T-helper type 2 polarization among asthmatics during and following pregnancy

Maternal exposure to farming environment protects offspring against allergic diseases by modulating the neonatal TLR-Tregs-Th axis

Background

As the development of urbanization in China, the morbidity of allergic disease rise up prominently even in children, which may be partially associated with the excessively clean environment. It has been reported that common microorganism in rural environment shows protective effects on allergic disease by modulating TLRs-Tregs/Th cell axis. But the mechanism of this protection still needs to be elucidated in detail. We investigated the effects of maternal exposure to farming environment on the neonatal innate immune system, especially on the TLR-Treg-Th (Th1, Th2, Th9, and Th17) axis, in the Jilin province of China.

Methods

Eighty-four non-farming and 42 farming pregnant women were recruited. Endotoxins and glucans in dust from the living rooms of the pregnant mothers were measured. Cord blood mononuclear cells were challenged with phytohemagglutinin, lipopolysaccharide, or peptidoglycan. Proliferative response of lymphocyte was measured by 3H-TdR incorporation methods, CD4 + CD25 + FOXP3 + T cells percentage was assessed with flow cytometry, Tregs specific genes (FOXP3, LAG3, GITR, CTLA-4 and TGF-β) and TLR2, TLR4 genes expression were detected by RT-PCR, specific cytokines of Th1, Th2, Th9, Th17 and Tregs were measured with flow cytometer, suppressive capacity of Tregs was tested by culturing with effector cells in vitro, and TLR2/4 gene polymorphism was detected.

Results

Higher endotoxin content was observed in the living rooms of the farming mothers. Compared with that in the non-farming group, in farming neonatal CBMCs, lymphocyte proliferation declined; the IFN-γ/IL-13 ratio increased; and the quantity of Tregs and gene expression of FOXP3, GITR, CTLA4 and TLR2 increased significantly (P < 0.05). Isolated Tregs suppressed the proliferation of effector T cells and IL-13 production more strongly in vitro (P = 0.04, 0.03, respectively), and the TLR2 polymorphism affected FOXP3 expression and IFN-γ and IL-13 production.

Conclusions

Maternal exposure to farming affected the quantity and function of neonatal Tregs upon stimulation with PPG and LPS, which partly contributed to reducing the risk for allergic diseases in the offspring. The results of our study will lay the theoretical foundation for allergic disease prevention in early life.

Electronic supplementary material

The online version of this article (10.1186/s13601-018-0220-0) contains supplementary material, which is available to authorized users.

IP-10 and MIG are compartmentalized at the site of disease during pleural and meningeal tuberculosis and are decreased after antituberculosis treatment

The diagnosis of active tuberculosis (TB) disease remains a challenge, especially in high-burden settings. Cytokines and chemokines are important in the pathogenesis of TB. Here we investigate the usefulness of circulating and compartmentalized cytokines/chemokines for diagnosis of TB. The levels of multiple cytokines/chemokines in plasma, pleural fluid (PF), and cerebrospinal fluid (CSF) were determined by Luminex liquid array-based multiplexed immunoassays. Three of 26 cytokines/chemokines in plasma were significantly different between TB and latent tuberculosis infection (LTBI). Among them, IP-10 and MIG had the highest diagnostic values, with an area under the receiver operating characteristic curve (ROC AUC) of 0.92 for IP-10 and 0.86 for MIG for distinguishing TB from LTBI. However, IP-10 and MIG levels in plasma were not different between TB and non-TB lung disease. In contrast, compartmentalized IP-10 and MIG in the PF and CSF showed promising diagnostic values in discriminating TB and non-TB pleural effusion (AUC = 0.87 for IP-10 and 0.93 for MIG), as well as TB meningitis and non-TB meningitis (AUC = 0.9 for IP-10 and 0.95 for MIG). A longitudinal study showed that the plasma levels of IP-10, MIG, granulocyte colony-stimulating factor (G-CSF), and gamma interferon (IFN-γ) decreased, while the levels of MCP-1/CCL2 and eotaxin-1/CCL11 increased, after successful treatment of TB. Our findings provide a practical methodology for discriminating active TB from LTBI by sequential IFN-γ release assays (IGRAs) and plasma IP-10 testing, while increased IP-10 and MIG at the site of infection (PF or CSF) can be used as a marker for distinguishing pleural effusion and meningitis caused by TB from those of non-TB origins.

