Epigenetic regulation of T-helper cell differentiation, memory, and plasticity in allergic asthma

Human milk oligosaccharides in preventing food allergy: A review through gut microbiota and immune regulation

Food allergy (FA) has increasingly attracted global attention in past decades. However, the mechanism and effect of FA are complex and varied, rendering it hard to prevention and management. Most of the allergens identified so far are macromolecular proteins in food and may have potential cross-reactions. Human milk oligosaccharides (HMOs) have been regarded as an ideal nutrient component for infants, as they can enhance the immunomodulatory capacity to inhibit the progress of FA. HMOs may intervene in the development of allergies by modifying gut microbiota and increasing specific short-chain fatty acids levels. Additionally, HMOs could improve the intestinal permeability and directly or indirectly regulate the balance of T helper cells and regulatory T cells by enhancing the inflammatory signaling pathways to combat FA. This review will discuss the influence factors of FA, key species of gut microbiota involved in FA, types of FA, and profiles of HMOs and provide evidence for future research trends to advance HMOs as potential therapeutic aids in preventing the progress of FA.

DOT1L maintains NK cell phenotype and function for optimal tumor control

Histone methyltransferases (HMTs) are crucial in gene regulation and function, yet their role in natural killer (NK) cell biology within the tumor microenvironment (TME) remains largely unknown. We demonstrate that the HMT DOT1L limits NK cell conversion to CD49a+ CD49b+ intILC1, a subset that can be observed in the TME in response to stimulation with transforming growth factor (TGF)-β and is correlated with impaired tumor control. Deleting Dot1l in NKp46-expressing cells reveals its pivotal role in maintaining NK cell phenotype and function. Loss of DOT1L skews NK cells toward intILC1s even in the absence of TGF-β. Transcriptionally, DOT1L-null NK cells closely resemble intILC1s and ILC1s, correlating with altered NK cell responses and impaired solid tumor control. These findings deepen our understanding of NK cell biology and could inform approaches to prevent NK cell conversion to intILC1s in adoptive NK cell therapies for cancer.

Promyelocytic leukemia zinc finger controls type 2 immune responses in the lungs by regulating lineage commitment and the function of innate and adaptive immune cells

Type 2 immune responses are critical for host defense, mediate allergy and Th2-high asthma. The transcription factor, promyelocytic leukemia zinc finger (PLZF), has emerged as a significant regulator of type 2 inflammation in the lung; however, its exact mechanism remains unclear. In this review, we summarized recent findings regarding the ability of PLZF to control the development and function of innate lymphoid cells (ILCs), iNKT cells, memory T cells, basophils, and other immune cells that drive type 2 responses. We discussed the important role of PLZF in the pathogenesis of Th2-high asthma. Collectively, prior studies have revealed the critical role of PLZF in the regulation of innate and adaptive immune cells involved in type 2 inflammation in the lung. Therefore, targeting PLZF signaling represents a promising therapeutic approach to suppress Th2-high asthma.

Recent Developments in the Role of Histone Acetylation in Asthma

BACKGROUND

Epigenetic modifications are known to mediate both beneficial and unfavorable effects of environmental exposures on the development and clinical course of asthma. On the molecular level, epigenetic mechanisms participate in multiple aspects of the emerging and ongoing asthma pathology.

SUMMARY

Studies performed in the last several years expand our knowledge on the role of histone acetylation, a classical epigenetic mark, in the regulation of (patho)physiological processes of diverse cells playing a central role in asthma, including those belonging to the immune system (e.g., CD4+ T cells, macrophages) and lung structure (e.g., airway epithelial cells, pulmonary fibroblasts). Those studies demonstrate a number of specific histone acetylation-associated mechanisms and pathways underlying pathological processes characteristic for asthma, as well as report their modification modalities.

KEY MESSAGES

Dietary modulation of histone acetylation levels in the immune system might protect against the development of asthma and other allergies. Interfering with the enzymes controlling the histone acetylation status of structural lung and (local) immune cells might provide future therapeutic options for asthmatics. Despite some methodological obstacles, analysis of the histone acetylation levels might improve asthma diagnostics.

A review on ethnopharmacology, phytochemistry, pharmacology and potential uses of Portulaca oleracea L

ETHNOPHARMACOLOGICAL RELEVANCE

Portulaca oleracea L. (PO), popularly known as purslane, has been documented in ethnopharmacology in various countries and regions. Traditional application records indicated that PO might be used extensively to treat the common cold, dysentery, urinary tract infections, coughing, eye infections, skin problems, gynecological diseases, and pediatric illnesses.

AIM OF THE REVIEW

This paper includes a systematic review of the traditional usage, phytochemicals, pharmacological activity, and potential uses of PO to provide an overview of the research for further exploitation of PO resources.

MATERIALS AND METHODS

This article uses "Portulaca oleracea L." and "purslane" as the keywords and collects relevant information on PO from different databases, including PubMed, Web of Science, Springer, Science Direct, ACS, Wiley, CNKI, Baidu Scholar, Google Scholar, and ancient meteria medica.

RESULTS

PO is a member of the Portulacaceae family and is grown worldwide. Traditional Chinese medicine believes that purslane has the effect of improving eyesight, eliminating evil qi, quenching thirst, purgation, diuresis, hemostasis, regulating qi, promoting hair growth, detoxifying, and avoiding epidemic qi. Recent phytochemical investigations have shown that PO is a rich source of flavonoids, homoisoflavonoids, alkaloids, organic acids, esters, lignans, terpenoids, catecholamines, sterols, and cerebrosides. The purslane extracts or compounds have exhibited numerous biological activities such as anti-inflammatory, immunomodulatory, antimicrobial, antiviral, antioxidant, anticancer, renoprotective, hepatoprotective, gastroprotective, metabolic, muscle relaxant, anti-asthmatic and anti-osteoporosis properties. The significant omega-3 fatty acids, vital amino acids, minerals, and vitamins found in purslane also provide nutritional benefits. Purslane as a food/feed additive in the food industry and animal husbandry has caused concern. Its global wide distribution and tolerance to abiotic stress characteristics make it in the future sustainable development of agriculture a certain position.

CONCLUSIONS

Based on traditional usage, phytochemicals, and pharmacological activity, PO is a potential medicinal and edible plant with diverse pharmacological effects. Due to purslane's various advantages, it may have vast application potential in the food and pharmaceutical industries and animal husbandry.

H3K4 trimethylation regulates cancer immunity: a promising therapeutic target in combination with immunotherapy

With the advances in cancer immunity regulation and immunotherapy, the effects of histone modifications on establishing antitumor immunological ability are constantly being uncovered. Developing combination therapies involving epigenetic drugs (epi-drugs) and immune checkpoint blockades or chimeric antigen receptor-T cell therapies are promising to improve the benefits of immunotherapy. Histone H3 lysine 4 trimethylation (H3K4me3) is a pivotal epigenetic modification in cancer immunity regulation, deeply involved in modulating tumor immunogenicity, reshaping tumor immune microenvironment, and regulating immune cell functions. However, how to integrate these theoretical foundations to create novel H3K4 trimethylation-based therapeutic strategies and optimize available therapies remains uncertain. In this review, we delineate the mechanisms by which H3K4me3 and its modifiers regulate antitumor immunity, and explore the therapeutic potential of the H3K4me3-related agents combined with immunotherapies. Understanding the role of H3K4me3 in cancer immunity will be instrumental in developing novel epigenetic therapies and advancing immunotherapy-based combination regimens.

