RESUMO
Despite increased appreciation for the role of nicotinic receptors in the modulation of and response to inflammation, the contribution of muscarinic receptors to mucosal homeostasis, clearance of enteric pathogens, and modulation of immune cell function remains relatively undefined. Uninfected and Nippostrongylus brasiliensis-infected wild-type and type 3 muscarinic receptor (M3R)-deficient (Chrm3(-/-)) mice were studied to determine the contribution of M3R to mucosal homeostasis as well as host defense against the TH2-eliciting enteric nematode N. brasiliensis Intestinal permeability and expression of TH1/TH17 cytokines were increased in uninfected Chrm3(-/-) small intestine. Notably, in Chrm3(-/-) mice infected with N. brasiliensis, small intestinal upregulation of TH2 cytokines was attenuated and nematode clearance was delayed. In Chrm3(-/-) mice, TH2-dependent changes in small intestinal function including smooth muscle hypercontractility, increased epithelial permeability, decreased epithelial secretion and absorption, and goblet cell expansion were absent despite N. brasiliensis infection. These findings identify an important role for M3R in host defense and clearance of N. brasiliensis, and support the expanding role of cholinergic muscarinic receptors in maintaining mucosal homeostasis.
Assuntos
Citocinas/metabolismo , Imunidade nas Mucosas , Mucosa Intestinal/metabolismo , Intestino Delgado/metabolismo , Nippostrongylus/patogenicidade , Receptor Muscarínico M3/metabolismo , Infecções por Strongylida/metabolismo , Células Th2/metabolismo , Animais , Células Cultivadas , Citocinas/imunologia , Modelos Animais de Doenças , Predisposição Genética para Doença , Homeostase , Interações Hospedeiro-Patógeno , Mucosa Intestinal/imunologia , Mucosa Intestinal/parasitologia , Intestino Delgado/imunologia , Intestino Delgado/parasitologia , Ativação de Macrófagos , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/parasitologia , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Nippostrongylus/imunologia , Fenótipo , Receptor Muscarínico M3/deficiência , Receptor Muscarínico M3/genética , Infecções por Strongylida/genética , Infecções por Strongylida/imunologia , Infecções por Strongylida/parasitologia , Células Th2/imunologia , Células Th2/parasitologia , Fatores de TempoRESUMO
Nippostrongylus brasiliensis infections generate pulmonary pathologies that can be associated with strong T(H)2 polarization of the host's immune response. We present data demonstrating N. brasiliensis-driven airway mucus production to be dependent on smooth muscle cell interleukin 4 receptor-α (IL-4Rα) responsiveness. At days 7 and 10 post infection (PI), significant airway mucus production was found in IL-4Rα(-/lox) control mice, whereas global knockout (IL-4Rα(-/-)) and smooth muscle-specific IL-4Rα-deficient mice (SM-MHC(Cre) IL-4Rα(-/lox)) showed reduced airway mucus responses. Furthermore, interleukin (IL)-13 and IL-5 cytokine production in SM-MHC(Cre) IL-4Rα(-/lox) mice was impaired along with a transient reduction in T-cell numbers in the lung. In vitro treatment of smooth muscle cells with secreted N. brasiliensis excretory-secretory antigen (NES) induced IL-6 production. Decreased protein kinase C (PKC)-dependent smooth muscle cell proliferation associated with cell cycle arrest was found in cells stimulated with NES. Together, these data demonstrate that both IL-4Rα and NES-driven responses by smooth muscle cells make important contributions in initiating T(H)2 responses against N. brasiliensis infections.
