Jesse Bloom, Ph.D., is an assistant member of the Basic Sciences Division and Kathryn Hooper is a graduate research assistant in Bloom's lab at Fred Hutchinson Cancer Research Center. Credit: Fred Hutchinson Cancer Research Center
Scientists at Fred Hutchinson Cancer Research Center have uncovered a new mechanism by which influenza can infect cells – a finding that ultimately may have implications for immunity against the flu.
Influenza viruses have two main proteins on their surface that allow them to do their dirty work: a protein called hemagglutinin allows viruses to infect cells, while a protein called neuraminidase allows viruses to escape from cells.
Now in a paper published online ahead of the December print issue of the Journal of Virology , Jesse Bloom, Ph.D., an evolutionary biologist and assistant member of the Fred Hutch Basic Sciences Division, and Kathryn Hooper, a graduate research assistant in the Bloom Lab, describe the discovery of an influenza virus that instead uses neuraminidase to attach to cells.
The researchers discovered the new mechanism of infection after mutating the hemagglutinin of a lab-adapted strain of influenza so that it could no longer attach to cells.
"We expected that viruses with the mutated hemagglutinin wouldn't be able to infect cells," said Bloom, who also is a computational biologist and an assistant member of the Fred Hutch Public Health Sciences Division. "So we were surprised when a virus with this hemagglutinin started to grow. We were even more surprised when we sequenced the virus and discovered that it had evolved a mutation in neuraminidase."
Hooper began characterizing the new virus in detail. She discovered that the mutation allowed neuraminidase to attach the virus to cells. Hemagglutinin's ability to bind to cells – long considered one of the protein's most crucial and conserved properties – was no longer necessary for infection.
What does this finding mean for influenza in humans? That remains an open question, but Bloom and Hooper have already shown that the neuraminidase mutation they discovered is present in some human isolates of influenza.
"This was not a mutation we expected to find in the lab, let alone in viruses that have infected humans over the past few years," Hooper said. "It suggests there is influenza circulating in nature that may be infecting cells by a mechanism that has been overlooked by others in the field."
The researchers are now carefully characterizing human influenza isolates that have the mutation. They are also looking for other mutations that allow neuraminidase to attach viruses to cells.
They say there is a possibility that these types of mutations may have implications for immunity against influenza, since they might enable the virus to escape from antibodies that block the binding of hemagglutinin to cells.
Explore further: Researchers suggest boosting body's natural flu killers
Medical Xpress on facebook
Related Stories
Researchers suggest boosting body's natural flu killers
May 23, 2013
A known difficulty in fighting influenza (flu) is the ability of the flu viruses to mutate and thus evade various medications that were previously found to be effective. Researchers at the Hebrew University of Jerusalem have ...
Why do some influenza virus subtypes die out?
Nov 14, 2011
Every so often we hear about a new strain of influenza virus which has appeared and in some cases may sweep across the globe in a pandemic, much as the H1N1 virus did last year. What happens to the old seasonal viruses? In ...
New bird flu strain seen adapting to mammals, humans
Apr 12, 2013
A genetic analysis of the avian flu virus responsible for at least nine human deaths in China portrays a virus evolving to adapt to human cells, raising concern about its potential to spark a new global flu pandemic.
Novel avian influenza A virus has potential for both virulence and transmissibility in humans
Sep 10, 2013
A new study has found that a novel avian-origin H7N9 influenza A virus, which has recently emerged in humans, attaches moderately or abundantly to the epithelium of both the upper and lower respiratory tracts. This pattern ...
Source identification of H7N9 influenza virus causing human infections
Apr 25, 2013
In March 2013, a novel H7N9 influenza virus was identified in China as the etiological agent of a flu-like disease in humans, resulting in some deaths. A group of scientists, led by Professor Chen Hualan (National Avian Influenza ...
Recommended for you
Data from across globe defines distinct Kawasaki disease season
20 minutes ago
After more than four decades of research, strong evidence now shows that Kawasaki disease has a distinct seasonal occurrence shared by regions across the Northern hemisphere.
Booster dose of new meningitis vaccine may be beneficial
2 hours ago
A study of 4CMenB, a new vaccine to protect against meningitis B bacteria (which can cause potentially fatal bacterial meningitis in children), shows that waning immunity induced by infant vaccination can be overcome by a ...
Study reveals that preventing malaria in travelers to West Africa reduces health costs
3 hours ago
Not only do U.S. travelers to West Africa who consult health providers before they leave and take prescribed preventive medications substantially reduce their risk of contracting malaria, they also reduce costs to their health ...
'Superbug' MRSA infections aren't dropping in children: CDC
4 hours ago
(HealthDay)—Although rates of infection with methicillin-resistant staphylococcus aureus (MRSA) are declining among American adults, the rates among children remain largely unchanged, a new government study ...
Landmark study provides key to improved survival in peritoneal dialysis patients
5 hours ago
Clinicians and scientists from Keele and Cardiff universities have published data from a landmark study that explains why survival in patients on peritoneal dialysis is low.
When bacteria fight back
5 hours ago
The U.S. Centers for Disease Control and Prevention (CDC) has issued a report about the growth of drug-resistant bacteria in this country, saying that each year more than 23,000 people die and 2 million are ...
