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
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
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
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
Chronic helminth infection with Schistosoma (S.) mansoni protects against allergic airway inflammation (AAI) in mice and is associated with reduced Th2 responses to inhaled allergens in humans, despite the presence of schistosome-specific Th2 immunity. Schistosome eggs strongly induce type 2 immunity and allow to study the dynamics of Th2 versus regulatory responses in the absence of worms. Treatment with isolated S. mansoni eggs by i.p. injection prior to induction of AAI to ovalbumin (OVA)/alum led to significantly reduced AAI as assessed by less BAL and lung eosinophilia, less cellular influx into lung tissue, less OVA-specific Th2 cytokines in lungs and lung-draining mediastinal lymph nodes and less circulating allergen-specific IgG1 and IgE antibodies. While OVA-specific Th2 responses were inhibited, treatment induced a strong systemic Th2 response to the eggs. The protective effect of S. mansoni eggs was unaltered in µMT mice lacking mature (B2) B cells and unaffected by Treg cell depletion using anti-CD25 blocking antibodies during egg treatment and allergic sensitization. Notably, prophylactic egg treatment resulted in a reduced influx of pro-inflammatory, monocyte-derived dendritic cells into lung tissue of allergic mice following challenge. Altogether, S. mansoni eggs can protect against the development of AAI, despite strong egg-specific Th2 responses.
Assuntos
Anticorpos Antiprotozoários/sangue , Asma/prevenção & controle , Óvulo/imunologia , Schistosoma mansoni/imunologia , Alérgenos/imunologia , Compostos de Alúmen/farmacologia , Animais , Anticorpos Antiprotozoários/imunologia , Asma/imunologia , Citocinas/imunologia , Modelos Animais de Doenças , Eosinofilia/prevenção & controle , Feminino , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Inflamação/patologia , Subunidade alfa de Receptor de Interleucina-2 , Pulmão/imunologia , Pulmão/parasitologia , Pulmão/patologia , Camundongos Endogâmicos C57BL , Ovalbumina/imunologia , Ovalbumina/farmacologia , Linfócitos T Reguladores/imunologia , Células Th2/imunologiaRESUMO
Helminth infections have been suggested to impair the development and outcome of Th1 responses to vaccines and intracellular microorganisms. However, there are limited data regarding the ability of intestinal nematodes to modulate Th1 responses at sites distal to the gut. In this study, we have investigated the effect of the intestinal nematode Heligmosomoides polygyrus bakeri on Th1 responses to Mycobacterium bovis bacillus Calmette-Guérin (BCG). We found that H. polygyrus infection localized to the gut can mute BCG-specific CD4(+) T cell priming in both the spleen and skin-draining lymph nodes. Furthermore, H. polygyrus infection reduced the magnitude of delayed-type hypersensitivity (DTH) to PPD in the skin. Consequently, H. polygyrus-infected mice challenged with BCG had a higher mycobacterial load in the liver compared with worm-free mice. The excretory-secretory product from H. polygyrus (HES) was found to dampen IFN-γ production by mycobacteria-specific CD4(+) T cells. This inhibition was dependent on the TGF-ßR signaling activity of HES, suggesting that TGF-ß signaling plays a role in the impaired Th1 responses observed coinfection with worms. Similar to results with mycobacteria, H. polygyrus-infected mice displayed an increase in skin parasite load upon secondary infection with Leishmania major as well as a reduction in DTH responses to Leishmania Ag. We show that a nematode confined to the gut can mute T cell responses to mycobacteria and impair control of secondary infections distal to the gut. The ability of intestinal helminths to reduce DTH responses may have clinical implications for the use of skin test-based diagnosis of microbial infections.
