Coronavirus Research: Another new, yet to be peer-reviewed study by Chinese researchers from the National Translational Science Center for Molecular Medicine & Department of Cell Biology, Fourth Military Medical University, Xi’an, China lead Professor Dr Ke Wang, a leading virologist and genomic researcher and a team of 29 other researchers from 4 other medical and research institutions have discovered a fourth route by which the new SARS-CoV-2 coronavirus that causes the Covid-19 disease can attach and bind itself the human host cells. (https://www.biorxiv.org/content/10.1101/2020.03.14.988345v1.full.pdf+html)
Initial studies have showed that the SARs-CoV-2 attacks human host cells through the ACE-2 receptors, then furin targets and lately GRP78 receptors. (https://www.thailandmedical.news/news/breaking-latestcoronavirus-research-reveals-that-the-virus-has-mutated-gene-similar-to-hiv-and-is-1,000-times-more-potent-) and (https://www.thailandmedical.news/news/breaking-preprint-research-shows-that-sars-cov-2-has-third-binding-mode,-making-it-a-truly-potent-coronavirus-that-is-in-a-league-of-its-own)
The latest study shows that SARS-CoV-2can invade human host cells via a novel route of CD147-spike protein (SP). SP bound to CD147, a receptor on the host cells, thereby mediating the viral invasion.
Past studies have shown that CoVs are non-segmented positive sense RNA viruses, which primarily cause enzootic infections typically in birds and mammals and have demonstrated strong lethality in humans.
These coronaviruses are known to have four structural proteins, including E, M, N and S protein. The primary determinant of CoVs tropism is the S protein, which binds to the membrane receptor on the host cells, mediating the viral and cellular membrane fusion.
Angiotensin-converting enzyme 2 (ACE2), a homologue of ACE, is one of the important receptors on the cell membrane of the host cells. The interaction of SP and ACE2 contributes to the SARS-CoV invasion for human host cells.
Interestingly, the structure of SARS-CoV-2 SP is highly similar to that of SARS-CoV SP, and SARS-CoV-2 SP binds to ACE2 with a higher affinity than SARS-CoV SP, indicative of a stronger ability of SAR-CoV-2 to invade host cell.
In addition to ACE2, other receptors for SP binding on the host cell membrane includes furin and also GRP78 receptors.
CD147, also known as Basigin or EMMPRIN, is a transmembrane glycoprotein that belongs to the immunoglobulin superfamily, which is involved in tumor development, plasmodium invasion and virus infection.
Past researches show that CD147 plays a functional role in facilitating SARS-CoV invasion for host cells, and CD147-antagonistic peptide-9 has a high binding rate to HEK293 cells and an inhibitory effect on SARS-CoV. These researches affirm the importance of CD147 in virus invasion for host cells.
As a result of the similar characteristics of SARS-CoV and SARS-CoV-2, the researchers decided to conduct the new study to investigate the possible function of CD147 in invasion for host cells by SARS-CoV-2.
Their study confirmed that the SARS-CoV-2 invaded host cells via a novel route of CD147-SP….