User comments
© Medical Xpress 2011-2013, Phys.org network
Jesse Bloom, Ph.D., is an assistant member of the Basic Sciences Division and Kathryn Hooper is a graduate research assistant in Bloom's lab at Fred Hutchinson Cancer Research Center. Credit: Fred Hutchinson Cancer Research Center
Scientists at Fred Hutchinson Cancer Research Center have uncovered a new mechanism by which influenza can infect cells – a finding that ultimately may have implications for immunity against the flu.
Influenza viruses have two main proteins on their surface that allow them to do their dirty work: a protein called hemagglutinin allows viruses to infect cells, while a protein called neuraminidase allows viruses to escape from cells.
Now in a paper published online ahead of the December print issue of the Journal of Virology , Jesse Bloom, Ph.D., an evolutionary biologist and assistant member of the Fred Hutch Basic Sciences Division, and Kathryn Hooper, a graduate research assistant in the Bloom Lab, describe the discovery of an influenza virus that instead uses neuraminidase to attach to cells.
The researchers discovered the new mechanism of infection after mutating the hemagglutinin of a lab-adapted strain of influenza so that it could no longer attach to cells.
"We expected that viruses with the mutated hemagglutinin wouldn't be able to infect cells," said Bloom, who also is a computational biologist and an assistant member of the Fred Hutch Public Health Sciences Division. "So we were surprised when a virus with this hemagglutinin started to grow. We were even more surprised when we sequenced the virus and discovered that it had evolved a mutation in neuraminidase."
Hooper began characterizing the new virus in detail. She discovered that the mutation allowed neuraminidase to attach the virus to cells. Hemagglutinin's ability to bind to cells – long considered one of the protein's most crucial and conserved properties – was no longer necessary for infection.
What does this finding mean for influenza in humans? That remains an open question, but Bloom and Hooper have already shown that the neuraminidase mutation they discovered is present in some human isolates of influenza.
"This was not a mutation we expected to find in the lab, let alone in viruses that have infected humans over the past few years," Hooper said. "It suggests there is influenza circulating in nature that may be infecting cells by a mechanism that has been overlooked by others in the field."
The researchers are now carefully characterizing human influenza isolates that have the mutation. They are also looking for other mutations that allow neuraminidase to attach viruses to cells.
They say there is a possibility that these types of mutations may have implications for immunity against influenza, since they might enable the virus to escape from antibodies that block the binding of hemagglutinin to cells.
Explore further: Researchers suggest boosting body's natural flu killers
Medical Xpress on facebook
Related Stories
Researchers suggest boosting body's natural flu killers
May 23, 2013
A known difficulty in fighting influenza (flu) is the ability of the flu viruses to mutate and thus evade various medications that were previously found to be effective. Researchers at the Hebrew University of Jerusalem have ...
Why do some influenza virus subtypes die out?
Nov 14, 2011
Every so often we hear about a new strain of influenza virus which has appeared and in some cases may sweep across the globe in a pandemic, much as the H1N1 virus did last year. What happens to the old seasonal viruses? In ...
New bird flu strain seen adapting to mammals, humans
Apr 12, 2013
A genetic analysis of the avian flu virus responsible for at least nine human deaths in China portrays a virus evolving to adapt to human cells, raising concern about its potential to spark a new global flu pandemic.
Novel avian influenza A virus has potential for both virulence and transmissibility in humans
Sep 10, 2013
A new study has found that a novel avian-origin H7N9 influenza A virus, which has recently emerged in humans, attaches moderately or abundantly to the epithelium of both the upper and lower respiratory tracts. This pattern ...
Source identification of H7N9 influenza virus causing human infections
Apr 25, 2013
In March 2013, a novel H7N9 influenza virus was identified in China as the etiological agent of a flu-like disease in humans, resulting in some deaths. A group of scientists, led by Professor Chen Hualan (National Avian Influenza ...
Recommended for you
Data from across globe defines distinct Kawasaki disease season
20 minutes ago
After more than four decades of research, strong evidence now shows that Kawasaki disease has a distinct seasonal occurrence shared by regions across the Northern hemisphere.
Booster dose of new meningitis vaccine may be beneficial
2 hours ago
A study of 4CMenB, a new vaccine to protect against meningitis B bacteria (which can cause potentially fatal bacterial meningitis in children), shows that waning immunity induced by infant vaccination can be overcome by a ...
Study reveals that preventing malaria in travelers to West Africa reduces health costs
3 hours ago
Not only do U.S. travelers to West Africa who consult health providers before they leave and take prescribed preventive medications substantially reduce their risk of contracting malaria, they also reduce costs to their health ...
'Superbug' MRSA infections aren't dropping in children: CDC
4 hours ago
(HealthDay)—Although rates of infection with methicillin-resistant staphylococcus aureus (MRSA) are declining among American adults, the rates among children remain largely unchanged, a new government study ...
Landmark study provides key to improved survival in peritoneal dialysis patients
5 hours ago
Clinicians and scientists from Keele and Cardiff universities have published data from a landmark study that explains why survival in patients on peritoneal dialysis is low.
When bacteria fight back
5 hours ago
The U.S. Centers for Disease Control and Prevention (CDC) has issued a report about the growth of drug-resistant bacteria in this country, saying that each year more than 23,000 people die and 2 million are ...
User comments
© Medical Xpress 2011-2013, Phys.org network
0 comments:
Post a Comment