Alterations in inflammatory, antiviral and regulatory cytokine responses in peripheral blood mononuclear cells from pregnant women with asthma

Inflammatory and antiviral responses to influenza A virus infection are dysregulated in pregnant mice with allergic airway disease

Influenza A virus (IAV) infections are increased during pregnancy especially with asthma as a comorbidity, leading to asthma exacerbations, secondary bacterial infections, intensive care unit admissions, and mortality. We aimed to define the processes involved in increased susceptibility and severity of IAV infections during pregnancy, especially with asthma. We sensitized mice to house dust mite (HDM), induced pregnancy, and challenged with HDM to induce allergic airway disease (AAD). At midpregnancy, we induced IAV infection. We assessed viral titers, airway inflammation, lung antiviral responses, mucus hypersecretion, and airway hyperresponsiveness (AHR). During early IAV infection, pregnant mice with AAD had increased mRNA expression of the inflammatory markers Il13 and IL17 and reduced mRNA expression of the neutrophil chemoattractant marker Kc. These mice had increased mucous hyperplasia and increased AHR. miR155, miR574, miR223, and miR1187 were also reduced during early infection, as was mRNA expression of the antiviral β-defensins, Bd1, Bd2, and Spd and IFNs, Ifnα, Ifnβ, and Ifnλ. During late infection, Il17 was still increased as was eosinophil infiltration in the lungs. mRNA expression of Kc was reduced, as was neutrophil infiltration and mRNA expression of the antiviral markers Ifnβ, Ifnλ, and Ifnγ and Ip10, Tlr3, Tlr9, Pkr, and Mx1. Mucous hyperplasia was still significantly increased as was AHR. Early phase IAV infection in pregnancy with asthma heightens underlying inflammatory asthmatic phenotype and reduces antiviral responses.NEW & NOTEWORTHY Influenza A virus (IAV) infection during pregnancy with asthma is a major health concern leading to increased morbidity for both mother and baby. Using murine models, we show that IAV infection in pregnancy with allergic airway disease is associated with impaired global antiviral and antimicrobial responses, increased lung inflammation, mucus hypersecretion, and airway hyperresponsiveness (AHR). Targeting specific β-defensins or microRNAs (miRNAs) may prove useful in future treatments for IAV infection during pregnancy.

Asthma in pregnancy

Background: Asthma is a frequent and potentially life-threatening disease that complicates many pregnancies. There are extensive data with regard to the diagnosis and treatment of asthma during pregnancy. Medical providers require an up-to-date summary of the critical aspects of asthma management during pregnancy. Objective: This review aimed to summarize the available data from clinical trials, cohort studies, expert opinions, and guideline recommendations with regard to asthma in pregnancy. Methods: A search through PubMed was conducted by using keywords previously mentioned and MeSH (Medical Subject Headings) terminology. Clinical trials, observational studies, expert opinions, guidelines, and other reviews were included. The quality of the studies was assessed, and data were extracted and summarized. Results: Asthma worsens in ∼40% of pregnant women, which can be associated with maternal and fetal complications. Physiologic changes in the respiratory, cardiovascular, and immune systems during pregnancy play a critical role in the manifestations of asthma. The diagnosis and the treatment of asthma are similar to that of patients who are not pregnant. Nonetheless, concern for fetal malformations, preterm birth, and low birth weight must be considered when managing pregnant patients with asthma. Importantly, cornerstones of the pharmacotherapy of asthma seem to be safe during pregnancy. Conclusion: Asthma in pregnancy is associated with adverse outcomes. Roadblocks to management include associated comorbidities, medication nonadherence, atopy, lack of education, and smoking habits. These need to be acknowledged and addressed for successful asthma management during pregnancy.

