Early adversity, immunity and infectious disease

Public healthcare disparities in Africa: the food production systems and its dichotomy in a South African context

One of the major concerns of development in Africa is the issue of public health. In Africa, public healthcare has been and still is a problem most African countries are faced with. The problem of public healthcare seems to be unabated even though there are measures that are put in place for its effectiveness. There is hunger, malnutrition, high mortality rate, illnesses and deterioration of life expectancy in most developing countries of Africa. The dramatic unprecedented public health disparity has become a scourge in developing countries where it has purportedly impaired the developmental efforts, economic growth and prosperity. As a result, there is a need to scrutinize possible causes that exacerbates public health issues in developing countries. The paper argues that the current food production system (conventional) contributes to current status of public health as compared to the previous food production system (organic). The purpose of this paper is to conceptualize public healthcare disparities, juxtaposing organic and conventional food production that result as human food consumption. The paper employs literature-based analysis as a methodology to assemble data in respect of public healthcare disparities and food production systems.

Prenatal and early life exposure to air pollution and the risk of severe lower respiratory tract infections during early childhood: the Espoo Cohort Study

BACKGROUND

There is inconsistent evidence of the effects of exposure to ambient air pollution on the occurrence of lower respiratory tract infections (LRTIs) in early childhood. We assessed the effects of individual-level prenatal and early life exposure to air pollutants on the risk of LRTIs in early life.

METHODS

We studied 2568 members of the population-based Espoo Cohort Study born between 1984 and 1990 and living in 1991 in the City of Espoo, Finland. Exposure assessment was based on dispersion modelling and land-use regression for lifetime residential addresses. The outcome was a LRTI based on data from hospital registers. We applied Poisson regression to estimate the incidence rate ratio (IRR) of LTRIs, contrasting incidence rates in the exposure quartiles to the incidence rates in the first quartile. We used weighted quantile sum (WQS) regression to estimate the joint effect of the studied air pollutants.

RESULTS

The risk of LRTIs during the first 2 years of life was significantly related to exposure to individual and multiple air pollutants, measured with the Multipollutant Index (MPI), including primarily sulphur dioxide (SO2), particulate matter with a dry diameter of up to 2.5 µm (PM2.5) and nitrogen dioxide (NO2) exposures in the first year of life, with an adjusted IRR of 1.72 per unit increase in MPI (95% CI 1.20 to 2.47). LRTIs were not related to prenatal exposure.

CONCLUSIONS

We provide evidence that ambient air pollution exposure during the first year of life increases the risk of LRTIs during the first 2 years of life. SO2, PM2.5 and NO2 were found to contribute the highest weights on health effects.

Early social deprivation does not affect cortisol response to acute and chronic stress in zebrafish

Social isolation is a well-established technique for inducing early adversity but, in rodent models, the need of parental care makes it difficult to distinguish the effects of social deprivation from the consequences of nutritional deficiencies. Zebrafish do not require parental care, allowing separation of social deprivation from nutritional deprivation, and have emerged as a promising model to study ontogeny of normal and pathological behaviors relevant for human neuropsychological disorders. Previous reports of life-long isolation in zebrafish showed some consistency with mammalian literature, depicting later social deficits and locomotor hyperactivity. However, unlike reports of higher anxiety and stress behavior in isolated rodents and primates, behavioral responses were tapered in isolated fish. To examine whether life-long developmental isolation has a dampening effect on zebrafish endocrine stress response, we applied stressors to zebrafish siblings that were either isolated or socialized, and compared their whole-body cortisol levels with non-stressed control siblings kept in low-housing densities. Utilizing previously validated paradigms (exposure to novel tank and unpredictable chronic stress), we exposed separate groups (n = 9-14, mixed-sex) of social and isolated zebrafish to acute and chronic stressors and measured their cortisol levels. A univariate ANOVA and post-hoc Tukey's HSD tests confirmed that compared to socially raised control fish, developmental isolation did not increase baseline cortisol levels in zebrafish. Additionally, compared to the non-stressed condition, application of both acute and chronic stressors significantly increased cortisol levels in isolated fish and, to a similar degree, to socially raised fish. Our findings suggest that zebrafish isolation studies may help separate effects of social deprivation from nonsocial aspects of early adversity. These studies further substantiate the use of developmental isolation in zebrafish, particularly with acute and chronic stress paradigms, for modeling neuropsychological disorders.LAY SUMMARYA difficult childhood can make humans react more frequently or severely to later stress and modeling this effect in animals can help explain how and why early stress affects subsequent mental and physical health. Early social isolation does not affect later response to stressful situations in adult zebrafish, providing us with a model of psychiatric disorders that allows separation of effects of poor physical environments (lacking food, shelter, etc.) from poor social environments (lack of appropriate socialization).

Is early life adversity a trigger towards inflammageing?

