RESUMO

The DC-SIGN glycoprotein is responsible for the initial adhesion of dengue virus (DENV) to immune cells by the carbohydrate recognition domain (CRD). There are thirteen soluble and membrane-bound DC-SIGN isoforms, but the role of soluble isoforms in the DENV internalization process is not known. Five isoforms with an altered or absent CRD were identified, and three different soluble isoforms were used to confirm the interactions with mannose residues. The results show the loss of binding ability of one soluble isoform and binding ability of two of them. All of them will be used to verify their role in the DENV internalization process.

Assuntos

Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Vírus da Dengue/metabolismo , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Manose/metabolismo , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Ligação Viral , Internalização do Vírus , Sequência de Aminoácidos , Sequência de Bases , Dengue/virologia , Vírus da Dengue/genética , Ligantes , Ligação Proteica/genética , Isoformas de Proteínas/genética

RESUMO

Human schistosomiasis is a neglected tropical disease of great importance in public health. A large number of people are infected with schistosomiasis, making vaccine development and effective diagnosis important control strategies. A rational epitope prediction workflow using Schistosoma mansoni hypothetical proteins was previously presented by our group, and an improvement to that approach is presented here. Briefly, immunodominant epitopes from parasite membrane proteins were predicted by reverse vaccinology strategy with additional in silico analysis. Furthermore, epitope recognition was evaluated using sera of individuals infected with S. mansoni. The epitope that stood out in both in silico and in vitro assays was used to compose a rational chimeric molecule to improve immune response activation. Out of 2185 transmembrane proteins, four epitopes with high binding affinities for human and mouse MHCII molecules were selected through computational screening. These epitopes were synthesized to evaluate their ability to induce TCD4+ lymphocyte proliferation in mice. Sm204830e and Sm043300e induced significant TCD4+ proliferation. Both epitopes were submitted to enzyme-linked immunosorbent assay to evaluate their recognition by IgG antibodies from the sera of infected individuals, and epitope Sm043300 was significantly recognized in most sera samples. Epitope Sm043300 also showed good affinity for human MHCII molecules in molecular docking, and its sequence is curiously highly conserved in four S. mansoni proteins, all of which are described as G-protein-coupled receptors. In addition, we have demonstrated the feasibility of incorporating this epitope, which showed low similarity to human sequences, into a chimeric molecule. The stability of the molecule was evaluated by molecular modeling aimed at future molecule production for use in diagnosis and vaccination trials.

Assuntos

Antígenos de Helmintos/imunologia , Epitopos Imunodominantes/imunologia , Schistosoma mansoni/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Anti-Helmínticos/sangue , Anticorpos Anti-Helmínticos/imunologia , Antígenos de Helmintos/genética , Linfócitos T CD4-Positivos/imunologia , Técnicas de Química Combinatória , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Feminino , Cadeias HLA-DRB1/imunologia , Proteínas de Helminto/química , Proteínas de Helminto/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Antígenos de Histocompatibilidade Classe II/metabolismo , Humanos , Epitopos Imunodominantes/genética , Epitopos Imunodominantes/metabolismo , Ativação Linfocitária , Proteínas de Membrana/química , Proteínas de Membrana/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Modelos Moleculares , Simulação de Acoplamento Molecular , Conformação Proteica , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/imunologia , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Schistosoma haematobium/imunologia , Schistosoma mansoni/genética , Esquistossomose mansoni/sangue , Esquistossomose mansoni/imunologia , Alinhamento de Sequência , Vacinas de Subunidades Antigênicas/imunologia , Vacinas Sintéticas/imunologia

RESUMO

BACKGROUND: The witches' broom disease is a plague caused by Moniliophthora perniciosa in the Theobroma cacao, which has been reducing the cocoa production since 1989. This issue motivated a genome project that has showing several new molecular targets, which can be developed inhibitors in order to control the plague. Among the molecular targets obtained, the UDP-N-acetylglucosamine pyrophosphorylase (UNAcP) is a key enzyme to construct the fungal cell wall. The inhibition of this enzyme results in the fungal cell death. RESULTS: The results show that the molecular recognition of the enzyme with the substrates occurs mainly by hydrogen bonds between ligands and Arg116, Arg383, Gly381, and Lys408 amino acids; and few hydrophobic interactions with Tyr382 and Lys123 residues. CONCLUSIONS: Among the compounds analyzed, the NAG5 showed the best binding energy (-95.2 kcal/mol). The next steps for the control of witches' broom plague involve the synthesis and biological evaluation of these compounds, which are in progress.