RESUMO
Paracoccidioidomycosis (PCM) is a chronic systemic mycosis caused by the inhalation of the thermally dimorphic fungus Paracoccidioides brasiliensis as well as the recently described P. lutzii. Because the primary infection occurs in the lungs, we investigated the differential involvement of the right and left lungs in experimental P. brasiliensis infection. Lungs were collected from C57BL/6 mice at 70 days after intravenous infection with 1×106 yeast cells of a virulent strain of P. brasiliensis (Pb18). The left lung, which in mice is smaller and has fewer lobes than the right lung, yielded increased fungal recovery associated with a predominant interleukin-4 response and diminished synthesis of interferon-γ and nitric oxide compared with the right lung. Our data indicate differential involvement of the right and left lungs during experimental PCM. This knowledge emphasizes the need for an accurate, standardized protocol for tissue collection during studies of experimental P. brasiliensis infection, since experiments using the same lungs favor the collection of comparable data among different mice.
Assuntos
Pneumopatias Fúngicas/microbiologia , Pulmão/microbiologia , Paracoccidioides , Paracoccidioidomicose/microbiologia , Animais , Modelos Animais de Doenças , Interferon gama/análise , Interleucina-10/análise , Interleucina-4/análise , Masculino , Camundongos Endogâmicos C57BL , Óxido Nítrico/análise , Fatores de TempoRESUMO
Paracoccidioidomycosis (PCM) is a chronic systemic mycosis caused by the inhalation of the thermally dimorphic fungus Paracoccidioides brasiliensis as well as the recently described P. lutzii. Because the primary infection occurs in the lungs, we investigated the differential involvement of the right and left lungs in experimental P. brasiliensis infection. Lungs were collected from C57BL/6 mice at 70 days after intravenous infection with 1×106 yeast cells of a virulent strain of P. brasiliensis (Pb18). The left lung, which in mice is smaller and has fewer lobes than the right lung, yielded increased fungal recovery associated with a predominant interleukin-4 response and diminished synthesis of interferon-γ and nitric oxide compared with the right lung. Our data indicate differential involvement of the right and left lungs during experimental PCM. This knowledge emphasizes the need for an accurate, standardized protocol for tissue collection during studies of experimental P. brasiliensis infection, since experiments using the same lungs favor the collection of comparable data among different mice.
Assuntos
Animais , Masculino , Pneumopatias Fúngicas/microbiologia , Pulmão/microbiologia , Paracoccidioides , Paracoccidioidomicose/microbiologia , Modelos Animais de Doenças , Interferon gama/análise , /análise , /análise , Óxido Nítrico/análise , Fatores de TempoRESUMO
Paracoccidioidomycosis (PCM) is a chronic granulomatous disease caused by the thermally dimorphic fungus Paracoccidioides brasiliensis. T helper 1 (Th1)-mediated immunity is primarily responsible for acquired resistance during P. brasiliensis infection. On the contrary, the susceptibility is associated with occurrence of type-2 immunity (Th2), which is characterized by IL-4 release, B cell activation, and production of antibodies. Although antibodies are frequently associated with severe PCM, it is not clear whether they contribute to susceptibility or merely constitute a marker of infection stage. Here, we assessed the function of B cells during experimental P. brasiliensis infection in mice, and our results showed that B cell-knockout (B(KO)) mice are more susceptible than their wild-type littermate controls (C57BL/6, WT). The B(KO) mice showed higher mortality rate, increased number of colony-forming units in the lungs, and larger granulomas than WT mice. In the absence of B cells, we observed high levels of IL-10, whereas IFN-γ, TNF-α, and IL-4 levels were similar between both groups. Finally, we showed that transference of WT immune serum to B(KO) mice resulted in diminished infiltration of inflammatory cells and better organization of the pulmonary granulomas. Taken together, these data suggest that B cells are effectively involved in the control of P. brasiliensis growth and organization of the granulomatous lesions observed during the experimental PCM.