There are many 'faces' of early life adversity (ELA), such as childhood trauma, institutionalisation, abuse or exposure to environmental toxins. These have been implicated in the onset and severity of a wide range of chronic non-communicable diseases later in life. The later-life disease risk has a well-established immunological component. This raises the question as to whether accelerated immune-ageing mechanistically links early-life adversity to the lifelong health trajectory resulting in either 'poor' or 'healthy' ageing. Here we examine observational and mechanistic studies of ELA and inflammageing, highlighting common and distinct features in these two life stages. Many biological processes appear in common including reduction in telomere length, increased immunosenescence, metabolic distortions and chronic (viral) infections. We propose that ELA shapes the developing immune, endocrine and nervous system in a non-reversible way, creating a distinct phenotype with accelerated immunosenescence and systemic inflammation. We conclude that ELA might act as an accelerator for inflammageing and age-related diseases. Furthermore, we now have the tools and cohorts to be able to dissect the interaction between ELA and later life phenotype. This should, in the near future, allow us to identify the ecological and mechanistic processes that are involved in 'healthy' or accelerated immune-ageing.

Insects Provide Unique Systems to Investigate How Early-Life Experience Alters the Brain and Behavior

Early-life experiences have strong and long-lasting consequences for behavior in a surprising diversity of animals. Determining which environmental inputs cause behavioral change, how this information becomes neurobiologically encoded, and the functional consequences of these changes remain fundamental puzzles relevant to diverse fields from evolutionary biology to the health sciences. Here we explore how insects provide unique opportunities for comparative study of developmental behavioral plasticity. Insects have sophisticated behavior and cognitive abilities, and they are frequently studied in their natural environments, which provides an ecological and adaptive perspective that is often more limited in lab-based vertebrate models. A range of cues, from relatively simple cues like temperature to complex social information, influence insect behavior. This variety provides experimentally tractable opportunities to study diverse neural plasticity mechanisms. Insects also have a wide range of neurodevelopmental trajectories while sharing many developmental plasticity mechanisms with vertebrates. In addition, some insects retain only subsets of their juvenile neuronal population in adulthood, narrowing the targets for detailed study of cellular plasticity mechanisms. Insects and vertebrates share many of the same knowledge gaps pertaining to developmental behavioral plasticity. Combined with the extensive study of insect behavior under natural conditions and their experimental tractability, insect systems may be uniquely qualified to address some of the biggest unanswered questions in this field.

Preconceptional and prenatal exposure to air pollution increases incidence of childhood pneumonia: A hypothesis of the (pre-)fetal origin of childhood pneumonia

BACKGROUND

Increasing evidence has linked childhood pneumonia with early exposure to ambient air pollution. However, the impact of exposure to air pollutants before birth is unclear.

OBJECTIVE

To further clarify whether exposure to a particular pollutant during preconceptional and prenatal periods, may pose a higher risk of developing childhood pneumonia.

METHODS

This case-control cohort study consisted of 1510 children aged 0-14 years in Changsha, China between 2017 and 2019. Data of children's history of pneumonia and blood biomarkers were obtained from the XiangYa Hospital records. Each child's exposure to air pollutants, including nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and particulate matter with an aerodynamic diameter ≤ 10 µm (PM₁₀), was calculated using data from ten air pollution monitoring stations. A multivariate logistic regression model was used to quantify the relationship between childhood pneumonia and exposure to ambient air pollution during the preconceptional and prenatal periods.

RESULTS

Childhood pneumonia was significantly associated with preconceptional and prenatal exposure to the industrial-related air pollutant, SO₂, for 1 year before conception, for 3 months before conception and for the entire pregnancy, with ORs(95% CI)= 4.01(3.17-5.07), 4.06(3.29-5.00) and 6.51(4.82-8.79). Also, children who were sick with pneumonia had higher white blood cell and neutrophil counts, and children with low eosinophil count or hemoglobin are likely to get pneumonia. Sensitivity analysis showed that boys, and children in high temperature area were susceptible to the effect of both preconceptional and prenatal exposure to industrial SO₂.

CONCLUSION

Preconceptional and prenatal exposure to industrial-related air pollution plays a significant role in the incidence and progression of childhood pneumonia, supporting the hypothesis of "(pre-)fetal origin of childhood pneumonia".

Maternal prenatal stress exposure and sex-specific risk of severe infection in offspring

Background

Maternal stressful life events during pregnancy have been associated with immune dysregulation and increased risk for asthma and atopy in offspring. Few studies have investigated whether prenatal stress is associated with increased overall or specific infectious diseases in childhood, nor explored sex differences. We sought to examine the relationship between the nature and timing of maternal stress in pregnancy and hospitalisation with infection in offspring.