The obstetric aspects of maternal asthma

Asthma is the commonest chronic medical condition encountered in pregnancy. Poor asthma control and exacerbations are frequently encountered due to treatment non-adherence, pregnancy-related aggravating factors such as increased susceptibility to viral infections, and comorbidities that are commonly associated. Asthma-related inflammatory reactions and placental effects, the effect of medications, and respiratory symptoms and hypoxia are probably to interact to result in an increased adverse obstetric outcomes including miscarriage, foetal congenital anomalies, pregnancy hypertensive disorders, gestational diabetes, preterm labour and birth, antepartum haemorrhage, low birthweight and foetal growth restriction (FGR), caesarean delivery, postpartum haemorrhage (PPH), maternal intensive care admission, and even mortality, while the offspring also has increased long-term morbidity. Interdisciplinary management with frequent assessment by symptoms, spirometry, and biomarkers, together with removal of risk factors such as smoking and appropriate instigation of treatment including short courses of systemic corticosteroid, could ensure optimal and tailored treatment to control symptoms, prevent exacerbations, and ultimately enhancing maternal and perinatal outcomes.

Cord blood group 2 innate lymphoid cells are associated with lung function at 6 weeks of age

Objective

Offspring born to mothers with asthma in pregnancy are known to have lower lung function which tracks with age. Human group 2 innate lymphoid cells (ILC2) accumulate in foetal lungs, at 10‐fold higher levels compared to adult lungs. However, there are no data on foetal ILC2 numbers and the association with respiratory health outcomes such as lung function in early life. We aimed to investigate cord blood immune cell populations from babies born to mothers with asthma in pregnancy.

Methods

Cord blood from babies born to asthmatic mothers was collected, and cells were stained in whole cord blood. Analyses were done using traditional gating approaches and computational methodologies (t‐distributed stochastic neighbour embedding and PhenoGraph algorithms). At 6 weeks of age, the time to peak tidal expiratory flow as a percentage of total expiratory flow time (tPTEF/tE%) was determined as well as Lung Clearance Index (LCI), during quiet natural sleep.

Results

Of 110 eligible infants (March 2017 to November 2019), 91 were successfully immunophenotyped (82.7%). Lung function was attempted in 61 infants (67.0%), and 43 of those infants (70.5% of attempted) had technically acceptable tPTEF/tE% measurements. Thirty‐four infants (55.7% of attempted) had acceptable LCI measurements. Foetal ILC2 numbers with increased expression of chemoattractant receptor‐homologous molecule (CRTh2), characterised by two distinct analysis methodologies, were associated with poorer infant lung function at 6 weeks of age.”

Conclusion

Foetal immune responses may be a surrogate variable for or directly influence lung function outcomes in early life.

Single-cell characterization of a model of poly I:C-stimulated peripheral blood mononuclear cells in severe asthma

Background

Asthma has been associated with impaired interferon response. Multiple cell types have been implicated in such response impairment and may be responsible for asthma immunopathology. However, existing models to study the immune response in asthma are limited by bulk profiling of cells. Our objective was to Characterize a model of peripheral blood mononuclear cells (PBMCs) of patients with severe asthma (SA) and its response to the TLR3 agonist Poly I:C using two single-cell methods.

Methods

Two complementary single-cell methods, DropSeq for single-cell RNA sequencing (scRNA-Seq) and mass cytometry (CyTOF), were used to profile PBMCs of SA patients and healthy controls (HC). Poly I:C-stimulated and unstimulated cells were analyzed in this study.

Results

PBMCs (n = 9414) from five SA (n = 6099) and three HC (n = 3315) were profiled using scRNA-Seq. Six main cell subsets, namely CD4 + T cells, CD8 + T cells, natural killer (NK) cells, B cells, dendritic cells (DCs), and monocytes, were identified. CD4 + T cells were the main cell type in SA and demonstrated a pro-inflammatory profile characterized by increased JAK1 expression. Following Poly I:C stimulation, PBMCs from SA had a robust induction of interferon pathways compared with HC. CyTOF profiling of Poly I:C stimulated and unstimulated PBMCs (n = 160,000) from the same individuals (SA = 5; HC = 3) demonstrated higher CD8 + and CD8 + effector T cells in SA at baseline, followed by a decrease of CD8 + effector T cells after poly I:C stimulation.

