RESUMO
Systemic immune cell dynamics during coronavirus disease 2019 (COVID-19) are extensively documented, but these are less well studied in the (upper) respiratory tract, where severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replicates1-6. Here, we characterized nasal and systemic immune cells in individuals with COVID-19 who were hospitalized or convalescent and compared the immune cells to those seen in healthy donors. We observed increased nasal granulocytes, monocytes, CD11c+ natural killer (NK) cells and CD4+ T effector cells during acute COVID-19. The mucosal proinflammatory populations positively associated with peripheral blood human leukocyte antigen (HLA)-DRlow monocytes, CD38+PD1+CD4+ T effector (Teff) cells and plasmablasts. However, there was no general lymphopenia in nasal mucosa, unlike in peripheral blood. Moreover, nasal neutrophils negatively associated with oxygen saturation levels in blood. Following convalescence, nasal immune cells mostly normalized, except for CD127+ granulocytes and CD38+CD8+ tissue-resident memory T cells (TRM). SARS-CoV-2-specific CD8+ T cells persisted at least 2 months after viral clearance in the nasal mucosa, indicating that COVID-19 has both transient and long-term effects on upper respiratory tract immune responses.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Nasofaringe/imunologia , Nariz/citologia , Mucosa Respiratória/imunologia , SARS-CoV-2/imunologia , Anticorpos Antivirais/sangue , COVID-19/imunologia , COVID-19/patologia , Granulócitos/imunologia , Antígenos HLA-DR/metabolismo , Humanos , Células Matadoras Naturais/imunologia , Células T de Memória/imunologia , Monócitos/imunologia , Nasofaringe/citologia , Nasofaringe/virologia , Neutrófilos/imunologia , Nariz/imunologia , Nariz/virologia , Estudos Prospectivos , Mucosa Respiratória/citologia , Mucosa Respiratória/virologiaRESUMO
Helminths are extraordinarily successful parasites due to their ability to modulate the host immune response. They have evolved a spectrum of immunomodulatory molecules that are now beginning to be defined, heralding a molecular revolution in parasite immunology. These discoveries have the potential both to transform our understanding of parasite adaptation to the host and to develop possible therapies for immune-mediated disease. In this review we will summarize the current state of the art in parasite immunomodulation and discuss perspectives on future areas for research and discovery.
Assuntos
Helmintíase/imunologia , Helmintos/imunologia , Interações Hospedeiro-Parasita , Imunomodulação , Imunidade Adaptativa , Animais , Evolução Biológica , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Helmintíase/parasitologia , Humanos , Imunidade Inata , Macrófagos/imunologia , Macrófagos/metabolismoRESUMO
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.
Assuntos
Movimento Celular , Células Dendríticas , Ovalbumina , Schistosoma mansoni , Animais , Camundongos , Ovalbumina/imunologia , Células Dendríticas/imunologia , Schistosoma mansoni/imunologia , Esquistossomose mansoni/imunologia , Feminino , Camundongos Endogâmicos C57BL , Hipersensibilidade Respiratória/imunologia , Hipersensibilidade Respiratória/prevenção & controle , Hipersensibilidade Respiratória/parasitologia , Células Th2/imunologia , Inflamação/imunologiaRESUMO
B-cells play a critical role in the formation of immune responses against pathogens by acting as antigen-presenting cells, by modulating immune responses and by generating immune memory and antibody responses. Here, we studied B-cell subset distributions between regions with higher and lower microbial exposure, i.e. by comparing peripheral blood B-cells from people living in Indonesia or Ghana to those from healthy Dutch residents using a 36-marker mass cytometry panel. By applying an unbiased multidimensional approach, we observed differences in the balance between the naïve and memory compartments, with higher CD11c+ and double negative (DN-IgDnegCD27neg) memory (M)B-cells in individuals from rural tropical areas, and conversely lower naïve B-cells compared to residents from an area with less pathogen exposure. Furthermore, characterization of total B-cell populations, CD11c+, DN and Breg cells showed the emergence of specific memory clusters in individuals living in rural tropical areas. Some of these differences were more pronounced in children compared to adults and suggest that a higher microbial exposure accelerates memory B cell formation, which 'normalizes' with age.