Schisandrin A ameliorates airway inflammation in model of asthma by attenuating Th2 response

Asthma is a persistent respiratory ailment that displays periodicity and is linked to the equilibrium of T cells. Several compounds obtained from Chinese herbal medicines display beneficial impacts on T cell regulation and the attenuation of inflammatory mediator synthesis. Schisandrin A, an active lignan derived from the Schisandra fruit, exhibits anti-inflammatory characteristics. In the present study, the network analysis conducted revealed that the nuclear factor-kappaB (NF-κB) signaling pathway is likely a prominent contributor to the anti-asthmatic effects of schisandrin A. In addition, it has been established that the inhibition of cyclooxygenase 2 (COX-2/PTGS2) is likely a significant factor in this process. The results of in vitro experiments have substantiated that schisandrin A can effectively lower the expression of COX-2 and inducible nitric oxide synthase (iNOS) in 16 HBE cells and RAW264.7 cells in a manner that is dependent on the dosage administered. It was able to effectively reduce the activation of the NF-κB signaling pathway while simultaneously improving the injury to the epithelial barrier function. Furthermore, an investigation utilizing immune infiltration as a metric revealed an inequity in Th1/Th2 cells and a surge in Th2 cytokines in asthma patients. In the OVA-induced asthma mice model, it was observed that schisandrin A treatment effectively suppressed inflammatory cell infiltration, reduced the Th2 cell ratio, inhibited mucus secretion, and prevented airway remodeling. To summarize, the administration of schisandrin A has been found to effectively alleviate the symptoms of asthma by impeding the production of inflammation, which includes reducing the Th2 cell ratio and improving the integrity of the epithelial barrier function. These findings offer valuable insights into the potential therapeutic applications of schisandrin A for the treatment of asthma.

Climate change and public health: The effects of global warming on the risk of allergies and autoimmune diseases: The effects of global warming on the risk of allergies and autoimmune diseases

Global climate change and extreme weather events are associated with epigenetic modifications in immune cells, leading to the possible increased risk and prevalence of allergies and autoimmune diseases.

Studies on the role of non-coding RNAs in controlling the activity of T cells in asthma

Bronchial asthma, commonly known as asthma, is a chronic inflammatory disease characterized by airway inflammation, increased responsiveness and changes in airway structure. T cells, particularly T helper cells, play a crucial role in the disease. Non-coding RNAs, which are RNAs that do not code for proteins, mainly include microRNAs, long non-coding RNAs, and circular RNAs, play a role in regulating various biological processes. Studies have shown that non-coding RNAs have an important role in the activation and transformation of T cells and other biological processes in asthma. The specific mechanisms and clinical applications are worth further examination. This article reviews the recent research on the role of microRNAs, long non-coding RNAs and circular RNAs in T cells in asthma.

PLZF promotes the development of asthma tolerance via affecting memory phenotypes of immune cells

Clarifying the pathogenesis of asthma and/or identifying the specific pathway underlying oral asthma tolerance (OT) would be of great significance. In our previous study, promyelocytic leukemia zinc finger (PLZF), which reportedly regulates memory phenotypes, was found to promote ovalbumin (OVA)-induced OT. Therefore, this study aimed to explore the regulatory effects of PLZF on memory phenotypes in asthma and OT mouse models. We found that Zbtb16 (encoding PLZF) and PLZF⁺ cells were highly increased in OT lungs compared with asthmatic lungs. PLZF was co-expressed with GATA3, and IL-4⁺PLZF⁺ cells were significantly lower in OT lungs than in asthmatic lungs. Notably, memory cells were decreased in OT mice, and these mice had PLZF⁺ cells that expressed lower levels of CD44 than those of asthmatic mice. When Zbtb16 was overexpressed in splenic lymphocytes, the number of CD44⁺ cells decreased. There were increased memory cells in splenic lymphocytes after treatment with the supernatant of OVA-treated airway epithelial cells; however, this was reversed by Zbtb16 overexpression. Early respiratory syncytial virus infection increased memory cells and reduced PLZF⁺ cells in the OT mice. Collectively, these results indicate that PLZF may reduce the proportion of memory cells, thereby, promoting the establishment of OT.

The functions of polycomb group proteins in T cells

T cells are involved in many aspects of adaptive immunity, including autoimmunity, anti-tumor activity, and responses to allergenic substances and pathogens. T cells undergo comprehensive epigenome remodeling in response to signals. Polycomb group (PcG) proteins are a well-studied complex of chromatin regulators, conserved in animals, and function in various biological processes. PcG proteins are divided into two distinct complexes: PRC1 (Polycomb repressive complex 1) and PRC2. PcG is correlated with the regulation of T cell development, phenotypic transformation, and function. In contrast, PcG dysregulation is correlated with pathogenesis of immune-mediated diseases and compromised anti-tumor responses. This review discusses recent findings on the involvement of PcG proteins in T cell maturation, differentiation, and activation. In addition, we explore implications in the development of the immune system diseases and cancer immunity, which offers promising targets for various treatment protocols.

Pyroptosis and respiratory diseases: A review of current knowledge

Pyroptosis is a relatively newly discovered programmed cell death accompanied by an inflammatory response. In the classical view, pyroptosis is mediated by caspases-1,-4,-5,-11 and executed by GSDMD, however, recently it was demonstrated that caspase-3 and-8 also participate in the process of pyroptosis, by cleaving GSDMD/E and GSDMD respectively. Different from autophagy and apoptosis, many pores are formed on the cell membrane during pyroptosis, which makes the cell membrane lose its integrity, eventually leading to the release of cytokines interleukin(IL)-1β and IL-18. When the body is infected with pathogens or exposed to some stimulations, pyroptosis could play an immune defense role. It is found that pyroptosis exists widely in infectious and inflammatory respiratory diseases such as acute lung injury, bronchial dysplasia, chronic obstructive pulmonary disease, and asthma. Excessive pyroptosis may accompany airway inflammation, tissue injury, and airway damage, and induce an inflammatory reaction, leading to more serious damage and poor prognosis of respiratory diseases. This review summarizes the relationship between pyroptosis and related respiratory diseases.

Sanzi Yangqin Decoction Alleviates Allergic Asthma by Modulating Th1/Th2 Balance: Coupling Network Pharmacology with Biochemical Pharmacology

This study aimed to verify that Sanzi Yangqin Decoction (SYD) can relieve asthma in mice and explore the effect on TH1/Th2 balance. The targets of SYD and asthma were explored from the public database using various methods. The potential targets and signaling pathways were identified by KEGG enrichment analysis from DAVID database. Mice asthma models were established using OVA and aluminum hydroxide. Lung tissues of mice were stained with HE and Masson. The contents of IFN-γ, IL-4, and TNF-α in BALF and IgE in mouse serum were detected using ELISA. In addition, the changes in Th1 and Th2 cells of the spleen were detected by flow cytometry. Fourteen core targets including IL4, IFNG, and MMP9 were identified for the treatment of asthma by SYD. The content of IL-4 in the lung tissue and BALF was gradually decreased with the increase in SYD concentration, while the IFN-γ was gradually increased. The drug significantly reduced IgE levels in serum and TNF-α in BALF. The number of Th1 cells in the spleen increased, while Th2 cells decreased in a concentration-dependent manner. SYD can alleviate pulmonary inflammation, restore Th1/Th2 balance, and relieve asthma.

HPLC-DAD analysis of Quercus leucotrichophora extract and appraisal of its antiasthmatic potential via modulation of aquaporins, inflammatory, and oxidative stress biomarkers in Albino mice

Herbal drugs offer an alternative approach for the treatment of diseases like asthma due to low cost and comparatively less adverse effects in contrast to synthetic drugs. Leaves of Quercus leucotrichophora are traditionally used for the treatment of asthma. The study was aimed to assess the anti-asthmatic activity of Quercus leucotrichophora (QL) methanolic (QLME) and aqueous extracts (QLAE) in ovalbumin-(OVA) induced asthma and chemical characterization of QL extract by High Performance Liquid Chromatography-Diode array detector (HPLC-DAD). Animals were inoculated with OVA (i.p) on day 1 and 14 followed by intranasal challenge on 27th and 29th day. Both extracts of QL at 600, 300 and 150 mg/kg and dexamethasone (2 mg/kg) l were administered consecutively from days 15-26 via oral gavage. The QL extracts notably reduced (p < 0.0001-p < 0.05) total and differential leukocyte counts in blood and BALF and serum IgE levels in contrast to disease control. Both extracts and Dex substantially improved activities of superoxide dismutase, catalase, and GSH, while reduced malondialdehyde level in treated mice. Treatment with extracts and Dex caused significant (p < 0.0001-p < 0.05) downregulation of tumor necrosis factor-α, interleukin-4, - 5, - 13, - 6, - 1β, and NF-κB whereas, increased expression of Aquaporin (AQP) 1 and AQP5 in contrast to disease control. It was inferenced from findings that both extract of QL exhibited notable antiasthmatic potential might be due to presence of Daidzein-glucuronic acid, 3-Hydroxyphloretin 6'-hexoside, Catechin, Quercetin, and Kaemferol.