Assuntos
Subunidade alfa de Receptor de Interleucina-4/imunologia , Pneumopatias Parasitárias/imunologia , Miócitos de Músculo Liso/imunologia , Miócitos de Músculo Liso/metabolismo , Nippostrongylus/imunologia , Infecções por Strongylida/imunologia , Células Th2/imunologia , Animais , Ciclo Celular/genética , Citometria de Fluxo , Interleucina-13/biossíntese , Interleucina-13/imunologia , Subunidade alfa de Receptor de Interleucina-4/genética , Subunidade alfa de Receptor de Interleucina-4/metabolismo , Interleucina-5/biossíntese , Interleucina-5/imunologia , Interleucina-6/biossíntese , Interleucina-6/imunologia , Pneumopatias Parasitárias/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Muco/metabolismo , Nippostrongylus/patogenicidade , Proteína Quinase C/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Infecções por Strongylida/patologiaRESUMO
Nematode infections induce the upregulation of mucin- and glycosylation-related genes in intestinal epithelial cells in vivo. However, the factor(s) that induce these changes in epithelial cells have not been fully elucidated. In the present study, we analysed the effects of the Th2 cytokines IL-4 and IL-13 and the excretory-secretory (ES) product of the nematode Nippostrongylus brasiliensis on the gene expression of the major mucin core peptide MUC2, the sialyltransferase ST3GalIV (Siat4c) and the sulphotransferase HS3ST1 in intestinal epithelium-derived IEC-6 cells by quantitative reverse transcription (RT)-PCR. The administration of IL-4 and IL-13 resulted in a significant upregulation of ST3GalIV and HS3ST1 gene transcription, but had no effect on MUC2, in IEC-6 cells. RT-PCR studies also demonstrated the constitutive expression of IL-13Ralpha1 and IL-4R in IEC-6 cells. On the other hand, the ES product induced upregulation of ST3GalIV, but not HS3ST1 or MUC2, while coadministration of IL-13 and the ES product induced a slight but significant upregulation of MUC2. Co-incubation of live N. brasiliensis adult worms with IEC-6 cells resulted in the upregulation of ST3GalIV and MUC2. These results suggested that HS3ST1 gene expression is strictly regulated by IL-4/IL-13, while ST3GalIV and MUC2 gene expressions are regulated by redundant mechanisms.
Assuntos
Íleo/parasitologia , Interleucina-13/fisiologia , Interleucina-4/fisiologia , Mucina-2/biossíntese , Nippostrongylus/patogenicidade , Sialiltransferases/biossíntese , Sulfotransferases/biossíntese , Animais , Antígenos de Helmintos/fisiologia , Células Epiteliais/imunologia , Células Epiteliais/parasitologia , Perfilação da Expressão Gênica , Íleo/imunologia , Masculino , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , beta-Galactosídeo alfa-2,3-SialiltransferaseRESUMO
BACKGROUND: Larvae of several common species of parasitic nematodes obligately migrate through, and often damage, host lungs. The larvae induce strong pulmonary Type 2 immune responses, including T-helper (Th)2 cells as well as alternatively activated macrophages (AAMphi) and associated chitinase and Fizz/resistin family members (ChaFFs), which are thought to promote tissue repair processes. Given the prevalence of systemic or lung-resident Type 1-inducing pathogens in geographical areas in which nematodes are endemic, we wished to investigate the impact of concurrent Type 1 responses on the development of these Type 2 responses to nematode larval migration. We therefore infected BALB/c mice with the nematode Nippostrongylus brasiliensis, in the presence or absence of Plasmodium chabaudi chabaudi malaria parasites. Co-infected animals received both infections on the same day, and disease was assessed daily before immunological measurements were taken at 3, 5, 7 or 20 days post-infection. RESULTS: We observed that the nematodes themselves caused transient loss of body mass and red blood cell density, but co-infection then slightly ameliorated the severity of malarial anaemia. We also tracked the development of immune responses in the lung and thoracic lymph node. By the time of onset of the adaptive immune response around 7 days post-infection, malaria co-infection had reduced pulmonary expression of ChaFFs. Assessment of the T cell response demonstrated that the Th2 response to the nematode was also significantly impaired by malaria co-infection. CONCLUSION: P. c. chabaudi co-infection altered both local and lymph node Type 2 immune activation due to migration of N. brasiliensis larvae. Given recent work from other laboratories showing that N. brasiliensis-induced ChaFFs correlate to the extent of long-term lung damage, our results raise the possibility that co-infection with malaria might alter pulmonary repair processes following nematode migration. Further experimentation in the co-infection model developed here will reveal the longer-term consequences of the presence of both malaria and helminths in the lung.