CD4+ T cells from human neonates and infants are poised spontaneously to run a nonclassical IL-4 program

Senescence or biological aging impacts a vast variety of molecular and cellular processes. To date, it is unknown whether CD4(+) Th cells display an age-dependent bias for development into specific subpopulations. In this study, we show the appearance of a distinct CD4(+) T cell subset expressing IL-4 at an early stage of development in infant adenoids and cord blood that is lost during aging. We identified by flow cytometric, fluorescent microscopic, immunoblot, and mass spectrometric analysis a population of CD4(+) T cells that expressed an unglycosylated isoform of IL-4. This T cell subpopulation was found in neonatal but not in adult CD4(+) T cells. Furthermore, we show that the mRNA of the Th2 master transcription factor GATA3 is preferentially expressed in neonatal CD4(+) T cells. The Th2 phenotype of the IL-4(+)CD4(+) T cells could be reinforced in the presence of TGF-β. Although the IL-4(+)CD4(+) T cells most likely originate from CD31(+)CD4(+) T recent thymic emigrants, CD31 was downregulated prior to secretion of IL-4. Notably, the secretion of IL-4 requires a so far unidentified trigger in neonatal T cells. This emphasizes that cytokine expression and secretion are differentially regulated processes. Our data support the hypothesis of an endogenously poised cytokine profile in neonates and suggest a link between cytokine production and the developmental stage of an organism. The determination of the IL-4 isoform-expressing cells in humans might allow the identification of Th2 precursor cells, which could provide novel intervention strategies directed against Th2-driven immunopathologies such as allergies.

Incidence and risk factors for exacerbations of asthma during pregnancy

Background

Asthma is one of the most common chronic diseases among pregnant women. Acute exacerbations of asthma during pregnancy have an unfavorable impact on pregnancy outcome. This review provides an overview of current knowledge of incidence, mechanisms, and risk factors for acute exacerbations of asthma during pregnancy.

Methods

A narrative literature review was carried out using the PubMed database.

Results

During pregnancy, up to 6% of women with asthma are hospitalized for an acute exacerbation. The maternal immune system is characterized by a very high T-helper-2:T-helper-1 cytokine ratio during pregnancy and thereby provides an environment essential for fetal survival but one that may aggravate asthma. Cells of the innate immune system such as monocytes and neutrophils are also increased during pregnancy, and this too can exacerbate maternal asthma. Severe or difficult-to-control asthma appears to be the major risk factor for exacerbations during pregnancy, but studies also suggest that nonadherence with controller medication and viral infections are important triggers of exacerbations during pregnancy. So far, inconsistent findings have been reported regarding the effect of fetal sex on exacerbations during pregnancy. Other risk factors for exacerbation during pregnancy include obesity, ethnicity, and reflux, whereas atopy does not appear to be a risk factor.

Discussion

The incidence of asthma exacerbations during pregnancy is disturbingly high. Severe asthma – better described as difficult-to-control asthma – nonadherence with controller therapy, viral infections, obesity, and ethnicity are likely to be important risk factors for exacerbations of asthma during pregnancy, whereas inconsistent findings have been reported with regard to the importance of sex of the fetus.

Pretreatment levels of circulating Th1 and Th2 cytokines, and their ratios, are associated with ER-negative and triple negative breast cancers

Immune signatures in breast tumors differ by estrogen receptor (ER) status. The purpose of this study was to assess associations between ER phenotypes and circulating levels of cytokines that co-ordinate cell-mediated [T-helper type 1 (Th1)] and humoral [T-helper type 2 (Th2)] immunity. We conducted a case-case comparison of 523 women with newly diagnosed breast cancer to evaluate associations between 27 circulating cytokines, measured using Luminex XMap technology, and breast cancer phenotypes [ER(-) vs. ER(+); triple negative breast cancer (TNBC) vs. luminal A (LumA)]. Ratios of Th1 to Th2 cytokines were also evaluated. Levels of interleukin (IL)-5, a Th-2 cytokine, were higher in ER(-) than in ER(+) tumors. The highest tertile of IL-5 was more strongly associated with ER(-) (OR = 2.33, 95 % CI 1.40-3.90) and TNBCs (OR = 2.78, 95 % CI 1.53-5.06) compared to ER(+) and LumA cancers, respectively, particularly among premenopausal women (OR = 4.17, 95 % CI 1.86-9.34, ER(-) vs. ER(+); OR = 5.60, 95 % CI 2.09-15.01, TNBC vs. LumA). Elevated Th1 cytokines were also detected in women with ER(-) and TNBCs, with women in the highest tertile of interferon α2 (OR = 2.39, 95 % CI 1.31-4.35) or tumor necrosis factor-α (OR = 2.27, 95 % CI 1.21-4.26) being twice as likely to have TNBC versus LumA cancer. When cytokine ratios were examined, women with the highest ratios of Th1 cytokines to IL-5 levels were least likely to have ER(-) or TNBCs compared to ER(+) or LumA cancers, respectively. The strongest associations were in premenopausal women, who were up to 80 % less likely to have TNBC than LumA cancers (IL-12p40/IL-5, OR = 0.19, 95 % CI 0.07-0.56). These findings indicate that immune function is associated with ER(-) and TNBC and may be most relevant among younger women, who are likely to be diagnosed with these aggressive phenotypes.