RESUMO
Professional antigen-presenting cells (APCs), like macrophages (MÏs) and dendritic cells (DCs), are central players in the induction of natural and vaccine-induced immunity to malaria, yet very little is known about the interaction of SPZ with human APCs. Intradermal delivery of whole-sporozoite vaccines reduces their effectivity, possibly due to dermal immunoregulatory effects. Therefore, understanding these interactions could prove pivotal to malaria vaccination. We investigated human APC responses to recombinant circumsporozoite protein (recCSP), SPZ and anti-CSP opsonized SPZ both in monocyte derived MoDCs and MoMÏs. Both MoDCs and MoMÏs readily took up recCSP but did not change phenotype or function upon doing so. SPZ are preferentially phagocytosed by MoMÏs instead of DCs and phagocytosis greatly increased after opsonization. Subsequently MoMÏs show increased surface marker expression of activation markers as well as tolerogenic markers such as Programmed Death-Ligand 1 (PD-L1). Additionally they show reduced motility, produce interleukin 10 and suppressed interferon gamma (IFNγ) production by antigen specific CD8+ T cells. Importantly, we investigated phenotypic responses to SPZ in primary dermal APCs isolated from human skin explants, which respond similarly to their monocyte-derived counterparts. These findings are a first step in enhancing our understanding of pre-erythrocytic natural immunity and the pitfalls of intradermal vaccination-induced immunity.
Assuntos
Células Apresentadoras de Antígenos/imunologia , Macrófagos/imunologia , Malária/imunologia , Plasmodium berghei/imunologia , Proteínas de Protozoários/imunologia , Pele/imunologia , Esporozoítos/imunologia , Animais , Células Cultivadas , Feminino , Humanos , Macrófagos/parasitologia , Malária/parasitologia , Camundongos , Pele/parasitologiaRESUMO
Asthma is a complex disease that often starts in childhood. Genomic and environmental factors as well as aberrant immune maturation early in life can contribute to the onset of disease, with great disparity over time and geographical regions. Epidemiological studies have scrutinised environmental exposures and attempted to translate these exposures into prevention strategies. Some approaches for patients with asthma have been successful (eg, smoking ban, the Finnish Asthma Programme), and primary prevention of wheeze in pre-school children (age 0-5 years) by the supplementation of vitamin D or fish oil, or both, to pregnant women seems promising. Several recent prevention initiatives are based on strong asthma-protective environmental microbial exposures associated with traditional rural lifestyles. Preclinical studies with various bacterial lysates, bacterial and dietary metabolites, or helminthic compounds have yielded promising results that await translation into clinical practice. Given the immense societal and individual burden of asthma, there is an urgent need to further develop novel strategies to eradicate the disease.
Assuntos
Asma/epidemiologia , Asma/prevenção & controle , Prevenção Primária/métodos , Asma/dietoterapia , Asma/imunologia , Pré-Escolar , Suplementos Nutricionais/provisão & distribuição , Exposição Ambiental/efeitos adversos , Feminino , Finlândia/epidemiologia , Óleos de Peixe/administração & dosagem , Óleos de Peixe/provisão & distribuição , Humanos , Lactente , Recém-Nascido , Masculino , Gravidez , Prevalência , Fatores de Proteção , Fatores de Risco , Prevenção do Hábito de Fumar/métodos , Vitamina D/administração & dosagem , Vitamina D/provisão & distribuiçãoRESUMO
Parasitic helminths evade, skew and dampen human immune responses through numerous mechanisms. Such effects will likely have consequences for HIV-1 transmission and disease progression. Here we analyzed the effects that soluble egg antigen (SEA) from Schistosoma mansoni had on modulating HIV-1 infection and cytokine/chemokine production in vitro. We determined that SEA, specifically through kappa-5, can potently bind to DC-SIGN and thereby blocks DC-SIGN mediated HIV-1 trans-infection (p<0.05) whilst not interfering with cis-infection. DCs exposed to SEA whilst maturing under Th2 promoting conditions, will upon co-culture with naïve T-cells induce a T-cell population that was less susceptible to HIV-1 R5 infection (p<0.05) compared to DCs unexposed to SEA, whereas HIV-1 X4 virus infection was unaffected. This was not observed for DCs exposed to SEA while maturing under Th1 or Th1/Th2 (Tmix) promoting conditions. All T-cell populations induced by SEA exposed DCs demonstrate a reduced capacity to produce IFN-γ and MIP-1ß. The infection profile of T-cells infected with HIV-1 R5 was not associated with down-modulation of CCR5 cell surface expression. We further show that DCs maturing under Tmix conditions exposed to plant recombinant omega-1 protein (rω-1), which demonstrates similar functions to natural ω-1, induced T-cell populations that were less sensitive for HIV-1 R5 infection (p<0.05), but not for X4 virus infection. This inhibition associated again with a reduction in IFN-γ and MIP-1ß expression, but additionally correlated with reduced CCR5 expression. We have shown that SEA parasite antigens and more specifically rω-1 can modulate HIV-1 infectivity with the potential to influence disease course in co-infected individuals.
