Recently, Chinese and American scientists have made important progress in the field of Middle East Respiratory Syndrome (MERS) virus research. They discovered for the first time the way the virus spreads from bats to humans, and the relevant results were published in the Proceedings of the National Academy of Sciences.
Scientists already know the two steps of the MERS virus infecting human cells: first, the receptor molecule DPP4 adsorbed on the surface of human cells, and then enters the human cells. However, it is not yet clear how the MERS virus has evolved the ability to infect human cells across species. The research team used a HKU4 coronavirus (the "close relative" of the MERS virus in bats) found in East Asian bats that has never infected humans to conduct comparative experiments with the MERS virus.
The experimental results show that the two viruses recognize the same receptor molecule DPP4, but the MERS virus can more effectively recognize the human DPP4 molecule, while the HKU4 virus is the opposite. In addition, both viruses can enter bat cells, but after the HKU4 virus adsorbs to the DPP4 molecules on the surface of human cells, it does not have the ability to enter human cells, while the MERS virus can easily enter human cells.
The results of this study prove that the MERS virus has adapted to human cells through mutation and evolution and can smoothly infect humans, while the HKU4 virus does not yet have the ability to infect human cells. This discovery helps to understand the animal origin of the MERS virus and provides a reference for blocking, preventing and controlling the spread of the virus between humans.
The work was led by Li Fang, a tenured associate professor at the University of Minnesota, and was completed in collaboration with scientists such as Fudan University expert Jiang Shibo, New York Blood Center associate researcher Du Lanying, and University of North Carolina professor Ralph Baric.
It is understood that the "Middle East Coronavirus" was first discovered in the Middle East in 2012 and currently infects 837 people worldwide, with a fatality rate of 35%, which is much higher than the "SARS virus" that swept Southeast Asia in 2003 with a fatality rate of 10%. (These two viruses belong to the coronavirus family). As the Ebola virus in Africa is raging again, experts reminded that the end of the SARS epidemic does not mean the extinction of the highly pathogenic coronavirus.