In a paper published on the 19th in Nature Microbiology, researchers have identified a set of enzymes in the gut-dwelling mucin-loving bacterium Akkermansia muciniphila that can convert known and previously unknown antigens in human red blood cells, transforming blood into type O. This discovery may offer clinical solutions and enhance the supply of universally compatible blood.
The research diagram illustrates the A, B, and O blood group antigens on red blood cells and mucin proteins.
Image Source: "Nature Microbiology"
When people refer to blood types, they are talking about the specific antigens on the red blood cell membrane, which are closely related to clinical aspects. There are various human blood types, determined by the "identity cards" of the cells – the sugar chains covering their surfaces. Specifically, red blood cells have sugar chains called polysaccharides on their surfaces, which vary among individuals. These different forms present as the familiar A, B, and O blood types.
Blood type matching is crucial during transfusions because the immune system can react to mismatched blood cells, potentially leading to fatal reactions. Type O blood is universally compatible as its sugar structure is shared by all blood types. Sometimes hospitals face shortages of type O blood reserves, necessitating strategies to convert type A and B blood to type O.
In this study, researchers from the Technical University of Denmark and Lund University in Sweden conducted biochemical screening of enzymes produced by the mucin bacterium Akkermansia, which can break down polysaccharides in mucus. They identified a unique set of enzymes that effectively convert type A and B red blood cells to type O. This enzyme combination also works on the recently discovered expanded types of A and B, reducing mismatch reactions in tests, especially for converted type B.
The research team believes their discovery could serve as a potential tool for handling red blood cells, increasing reserves of universally compatible blood to alleviate emergency transfusion issues. However, further work is needed to improve the conversion of type A blood.