Assuntos
Anticorpos Anti-Helmínticos/imunologia , Antígenos de Helmintos/imunologia , Proteínas do Ovo/imunologia , Infecções por HIV/metabolismo , Animais , Anticorpos Anti-Helmínticos/metabolismo , Antígenos de Helmintos/metabolismo , Linfócitos T CD4-Positivos/imunologia , Citocinas/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Proteínas do Ovo/metabolismo , Infecções por HIV/imunologia , Infecções por HIV/prevenção & controle , HIV-1/imunologia , Humanos , Ativação Linfocitária , Receptores CCR5/metabolismo , Schistosoma mansoni/metabolismo , Linfócitos T Auxiliares-Indutores/imunologia , Replicação Viral/imunologiaRESUMO
BACKGROUND: Asthma-like symptoms in preschool children, such as wheezing and dyspnea, are common time- and resource-consuming diagnostic and management challenges. Quality of wheezing and asthma recommendations varies. The purpose of this study, carried out by the European Academy of Allergy and Clinical Immunology (EAACI) Task Force for Preschool Wheeze, was to systematically review and assess the quality of guidelines for diagnosis and treatment of preschool wheezing and/or asthma. METHODS: The Cochrane Library, MEDLINE, and EMBASE were searched until June 2018. The methodological rigor, quality, and transparency of relevant guidelines were assessed with the use of the Appraisal of Guidelines for Research and Evaluation (AGREE II) tool. RESULTS: We identified 26 guidelines. The quality scores for each domain varied. Of all domains, clarity and presentation had the highest mean score, whereas applicability and stakeholder involvement had the lowest. The scores (median) for individual domains were as follows: score and purpose 86%; stakeholder involvement 49%; rigor of development 54%; clarity of presentation 85%; applicability 51%; and editorial independence 63%. CONCLUSION: Although several guidelines on asthma management in children are available, however, their quality varies. Additionally, there is a considerable gap in reliable recommendations on the management and treatment of non-asthmatic preschool wheeze.
Assuntos
Asma , Sons Respiratórios , Academias e Institutos , Asma/diagnóstico , Asma/terapia , Pré-Escolar , Humanos , Instituições AcadêmicasRESUMO
BACKGROUND: Although Schistosoma haematobium infection has been reported to be associated with alterations in immune function, in particular immune hyporesponsiveness, there have been only few studies that have used the approach of removing infection by drug treatment to establish this and to understand the underlying molecular mechanisms. METHODS: Schistosoma haematobium-infected schoolchildren were studied before and after praziquantel treatment and compared with uninfected controls. Cellular responses were characterized by cytokine production and flow cytometry, and in a subset of children RNA sequencing (RNA-Seq) transcriptome profiling was performed. RESULTS: Removal of S haematobium infection resulted in increased schistosome-specific cytokine responses that were negatively associated with CD4+CD25+FOXP3+ T-cells and accompanied by increased frequency of effector memory T-cells. Innate responses to Toll like receptor (TLR) ligation decreased with treatment and showed positive association with CD4+CD25+FOXP3+ T-cells. At the transcriptome level, schistosome infection was associated with enrichment in cell adhesion, whereas parasite removal was associated with a more quiescent profile. Further analysis indicated that alteration in cellular energy metabolism was associated with S haematobium infection and that the early growth response genes 2 and 3 (EGR 2 and EGR3), transcription factors that negatively regulate T-cell activation, may play a role in adaptive immune hyporesponsiveness. CONCLUSIONS: Using a longitudinal study design, we found contrasting effects of schistosome infection on innate and adaptive immune responses. Whereas the innate immune system appears more activated, the adaptive immunity is in a hyporesponsive state reflected in alterations in CD4+CD25+FOXP3+ T-cells, cellular metabolism, and transcription factors involved in anergy.