Methods

Between 1989 and 1992, exposure data on stressful life events were collected from pregnant women (Gen1) in the Raine Study at 18 and 34 weeks’ gestation and linked to statutory state-wide hospital morbidity data. We examined associations between the number, category and timing of maternal prenatal stress events and overall and clinical groups of offspring (Gen2) infection-related hospitalisation until age 16 years, adjusting for maternal age, education, and smoking in pregnancy in addition to the presence of siblings at birth.

Results

Of 2,141 offspring with complete stress in pregnancy data available, 1,089 had at least one infection-related hospitalisation, with upper respiratory tract infections the most common (n = 556). Each additional stressful life event during pregnancy was associated with increased risk in male offspring for hospitalisation with all infection types. There was little evidence of these associations in girls.

Conclusions

Increased exposure to stressful life events in utero is associated with sex-specific infection-related hospitalisations in childhood. Prenatal stress may adversely affect early immune development for boys and increase the risk of more severe infections. Mechanistic understanding would inform preventative interventions.

Relationship between Child Sexual Abuse, Psychiatric Disorders and Infectious Diseases: A Matched-Cohort Study

Child sexual abuse (CSA) has been strongly associated with a range of psychological and physical problems in childhood and adulthood, such as anxiety, post-traumatic stress disorder (PTSD), and infectious diseases. Despite the strength of these associations, no studies to date have investigated psychobiological processes that might underlie the relationship between CSA and physical health problems occurring during childhood, such as infectious diseases. The goal of the current study is to evaluate PTSD as a potential mediator between CSA and the occurrence of infectious diseases among children and adolescents. Furthermore, we postulate that PTSD plays a specific role as an indicator of chronic stress during childhood, in comparison to other mental disorders, such as anxious and non-anxious disorders (e.g., depression). Via a prospective matched-cohort design, administrative data were used to document PTSD, anxious and non-anxious disorders, and infectious diseases. The sample size was 882 persons with a substantiated report of sexual abuse and 882 matched controls. Negative binomial regressions revealed that CSA is associated with a greater number of anxious diseases diagnoses that, in turn, predict more infectious diseases diagnoses. These findings highlight the importance of preventing and intervening among sexually abused youth with anxious disorder symptoms to limit negative outcomes on physical health.

Modulation of T helper 1 and T helper 2 immune balance in a murine stress model during Chlamydia muridarum genital infection

A murine model to study the effect of cold-induced stress (CIS) on Chlamydia muridarum genital infection and immune response has been developed in our laboratory. Previous results in the lab show that CIS increases the intensity of chlamydia genital infection, but little is known about the effects and mechanisms of CIS on the differentiation and activities of CD4+ T cell subpopulations and bone marrow-derived dendritic cells (BMDCs). The factors that regulate the production of T helper 1 (Th1) or T helper 2 (Th2) cytokines are not well defined. In this study, we examined whether CIS modulates the expressions of beta-adrenergic receptor (β-AR), transcription factors, hallmark cytokines of Th1 and Th2, and differentiation of BMDCs during C. muridarum genital infection in the murine model. Our results show that the mRNA level of the beta2-adrenergic receptor (β2-AR) compared to β1-AR and β3-AR was high in the mixed populations of CD4+ T cells and BMDCs. Furthermore, we observed decreased expression of T-bet, low level of Interferon-gamma (IFN-γ) production, increased expression of GATA-3, and Interleukin-4 (IL-4) production in CD4+ T cells of stressed mice. Exposure of BMDCs to Fenoterol, β2-AR agonist, or ICI118,551, β2-AR antagonist, revealed significant β2-AR stimulation or inhibition, respectively, in stressed mice. Moreover, co-culturing of mature BMDCs and naïve CD4+ T cells increased the production of IL-4, IL-10, L-17, and IL-23 cytokines, suggesting that stimulation of β2-AR leads to the increased production of Th2 cytokines. Overall, our results show for the first time that CIS promotes the switching from a Th1 to Th2 cytokine environment. This was evidenced in the murine stress model by the overexpression of GATA-3 concurrent with elevated IL-4 production, reduced T-bet expression, and IFN-γ secretion.

An Epigenetics-Based, Lifestyle Medicine-Driven Approach to Stress Management for Primary Patient Care: Implications for Medical Education

