RESUMO
Two human Fab antibodies against avian influenza A (H5N1) virus were obtained by panning a H5N1 patient-derived antibody phage library using purified virions of the H5N1 patient isolate A/Anhui/1/2005 and HA protein of the H5N1 reference viruse A/Viet Nam/1203/2004. After testing the binding properties and antiviral function to H5N1 virus, the selected Fab antibodies were converted to full human IgG antibodies with recombinant baculovirus/insect cell system. Both mAbs, AVFluIgG01 and AVFluIgG03, bound to HA in immunofluorescence assay (IFA) without cross-reaction with the other substypes of influenza A viruses (H1N1, H3N2). The cross-reactivity of the two antibodies for different strains of H5N1 was tested in vitro by micro-neutralization assays. In vitro, mAb AVFluIgG01 potently neutralized not only the selected well-characterized Clade 2 H5N1 viruses isolated from mainland of China except A/Guangdong/1/2006, but also the Clade 1 representative isolate A/Viet Nam/1203/2004; and AVFluIgG03 neutralized all the selected Clade 2 H5N1 viruses isolated from mainland of China, but had no neutralizing activity with the Clade 1 H5N1 virus A/Viet Nam/1203/2004. The results bring new prospect for the prophylaxis or treatment of H5N1 virus infection and may provide a clue for novel vaccine development.
Assuntos
Animais , Humanos , Sequência de Aminoácidos , Anticorpos Antivirais , Genética , Alergia e Imunologia , Especificidade de Anticorpos , Aves , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Virus da Influenza A Subtipo H5N1 , Genética , Alergia e Imunologia , Vacinas contra Influenza , Genética , Alergia e Imunologia , Influenza Aviária , Alergia e Imunologia , Virologia , Dados de Sequência Molecular , Testes de Neutralização , Proteínas Recombinantes , Alergia e Imunologia , Homologia de Sequência de AminoácidosRESUMO
<p><b>OBJECTIVE</b>To identify genes in human cells infected with high pathogenic avian influenza viruses H5N1.</p><p><b>METHODS</b>The lung carcinoma cells line A549 was infected with H5N1 and H1N1, respectively. We harvested the infected cells at the different time points after infection and screened the genes with differential expression via microarray technology. The candidate genes were selected and confirmed by quantitative real-time PCR.</p><p><b>RESULTS</b>The spectrum of genes with the differential expression in the cells infected with H5N1 was obtained and 16 candidate genes were identified in the cellular apoptosis pathway, mTOR pathway, and the cellular immunity as well.</p><p><b>CONCLUSIONS</b>Our results suggest that H5N1 exert a stronger impact on eliciting apoptosis of infected cells than the common influenza virus H1N1.</p>