Assuntos
Anti-Helmínticos/uso terapêutico , Citocinas/imunologia , Praziquantel/uso terapêutico , Esquistossomose Urinária/imunologia , Transcriptoma , Imunidade Adaptativa , Animais , Criança , Feminino , Citometria de Fluxo , Gabão/epidemiologia , Humanos , Imunidade Inata , Estudos Longitudinais , Masculino , RNA-Seq , Esquistossomose Urinária/tratamento farmacológicoRESUMO
The helminth Schistosoma mansoni (S. mansoni) induces a network of regulatory immune cells, including interleukin (IL)-10-producing regulatory B cells (Bregs). However, the signals required for the development and activation of Bregs are not well characterized. Recent reports suggest that helminths induce type I interferons (IFN-I), and that IFN-I drive the development of Bregs in humans. We therefore assessed the role of IFN-I in the induction of Bregs by S. mansoni. Mice chronically infected with S. mansoni or i.v. injected with S. mansoni soluble egg antigen (SEA) developed a systemic IFN-I signature. Recombinant IFN-α enhanced IL-10 production by Bregs stimulated with S. mansoni SEA in vitro, while not activating Bregs by itself. IFN-I signaling also supported ex vivo IL-10 production by SEA-primed Bregs but was dispensable for activation of S. mansoni egg-induced Bregs in vivo. These data indicate that although IFN-I can serve as a coactivator for Breg IL-10 production, they are unlikely to participate in the development of Bregs in response to S. mansoni eggs.
Assuntos
Linfócitos B Reguladores/imunologia , Interferon Tipo I/metabolismo , Schistosoma mansoni/fisiologia , Esquistossomose mansoni/imunologia , Animais , Antígenos de Helmintos/imunologia , Células Cultivadas , Modelos Animais de Doenças , Ovos , Feminino , Citometria de Fluxo , Humanos , Interleucina-10/metabolismo , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Transdução de SinaisRESUMO
Chronic respiratory diseases are highly prevalent worldwide and will continue to rise in the foreseeable future. Despite intensive efforts over recent decades, the development of novel and effective therapeutic approaches has been slow. However, there is new and increasing evidence that communities of micro-organisms in our body, the human microbiome, are crucially involved in the development and progression of chronic respiratory diseases. Understanding the detailed mechanisms underlying this cross-talk between host and microbiota is critical for development of microbiome- or host-targeted therapeutics and prevention strategies. Here we review and discuss the most recent knowledge on the continuous reciprocal interaction between the host and microbes in health and respiratory disease. Furthermore, we highlight promising developments in microbiome-based therapies and discuss the need to employ more holistic approaches of restoring both the pulmonary niche and the microbial community.
Assuntos
Pneumopatias , Microbiota , Transtornos Respiratórios , Doenças Respiratórias , Humanos , Pulmão , Pneumopatias/terapiaRESUMO
Epidemiological and experimental studies have shown that exposure to the gastric bacterium Helicobacter pylori, especially in early life, prevents the development of asthma. Recent mouse studies have shown that this protective effect does not require live bacteria and that treatment with an extract of H. pylori in neonates prevents the development of airway inflammation and goblet cell metaplasia. In the current study, the effect of administration of an extract of H. pylori was assessed in a therapeutic study design with application of the extract just prior to allergen challenge. C57BL/6 mice were sensitized and challenged with OVA or house dust mite. Treatment with H. pylori extract just prior to the challenge significantly reduced airway inflammation, as assessed in bronchoalveolar lavage fluid and lung tissue, and reduced airway remodeling, as assessed by goblet cell quantification. These effects were apparent in the OVA model and in the house dust mite model. Injection of H. pylori extract reduced the processing of allergen by dendritic cells in the lungs and mediastinal lymph node. Bone marrow-derived dendritic cells exposed to H. pylori extract were affected with regard to their ability to process Ag. These data show that application of H. pylori extract after sensitization effectively inhibits allergic airway disease.
