DETERMINAÇÃO E MODELAGEM DE EPÍTOPOS B ESPECÍFICOS PARA DENGUE 1 E DENGUE 2
Abstract (Summary)The development of serologic reagents and assays for serotype specific diagnosis of dengue virus infections has two main goals: 1) as a clinical tool for prediction and prevention of severe complication of dengue infections; 2) as an epidemiological importance for identification of dengue virus circulating or invading a given area. In the present study, computation of methods were used to predict physico-chemical characteristics of amino acid sequences present in the E (envelope) protein of DENV-1 and DENV-2 which would represent potential B epitopes peptides. Predictive algorithms used hidrofilicity, flexibility of the main chain of aminoacids, and of the time of retention in High Performance Liquid Chromatography - HPLC are accessible in the Word Wide Web (Internet) as well as Genbank information on the nucleotide and amino acid sequences of dengue E protein performed in various areas of the world. Other computational assays were used to propose the tri-dimensional structure and location of the peptides, through molecular modeling of the dengue virus E protein, the main responsible for induction of humoral immune responses. Seven peptides corresponding to linear structures of the E protein were identified as potential B epitopes, three from DENV-1 and 4 from DENV-2 viruses. Six of these peptides were synthesized and used to immunize Balb/C mice. The humoral response of the human sera were analyzed by ELISA tests using the corresponding peptide as antigen, either pure different from the carrier protein used in the immunization procedures (KLH). Preliminary results indicate immunogenic properties of the peptides, in particular peptides number 3 of DENV-1 and number 3 of DENV-2. Polyclonal antibodies from sera of mice immunized with peptides 3 of DENV-1 and 3 of DENV-2 do not show cross-reactions. The analysis of serotype specificity of the induced antibodies is been studied by the preparation of hybridomas and production of monoclonal antibodies from the immunized Balb/C mice.
Advisor:Luiz Hildebrando Pereira da Silva
Source Type:Master's Thesis
Date of Publication:12/01/2005