RESUMO
Chronic infection with Schistosoma mansoni parasites is associated with reduced allergic sensitization in humans, while schistosome eggs protects against allergic airway inflammation (AAI) in mice. One of the main secretory/excretory molecules from schistosome eggs is the glycosylated T2-RNAse Omega-1 (ω1). We hypothesized that ω1 induces protection against AAI during infection. Peritoneal administration of ω1 prior to sensitization with Ovalbumin (OVA) reduced airway eosinophilia and pathology, and OVA-specific Th2 responses upon challenge, independent from changes in regulatory T cells. ω1 was taken up by monocyte-derived dendritic cells, mannose receptor (CD206)-positive conventional type 2 dendritic cells (CD206+ cDC2), and by recruited peritoneal macrophages. Additionally, ω1 impaired CCR7, F-actin, and costimulatory molecule expression on myeloid cells and cDC2 migration in and ex vivo, as evidenced by reduced OVA+ CD206+ cDC2 in the draining mediastinal lymph nodes (medLn) and retainment in the peritoneal cavity, while antigen processing and presentation in cDC2 were not affected by ω1 treatment. Importantly, RNAse mutant ω1 was unable to reduce AAI or affect DC migration, indicating that ω1 effects are dependent on its RNAse activity. Altogether, ω1 hampers migration of OVA+ cDC2 to the draining medLn in mice, elucidating how ω1 prevents allergic airway inflammation in the OVA/alum mouse model.
RESUMO
BACKGROUND: Asthma is often accompanied by type 2 immunity rich in IL-4, IL-5 and IL-13 cytokines produced by TH2 lymphocytes or type 2 innate lymphoid cells (ILC2s). Interleukin-2 family cytokines play a key role in the differentiation, homeostasis and effector function of innate and adaptive lymphocytes. OBJECTIVE: IL-9 and IL-21 boost the activation and proliferation of TH2 and ILC2s, but the relative importance and potential synergism between these γc cytokines is currently unknown. METHODS: Using newly generated antibodies, we inhibited IL-9 and IL-21 alone or in combination, in various murine models of asthma. In a translational approach using segmental allergen challenge, we recently described elevated IL-9 levels in human allergic asthmatics in comparison to non-asthmatic controls. Here, we also measured IL-21 in both groups. RESULTS: IL-9 played a central role in controlling innate IL-33 induced lung inflammation by promoting proliferation and activation of ILC2s, in an IL-21 independent manner. Conversely, chronic house dust mite induced airway inflammation, mainly driven by adaptive immunity, was solely dependent on IL-21, that controlled TH2 activation, eosinophilia, total serum IgE and formation of tertiary lymphoid structures. In a model of innate on adaptive immunity driven by papain allergen, a clear synergy was found between both pathways, since combined anti-IL-9 or anti-IL-21 blockade was superior in reducing key asthma features. In human bronchoalveolar lavage (BAL) samples we measured elevated IL-21 protein within the allergic asthmatic group, compared with the allergic control group. We also found increased IL21R transcripts and predicted IL-21 ligand activity in various disease-associated cell subsets. CONCLUSION: IL-9 and IL-21 play important and non-redundant roles in allergic asthma by boosting ILC2s and TH2 cells, revealing a dual IL-9 and IL-21 targeting strategy as a new and testable approach.
RESUMO
Respiratory viral infections represent one of the major causes of death worldwide. The recent coronavirus disease 2019 pandemic alone claimed the lives of over 6 million people around the globe. It is therefore crucial to understand how the immune system responds to these threats and how respiratory infection can be controlled and constrained. Dendritic cells (DCs) are one of the key players in antiviral immunity because of their ability to detect pathogens. They can orchestrate an immune response that will, in most cases, lead to viral clearance. Different subsets of DCs are present in the lung and each subset can contribute to antiviral responses through various mechanisms. In this review, we discuss the role of the different lung DC subsets in response to common respiratory viruses, with a focus on respiratory syncytial virus, influenza A virus and severe acute respiratory syndrome coronavirus 2. We also review how lung DC-mediated responses to respiratory viruses can lead to the worsening of an existing chronic pulmonary disease such as asthma. Throughout the review, we discuss results obtained from animal studies as well as results generated from infected patients.
