For several decades researchers have been working to find an effective way to convert one blood type into another. Type O blood, often considered the universal blood type, is most useful in emergency situations, and new research presented at the National Meeting & Exposition of the American Chemical Society has revealed that an enzyme produced by gut bacteria could be the key to safely and easily turning type A and B blood into type O.
One of the defining characteristics of type A or type B blood is the presence of sugar molecules on the surface of the cells. Called antigens, these molecules are one of the primary factors differentiating A or B blood with type O, a blood type that has no antigens on its cell surfaces. The big challenge is finding a compound that effectively removes these antigens from A or B blood, essentially turning it into the more universally useful type O.
"We have been particularly interested in enzymes that allow us to remove the A or B antigens from red blood cells," says Stephen Withers, one of the researchers on the project from the University of British Columbia (UBC). "If you can remove those antigens, which are just simple sugars, then you can convert A or B to O blood."
This idea, using enzymes to strip antigens from the surface of blood cells, has been the source of much study since as far back as the 1950s. A number of different enzymes have been targeted in experiments over the years, but nothing has been found that has proven to be comprehensively effective, safe and economical.
Back in 2015, a team from the University of British Columbia revealed one of the most promising developments in the field to date, creating a mutant enzyme that was selectively evolved to be more effective at attacking the target antigens. Now, Withers and colleagues at UBC have homed in on a potentially more effective enzyme that is produced by the human gut microbiome.
The team set out to sample the genes of millions of microorganisms, searching for genes coded to produce specific enzymes that target sugar residues. The search focused in on enzymes produced by gut bacteria that were known to feed on sugars that are similar in structure to the antigens on A- and B-type blood cells. A new family of enzymes was discovered that the researchers claim is 30 times more effective at clearing antigens off blood cells than any other enzymes they have previously studied.
"I am optimistic that we have a very interesting candidate to adjust donated blood to a common type," explains Withers. "Of course, it will have to go through lots of clinical trails to make sure that it doesn't have any adverse consequences, but it is looking very promising."
The work is yet to be officially published in a peer-reviewed journal so it is hard to tell whether this is the big enzyme breakthrough researchers in the field have been working toward for the past 50 years. However, the implications of the research, if proven effective, are incredibly significant. It would effectively mean that a simple enzyme preparation could be added to type A or B blood bags to turn the contents into a more universal type O, allowing for rapid emergency blood supplies to be deployed in major emergency scenarios.
The new research is presented this week at the 256th National Meeting & Exposition of the American Chemical Society (ACS).
The development is outlined in the video below.
Source: American Chemical Society
