RESUMO
Microbial proteins have recently been found to have more benefits in clinical disease treatment because of their better-developed strategy and properties than traditional medicine. In this study, we investigated the effectiveness of a truncated peptide synthesized from the C-terminal sequence of pneumolysin, i.e., C70PLY4, in Streptococcus pneumoniae, in treating chronic inflammatory conditions. It has been shown that C70PLY4 significantly blocks the transendothelial migration of neutrophils and attenuates the formation of atherosclerotic plaque and the secretion of soluble forms of the intercellular adhesion molecule-1 (ICAM-1), the vascular cell adhesion molecule 1 (VCAM-1), and E-selectin in high-fat-diet/streptozotocin-induced inflammatory rats. The mechanism and the docking simulation analysis further indicated that C70PLY4 might serve as a Toll-like receptor 4 (TLR4) antagonist by competing for the binding site of MD2, an indispensable protein for lipopolysaccharide (LPS)-TLR4 interaction signaling, on the TLR4 structure. Moreover, compared to the full-length PLY, C70PLY4 seems to have no cytotoxicity in human vascular endothelial cells. Our study elucidated a possible therapeutic efficacy of C70PLY4 in reducing chronic inflammatory conditions and clarified the underlying mechanism. Thus, our findings identify a new drug candidate that, by blocking TLR4 activity, could be an effective treatment for patients with chronic inflammatory diseases.
Assuntos
Inflamação/tratamento farmacológico , Proteínas Mutantes/farmacologia , Proteínas Mutantes/uso terapêutico , Streptococcus pneumoniae/metabolismo , Estreptolisinas/farmacologia , Receptor 4 Toll-Like/antagonistas & inibidores , Sequência de Aminoácidos , Animais , Apoptose/efeitos dos fármacos , Proteínas de Bactérias/química , Proteínas de Bactérias/farmacologia , Sítios de Ligação , Caspase 3/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Dieta Hiperlipídica , Selectina E/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Molécula 1 de Adesão Intercelular/metabolismo , Lipopolissacarídeos , Camundongos , Simulação de Acoplamento Molecular , Proteínas Mutantes/química , NF-kappa B/metabolismo , Neutrófilos/citologia , Neutrófilos/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Solubilidade , Estreptolisinas/química , Estreptozocina , Receptor 4 Toll-Like/metabolismo , Migração Transendotelial e Transepitelial/efeitos dos fármacos , Molécula 1 de Adesão de Célula Vascular/metabolismoRESUMO
We have previously demonstrated that vaccination with a subunit dengue vaccine containing a consensus envelope domain III with aluminum phosphate elicits neutralizing antibodies against all four serotypes of dengue virus in mice. In this study, we evaluated the immunogenicity of the subunit dengue vaccine in non-human primates. After vaccination, monkeys that received the subunit vaccine with aluminum phosphate developed a significantly strong and long-lasting antibody response. A specific T cell response with cytokine production was also induced, and this correlated with the antibody response. Additionally, neutralizing antibodies against serotype 2 were detected in two of three monkeys. The increase in serotype-2-specific antibody titers and avidity observed in these two monkeys suggested that a serotype-2-biased antibody response occurs. These data provide evidence that a protective neutralizing antibody response was successfully elicited in non-human primates by the dengue subunit vaccine with aluminum phosphate adjuvant.
Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Vacinas contra Dengue/imunologia , Vírus da Dengue/imunologia , Proteínas do Envelope Viral/imunologia , Adjuvantes Imunológicos/administração & dosagem , Compostos de Alumínio/administração & dosagem , Animais , Afinidade de Anticorpos , Citocinas/metabolismo , Vacinas contra Dengue/administração & dosagem , Vacinas contra Dengue/genética , Vírus da Dengue/genética , Haplorrinos , Fosfatos/administração & dosagem , Linfócitos T/imunologia , Vacinas de Subunidades Antigênicas/administração & dosagem , Vacinas de Subunidades Antigênicas/genética , Vacinas de Subunidades Antigênicas/imunologia , Proteínas do Envelope Viral/genéticaRESUMO
The neutralization titer of a hemagglutinin (HA)-specific neutralizing antibody against new isolates reflect both the antigenic drift and the conformation status of HA protein in these new influenza viruses. Since most antigenic sites are in the HA1 domain of HA, using HA1 domain of influenza virus as antigen is of great importance in vaccine development. In this study, we investigate different purification processes for optimizing the immunological properties of an Escherichia coli-expressed HA1 domain (rH5HA1) of influenza H5N1 virus. rH5HA1 was expressed as inclusion bodies and extracted with 6M guanidine hydrochloride (GnHCl)/PBS buffer. The best condition for generating HA1-specific neutralization determinants is on-column oxidative refolding procedures with GSH/GSSG and l-arginine buffer. Others refolding procedures such as using high-pH buffer and/or different detergent solubilizations were found to be ineffective producing neutralization epitope recognized by a HA1-specific neutralizing monoclonal antibody that was raised against H5N1 virus.
Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Virus da Influenza A Subtipo H5N1/imunologia , Vacinas contra Influenza/imunologia , Sequência de Aminoácidos , Anticorpos Monoclonais/imunologia , Clonagem Molecular , Escherichia coli/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Humanos , Virus da Influenza A Subtipo H5N1/química , Virus da Influenza A Subtipo H5N1/genética , Vacinas contra Influenza/química , Vacinas contra Influenza/genética , Dados de Sequência Molecular , Testes de Neutralização , Dobramento de Proteína , Estrutura Terciária de ProteínaRESUMO
A novel dengue vaccine candidate comprised of a consensus dengue virus envelope protein domain III (cED III) was developed to fight against dengue virus infection. The amino acid sequence of this novel cED III was obtained by alignment of amino acid sequences from different isolates of the four serotypes of dengue viruses. A proof-of-concept study demonstrated that BALB/c mice immunized with the recombinant cED III developed neutralizing antibodies against all serotypes of dengue virus. Moreover, formulation of recombinant cED III with aluminum phosphate could induce long-lasting antibody responses and anamnestic neutralizing antibody responses following challenge with dengue virus at week 28 after priming. These results demonstrate the possibility of developing a single tetravalent vaccine against dengue viral infections.