Tracking a moving target
Figure 1: The molecular structure of hemagglutinin (HA), where D185 shows the part of the protein that was mutated in severe cases of flu infection. Credit: 2011 J.-É. Morlighem et al.
The influenza pandemic that began in Mexico in April 2009 rapidly spread throughout the world and arrived in Japan one month later. Now, a research team led by Toshihisa Ishikawa at the RIKEN Omics Science Center in Yokohama has revealed what a portion of the pandemic influenza virus looked like when it emerged in Japan (Fig. 1), and how it has changed over time. The findings will help to guide influenza vaccine development and will aid in preparations for future influenza pandemic outbreaks.
The researchers collected swab samples from the respiratory system of 253 individual flu sufferers in Osaka, Tokyo and Chiba, and sequenced the influenza genes encoding the proteins hemagglutinin (HA) and neuraminidase (NA). Although these genes represent only 10% of the influenza viral genome, they demonstrate more variability than other influenza genes, Ishikawa explains, so are likely to mediate any emerging changes in flu severity or antiviral drug resistance.
The sequencing showed that the pandemic influenza samples from the individuals in Japan fell into two groups: those that were collected at the time of the initial outbreak in May 2009, and those that were collected a few months later, during the most rapid spread of the virus throughout the country from October 2009 to January 2010.
Importantly, when the researchers compared the sequences between these two groups of viruses, they found that they fell into two totally separate clusters. This indicated that there were many differences between the two groups of pandemic influenza viruses, including the emergence of a mutation in an important sitethe so-called Ca antigen site of HAthat is known to be subject to pressure by the immune system. This mutation, as well as some others that the researchers identified, may account for the more rapid spread of the pandemic influenza virus later in the year.
Ishikawa and colleagues also found other mutations in the Ca antigen site of HA that conferred a more severe disease course, as well as mutations in NA that led to resistance to currently available antiviral drugs.
The rapid emergence of these mutations suggests that the 2009 pandemic influenza viruses have a genome with an extremely high evolutionary rate, says Ishikawa. Moreover, the mutated viruses seemed to rapidly circulate around Japan via modern traffic networks, he explains. These characteristics of the virus and its spread are important factors to consider when designing future vaccines or when deciding how best to slow any future influenza pandemic outbreaks.
More information: Morlighem, J.-É., et al. Mutation analysis of 2009 pandemic influenza A(H1N1) viruses collected in Japan during the peak phase of the pandemic. PLoS ONE 6, e18956 (2011).
Provided by RIKEN
- New study sheds light on evolution of 2009 pandemic influenza A(H1N1) virus in Japan Apr 25, 2011 | not rated yet | 0
- Origins of the pandemic: Study reveals lessons of H1N1 Jan 13, 2011 | not rated yet | 0
- Ыcientists explore 1510 influenza pandemic and lessons learned Nov 12, 2010 | not rated yet | 0
- NIH experts describe influenza vaccines of the future Nov 17, 2010 | not rated yet | 0
- Pandemic mutations in bird flu revealed Jul 09, 2008 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Classical and Quantum Mechanics via Lie algebras
Apr 15, 2011 I'd like to open a discussion thread for version 2 of the draft of my book ''Classical and Quantum Mechanics via Lie algebras'', available online at http://lanl.arxiv.org/abs/0810.1019 , and for the...
- More from Physics Forums - Independent Research
More news stories
Gourmands and foodies everywhere have long recognized ginger as a great way to add a little peppery zing to both sweet and savory dishes; now, a study from researchers at Columbia University shows purified components of the ...
Diseases, Conditions, Syndromes 2 hours ago | not rated yet | 0
There are significant cost and risk factors associated with two procedures commonly used to diagnose or treat gastrointestinal problems, according to research presented at Digestive Disease Week (DDW).
Diseases, Conditions, Syndromes 14 hours ago | not rated yet | 0
Regular consumption of coffee is associated with a reduced risk of primary sclerosing cholangitis (PSC), an autoimmune liver disease, Mayo Clinic research shows. The findings were being presented at the Digestive Disease ...
Diseases, Conditions, Syndromes 14 hours ago | not rated yet | 0 |
A new case of the deadly coronavirus has been detected in Saudi Arabia where 15 people have already died after contracting it, the health ministry announced on Saturday on its Internet website.
Diseases, Conditions, Syndromes May 18, 2013 | not rated yet | 0
(HealthDay)—Few randomized clinical trials have been done to assess clinical prediction rules for patients with lower back pain, and the trials that have been done are of low quality and do not provide ...
Diseases, Conditions, Syndromes May 17, 2013 | not rated yet | 0 |
Researchers at the University of Wisconsin have identified a potential new risk factor for obstructive sleep apnea: asthma. Using data from the National Institutes of Health (Heart, Lung, and Blood Institute)-funded Wisconsin ...
2 hours ago | not rated yet | 0 |
A new study looking at sleep-disordered breathing (SDB) and markers for Alzheimer's disease (AD) risk in cerebrospinal fluid (CSF) and neuroimaging adds to the growing body of research linking the two.
2 hours ago | not rated yet | 0 |
In their quest to learn more about the variability of cells between and within tissues, biomedical scientists have devised tools capable of simultaneously measuring dozens of characteristics of individual ...
3 hours ago | 5 / 5 (1) | 0 |
Scientists at Johns Hopkins have turned their view of osteoarthritis (OA) inside out. Literally. Instead of seeing the painful degenerative disease as a problem primarily of the cartilage that cushions joints, ...
3 hours ago | 5 / 5 (1) | 0 |
The hunt for an HIV vaccine has gobbled up $8 billion in the past decade, and the failure of the most recent efficacy trial has delivered yet another setback to 26 years of efforts.
7 hours ago | not rated yet | 0
The devastating effect of Alzheimer's disease on bilingual people has been thrown into focus in Canada, where the sudden loss of a second language can leave sufferers feeling like strangers in their own country.
5 hours ago | not rated yet | 0