Australian researchers have discovered another pathway the COVID-19 virus uses to get into human cells, which may explain the high infection rate of the virus, when compared to other similar viruses.
It was already known to researchers that the SARS-CoV-II virus, which causes COVID-19 symptoms, uses ACE2 receptor on human cells as a doorway to get in by binding its spike protein to the receptor.
In two studies released on Wednesday, researchers from the University of Queensland (UQ) in Australia and their colleagues in Europe found out that the virus can also use another receptor, called neuropilin to enter human cells.
Prof. Brett Collins, a co-researcher from UQ’s Institute for Molecular Bioscience, said: “We now know that in addition to the already known ACE2 receptor, the spike binds to a second receptor on the host cells called neuropilin.
“We used X-ray crystallography to see the structure of proteins at the atomic level and visualise the binding sites at a spectacular level of detail.’’
According to Collins, the fact that antibodies blocking the neuropilin receptor NRP1 are able to block infection by 40 per cent strongly suggested that this pathway is key for the virus’ infectivity.
Another co-researcher, Prof. Frederic Meunier from UQ’s Queensland Brain Institute, said that NRP1 was found in a variety of human cells, which could explain why SARS-CoV-II virus could also affect human brain cells, while the long-term consequences were not yet known.
“The discovery that NRP1 binds to Spike opens the door to in-depth research into the virus’ neurotropism, its ability to infect nerve tissue, as well as new therapeutic avenues,” he said.