One of the major hurdles for patients requiring blood transfusion is the unavailability of their blood type in a blood bank – an issue that researchers at University of British Columbia say they may be able to resolve through their latest research that involves snipping off antigens from Type A and Type B blood.
Chemists and scientists at UBC’s Centre for Blood Research have created an enzyme that is capable of snipping away the antigens found in Type A and Type B blood, making it more like Type O. With Type O blood being a universal donor, patients requiring immediate supply of blood can be given this antigen-stripped blood.
Researchers employed a new technology dubbed directed evolution to create this high-powered enzyme capable of snipping off antigens. The technology involves inserting mutations into the gene that codes for the enzyme, and selecting mutants that are more effective at cutting the antigens. In just five generations, the enzyme became 170 times more effective.
With this enzyme, UBC associate professor Jayachandran Kizhakkedathu and colleagues in the Centre for Blood Research were able to remove the wide majority of the antigens in Type A and B blood. But before it can be used in clinical settings, the enzyme used would need to remove all of the antigens. The immune system is highly sensitive to blood groups and even small amounts of residual antigens could trigger an immune response.
“We produced a mutant enzyme that is very efficient at cutting off the sugars in A and B blood, and is much more proficient at removing the subtypes of the A-antigen that the parent enzyme struggles with,” said David Kwan, the lead author of the study and a postdoctoral fellow in the Department of Chemistry.
“The concept is not new but until now we needed so much of the enzyme to make it work that it was impractical,” says Steve Withers, a professor in the Department of Chemistry. “Now I’m confident that we can take this a whole lot further.”
The study was published in the Journal of the American Chemical Society and was supported by the Canadian Institutes of Health Research and Canadian Blood Services.