Assuntos
Linfócitos B/imunologia , Suscetibilidade a Doenças , Paracoccidioides/imunologia , Paracoccidioidomicose/imunologia , Animais , Contagem de Colônia Microbiana , Citocinas/metabolismo , Modelos Animais de Doenças , Granuloma/patologia , Pulmão/microbiologia , Pulmão/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Análise de SobrevidaRESUMO
INTRODUCTION: Periodontal disease is a chronic inflammation of the attachment structures of the teeth, triggered by potentially hazardous microorganisms and the consequent immune-inflammatory responses. In humans, the T helper type 17 (Th17) lineage, characterized by interleukin-17 (IL-17) production, develops under transforming growth factor-beta (TGF-beta), IL-1beta, and IL-6 signaling, while its pool is maintained by IL-23. Although this subset of cells has been implicated in various autoimmune, inflammatory, and bone-destructive conditions, the exact role of T lymphocytes in chronic periodontitis is still controversial. Therefore, in this study we investigated the presence of Th17 cells in human periodontal disease. METHODS: Gingival and alveolar bone samples from healthy patients and patients with chronic periodontitis were collected and used for the subsequent assays. The messenger RNA expression for the cytokines IL-17, TGF-beta, IL-1beta, IL-6, and IL-23 in gingiva or IL-17 and receptor activator for nuclear factor-kappaB ligand in alveolar bone was evaluated by real-time polymerase chain reaction. The production of IL-17, TGF-beta, IL-1beta, IL-6, and IL-23 proteins was evaluated by immunohistochemistry and the presence of Th17 cells in the inflamed gingiva was confirmed by immunofluorescence confocal microscopy for CD4 and IL-17 colocalization. RESULTS: Our data demonstrated elevated levels of IL-17, TGF-beta, IL-1beta, IL-6, and IL-23 messenger RNA and protein in diseased tissues as well as the presence of Th17 cells in gingiva from patients with periodontitis. Moreover, IL-17 and the bone resorption factor RANKL were abundantly expressed in the alveolar bone of diseased patients, in contrast to low detection in controls. CONCLUSION: These results provided strong evidence for the presence of Th17 cells in the sites of chronic inflammation in human periodontal disease.
Assuntos
Perda do Osso Alveolar/imunologia , Periodontite Crônica/imunologia , Interleucina-17/biossíntese , Linfócitos T Auxiliares-Indutores/imunologia , Adulto , Perda do Osso Alveolar/metabolismo , Estudos de Casos e Controles , Feminino , Imunofluorescência , Expressão Gênica , Humanos , Imuno-Histoquímica , Interleucina-1beta/biossíntese , Interleucina-23/biossíntese , Interleucina-6/biossíntese , Masculino , Microscopia Confocal , Ligante RANK/biossíntese , RNA Mensageiro/biossíntese , Linfócitos T Auxiliares-Indutores/metabolismo , Fator de Crescimento Transformador beta/biossínteseRESUMO
Food enteropathies involve uncontrolled or hypersensitivity reactions to ingested nutrients and may result in IgE and T-helper type 2 (Th2) responses as in food allergy. However, the precise role of B cells in the development of food enteropathies remains uncertain. In this work, we used B cell-deficient mice (B KO) and a model of peanut sensitization to examine the involvement of B lymphocytes in the pathogenesis of food allergy. Results showed that priming of wild-type (WT) mice with peanut proteins induced specific IgG1 and IgE responses in serum, with edema, tissue destruction, epithelial exulceration and inflammatory infiltrate in the gut of sensitized and challenged (S + Peanut) WT animals. In contrast, there was no sera immunoglobulin detection and absence of tissue destruction in the gut of B KO mice, which presented moderate inflammatory infiltrate and villous enlargement after peanut challenge. These animals presented marked decrease in IL-4 and TNF-alpha and high levels of IL-10, TGF-beta, IL-12p40 and IFN-gamma mRNA in the gut. Moreover, the expression of CCL5, CCL11 and CXCL1 was reduced in the gut of B KO mice, in contrast to elevated messages of CCL2 or similar detection of Th1-related chemokines in S + Peanut WT mice. Finally, we provided evidence that B cells are necessary to the development of food-related enteropathies and induction of gut inflammation during allergic reactions to food.
Assuntos
Linfócitos B/imunologia , Enterite/imunologia , Hipersensibilidade a Amendoim/imunologia , Alérgenos/imunologia , Animais , Arachis/imunologia , Quimiocinas/metabolismo , Citocinas/metabolismo , Enterite/patologia , Imunoglobulinas/biossíntese , Jejuno/imunologia , Jejuno/ultraestrutura , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Hipersensibilidade a Amendoim/patologia , Proteínas de Vegetais Comestíveis/imunologia , Células Th2/imunologiaRESUMO
Chagas disease (American trypanosomiasis) is caused by the protozoan parasite Trypanosoma cruzi. Chagas disease following solid-organ transplantation has occurred in Latin America. This report presents the occurrence of Chagas disease despite negative serological tests in both the donor and the recipient, as well as the effectiveness of treatment. A 21-year-old woman from the state of Sao Paulo (Brazil) underwent cadaveric donor liver transplantation in November 2005, due to cirrhosis of autoimmune etiology. Ten months after liver transplantation, she developed signs and symptoms of congestive heart failure (New York Heart Association functional class IV). The echocardiogram, which was normal preoperatively, showed dilated cardiac chambers, depressed left ventricular systolic function (ejection fraction = 35%) and moderate pulmonary hypertension. Clinical investigation discarded ischemic heart disease and autoimmune and other causes for heart failure. Immuno fluorescence (immunoglobulin M and immunoglobulin G) and hemagglutination tests for T cruzi were positive, and abundant T cruzi amastigotes were readily identified in myocardial biopsy specimens. Treatment with benznidazole for 2 months yielded an excellent clinical response. At the moment of submission, the patient remains in functional class I. This case highlighted that more appropriate screening for T cruzi infection is mandatory in potential donors and recipients of solid-organ transplants in regions where Chagas disease is prevalent. Moreover, it stressed that this diagnosis should always be considered in recipients who develop cardiac complications, since negative serological tests do not completely discard the possibility of disease transmission and since good results can be achieved with prompt trypanocidal therapy.
