Aspergillus fumigatus extract modulates human eosinophils via NOD2 and oxidative stress.

BACKGROUND: Aspergillus fumigatus is a pathogenic fungus known to be associated with severe asthma and allergic bronchopulmonary mycosis. However, the precise mechanisms underlying airway inflammation remain unclear. In this study, we investigated the direct modulation of human eosinophils by A. fumigatus and identified the specific mechanism of airway inflammation. METHODS: Eosinophils isolated from healthy subjects were stimulated with extracts of A. fumigatus. Multi-omics analysis, comprising transcriptomic and proteomic analyses, was performed. The expression of specific factors was evaluated using quantitative real-time polymerase chain reaction and flow cytometry. Mechanistic analyses were performed using NOD2 inhibitor and N-acetyl-l-cysteine (NAC). RESULTS: The A. fumigatus extract changed the expression of adhesion molecules (CD62L and CD11b) and CD69 on the surface of eosinophils, without affecting their viability, via nucleotide-binding oligomerization domain-containing protein 2 (NOD2) but not protease activity. Investigation using kinase inhibitors showed that A. fumigatus extract-induced modulation was partly mediated via p38 mitogen-activated protein kinases. Multi-omics analysis revealed that A. fumigatus-induced gene and protein expression profiles were characterized by the upregulation of oxidative stress-related molecules, including heat shock proteins (HSP90AA1, HSP90AB1, SRXN1, and HMOX1). NOD2 inhibitor and NAC differentially inhibited A. fumigatus-induced inflammatory changes. Additional multi-omics analysis identified that NOD2 signaling induced gene signatures different from those of interleukin (IL)-5 and elicited synergistic change with IL-5. CONCLUSIONS: A. fumigatus modulates human eosinophils via NOD2 and oxidative stress-mediated signaling. NOD2 signaling potentiated IL-5-induced activation, suggesting its pathogenic role in type 2 inflammation. NOD2 inhibitors and antioxidants can have therapeutic potential against A. fumigatus-related allergic disorders.

Multiomics analysis identified IL-4-induced IL1RL1high eosinophils characterized by prominent cysteinyl leukotriene metabolism.

BACKGROUND: Clinical studies have demonstrated that IL-4, a type 2 cytokine, plays an important role in the pathogenesis of chronic rhinosinusitis and eosinophilic asthma. However, the direct effect of IL-4 on eosinophils remains unclear. OBJECTIVE: We aimed to elucidate the inflammatory effects of IL-4 on the functions of human eosinophils. METHODS: A multiomics analysis comprising transcriptomics, proteomics, lipidomics, quantitative RT-PCR, and flow cytometry was performed by using blood eosinophils from healthy subjects stimulated with IL-4, IL-5, or a combination thereof. RESULTS: Transcriptomic and proteomic analyses revealed that both IL-4 and IL-5 upregulate the expression of γ-gultamyl transferase 5, a fatty acid-metabolizing enzyme that converts leukotriene C4 into leukotriene D4. In addition, IL-4 specifically upregulates the expression of IL-1 receptor-like 1 (IL1RL1), a receptor for IL-33 and transglutaminase-2. Additional transcriptomic analysis of cells stimulated with IL-13 revealed altered gene expression profiles, characterized by the upregulation of γ-gultamyl transferase 5, transglutaminase-2, and IL1RL1. The IL-13-induced changes were not totally different from the IL-4-induced changes. Lipidomic analysis revealed that IL-5 and IL-4 additively increased the extracellular release of leukotriene D4. In vitro experiments revealed that STAT6 and IL-4 receptor-α control the expression of these molecules in the presence of IL-4 and IL-13. Analysis of eosinophils derived from patients with allergic disorders indicated the involvement of IL-4 and IL-13 at the inflamed sites. CONCLUSIONS: IL-4 induces the proallergic phenotype of IL1RL1high eosinophils, with prominent cysteinyl leukotriene metabolism via STAT6. These cellular changes represent potential therapeutic targets for chronic rhinosinusitis and eosinophilic asthma.