Anti-inflammatory activities of Qingfei oral liquid and its influence on respiratory microbiota in mice with ovalbumin-induced asthma

Dysbiosis of respiratory microbiota is closely related to the pathophysiological processes of asthma, including airway inflammation. Previous studies have shown that Qingfei oral liquid (QF) can alleviate airway inflammation and airway hyper-responsiveness in respiratory syncytial virus-infected asthmatic mice, but its effect on the respiratory microbiota is unknown. We therefore aimed to observe the effects of QF on airway inflammation and respiratory microbiota in ovalbumin (OVA)-induced asthmatic mice. We also explored the potential mechanism of QF in reducing airway inflammation by regulating respiratory microbiota. Hematoxylin and eosin as well as periodic acid-Schiff staining were performed to observe the effects of QF on lung pathology in asthmatic mice. Cytokine levels in bronchoalveolar lavage fluid (BALF) specimens were also measured. Changes in respiratory microbiota were analyzed using 16S rRNA gene sequencing, followed by taxonomical analysis. In order to verify the metagenomic function prediction results, the expression of key proteins related to the MAPK and NOD-like receptor signaling pathways in the lung tissues were detected by immunohistochemistry. The current study found that QF had a significant anti-inflammatory effect in the airways of asthmatic mice. This is mainly attributed to a reduction in lung pathology changes and regulating cytokine levels in BALF. Analysis of the respiratory microbiota in asthmatic mice showed that the abundance of Proteobacteria at the phylum level and Pseudomonas at the genus level increased significantly and QF could significantly regulate the dysbiosis of respiratory microbiota in asthmatic mice. Metagenomic functional prediction showed that QF can downregulate the MAPK and Nod-like receptor signaling pathways. Immunohistochemical results showed that QF could downregulate the expression of p-JNK, p-P38, NLRP3, Caspase-1, and IL-1β, which are all key proteins in the signaling pathway of lung tissue. Our study therefore concluded that QF may reduce airway inflammation in asthmatic mice by regulating respiratory microbiota, and to the possibly downregulate MAPK and Nod-like receptor signaling pathways as its underlying mechanism.

IL-36 Cytokines: Their Roles in Asthma and Potential as a Therapeutic

Interleukin (IL)-36 cytokines are members of the IL-1 superfamily, which consists of three agonists (IL-36α, IL-36β and IL-36γ) and an IL-36 receptor antagonist (IL-36Ra). IL-36 cytokines are crucial for immune and inflammatory responses. Abnormal levels of IL-36 cytokine expression are involved in the pathogenesis of inflammation, autoimmunity, allergy and cancer. The present study provides a summary of recent reports on IL-36 cytokines that participate in the pathogenesis of inflammatory diseases, and the potential mechanisms underlying their roles in asthma. Abnormal levels of IL-36 cytokines are associated with the pathogenesis of different types of asthma through the regulation of the functions of different types of cells. Considering the important role of IL-36 cytokines in asthma, these may become a potential therapeutic target for asthma treatment. However, existing evidence is insufficient to fully elucidate the specific mechanism underlying the action of IL-36 cytokines during the pathological process of asthma. The possible mechanisms and functions of IL-36 cytokines in different types of asthma require further studies.

Alternatively activated macrophages promote airway inflammation through JAK3-STAT5-Fra2 in asthma

BACKGROUND

Fos-related antigen-2 (Fra-2) is a transcription factor belonging to the activator protein 1 (AP-1) family, which is associated with many chronic airway diseases such as asthma. Alternatively activated (M2) macrophages are associated with Fra2 in airway diseases such as pulmonary fibrosis. However, there is no specific study that explores the relationship between M2 macrophages and Fra2 in asthma.

OBJECTIVE

We hypothesized that a potential mechanism of allergic asthma could be that Fra2 is highly expressed in M2 macrophages through JAK3-STAT5 and facilitates the production of downstream T-helper 2 (Th2) cytokines, thus promoting the pathogenesis of asthma.

METHODS

Peripheral venous blood and airway tissue samples of patients with asthma and controls were obtained. Moreover, a C57BL/6 mouse model of asthma was established. Fra2 expression was detected using immunohistochemistry and immunofluorescence. Macrophages were obtained by flow sorting, and expression of the JAK3-STAT5-Fra2 signaling pathway was determined using PCR and western blotting. Enzyme-linked immunosorbent assay was used to determine M2 macrophage-associated Th2-type cytokine levels.

RESULTS

Fra2 was highly expressed in patients with asthma and asthmatic mice. The JAK3-STAT5 was a signal pathway related to the high expression of Fra2 in M2 macrophages. Moreover, we found that Fra2 could affect the production of Th2 cytokines downstream of M2 macrophages, including interleukin 4 (IL-4) and IL-13.

CONCLUSION

M2 macrophages could promote airway inflammation through JAK3-STAT5-Fra2 to induce allergic asthma. Our study offers a new insight to further understand the pathogenesis of asthma and also provides a new direction for targeted treatment.

Polystichum braunii ameliorates airway inflammation by attenuation of inflammatory and oxidative stress biomarkers, and pulmonary edema by elevation of aquaporins in ovalbumin-induced allergic asthmatic mice

Asthma is a chronic inflammation of pulmonary airways associated with bronchial hyper-responsiveness. The study was aimed to validate the folkloric use of Polystichum braunii (PB) against ovalbumin (OVA)-induced asthmatic and chemical characterization OF both extracts. Allergic asthma was developed by intraperitoneal sensitization with an OVA on days 1 and 14 followed by intranasal challenge. Mice were treated with PB methanolic (PBME) and aqueous extract (PBAE) orally at 600, 300, and 150 mg/kg and using dexamethasone (2 mg/kg) as standard from day 15 to 26. High performance liquid chromatography-diode array detector analysis revealed the presence of various bioactive compounds such as catechin, vanillic acid, and quercetin. The PBME and PBAE profoundly (p < 0.0001-0.05) declined immunoglobulin E level, lungs wet/dry weight ratio, and total and differential leukocyte count in blood and bronchial alveolar lavage fluid of treated mice in contrast to disease control. Histopathological examination showed profoundly decreased inflammatory cell infiltration and goblet cell hyperplasia in treated groups. Both extracts caused significant (p < 0.0001-0.05) diminution of IL-4, IL-5, IL-13, IL-6, IL-1β, TNF-α, and NF-κB and upregulation of aquaporins (1 and 5), which have led to the amelioration of pulmonary inflammation and attenuation of lung edema in treated mice. Both extracts profoundly (p < 0.0001-0.05) restored the activities of SOD, CAT, GSH and reduced the level of MDA dose dependently. Both extracts possessed significant anti-asthmatic action mainly PBME 600 mg/kg might be due to phenols and flavonoids and could be used as a potential therapeutic option in the management of allergic asthma.

TET2 Regulates 5-Hydroxymethylcytosine Signature and CD4+ T-Cell Balance in Allergic Rhinitis

Purpose

Previous studies have shown the role of ten-eleven translocation 2 (TET2) in CD4⁺ T cells. However, its function in CD4⁺ T cells under allergic inflammation is unclear. We aimed to investigate the epigenomic distribution of DNA 5-hydroxymethylcytosine (5hmC) and the role of TET2 in CD4⁺ T cells of allergic rhinitis (AR).