Assuntos
Alérgenos/imunologia , Asma/imunologia , Helicobacter pylori/imunologia , Hipersensibilidade/imunologia , Hipersensibilidade Respiratória/imunologia , Animais , Líquido da Lavagem Broncoalveolar/imunologia , Células Dendríticas/imunologia , Feminino , Células Caliciformes/imunologia , Inflamação/imunologia , Pulmão/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Ovalbumina/imunologia , Pyroglyphidae/imunologiaRESUMO
Infection with the helminth Schistosoma (S.) mansoni drives the development of interleukin (IL)-10-producing regulatory B (Breg) cells in mice and man, which have the capacity to reduce experimental allergic airway inflammation and are thus of high therapeutic interest. However, both the involved antigen and cellular mechanisms that drive Breg cell development remain to be elucidated. Therefore, we investigated whether S. mansoni soluble egg antigens (SEA) directly interact with B cells to enhance their regulatory potential, or act indirectly on B cells via SEA-modulated macrophage subsets. Intraperitoneal injections of S. mansoni eggs or SEA significantly upregulated IL-10 and CD86 expression by marginal zone B cells. Both B cells as well as macrophages of the splenic marginal zone efficiently bound SEA in vivo, but macrophages were dispensable for Breg cell induction as shown by macrophage depletion with clodronate liposomes. SEA was internalized into acidic cell compartments of B cells and induced a 3-fold increase of IL-10, which was dependent on endosomal acidification and was further enhanced by CD40 ligation. IPSE/alpha-1, one of the major antigens in SEA, was also capable of inducing IL-10 in naïve B cells, which was reproduced by tobacco plant-derived recombinant IPSE. Other major schistosomal antigens, omega-1 and kappa-5, had no effect. SEA depleted of IPSE/alpha-1 was still able to induce Breg cells indicating that SEA contains more Breg cell-inducing components. Importantly, SEA- and IPSE-induced Breg cells triggered regulatory T cell development in vitro. SEA and recombinant IPSE/alpha-1 also induced IL-10 production in human CD1d+ B cells. In conclusion, the mechanism of S. mansoni-induced Breg cell development involves a direct targeting of B cells by SEA components such as the secretory glycoprotein IPSE/alpha-1.
Assuntos
Linfócitos B Reguladores/imunologia , Proteínas do Ovo/imunologia , Proteínas de Helminto/imunologia , Óvulo/imunologia , Schistosoma mansoni/imunologia , Esquistossomose mansoni/imunologia , Animais , Antígenos de Helmintos/genética , Antígenos de Helmintos/imunologia , Proteínas do Ovo/genética , Feminino , Proteínas de Helminto/genética , Humanos , Interleucina-10/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Schistosoma mansoni/genética , Esquistossomose mansoni/genética , Esquistossomose mansoni/parasitologiaRESUMO
Current data indicate that the "bronchiolitis" diagnosis comprises more than one condition. Clinically, pathophysiologically, and even genetically three main clusters of patients can be identified among children suffering from severe bronchiolitis (or first wheezing episode): (a) respiratory syncytial virus (RSV)-induced bronchiolitis, characterized by young age of the patient, mechanical obstruction of the airways due to mucus and cell debris, and increased risk of recurrent wheezing. For this illness, an effective prophylactic RSV-specific monoclonal antibody is available; (b) rhinovirus-induced wheezing, associated with atopic predisposition of the patient and high risk of subsequent asthma development, which may, however, be reversed with systemic corticosteroids in those with severe illness; and (c) wheeze due to other viruses, characteristically likely to be less frequent and severe. Clinically, it is important to distinguish between these partially overlapping patient groups as they are likely to respond to different treatments. It appears that the first episode of severe bronchiolitis in under 2-year-old children is a critical event and an important opportunity for designing secondary prevention strategies for asthma. As data have shown bronchiolitis cannot simply be diagnosed using a certain cutoff age, but instead, as we suggest, using the viral etiology as the differentiating factor.