Assuntos
Ativação Linfocitária/imunologia , Malária/imunologia , Nippostrongylus/imunologia , Plasmodium chabaudi/imunologia , Infecções por Strongylida/imunologia , Células Th1/metabolismo , Células Th2/metabolismo , Anemia , Animais , Feminino , Larva , Pulmão/imunologia , Pulmão/parasitologia , Pulmão/patologia , Malária/complicações , Malária/patologia , Malária/fisiopatologia , Camundongos , Camundongos Endogâmicos BALB C , Nippostrongylus/patogenicidade , Plasmodium chabaudi/patogenicidade , Infecções por Strongylida/complicações , Infecções por Strongylida/patologia , Infecções por Strongylida/fisiopatologia , Células Th1/imunologia , Células Th1/parasitologia , Células Th1/patologia , Células Th2/imunologia , Células Th2/parasitologia , Células Th2/patologia , CicatrizaçãoRESUMO
We have previously reported a significant decrease in serum PON1 activity after Nippostrongylus brasiliensis infection in Wistar rats in association with the inflammatory response mounted against the parasite in the migratory phase of infection. However, the roles of intestinal phase and the associated oxidative stress during N. brasiliensis infection on PON1 activity have not yet been elucidated. In the present study, we observed a significant reduction in serum paraoxonase and arylesterase activity on days 6 and 9 post-implantation with N. brasiliensis adult worms in the absence of a significant increase in various serum pro-inflammatory cytokines. In addition, provision of the antioxidant butylated hydroxyanisole (BHA) to adult worm-implanted rats did not ameliorate the reduction in PON1 activity. Due to the prolonged intestinal phase of gastrointestinal nematode infections, alterations in PON1 activity during this phase need to be further examined to elucidate the mechanism of alteration in PON1 activity.
Assuntos
Arildialquilfosfatase/sangue , Regulação para Baixo , Intestinos/parasitologia , Nippostrongylus/patogenicidade , Animais , Hidrolases de Éster Carboxílico/metabolismo , Citocinas/metabolismo , Inflamação , Enteropatias Parasitárias/parasitologia , Enteropatias Parasitárias/fisiopatologia , Masculino , Nippostrongylus/classificação , Contagem de Ovos de Parasitas , Ratos , Infecções por Strongylida/parasitologia , Infecções por Strongylida/fisiopatologiaRESUMO
Rheumatoid arthritis is an autoimmune disease that affects human beings worldwide. Infections have been associated to autoimmune diseases because their ability to induce a dominant cytokine response. Joint inflammation has been related to Th1 response because they induce high expression of proinflammatory cytokines TNF-alpha, IL-1, IFN-gamma. MRL/lpr mice spontaneously develop an autoimmune disease affecting joints, kidneys, etc. We compared incidence and severity of arthritis, antibody response, cytokine production, in mice infected with bacteria or helminthes in the Murphy Roths Large (MRL)lpr mice. Infections with helminthes Heligmosomoides polygyrus, Nippostrongylus brasiliensis or bacteria Nocardia brasiliensis and Staphylococcus aureus were studied. IL-4, IFN-gamma and IgG1, IgG2a antibody productions were determined. IFN-gamma was increased in all groups, the highest production was observed after bacterial infection; IL-4 production was higher after helminthes infection. IgG1 sera levels were increased in the helminthes infected group. IgG2a sera concentration was stimulated by bacterial infection. The histopathology showed that 100% of bacterial infected mice developed arthritis and severe tissue damage such as cartilage erosion and bone destruction. Animals infected with parasites showed a decreased incidence and severity of arthritis. Severity of tissue damage in joints is correlated with increased numbers of lymphocytes and macrophages immunoreactive to proinflammatory cytokines.
