RESUMO
Digestive and cardiodigestive forms of Chagas' disease are observed in 2% to 27% of the patients, depending on their geographic location, Trypanosoma cruzi strain and immunopathological responses. The aim of this work was to evaluate the role of NOD2 innate immune receptor in the pathogenesis of the digestive system in Chagas' disease. Patients with digestive form of the disease showed lower mRNA expression of NOD2, higher expression of RIP2 and α-defensin 6, compared to indeterminate form, detected by Real-time PCR in peripheral blood mononuclear cells. In addition, there was a negative correlation between the expression of NOD2 and the degree of dilation of the esophagus, sigmoid and rectum in those patients. The infection of NOD2-/- mice with T. cruzi strain isolated from the digestive patient induced a decrease in intestinal motility. Histopathological analysis of the colon and jejunum of NOD2-/- and wild type C57BL/6 animals revealed discrete inflammatory foci during the acute phase of infection. Interestingly, during the chronic phase of the infection there was inflammation and hypertrophy of the longitudinal and circular muscular layer more pronounced in the colon and jejunum from NOD2-/- animals, when compared to wild type C57BL/6 mice. Together, our results suggest that NOD2 plays a protective role against the development of digestive form of Chagas' disease.
Assuntos
Doença de Chagas/imunologia , Proteína Adaptadora de Sinalização NOD2/genética , Proteína Adaptadora de Sinalização NOD2/imunologia , Proteína Adaptadora de Sinalização NOD2/metabolismo , Trypanosoma cruzi/imunologia , Adolescente , Adulto , Idoso , Animais , Brasil , Doença de Chagas/patologia , Colo/microbiologia , Colo/patologia , Modelos Animais de Doenças , Feminino , Humanos , Imunidade Inata , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/genética , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/metabolismo , Adulto Jovem , alfa-Defensinas/genética , alfa-Defensinas/metabolismoRESUMO
Paneth cells (PCs) are specialized epithelial cells of the small bowel that contain multiple secretory granules filled with antimicrobial peptides and trophic factors, which are essential for the control of the microorganisms growth and maintaining intestinal integrity. Alterations in their function are associated with an imbalance of the normal microbiota, gastrointestinal infections and inflammatory processes, such as Crohn's disease (CD). One of the most common murine models for studying CD is IL-10-/- mouse. IL-10-/- mice when housed in conventional conditions and take contact with commensal microorganisms develop an acute enterocolitis mediated by a Th1 immune response. Even though, alterations in PCs function are related to CD, they had not been characterized yet in this mouse model. Here we show that in specific pathogen free conditions IL-10-/- mice have aberrant granules and a large number of immature PCs at the bottom of the crypt in the ileum of IL-10-/- mice before developing intestinal inflammation, along with a reduced expression of Indian Hedgehog. In addition, IL-10-/- Paneth cells presented a reduced expression of cryptidin-4, and a heterogeneous distribution of lysozyme+ granules. The alterations in the maturation of the PCs at the bottom of the crypt were not modified after the colonization by the conventional microbiota. On the other hand, depletion of microbiota altered the phenotype, but did not normalize PCs. Our results suggest that IL-10 could be necessary for the integrity of PCs. Moreover, our results help to explain why IL-10-/- mice develop enterocolitis in response to microorganisms.
Assuntos
Interleucina-10/genética , Celulas de Paneth/citologia , Vesículas Secretórias/metabolismo , alfa-Defensinas/genética , Animais , Diferenciação Celular , Células Cultivadas , Modelos Animais de Doenças , Técnicas de Silenciamento de Genes , Proteínas Hedgehog/metabolismo , Masculino , Camundongos , Microbiota , Celulas de Paneth/imunologia , Celulas de Paneth/metabolismo , Fenótipo , Organismos Livres de Patógenos Específicos , Células Th1/imunologiaRESUMO
Lettuce (Lactuca sativa L.) is an annual plant of the daisy family, Asteraceae, with high food and medicinal value. However, the crop is susceptible to several viruses that are transmitted by aphids and is highly vulnerable to post-harvest diseases, as well as insect and mammal pests and fungal and bacterial diseases. Here, the rabbit defensin gene NP-1 was transferred into lettuce by Agrobacterium-mediated transformation to obtain a broad-spectrum disease-resistant lettuce. Transgenic lettuce plants were selected and regenerated on selective media. The presence of the NP-1 gene in these plants was confirmed by western blot analyses. Resistance tests revealed native defensin NP-1 expression conferred partial resistance to Bacillus subtilis and Pseudomonas aeruginosa, which suggests new possibilities for lettuce disease resistance.
