After getting bitten by a bat bug at a recent conference. armin schoben I was itching to study bats, literally and figuratively. Blood-sucking insects are among the many parasites that haunt flying mammals and cause disease, but bats rarely get sick in the same way that humans do.
The mammalian immune system is rapidly evolving as the species is constantly exposed to new pathogens in the environment. “You’re constantly having to keep up with new bad guys trying to infect you and harm you,” says Schoeben, a postdoctoral fellow in population genomics at Cold Spring Harbor Laboratory (who has since been diagnosed with bite wounds). recovered). And while he studied genetic adaptations in some mammals, they pale in comparison to those that gave bats the ability to fight infectious diseases effectively.
In a new study published today, journal Genome biology and evolution, Schoeven and his team have identified genes that contribute to bats’ rapidly evolving immune systems and unique ability to evade deadly viruses and even cancer. Understanding how bats overcome disease could lead to new immunotherapy treatments for humans and help prevent new pandemics.
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The authors analyzed the DNA of 15 different bat species to get a clearer picture of how bat genes have evolved over time. They completely sequenced the genomes of two bat species, the Jamaican free-tailed bat and the Mesoamerican bearded bat, and collected other species from existing datasets.
They then compared the bat genome with those of humans, mice and other cancer-prone mammals, focusing on sequences that code for proteins involved in causing or preventing the disease. First, we lined up homologous genes, or genes shared between different species that were inherited from a common evolutionary ancestor. (It’s like comparing apples to apples, Scheben explains.) For each homologous gene, he hypothesized two scenarios: if bats lost it or if it mutated. If flying mammals were to completely lose the gene, that would suggest that its deletion is important in fighting disease. But if subtle changes in DNA sequences found only in bats remain, they could indicate changes in gene function that somehow help keep the population healthy.
Ultimately, the most significant changes the researchers detected were in the type 1 interferon (IFN) gene, which is important in controlling the inflammatory response to infection. Specifically, changes in the number of antiviral IFN-α and IFN-ω genes were observed. For example, three bat species appear to have lost all their IFN-α, while increasing the number of IFN-ω genes.
The most surprising finding, Schöben said, was the observed loss of IFN-α and the addition of an additional IFN-ω gene, which had “never been reported before.” The results suggest that new IFN-ω and missing IFN-α genes are important for resisting viral infections in bats while preventing excessive inflammatory responses. This feature is one that makes inflammation a double-edged sword in humans.
But while the discovery brings geneticists one step closer to understanding how bats evolved their unique ability to resist cancer and viruses, it doesn’t paint a complete picture. The study focuses solely on the genetics of innate immunity, the immediate immune response to infected cells, it said. tony shantzHe is a professor at Colorado State University’s Center for Vector-Borne Infectious Diseases, but was not involved in the study. This does not include information about bats’ adaptive immunity, which consists of antibodies and T-cell responses that many mammals use to fight disease. “These two are very different, but complementary elements of immunity,” Schontz explains. “To date, almost all the focus on bat immunity has been on innate immunity, primarily because studying adaptive immunity requires living animals, which few groups have, and it is much more complex. That’s why.”
Even without complete information, understanding changes in bats’ innate immune systems could help scientists develop gene therapies in humans that reduce susceptibility to certain diseases. We can also learn which genes determine the bat’s 20-30 year lifespan, and how the bat’s body has adapted to its environment. Process sugar-rich foods without causing the adverse effects seen in diabetics.
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And while bats are notorious for their role in spreading coronavirus, Professor Scheben said these new discoveries could help explain how bats can host powerful viruses and parasites without becoming seriously ill. We hope that this will point researchers in the right direction in understanding how to do this. One day, he says, this information could be used to prevent our species from suffering serious symptoms when infected. “It is not misplaced to believe that bat research could help prevent new pandemics.”
