Bats can fly and host viruses that are deadly to humans. What's the connection?

When I was a kid, I used to see bats as otherworldly creatures that could turn into vampires. Although I still cannot prove whether this is true or not, today I learned that bats are curiously weirdos. Scientists have discovered that bats carry a mutation in an immune (defence) protein, named STING. This mutation tentatively explains how bats can cope with the metabolic rates required for flying but also can carry, without disease symptoms, viruses that are rather deadly to humans. To explain this better, let's divide the cells into two compartments: cytoplasm and nucleus. DNA (the genetic material) is restricted to the nucleus and inside mitochondria (cytoplasmic organelles). This means no DNA should be found outside of these compartments. If for some reason this happens, this out-of-place DNA would indicate to the cells that stress or viral infection is taking place and the cells would respond to it by activating defence mechanisms (including cellular suicide!). Bats have not taken immunology classes and therefore present lots of mislocalized DNA in their cytoplasm due to their metabolic conditions that allow them to fly. This out-of-place DNA is not sensed in bats because their STING protein (mentioned above) contains a mutation that prevents its "overreaction". Viruses take advantage of this and survive within bats without being recognised as intruders. These findings pave the way for further studies that could help to explain how bats can host and transmit viruses that are life-threatening to humans.

Link to the original manuscript: http://www.cell.com/cell-host-microbe/fulltext/S1931-3128(18)30041-6