Over 75% of patients in the primary care setting present with stress-related complaints. Curiously, patients and health care providers all too often see stress as a relatively benign sequela of many common illnesses such as heart disease, cancer, lung disease, dementia, diabetes, and mental illness. Unfortunately, various day-to-day lifestyle choices and environmental factors, unrelated to the presence of any disease, can cause stress sufficient to contribute to the development of various diseases/disorders and suboptimal health. There is evidence suggesting that counseling in stress management-oriented therapeutic interventions (as offered by lifestyle medicine-oriented practitioners) may prevent or reduce the onset, severity, duration, and/or overall burden of stress-related illnesses. Such counseling often involves considerations such as the patient's nutrition, physical activity, interest in/capacity to meditate, drug abuse/cessation, and so on. Unfortunately, lifestyle medicine-oriented approaches to stress management are rarely offered in primary care-the patient care arena wherein such counseling would likely be best received by patients. Would health care outcomes improve if primary care providers offered counseling in both stress management and positive lifestyle choices? The purpose of this article is to provide both primary care practitioners and educators in health care training programs with an introductory overview of epigenetics. An emerging field of science offering insights into how factors such as stress and lifestyle choices interact with our genes in ways that can both positively and negatively impact the various micro (eg, cellular) through macro (eg, physiologic, pathophysiologic) processes that determine our tendencies toward illness or wellness. A deeper understanding of epigenetics, as provided herein, should enable primary care providers and medical educators to more confidently advocate for the primary benefits associated with counseling in both stress reduction and the pursuit of healthy lifestyle choices.

Reprogramming of the Immune System by Stress and Faulty Hormonal Imprinting

PURPOSE

Hormonal imprinting is taking place perinatally at the first encounter between the developing hormone receptors and their target hormones. However, in this crucial period when the developmental window for physiological imprinting is open, other molecules, such as synthetic hormones and endocrine disruptors can bind to the receptors, leading to faulty imprinting with life-long consequences, especially to the immune system. This review presents the factors of stress and faulty hormonal imprinting that lead to reprogramming of the immune system.

METHODS

Relevant publications from Pubmed since 1990 were reviewed and synthesized.

FINDINGS

The developing immune system is rather sensitive to hormonal effects. Faulty hormonal imprinting is able to reprogram the original developmental program present in a given cell, with lifelong consequences, manifested in alteration of hormone binding by receptors, susceptibility to certain (non-infectious) diseases, and triggering of other diseases. As stress mobilizes the hypothalamic-pituitary-adrenal axis if it occurred during gestation or perinatally, it could lead to faulty hormonal imprinting in the immune system, manifested later as allergic and autoimmune diseases or weakness of normal immune defenses. Hormonal imprinting is an epigenetic process and is carried to the offspring without alteration of DNA base sequences. This means that any form of early-life stress alone or in association with hormonal imprinting could be associated with the developmental origin of health and disease (DOHaD). As puberty is also a period of reprogramming, stress or faulty imprinting can change the original (developmental) program, also with life-long consequences.

IMPLICATIONS

Considering the continuous differentiation of immune cells (from blast-cells) during the whole life, there is a possibility of late-imprinting or stress-activated reprogramming in the immune system at any periods of life, with later pathogenetic consequences.

Meconium-stained amniotic fluid exposure is associated with a lower incidence of offspring long-term infectious morbidity

OBJECTIVE

Meconium-stained amniotic fluid (MSAF) is a well-established risk factor for immediate adverse neonatal outcomes and was recently suggested to be associated with microbial invasion of the amniotic cavity. We aimed to determine whether MSAF exposure during labor carries a longer lasting impact on pediatric infectious morbidity.

STUDY DESIGN

A population-based cohort analysis was performed including all singleton deliveries occurring between 1991 and 2014 at a single tertiary medical center. Exposure was defined as the presence of MSAF during labor. Hospitalizations of the offspring up to the age of 18 years involving infectious diseases were evaluated. A Kaplan-Meier survival curve was used to compare cumulative morbidity and a Cox regression model to control for confounders.

RESULTS

During the study period, 243 725 deliveries met the inclusion criteria. Of them, 35 897 (14.7%) involved MSAF. Rate of infectious-related hospitalizations of the offspring was significantly lower in children exposed to MSAF as compared with the unexposed group (10.8% vs 11.1%, P < 0.05). Specifically, hospitalizations involving respiratory infections were significantly less common among the MSAF group (5.1% vs 5.6%, P < 0.001). The survival curve demonstrated significantly lower cumulative total infectious morbidity rates in the MSAF-exposed group (log rank P < 0.001). In the Cox model, controlled for maternal age, diabetes, hypertension, mode of delivery, and gestational age, exposed children exhibited lower rates of long-term childhood infectious morbidity (adjusted HR 0.96, 95% CI 0.92-0.99, P < 0.001).

CONCLUSION

Fetal exposure to MSAF during labor and delivery appears to be associated with lower rates of long-term infectious-related hospitalizations in the offspring.

Blood cell count in antipsychotic-naive patients with non-affective psychosis

BACKGROUND

Schizophrenia is a complex medical entity with a reduced life expectancy, mostly due to an increased prevalence of cardiovascular diseases compared to the general population. An unbalanced immune response and a pro-inflammatory state might underlie this process. In treated patients, abnormal white blood cell (WBC), lymphocyte and neutrophil count suggests atypical immune response related to clinical variables. We aimed to test the hypothesis that newly diagnosed naïve patients with non-affective psychosis would show abnormal blood cell count values after controlling for potential confounding factors compared to matched controls.

