RESUMO
UNLABELLED: Various methods of handling samples of avian influenza prior to detecting influenza viruses can significantly influence both, the detection of the virus and the quantification of viral nucleic acids. The quantity of influenza viral RNA remaining in different collecting buffers and kept at temperatures of -20°C, +4°C or +22°C for various lengths of time, was determined. The quantity of viral RNA remained the same for 120 days at -20°C, but decreased when the samples were stored at either +4°C or +22°C. The quantity of RNA was influenced by the composition of the collecting buffer. The influenza virus sample that is to be used for RNA quantification can be stored at +4°C and freeze and thaw cycles should be avoided during transport. Our results clearly indicate that the quality and quantity of influenza virus nucleic acid depends on the chemical composition of used buffer and also that the samples can be protected from degradation even if they are not stored at ultra-low temperatures. However, repeated thaw and freeze cycles will damage viral RNA even if kept in stabilizing buffers. KEYWORDS: influenza virus; degradation; RNA; buffer.
Assuntos
Influenza Aviária , RNA Viral , Animais , Influenza Aviária/virologia , Orthomyxoviridae/genética , RNA Viral/genética , Manejo de Espécimes , Temperatura , Fatores de TempoRESUMO
Intratracheal immunization of mice with inactivated influenza B virus and delipidated Bacillus firmus as adjuvant increases protection of mice against infection with the homologous virus strain and induces cross-protection: mice immunized by influenza virus B/Yamanashi 166/98 were protected even against phylogenetically distant virus drift variant B/Lee/40 lethal for mice.
Assuntos
Adjuvantes Imunológicos/administração & dosagem , Imunização/métodos , Vírus da Influenza B/imunologia , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/imunologia , Administração por Inalação , Animais , Bacillus/imunologia , Proteção Cruzada , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Análise de Sobrevida , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Produtos Inativados/imunologiaRESUMO
Intranasal immunization of guinea pigs with inactivated type B influenza virus plus inactivated Bacillus firmus as an adjuvant compared to the virus alone yields higher titers of serum hemagglutination-inhibiting antibodies and virus-neutralizing antibodies. This phenomenon could be useful in standard serology, especially in the preparation of immune sera against highly pathogenic strains for in vitro diagnosis.
Assuntos
Adjuvantes Imunológicos , Bacillus/imunologia , Vírus da Influenza B/imunologia , Vacinas contra Influenza/imunologia , Vacinação/métodos , Animais , Anticorpos Antivirais/análise , Cobaias , Testes Sorológicos/métodosRESUMO
Satisfactory mucosal immunity in the respiratory tract is very important for protection against influenza. It can be achieved only by mucosal immunization. Mucosal vaccination with inactivated influenza virus may not be sufficiently effective and suitable adjuvants are therefore sought. We tested intratracheal immunization of mice with inactivate B type influenza virus in a mixture with formolized G+ bacterium Bacillus firmus, whose adjuvant effects have previously been documented in another system. The treatment resulted in a marked increase of both systemic and mucosal antibody response in IgG and IgA classes. Stimulation of T lymphocytes after adjuvant immunization was very mild, no proliferation taking place after specific stimulation with antigen in vitro. However, slightly increased systemic (spleen) and local (lungs) production of cytokines without perceptible Th1/Th2 polarization was determined. B. firmus is an efficient adjuvant in respiratory tract immunization while with subcutaneous immunization it lowers the antibody response.