- The virus binds with heparin carbohydrate molecule to enter lung cells
- Researchers to study how carbohydrate molecule can help prevent infections
- Heparin treatment works as anti-viral: Researchers
Los Angeles: Scientists have identified a key carbohydrate molecule, called heparan sulphate, which the novel coronavirus uses to infect human cells, an advance that may provide a potential new approach for preventing and treating COVID-19. The molecule ACE2 sits like a doorknob on the outer surfaces of the cells that line the lungs, and researchers know that SARS-CoV-2 virus primarily uses it to enter these cells and establish respiratory infections. The study, published in the journal Cell, found that SARS-CoV-2 can’t grab onto ACE2 without heparan sulphate, which is also found on lung cell surfaces and acts as a co-receptor for viral entry.
Also Read: Coronavirus Vaccine Updates: What Is A Human Challenge Trial And Can It Speed Up COVID-19 Vaccine Development?
“ACE2 is only part of the story. It isn’t the whole picture,” said Jeffrey Esko, a professor at the University of California San Diego School of Medicine in the US. The team demonstrated two approaches that can reduce the ability of SARS-CoV-2 to infect human cells cultured in the lab by approximately 80 to 90 per cent. The first approach works by removing heparan sulphate with enzymes, and the second uses heparin as bait to lure and bind the coronavirus away from human cells, according to the researchers.
Heparin, a form of heparan sulphate, is already a widely used medication to prevent and treat blood clots, suggesting that an approved drug might be repurposed to reduce virus infection, they said. The team uncovered the exact part of the SARS-CoV-2 spike protein that interacts with heparin — the receptor binding domain.
The researchers found that when heparin is bound, the receptor binding domain opens up and increases binding to ACE2. The virus must bind both heparan sulphate on the cell surface and ACE2 in order to get inside human lung cells grown in a laboratory dish, they said. With this viral entry mechanism established, the researchers next set about trying to disrupt it. They found that enzymes that remove heparin sulphate from cell surfaces prevent SARS-CoV-2 from gaining entry into cells. Similarly, treatment with heparin also blocked infection, according to the researchers. The heparin treatment worked as an anti-viral at doses currently given to patients, even when the researchers removed the anticoagulant region of the protein — the part responsible for preventing blood clots, they said.
Also Read: ‘Excellent Safety’ Of Two Indigenous COVID Candidate Vaccines Revealed During Phase-I Trials: Minister
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
NDTV – Dettol Banega Swasth India campaign is an extension of the five-year-old Banega Swachh India initiative helmed by Campaign Ambassador Amitabh Bachchan. It aims to spread awareness about critical health issues facing the country. In wake of the current COVID-19 pandemic, the need for WASH (Water, Sanitation and Hygiene) is reaffirmed as handwashing is one of the ways to prevent Coronavirus infection and other diseases. The campaign highlights the importance of nutrition and healthcare for women and children to prevent maternal and child mortality, fight malnutrition, stunting, wasting, anaemia and disease prevention through vaccines. Importance of programmes like Public Distribution System (PDS), Mid-day Meal Scheme, POSHAN Abhiyan and the role of Aganwadis and ASHA workers are also covered. Only a Swachh or clean India where toilets are used and open defecation free (ODF) status achieved as part of the Swachh Bharat Abhiyan launched by Prime Minister Narendra Modi in 2014, can eradicate diseases like diahorrea and become a Swasth or healthy India. The campaign will continue to cover issues like air pollution, waste management, plastic ban, manual scavenging and sanitation workers and menstrual hygiene.