Conclusions

Single-cell profiling of an in vitro model using PBMCs in patients with SA identified activation of pro-inflammatory pathways at baseline and strong response to Poly I:C, as well as quantitative changes in CD8 + effector cells. Thus, transcriptomic and cell quantitative changes are associated with immune cell heterogeneity in this model to evaluate interferon responses in severe asthma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01709-9.

Vaccination of pregnant women against influenza: what is the optimal timing?

Pregnant women and young infants are at increased risk for severe influenza and its complications. Influenza vaccination during pregnancy is increasingly implemented as a strategy aiming to protect the pregnant woman, the fetus and the young infant. In clinical practice, the achievement of satisfactory protection for the pregnant woman without compromising the protection of her infant during the first months of life remains a challenge. Determinants that are implicated in the optimal timing of influenza vaccination in pregnancy include influenza season, trimester of pregnancy, maternal host factors and infant factors. This article addresses influenza vaccination in pregnancy and presents recent published evidence on issues that affect the optimization of the timing of maternal vaccination.

Impact of influenza virus during pregnancy: from disease severity to vaccine efficacy

Pregnant women are among the individuals at the highest risk for severe influenza virus infection. Infection of the mother during pregnancy increases the probability of adverse fetal outcomes such as small for gestational age, preterm birth and fetal death. Animal models of syngeneic and allogeneic mating can recapitulate the increased disease severity observed in pregnant women and are used to define the mechanism(s) of that increased severity. This review focuses on influenza A virus pathogenesis, the unique immunological landscape during pregnancy, the impact of maternal influenza virus infection on the fetus and the immune responses at the maternal–fetal interface. Finally, we summarize the importance of immunization and antiviral treatment in this population and highlight issues that warrant further investigation.

Chlamydia pneumoniae Influence on Cytokine Production in Steroid-Resistant and Steroid-Sensitive Asthmatics

Medications for asthma management consisting of inhaled corticosteroids act by controlling symptoms. However, some patients do not respond to steroid treatment due to immunological factors at the cytokine level. Chlamydia pneumoniae (C. pneumoniae) infection is strongly implicated in asthma pathogenesis, causing altered immune responses. We investigated the association of C. pneumoniae serostatus with the production of certain cytokines by peripheral blood mononuclear cells (PBMCs) of steroid-resistant and -sensitive asthmatic patients. Our most important findings are the following: In the case of C. pneumoniae seropositive patients we detected pronounced spontaneous interleukin (IL)-10 secretion and, in the case of steroid-resistant patients, IL-10 secretion was at a significantly higher level as compared with in-sensitive patients (p < 0.01). Furthermore, steroid-resistant seropositive patients produced a significantly higher level of IL-10 spontaneously and under antigen stimulation as compared with steroid-resistant seronegative individuals (p < 0.05). Concerning spontaneous TNF-α secretion by C. pneumoniae seropositive asthmatics, we observed that steroid-resistant patients produced significantly more of this cytokine than steroid-sensitive patients. In the steroid-resistant patients’ sera, a remarkably high MMP-9 concentration was associated with C. pneumoniae seronegativity. Our study revealed that the differences in the cytokine production in steroid-sensitive and -resistant asthmatic patients can be influenced by their C. pneumoniae serostatus.

The role of Th17 cells in the pathophysiology of pregnancy and perinatal mood and anxiety disorders