Assuntos
Artrite Experimental/fisiopatologia , Artrite Reumatoide/fisiopatologia , Nippostrongylus/imunologia , Infecções Estafilocócicas , Staphylococcus aureus/imunologia , Infecções por Strongylida , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Anti-Helmínticos/sangue , Artrite Experimental/imunologia , Artrite Reumatoide/imunologia , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Humanos , Camundongos , Camundongos Endogâmicos MRL lpr , Nippostrongylus/patogenicidade , Índice de Gravidade de Doença , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/fisiopatologia , Staphylococcus aureus/metabolismo , Staphylococcus aureus/patogenicidade , Infecções por Strongylida/imunologia , Infecções por Strongylida/fisiopatologia , Células Th1/imunologiaRESUMO
Acidic mucins such as sialomucin and sulfomucin produced by intestinal epithelial cells have been implicated in the protection of the mucosa from pathogens. In the present study, we analyzed the alteration of acidic mucins in the jejunum of euthymic and athymic rats infected with the nematode Nippostrongylus brasiliensis using alcian blue staining and a high iron-diamine method. The numbers of sialomucin+ goblet cells increased markedly 7 and 10 days post-infection and decreased gradually thereafter in euthymic rats, while athymic rats did not show sialomucin+ goblet cell hyperplasia at least until 28 days post-infection, suggesting that sialomucin production might be regulated by thymus-derived T cells. On the other hand, the numbers of sulfomucin+ goblet cells increased markedly 28 days post-infection in both euthymic and athymic rats despite the fact that sulfomucin+ goblet cell numbers in uninfected athymic rats were significantly smaller than in euthymic rats. Real-time polymerase chain reaction studies on the gene transcription levels of O-glycan sulfotransferases Gal3ST1, Gal3ST2, Gal3ST3, and Gal3ST4 in the jejunal epithelium increased gradually toward day 28 post-infection in euthymic and athymic rats. These results suggest that the production of sulfomucin and expression of Gal3STs are inducible by nematode infection without the activation of thymus-derived T cells.
Assuntos
Regulação da Expressão Gênica , Mucosa Intestinal , Mucinas/metabolismo , Nippostrongylus/patogenicidade , Sialiltransferases/metabolismo , Sulfotransferases/metabolismo , Animais , Células Caliciformes/metabolismo , Mucosa Intestinal/enzimologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/parasitologia , Jejuno/enzimologia , Jejuno/metabolismo , Jejuno/parasitologia , Masculino , Mucinas/genética , Ratos , Ratos Endogâmicos BN , Ratos Nus , Sialomucinas/metabolismo , Sialiltransferases/genética , Organismos Livres de Patógenos Específicos , Infecções por Strongylida/parasitologia , Infecções por Strongylida/fisiopatologia , Sulfotransferases/genética , Linfócitos T/imunologia , Timo/imunologiaRESUMO
Survival of parasitic helminths within a host requires immune evasion and excretory/secretory (ES) proteins may contribute to this process. Eosinophils are important effector cells in immunity of mice to the nematode Nippostrongylus brasiliensis and eosinophilic interleukin-5 transgenic (IL-5 Tg) mice are highly resistant to the earliest stages of primary infections. In contrast, Toxocara canis is largely resistant to eosinophils, with viable larvae encysted in tissues often surrounded by these and other leucocytes. The aim of this study was to investigate whether T. canis ES (TES) proteins inhibit eosinophil-dependent resistance to N. brasiliensis. Mouse serum pre-treated with TES had reduced capacity to mediate the adherence of leucocytes to N. brasiliensis infective-stage larvae (L3) and this correlated with reduced complement C3 deposition on the parasite. TES did not inhibit eosinophil survival or eotaxin-dependent eosinophil migration in vitro. Cellular inflammation and eosinophil degranulation in the skin in response to injection of L3 was also not impaired by TES. However, when TES was included with L3 in an inoculum given to IL-5 Tg mice, a greatly increased number of parasites migrated to the lung. This suggests that the early eosinophil-dependent resistance in these mice was suppressed, by mechanisms yet to be determined.