Maternal immune status in pregnancy is related to offspring's immune responses and atopy risk

BACKGROUND

The influence of maternal immune responses in pregnancy on children's immune competence and the development of atopic diseases later in life are poorly understood. To determine potential maternal effects on the maturation of children's immune system and resulting disease risks, we analysed immune responses in mother-child pairs in a prospective birth cohort study.

METHODS

Within the Lifestyle and Environmental factors and their Influence on Newborns Allergy risk (LINA) study, concentrations of Th1/Th2/Th17 and inflammatory cytokines/chemokines as well as IgE were measured in phytohemagglutinin and lipopolysaccharide stimulated maternal blood in the 34th week of gestation and in corresponding children's blood at birth and 1 year after (n = 353 mother-child pairs). Information on atopic outcomes during the first year of life was obtained from questionnaires.

RESULTS

Concentrations of inflammatory markers, excepting TNF-α, were manifold higher in cord blood samples compared with maternal blood. Th1/Th2 cytokines were lower in children's blood with a Th2 bias at birth. Maternal inflammatory parameters (MCP-1, IL-10, TNF-α) in pregnancy showed an association with corresponding cytokines blood levels in children at the age of one. High maternal IgE concentrations in pregnancy were associated with increased children's IgE at birth and at the age of one, whereas children's atopic dermatitis (AD) was determined by maternal AD.

CONCLUSIONS

Maternal inflammatory cytokines during pregnancy correlate with children's corresponding cytokines at the age of one but are not related to IgE or AD. While maternal IgE predicts children's IgE, AD in children is only associated with maternal disease.

The hygiene hypothesis revisited: role of materno-fetal interactions

For 20 years, the hygiene hypothesis has dominated attempts to explain the increasing prevalence of allergic disease. A causal link between maternal innate immune response during pregnancy and disease protection in the offspring was recently demonstrated. Central to this was a systemically diffused signal that downregulated Toll-like receptor expression in placental tissues. Herein we develop the hypothesis that maternal systemic regulatory mechanisms operational during pregnancy could impact allergic disease risk of the offspring, depending on the type of inflammatory response from which they originate. Classic microbial-derived, mild, subacute inflammation provides a protective signal, whereas allergic inflammation provides a negative one. Mild, subacute inflammation of pregnant women leads to systemically diffused signals manifest in the gestation-associated tissues and by the fetus and newborn as a dampened inflammatory response. The converse is true if the mother has allergic inflammation during pregnancy. In both cases, these impact on development of the airways and of balanced immune function at birth and in early postnatal life. Thus, we seem to be at the dawn of a new incarnation of the hygiene hypothesis in which the pregnant woman's inflammatory response is crucial to determining the child's likelihood of developing allergic disease.

Asthma in pregnancy

Worldwide the prevalence of asthma among pregnant women is on the rise, and pregnancy leads to a worsening of asthma for many women. This article examines the changes in asthma that may occur during pregnancy, with particular reference to asthma exacerbations. Asthma affects not only the mother but the baby as well, with potential complications including low birth weight, preterm delivery, perinatal mortality, and preeclampsia. Barriers to effective asthma management and opportunities for optimized care and treatment are discussed, and a summary of the clinical guidelines for the management of asthma during pregnancy is presented.

