title: Changes in the NS1 gene of avian influenza viruses isolated in Thailand affect expression of type I interferon in primary chicken embryonic fibroblast cells.
abstract: The non-structural protein 1 (NS1) of avian influenza virus was defined as one of the virulent factors. To understand the effect of NS1 protein of influenza virus H5N1 isolated in Thailand on type I (α/β) interferon (IFN) synthesis, five reverse genetic viruses were constructed and used as models. The viruses were generated using NS genomic segment from A/Peurto Rico/8/1934 (H1N1) and four avian influenza viruses isolated from the first outbreak in Thailand. All the viruses have the rest of the genome from A/Peurto Rico/8/1934 (H1N1). The constructed viruses were named (1) NS1 PR8/34, (2) NS1 wild type, (3) NS1 L15FD53G, (4) NS1 N171I and (5) NS1 E71K, respectively. The type I (α/β) IFN gene expression in control and infected primary chicken embryonic fibroblast cells were analyzed by quantitative polymerase chain reaction. The results show that the inhibition of IFN-β gene expression by NS1 wild type infected cells is stronger than NS1 N171I, NS1 E71K, NS1 PR8/34 and NS1 L15FD53G, respectively. The data suggest that the difference of amino acid sequence of NS1 protein contributes to the IFN-β antagonist. In contrast, the difference of the NS1 protein does not influence in the IFN-α antagonistic activity.
authors.affiliation: Department of Biochemistry, Faculty of Medical Sciences, Naresuan University, Phitsanulok, 65000 Thailand ; Department of Biochemistry, Faculty of Medical Sciences, University of Phayao, Phayao, 56000 Thailand.
authors.forename: Chutamas
authors.initials: C
authors.lastname: Thepmalee
authors.affiliation: Department of Biochemistry, Faculty of Medical Sciences, Naresuan University, Phitsanulok, 65000 Thailand.
authors.forename: Phanchana
authors.initials: P
authors.lastname: Sanguansermsri
authors.affiliation: Department of Biochemistry, Faculty of Medical Sciences, Naresuan University, Phitsanulok, 65000 Thailand ; Department of Biology, Faculty of Sciences, University of Phayao, Phayao, 56000 Thailand.
authors.forename: Naratchala
authors.initials: N
authors.lastname: Suwanankhon
authors.affiliation: Veterinary Research and Development Centre Lower Northern Region, Phitsanulok, 65130 Thailand.
authors.forename: Chanpen
authors.initials: C
authors.lastname: Chamnanpood
authors.affiliation: Regional Livestock Office 6th, Phitsanulok, 65000 Thailand.
authors.forename: Pornchai
authors.initials: P
authors.lastname: Chamnanpood
authors.affiliation: Department of Medicine, Faculty of Medicine, Naresuan University, Phitsanulok, 65000 Thailand.
authors.forename: Sutatip
authors.initials: S
authors.lastname: Pongcharoen
authors.affiliation: Department of Microbiology and Parasitology, Faculty of Medical Sciences, Naresuan University, Phitsanulok, 65000 Thailand.
authors.forename: Pannika R
authors.initials: PR
authors.lastname: Niumsap
authors.affiliation: Department of Biochemistry, Faculty of Medical Sciences, Naresuan University, Phitsanulok, 65000 Thailand.
authors.forename: Damratsamon
authors.initials: D
authors.lastname: Surangkul
authors.affiliation: Department of Microbiology and Parasitology, Faculty of Medical Sciences, Naresuan University, Phitsanulok, 65000 Thailand ; Centre of Excellence in Medical Biotechnology, Faculty of Medical Sciences, Naresuan University, Phitsanulok, 65000 Thailand.
authors.forename: Donruedee
authors.initials: D
authors.lastname: Sanguansermsri
keywords: Avian influenza virus; H5N1; Non structural 1 protein; Reverse genetic virus; Type I interferon