Researchers have identified a protein that may prevent the flu from making people ill.
The protein, EP67, is known to enhance the immune system and currently is used in experimental flu vaccines to help activate the immune system.
But one researcher at San Diego State University saw greater potential. She wondered what would happen if you administered the protein after being exposed to the flu.
"The flu virus is very sneaky and actively keeps the immune system from detecting it for a few days until you are getting symptoms," said Joy Phillips, lead author and researcher at SDSU’s Donald P. Shiley BioScience Center. "Our research showed that introducing EP67 into the body within 24 hours of exposure to the flu virus caused the immune system to react almost immediately to the threat, well before your body normally would."
The research appears in today's journal of the Public Library of Science.
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The protein works by boosting or activating the immune system instead of just targeting the virus. That means it could be used against all flu viruses, not just the one or two circulating in any particular year. Current vaccines are made to target particular flu viruses and are less effective at preventing novel or different forms.
"When you find out you've been exposed to the flu, the only treatments available now target the virus directly, but they are not reliable and often, the virus develops a resistance against them," Phillips said. "EP67 could potentially be a therapeutic that someone would take when they know they've been exposed that would help the body fight off the virus before you get sick."
The protein might have broader applicability beyond just the flu – including novel respiratory viruses, such as SARS.
"The innate immune response works in a very generic fashion. It's like sending in the National Guard immediately after a disaster," Phillips said. "You get the immediate help at the site while you assess the situation and decide what specialists you need to bring in. In this case, it means that EP67-induced innate immunity is effective against bacteria and fungal infections, as well as acting as a broad-spectrum antiviral."
The current research was done on mice, but because people, mice and other animals share this same protein, it is likely that it will have similar effects in humans.
In this particular experiment, the researchers, including scientists from the University of Nebraska Medical Center, exposed a group of mice to the protein after they were exposed to a nonlethal form of influenza. It significantly reduced the level of weight loss seen in these mice. Weight loss is a mouse symptom of the flu.
In another case, the researchers exposed mice to a lethal form of the flu. None of the mice that were given the EP67 died. Those that hadn’t received the protein died. The effects of the protein, in both cases, were seen within two hours of receiving it.
Phillips said she’d now like to explore the protein’s effectiveness against other diseases, such as valley fever and Cryptococcus gattii, a disease that has been spreading throughout the Pacific Northwest and is particularly lethal for people with HIV or other immune-suppressing ailments.
She said EP67 is also likely to have effects in the fields of global health and bioterrorism.
"As an emergency therapeutic, EP67 has the potential to protect against a myriad of possible pathogens without needing to first identify any specific organism," she said, adding that she's also found it effective in other animals, such as chickens.