Assuntos
Bronquiolite/diagnóstico , Bronquiolite/tratamento farmacológico , Corticosteroides/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Bronquiolite/etiologia , Bronquiolite/virologia , Criança , Pré-Escolar , Humanos , Sons Respiratórios/etiologia , Vírus Sinciciais Respiratórios , RhinovirusAssuntos
Asma , Rinite Alérgica , Humanos , Alérgenos , Rinite Alérgica/terapia , Asma/terapia , Dessensibilização ImunológicaRESUMO
BACKGROUND: An inverse relation between Helicobacter pylori infection and asthma has been shown in epidemiological studies. Infection with H. pylori, or application of an extract of it before or after sensitization, inhibits allergic airway disease in mice. OBJECTIVES: The aim of this study was to investigate the effect of an extract of H. pylori on allergic airway disease induced by repeated allergen exposure in mice that were sensitized and challenged prior to extract application. METHOD: C57BL/6 mice were intranasally (i.n.) sensitized and challenged with house dust mite (HDM). After a minimum of 4 weeks, mice received the H. pylori extract intraperitoneally and were rechallenged i.n. with HDM. Allergen-specific antibodies were measured by ELISA. Cells present in the bronchoalveolar lavage fluid and dendritic cell (DC) subsets in the lung tissue were analyzed by flow cytometry. Tissue inflammation and goblet cell hyperplasia were assessed by histology. Cells of the mediastinal lymph node (mLN) were isolated and in vitro restimulated with HDM or H. pylori extract. RESULTS: Treatment with H. pylori extract before rechallenge reduced allergen-specific IgE, the DC numbers in the tissue, and goblet cell hyperplasia. Cells isolated from mLN of mice treated with the extract produced significantly more IL-10 and IL-17 after in vitro restimulation with HDM. mLN cells of H. pylori-treated mice that were re-exposed to the H. pylori extract produced significantly more interferon gamma. CONCLUSIONS: An extract of H. pylori is effective in reducing mucus production and various features of inflammation in HDM rechallenged mice.
Assuntos
Alérgenos/imunologia , Antígenos de Bactérias/imunologia , Células Caliciformes/patologia , Infecções por Helicobacter/complicações , Infecções por Helicobacter/imunologia , Helicobacter pylori/imunologia , Hipersensibilidade Respiratória/imunologia , Hipersensibilidade Respiratória/patologia , Animais , Biomarcadores , Biópsia , Citocinas/metabolismo , Exposição Ambiental , Feminino , Infecções por Helicobacter/microbiologia , Hiperplasia , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Imunofenotipagem , Camundongos , Pyroglyphidae/imunologiaRESUMO
Type 2 immune responses are most commonly associated with allergy and helminth parasite infections. Since the discovery of Th1 and Th2 immune responses more than 30 years ago, models of both allergic disease and helminth infections have been useful in characterizing the development, effector mechanisms and pathological consequences of type 2 immune responses. The observation that some helminth infections negatively correlate with allergic and inflammatory disease led to a large field of research into parasite immunomodulation. However, it is worth noting that helminth parasites are not always benign infections, and that helminth immunomodulation can have stimulatory as well as suppressive effects on allergic responses. In this review, we will discuss how parasitic infections change host responses, the consequences for bystander immunity and how this interaction influences clinical symptoms of allergy.
Assuntos
Helmintíase/imunologia , Helmintos/imunologia , Hipersensibilidade/imunologia , Animais , Helmintíase/parasitologia , Helmintos/genética , Humanos , Hipersensibilidade/parasitologia , Hipersensibilidade/terapia , ImunomodulaçãoRESUMO
To accelerate the development of novel vaccines for schistosomiasis, we set out to develop a human model for Schistosoma mansoni infection in healthy volunteers. During natural infections, female schistosomes produce eggs that give rise to morbidity. Therefore, we produced single-sex, male Schistosoma mansoni cercariae for human infection without egg production and associated pathology. Cercariae were produced in their intermediate snail hosts in accordance with the principles of good manufacturing practice (GMP). The application of GMP principles to an unconventional production process is a showcase for the controlled production of complex live challenge material in the European Union or under Food and Drug Administration guidance.