DOCK2 is involved in the host genetics and biology of severe COVID-19.

Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge1-5. Here we conducted a genome-wide association study (GWAS) involving 2,393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3,289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target.

The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force.

Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection.

A 70-Year-Old Woman With Long-Term Nonresolving Pneumonia.

CASE PRESENTATION: A 70-year-old woman who had received a diagnosis of pneumonia in the right lower lobe was treated with antibiotics at a general practitioner's clinic 9 months earlier. Her pneumonia had improved, but the cough and lung infiltrates persisted for > 6 months, so the patient was referred to our hospital. She had undergone surgery for breast cancer 30 years earlier but had no other medical history. She was not taking any medications and had no history of smoking, including passive smoking.

Lysophosphatidylcholine Acyltransferase 1 Deficiency Promotes Pulmonary Emphysema via Apoptosis of Alveolar Epithelial Cells.

Chronic obstructive pulmonary disease (COPD) is primarily caused by inhalation of cigarette smoke and is the third leading cause of death worldwide. Pulmonary surfactant, a complex of phospholipids and proteins, plays an essential role in respiration by reducing the surface tension in the alveoli. Lysophosphatidylcholine acyltransferase 1 (LPCAT1) is an enzyme that catalyzes the biosynthesis of surfactant lipids and is expressed in type 2 alveolar epithelial cells. Its dysfunction is suggested to be involved in various lung diseases; however, the relationship between LPCAT1 and COPD remains unclear. To investigate the role of LPCAT1 in the pathology of COPD, we analyzed an elastase-induced emphysema model using Lpcat1 knockout (KO) mice. In Lpcat1 KO mice, elastase-induced emphysema was significantly exacerbated with increased apoptotic cells, which was not ameliorated by supplementation with dipalmitoylphosphatidylcholine, which is a major component of the surfactant synthesized by LPCAT1. We subsequently evaluated the effects of cigarette smoking on primary human type 2 alveolar epithelial cells (hAEC2s) and found that cigarette smoke extract (CSE) downregulated the expression of Lpcat1. Furthermore, RNA sequencing analysis revealed that the apoptosis pathway was significantly enriched in CSE-treated primary hAEC2s. Finally, we downregulated the expression of Lpcat1 using small interfering RNA, which resulted in enhanced CSE-induced apoptosis in A549 cells. Taken together, cigarette smoke-induced downregulation of LPCAT1 can promote the exacerbation of pulmonary emphysema by increasing the susceptibility of alveolar epithelial cells to apoptosis, thereby suggesting that Lpcat1 is a novel therapeutic target for irreversible emphysema.

TLR7 Agonist Suppresses Group 2 Innate Lymphoid Cell-mediated Inflammation via IL-27-Producing Interstitial Macrophages.

Group 2 innate lymphoid cells (ILC2s) play an important role in the pathophysiology of asthma via the robust production of type 2 cytokines. Recent studies have demonstrated that TLR7 (Toll-like receptor 7) signaling skews toward a type 1 inflammatory response in asthma, which may lead to the development of novel treatment strategies. However, the effect of TLR7 signaling on ILC2-dependent nonallergic eosinophilic inflammation remains unclear. In this study, we investigated the effects of R848, a TLR7 agonist, in a mouse model of IL-33-induced eosinophilic airway inflammation. Intranasal administration of R848 decreased infiltration of airway eosinophils and ILC2s, mucus production in epithelial cells, and type 2 cytokine production. Flow cytometric analysis identified an increased number of interstitial macrophages (IMs) expressing a high level of TLR7 in the lung upon IL-33 stimulation. IL-33-induced IMs also expressed high levels of alternatively activated (M2)-type genes and chemokines (CCL17 and CCL24). However, R848 stimulation modified these gene expressions and elicited the production of IL-27. Coculture experiments revealed that IL-33-induced IMs directly suppressed ILC2 activation in response to R848. In addition, the inhibitory effects of R848 on ILC2-induced type 2 inflammation were defective in WSX-1-deficient mice lacking the IL-27 receptor. Taken together, these findings indicate that R848 stimulates IL-33-induced IMs to suppress ILC2-mediated type 2 airway inflammation via IL-27. These findings highlight the therapeutic potential of TLR7 agonists and/or IL-27 cascades in nonallergic asthma.