T cells play a key role in adaptive immune responses, and shifts among T cell classes occur in normal pregnancy. There is evidence for the role of T_H17 cells and dysregulation of the T_H17/T_reg cell balance in morbidities and autoimmune diseases during pregnancy. Because T_H17 responses may play a role in depression and anxiety outside of pregnancy, we hypothesize that T_H17 responses and the balance of T_H17/T_reg activity may also contribute to the development of depression and anxiety during pregnancy. To explore this hypothesis, this review has three main aims: 1) to evaluate systematically the role of T_H17 cells and cytokines during pregnancy; 2) to compare changes in the ratio of T_H17/T_reg cells during pregnancy morbidities with the changes that occur in depression and anxiety outside of pregnancy; and 3) to provide a basis for further research on T_H17 cells in perinatal mood and anxiety disorders, with an eye toward the development of novel therapeutics. We also review the limited literature concerning perinatal mood and anxiety disorders, and hypothesize about the potential role of T_H17 cells in these illnesses. Understanding the pathophysiology of perinatal mood and anxiety disorders will aid development of novel therapeutics that address immunological mechanisms, in addition to the serotonin system, which are targetable molecules in treating depression and anxiety during pregnancy.

Pregnancy modulates the allergen-induced cytokine production differently in allergic and non-allergic women

BACKGROUND

The immunological environment during pregnancy may differ between allergic and non-allergic women. This study investigates the effect of maternal allergy on the allergen-induced cytokine and chemokine levels and whether pregnancy modulates these immune responses differently in allergic and non-allergic women.

METHODS

The birch-, cat-, phytohemagglutinin- and tetanus toxoid-induced interferon-γ (IFN-γ), interleukin (IL)-4, IL-5, IL-10, IL-13, the T-helper 1 (Th1)-associated chemokine CXCL10 and the Th2-associated chemokine CCL17 levels were quantified in 20 women with allergic symptoms (sensitized, n = 13) and 36 women without allergic symptoms (non-sensitized, n = 30) at gestational weeks 10-12, 15-16, 25, 35 and 2 and 12 months post-partum.

RESULTS

Birch-, but not cat-induced, IL-5, IL-13 and CCL17 levels were increased during pregnancy as compared to post-partum in the sensitized women with allergic symptoms. In contrast, cat-, but not birch-induced, IL-5 and IL-13 levels were increased during pregnancy as compared to post-partum in the non-sensitized women without allergic symptoms. Furthermore, IFN-γ secretion was increased in the first and decreased in the second and third trimesters in response to birch and decreased in the third trimester in response to cat as compared to post-partum in the non-sensitized women without allergic symptoms. Increased allergen-induced IL-4, IL-5 and IL-13 levels were associated with allergic symptoms and sensitization.

CONCLUSIONS

Pregnancy had a clear effect on the allergen-induced IL-5, IL-13, CCL17, IFN-γ and CXCL10 production, with distinct enhanced Th2-responses to birch in the allergic group and to cat in the non-allergic group.

Clinical efficacy of recombinant human latrophilin 3 antibody in the treatment of pediatric asthma

Pediatric asthma is a chronic pulmonary inflammatory disease featuring hypersecretion of mucus and inflammation in the airway, resulting in dysfunction of the airway smooth muscle. Previous evidence demonstrated that latrophilins, a novel family of receptors, present a beneficial effect on airway smooth muscle cells. In the present study, the therapeutic effects of recombinant human latrophilin 3 (rhLPHN3) antibody (Ab) in patients with pediatric asthma were investigated, and the molecular mechanism underlying the function of LPHN3 in the treatment of asthma in clinical practice was examined. A total of 342 pediatric asthma cases were recruited and randomly divided into three groups, receiving treatment with rhLPHN3 Ab (n=134), salbutamol (n=108) or montelukast (n=100) by nasal aerosolization. Each group received the respective clinically tested dose for 16 weeks. Inflammatory factors interleukin (IL)-10, IL-17, IL-4, matrix metallopeptidase-9 (MMP-9), interferon-γ (IFN-γ) and transforming growth factor-β (TGF-β) levels in peripheral blood mononuclear cells were analyzed prior to and post treatment. The clinical outcomes revealed that pathological alterations were significantly improved following treatment with rhLPHN3 Ab for patients with pediatric asthma when compared with those receiving salbutamol and montelukast. It was also observed that rhLPHN3 Ab downregulated the plasma concentration levels of IL-10, IL-17, IL-4 and MMP-9, and upregulated IFN-γ and TGF-β levels in the three groups. In addition, clinical data demonstrated that rhLPHN3 Ab significantly promoted E-selectin and mucin 5AC expression, as well as improved the activation of nuclear factor (NF)-κB p65 DNA binding activity and the phosphorylation levels of protein kinase A. Furthermore, rhLPHN3 Ab markedly improved adhesion and proliferation of airway smooth muscle cells, which led to promotion of the contraction of these cells. In conclusion, these clinical data suggest that rhLPHN3 Ab serves an important role in the inhibition of inflammatory mediators through downregulation of NF-κB signaling pathway, which contributes to airway remodeling and bronchodilation in patients with pediatric asthma.

