Bats’ immune systems have mechanisms to control inflammation, a mainstay of disease and ageing
Bats can live long and tolerate several viruses and pathogens because they have mechanisms in their immune systems to reign in inflammation, a mainstay of disease and ageing, according to a recent study.
The flying mammals have been linked to the emergence of the novel coronavirus (SARS-CoV-2) that causes the COVID-19. The creatures are also known to be hosts for several other viruses — including rabies and the Ebola virus — that effect humans.
The study — published in journal Cell Metabolism July 7, 2020 by researchers of the University of Rochester — shows how the mechanisms in bats can hold clues in developing new treatments for diseases in humans.
The researchers found bats to be unaffected by the SARS-CoV-2 virus, even though it is believed that they are the carriers of the virus. Another factor that puzzled them was that bats are small creatures: The smaller the living being is, the shorter its lifespan becomes. Bats, however, live for 30-40 years.
“We’ve been interested in longevity and disease resistance in bats for a while,” said Vera Gorbunova, a co-author of the study.
Studies have earlier been conducted on both, bats’ immune response and longevity. The two phenomena were, however, never combined and studied before, according to Andrei Seluanov, another co-author.
Both authors have studied longevity and disease resistance before, with one common theme cropping up in their research: Inflammation. This does not just speed up ageing, but is also is a factor in age-related diseases, including cancer, Alzheimer’s and cardiovascular diseases.
“With COVID-19, inflammation goes haywire. It may be the inflammatory response that is killing the patient, more so than the virus itself,” said Gorbunova.
The human body, to fight this inflammation, often detrimentally overreacts to such threats, something that evolution of more than a thousand years has helped bats overcome.
Their immune response controls viruses and simultaneously, does not mount a strong inflammatory response. Two factors have been responsible for this: Bats’ ability to fly and their living together in dense colonies.
Flying helps bats adapt to rapid body temperature increases, surges in metabolism and molecular damage, factors that may assist in disease resistance.
Living in dense colonies also creates ideal conditions for transmitting viruses and other pathogens. This perpetuates, what the authors call, an “arms race” between the immune systems of the bats and pathogens.
“Bats are always flying out and bringing back something new to the cave or nest and they transfer the virus because they live in such close proximity to each other,” said Seluanov.
“Usually the strongest driver of new traits in evolution is an arms race with pathogens,” said Gorbunova.
While humans have created conditions where they live in dense habitats, they have not yet evolved the sophisticated mechanisms of bats in combating viruses.
“Humans have two possible strategies if we want to prevent inflammation, live longer, and avoid the deadly effects of diseases like COVID-19,” said Gorbunova.
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