Press releases
Please quote Nature Biotechnology as the source of these items.
The February 2008 issue of Nature Biotechnology is available online.
February 2008
Anatomy of a pandemic flu threat
Widespread transmission of bird flu between humans would require the virus to develop the ability to recognize umbrella-shaped structures in the human respiratory tract. This finding, reported online this week in Nature Biotechnology, promises to change how scientists monitor human adaptation of flu viruses and how doctors diagnose and treat both seasonal influenza and a potential H5N1 pandemic.
Most human flu pandemics are thought to have arisen from mutant viruses that combine features of both animal and human influenzas, but knowing exactly what to look for when analyzing new variants is key to anticipating an outbreak. Flu viruses attack by binding sugar chains that line the airways and lungs. The chemical linkages between the sugar molecules in these chains differ between humans and birds, and until now it has been assumed that bird flu viruses adapt to humans simply by acquiring mutations that enable them to attach to human sugar linkages.
Ram Sasisekharan and colleagues show that human adaptation depends on the shape assumed by the flexible sugar chains rather than the type of linkage. Bird flu viruses currently require cone-shaped sugar chains to infect birds, so the umbrella shape found in humans has protected most of us from avian flu. One implication of this finding is that bird flu strains that might have triggered alarm may not be a cause for undue concern provided that they cannot bind umbrella-shaped sugar chains.
Glycan topology determines human adaptation of avian H5N1 virus hemagglutinin pp 107 - 113
Aarthi Chandrasekaran, Aravind Srinivasan, Rahul Raman, Karthik Viswanathan, S Raguram, Terrence M Tumpey, V Sasisekharan & Ram Sasisekharan
Published online: 6 January 2008 | doi 10.1038/nbt1375