Assuntos
Células Dendríticas , Infecções Respiratórias , Células Dendríticas/imunologia , Células Dendríticas/virologia , Humanos , Animais , Infecções Respiratórias/imunologia , Infecções Respiratórias/virologia , Pulmão/imunologia , Pulmão/virologia , Interações Hospedeiro-Patógeno , COVID-19/imunologia , Viroses/imunologia , Viroses/virologia , SARS-CoV-2/imunologia , SARS-CoV-2/patogenicidadeAssuntos
Asma , Imunoterapia Adotiva , Receptores de Antígenos Quiméricos , Asma/imunologia , Humanos , Receptores de Antígenos Quiméricos/imunologia , Receptores de Antígenos Quiméricos/genética , Imunoterapia Adotiva/métodos , Animais , Linfócitos T/imunologia , Camundongos , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos de Linfócitos T/metabolismoRESUMO
Sublingual allergen immunotherapy (SLIT) is an emerging treatment option for allergic asthma and a potential disease-modifying strategy for asthma prevention. The key cellular events leading to such long-term tolerance remain to be fully elucidated. We administered prophylactic SLIT in a mouse model of house dust mite (HDM)-driven allergic asthma. HDM extract was sublingually administered over 3 weeks followed by intratracheal sensitization and intranasal challenges with HDM. Prophylactic SLIT prevented allergic airway inflammation and hyperreactivity with a low lab-to-lab variation. The HDM-specific T helper (Th)2 (cluster of differentiation 4 Th) response was shifted by SLIT toward a regulatory and Th17 response in the lung and mediastinal lymph node. By using Derp1-specific cluster of differentiation 4+ T cells (1-DER), we found that SLIT blocked 1-DER T cell recruitment to the mediastinal lymph node and dampened IL-4 secretion following intratracheal HDM sensitization. Sublingually administered Derp1 protein activated 1-DER T cells in the cervical lymph node via chemokine receptor7+ migratory dendritic cells (DC). DCs migrating from the oral submucosa to the cervical lymph node after SLIT-induced Foxp3+ regulatory T cells. When mice were sensitized with HDM, prior prophylactic SLIT increased Derp1 specific regulatory T cells (Tregs) and lowered Th2 recruitment in the lung. By using Foxp3-diphtheria toxin receptor mice, Tregs were found to contribute to the immunoregulatory prophylactic effect of SLIT on type 2 immunity. These findings in a mouse model suggest that DC-mediated functional Treg induction in oral mucosa draining lymph nodes is one of the driving mechanisms behind the disease-modifying effect of prophylactic SLIT.
Assuntos
Antígenos de Dermatophagoides , Asma , Células Dendríticas , Modelos Animais de Doenças , Fatores de Transcrição Forkhead , Pyroglyphidae , Imunoterapia Sublingual , Linfócitos T Reguladores , Células Th2 , Animais , Linfócitos T Reguladores/imunologia , Células Dendríticas/imunologia , Camundongos , Pyroglyphidae/imunologia , Fatores de Transcrição Forkhead/metabolismo , Antígenos de Dermatophagoides/imunologia , Asma/imunologia , Asma/terapia , Asma/prevenção & controle , Imunoterapia Sublingual/métodos , Células Th2/imunologia , Proteínas de Artrópodes/imunologia , Feminino , Alérgenos/imunologia , Alérgenos/administração & dosagem , Camundongos Endogâmicos BALB C , Humanos , Dessensibilização Imunológica/métodos , Cisteína Endopeptidases/imunologia , Cisteína Endopeptidases/metabolismoRESUMO
Spontaneous protein crystallization is a rare event, yet protein crystals are frequently found in eosinophil-rich inflammation. In humans, Charcot-Leyden crystals (CLCs) are made from galectin-10 (Gal10) protein, an abundant protein in eosinophils. Although mice do not encode Gal10 in their genome, they do form pseudo-CLCs, made from the chitinase-like proteins Ym1 and/or Ym2, encoded by Chil3 and Chil4 and made by myeloid and epithelial cells respectively. Here, we investigated the biological effects of pseudo-CLCs since their function is currently unknown. We produced recombinant Ym1 crystals which were shown to have identical crystal packing and structure by X-ray crystallography as in vivo native crystals derived from murine lung. When administered to the airways of mice, crystalline but not soluble Ym1 stimulated innate and adaptive immunity and acted as a type 2 immune adjuvant for eosinophilic inflammation via triggering of dendritic cells (DCs). Murine Ym1 protein crystals found at sites of eosinophilic inflammation reinforce type 2 immunity and could serve as a surrogate model for studying the biology of human CLCs.