Assuntos
Cardiomiopatia Chagásica/diagnóstico , Transplante de Fígado/efeitos adversos , Complicações Pós-Operatórias/parasitologia , Trypanosoma cruzi/isolamento & purificação , Adulto , Animais , Cardiomiopatia Chagásica/tratamento farmacológico , Ecocardiografia , Evolução Fatal , Coração/parasitologia , Humanos , Masculino , Nitroimidazóis/uso terapêutico , Transplante de Pâncreas , Tripanossomicidas/uso terapêutico , Disfunção Ventricular EsquerdaRESUMO
AIM: To evaluate, by scanning electron microscopy (SEM), the presence of biofilms on the external surfaces of the apical third of roots of human primary teeth with vital or necrotic pulps with and without radiographically evident periradicular pathosis. METHODOLOGY: Eighteen teeth were selected: group I - normal pulp (n = 5), group II - pulp necrosis without radiographic evidence of periapical pathosis (n = 7) and group III - pulp necrosis with well-defined radiographic periapical pathosis (n = 6). After extraction, the teeth were washed with saline and immersed in 0.03 g mL(-1) trypsin solution for 20 min. The teeth were then washed in sodium cacodilate buffer and stored in receptacles containing modified Karnovsky solution. The teeth were sectioned, dehydrated in an ethanol series, critical-point dried with CO(2), sputter coated with gold and the external root surface in the apical third examined by SEM. RESULTS: In the teeth of groups I and II, the apical root surfaces were covered by collagen fibres, with no evidence of bacteria (100%). In the teeth of group III, the root apices had no collagen fibres but revealed resorptive areas containing microorganisms (cocci, bacilli, filaments and spirochetes) in all cases (100%). CONCLUSION: Microorganisms organized as biofilms on the external root surface (extraradicular infection) were detected in primary teeth with pulp necrosis and radiographically visible periapical pathosis.
Assuntos
Necrose da Polpa Dentária/microbiologia , Periodontite Periapical/microbiologia , Ápice Dentário/microbiologia , Dente Decíduo/microbiologia , Biofilmes , Polpa Dentária/ultraestrutura , Humanos , Microscopia Eletrônica de Varredura , Tecido Periapical/ultraestrutura , Ápice Dentário/ultraestruturaRESUMO
BACKGROUND: Hypersensitivity or uncontrolled responses against dietary antigens can lead to inflammatory disorders like food allergy and current models reflect a variety of causes but do not reveal the detailed modulation of gut immunity in response to food antigens after breakdown in mucosal tolerance. OBJECTIVE: To develop and characterize a murine model for food-induced intestinal inflammation and to demonstrate the modulation of gut immune response by dietary allergenic antigens. METHODS: C57BL/6 mice were sensitized with peanut proteins, challenged with peanut seeds and their sera and gut segments were collected for subsequent analyses. RESULTS: Sensitization and challenged with peanut seeds led to alterations in gut architecture with inflammatory response characterized by oedema in lamina propria and cell infiltrate composed mainly by eosinophils, mast cells, phagocytes, natural killer and plasma cells, together with low percentage of gammadelta+ and CD4+CD25+Foxp3+ cells in Peyer's patches. These animals also presented high levels of specific IgE and IgG1 in sera and modulation of mucosal immunity was mediated by increased expression of GATA-3, IL-4, IL-13 and TNF-alpha in contrast to low IFN-gamma in the gut. CONCLUSION: A murine model for food-induced intestinal inflammation was characterized in which modulation of gut immunity occurs by peanut antigens in consequence of T-helper type 2 (Th2) allergic response and failure of regulatory mechanisms necessary for mucosa homeostasis, resembling food allergy. This work shed some light on the understanding of the pathogenesis of gastrointestinal disorders and intolerance in the gut and supports the development of therapies for food-related enteropathies like food allergy, focusing on gut-specific immune response.
