Researchers discover a new way that influenza can infect cells

September 23, 2013
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 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 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 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 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 to cells.

They say there is a possibility that these types of may have implications for immunity against , 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

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 ...

New bird flu strain seen adapting to mammals, humans

April 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

September 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

April 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 ...

Study puts troubling traits of H7N9 avian flu virus on display

July 10, 2013
The emerging H7N9 avian influenza virus responsible for at least 37 deaths in China has qualities that could potentially spark a global outbreak of flu, according to a new study published today (July 10, 2013) in the journal ...

Recommended for you

Testing shows differences in efficacy of Zika vaccines after one year

December 15, 2017
(Medical Xpress)—A large team of researchers with members from Harvard Medical School, Walter Reed Army Institute of Research, Bioqual Inc. and MIT has found that the efficacy of the three types of Zika vaccines currently ...

How to regulate fecal microbiota transplants

December 15, 2017
(Medical Xpress)—A small team of researchers at the University of Maryland, some with affiliations to the Veterans Affairs Maryland Health Care System, has written and published a Policy Forum piece in the journal Science ...

New cellular approach found to control progression of chronic kidney disease

December 15, 2017
Researchers have demonstrated for the first time that extracellular vesicles - tiny protein-filled structures - isolated from amniotic fluid stem cells (AFSCs) can be used to effectively slow the progression of kidney damage ...

Urine test developed to test for tuberculosis

December 14, 2017
(Medical Xpress)—An international team of researchers has developed a urine test that can be used to detect tuberculosis (TB) in human patients. In their paper published in Science Translational Medicine, the group describes ...

40 years after first Ebola outbreak, survivors show signs they can stave off new infection

December 14, 2017
Survivors of the first known Ebola outbreak, which occurred in the Democratic Republic of the Congo in 1976, may be key to development of vaccines and therapeutic drugs to treat future outbreaks, according to a new study ...

Aging impairs innate immune response to flu

December 13, 2017
Aging impairs the immune system's response to the flu virus in multiple ways, weakening resistance in older adults, according to a Yale study. The research reveals why older people are at increased risk of illness and death ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.