Methods

The hMeDIP-seq was performed to identify sequences with 5hmC deposition in CD4⁺ T cells of AR patients. Tet2-deficient or wild type mice were stimulated with ovalbumin (OVA) to develop an AR mouse model. The histopathology in nasal mucosae, Th1/Th2/Treg/Th17 cell percentage, concentrations of Th-related cytokines, expression of Tet and differential hydroxymethylated genes (DhMG), and the global deposition of 5hmC in sorted CD4⁺ T cells were detected.

Results

Epigenome-wide 5hmC landscape and DhMG in the CD4⁺ T cells of AR patients were identified. Tet2 depletion did not led to spontaneous inflammation. However, under the stimulation of allergen, OVA, loss of Tet2 resulted in the exacerbation of allergic inflammation, which was characterized by severer allergic symptoms, more inflammatory cells infiltrating the nasal lamina propria, sharper imbalances between Th1/Th2 and Treg/Th17 cells, and excessive secretion of OVA-specific IgE and Th2-related cytokines. Moreover, altered mRNA production of several DhMG and sharp decrease in 5hmC deposition were also observed in Tet2-deficient OVA-exposed mice.

Conclusions

TET2 may regulate DNA 5hmC, DhMG expressions, and CD4⁺ T cell balance in AR.

Toward a Framework for Assessing Privacy Risks in Multi-Omic Research and Databases

While the accumulation and increased circulation of genomic data have captured much attention over the past decade, privacy risks raised by the diversification and integration of omics have been largely overlooked. In this paper, we propose the outline of a framework for assessing privacy risks in multi-omic research and databases. Following a comparison of privacy risks associated with genomic and epigenomic data, we dissect ten privacy risk-impacting omic data properties that affect either the risk of re-identification of research participants, or the sensitivity of the information potentially conveyed by biological data. We then propose a three-step approach for the assessment of privacy risks in the multi-omic era. Thus, we lay grounds for a data property-based, 'pan-omic' approach that moves away from genetic exceptionalism. We conclude by inviting our peers to refine these theoretical foundations, put them to the test in their respective fields, and translate our approach into practical guidance.

A cellular census of human peripheral immune cells identifies novel cell states in lung diseases

Increasing evidence supports a central role of the immune system in lung diseases. Understanding how immunological alterations between lung diseases provide opportunities for immunotherapy. Exhausted T cells play a key role of immune suppression in lung cancer and chronic obstructive pulmonary disease was proved in our previous study. The present study aims to furthermore define molecular landscapes and heterogeneity of systemic immune cell target proteomic and transcriptomic profiles and interactions between circulating immune cells and lung residential cells in various lung diseases. We firstly measured target proteomic profiles of circulating immune cells from healthy volunteers and patients with stable pneumonia, stable asthma, acute asthma, acute exacerbation of chronic obstructive pulmonary disease, chronic obstructive pulmonary disease and lung cancer, using single-cell analysis by cytometry by time-of-flight with 42 antibodies. The nine immune cells landscape was mapped among those respiratory system diseases, including CD4+ T cells, CD8+ T cells, dendritic cells, B cells, eosinophil, γδT cells, monocytes, neutrophil and natural killer cells. The double-negative T cells and exhausted CD4+ central memory T cells subset were identified in patients with acute pneumonia. This T subset expressed higher levels of T-cell immunoglobulin and mucin domain-containing protein 3 (Tim3) and T-cell immunoreceptor with Ig and ITIM domains (TIGIT) in patients with acute pneumonia and stable pneumonia. Biological processes and pathways of immune cells including immune response activation, regulation of cell cycle and pathways in cancer in peripheral blood immune cells were defined by bulk RNA sequencing (RNA-seq). The heterogeneity among immune cells including CD4+ , CD8+ T cells and NK T cells by single immune cell RNA-seq with significant difference was found by single-cell sequencing. The effect of interstitial telocytes on the immune cell types and immune function was finally studied and the expressions of CD8a and chemokine C-C motif receptor 7 (CCR7) were increased significantly in co-cultured groups. Our data indicate that proteomic and transcriptomic profiles and heterogeneity of circulating immune cells provides new insights for understanding new molecular mechanisms of immune cell function, interaction and modulation as a source to identify and develop biomarkers and targets for lung diseases.

Inflammation in Asthma Pathogenesis: Role of T cells, Macrophages, Epithelial Cells and Type 2 Inflammation

Asthma is a chronic disease with abnormal inflammatory and immunological responses. The disease initiated by antigens in subjects with genetic susceptibility. However, environmental factors play a role in the initiation and exacerbation of asthma attack. Asthma is T helper 2 (Th2)-cell-mediated disease. Recent studies indicated that asthma is not a single disease entity, but it is with multiple phenotypes and endotypes. The pathophysiological changes in asthma included a series of subsequent continuous vicious circle of cellular activation contributed to induction of chemokines and cytokines that potentiate inflammation. The heterogeneity of asthma influenced the treatment response. The asthma pathogenesis driven by varied set of cells such as eosinophils, basophils, neutrophils, mast cells, macrophages, epithelial cells and T cells. In this review the role of T cells, macrophage, and epithelial cells are discussed.

Respiratory Microbiota Profiles Associated With the Progression From Airway Inflammation to Remodeling in Mice With OVA-Induced Asthma

Background

The dysbiosis of respiratory microbiota plays an important role in asthma development. However, there is limited information on the changes in the respiratory microbiota and how these affect the host during the progression from acute allergic inflammation to airway remodeling in asthma.

Objective

An ovalbumin (OVA)-induced mouse model of chronic asthma was established to explore the dynamic changes in the respiratory microbiota in the different stages of asthma and their association with chronic asthma progression.

Methods

Hematoxylin and eosin (H&E), periodic acid-schiff (PAS), and Masson staining were performed to observe the pathological changes in the lung tissues of asthmatic mice. The respiratory microbiota was analyzed using 16S rRNA gene sequencing followed by taxonomical analysis. The cytokine levels in bronchoalveolar lavage fluid (BALF) specimens were measured. The matrix metallopeptidase 9 (MMP-9) and vascular endothelial growth factor (VEGF-A) expression levels in lung tissues were measured to detect airway remodeling in OVA-challenged mice.

Results

Acute allergic inflammation was the major manifestation at weeks 1 and 2 after OVA atomization stimulation, whereas at week 6 after the stimulation, airway remodeling was the most prominent observation. In the acute inflammatory stage, Pseudomonas was more abundant, whereas Staphylococcus and Cupriavidus were more abundant at the airway remodeling stage. The microbial compositions of the upper and lower respiratory tracts were similar. However, the dominant respiratory microbiota in the acute inflammatory and airway remodeling phases were different. Metagenomic functional prediction showed that the pathways significantly upregulated in the acute inflammatory phase and airway remodeling phase were different. The cytokine levels in BALF and the expression patterns of proteins associated with airway remodeling in the lung tissue were consistent with the metagenomic function results.

Conclusion

The dynamic changes in respiratory microbiota are closely associated with the progression of chronic asthma. Metagenomic functional prediction indicated the changes associated with acute allergic inflammation and airway remodeling.