Assuntos
Colite/imunologia , Mucosa Intestinal/imunologia , Hipersensibilidade a Amendoim/complicações , Animais , Arachis/química , Arachis/imunologia , Colite/genética , Colite/patologia , Citocinas/metabolismo , Modelos Animais de Doenças , Fator de Transcrição GATA3/metabolismo , Expressão Gênica , Imunidade nas Mucosas , Imunoglobulina E/sangue , Imunoglobulina G/sangue , Imunoglobulinas/metabolismo , Mucosa Intestinal/patologia , Leucócitos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Nódulos Linfáticos Agregados/imunologia , Extratos Vegetais/química , Extratos Vegetais/imunologia , Células Th2/imunologia , Redução de PesoRESUMO
BACKGROUND AND PURPOSE: Sepsis is a systemic inflammatory response resulting from the inability of the host to restrict local infection. The failure of neutrophil migration to the infection site is one of the mechanisms involved in this process. Recently, it was demonstrated that this event is mediated by nitric oxide (NO). The present study addresses the possibility that peroxynitrite (ONOO(-)), a NO-derived powerful oxidizing and nitrating compound, could also be involved in neutrophil migration failure. EXPERIMENTAL APPROACH: Male C57Bl/6 mice were subjected to moderate (MSI) or severe (SSI) septic injury, both induced by cecal ligation and puncture (CLP). The leukocyte rolling and adhesion in the mesentery was evaluated by intravital microscopy. Cytokines (TNF-alpha and MIP-1alpha) were measured by ELISA and 3-nitrotyrosine (3-NT) by immunofluorescence. KEY RESULTS: Compared with saline pretreatment of SSI mice, pre-treatment with uric acid, a ONOO(-) scavenger, partially restored the failure of neutrophil rolling, adhesion and migration to the site of infection. These mice also presented low circulating bacterial counts and diminished systemic inflammatory response. Pretreatment with uric acid reduced 3-NT labelling in leukocytes in mesenteric tissues and in neutrophils obtained from peritoneal exudates. Finally, uric acid pretreatment enhanced significantly the survival rate in the SSI mice. Similarly, treatment with FeTPPs, a more specific ONOO(-) scavenger, re-established neutrophil migration and increased mice survival rate. CONCLUSIONS AND IMPLICATIONS: These results indicate that ONOO(-) contributed to the reduction of neutrophil/endothelium interaction and the consequent failure of neutrophil migration into infection foci and hence susceptibility to severe sepsis.
Assuntos
Infiltração de Neutrófilos/imunologia , Neutrófilos/imunologia , Ácido Peroxinitroso/metabolismo , Sepse/fisiopatologia , Animais , Antioxidantes/farmacologia , Ceco , Adesão Celular/imunologia , Movimento Celular/imunologia , Citocinas/metabolismo , Modelos Animais de Doenças , Ligadura , Masculino , Mesentério/fisiopatologia , Camundongos , Camundongos Endogâmicos C57BL , Neutrófilos/patologia , Punções , Índice de Gravidade de Doença , Taxa de Sobrevida , Ácido Úrico/farmacologiaRESUMO
OBJECTIVES: To evaluate the accuracy and reliability of conventional (Kodak Ektaspeed Plus film) and digitized radiographic images to detect the presence as well to estimate the size, as measured by an image analysis programme, of periapical radiolucencies induced in dog teeth in comparison with the histomorphometric data obtained from the same lesions by conventional and fluorescence microscopy. METHOD: After the removal of pulp, the root canals of five premolars from the same animal were left exposed for 7 days after which they were sealed for 60 days. At day 53, three more premolars were opened and left exposed to the oral cavity for 7 days. Intact premolars were used as control. Conventional radiographs were taken at day 0, day 7, day 30, day 45 and day 60. Morphometry in digitized radiographic images and histological sections were compared at day 7 and day 60 after setting the experimental series. RESULTS: Radiographically, periapical lesions were only detected 30 days after coronal sealing. A progressively increasing radiolucent lesion area was observed at day 45 and day 60. Histopathologically, 7 days after pulp removal dense inflammatory infiltrate and root resorption in the periapical region was observed. At day 7 and day 60, the lesion sizes were similar when evaluated by both conventional and fluorescence microscopy. Lesion size was about 20% larger in digitized radiographs in comparison with histological measurements. CONCLUSIONS: Although image digitization could not improve the detection of the early stages of periapical lesions, it provides a valuable quantitative assessment of extensive periapical lesions. In addition, fluorescence light microscopy enhances the visualization of the apical and periapical structures and seems to be a highly useful tool for histological evaluation, valuable for both qualitative and quantitative studies of periapical disease.