunities available in genomics research. We also discuss the implications for potential immunomodulating psychosocial interventions. Elucidating the biological pathways that account for the associations between psychosocial factors and clinical course could ultimately lead to improved outcomes for this psychologically and immunologically vulnerable population.

Parental psychological distress during pregnancy and wheezing in preschool children: the Generation R Study

BACKGROUND

Maternal psychological distress during pregnancy might affect fetal lung development and subsequently predispose children to childhood asthma.

OBJECTIVE

We sought to assess the associations of maternal psychological distress during pregnancy with early childhood wheezing.

METHODS

We performed a population-based prospective cohort study among 4848 children. We assessed maternal and paternal psychological distress at the second trimester of gestation and 3 years after delivery and maternal psychological distress at 2 and 6 months after delivery by using the Brief Symptom Inventory questionnaire. Wheezing in the children was annually examined by using questionnaires from 1 to 4 years. Physician-diagnosed ever asthma was reported at 6 years.

RESULTS

Mothers with psychological distress during pregnancy had increased odds of wheezing in their children from 1 to 4 years of life (overall distress: odds ratio [OR], 1.60 [95% CI, 1.32-1.93]; depression: OR, 1.46 [95% CI, 1.20-1.77]; and anxiety: OR, 1.39 [95% CI, 1.15-1.67]). We observed similar positive associations with the number of wheezing episodes, wheezing patterns, and physician-diagnosed asthma at 6 years. Paternal distress during pregnancy and maternal and paternal distress after delivery did not affect these results and were not associated with childhood wheezing.

CONCLUSION

Maternal psychological distress during pregnancy is associated with increased odds of wheezing in their children during the first 6 years of life independent of paternal psychological distress during pregnancy and maternal and paternal psychological distress after delivery. These results suggest a possible intrauterine programming effect of maternal psychological distress leading to respiratory morbidity.

The impact of self-reported psychological stress levels on changes to peripheral blood immune biomarkers in recreational marathon runners during training and recovery

OBJECTIVE

Marathon training is both physically and psychologically stressful, both of which can lead to altered immunity. The purpose of this study was to determine if the overall immunoregulatory changes associated with the physical stress of marathon training are affected by psychological stress.

METHODS

Nineteen recreational marathoners completed the Perceived Stress Scale (PSS), State-Trait Anxiety Inventory (STAI) and Penn State Worry Questionnaire (PSWQ), and had levels of T cell subpopulations and cytokine (IFNγ, IL4 and IL10) production determined 4 weeks before (baseline), 24-48 h before (prerace) and 1 week after (recovery) participation in a marathon.

RESULTS

PSS scores decreased at the prerace visit compared to baseline and remained low at recovery. Compared to baseline, there were significant changes to numerous immune measures at the prerace visit, including decreases in Th1/Th2 ratio, Tc1/Tc2 ratio, Tr1 and Th3 cell populations as well as decreases in IFNγ/IL4 cytokine ratio and IL10 production. Most immune parameters had returned to near baseline values at the recovery visit. Higher levels of perceived stress, anxiety and worry exacerbated many of the alterations in immunity that were observed at the prerace visit. Higher levels of perceived stress and worry had significant effects on changes to Treg, IL4 production and the IFNγ/IL4 cytokine ratio. Stress had an additional impact on changes in IL10 production. High anxiety levels resulted in significant changes to Treg, Tr1 and Th3.

CONCLUSION

These data suggest that recreational marathon runners with higher levels of psychological stress may be more at risk for the immune alterations that are common during periods of prolonged physical training.

Glucocorticoid receptor BclI polymorphism associates with immunomodulatory response to stress hormone in human peripheral blood mononuclear cells

Glucocorticoid receptor (GR) variants have been found to be associated with stress-related disorders. Our previous in vivo study revealed that the CC allele of GR BclI single-nucleotide polymorphism (SNP) was more common in the high-stress group, which had lower levels of both regulatory T cells (Treg) and Th1 cytokine. The current study was to investigate the associations between GR BclI polymorphism and immunomodulatory response to stress hormone in vitro in human peripheral blood mononuclear cells (PBMC). Blood samples were collected from 18 normal volunteers including 9 subjects with BclI polymorphism GG allele and 9 with wild-type (WT) CC allele. PBMC were cultured with 10(-8) m dexamethasone (DEX), which mimics the plasma cortisol level observed during periods of psychological stress for 24 h and 11 days. Gene expressions of transcription factors, stress hormone and cytokine receptors were analysed by real-time RT-PCR. FoxP3 mRNA was significantly altered in the BclI WT (decreased at 24 h and increased at 11 days) but not in the GG allele. GR mRNA was up-regulated at 24 h and down-regulated at 11 days in CC alleles (P < 0.01 and P < 0.05), rather than in GG alleles. The expression of β-2 adrenergic receptor (β2AR) was increased at 24 h in both CC and GG alleles (P < 0.01 and P < 0.001), but decreased significantly at 11 days in only GG alleles. Expression of T-bet and GATA-3 was altered simultaneously in 24-h culture with DEX from both groups. The BclI polymorphism of GR identifies different immunomodulatory responses to corticosteroids, which may explain, at least in part, the variability in individual sensitivity to stressors.

Variability in laboratory immune parameters is associated with stress hormone receptor polymorphisms

OBJECTIVES

Interpretation of laboratory immune data in healthy human subjects is often challenging due to wide inter-subject variability. Since endocrine and immune mediators have been mutually interlinked, a potential explanation for the significant variability seen in immune data even when controlled for technical variability and demographics is differences in the binding affinity of ligand with hormone receptors on the surface of immune cells, which can be associated with single nucleotide polymorphisms (SNP).

METHODS

We categorized immunoregulatory cellular profiles from PBMC of 207 healthy volunteers according to glucocorticoid receptor (GR: Bcl1, TthIIII, and A3669G) and β₂-adrenergic receptor (β2AR: Gly16Arg and Gln27Glu) polymorphisms. Subjects were genotyped for each SNP, and Th1, Th2, Th1/Th2 ratio, regulatory T cell (T(reg)), Tr1, and Th3 cell numbers were assessed. Immune parameters in the SNP groups were compared to the wild type (WT).

RESULTS

Significant differences were observed in Th2 and the Th1/Th2 ratio for the β2AR SNP Gly16Arg. Th1, the Th1/Th2 ratio, and Tr1 differed significantly by SNP of Gln27Glu. In addition, the effect of age on Th2 and the effect of the body mass index on the Th1/Th2 ratio significantly differed across subtypes of the Gly16Arg SNP. Significant differences based on allergic status and gender were also seen for T(reg), Th1, and Th2 across Gly16Arg, Gln27Glu, and TthIIII SNP.

CONCLUSIONS

These data suggest that SNP from various components of the stress-immune network may be useful for subgrouping of immune responses to more accurately categorize psychoneuroimmunological components of stress risk in individual subjects. This approach may have significant research and clinical potential.