Association of the Risk of Childhood Asthma at Age 6 With Maternal Allergic or Immune-Mediated Inflammatory Diseases: A Nationwide Population-Based Study

Objective: This study aimed to assess the associations of the risk of asthma diagnosed in children aged 6 years or younger and having maternal immune-mediated inflammatory diseases (IMIDs), including systemic lupus erythematosus (SLE), systemic sclerosis (SSc), inflammatory myositis, rheumatoid arthritis (RA), Sjögren's syndrome (SS), ankylosing spondylitis (AS), and autoimmune thyroiditis. Methods: A total of 628,878 singleton newborns documented in 2006-2009 and followed up for at least 6 years were identified. Overall, 153,085 (24.3%) children developed asthma at the age of ≤ 6 years. Two groups of maternal ages, i.e., <35 and ≥35 years, were evaluated. The associations of the risk of asthma occurring in children who were 6 years old or younger and had maternal IMIDs were examined. Results: The risk of asthma increased in children whose mothers had SLE [odds ratio (OR), 1.13; 95% confidence intervals (CI), 1.00-1.27; p = 0.04), RA (OR, 1.21; 95% CI, 1.07-1.38; p = 0.003), inflammatory myositis (OR, 1.41; 95% CI, 1.12-1.74; p = 0.003), asthma (OR, 1.58; 95% CI, 1.52-1.63), allergic rhinitis (OR, 1.30; 95% CI, 1.28-1.32), or atopic dermatitis (OR, 1.07; 95% CI, 1.02-1.12). Conversely, this increased risk was not observed in children whose mothers had AS (OR, 1.02; 95% CI, 0.87-1.20), SS (OR, 0.96; 95% CI, 0.86-1.07), SSc (OR, 1.28; 95% CI, 0.77-2.14), or autoimmune thyroiditis (OR, 1.01; 95% CI, 0.95-1.07). Other risk factors of childhood asthma included high urbanization level, preterm birth, and low birth weight. Conclusion: The risk of childhood asthma at 6 years of age increased in children whose mothers suffered from SLE, RA, inflammatory myositis, asthma, allergic rhinitis, and atopic dermatitis.

Potential role for EZH2 in promotion of asthma through suppression of miR-34b transcription by inhibition of FOXO3

Highly expressed enhancer of zeste homolog 2 (EZH2) has been associated with many kinds of cancers and other diseases, while its functional role in asthma is largely unknown. In our study, we investigated the molecular mechanism of EZH2 in the development of asthma. An ovalbumin-induced mouse asthma model was established, followed by injection of short hairpin RNA (sh)-EZH2, overexpression-B-cell translocation gene 2 (oe-BTG2), microRNA (miR)-34b agomir as well as their corresponding controls. Next, primary bronchial epithelial cells were isolated and cultured, followed by treatment of oe-FOXO3, miR-34b inhibitor, sh-EZH2, oe-BTG2, and corresponding controls. The effects of EZH2 on inflammation were evaluated by determining levels of inflammatory factors interleukin (IL)-4, IL-5, IL-13, IL-17, and protein levels of transforming growth factor β, matrix metalloproteinase-9, and tissue inhibitor of metalloproteinases-1. The interactions between EZH2 and forkhead box O3 (FOXO3), between FOXO3 and miR-34b promoter, and between miR-34b and BTG2 were analyzed by conducting dual-luciferase reporter and chromatin immunoprecipitation assays. Notably, EZH2 and BTG2 were significantly overexpressed, while FOXO3 and miR-34b were obviously underexpressed in asthma. EZH2 silencing led to inhibited inflammation though upregulation of FOXO3, which could bind to the miR-34b promoter and facilitate its expression. In turn, miR-34b reduced BTG2 expression by targeting its 3'untranslated region. Our study provides evidence that EZH2 promotes asthma progression by regulating the FOXO3-miR-34b-BTG2 axis.

Novel therapeutic approaches for cutaneous T cell lymphomas

Introduction: Cutaneous T-cell lymphoma (CTCL) is a rare non-Hodgkin's lymphoma, characterized by malignant T cells infiltrating the skin. CTCL exhibits vast heterogeneity which complicates diagnosis and therapeutic strategies. Current CTCL treatment includes skin-directed therapies (such as topical corticosteroid, topical mechlorethamine, topical bexarotene, ultraviolet phototherapy and localized radiotherapy), total skin electron beam therapy and systemic therapies. Elucidation of molecular and signaling pathways underlying CTCL pathogenesis leads to identification of innovative and personalized treatment schemes.Areas covered: The authors reviewed the molecular and immunological aspects of CTCL with special focus on Mycosis Fungoides (MF), Sézary Syndrome (SS) and associated systemic treatment. A literature search was conducted in PubMed and Web of Science for peer-reviewed articles published until November 2020. Novel treatment approaches including retinoids, targeted therapies, immune checkpoint and JAK/STAT inhibitors, histones deacetylase (HDAC) and mTOR inhibitors as well as proteasome inhibitors, are discussed as potential therapeutic tools for the treatment of CTCL.Expert opinion: Novel therapeutic agents exhibit potential beneficial effects in CTCL patients of high need for therapy such as refractory early stage cutaneous and advanced stage disease. Therapeutic schemes employing a combination of novel agents with current treatment options may prove valuable for the future management of CTCL patients.

The Concept of Pathogenic TH2 Cells: Collegium Internationale Allergologicum Update 2021

T helper (TH) cells have evolved into distinct subsets that mediate specific immune responses to protect the host against a myriad of infectious and noninfectious challenges. However, if dysregulated, TH-cell subsets can cause inflammatory disease. Emerging evidence now suggests that human allergic disease is caused by a distinct subpopulation of pathogenic TH2 cells. Pathogenic TH2 cells from different type-2-driven diseases share a core phenotype and show overlapping functional attributes. The unique differentiation requirements, activating signals, and metabolic characteristics of pathogenic TH2 cells are just being discovered. A better knowledge of this particular TH2 cell population will enable the specific targeting of disease-driving pathways in allergy. In this review, we introduce a rational for classifying TH cells into distinct subsets, discuss the current knowledge on pathogenic TH2 cells, and summarize their involvement in allergic diseases.

Interferon characterization associates with asthma and is a potential biomarker of predictive diagnosis

Interferon (IFN) plays a role in immune and inflammation responses. However, the effect of IFN in asthma is still not fully clear. The present study was conducted to better understand the role of IFN signatures in asthma. Blood samples from case–control studies (study 1: 348 asthmas and 39 normal controls and validation study 2: 411 asthmas and 87 normal controls) were enrolled. The single-sample gene set enrichment analysis (ssGSEA) method was used to quantify the levels of 74 IFN signatures. Gene Ontology analysis and pathway function analysis were performed for functional analysis and a protein–protein interaction (PPI) network was constructed. The area under the curve (AUC) value was used to evaluate the diagnostic ability. In our work, IFN-γ response-DN, negative regulation of IFN-γ secretion, IFNG pathway, negative regulation of response to IFN-γ, and type 1 IFN biosynthetic process showed higher levels in asthma. Functional analysis demonstrated that pathway and biological process involved in IFN signaling pathway, regulation of type 1 IFN production and response to IFN-γ. Hub IFN-related genes were identified, and their combination as biomarker exhibited a good diagnostic capacity for asthma (AUC = 0.832). These findings offered more insight into the underlying mechanism of how IFN signatures affected asthma. The use of the easy-to-apply IFN-related genes might serve as a promising blood-based biomarker for early diagnosis of asthma.

