title: Polyclonal antibodies against properly folded Dengue virus NS1 protein expressed in E. coli enable sensitive and early dengue diagnosis.
abstract: The non-structural 1 (NS1) protein plays an important role in dengue diagnosis because it has been detected as a soluble serum antigen in both primary and secondary infections. The NS1 protein was expressed in Escherichia coli cells, and the efficiency of four different refolding protocols was tested. All of the protocols generated dimeric NS1 in a conformation similar to that of the protein expressed by eukaryotic cells. A polyclonal antibody produced from the properly folded E. coli recombinant NS1 (rNS1) protein proved to be a useful tool for the diagnosis of Dengue virus because it detected 100% of the Dengue virus 2 (DENV2) in infected patients' sera and 60% of the DENV IgM-positive sera not detected by commercial NS1-based diagnostic kits. These data suggest a high-efficiency method for correctly folding rNS1 that maintains its structural and immunogenic properties. In addition, a detection method using the polyclonal antibody against correctly folded rNS1 seemed to be more sensitive and efficient for NS1 detection in serum, highlighting its usefulness for developing a high-sensitivity diagnostic kit.
authors.affiliation: Laboratório de Genômica Estrutural, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-590, Brazil.
authors.forename: Diego
authors.initials: D
authors.lastname: Allonso
authors.forename: Marcela
authors.initials: M
authors.lastname: da Silva Rosa
authors.forename: Diego Rodrigues
authors.initials: DR
authors.lastname: Coelho
authors.forename: Simone Morais
authors.initials: SM
authors.lastname: da Costa
authors.forename: Rita Maria Ribeiro
authors.initials: RM
authors.lastname: Nogueira
authors.forename: Fernando Augusto
authors.initials: FA
authors.lastname: Bozza
authors.forename: Flavia Barreto Dos
authors.initials: FB
authors.lastname: Santos
authors.forename: Ada Maria
authors.initials: AM
authors.lastname: de Barcelos Alves
authors.forename: Ronaldo
authors.initials: R
authors.lastname: Mohana-Borges
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology*; D015153:Blotting, Western; D003715:Dengue / Q000175:diagnosis*; D003716:Dengue Virus / Q000235:genetics / Q000276:immunology*; D042241:Early Diagnosis; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D006023:Glycoproteins / Q000276:immunology; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D017510:Protein Folding; D011817:Rabbits; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism
chemical_list: D000914:Antibodies, Viral; D006023:Glycoproteins; C082515:NS1 protein, dengue-1 virus; D017361:Viral Nonstructural Proteins