Despite serving as hosts to more than 100 types of viruses, bats remain largely unaffected by diseases because of how their immune systems are able to keep these pathogens at bay.

This innate ability of the winged mammals is what scientists are now trying to explore in the hopes of developing better protection for humans against deadly infections.

Researchers at the Commonwealth Scientific and Industrial Research Organization (CSIRO) are examining the immune system of Australian black flying foxes (Pteropus alecto) to find out how they are able to avoid getting sick from viruses that they carry.

These include disease-causing agents, such as Ebola and Middle Eastern Respiratory Syndrome (MERS) viruses, which have been proven deadly to humans.

Dr. Michelle Baker, a bat immunologist from the Australian Animal Health Laboratory, explained that they wanted to focus on the animals' innate immunity, particularly how proteins known as interferons are able to limit the spread of viruses.

What makes the immune system of bats interesting is that it only has three types of interferons, which is just a quarter of how many there are in the immune system of humans. However, the animals can still make themselves immune to most forms of viral infections that would otherwise be lethal to people.

Baker and her colleagues centered their research on two types of interferons in the bats: the alpha and the beta.

They discovered that the animals maintain a heightened natural immune response despite not being infected by any disease.

"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 defense against diseases," Baker said.

For most other mammals, having their immune systems activated at such a high rate would cause adverse effects, especially to their cells and tissues. However, this does not seem to be the case for the bats, whose immune system is able to operate in harmony with other bodily functions.

This innate trait among bats makes them a suitable subject for further research in order to develop treatments that would help raise the ability of humans to resist lethal infections.

Baker pointed out that if scientists could discover a way to redirect the immune responses of other species to perform similarly to how those of bats do, it could lower the high mortality rates caused by infectious diseases such as Ebola.

The findings of the CSIRO-led study are featured in the journal Proceedings of the National Academy of Sciences.

Photo: James Niland | Flickr