Bats' super immunity may help protect people from Ebola

Bats keep their immune systems switched on 24/7 and can carry lethal viruses without being affected themselves, according to a new study that may hold the key to protecting people from deadly diseases like Ebola.
Bats are a natural host for more than 100 viruses, some of which are lethal to people, including Middle Eastern Respiratory Syndrome (MERS), Ebola and Hendra virus.
However, bats do not get sick or show signs of disease from these viruses, researchers said.
The research examined the genes and immune system of the Australian black flying fox.
"Whenever our body encounters a foreign organism, like bacteria or a virus, a complicated set of immune responses are set in motion, one of which is the defence mechanism known as innate immunity," said Michelle Baker from Commonwealth Scientific and Industrial Research Organisation (CSIRO)'s Australian Animal Health Laboratory.

"We focused on the innate immunity of bats, in particular the role of interferons - which are integral for innate immune responses in mammals - to understand what's special about how bats respond to invading viruses," said Baker.

"Interestingly we have shown that bats only have three interferons which is only a fraction - about a quarter - of the number of interferons we find in people," he said.
"This is surprising given bats have this unique ability to control viral infections that are lethal in people and yet they can do this with a lower number of interferons," Baker said.

The team also compared two type 1 interferons - alpha and beta.
The research showed that bats express a heightened innate immune response even when they were not infected with any detectable virus.
"Unlike people and mice, who activate their immune systems only in response to infection, the bats interferon-alpha is constantly 'switched on' acting as a 24/7 front line defence against diseases," Baker said.
"In other mammalian species, having the immune response constantly switched on is dangerous - for example it's toxic to tissue and cells - whereas the bat immune system operates in harmony," he said.
While we are familiar of the important role bats play in the eco-system as pollinators and insect controllers, they are also increasingly demonstrating their worth in potentially helping to protect people from infectious diseases.

"If we can redirect other species' immune responses to behave in a similar manner to that of bats, then the high death rate associated with diseases, such as Ebola, could be a thing of the past," Baker said.
The study was published in the journal PNAS.