Assuntos
Expressão Gênica , Lactuca/genética , Plantas Geneticamente Modificadas , alfa-Defensinas/genética , Animais , Técnicas de Transferência de Genes , CoelhosRESUMO
BACKGROUND/AIMS: The innate immune response is remarkably important for controlling infections. Information about the participation of antimicrobial peptides (AMPs) in response to dengue virus (DENV) is scarce. The aim of this study was to examine the AMP response to DENV-2 in human THP-1 cells and neutrophils. METHODS: Protein and mRNA levels of two AMPs - hBD-1 and cathelicidin LL-37 - were assessed in DENV-infected macrophage-like THP-1 cells using qRT-PCR and indirect immunofluorescence. Also, mRNA levels of α-defensins (hDEFAs) and LL-37 were examined by qRT-PCR in human neutrophils taken from peripheral blood and treated with DENV-2. RESULTS: mRNA expression of hBD-1 rose in THP-1 cells at 24-72 h, while protein expression increased later, from 48 to 72 h after infection. Cathelicidin LL-37 mRNA expression of DENV-infected THP-1 cells was observed at 6-48 h after infection, while protein levels increased importantly up to 72 h after infection. Regarding neutrophils, the mRNA expression of hDEFAs and LL-37 increased slightly at 2 and 5 h after the contact with DENV-2. CONCLUSION: THP-1 cells and human neutrophils strongly respond to DENV by producing AMPs: hBD-1 and LL-37 for the THP-1 cells and hDEFAs and LL-37 for neutrophils. However, the direct effect of these molecules on DENV particles remains unclear.
Assuntos
Peptídeos Catiônicos Antimicrobianos/genética , Vírus da Dengue/fisiologia , Monócitos/imunologia , Neutrófilos/imunologia , Peptídeos Catiônicos Antimicrobianos/análise , Linhagem Celular , Células Cultivadas , Vírus da Dengue/imunologia , Humanos , Monócitos/metabolismo , Monócitos/virologia , Neutrófilos/metabolismo , Neutrófilos/virologia , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , alfa-Defensinas/análise , alfa-Defensinas/genética , beta-Defensinas/análise , beta-Defensinas/genética , CatelicidinasRESUMO
Defensins confer host defense against microorganisms and are important for human health. Single nucleotide polymorphisms (SNPs) in defensin gene-coding regions could lead to less active variants. Using SNP data available at the dbSNP database and frequency information from the 1000 Genomes Project, two DEFA5 (L26I and R13H) and eight DEFB1 (C35S, K31T, K33R, R29G, V06I, C12Y, Y28* and C05*) missense and nonsense SNPs that are located within mature regions of the coded defensins were retrieved. Such SNPs are rare and population restricted. In order to assess their antibacterial activity against Escherichia coli, two linear regression models were used from a previous work, which models the antibacterial activity as a function of solvation potential energy, using molecular dynamics data. Regarding only the antibacterial predictions, for HD5, no biological differences between wild-type and its variants were observed; while for HBD1, the results suggest that the R29G, K31T, Y28* and C05* variants could be less active than the wild-type one. The data here reported could lead to a substantial improvement in knowledge about the impact of missense SNPs in human defensins and their world distribution. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 633-644, 2016.
Assuntos
Antibacterianos , Escherichia coli/efeitos dos fármacos , Simulação de Dinâmica Molecular , Polimorfismo de Nucleotídeo Único , alfa-Defensinas , beta-Defensinas , Antibacterianos/química , Antibacterianos/farmacologia , Humanos , alfa-Defensinas/química , alfa-Defensinas/genética , alfa-Defensinas/farmacologia , beta-Defensinas/química , beta-Defensinas/genética , beta-Defensinas/farmacologiaRESUMO
Antimicrobial peptide innate immunity plays a central role in the susceptibility to infectious diseases, as has been described extensively in different settings. However, the role that these molecules play in the immunity mediated by polymorphonuclear phagocytes as part of the innate immunity of ageing individuals has not been described. In the present study, we addressed the question whether antimicrobial activity in polymorphonuclear cells from elderly individuals was altered in comparison with young adults. We compared phagocytosis index, bacterial killing efficiency, myeloperoxidase activity and cathelicidin expression. Results showed that there were no statistical differences among groups. However, human neutrophil peptide-1 (HNP-1) was decreased in the elderly individuals group. Results suggest that the decreased HNP-1 production in the polymorphonuclear phagocytes form elderly individuals might have an important participation in the increased susceptibility to infectious diseases.