Epimedin C modulates the balance between Th9 cells and Treg cells through negative regulation of noncanonical NF-κB pathway and MAPKs activation to inhibit airway inflammation in the ovalbumin-induced murine asthma model

Allergic asthma is a common airway inflammatory disease and mainly caused by abnormal immune responses to allergens and viruses. The precise mechanisms of airway inflammation and airway hyper-responsiveness (AHR) are still not completely understood. CD4⁺ helper T cells (Th cells) serve as critical regulators of allergic immunity. The imbalance between T helper 9 (Th9) cells and forkhead box protein 3 (Foxp3)⁺ regulatory T (Treg) cells may contribute to airway inflammation in asthma. Epimedin C, a dominant compound isolated from Herba Epimedii, has shown anti-inflammatory effects and the immunoregulatory activity, such as increase of lymphocyte proliferation. However, the protective role of epimedin C in an experimental model of ovalbumin (OVA)-induced allergic airway inflammation and the underlying mechanism remain unknown. Female BALB/c mice were sensitized by intraperitoneal injection (i.p.) of OVA plus aluminum hydroxide (Alum) and subsequently challenged with an aerosol of 3% OVA in saline. Mice were treated with different concentrations of epimedin C (20 mg/kg/d, 40 mg/kg/d, 80 mg/kg/d) for 4 weeks. Experimental endpoints were evaluated via the analysis of AHR to acetyl-β-methacholine (Mch), differential inflammatory cell counts, concentrations of cytokines interleukin-9 (IL-9), IL-4 and IL-10 in bronchoalveolar lavage fluid (BALF), serum OVA-specific IgE level, as well as airway inflammation, mucus secretion and collagen deposition in mice. Mechanistically, we investigated the percentages of Th9 cells and Treg cells, as well as mRNA levels of IL-9 and transcription factor Foxp3 in lungs. Furthermore, the proteins expression of nuclear factor-κB (NF-κB) family members p105/p50, RelA, p100/p52 and RelB, as well as mitogen-activated protein kinase (MAPK) family members extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 MAPK was detected. Epimedin C dose-dependently attenuated AHR, airway inflammation, mucus hypersecretion and collagen deposition in OVA-induced murine asthma model. The expression levels of IL-9, IL-4 and OVA-specific IgE were significantly decreased while IL-10 was increased by epimedin C. We further confirmed that epimedin C decreased the percentage of lung Th9 cells with lower mRNA expression of IL-9 and increased the percentage of lung Treg cells with higher mRNA expression of Foxp3. In addition, epimedin C dose-dependently decreased the protein levels of p52, RelB, phosphorylation of ERK1/2 and p38 MAPK which are pivotal to the development of Th9 cells and Treg cells. Collectively, epimedin C could inhibit pathophysiological features of asthma by reconstruction of the balance between Th9 cells and Treg cells through regulation of the noncanonical NF-κB p52/RelB pathway and MAPKs activation. These findings suggest epimedin C as a potential remedy for inflammatory airway diseases.

GITRL on dendritic cells aggravates house dust mite-induced airway inflammation and airway hyperresponsiveness by modulating CD4+ T cell differentiation

Background

Glucocorticoid-induced tumor necrosis factor receptor family-related protein ligand (GITRL) plays an important role in tumors, autoimmunity and inflammation. However, GITRL is not known to modulate the pathogenesis of allergic asthma. In this study, we investigated whether regulating GITRL expressed on dendritic cells (DCs) can prevent asthma and to elucidate its mechanism of action.

Methods

In vivo, the role of GITRL in modulating house dust mite (HDM)-induced asthma was assessed in adeno-associated virus (AAV)-shGITRL mice. In vitro, the role of GITRL expression by DCs was evaluated in LV-shGITRL bone marrow dendritic cells (BMDCs) under HDM stimulation. And the direct effect of GITRL was observed by stimulating splenocytes with GITRL protein. The effect of regulating GITRL on CD4⁺ T cell differentiation was detected. Further, GITRL mRNA in the peripheral blood of asthmatic children was tested.

Results

GITRL was significantly increased in HDM-challenged mice. In GITRL knockdown mice, allergen-induced airway inflammation, serum total IgE levels and airway hyperresponsiveness (AHR) were reduced. In vitro, GITRL expression on BMDCs was increased after HDM stimulation. Further, knocking down GITRL on DCs partially restored the balance of Th1/Th2 and Th17/Treg cells. Moreover, GITRL stimulation in vitro inhibited Treg cell differentiation and promoted Th2 and Th17 cell differentiation. Similarly, GITRL mRNA expression was increased in the peripheral blood from asthmatic children.

Conclusions

This study identified a novel role for GITRL expressed by DCs as a positive regulator of CD4⁺ T cells responses in asthma, which implicates that GITRL inhibitors may be a potential immunotherapy for asthma.

Altered Immune Regulation of Dendritic Cells and Enhanced Cytokine Production of T Cells in the Pathogenesis of Eosinophilic Chronic Rhinosinusitis

INTRODUCTION

Eosinophilic chronic rhinosinusitis (ECRS) is a refractory chronic disease defined by recurrent nasal polyps with severe eosinophilic infiltration. This is mainly due to enhanced type 2-dominant immune responses, but the underlying mechanism is still not fully understood.

OBJECTIVE AND METHODS

In the present study, we aimed to determine the characteristics of dendritic cells (DCs) and cytokine profiles of T cells in the peripheral blood of individuals with ECRS and age- and sex-matched healthy controls (HC).

RESULTS AND CONCLUSION

The ratios of myeloid (m)DC1s to DCs and PD-L1+ mDC1s to mDC1s were higher in ECRS patients than in HC. The proportions of plasmacytoid (p)DCs in DCs, and human leukocyte antigen-DR+ pDCs and ILT3+ pDCs in pDCs were lower in ECRS patients than in HC. In a characterization of T cells, IL-4+CD4+, IFN-γ+CD4+, IL-4+IFN-γ+CD4+, IL-4+Foxp3+CD4+, IFN-γ+Foxp3+CD4+, IFN-γ+IL-4-Foxp3-CD4+, IL-4+CD8+, IL-4+IFN-γ+CD8+, and IL-4+Foxp3+CD8+ T-cell populations were significantly higher in ECRS patients than in HC. These results suggest that the enhanced immune regulation of mDC1, diminished capacity of pDCs, and increased proportion of the T-cell phenotypes in peripheral blood might be factors in ECRS pathogenesis.

The Cxxc1 subunit of the Trithorax complex directs epigenetic licensing of CD4+ T cell differentiation

Different dynamics of gene expression are observed during cell differentiation. In T cells, genes that are turned on early or turned off and stay off have been thoroughly studied. However, genes that are initially turned off but then turned on again after stimulation has ceased have not been defined; they are obviously important, especially in the context of acute versus chronic inflammation. Using the Th1/Th2 differentiation paradigm, we found that the Cxxc1 subunit of the Trithorax complex directs transcription of genes initially down-regulated by TCR stimulation but up-regulated again in a later phase. The late up-regulation of these genes was impaired either by prolonged TCR stimulation or Cxxc1 deficiency, which led to decreased expression of Trib3 and Klf2 in Th1 and Th2 cells, respectively. Loss of Cxxc1 resulted in enhanced pathogenicity in allergic airway inflammation in vivo. Thus, Cxxc1 plays essential roles in the establishment of a proper CD4⁺ T cell immune system via epigenetic control of a specific set of genes.

Diagnostic and Therapeutic Value of Hsa_circ_0002594 for T Helper 2-Mediated Allergic Asthma

INTRODUCTION

Circular RNAs (circRNAs) are an endogenous mircoRNA sponge that could act as potential biomarkers for the diagnosis and treatment of diseases. However, the role of circRNAs in asthma is far from clear.

OBJECTIVE

The aim of this study is to assess the diagnostic and therapeutic value of hsa_circ_0002594 for T helper (Th) 2-mediated allergic asthma.

METHODS

The expression profiles of hsa_circ_0002594 in CD4+ T cells were revealed by circRNA microarray. Hsa_circ_0002594 expression was confirmed via quantitative real-time PCR (qRT-PCR) in asthmatic patients and healthy subjects. Hsa_circ_0002594 levels were compared between subgroups. The clinical diagnostic abilities and therapeutic response of hsa_circ_0002594 were evaluated. The analyses utilized included a student's t test, nonparametric tests, Spearman's rank-order correlation, Fisher's exact test, and the generation of receiver operating characteristic (ROC) curves.

RESULTS

Hsa_circ_0002594 was upregulated and positively correlated with fraction of exhaled nitric oxide while negatively correlated with methacholine dose producing a decrease of 20% from baseline in forced expiratory volume in the first second (PD20) in CD4+ T cells of asthma. Furthermore, hsa_circ_0002594 expression was higher in subgroups with a family history, skin pricking test (SPT)-positive, or Th2-high. The hsa_circ_0002594-high subgroup was more frequently associated with Th2-high biomarker profiles and positive SPT. Hsa_circ_0002594 was decreased after inhaled corticosteroids (ICS) treatment. ROC curve analyses of hsa_circ_0002594 showed high area under the curve values in the presence of ICS or not.

