Bats’ super-immunity could help protect people

Researchers have uncovered a unique ability in bats which allows them to carry but remain unaffected by lethal diseases. Unlike humans, bats keep their immune systems switched on 24/7 and scientists believe this could 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, but bats do not get sick or show signs of disease from these viruses.

Published today in the journal Proceedings of the National Academy of Sciences (PNAS), this new research examines the genes and immune system of the Australian black flying fox, with surprising results.

“Whenever our body encounters a foreign organism, like bacteria or a virus, a complicated set of immune responses is set in motion, one of which is the defense mechanism known as innate immunity,” leading bat immunologist at CSIRO’s Geelong-based Australian Animal Health Laboratory Dr Michelle Baker said.

“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.

“Interestingly, we have shown that bats only have three interferons, which is only about a quarter of the number of interferons we find in people.

“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.”

She said unlike people and mice, which activate their immune systems only in response to infection, a bat’s interferons are constantly switched on.

“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.

“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.”