COVID-19 shares clinical features with anti-melanoma differentiation-associated protein 5 positive dermatomyositis and adult Still's disease.

OBJECTIVES: To investigate the similarities and differences between Coronavirus disease 2019 (COVID-19) and autoimmune and autoinflammatory rheumatic diseases characterised by hyperferritinaemia, such as antimelanoma differentiation-associated protein 5 (MDA5) autoantibody-positive dermatomyositis and adult Still's disease. METHODS: We reviewed consecutive, newly diagnosed, untreated patients with COVID-19, anti-MDA5 dermatomyositis, or adult Still's disease. We compared their clinical, laboratory, and radiological characteristics, including the prevalence of macrophage activation syndrome and lung involvement in each disease. RESULTS: The numbers of patients with COVID-19, anti-MDA5 dermatomyositis, and adult-onset Still's disease with hyperferritinaemia (serum ferritin ≥500ng/dL) who were included for main analysis were 22, 14, and 59, respectively. COVID-19 and adult Still's disease both featured hyperinflammatory status, such as high fever and elevated serum C-reactive protein, whereas COVID-19 and anti-MDA5 dermatomyositis both presented with severe interstitial lung disease and hypoxaemia. While two-thirds of the patients in each group met the criteria for macrophage-activated syndrome that is used in systemic juvenile idiopathic arthritis, the HScore, an indicator of haemophagocytic lymphohistiocytosis, was low in anti-MDA5 dermatomyositis and COVID-19 even in severe or critical cases. The findings of chest computed tomography were similar between COVID-19 and anti-MDA5 dermatomyositis. CONCLUSIONS: COVID-19 shared clinical features with rheumatic diseases characterised by hyperferritinaemia, including anti-MDA5 dermatomyositis and adult Still's disease. These findings should be investigated further in order to shed light on the pathogenesis of not only COVID-19 but also the aforementioned rheumatic diseases.

Innate lymphoid cells support regulatory T cells in the intestine through interleukin-2.

Interleukin (IL)-2 is a pleiotropic cytokine that is necessary to prevent chronic inflammation in the gastrointestinal tract1-4. The protective effects of IL-2 involve the generation, maintenance and function of regulatory T (Treg) cells4-8, and the use of low doses of IL-2 has emerged as a potential therapeutic strategy for patients with inflammatory bowel disease9. However, the cellular and molecular pathways that control the production of IL-2 in the context of intestinal health are undefined. Here we show, in a mouse model, that IL-2 is acutely required to maintain Treg cells and immunological homeostasis throughout the gastrointestinal tract. Notably, lineage-specific deletion of IL-2 in T cells did not reduce Treg cells in the small intestine. Unbiased analyses revealed that, in the small intestine, group-3 innate lymphoid cells (ILC3s) are the dominant cellular source of IL-2, which is induced selectively by IL-1ß. Macrophages in the small intestine produce IL-1ß, and activation of this pathway involves MYD88- and NOD2-dependent sensing of the microbiota. Our loss-of-function studies show that ILC3-derived IL-2 is essential for maintaining Treg cells, immunological homeostasis and oral tolerance to dietary antigens in the small intestine. Furthermore, production of IL-2 by ILC3s was significantly reduced in the small intestine of patients with Crohn's disease, and this correlated with lower frequencies of Treg cells. Our results reveal a previously unappreciated pathway in which a microbiota- and IL-1ß-dependent axis promotes the production of IL-2 by ILC3s to orchestrate immune regulation in the intestine.