Assuntos
Coinfecção , Gastroenteropatias/imunologia , Infecções por Mycobacterium/imunologia , Infecções por Nematoides/imunologia , Animais , Antígenos de Bactérias/imunologia , Antígenos de Helmintos/imunologia , Movimento Celular/imunologia , Doença Crônica , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Modelos Animais de Doenças , Suscetibilidade a Doenças , Gastroenteropatias/microbiologia , Gastroenteropatias/parasitologia , Gastroenteropatias/patologia , Interações Hospedeiro-Parasita/imunologia , Interações Hospedeiro-Patógeno/imunologia , Ativação Linfocitária/imunologia , Camundongos , Camundongos Knockout , Infecções por Mycobacterium/microbiologia , Infecções por Mycobacterium/patologia , Mycobacterium bovis/imunologia , Infecções por Nematoides/parasitologia , Infecções por Nematoides/patologia , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Transdução de Sinais , Especificidade do Receptor de Antígeno de Linfócitos T/imunologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismoRESUMO
Helminth parasites control host-immune responses by secreting immunomodulatory glycoproteins. Clinical trials and mouse model studies have demonstrated the potential of helminth-derived glycoproteins for the treatment of immune-related diseases, like allergies and autoimmune diseases. Studies are however hampered by the limited availability of native parasite-derived proteins. Moreover, recombinant protein production systems have thus far been unable to reconstitute helminth-like glycosylation essential for the functionality of some helminth glycoproteins. Here we exploited the flexibility of the N-glycosylation machinery of plants to reconstruct the helminth glycoproteins omega-1 and kappa-5, two major constituents of immunomodulatory Schistosoma mansoni soluble egg antigens. Fine-tuning transient co-expression of specific glycosyltransferases in Nicotiana benthamiana enabled the synthesis of Lewis X (LeX) and LDN/LDN-F glycan motifs as found on natural omega-1 and kappa-5, respectively. In vitro and in vivo evaluation of the introduction of native LeX motifs on plant-produced omega-1 confirmed that LeX on omega-1 contributes to the glycoprotein's Th2-inducing properties. These data indicate that mimicking the complex carbohydrate structures of helminths in plants is a promising strategy to allow targeted evaluation of therapeutic glycoproteins for the treatment of inflammatory disorders. In addition, our results offer perspectives for the development of effective anti-helminthic vaccines by reconstructing native parasite glycoprotein antigens.
Assuntos
Glicoproteínas/imunologia , Proteínas de Helminto/imunologia , Nicotiana/imunologia , Schistosoma mansoni/imunologia , Animais , Anticorpos Anti-Helmínticos/genética , Anticorpos Anti-Helmínticos/imunologia , Anticorpos Anti-Helmínticos/metabolismo , Antígenos de Helmintos/genética , Antígenos de Helmintos/imunologia , Antígenos de Helmintos/metabolismo , Proteínas do Ovo/genética , Proteínas do Ovo/imunologia , Proteínas do Ovo/metabolismo , Expressão Gênica/imunologia , Engenharia Genética , Glicoproteínas/genética , Glicoproteínas/metabolismo , Glicosilação , Proteínas de Helminto/genética , Proteínas de Helminto/metabolismo , Imunomodulação/genética , Imunomodulação/imunologia , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Schistosoma mansoni/genética , Schistosoma mansoni/metabolismo , Nicotiana/genética , Nicotiana/metabolismo , Vacinas/imunologiaRESUMO
Allergic airway disease is a major global health burden, and novel treatment options are urgently needed. Numerous epidemiological and experimental studies suggest that certain helminths and bacteria protect against respiratory allergies. These microorganisms are strong regulators of the immune system, and various potential regulatory mechanisms by which they protect against allergic airway inflammation have been proposed. Whereas early studies addressed the beneficial effect of natural infections, the focus now shifts toward identifying the dominant protective molecules and exploring their efficacy in models of allergic airway disease. In this article, we will review the evidence for microbe-mediated protection from allergic airway disease, the potential modes of action involved and discuss advances as well as limitations in the translation of this knowledge into novel treatment strategies against allergic airway disease.