Secondary structural analysis of the mRNA regions encoding the hemagglutinin cleavage site basic amino acids of the avian influenza virus H5N1 subtype samples

Here we report the codon bias and the mRNA secondary structural features of the hemagglutinin (HA) cleavage site basic amino acid regions of avian influenza virus H5N1 subtypes. We have developed a dynamic extended folding strategy to predict RNA secondar

Avian influenza virus infection induces differential expression of genes in chicken kidney

The pathogenic process of highly pathogenic avian influenza virus (HPAIV) infection is poorly understood. To explore the differential expression of kidney genes as a result of HPAIV infection, two cDNA libraries were constructed from uninfected and infected kidneys by suppression subtractive hybridization (SSH). Fifteen genes including IFN-stimulated genes (ISG12), lymphocyte antigen 6 complex locus E gene (LY6E), matrix Gla protein gene (MGP), lysozyme gene, haemopoiesis related membrane protein I gene, KIAA1259, MGC68696, G6pe-prov protein gene (G6PC), MGC4504, alcohol dehydrogenase gene (ADH), glutathione S-transferase gene (GST), sodium-dependent high-affinity dicarboxylate transporter gene (SDCT), Synaptotagmin XV (SytXV) and two novel genes were found significantly up-regulated or dramatically suppressed. Differential expression of these genes was further identified by Northern blot. Functional analysis indicated that the regulation of their expression might contribute to the pathogenic process of HPAIV infection. In contrast, the increased expression of three IFN-stimulated genes named ISG12, LY6E, and haemopoiesis related membrane protein 1 gene might reflect host defense responses. Further study showed that ISG12 protein failed to directly interact with NS1 protein of HPAIV which expressed simultaneously in the organs where HPAIV replication occurred, by use of BacterioMatch two-hybrid system. Therefore, our findings may provide new insights into understanding the molecular mechanism underlying the pathophysiological process of HPAIV infection in chicken. (c) 2007 Elsevier Ltd. All rights reserved.

Detection of avian influenza virus subtype H5 using a biosensor based on imaging ellipsometry

A novel method is reported for the detection of avian influenza virus subtype H5 using a biosensor based on high spatial resolution imaging ellipsometry (IE). Monoclonal antibodies specific to H5 hemagglutinin protein were immobilized on silicon wafers and used to capture virus particles. Resultant changes on the surface of the wafers were visualized directly in gray-scale on an imaging ellipsometry image. This preliminary study has shown that the assay is rapid and specific for the identification of avian influenza virus subtype H5. Compared with lateral-flow immunoassays, this biosensor not only has better sensitivity, but can also simultaneously perform multiplexed tests. These results suggest that this biosensor might be a valuable diagnostic toot for avian influenza virus detection. (c) 2009 Elsevier B.V. All rights reserved.

H5N1 avian influenza re-emergence of Lake Communication Qinghai: phylogenetic and antigenic analyses of the newly isolated viruses and roles of migratory birds in virus circulation

Highly pathogenic avian influenza H5N1 virus has swept west across the globe and caused serious debates on the roles of migratory birds in virus circulation since the first large-scale outbreak in migratory birds of Lake Qinghai, 2005. In May 2006, another outbreak struck Lake Qinghai and six novel strains were isolated. To elucidate these QH06 viruses, the six isolates were subjected to whole-genome sequencing. Phylogenetic analyses show that QH06 viruses are derived from the lineages of Lake Qinghai, 2005. Five of the six novel isolates are adjacent to the strain A/Cygnus olor/Croatia/1/05, and the last one is related to the strain A/duck/Novosibirsk/ 02/05, an isolate of the flyway. Antigenic analyses suggest that QH06 and QH05 viruses are similar to each other. These findings implicate that QH06 viruses of Lake Qinghai may travel back via migratory birds, though not ruling out the possibility of local circulation of viruses of Lake Qinghai.