UK researchers have discovered natural molecules that can help the coronavirus (SARS-CoV-2) to hide from certain antibodies, explaining why some people some patients become severely ill even after having high levels of antibodies against the deadly virus.
The researchers from Francis Crick Institute, Imperial College London, Kings College London, and UCL (University College London), who published their research on Thursday in Science Advances, found that the natural molecules – biliverdin and bilirubin – could suppress the binding of antibodies to the coronavirus spike, according to Medical Xpress.
The team discovered that the COVID-19 virus spike protein strongly binds to biliverdin, a molecule that was giving these proteins an unusual green coloration, eventually concluding that it reduced antibody binding to the spike.
The scientists found that biliverdin suppressed the binding of human antibodies to the spike by 30 to 50%, with some antibodies becoming ineffective at neutralizing the virus, per Medical Xpress.
Annachiara Rosa, the first author of the study, said, “When SARS-CoV-2 infects a patient’s lungs it damages blood vessels and causes a rise in the number of immune cells. Both of these effects may contribute to increasing the levels of biliverdin and bilirubin in the surrounding tissues.”
“And with more of these molecules available, the virus has more opportunity to hide from certain antibodies,” Rosa explained. “This is a really striking process, as the virus may be benefiting from a side effect of the damage it has already caused.”
Peter Cherepanov, senior group leader at the Crick, said, “In the first months of the pandemic, we were extremely busy churning out viral antigens for SARS-CoV-2 tests. It was a race, as these tests were urgently needed.”
“When we finally found the time to study our green proteins, we expected a mundane answer,” he added. “Instead, we were astonished to discover a new trick the virus uses to avoid antibody recognition. This is a result of a collaborative effort of several amazing teams working at the Crick and three partner universities, led purely by scientific curiosity.” Further, the researchers are expected to work more on these findings by measuring the levels of biliverdin and other molecules in COVID-19 patients. They will also explore if it is possible to hijack the binding site used by biliverdin to potentially find new ways to target the virus, according to Medical Xpress.
