February 23, 2016
MARK COLVIN: Australian researchers have worked out how bats can remain unaffected by lethal viruses that kill other animals.
Bats naturally host deadly diseases like Ebola and Hendra virus.
Now a team at the CSIRO has shown how the animals manage the diseases by keeping their immune systems permanently switched on.
The discovery could be a key to developing a new way to treat viral infections.
Anthony Stewart reports
ANTHONY STEWART: It's a conundrum; how is it bats can house diseases which are deadly to humans like Ebola and Hendra and yet remain completely unaffected themselves?
(Sounds of bats screeching)
In fact bats naturally host up to 100 viruses without showing any of the health effects that kill other animals.
The CSIRO has today released a study on the genes used by black flying foxes to fight off viral infections.
Researcher James Wynne says the team focused on a protein all animals use to stop viruses, "interferons".
JAMES WYNNE: Their molecules that are up-regulated - as soon as any cell in your body is infected with a virus, these interferons are induced, they are secreted out of the cell and then they basically signal to all the other cells that we have a virus infection happening here; we need immune molecules or we need self-destruction mechanisms to try and eliminate the cell.
ANTHONY STEWART: In humans, these proteins only come into action when you get sick.
But the CSIRO team has discovered that in bats, they're permanently switched on.
JAMES WYNNE: But we showed that, you know, in bats these interferons are always up-regulated and what that means is they always have this heightened immune response.
ANTHONY STEWART: Does that explain why bats are able to coexist with deadly viruses that if humans get would kill us?
JAMES WYNNE: That's what we are getting at, and we think that it makes sense. If bats are able to coexist but still kind of subdue the viral infection enough that they are healthy but they still have the virus and then it can get spilt over to other species.
ANTHONY STEWART: Having the immune system constantly switched on is dangerous for humans; it's toxic to tissue and cells.
But CSIRO immunologist, Michelle Baker, is working out how bats manage this problem.
MICHELLE BAKER: If we can work out how bats are able to have it switched on without those negative consequences, I think that can certainly be translated into some sort of human therapeutic.
So the production of interferons are really the only first part of that anti-viral response. Interferon then actually results in the induction of a number of other genes that have various roles in controlling viruses and other pathogens.
So it's these downstream genes that we really need to pay attention to in the future - which genes are produced as a result of this high level of interferon alpha in bat cells, and what we've found so far is that the subset that's induced is not really toxic. It's a really less inflammatory subset of genes.
ANTHONY STEWART: Michelle Baker says the work could lead to new ways to treat viruses.
MICHELLE BAKER: I mean the hope is that we could find something that could perhaps help to control all sorts of viruses, but that's a little way off in the future.
ANTHONY STEWART: Control of viruses, I mean it's effectively you'd be finding a cure to the common cold if you could do something like this, wouldn't you?
MICHELLE BAKER: Oh, I know, it'd be brilliant wouldn't it?
ANTHONY STEWART: The CSIRO study was published in the proceedings of the National Academy of Science.
MARK COLVIN: Anthony Stewart reporting
Bats naturally host deadly diseases like Ebola and Hendra virus.
Now a team at the CSIRO has shown how the animals manage the diseases by keeping their immune systems permanently switched on.
The discovery could be a key to developing a new way to treat viral infections.
Anthony Stewart reports
ANTHONY STEWART: It's a conundrum; how is it bats can house diseases which are deadly to humans like Ebola and Hendra and yet remain completely unaffected themselves?
(Sounds of bats screeching)
In fact bats naturally host up to 100 viruses without showing any of the health effects that kill other animals.
The CSIRO has today released a study on the genes used by black flying foxes to fight off viral infections.
Researcher James Wynne says the team focused on a protein all animals use to stop viruses, "interferons".
JAMES WYNNE: Their molecules that are up-regulated - as soon as any cell in your body is infected with a virus, these interferons are induced, they are secreted out of the cell and then they basically signal to all the other cells that we have a virus infection happening here; we need immune molecules or we need self-destruction mechanisms to try and eliminate the cell.
ANTHONY STEWART: In humans, these proteins only come into action when you get sick.
But the CSIRO team has discovered that in bats, they're permanently switched on.
JAMES WYNNE: But we showed that, you know, in bats these interferons are always up-regulated and what that means is they always have this heightened immune response.
ANTHONY STEWART: Does that explain why bats are able to coexist with deadly viruses that if humans get would kill us?
JAMES WYNNE: That's what we are getting at, and we think that it makes sense. If bats are able to coexist but still kind of subdue the viral infection enough that they are healthy but they still have the virus and then it can get spilt over to other species.
ANTHONY STEWART: Having the immune system constantly switched on is dangerous for humans; it's toxic to tissue and cells.
But CSIRO immunologist, Michelle Baker, is working out how bats manage this problem.
MICHELLE BAKER: If we can work out how bats are able to have it switched on without those negative consequences, I think that can certainly be translated into some sort of human therapeutic.
So the production of interferons are really the only first part of that anti-viral response. Interferon then actually results in the induction of a number of other genes that have various roles in controlling viruses and other pathogens.
So it's these downstream genes that we really need to pay attention to in the future - which genes are produced as a result of this high level of interferon alpha in bat cells, and what we've found so far is that the subset that's induced is not really toxic. It's a really less inflammatory subset of genes.
ANTHONY STEWART: Michelle Baker says the work could lead to new ways to treat viruses.
MICHELLE BAKER: I mean the hope is that we could find something that could perhaps help to control all sorts of viruses, but that's a little way off in the future.
ANTHONY STEWART: Control of viruses, I mean it's effectively you'd be finding a cure to the common cold if you could do something like this, wouldn't you?
MICHELLE BAKER: Oh, I know, it'd be brilliant wouldn't it?
ANTHONY STEWART: The CSIRO study was published in the proceedings of the National Academy of Science.
MARK COLVIN: Anthony Stewart reporting
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