Bat influenza viruses – what do we know and what do we need to know?
A distinct lineage of bat influenza viruses was first reported in 2012. The discovery of bat flu viruses raised a lot of questions about the ability of these viruses to infect other mammals. Studies have now identified that bat flu viruses (H17N10 and H18N11) can infect cells that express human, bat, chicken and pig versions of the virus receptor. These data suggest that in theory, bat flu viruses may be able to infect humans, chickens and pigs. The good news – experimental infections in mice and ferrets have shown that although these animals can be infected with bat influenza viruses, infected animals are unable to transmit to other experimental animals. Thus, bat flu viruses have not acquired the ability to efficiently transmit from ferrets-to-ferrets and mice-to-mice. However, bat flu viruses did transmit from infected bats to uninfected bats in the same study.
Most importantly, recent studies have identified the receptor that allows bat influenza viruses to enter cells and multiply. This receptor is a critical player in our immune response – Major histocompatibility complex class II (MHCII). The immunological consequences of using this receptor for entering mammalian cells have not been studied yet. Future studies will identify the effect of MHC-II-mediated virus entry on host immune responses, and the ability of bat flu viruses to modulate antiviral responses. We also do not know how bats respond to their own flu viruses. Do they become sick? Do they quickly recover and mount a protective immune response? How do bat populations maintain influenza viruses? Can we learn from bats to harness their immunity strategy for our own benefit? There are many questions that remain unanswered…
“The discovery and ongoing characterization of bat influenza viruses highlights the unpredictable nature of these viruses and the need for more intense study of their evolutionary diversity and pathobiology, especially in non-human hosts”
Read our full scientific forum discussion here.
Picture credit: Dr. Brock Fenton
