title: Dengue virus tetra-epitope peptide expressed in lettuce chloroplasts for potential use in dengue diagnosis.
abstract: Dengue virus causes about 100 million cases of dengue disease per year in the world. Laboratory diagnosis is done mainly by serological techniques, which in many cases use crude virus extracts that may cause cross-reactions to other flaviviruses. These undesirable cross-reactions can be reduced or eliminated by using recombinant proteins based on restricted epitopes. Aiming to decrease flaviviral cross-reactions and non-specific interactions in dengue serological assays, a plant expression system was chosen for recombinant antigen production as a reliable and inexpensive dengue diagnostic tool. In the present report, the lettuce plastid transformation system was applied to achieve efficient and stable tetra-epitope peptide antigen production, and its reactivity was evaluated. For this purpose, one putative epitope at positions 34 to 57 of E protein within the junction site of domains I and II of dengue virus (DENV) 1 to 4 serotypes linked by glycine linkers was expressed in lettuce chloroplasts. The potential immunoreactivity for the four DENV serotypes was evaluated using sera from patients of positive and negative dengue cases. Results indicated an overall sensitivity of 71.7% and specificity of 100%. No cross-reactions with the sera of yellow fever-positive or healthy individuals vaccinated against yellow fever were observed. This novel approach may provide an alternative system for the large-scale production of dengue recombinant antigens useful for serodiagnosis.
authors.affiliation: Departamento de Patologia Molecular, Universidade de Brasília, 70910-900 Brasília, Federal District, Brazil.
authors.forename: Franciele Roberta
authors.initials: FR
authors.lastname: Maldaner
authors.forename: Francisco José Lima
authors.initials: FJ
authors.lastname: Aragão
authors.forename: Flávia Barreto
authors.initials: FB
authors.lastname: dos Santos
authors.forename: Octavio Luiz
authors.initials: OL
authors.lastname: Franco
authors.forename: Monique
authors.initials: M
authors.lastname: da Rocha Queiroz Lima
authors.forename: Renato
authors.initials: R
authors.lastname: de Oliveira Resende
authors.forename: Raquel Medeiros
authors.initials: RM
authors.lastname: Vasques
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Nagata
mesh_terms: D000914:Antibodies, Viral / Q000097:blood*; D000956:Antigens, Viral / Q000235:genetics; D002736:Chloroplasts / Q000235:genetics; D003429:Cross Reactions; D003715:Dengue / Q000175:diagnosis*; D003716:Dengue Virus / Q000235:genetics / Q000276:immunology*; D000939:Epitopes / Q000235:genetics / Q000276:immunology*; D005822:Genetic Vectors; D006801:Humans; D018545:Lactuca / Q000235:genetics; D008969:Molecular Sequence Data; D030821:Plants, Genetically Modified; D012367:RNA, Viral / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D000939:Epitopes; D012367:RNA, Viral; D011994:Recombinant Proteins; D014759:Viral Envelope Proteins