Maternal complications and the management of asthma in pregnancy

Pregnancy is a unique state requiring alterations in maternal physiology to accommodate the growing fetus. Whilst the maternal immune system is normally well adept at performing this task, the presence of immune disorders, such as asthma, often lead to pregnancy-related complications affecting both mother and baby. Australia has a high prevalence of asthma; with approximately 12% of pregnant women reported to have current asthma. Poor control of asthma is of far greater risk than the use of asthma medications. Being able to identify complications associated with asthma during pregnancy is of great importance in providing appropriate asthma management and medical care to these pregnant women, which may have lifelong consequences for their offspring.

Bioenergetic analysis of human peripheral blood mononuclear cells

Leucocytes respond rapidly to pathogenic and other insults, with responses ranging from cytokine production to migration and phagocytosis. These are bioenergetically expensive, and increased glycolytic flux provides adenosine triphosphate (ATP) rapidly to support these essential functions. However, much of this work is from animal studies. To understand more clearly the relative role of glycolysis and oxidative phosphorylation in human leucocytes, especially their utility in a translational research setting, we undertook a study of human peripheral blood mononuclear cells (MNCs) bioenergetics. Glycolysis was essential during lipopolysaccharide (LPS)-mediated interleukin (IL)-1β, IL-6 and tumour necrosis factor (TNF)-α production, as 2-deoxy-D-glucose decreased significantly the output of all three cytokines. After optimizing cell numbers and the concentrations of all activators and inhibitors, oxidative phosphorylation and glycolysis profiles of fresh and cryopreserved/resuscitated MNCs were determined to explore the utility of MNCs for determining the bioenergetics health profile in multiple clinical settings. While the LPS-induced cytokine response did not differ significantly between fresh and resuscitated cells from the same donors, cryopreservation/resuscitation significantly affected mainly some measures of oxidative phosphorylation, but also glycolysis. Bioenergetics analysis of human MNCs provides a quick, effective means to measure the bioenergetics health index of many individuals, but cryopreserved cells are not suitable for such an analysis. The translational utility of this approach was tested by comparing MNCs of pregnant and non-pregnant women to reveal increased bioenergetics health index with pregnancy but significantly reduced basal glycolysis and glycolytic capacity. More detailed analysis of discrete leucocyte populations would be required to understand the relative roles of glycolysis and oxidative phosphorylation during inflammation and other immune responses.

TaqMan real time RT-PCR assays for detecting ferret innate and adaptive immune responses

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The ferret model is used to study human disease and physiology.

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TaqMan realtime RT-PCR assays for ferret cytokine and chemokine mRNA were developed.

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Cytokine and chemokine patterns in ferret cells were similar to other mammals.

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A comprehensive panel of mRNAs can be measured in samples of limited quantity.