Th1/Th2 patterns and balance in cytokine production in the parents and infants of a large birth cohort

Regulation of human immune cell cytokine production in vivo is not well understood due in part to limitations on imposing experimental conditions. We proposed that life-imposed conditions (pregnancy, birth, age, gender), combined with large sample size, repeat sampling, and family-based recruitment would serve to reveal peripheral blood cell-derived cytokine patterns reflective of in vivo regulation regarding Th1/Th2 balance and familial correlation. Mononuclear cells were obtained from 483 trios in the Tucson Infant Immune Study: from mothers pre- and postpartum, infants at birth and at 3 mo, and fathers. Con A/PMA-stimulated supernatants were assayed by ELISA for IFN-gamma, IL-4, IL-13, IL-5, and IL-10 and allergen-stimulated supernatants for IFN-gamma, IL-4, and IL-13. Mitogen-stimulated prepartum samples were not globally Th2 biased, differing from postpartum only by a modestly reduced IFN-gamma:IL-5 ratio. Prepartum samples actually produced less IL-10 and IL-13 although more IL-5 than paternal samples. Newborns were also not globally Th2 biased, with mitogen stimulation producing approximately 10-fold less IL-4, IL-5, and IFN-gamma than adults but only 2- to 3-fold less IL-13 and IL-10. Despite these group differences, all cytokines showed marked positive intraindividual correlations (all p < 0.001). Allergen stimulation gave results consistent with a lack of global Th2 bias. Mitogen stimulation revealed parent-child and parent-parent correlations. Thus, rather than a global Th2 bias, cytokine production in pregnant mothers and newborns appears regulated so as to maintain a relative balance among the cytokines, with the nature of the balance differing in mothers and infants and with production influenced by familial factors that include shared environment.

Gender difference, sex hormones, and immediate type hypersensitivity reactions

Gender differences in the development and prevalence of human diseases have long been recognized. Immense interest grows in the understanding of the role of sex hormones in the homeostasis of immunity. Asthma predominates in boys before puberty and this gender preference reverses after puberty and in adulthood, when adult women tend to have a more severe disease, often recalcitrant to treatment. Atopic eczema in preschool children shows insignificant gender difference or male preponderance in different studies, with more adult females suffering from atopic eczema. The limited data on the prevalence of immediate hypersensitivity to hymenoptera venom show controversial results. Discrepancy exists regarding the gender difference in food allergy, with females reporting significantly more allergic reactions in questionnaire studies. In general, adverse reactions to nonionic iodinated radiocontrast media are more commonly observed in females. The course of allergic diseases varies unpredictably during pregnancy, whereas hormone replacement therapy in postmenopausal women usually has a favorable influence on the course of asthma. Experiments in rodents confirm an effect of estrogens on mast cell activation and allergic sensitization, while progesterone is shown to suppress histamine release but potentiate IgE induction. Dehydroepiandrosterone may antagonize the production of Th2 cytokines but the effect of testosterone and the other androgens remains less defined. Actual data from human studies are lacking.

Maternal and cord plasma cytokine and chemokine profile in pregnancies complicated by asthma

The mechanisms contributing to worsening of asthma during pregnancy have not been well characterized. Both asthma and pregnancy are conditions associated with a skewing of the immune response from T helper (Th) 1 toward a Th2 response. We hypothesise that worsening of asthma during pregnancy may be due to an enhanced production of circulating proinflammatory cytokines and chemokines and this may be modified by the use of inhaled glucocorticoid treatment. Peripheral blood was collected from asthmatic (n=35) and control non-asthmatic patients (n=13) in the third trimester (30-37 weeks) of pregnancy. Fetal blood was collected from the umbilical vein of the placenta after delivery from normal (n=24) and pregnancies complicated by asthma (n=24). Plasma samples were assayed for IL-6, -8, eotaxin and RANTES using conventional ELISA. In addition, a range of Th1 and Th2 cytokines measured using Luminex system. There were no significant differences in the levels of maternal IL-6, IL-8, eotaxin and RANTES between asthmatics and nonasthmatics. The results of this study suggest that the presence of asthma does not result in an enhanced circulation of Th2 related cytokines and chemokines during the third trimester of pregnancy. Furthermore peripheral blood cytokine concentrations appear unaffected by inhaled glucocorticoid treatment. Cord plasma eotaxin concentrations were increased in pregnancies complicated by asthma, compared with control. This is the first study to show increased eotaxin production in the feto-placental unit of asthmatic pregnancies and may be one mechanism by which allergy susceptibility is increased in the offspring of asthmatic women.