Assuntos
Imunidade Adaptativa , Quitinases , Animais , Humanos , Camundongos , Adjuvantes Imunológicos , Cristalização , InflamaçãoRESUMO
Healthy adipose tissue (AT) contains ST2+ Tregs, ILC2s, and alternatively activated macrophages that are lost in mice or humans on high caloric diet. Understanding how this form of type 2 immunity is regulated could improve treatment of obesity. The STE20 kinase Thousand And One amino acid Kinase-3 (TAOK3) has been linked to obesity in mice and humans, but its precise function is unknown. We found that ST2+ Tregs are upregulated in visceral epididymal white AT (eWAT) of Taok3-/- mice, dependent on IL-33 and the kinase activity of TAOK3. Upon high fat diet feeding, metabolic dysfunction was attenuated in Taok3-/- mice. ST2+ Tregs disappeared from eWAT in obese wild-type mice, but this was not the case in Taok3-/- mice. Mechanistically, AT Taok3-/- Tregs were intrinsically more responsive to IL-33, through higher expression of ST2, and expressed more PPARγ and type 2 cytokines. Thus, TAOK3 inhibits adipose tissue Tregs and regulates immunometabolism under excessive caloric intake.
Assuntos
Imunidade Inata , Interleucina-33 , Animais , Humanos , Camundongos , Dieta Hiperlipídica/efeitos adversos , Proteína 1 Semelhante a Receptor de Interleucina-1 , Linfócitos/metabolismo , Camundongos Endogâmicos C57BL , Obesidade/metabolismoRESUMO
Despite the lack of endogenous chitin synthesis, mammalian genomes encode two enzymatically active true chitinases (chitotriosidase and acidic mammalian chitinase) and a variable number of chitinase-like proteins (CLPs) that have no enzyme activity but bind chitin. Chitinases and CLPs are prominent components of type-2 immune response-mediated respiratory diseases. However, despite extensive research into their role in allergic airway disease, there is still no agreement on whether they are mere biomarkers of disease or actual disease drivers. Functions ascribed to chitinases and CLPs include, but are not limited to host defense against chitin-containing pathogens, directly promoting inflammation, and modulating tissue remodeling and fibrosis. Here, we discuss in detail the chitin-dependent and -independent roles of chitinases and CLPs in the context of allergic airway disease, and recent advances and emerging concepts in the field that might identify opportunities for new therapies.
Assuntos
Asma , Quitinases , Hipersensibilidade , Animais , Humanos , Quitinases/metabolismo , Inflamação , Quitina/metabolismo , Mamíferos/metabolismoRESUMO
Over the last years, technological advances in the field of asthma have led to the identification of two disease endotypes, namely, type 2-high and type 2-low asthma, characterized by different pathophysiologic mechanisms at a cellular and molecular level. Although specific immune cells are important contributors to each of the recognized asthma endotype, the lung epithelium is now regarded as a crucial player able to orchestrate responses to inhaled environmental triggers such as allergens and microbes. The impact of the epithelium goes beyond its physical barrier. It is nowadays considered as a part of the innate immune system that can actively respond to insults. Activated epithelial cells, by producing a specific set of cytokines, trigger innate and adaptive immune cells to cause pathology. Here, we review how the epithelium contributes to the development of Th2 sensitization to allergens and asthma with a "type 2-high" signature, in both murine models and human studies of this asthma endotype. We also discuss epithelial responses to respiratory viruses, such as rhinovirus, respiratory syncytial virus, and SARS-CoV-2, and how these triggers influence not only asthma development but also asthma exacerbation. Finally, we also summarize the results of promising clinical trials using biologicals targeting epithelial-derived cytokines in asthmatic patients.