The group 2 innate lymphoid cell (ILC2) regulatory network and its underlying mechanisms.

Group 2 innate lymphoid cells (ILC2s) play critical roles in the induction of type 2 inflammation, response to parasite infection, metabolic homeostasis, and tissue repair. These multifunctional roles of ILC2s are tightly controlled by complex regulatory systems in the local microenvironment, the disruption of which may cause various health problems. This review summarizes up-to-date knowledge regarding positive and negative regulators for ILC2s based on their function and signaling pathways, including activating cytokines (IL-33, IL-25; MAPK, NF-κB pathways), co-stimulatory cytokines (IL-2, IL-7, IL-9, TSLP; STAT5, IL-4; STAT6, TNF superfamily; MAPK, NF-κB pathways), suppressive cytokines (type1 IFNs, IFN-γ, IL-27; STAT1, IL-10, TGF-ß), transdifferentiation cytokines (IL-12; STAT4, IL-1ß, IL-18), lipid mediators (LTC4, LTD4, LTE4, PGD2; Ca2+ -NFAT pathways, PGE2, PGI2; AC/cAMP/PKA pathways, LXA4, LTB4), neuropeptides (NMU; Ca2+ -NFAT, MAPK pathways, VIP, CGRP, catecholamine, acetylcholine), sex hormones (androgen, estrogen), nutrients (butyrate; HDAC inhibitors, vitamins), and cell-to-cell interactions (ICOSL-ICOS; STAT5, B7-H6-NKp30, E-cadherin-KLRG1). This comprehensive review affords a better understanding of the regulatory network system for ILC2s, providing impetus to develop new treatment strategies for ILC2-related health problems.

A keratan sulfate disaccharide prevents inflammation and the progression of emphysema in murine models.

Emphysema is a typical component of chronic obstructive pulmonary disease (COPD), a progressive and inflammatory airway disease. However, no effective treatment currently exists. Here, we show that keratan sulfate (KS), one of the major glycosaminoglycans produced in the small airway, decreased in lungs of cigarette smoke-exposed mice. To confirm the protective effect of KS in the small airway, a disaccharide repeating unit of KS designated L4 ([SO3--6]Galß1-4[SO3--6]GlcNAc) was administered to two murine models: elastase-induced-emphysema and LPS-induced exacerbation of a cigarette smoke-induced emphysema. Histological and microcomputed tomography analyses revealed that, in the mouse elastase-induced emphysema model, administration of L4 attenuated alveolar destruction. Treatment with L4 significantly reduced neutrophil influx, as well as the levels of inflammatory cytokines, tissue-degrading enzymes (matrix metalloproteinases), and myeloperoxidase in bronchoalveolar lavage fluid, suggesting that L4 suppressed inflammation in the lung. L4 consistently blocked the chemotactic migration of neutrophils in vitro. Moreover, in the case of the exacerbation model, L4 inhibited inflammatory cell accumulation to the same extent as that of dexamethasone. Taken together, L4 represents one of the potential glycan-based drugs for the treatment of COPD through its inhibitory action against inflammation.

Phenotype of asthma related with high serum periostin levels.

