RESUMO
BACKGROUND: There is still no effective method to prevent or treat severe acute respiratory syndrome (SARS), which is caused by SARS coronavirus (CoV). In the present study, we evaluated the efficacy of a fully human monoclonal antibody capable of neutralizing SARS-CoV in vitro in a Rhesus macaque model of SARS. METHODS: The antibody 5H10 was obtained by vaccination of KM mice bearing human immunoglobulin genes with Escherichia coli-producing recombinant peptide containing the dominant epitope of the viral spike protein found in convalescent serum samples from patients with SARS. RESULTS: 5H10, which recognized the same epitope that is also a cleavage site critical for the entry of SARS-CoV into host cells, inhibited propagation of the virus and pathological changes found in Rhesus macaques infected with the virus through the nasal route. In addition, we analyzed the mode of action of 5H10, and the results suggested that 5H10 inhibited fusion between the virus envelope and host cell membrane. 5H10 has potential for use in prevention and treatment of SARS if it reemerges. CONCLUSIONS: This study represents a platform to produce fully human antibodies against emerging infectious diseases in a timely and safe manner.
Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Glicoproteínas de Membrana/imunologia , Síndrome Respiratória Aguda Grave/terapia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/imunologia , Proteínas do Envelope Viral/imunologia , Enzima de Conversão de Angiotensina 2 , Animais , Animais Geneticamente Modificados , Anticorpos Monoclonais/metabolismo , Anticorpos Neutralizantes/metabolismo , Anticorpos Antivirais/metabolismo , Western Blotting , Domínio Catalítico , Fusão Celular , Modelos Animais de Doenças , Células Gigantes/efeitos dos fármacos , Humanos , Imuno-Histoquímica , Pulmão/patologia , Pulmão/virologia , Macaca mulatta , Glicoproteínas de Membrana/genética , Camundongos , Peptidil Dipeptidase A , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/farmacologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Síndrome Respiratória Aguda Grave/imunologia , Síndrome Respiratória Aguda Grave/virologia , Glicoproteína da Espícula de Coronavírus , Proteínas do Envelope Viral/genéticaRESUMO
IL-33 plays an important role in inflammatory diseases including hypersensitive diseases like asthma, autoimmune diseases like rheumatoid arthritis, cardiovascular diseases like heart failure and neurodegenerative diseases like Alzheimer's disease. Here we reported the generation of an IL-33 transgenic mouse, in which mouse IL-33 full-length cDNA was controlled under the CMV promoter. The transgenic IL-33 was released as a cleaved form with molecular weight of 18kDa in pulmonary, nephritic, cardiac and pancreatic tissues in transgenic mice and the pI of 18kDa peptide was about pH 3-5 on the 2D PAGE which was similar with the activated peptide of IL-33. Histological analysis showed massive airway inflammation with infiltration of eosinophils around bronchi and small blood vessels, hyperplasia of goblet cells and accumulation of mucus-like material in pulmonary tissue of transgenic mice. An increase of IL-5, IL-8, IL-13 and IgE was detected in bronchoalveolar lavage fluid (BALF) of transgenic mice, which are inflammatory factors. These findings suggest transgenic IL-33 could be cleaved and secreted in an activated form and play an important role in the pathogenesis of pulmonary inflammation.
Assuntos
Citocinas/metabolismo , Interleucinas/imunologia , Pneumonia/genética , Pneumonia/imunologia , Animais , Líquido da Lavagem Broncoalveolar/química , Movimento Celular/genética , Citocinas/genética , Eosinófilos/patologia , Células Caliciformes/patologia , Hiperplasia , Mediadores da Inflamação/metabolismo , Interleucina-33 , Interleucinas/genética , Interleucinas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Depuração Mucociliar/genética , Depuração Mucociliar/imunologia , Pneumonia/metabolismo , Pneumonia/fisiopatologia , Transgenes/genética , Transgenes/imunologiaRESUMO
OBJECTIVE: To establish the transgenic mouse of cTnT(R141W) gene to make an animal model of dilated cardiomyopathy. METHODS: A transgenic plasmid was constructed by inserting the cTnT(R141W) gene driven by the alpha-MHC promoter. The expression level of the gene was determined with Northern blotting. Pathologic changes were observed by light microscopy and transmission electronic microscopy and analyzed with echocardiography. The localization of the mutant human cTnT protein was detected by immunohistochemistry. The hypertrophy markers were analyzed by RT-PCR. RESULTS: Transgenic mice carrying the cTnT(R141W) mutation were established. The cTnT(R141W) was expressed by 1.5- to 2.0-fold that of the endogenous cTnT gene and was showed to assemble in the sarcomere. The transgenic heart exhibited a thinner ventricular wall and an enlarged ventricular chamber. Interstitial fibrosis and the elongated and lysed myofrils were also observed in the transgenic heart tissue. The function on EF%, FS% and movement of the ventricular wall was significantly decreased. The immature death occurred after 4 months of age and the immature death rate was 11.1% before 8 months of age in the cTnT(R141W) mice. The increased NPPB, ACTA1 and decreased ATP2A2 were detected in the transgenic heart. CONCLUSIONS: The expression of mutant cTnT(R141W) in the mouse heart caused ventricular chamber enlargement, systolic dysfunction, myocardial hypertrophy, and interstitial fibrosis, suggesting that the cTnT(R141W) gene is a causal factor for DCM and that the cTnT(R141W) transgenic mouse is a useful animal model for the study of human DCM.