CONCLUSIONS

Our data suggested that hsa_circ_0002594 was upregulated in CD4+ T cells and might have potential value in the diagnosis and treatment of Th2-mediated allergic asthma.

Maternal vitamin D deficiency impairs Treg and Breg responses in offspring mice and deteriorates allergic airway inflammation

Background

Vitamin D (VitD) can regulate immune responses and maternal VitD-deficiency can affect immune responses in the offspring. This study aimed at investigating the effects of maternal VitD-deficiency during pregnancy on Treg and Breg responses in offspring mice with house dust mite (HDM)-induced allergic airway inflammation.

Methods

Female BALB/c mice were randomized and fed with normal chow or VitD-deficient diet until their offspring weaned. The offspring mice were fed with normal chow and injected with vehicle or HDM to induce allergic airway inflammation. The levels of serum 25(OH)D, cytokines and infiltrate numbers as well as percentages of Tregs and Bregs in the bronchoalveolar lavage fluid (BALF) were analyzed. The relative levels of VitD receptor (VDR), VitD-binding protein (VDBP), Cytochromes P450 (CYP) 27b1, and CYP24A1 mRNA transcripts in the lungs of different groups of mice were measured.

Results

Maternal VitD-deficiency significantly reduced serum 25(OH)D levels in offspring mice. VitD-deficiency significantly increased the relative levels of VDR, VDBP and CYP27B1 mRNA transcripts, but decreased CYP24A1 expression in the lungs of mice. In comparison with the control mice, significantly elevated levels of pro-inflammatory cytokines, increased numbers of lymphocytes and eosinophils, but decreased levels of anti-inflammatory cytokines were detected in the BALF of VitD-deficient mice. VitD-deficiency significantly increased the frequency of Th1, Th2, Th9, Th17 cells, but decreased regulatory T (Tregs) and B cells (Bregs) in the BALF of mice with allergic airway inflammation.

Conclusion

Maternal VitD-deficiency lowed serum 25(OH)D levels and enhanced HDM-induced allergic airway inflammation in the offspring by impairing Breg and Treg responses.

Long Noncoding RNAs in the Regulation of Asthma: Current Research and Clinical Implications

Asthma is a chronic airway inflammatory disorder related to variable expiratory airflow limitation, leading to wheeze, shortness of breath, chest tightness, and cough. Its characteristic features include airway inflammation, airway remodeling and airway hyperresponsiveness. The pathogenesis of asthma remains extremely complicated and the detailed mechanisms are not clarified. Long noncoding RNAs (lncRNAs) have been reported to play a prominent role in asthma and function as modulators of various aspects in pathological progress of asthma. Here, we summarize recent advances of lncRNAs in asthma pathogenesis to guide future researches, clinical treatment and drug development, including their regulatory functions in the T helper (Th) 1/Th2 imbalance, Th17/T regulatory (Treg) imbalance, eosinophils dysfunction, macrophage polarization, airway smooth muscle cells proliferation, and glucocorticoid insensitivity.

B cells polarize pathogenic inflammatory T helper subsets through ICOSL-dependent glycolysis

B cells constitute abundant cellular components in inflamed human tissues, but their role in pathogenesis of inflammatory T helper (TH) subsets is still unclear. Here, we demonstrate that B cells, particularly resting naïve B cells, have a previously unrecognized helper function that is involved in shaping the metabolic process and subsequent inflammatory differentiation of T-cell receptor-primed TH cells. ICOS/ICOSL axis-mediated glucose incorporation and utilization were crucial for inflammatory TH subset induction by B cells, and activation of mTOR was critical for T cell glycolysis in this process. Consistently, upon encountering ICOSL+ B cells, activated effector memory TH cells from patients with rheumatoid arthritis or systemic lupus erythematosus spontaneously differentiated into inflammatory TH subsets. Immunotherapy using rituximab that specifically depleted B cells in patients with rheumatoid arthritis efficiently abrogated the capabilities of memory TH cells to incorporate and use glucose, thereby impairing the pathogenic differentiation of inflammatory TH subsets.

New variants in NLRP3 inflammasome genes increase risk for asthma and Blomia tropicalis-induced allergy in a Brazilian population

Atopic asthma is a chronic lung disease of lower airways caused mainly due to action of T-helper (Th) 2 type cytokines, eosinophilic inflammation, mucus hypersecretion and airway remodelling. Interleukin (IL)-33 increases type 2 immunity polarization in airway playing critical role in eosinophilic asthma. On the other hand, NLRP3 inflammasome activation results in the release of caspase-1 (Casp-1) which, in its turn, promotes IL-33 inactivation. Recent studies have shown associations between NLRP3 variants and inflammatory diseases. However, no study with genes in NLRP3 inflammassome route has been conducted so far with asthma and atopy in any population to date. Blood samples were collected from 1246 asthmatic and non-asthmatic children. Associations were tested for single nucleotide polymorphism (SNP)s in NLRP3 and CASP1 with asthma and markers of atopy and in cultures stimulated with Blomia tropicalis (Bt) mite crude extract. The T allele of rs4925648 (NLRP3) was associated with increased asthma risk (OR 1.50, P = 0.005). In addition, the T allele of rs12130711 polymorphism, whithin the same gene, acted as a protector factor for asthma (OR 0.78, P = 0.038). On the other hand, the C allele of rs4378247 NLRP3 variant was associated with lower levels of IL-13 production when peripheral blood cells were stimulated with Bt (OR 0.39, P = 4E-04). In addition, the greater the number of risk alleles in IL33/NLRP3/CASP1 route the greater was the risk for asthma. The T allele of rs7925706 CASP1 variant was also associated with increased risk for asthma (OR 1.47, P = 0.008). In addition, this same allele increased the eosinophil counts in blood (mm3) in asthmatic individuals compared with non-asthmatic (P = 0.0004). These results suggest that NLRP3 and CASP1 polymorphisms may be associated with susceptibility for asthma and markers of atopy in our population.

The Role of T Cells and Macrophages in Asthma Pathogenesis: A New Perspective on Mutual Crosstalk

Asthma is associated with innate and adaptive immunity mediated by immune cells. T cell or macrophage dysfunction plays a particularly significant role in asthma pathogenesis. Furthermore, crosstalk between them continuously transmits proinflammatory or anti-inflammatory signals, causing the immune cell activation or repression in the immune response. Consequently, the imbalanced immune microenvironment is the major cause of the exacerbation of asthma. Here, we discuss the role of T cells, macrophages, and their interactions in asthma pathogenesis.

Multiple developmental pathways lead to the generation of CD4 T-cell memory

Long-term immunological memory mediated by CD4 T cells provides a rapid protection against previously encountered pathogens or antigens. However, it is still controversial how memory CD4 T cells are generated and maintained. Unclear definitions of T-cell memory may be partially responsible for this controversy. It is becoming clear that diverse pathways are responsible for the differentiation and long-term persistence of memory T cells. We herein discuss the diversity of memory cell generation, describing a novel population of resting memory CD4 T cells and their precursors.

IL‑27 suppresses airway inflammation, hyperresponsiveness and remodeling via the STAT1 and STAT3 pathways in mice with allergic asthma

Type 2 cytokine-associated immunity may be involved in the pathogenesis of allergic asthma. Although interleukin 27 (IL-27) has been reported as an initiator and suppressor of T-helper 1 (Th1) and T-helper 2 (Th2) responses, respectively, its effects on the development of asthma remain unclear. In the present study, mice were induced and challenged with ovalbumin and received subsequent intranasal administration of IL-27. Total and differential cell counts were determined from Wright-Giemsa-stained cytospins, whereas the cytokine levels were detected using ELISA. In addition, the expression levels of signal transducer and activator of transcription (STAT) 1, STAT3, GATA-binding protein-3 (GATA3) and T-bet (T-box transcription factor) were analyzed in T cells by western blot analysis. Their corresponding mRNA expression levels were determined by quantitative PCR. Airway remodeling was assessed by conventional pathological techniques. The results indicated that intranasal administration of IL-27 ameliorated airway inflammation and hyperresponsiveness in an acute model of asthma. Furthermore, IL-27 prevented airway remodeling in a chronic model of asthma. Following administration of IL-27, the mRNA expression levels of STAT1 and T-bet were upregulated, while those of GATA3 were downregulated. Moreover, the phosphorylation levels of STAT1 and STAT3 were increased. Taken together, these findings demonstrated that intranasal administration of IL-27 ameliorated Th2-related allergic lung inflammation and remodeling in mouse models of asthma by repairing both the STAT1 and STAT3 pathways.