BACKGROUND: Asthma is a heterogeneous disease composed of various phenotypes. Periostin, a molecule inducible with interleukin (IL)-4 or IL-13 in bronchial epithelial cells, is a biomarker of "TH2-high" asthma. The objective of this study is to examine whether the serum periostin concentrations are correlated with the severity, specific phenotype(s), or comorbidity of asthma. METHODS: Serum concentrations of periostin were measured in 190 Japanese asthmatic patients and 11 healthy controls. The protocol was registered under UMIN 000002980 in the clinical trial registry. RESULTS: The serum concentrations of periostin were significantly higher (P = 0.014) in asthmatics [70.0 (54.0-93.5) ng/ml] than in healthy subjects [57.0 (39.0-63.0) ng/ml], though we found no correlation between serum periostin concentrations and treatment steps required to control asthma. To characterize "high-periostin" phenotype(s), the patients with asthma were divided among tertiles based on the serum concentrations of periostin. The high-periostin group was older at onset of asthma (P = 0.04), had a higher prevalence of aspirin intolerance (P = 0.04) or concomitant nasal disorders (P = 0.03-0.001), higher peripheral eosinophil counts (P < 0.001), and lower pulmonary function (P = 0.02-0.07). The serum concentrations of periostin were particularly high in asthmatic patients complicated by chronic rhinosinusitis with nasal polyps and olfactory dysfunction. In contrast, neither atopic status, control status of asthma, nor quality of life were related with the "high-periostin" phenotype. CONCLUSION: Elevated periostin concentrations in serum were correlated with a specific phenotype of eosinophilic asthma, late-onset and often complicated by obstructive pulmonary dysfunction and nasal disorders.

A Phase II study of S-1 and irinotecan combination therapy in previously treated patients with advanced non-small cell lung cancer.

OBJECTIVE: This Phase II study was conducted to evaluate the efficacy and safety of S-1 and irinotecan combination therapy as a second-line treatment in patients with advanced non-small cell lung cancer. METHODS: Irinotecan was administered at 60 mg/m(2) on Days 1 and 8. Oral S-1 was administered on Days 1-14 every 3 weeks at 80 mg/day for patients with a body surface area of <1.25 m(2), 100 mg/day for patients with a body surface area of 1.25-1.5 m(2) and 120 mg/day for patients with a body surface area of >1.5 m(2). The primary endpoint was response rate, while the secondary endpoints were progression-free survival, overall survival and safety. RESULTS: Thirty-one patients were enrolled in this study. The response and disease control rates were 6.5 and 58.1%, respectively. Progression-free survival and median survival time were 2.8 and 12.6 months, respectively. Grade 3-4 adverse events were reported for 29.0% of the patients. Hematological toxicities of Grade 3 or 4 included leukopenia (9.7%), neutropenia (9.7%), febrile neutropenia (3.2%), thrombopenia (3.2%) and anemia (6.5%). Non-hematological toxicities of Grade 3 or 4 included pneumonitis (6.5%), diarrhea, colitis, dyspnea, rash, oral mucositis, anorexia and pulmonary thromboembolism/deep vein thrombosis (3.2% each). CONCLUSIONS: S-1 and irinotecan combination therapy at the present dose and schedule exhibited only modest efficacy with mild toxicities in previously treated patients with non-small cell lung cancer. No further clinical investigation with current dose and schedules is warranted for patients with non-small cell lung cancer who failed first-line platinum-based doublet chemotherapy.

Determinants of Long-Term Persistence with Tiotropium Bromide for Chronic Obstructive Pulmonary Disease.

Tiotropium bromide, a long-acting anticholinergic agent, improves pulmonary function and quality of life of patients suffering from chronic obstructive pulmonary disease (COPD). We retrospectively examined the factors that determine the long-term persistence with tiotropium bromide. Among 6,301 patients who underwent pulmonary function tests in our pulmonary clinic between 2006 and 2009, 644 met the following criteria: 1) age > 40 years, 2) ≥ 20 pack-years smoking history, and 3) forced expiratory volume in 1 sec / forced vital capacity ratio < 0.7. The clinical information, including the prescription of tiotropium, was obtained from the patients' records. Tiotropium was administered to 255 patients (40%), of whom 48 (19%) discontinued treatment within 1 year, and 65 (25%) discontinued treatment within the median observation period of 32 months. The drug was discontinued because of ineffectiveness in 35 patients (73%), and because of adverse drug effects in 13 patients (27%). Young age, current smoking, absence of respiratory symptoms alleviation, and less severe disease characterized by a) mild airflow limitation, b) mild to moderate emphysema, or c) no exacerbation of COPD during the 1(st) year of treatment were predictors of drug discontinuation.