Bat immune system makes virus more deadly

In recent years, novel coronavirus pneumonia, SARS, MERS, Ebola, Marburg disease and new emerging pneumonia have all originated from bats Recently, a new study published by the Cara e brook team at the University of California, Berkeley, found that bats' strong immune response to the virus may promote the virus to replicate faster, so when the virus spreads to mammals (such as humans) with normal immune system, it will cause fatal damage Some bats - including those believed to be the source of human infection - have an immune system that is always ready to defend against the virus and quickly isolate it from the cells While this may protect bats from high viral loads, it may also promote faster reproduction of these viruses in the host This makes bats unique hosts for rapid propagation and highly transmitted viruses Although bats can tolerate these viruses, when the latter enters other animals without a rapid response immune system, it will quickly destroy the new host, resulting in a high mortality rate "Some bats can produce this powerful antiviral response, but it also balances the anti-inflammatory response," said Cara brook, a postdoctoral fellow at the University of California, Berkeley, who co authored the study If we try the same antiviral strategy, our immune system will produce a wide range of inflammation " Destroying bats' habitats seems to put pressure on them to release more viruses in saliva, urine and feces, infecting other animals, the researchers said "At the end of the day, bats can be very special in 'storing' viruses," said Mike boots, a disease ecologist at the school Many viruses come from bats, which are not random Bats are not closely related to us, so they do not carry many human viruses But this study shows how the bat's immune system overcomes toxicity " As the only mammal that can fly, bats increase their metabolic rate in flight, making them twice the size of rodents in running Intense physical activity and high metabolic rates often lead to higher tissue damage due to the accumulation of active molecules, mainly free radicals, the researchers said But in order to be able to fly, bats seem to have evolved a physiological mechanism to effectively remove these harmful molecules That may be why bats live longer Some bats can live for 40 years, while rodents of the same size can only live for two years This rapid inhibition of inflammation may have another benefit: inhibition of inflammation associated with antiviral immune response A key skill in many bats' immune systems is to instantly release a signaling molecule called interferon alpha, which tells other cells to "be ready to fight" before the virus invades Brook and boots created a simple bat immune system model to model their experiments on a computer Researchers note that many bat viruses are transmitted to humans through animal vectors SARS coronavirus is transmitted to humans through civet cats, mers virus through camels, Ebola virus through gorillas and chimpanzees, Nipah virus through pigs, Hendra virus through horses, and Marburg virus through African green monkeys However, these viruses are still highly toxic and lethal when they finally enter the human body Researchers are designing a more formal model of bat disease evolution to better understand the spread of the virus in other animals and humans "In order to be able to predict the emergence and spread of infection, it is important to understand the evolutionary trajectory of infection." Said brook