Growth determinants for H5N1 influenza vaccine seed viruses in MDCK cells

[Sally Furniss]

Growth determinants for H5N1 influenza vaccine seed viruses in MDCK cells

<nobr>Shin Murakami,</nobr> <nobr>Taisuke Horimoto^*,</nobr> <nobr>Le Quynh Mai,</nobr> <nobr>Chairul A. Nidom,</nobr> <nobr>Hualan Chen,</nobr> <nobr>Yukiko Muramoto,</nobr> <nobr>Shinya Yamada,</nobr> <nobr>Ayaka Iwasa,</nobr> <nobr>Kiyoko Iwatsuki-Horimoto,</nobr> <nobr>Masayuki Shimojima,</nobr> <nobr>Akira Iwata,</nobr> and <nobr>Yoshihiro Kawaoka<sup>*

</sup></nobr> Division of Virology, Department of Microbiology and Immunology, and International Research Center for Infectious Diseases, Institute of Medical Science, University of Tokyo, Tokyo, Japan; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency, Saitama, Japan; National Institute of Hygiene and Epidemiology, Hanoi, Vietnam, Avian Influenza Laboratory, Tropical Disease Centre, Airlangga University, Surabaya, Indonesia; Animal Influenza Laboratory of the Ministry of Agriculture and National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China; Nippon Institute for Biological Science, Tokyo, Japan; Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin


[SIZE=-1] ^* To whom correspondence should be addressed. Email: horimoto@ims.u-tokyo.ac.jp<script type="text/javascript"><!-- var u = "horimoto", d = "ims.u-tokyo.ac.jp"; document.getElementById("em0").innerHTML = '<a href="mailto:' + u + '@' + d + '">' + u + '@' + d + '<\/a>'//--></script>. kawaoka@ims.u-tokyo.ac.jp<script type="text/javascript"><!-- var u = "kawaoka", d = "ims.u-tokyo.ac.jp"; document.getElementById("em1").innerHTML = '<a href="mailto:' + u + '@' + d + '">' + u + '@' + d + '<\/a>'//--></script>.
[/SIZE]
[SIZE=-1]
[/SIZE]
<!-- null -->
<table bgcolor="#e1e1e1" cellpadding="0" cellspacing="0" width="100%"> <tbody><tr><td align="left" bgcolor="#ffffff" valign="middle" width="5%">

</td> <th align="left" valign="middle" width="95%">[SIZE=+2] Abstract[/SIZE]</th></tr></tbody></table>
H5N1 influenza A viruses are exacting a growing human toll,with more than 240 fatal cases to date. In the event of an influenzapandemic by these viruses, embryonated chicken eggs, which arethe approved substrate for human inactivated vaccine production,will likely be in short supply because chickens will be killedby these viruses or culled to limit the worldwide spread ofthe infection.

The Madin-Darby canine kidney (MDCK) cell lineis a promising alternative candidate substrate because it supportsefficient growth of influenza viruses compared to other celllines.

Here, we addressed the molecular determinants for growthof an H5N1 vaccine seed virus in MDCK cells, revealing the criticalresponsibility of the Tyr residue at position 360 of PB2, theconsiderable requirement for functional balance between hemagglutinin(HA) and neuraminidase (NA), and the partial responsibilityof the Glu residue at position 55 of NS1.

Based on these findings,we produced a PR8/H5N1 reassortant, optimized for this cellline, that derives all of its genes for its internal proteinsfrom the PR8(UW) strain except for the NS gene, which derivesfrom the PR8(Cambridge) strain, its N1 NA with a long stalkfrom an early H5N1 strain, and its HA with an avirulent-typecleavage site sequence derived from a circulating H5N1 virus.
Our findings demonstrate the importance and feasibility of acell-culture based approach to producing seed viruses for H5N1inactivated vaccines that grow robustly and in a timely, cost-efficientmanner as an alternative to egg-based vaccine production.

http://kyxk.net/bbscon.php?board=Paper&id=11928&ap=278