The ferret is an excellent model for many human infectious diseases including influenza, SARS-CoV, henipavirus and pneumococcal infections. The ferret is also used to study cystic fibrosis and various cancers, as well as reproductive biology and physiology. However, the range of reagents available to measure the ferret immune response is very limited. To address this deficiency, high-throughput real time RT-PCR TaqMan assays were developed to measure the expression of fifteen immune mediators associated with the innate and adaptive immune responses (IFNα, IFNβ, IFNγ, IL1α, IL1β, IL2, IL4, IL6, IL8, IL10, IL12p40, IL17, Granzyme A, MCP1, TNFα), as well as four endogenous housekeeping genes (ATF4, HPRT, GAPDH, L32). These assays have been optimized to maximize reaction efficiency, reduce the amount of sample required (down to 1 ng RNA per real time RT-PCR reaction) and to select the most appropriate housekeeping genes. Using these assays, the expression of each of the tested genes could be detected in ferret lymph node cells stimulated with mitogens or infected with influenza virus in vitro. These new tools will allow a more comprehensive analysis of the ferret immune responses following infection or in other disease states.

Respiratory viral infections in pregnant women with asthma are associated with wheezing in the first 12 months of life

BACKGROUND

There are few studies investigating the relationship between respiratory viral infection in pregnancy and asthma in the offspring, and none among mothers with asthma. Infants of mothers with asthma are more likely to wheeze and have a higher risk of developing asthma than infants of non-asthmatic mothers.

METHODS

A prospective cohort study of viral infection in pregnancy was conducted between 2007 and 2009, and a subgroup of infants of mothers with asthma was followed up at 6 and 12 months of age. During common colds, nasal and throat swabs were collected from mothers and respiratory viruses detected by polymerase chain reaction. Respiratory health of infants was assessed by parent-completed questionnaire.

RESULTS

Twelve-month-old infants whose mothers had confirmed viral infections in pregnancy (n = 26) reported more frequent wheeze (40% had 4-12 wheeze attacks compared with 0%), sleep disturbed by wheeze (1 night per week or more in 60% vs. 11%), beta agonist treatment for wheeze (27% vs. 0%), prolonged colds (2 wk or longer 31% vs. 0%), more eczema (40% vs. 6.3%), and parent-perceived asthma (32% vs. 0%), compared with infants whose mothers had common colds without laboratory-confirmed viral infection (n = 16).

CONCLUSIONS

This study demonstrates a relationship between maternal respiratory viral infection in pregnancy and wheezing illness in infants of mothers with asthma. Viral infections are the most common cause of asthma exacerbations in pregnancy, and infants of asthmatic mothers are at increased risk of asthma themselves. Further research is needed to elucidate the mechanisms involved.

The risk of maternal and placental complications in pregnant women with asthma: a systematic review and meta-analysis

OBJECTIVE

To investigate if maternal asthma is associated with an increased risk of maternal and placental complications in pregnancy.

METHODS

Electronic databases were searched for the following terms: (asthma or wheeze) and (pregnan* or perinat* or obstet*). Cohort studies published between January 1975 and March 2012 were considered for inclusion. Forty publications met the inclusion criteria, reporting at least one maternal or placental complication in pregnant women with and without asthma. Relative risk (RR) with 95% confidence intervals (CIs) was calculated.

RESULTS

Maternal asthma was associated with a significantly increased risk of cesarean section (RR = 1.31, 95%CI = [1.22-1.39]), gestational diabetes (RR = 1.39, 95%CI = [1.17-1.66]), hemorrhage (antepartum: RR = 1.25, 95%CI = [1.10-1.42]; postpartum: RR = 1.29, 95%CI = [1.18-1.41]), placenta previa (RR = 1.23, 95%CI = [1.07-1.40]), placental abruption (RR = 1.29, 95%CI = [1.14-1.47]) and premature rupture of membranes (RR = 1.21, 95%CI = 1.07-1.37). Moderate to severe asthma significantly increased the risk of cesarean section (RR = 1.19, 95%CI = [1.09-1.31]) and gestational diabetes (RR = 1.19, 95%CI = [1.06-1.33]) compared to mild asthma. Bronchodilator use was associated with a significantly lowered risk of gestational diabetes (RR = 0.64, 95%CI = [0.57-0.72]).

CONCLUSIONS

Pregnant women with asthma are at increased risk of maternal and placental complications, and women with moderate/severe asthma may be at particular risk. Further studies are required to elucidate whether adequate control of asthma during pregnancy reduces these risks.