A team of researchers within the Advanced Glycoscience Research Cluster (AGRC) at NUI Galway have discovered how human respiratory cells respond to the invading COVID-19 virus.
The study, published in a special issue of the peer-reviewed open access journal Viruses, identified the proteins and carbohydrates on these cells in response to infection from the coronavirus.
Carbohydrates and proteins
The researchers found that our respiratory cells act like well-tuned translators and respond to the invading COVID-19 virus by altering the presence of carbohydrates and proteins on the cell’s surface.
The study also revealed that our response to COVID-19 infection is closely similar to how we respond to other viral pathogens.
Professor Lokesh Joshi, Stokes Professor of Glycosciences, said: “It is well known that all pathogens need the right combination of proteins and carbohydrates to attach to their host and infect.
“The appropriate combination of this ‘molecular handshake’ determines how well all pathogens, including COVID-19, attach to our cells and the severity of the infection.
Infectivity of mutants
“Mutations cause minor changes in these protein-carbohydrate molecules and can alter the infectivity of the mutants and severity of the disease such as the UK, South African and Brazilian variants.”
The research shows that in the COVID-19 virus the spike-glycoprotein (S-protein) is covered with carbohydrates and it binds to a protein (ACE-2 receptor) on human respiratory cells to start the infection.
Dr Anup Mammen Oommen, postdoctoral researcher, said: “These microscopic proteins and carbohydrates work together like molecular handshakes between the virus and human cells, this communication where carbohydrates are essential is often taken for granted, though is a key event for infection.”
Dr Stephen Cunningham, research fellow, added: “Like all viruses, the COVID-19 virus also mutates as it goes through its host and multiplies. Being a RNA virus, mutations can be frequent with the infected cell not being able to correct.
"Some mutations are insignificant with no beneficial or detrimental impact to virus or host, however, some lead to changes in the virus’s proteins and carbohydrates that can alter how the virus interacts with cells during exposure and infection which, in turn, can determine the severity of COVID-19.”
The AGRC researchers at NUI Galway used a data science approach to provide an insight into how our cells modify the surface molecules and advance our understanding of the COVID-19 infection process.
Professor Joshi added: “The research will also help us gain better insight on how our immune system responds to COVID-19 and the mutations in the virus, such as the variants identified in the UK, South Africa and Brazil. This discovery will lead to more informative biomarkers and identification of therapeutic targets to combat COVID-19 and future pathogenic agent infections.”
The study has been published in the special issue of the journal Viruses and is available https://www.mdpi.com/journal/viruses https://www.mdpi.com/1999-4915/13/1/82.