Influenza circulating strains in Argentina exhibit differential induction of cytotoxicity and caspase-3 in vitro

• Autores: Mersich, S E; Baumeister, Elsa; Riva, D.; Lewis, Adrian P.; Cadario, María Estela; Pontoriero, Andrea; Savy, V L
• Año de publicación: 2004
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: Journal of Clinical Virology 2004:31(2):134-139
• Materia: Gripe Aviar; Argentina; Virus de la Influenza A; Virus de la Influenza B
• Institución: Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos G. Malbrán"

Fil: Mersich, S.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Laboratorio de Virología. Departamento de Bioquímica; Argentina.
Fil: Baumeister, E.G. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Virología. Servicio de Virosis Respiratoria; Argentina.
Fil: Riva, D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Laboratorio de Virología. Departamento de Bioquímica; Argentina.
Fil: Lewis, A.P. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Virología. Servicio de Virosis Respiratoria; Argentina.
Fil: Cadario, M.E. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Virología. Servicio de Virosis Respiratoria; Argentina.
Fil: Pontoriero, A.V. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Virología. Servicio de Virosis Respiratoria; Argentina.
Fil: Savy, V.L. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Virología. Servicio de Virosis Respiratoria; Argentina.
Background: Human influenza infections are a significant cause of morbidity worldwide. Though damage to the respiratory epithelium and has been related to apoptosis, which occurs subsequent to influenza virus infection, little information is available regarding cell cytotoxicity of human strains. Objective: To study cytotoxicity performed in vitro by various circulating strains in Argentina. The study sample consisted of three vaccine strains (H1N1, H3N2, and B) administered during 1999–2000 in South America and three strains isolated from clinical samples, one, NAC (H1N1) obtained from an adult inpatient with human pneumonia; and the other two (T) and (T2) (H3N2) with influenza syndrome. Viral antigen was detected by an immunofluorescence test, conducted prior to viral isolation in MDCK cells. Strains were subtyped by the hemmaglutination inhibition test. Cytotoxic properties were determined by lactate dehydrogenase reaction (LDH), crystal violet staining and Hoechst staining. Caspase-3 activity, morphological changes of apoptosis, and viral yields were measured in MDCK infected cells. Results and conclusions: Cells infected by each of the strains exhibited apoptosis morphology by Hoechst staining and caspase-3 activity was high for both H1N1 strains. Further, high levels of LDH activity were detected for NAC and H3N2 strains tested, indicating the possible role of different viral proteins or functions on cell cytotoxicity. The NAC strain, isolated from human pneumonia and antigenically related to A/New Caledonia /20/99 (H1N1), was the highest cytotoxic strain and an excellent inducer of caspase-3 activity. In turn, no parameter was related to different viral yields. We conclude that human strains studied in this paper may be useful tools in the characterization of molecular determinants involved in viral cytopathogenicity.