title: Diagnostic tool based on an HTLV-1-Tax expression system in eukaryotic cells using a poxvirus vector.
abstract: Human T-lymphotropic virus 1 (HTLV-1) induces an immune-mediated inflammatory disease affecting the nervous system that eventually is accompanied by ocular, rheumatic and dermatologic manifestations (HTLV-1 associated myelopathy/tropical spastic paraparesis, or HAM/TSP). Proviral load and HTLV-1 protein expression, mainly of Tax, is correlated with disease progression and induction of host-virus equilibrium breakdown that, reportedly, involves the presence of Tax-specific cytotoxic T lymphocytes (CTL), T regulatory cells and anti-Tax antibodies. Based on knowledge of anti-Tax antibodies as markers of disease progression, the objectives of this study were both to design an infection/transfection system using the Vaccinia virus and a tax-encoding plasmid for the expression of Tax protein as well as to use this cell support to evaluate anti-Tax IgG by flow cytometry. The flow cytometry assay was standardized using pooled sera from each test group (negative, asymptomatic and HAM/TSP patients). The HAM/TSP group presented higher IgG anti-Tax reactivity (above 70%) than the asymptomatic group (nearly 40% reactivity). The data indicate that the infection/transfection system is useful for assessing Tax expression. This is a promising assay for use as a diagnostic tool to detect IgG anti-Tax and monitor HTLV-1 infected individuals.
authors.affiliation: Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais - UFMG, Belo Horizonte, Brazil.
authors.forename: Jaqueline Gontijo
authors.initials: JG
authors.lastname: de Souza
authors.forename: Flávio Guimarães da
authors.initials: FG
authors.lastname: Fonseca
authors.forename: Olindo Assis
authors.initials: OA
authors.lastname: Martins-Filho
authors.forename: Andrea
authors.initials: A
authors.lastname: Teixeira-Carvalho
authors.forename: Camila Pacheco Silveira
authors.initials: CP
authors.lastname: Martins
authors.forename: Luciana Debortoli
authors.initials: LD
authors.lastname: Carvalho
authors.forename: Jordana Grazziela Alves
authors.initials: JG
authors.lastname: Coelho-Dos-Reis
authors.forename: Edel Figueiredo
authors.initials: EF
authors.lastname: Barbosa-Stancioli
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D000956:Antigens, Viral / Q000235:genetics / Q000302:isolation & purification; D002522:Chlorocebus aethiops; D005434:Flow Cytometry / Q000379:methods* / Q000592:standards; D016356:Gene Products, tax / Q000235:genetics / Q000302:isolation & purification; D005822:Genetic Vectors; D015490:HTLV-I Infections / Q000175:diagnosis* / Q000276:immunology; D006801:Humans; D010957:Plasmids; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification; D014616:Vaccinia virus / Q000235:genetics; D014709:Vero Cells; D014773:Virology / Q000379:methods* / Q000592:standards
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D016356:Gene Products, tax; D011994:Recombinant Proteins; C514970:tax protein, Human T-lymphotrophic virus 1