Bifidobacterium infantis Relieves Allergic Asthma in Mice by Regulating Th1/Th2

Background

Bifidobacteria are among the probiotics used in treating intestinal diseases and are rarely used for allergic asthma treatment. The present study investigated the mechanism of B. infantis in treating allergic asthma in mice.

Material/Methods

A total of 40 male Balb/c mice were randomized into control, ovalbumin (OVA), montelukast (Mon), and B. infantis (B10) groups, and allergic asthma was induced in the OVA, Mon, and B10 groups. Airway reactivity was measured on day 29 by methacholine at various doses. The numbers of total cells and inflammatory cells in bronchoalveolar lavage fluid (BALF) were counted by blood cell counter and Diff-Quik staining. Hematoxylin-eosin (HE) staining was performed to observe inflammatory cell infiltration in lung tissues. Total IgE and OVA-specific IgE in serum were measured by ELISA. Mucin 5AC expression was detected by Western blot to evaluate airway obstruction. The levels of Th1 (IFN-γ, IL-2) and Th2 (IL-4, IL-5, IL-13) cytokines in BALF and tissues were detected by ELISA and qRT-PCR, respectively.

Results

The mice in the OVA group had airway hyperreactivity, while the symptoms in the B10 group and Mon group were effectively relieved. B10 reduced the number of inflammatory cells in BALF as well as inflammatory cell infiltration in tissues. Moreover, the levels of total serum IgE, OVA-specific IgE, and Mucin 5AC were increased in the OVA group, but were reduced in the Mon group and B10 group. B. infantis increased the levels of Th1 cytokines and decreased those of Th2 cytokines.

Conclusions

B. infantis can reduce the infiltration of inflammatory cells induced by OVA-specific antibodies in mice. B. infantis has therapeutic effects on allergic asthma by promoting Th1 and inhibiting Th2 immune responses.

Pathogenic mechanisms and the potential of drug therapies for aortic aneurysm

Aortic aneurysm is a permanent focal dilation of the aorta. It is usually an asymptomatic disease but can lead to sudden death due to aortic rupture. Aortic aneurysm-related mortalities are estimated at ∼200,000 deaths per year worldwide. Because no pharmacological treatment has been found to be effective so far, surgical repair remains the only treatment for aortic aneurysm. Aortic aneurysm results from changes in the aortic wall structure due to loss of smooth muscle cells and degradation of the extracellular matrix and can form in different regions of the aorta. Research over the past decade has identified novel contributors to aneurysm formation and progression. The present review provides an overview of cellular and noncellular factors as well as enzymes that process extracellular matrix and regulate cellular functions (e.g., matrix metalloproteinases, granzymes, and cathepsins) in the context of aneurysm pathogenesis. An update of clinical trials focusing on therapeutic strategies to slow abdominal aortic aneurysm growth and efforts underway to develop effective pharmacological treatments is also provided.

Sirtuin 1 regulates mitochondrial function and immune homeostasis in respiratory syncytial virus infected dendritic cells

Respiratory syncytial virus (RSV) is the major cause of lower respiratory tract infection in children worldwide. Sirtuin 1 (SIRT1), a NAD+ dependent deacetylase, has been associated with induction of autophagy, reprogramming cellular metabolism, and regulating immune mediators. In this study, we investigated the role of SIRT1 in bone marrow dendritic cell (BMDC) function during RSV infection. SIRT1 deficient (SIRT1 -/-) BMDC showed a defect in mitochondrial membrane potential (Δ⍦m) that worsens during RSV infection. This defect in Δ⍦m caused the generation of elevated levels of reactive oxygen species (ROS). Furthermore, the oxygen consumption rate (OCR) was reduced as assessed in Seahorse assays, coupled with lower levels of ATP in SIRT1-/- DC. These altered responses corresponded to altered innate cytokine responses in the SIRT1-/- DC in response to RSV infection. Reverse Phase Protein Array (RPPA) functional proteomics analyses of SIRT1-/- and WT BMDC during RSV infection identified a range of differentially regulated proteins involved in pathways that play a critical role in mitochondrial metabolism, autophagy, oxidative and ER stress, and DNA damage. We identified an essential enzyme, acetyl CoA carboxylase (ACC1), which plays a central role in fatty acid synthesis and had significantly increased expression in SIRT1-/- DC. Blockade of ACC1 resulted in metabolic reprogramming of BMDC that ameliorated mitochondrial dysfunction and reduced pathologic innate immune cytokines in DC. The altered DC responses attenuated Th2 and Th17 immunity allowing the appropriate generation of anti-viral Th1 responses both in vitro and in vivo during RSV infection thus reducing the enhanced pathogenic responses. Together, these studies identify pathways critical for appropriate DC function and innate immunity that depend on SIRT1-mediated regulation of metabolic processes.

Eighty-eight variants highlight the role of T cell regulation and airway remodeling in asthma pathogenesis

Asthma is one of the most common chronic diseases affecting both children and adults. We report a genome-wide association meta-analysis of 69,189 cases and 702,199 controls from Iceland and UK biobank. We find 88 asthma risk variants at 56 loci, 19 previously unreported, and evaluate their effect on other asthma and allergic phenotypes. Of special interest are two low frequency variants associated with protection against asthma; a missense variant in TNFRSF8 and 3‘ UTR variant in TGFBR1. Functional studies show that the TNFRSF8 variant reduces TNFRSF8 expression both on cell surface and in soluble form, acting as loss of function. eQTL analysis suggests that the TGFBR1 variant acts through gain of function and together with an intronic variant in a downstream gene, SMAD3, points to defective TGFβR1 signaling as one of the biological perturbations increasing asthma risk. Our results increase the number of asthma variants and implicate genes with known role in T cell regulation, inflammation and airway remodeling in asthma pathogenesis.

Asthma is a common allergic airway disease with significant inter-individual heterogeneity. Here, Olafsdottir et al. report a genome-wide meta-analysis of two large population-based cohorts to identify sequence variants that associate with asthma risk and perform follow-up functional analyses on a protective loss-of-function variant in TNFRSF8.

The role of epigenetics in the development of childhood asthma

Introduction: The development of childhood asthma is caused by a combination of genetic factors and environmental exposures. Epigenetics describes mechanisms of (heritable) regulation of gene expression that occur without changes in DNA sequence. Epigenetics is strongly related to aging, is cell-type specific, and includes DNA methylation, noncoding RNAs, and histone modifications.Areas covered: This review summarizes recent epigenetic studies of childhood asthma in humans, which mostly involve studies of DNA methylation published in the recent five years. Environmental exposures, in particular cigarette smoking, have significant impact on epigenetic changes, but few of these epigenetic signals are also associated with asthma. Several asthma-associated genetic variants relate to DNA methylation. Epigenetic signals can be better understood by studying their correlation with gene expression, which revealed higher presence and activation of blood eosinophils in asthma. Strong associations of nasal methylation signatures and atopic asthma were identified, which were replicable across different populations.Expert commentary: Epigenetic markers have been strongly associated with asthma, and might serve as biomarker of asthma. The causal and longitudinal relationships between epigenetics and disease, and between environmental exposures and epigenetic changes need to be further investigated. Efforts should be made to understand cell-type-specific epigenetic mechanisms in asthma.