Assuntos
Asma , Humanos , Animais , Camundongos , Pulmão , Células Epiteliais , Citocinas , Epitélio , AlérgenosRESUMO
In the lungs, immune cells make contact with different antigens every day. This requires an adequate immune response. Dendritic cells (DCs) form a dense network in the respiratory mucosa and continuously sample inhaled allergens. They play an important role in bridging innate and adaptive immunity. DCs are classically divided into plasmacytoid DCs (pDCs) and conventional DCs (cDCs). cDCs in the steady-state are further subdivided into cDC1s and cDC2s based on their ontogeny and distinct non-redundant functions. Recently, a hyperactivated state of cDC2s has been described that arises during inflammation, coined inflammatory cDC2s (inf-cDC2s) that phenotypically mimics monocyte-derived cells and has a hybrid cDC1/macrophage functional identity. This chapter describes different enrichment methods and a fluorescence-activated cell sorting protocol that in combination allow for discrimination and isolation of pure DC subsets from the murine lung. The chapter represents an up-to-date, universal framework that can be adapted to other tissues and species which is an added value in intra- and interspecies comparative research.
Assuntos
Células Dendríticas , Pulmão , Imunidade Adaptativa , Alérgenos , Animais , Citometria de Fluxo/métodos , CamundongosRESUMO
A principal purpose of type 2 immunity was thought to be defense against large parasites, but it also functions in the restoration of homeostasis, such as toxin clearance following snake bites. In other cases, like allergy, the type 2 T helper (Th2) cytokines and cells present in the environment are detrimental and cause diseases. In recent years, the recognition of cell heterogeneity within Th2-associated cell populations has revealed specific functions of cells with a particular phenotype or gene signature. In addition, here we discuss the recent data regarding heterogeneity of type 2 immunity-related cells, as well as their newly identified role in a variety of processes ranging from involvement in respiratory viral infections [especially in the context of the recent COVID-19 (coronavirus disease 2019) pandemic] to control of cancer development or of metabolic homeostasis.
Assuntos
COVID-19 , Hipersensibilidade , Animais , Citocinas/metabolismo , Homeostase , Humanos , Linfócitos T Auxiliares-Indutores/metabolismo , Células Th2RESUMO
The causal signals and the relevance of group 2 innate lymphoid cell (ILC2) dynamic redistribution during inflammation remain unknown. In this issue of Immunity, Cautivo et al. show that type 2 immunity drives ILC2 accumulation at non-adventitial "parenchymal" sites, allowing balanced responses in inflamed tissues.