Assuntos
Eosinófilos/efeitos dos fármacos , Eosinófilos/imunologia , Proteínas de Helminto/toxicidade , Evasão da Resposta Imune , Nippostrongylus/imunologia , Nippostrongylus/patogenicidade , Toxocara canis/patogenicidade , Animais , Feminino , Pulmão/parasitologia , Pulmão/patologia , Masculino , Camundongos , Pele/parasitologia , Pele/patologiaRESUMO
BACKGROUND & AIMS: Visceral hypersensitivity, a hallmark of irritable bowel syndrome, is generally considered to be mechanosensitive in nature and mediated via spinal afferents. Both stress and inflammation are implicated in visceral hypersensitivity, but the underlying molecular mechanisms of visceral hypersensitivity are unknown. METHODS: Mice were infected with Nippostrongylus brasiliensis (Nb) larvae, exposed to environmental stress and the following separate studies performed 3-4 weeks later. Mesenteric afferent nerve activity was recorded in response to either ramp balloon distention (60 mm Hg), or to an intraluminal perfusion of hydrochloric acid (50 mmol/L), or to octreotide administration (2 micromol/L). Intraperitoneal injection of cholera toxin B-488 identified neurons projecting to the abdominal viscera. Fluorescent neurons in dorsal root and nodose ganglia were isolated using laser-capture microdissection. RNA was hybridized to Affymetrix Mouse whole genome arrays for analysis to evaluate the effects of stress and infection. RESULTS: In mice previously infected with Nb, there was no change in intestinal afferent mechanosensitivity, but there was an increase in chemosensitive responses to intraluminal hydrochloric acid when compared with control animals. Gene expression profiles in vagal but not spinal visceral sensory neurons were significantly altered in stressed Nb-infected mice. Decreased afferent responses to somatostatin receptor 2 stimulation correlated with lower expression of vagal somatostatin receptor 2 in stressed Nb-infected mice, confirming a link between molecular data and functional sequelae. CONCLUSIONS: Alterations in the intestinal brain-gut axis, in chemosensitivity but not mechanosensitivity, and through vagal rather than spinal pathways, are implicated in stress-induced postinflammatory visceral hypersensitivity.
Assuntos
Encéfalo/fisiologia , Intestinos/inervação , Mesentério/inervação , Nippostrongylus/patogenicidade , Infecções por Strongylida/metabolismo , Fibras Aferentes Viscerais/efeitos dos fármacos , Adjuvantes Imunológicos/farmacologia , Animais , Toxina da Cólera/farmacologia , Modelos Animais de Doenças , Feminino , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Gânglios Espinais/fisiopatologia , Expressão Gênica/efeitos dos fármacos , Ácido Clorídrico/farmacologia , Mucosa Intestinal/metabolismo , Mesentério/efeitos dos fármacos , Mesentério/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Gânglio Nodoso/efeitos dos fármacos , Gânglio Nodoso/metabolismo , Gânglio Nodoso/fisiopatologia , Octreotida/farmacologia , Reação em Cadeia da Polimerase , RNA/genética , Receptores de Somatostatina/biossíntese , Receptores de Somatostatina/genética , Infecções por Strongylida/parasitologia , Infecções por Strongylida/patologia , Nervo Vago/efeitos dos fármacos , Nervo Vago/metabolismo , Nervo Vago/fisiopatologia , Fibras Aferentes Viscerais/metabolismoRESUMO
Allergic asthma is responsible for widespread morbidity and mortality and its incidence has increased dramatically in industrialized countries over the past two decades. Here, we describe a new murine model of allergic asthma utilizing a novel allergen with intrinsic enzymatic activity similar to that reported for many environmental allergens. The allergen, NES, is excreted and secreted from the nematode Nippostrongylus brasiliensis, and can readily be isolated from in vitro parasite cultures. When NES is administered intranasally to presensitized mice, allergic airway disease develops, including airway hyper-responsiveness, airway eosinophilia, IgE antibody production and Th2 cytokine production. This disease is characteristic of atopic asthma and can be induced within 11 days, thus providing a platform for the rapid analysis of allergic disease and high throughput testing of immunomodulatory factors.