METHODS

Seventy-five patients were compared with 80 controls matched for age, gender, body mass index and smoking. Analyses were conducted before and after controlling for smoking.

RESULTS

Patients and controls displayed similar mean values (×10³ /μL [SD]) for WBC count 7.02 [2.2] vs 6.50 [1.7] (P = .159), neutrophil count 4.25 [1.8] vs 3.84 [1.3] (P = .110) and monocyte count 0.43 [0.2] vs 0.40 [0.1] (P = .326). After controlling for smoking, 38 non-smoking patients showed a higher WBC and neutrophil count compared with 49 matched controls. Respective means of 7.01 [2.2] vs 5.97 [1.4] (P = .011) for WBC and 4.24 [1.9] vs 3.51 [1.2] (P = .028) for neutrophil count. Monocyte count showed an increased mean value 0.43 [0.2] vs 0.36 [0.1] with a trend towards signification (P = .063).

CONCLUSIONS

These results suggest that abnormal immune response is present before the effects of medication and other confounders had taken place. Increased immune parameters might underlie the high ratio of medical co-morbidities described in schizophrenia.

Early-life adversity programs long-term cytokine and microglia expression within the HPA axis in female Japanese quail

Stress exposure during pre and post-natal development can have persistent and often dysfunctional effects on several physiological systems, including immune function, affecting the ability to combat infection. The neuro-immune response is inextricably linked to the action of the Hypothalamic Pituitary Adrenal (HPA) axis. Cytokines released from neuro-immune cells, including microglia, activate the HPA axis while glucocorticoids in turn regulate cytokine release from microglia. Because of the close links between these two physiological systems, coupled with potential for persistent changes to HPA axis activity following developmental stress, components of the neuro-immune system could be targets for developmental programming. However, little is known of any programming effects of developmental stress on neuro-immune function. We investigated whether developmental stress exposure via elevated pre-natal corticosterone (CORT) or post-natal unpredictable food availability, had long-term effects on pro (IL-1β) and anti-inflammatory (IL-10) cytokine and microglia-dependent gene (CSF1R) expression within HPA axis tissues in a precocial bird, the Japanese quail (Coturnix japonica). Following post-natal stress, we observed increased IL-1β expression in the pituitary gland, reduced IL-10 expression in the amygdala and hypothalamus and reduced CSF1R expression within the hypothalamus and pituitary gland. Post-natal stress disrupted the ratio of IL-1β:IL-10 expression within the hippocampus and hypothalamus. Pre-natal stress only increased IL-1β expression in the pituitary gland. We found no evidence for interactive or cumulative effects across life stages on basal cytokine and glia expression in adulthood. We show that post-natal stress may have a larger impact than elevated pre-natal CORT on basal immunity in HPA axis specific brain regions, with changes in cytokine homeostasis and microglia abundance. These results provide evidence for post-natal programming of a pro-inflammatory neuro-immune phenotype at the expense of reduced microglia, which could have implications for CNS health and subsequent neuro-immune responses.

Stress Triggers Flare of Inflammatory Bowel Disease in Children and Adults

Inflammatory bowel disease (IBD) is an idiopathic inflammatory disease characterized by chronic and relapsing manifestations. It is noteworthy that the prevalence of IBD is gradually increasing in both children and adults. Currently, the pathogenesis of IBD remains to be completely elucidated. IBD is believed to occur through interactions among genetics, environmental factors, and the gut microbiota. However, the relapsing and remitting course of IBD underlines the importance of other modifiers, such as psychological stress. Growing evidence from clinical and experimental studies suggests that stress acts as a promoting or relapsing factor for IBD. Importantly, recent studies have reported an increasing incidence of anxiety or depression in both children and adults with IBD. In this article, we review the mechanisms by which stress affects IBD, such as via impaired intestinal barrier function, disturbance of the gut microbiota, intestinal dysmotility, and immune and neuroendocrine dysfunction. With regard to both children and adults, we provide recent evidence to describe how stress can affect IBD at various stages. Furthermore, we emphasize the importance of mental healing and discuss the value of approaches targeting stress in clinical management to develop enhanced strategies for the prevention and treatment of IBD.

Lifetime-ever pneumonia among pre-school children across China - Associations with pre-natal and post-natal early life environmental factors

BACKGROUND

Biomass burning is associated with childhood pneumonia but few studies exist on other indoor factors.

AIM

To study pneumonia in relation to pre-natal and post-natal exposure among children across China.

METHODS

Children (3-6 y) (n = 39,782) from randomized day care centres in seven cities in China. Information on pneumonia and pre-natal and post-natal exposure to home environment factors were assessed by a parental questionnaire. Life-time outdoor temperature and GDP per capita were assessed on city level. Associations were calculated by multilevel logistic regression adjusting for fourteen co-variates.