Assuntos
Imunidade Inata , Linfócitos , Humanos , Imunidade Inata/imunologia , Inflamação/imunologia , Linfócitos/imunologiaRESUMO
BACKGROUND: The most common endotype of asthma is type 2-high asthma, which is sometimes driven by adaptive allergen-specific TH2 lymphocytes that react to allergens presented by dendritic cells (DCs), or sometimes by an innate immune response dominated by type 2 innate lymphocytes (ILC2s). Understanding the underlying pathophysiology of asthma is essential to improve patient-tailored therapy. The STE20 kinase thousand-and-one kinase 3 (TAOK3) controls key features in the biology of DCs and lymphocytes, but to our knowledge, its potential usefulness as a target for asthma therapy has not yet been addressed. OBJECTIVE: We examined if and how loss of Taok3 affects the development of house dust mite (HDM)-driven allergic asthma in an in vivo mouse model. METHODS: Wild-type Taok3+/+ and gene-deficient Taok3-/- mice were sensitized and challenged with HDM, and bronchoalveolar lavage fluid composition, mediastinal lymph node cytokine production, lung histology, and bronchial hyperreactivity measured. Conditional Taok3fl/fl mice were crossed to tissue- and cell-specific specific deletor Cre mice to understand how Taok3 acted on asthma susceptibility. Kinase-dead (KD) Taok3KD mice were generated to probe for the druggability of this pathway. Activation of HDM-specific T cells was measured in adoptively transferred HDM-specific T-cell receptor-transgenic CD4+ T cells. ILC2 biology was assessed by in vivo and in vitro IL-33 stimulation assays in Taok3-/- and Taok3+/+, Taok3KD, and Red5-Cre Taok3fl/fl mice. RESULTS: Taok3-/- mice failed to mount salient features of asthma, including airway eosinophilia, TH2 cytokine production, IgE secretion, airway goblet cell metaplasia, and bronchial hyperreactivity compared to controls. This was due to intrinsic loss of Taok3 in hematopoietic and not epithelial cells. Loss of Taok3 resulted in hampered HDM-induced lung DC migration to the draining lymph nodes and defective priming of HDM-specific TH2 cells. Strikingly, HDM and IL-33-induced ILC2 proliferation and function were also severely affected in Taok3-deficient and Taok3KD mice. CONCLUSIONS: Absence of Taok3 or loss of its kinase activity protects from HDM-driven allergic asthma as a result of defects in both adaptive DC-mediated TH2 activation and innate ILC2 function. This identifies Taok3 as an interesting drug target, justifying further testing as a new treatment for type 2-high asthma.
Assuntos
Asma , Hiper-Reatividade Brônquica , Alérgenos , Animais , Hiper-Reatividade Brônquica/patologia , Citocinas , Dermatophagoides pteronyssinus , Modelos Animais de Doenças , Humanos , Imunidade Inata , Interleucina-33 , Pulmão , Linfócitos , Camundongos , Proteínas Serina-Treonina Quinases , Pyroglyphidae , Células Th2RESUMO
Group 3 innate lymphoid cells (ILC3s) critically regulate host-microbe interactions in the gastrointestinal tract, but their role in the airway remains poorly understood. Here, we demonstrate that lymphoid-tissue-inducer (LTi)-like ILC3s are enriched in the lung-draining lymph nodes of healthy mice and humans. These ILC3s abundantly express major histocompatibility complex class II (MHC class II) and functionally restrict the expansion of allergen-specific CD4+ T cells upon experimental airway challenge. In a mouse model of house-dust-mite-induced allergic airway inflammation, MHC class II+ ILC3s limit T helper type 2 (Th2) cell responses, eosinophilia, and airway hyperresponsiveness. Furthermore, MHC class II+ ILC3s limit a concomitant Th17 cell response and airway neutrophilia. This exacerbated Th17 cell response requires exposure of the lung to microbial stimuli, which can be found associated with house dust mites. These findings demonstrate a critical role for antigen-presenting ILC3s in orchestrating immune tolerance in the airway by restricting pro-inflammatory T cell responses to both allergens and microbes.
