Human blood comes in four major "types" — A, B, AB and O — which differ in the sugars on their red blood cells (RBCs). Correctly matching blood types before transfusions is essential to avoid immune responses that can be fatal. O type blood is known as a universal donor since RBCs from an O type person can be transfused into A, B, AB or O type individuals without harm. It is used in emergencies when there is no time to type the patient or the correct type is unavailable. Type O blood is often in short supply.
A and B type blood can be converted to universal O type blood by using specific enzymes to clip off the extra sugars: once clipped the original sugars are not reformed since mature RBCs have lost that ability. However the enzymes available have not been efficient enough. The Withers lab recently discovered efficient enzymes for this within the human gut microbiome. In conjunction with the Centre for Blood Research, they have proven their efficiency and converted whole units of blood. This proposal is primarily to carry out the pre-clinical evaluations needed, and in conjunction with Canadian Blood Services, move this technology forward. This will open up access to universal donor blood, thereby helping alleviate shortages.