RESULTS

Totally 32.0% had ever had pneumonia diagnosed by a physician. Children of farmer mothers (OR = 0.65), with breastfeeding (OR = 0.91) and living in rural (OR = 0.85) or suburban (OR = 0.90) areas had less pneumonia. Buying new furniture one year before conception (OR = 1.11) and after first year of life (OR = 1.10) increased the risk. Redecoration one year before conception (OR = 1.20), during pregnancy (OR = 1.18) and after first year of life (OR = 1.17) increased pneumonia risk. Children with mould (OR = 1.17), window pane condensation (WPC) (OR = 1.20) and mould odour (OR = 1.15) at home at birth only had a higher risk of pneumonia. Similar associations were seen for dampness and mould in the current home. Children in the oldest and newest homes had less pneumonia. Cockroaches (OR = 1.08), mosquitos or flies in the current home (OR = 1.18), an exhaust fan in the bathroom (OR = 1.10) and higher economic development level, measured as GDP per capita on city level (OR 1.11 per 10,000 RMB/year) were associated with childhood pneumonia.

CONCLUSIONS

Perinatal and postnatal exposure to mould, mould odour and window pane condensation at home can be early life risk factors for childhood pneumonia in China. Moreover, pre-natal and post-natal exposure to chemical emissions from new furniture and renovation could increase the risk of childhood pneumonia. Breastfeeding, farm exposure, and living in rural or suburban areas could be protective.

Prenatal stress and the development of psychopathology: Lifestyle behaviors as a fundamental part of the puzzle

Maternal psychological stress, depression, and anxiety during pregnancy (prenatal stress; PNS) are thought to impact fetal development with long-term effects on offspring outcome. These effects would include physical and mental health, including psychopathology. Maternal sleep, diet, and exercise during pregnancy are lifestyle behaviors that are understudied and often solely included in PNS studies as confounders. However, there are indications that these lifestyle behaviors may actually constitute essential mediators between PNS and fetal programming processes. The goal of this theoretical review was to investigate this idea by looking at the evidence for associations between PNS and sleep, diet, and exercise, and by piecing together the information on potential underlying mechanisms and causal pathways through which these factors may affect the offspring. The analysis of the literature led to the conclusion that sleep, diet, and exercise during pregnancy, may have fundamental roles as mediators between PNS and maternal pregnancy physiology. By integrating these lifestyle behaviors into models of prenatal programming of development, a qualitatively higher and more comprehensive understanding of the prenatal origins of psychopathology can be obtained. The review finalizes by discussing some of the present challenges facing the field of PNS and offspring programming, and offering solutions for future research.

Early life stress in mice is a suitable model for Irritable Bowel Syndrome but does not predispose to colitis nor increase susceptibility to enteric infections

Neonatal period is characterized by an immature intestinal barrier. Scattered evidence suggests that early life stressful events induce long lasting alterations of intestinal homeostasis mimicking Irritable Bowel Syndrome (IBS). Those observations highlighting defect of intestinal barrier by early life stress questioned its potential role as a risk factor for gastrointestinal disorders such as colitis and infections. In this study, we aimed to analyze if maternal separation (MS) in mice mimicks IBS main features. We next addressed whether MS could trigger or exacerbate colitis in genetically predisposed mice and/or enhance susceptibility to gastrointestinal infections in wild type mice. MS induced main features of IBS in adult wild type male mice i.e. intestinal hyperpermeability, visceral hypersensitivity, microbiota dysbiosis, bile acid malabsorption and low grade inflammation in intestine associated with a defect of Paneth cells and the ILC3 population. This breach in mucosal barrier functions in adults was associated with a systemic IgG response against commensal E. coli and increased IFNγ secretion by splenocytes. However, in IL10^-/- mice, MS did not trigger nor worsen colitis. Furthermore, wild type mice submitted to MS did not show increase susceptibility to gastrointestinal infections (S. Typhimurium, L. monocytogenes or T. gondii) compared to controls. Altogether, our results identify MS in mice as a good experimental model for IBS mimicking all the main features. In addition, early life stress, even though it has long lasting consequences on intestinal homeostasis, does not constitute a facilitating factor to colitis in predisposed individuals nor to gastrointestinal infections in wild type mice.