Assuntos
Linfócitos T CD4-Positivos/metabolismo , Imunidade Inata/imunologia , Linfócitos/fisiologia , Respiração/imunologia , Imunidade Adaptativa/imunologia , Alérgenos/imunologia , Animais , Asma/imunologia , Linfócitos T CD4-Positivos/imunologia , Citocinas/metabolismo , Feminino , Interações entre Hospedeiro e Microrganismos/fisiologia , Humanos , Inflamação/patologia , Pulmão/imunologia , Linfonodos/imunologia , Linfócitos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pyroglyphidae/imunologia , Hipersensibilidade Respiratória/imunologia , Células Th17/metabolismo , Células Th2/metabolismoAssuntos
Asma , Pyroglyphidae , Alérgenos , Animais , Asma/etiologia , Modelos Animais de Doenças , Humanos , Camundongos , MucoRESUMO
Regulation of epithelial cell death has emerged as a key mechanism controlling immune homeostasis in barrier surfaces. Necroptosis is a type of regulated necrotic cell death induced by receptor interacting protein kinase 3 (RIPK3) that has been shown to cause inflammatory pathologies in different tissues. The role of regulated cell death and particularly necroptosis in lung homeostasis and disease remains poorly understood. Here we show that mice with Airway Epithelial Cell (AEC)-specific deficiency of Fas-associated with death domain (FADD), an adapter essential for caspase-8 activation, developed exacerbated allergic airway inflammation in a mouse model of asthma induced by sensitization and challenge with house dust mite (HDM) extracts. Genetic inhibition of RIPK1 kinase activity by crossing to mice expressing kinase inactive RIPK1 as well as RIPK3 or MLKL deficiency prevented the development of exaggerated HDM-induced asthma pathology in FADDAEC-KO mice, suggesting that necroptosis of FADD-deficient AECs augmented the allergic immune response. These results reveal a role of AEC necroptosis in amplifying airway allergic inflammation and suggest that necroptosis could contribute to asthma exacerbations caused by respiratory virus infections inducing AEC death.
Assuntos
Alérgenos/imunologia , Asma/etiologia , Asma/metabolismo , Necroptose/imunologia , Pyroglyphidae/imunologia , Mucosa Respiratória/imunologia , Mucosa Respiratória/metabolismo , Remodelação das Vias Aéreas , Animais , Asma/patologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Biomarcadores , Modelos Animais de Doenças , Progressão da Doença , Suscetibilidade a Doenças , Ativação Enzimática , Proteína de Domínio de Morte Associada a Fas/deficiência , Imunoglobulina E/imunologia , Imuno-Histoquímica , Camundongos , Camundongos Knockout , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Receptores de Hidrocarboneto Arílico/metabolismo , Mucosa Respiratória/patologiaRESUMO
Protein crystals derived from innate immune cells have been synonymous with a Type-2 immune response in both mouse and man for over 150 years. Eosinophilic Galectin-10 (Charcot-Leyden) crystals in humans, and Ym1/Ym2 crystals in mice are frequently found in the context of parasitic infections, but also in diseases such as asthma and chronic rhinosinusitis. Despite their notable presence, these crystals are often overlooked as trivial markers of Type-2 inflammation. Here, we discuss the source, context, and role of protein crystallization. We focus on similarities observed between Galectin-10 and Ym1/2 crystals in driving immune responses; the subsequent benefit to the host during worm infection, and conversely the detrimental exacerbation of inflammation and mucus production during asthma.
Assuntos
Alérgenos/imunologia , Hipersensibilidade/etiologia , Imunidade , Proteínas/imunologia , Animais , Biomarcadores , Cristalinas/imunologia , Suscetibilidade a Doenças , Humanos , Hipersensibilidade/metabolismo , Mediadores da Inflamação/metabolismo , Camundongos , Especificidade de Órgãos/imunologia , Proteínas/químicaRESUMO
The spleen contains a myriad of conventional dendritic cell (cDC) subsets that protect against systemic pathogen dissemination by bridging antigen detection to the induction of adaptive immunity. How cDC subsets differentiate in the splenic environment is poorly understood. Here, we report that LTα1ß2-expressing Rorgt+ ILC3s, together with B cells, control the splenic cDC niche size and the terminal differentiation of Sirpα+CD4+Esam+ cDC2s, independently of the microbiota and of bone marrow pre-cDC output. Whereas the size of the splenic cDC niche depended on lymphotoxin signaling only during a restricted time frame, the homeostasis of Sirpα+CD4+Esam+ cDC2s required continuous lymphotoxin input. This latter property made Sirpα+CD4+Esam+ cDC2s uniquely susceptible to pharmacological interventions with LTßR agonists and antagonists and to ILC reconstitution strategies. Together, our findings demonstrate that LTα1ß2-expressing Rorgt+ ILC3s drive splenic cDC differentiation and highlight the critical role of ILC3s as perpetual regulators of lymphoid tissue homeostasis.