Protein that may boost survival of flu patients identified

Scientists have identified a protein that may improve lung function and boost survival rates in patients of influenza.
The protein GM-CSF modifies the immune response to the flu, and may also help reduce lung inflammation.
The researchers from Pennsylvania State University in the US studied the survival and lung function of mice with influenza in the lab.
They found that the mice that had been given large amounts of a special cytokine - molecules that warn other cells that there is an infection or other trauma in the body - called GM-CSF, had better survival and lung function than the other mice.

The results, published in the journal Respiratory Research, suggests that GM-CSF could be a potential therapeutic strategy for treating the flu.
"Previous research has shown that mice with naturally higher levels of GM-CSF might be protected from the flu," said E Scott Halstead, assistant professor at Pennsylvania State University.

"We gave the mice GM-CSF after they got the flu, which is more similar to when a patient gets sick and then you do something to help them. Even after they got the virus, it still helped," said Halstead.
While all viruses trigger a cytokine response in the body, Halstead said influenza tends to create a surge in a particular cytokine called type II interferon, which may be why influenza can be worse than other such viruses as rhinovirus or respiratory syncytial virus (RSV).

Type II interferon is associated with high levels of inflammation in the lungs.
Previous studies demonstrated that mice born with higher levels of GM-CSF were naturally protected from influenza, However, the researchers wanted to know if introducing GM-CSF after the mice already had the flu was just as effective.
Researchers used mice born with a special gene that allows them to create GM-CSF in their lungs when given the antibiotic doxycycline.
Three days after giving them influenza, the researchers gave the mice a dose of doxycycline, triggering the production of GM-CSF in the mice's lungs.
The researchers found that the mice with GM-CSF had a better chance of survival than the other mice.

At 13 days post-infection, 90 per cent of the mice with GM-CSF were still alive versus 50 per cent of the mice without.
"Many anti-virals out there, like Tamiflu, can only be given in the first day or two of infection. Most of the time, by the time you see the patient, it's too late for those medications," Halstead said.
"Our study showed that with GM-CSF, there might be a larger window of time," he said.