Neuroimmune Interactions: From the Brain to the Immune System and Vice Versa

Because of the compartmentalization of disciplines that shaped the academic landscape of biology and biomedical sciences in the past, physiological systems have long been studied in isolation from each other. This has particularly been the case for the immune system. As a consequence of its ties with pathology and microbiology, immunology as a discipline has largely grown independently of physiology. Accordingly, it has taken a long time for immunologists to accept the concept that the immune system is not self-regulated but functions in close association with the nervous system. These associations are present at different levels of organization. At the local level, there is clear evidence for the production and use of immune factors by the central nervous system and for the production and use of neuroendocrine mediators by the immune system. Short-range interactions between immune cells and peripheral nerve endings innervating immune organs allow the immune system to recruit local neuronal elements for fine tuning of the immune response. Reciprocally, immune cells and mediators play a regulatory role in the nervous system and participate in the elimination and plasticity of synapses during development as well as in synaptic plasticity at adulthood. At the whole organism level, long-range interactions between immune cells and the central nervous system allow the immune system to engage the rest of the body in the fight against infection from pathogenic microorganisms and permit the nervous system to regulate immune functioning. Alterations in communication pathways between the immune system and the nervous system can account for many pathological conditions that were initially attributed to strict organ dysfunction. This applies in particular to psychiatric disorders and several immune-mediated diseases. This review will show how our understanding of this balance between long-range and short-range interactions between the immune system and the central nervous system has evolved over time, since the first demonstrations of immune influences on brain functions. The necessary complementarity of these two modes of communication will then be discussed. Finally, a few examples will illustrate how dysfunction in these communication pathways results in what was formerly considered in psychiatry and immunology to be strict organ pathologies.

Zika Virus as a Possible Risk Factor for Autism Spectrum Disorder: Neuroimmunological Aspects

The recent outbreak of the Zika virus (ZIKV) and the discovery that perinatal Zika exposure can lead to the Congenital Zika Syndrome has promoted a call for prevention measures. Due to the increased number of babies born with microcephaly, structural brain abnormalities, and neurological alterations in regions affected by ZIKV, investigations were carried out in order to better understand this process. The maternal immune system directly influences the fetal central nervous system, and complications during pregnancy have been associated with neurodevelopmental disorders. Autism spectrum disorder (ASD), a neurodevelopmental disorder commonly manifested in the first years of life, is a disease with multifactorial etiology and is manifested typically by social and communication impairments, as well as stereotyped behaviors. Brain abnormalities, including both anatomically and functionally, can be observed in this disorder, suggesting delays in neuronal maturation and altered brain connectivity. It is known that some viral congenital infections, such as rubella, and cytomegalovirus can interfere with brain development, being associated with brain calcification, microcephaly, and ASD. Here, we reviewed a range of studies evaluating the aspects concerning brain development, immunological status during pregnancy, and neuroimmunomodulation in congenital viral infections, and we discuss if the fetal brain infection caused by ZIKV could predispose to ASD. Finally, we suggest a mechanism encompassing neurological and immunological pathways that could play a role in the development of ASD in infants after ZIKV infection in pregnancy.

Maternal care modulates the febrile response to lipopolysaccharide through differences in glucocorticoid receptor sensitivity in the rat

Early life adversity increases the risk for later infection. The febrile response is a potent mechanism to combat infection. We found that variations in maternal care influence the febrile response to 50µg/kg lipopolysaccharide (LPS) challenge in adult male rats. Offspring from low-licking/grooming (LG) mothers had an increased febrile response compared to offspring from high-LG mothers challenged with LPS. Low-LG offspring had reduced plasma IL-6 at one and two hours post challenge compared to high-LG offspring. IL-6 gene expression in the anterior hypothalamus was induced following LPS challenge in low-LG offspring but not in high-LG offspring at two hours post challenge. Occupancy of the transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) to the IL-6 promoter region in the anterior hypothalamus was greater in low-LG offspring treated with LPS than in high-LG offspring. These findings suggest greater activation of thermoregulatory neurons in the anterior hypothalamus of low-LG compared to high-LG offspring following LPS challenge. Low-LG offspring had greater plasma corticosterone levels following LPS challenge and they had enhanced glucocorticoid receptors (GR) in the spleen compared to high-LG offspring. Enhanced glucocorticoids and glucocorticoid receptor sensitivity associated with reduced IL-6 induction early post challenge in low-LG offspring. Challenge with RU-486 prior to LPS challenge eliminated differences in the febrile response between offspring of high and low-LG mothers. Individual differences in GR sensitivity may modulate differences in the febrile response to LPS challenge, exerting a long-term influence on the capacity to recover from infection.

Biological embedding of childhood adversity: from physiological mechanisms to clinical implications

BACKGROUND

Adverse psychosocial exposures in early life, namely experiences such as child maltreatment, caregiver stress or depression, and domestic or community violence, have been associated in epidemiological studies with increased lifetime risk of adverse outcomes, including diabetes, heart disease, cancers, and psychiatric illnesses. Additional work has shed light on the potential molecular mechanisms by which early adversity becomes "biologically embedded" in altered physiology across body systems. This review surveys evidence on such mechanisms and calls on researchers, clinicians, policymakers, and other practitioners to act upon evidence.