Assuntos
Envelhecimento/metabolismo , Neutrófilos/imunologia , Neutrófilos/metabolismo , alfa-Defensinas/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/genética , Feminino , Expressão Gênica , Humanos , Imunidade Inata , Interleucina-1/genética , Interleucina-1/metabolismo , Espaço Intracelular , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Masculino , Peroxidase/genética , Peroxidase/metabolismo , Fagocitose , alfa-Defensinas/genéticaRESUMO
Human neutrophil peptide-1 (HNP-1) is an important defense molecule in neutrophils and Sertoli cells and plays an important role in the blood-testis barrier. In this study, we investigated the behavior of Sertoli cells transfected with the HNP-1 gene and compared the ability of Sertoli cells and fibroblast cells to resist transfection. Total RNA was isolated from human blood. The DNA coding sequence of HNP-1 was amplified by reverse transcription-polymerase chain reaction (RT-PCR) and the eukaryotic expression vector pEGFP-N3-HNP-1 was identified by PCR, endonuclease digestion, and sequencing. Bovine Sertoli cells and fibroblast cells were transfected with pEGFP-N3-HNP-1 using Liposome reagent. The transfection efficiency and the behavior of the transfected cells were evaluated at 24, 48 and 72 h as well as at other times after transfection. The plasmid pEGFP-N3-HNP-1 was successfully constructed. The cells achieved maximum transfection efficiency at 48 h. Two weeks after transfection, the cells began to stop dividing. The ability of Sertoli cells to resist transfection was higher compared to fibroblast cells. The ability of the 2 cell types to resist transfection was higher with plasmid pEGFP-N3-HNP-1 than with the plasmid pEGFP-N3. The injury to Sertoli cells caused by transfection with the HNP-1 gene was less pronounced than in fibroblast cells, which may be closely correlated with the physiological function of Sertoli cells.
Assuntos
Fibroblastos/metabolismo , Vetores Genéticos/química , Plasmídeos/química , Proteínas Recombinantes de Fusão/genética , Células de Sertoli/metabolismo , alfa-Defensinas/metabolismo , Animais , Barreira Hematotesticular , Bovinos , Fibroblastos/citologia , Expressão Gênica , Vetores Genéticos/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Masculino , Especificidade de Órgãos , Plasmídeos/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Células de Sertoli/citologia , Transfecção , Transgenes , alfa-Defensinas/genéticaRESUMO
Acute pancreatitis is a life-threatening situation, frequently associated with uncontrolled local and systemic inflammation, and aging is associated with a worst prognosis. Antimicrobial peptides are ancient molecules that belong to innate immunity, produced by epithelial and immune cells, and are able to trigger a myriad of effector responses. We have hypothesized that antimicrobial peptides could play an important role during serious pancreatic injury. To investigate our hypothesis, α-defensin-5, α-defensin-7 and CRAMP gene expression levels were measured in the intestinal tissue of old and young rats submitted to chemical pancreatic damage. We found significantly higher levels of α-defensin-5 and α-defensin-7, but not CRAMP, in the samples from old mice. This increase was not associated with a worse systemic inflammatory response. We conclude that α-defensins may have a pivotal role during acute pancreatitis and that the elderly develops a more severe local, but not systemic inflammatory process.
Assuntos
Envelhecimento/imunologia , Intestinos/imunologia , Pancreatite/imunologia , alfa-Defensinas/biossíntese , Envelhecimento/genética , Envelhecimento/metabolismo , Animais , Peptídeos Catiônicos Antimicrobianos , Catelicidinas/genética , Catelicidinas/metabolismo , Expressão Gênica , Imunidade Inata , Mucosa Intestinal/metabolismo , Masculino , Camundongos , Pancreatite/genética , Pancreatite/metabolismo , Ratos , Ratos Wistar , Fator de Necrose Tumoral alfa/sangue , Fator de Necrose Tumoral alfa/genética , alfa-Defensinas/sangue , alfa-Defensinas/genéticaRESUMO
Tuberculosis (TB) is one of the most important infectious diseases, causing 1.8 million deaths annually worldwide. This problem has increased because of the association with human immmunodeficiency virus and diabetes mellitus type 2, mainly in developing countries. In the past few years it has been highlighted the significance of antimicrobial peptides in the immunopathogenesis of TB ex vivo and in experimental models studies. In this study we analyzed the expression of CAMP, DEFA1, DEFB4, and DEFB103A in patients with latent TB and progressive TB with and without comorbidity with diabetes mellitus type 2. Antimicrobial peptide gene expression increased during progressive TB, which could be used as a biomarker for reactivation. By contrast, patients with diabetes mellitus type 2 have lower antimicrobial peptides gene expression, suggesting that the lack of its proper production in these patients contribute to enhance the risk for TB reactivation.