OBSERVATIONS

Childhood psychosocial adversity has wide-ranging effects on neural, endocrine, immune, and metabolic physiology. Molecular mechanisms broadly implicate disruption of central neural networks, neuroendocrine stress dysregulation, and chronic inflammation, among other changes. Physiological disruption predisposes individuals to common diseases across the life course.

CONCLUSIONS

Reviewed evidence has important implications for clinical practice, biomedical research, and work across other sectors relevant to public health and child wellbeing. Warranted changes include increased clinical screening for exposures among children and adults, scale-up of effective interventions, policy advocacy, and ongoing research to develop new evidence-based response strategies.

Common cold among pre-school children in China - associations with ambient PM10 and dampness, mould, cats, dogs, rats and cockroaches in the home environment

BACKGROUND

There is some evidence that dampness, mould and cockroaches can increase the risk of respiratory infections in children but few studies exist from China on this topic. Aim To study associations between domestic early life exposure to biological indoor factors (dampness, mould, cats, dogs, rats, cockroaches), cleaning habits and common cold among pre-school children across China.

METHODS

Children aged 3-6years (n=39,782) were recruited from randomly selected day care centres in seven cities in China. Data on common cold and prenatal and postnatal exposure to dampness, mould, windowpane condensation in wintertime (WPC), cats, dogs, cockroaches and rats were assessed by a parentally administered questionnaire. Data on annual ambient temperature and PM₁₀ was assessed on city level. Associations between high frequency (>5 colds per year) and long duration (≥2weeks) of common colds in the past year and exposure were calculated by multilevel logistic regression.

RESULTS

A total of 9.2% had a high frequency and 11.9% had long duration of common cold. Exposure to mould (OR=1.38, 95% CI 1.24-1.53) and WPC (OR 1.23, 95%CI 1.13-1.33) at birth was associated with frequent common cold. Exposure to dogs at birth was associated with long duration of common cold. (OR=1.22, 95% CI 1.06-1.41). Exposure to mould (OR=1.36, 95% CI 1.22-1.54), WPC (OR=1.27, 95%CI 1.17-1.39) and water leakage (OR 1.34, 95% CI 1.20-1.49) in the current home was associated with frequent common cold. Presence of cockroaches were positively (OR=1.12, 95% CI 1.02-1.24) and presence of rats (OR=0.86, 95% CI 0.77-0.96) negatively associated with high frequency of common cold. Daily cleaning was negatively associated with frequent common cold (OR=0.89, 95% CI 0.81-0.97). Similar associations for mould, WPC, cockroaches and rats were found for long duration. Ambient PM₁₀ (OR=1.21, 95% CI 1.21-1.35 per 10μg/m³) and temperature (OR=1.13, 95% CI 1.06-1.35 °C) on city level were associated with high frequency of common cold. Associations between cat keeping and high frequency of common cold were found only in southern China. Associations with cockroaches were stronger in northern China. Associations with dampness and mould were the same in the north and south.

CONCLUSIONS

Indoor mould, water damage, windowpane condensation, cockroaches and keeping cats or dogs as pets can be risk factors for common cold while daily cleaning can be protective factor. PM₁₀ and a warmer climate zone can be other risk factors for common cold.

Early-life stress origins of gastrointestinal disease: animal models, intestinal pathophysiology, and translational implications

Early-life stress and adversity are major risk factors in the onset and severity of gastrointestinal (GI) disease in humans later in life. The mechanisms by which early-life stress leads to increased GI disease susceptibility in adult life remain poorly understood. Animal models of early-life stress have provided a foundation from which to gain a more fundamental understanding of this important GI disease paradigm. This review focuses on animal models of early-life stress-induced GI disease, with a specific emphasis on translational aspects of each model to specific human GI disease states. Early postnatal development of major GI systems and the consequences of stress on their development are discussed in detail. Relevant translational differences between species and models are highlighted.

Prenatal exposure to selective serotonin reuptake inhibitors (SSRI) increases aggression and modulates maternal behavior in offspring mice

Selective serotonin reuptake inhibitors (SSRI) are commonly prescribed antidepressant drugs in pregnant women. SSRIs cross the placental barrier and affect serotonergic neurotransmission in the fetus. Although no gross SSRI-related teratogenic effects were reported, infants born following prenatal exposure to SSRIs are at higher risk for various developmental abnormalities. The aim of this study was to examine the effects of prenatal SSRI on social and maternal behavior in mice. To this end, pregnant female dams were exposed to saline or fluoxetine (FLX) throughout pregnancy, and the behavior of the offspring was examined. The results indicate that in utero FLX increased aggression in adult males and delayed emergence of maternal behavior in adult females. Social exploration and recognition memory were not affected by prenatal FLX exposure. These findings support the notion that alterations in the development of serotonergic pathways following prenatal exposure to SSRIs are associated with changes in social and maternal behavior throughout life.