Researchers find way to trigger red blood cells on demand

Researchers at the University of Virginia School of Medicine have discovered an unexpected new way to trigger the production of red blood cells.

The discovery could represent a significant step forward in the battle against anaemia, benefitting people with diabetes, people with kidney disease or cancer, and older people for whom anaemia can become a chronic problem. 

The new approach could also allow doctors to turn on red blood cell production whenever necessary. It could also be used on the battlefield to triage wounded soldiers until they receive a blood transfusion.

The UVA researchers were not investigating anaemia when they made their discovery. Instead, Thomas J. Braciale, MD, PhD, and his team members were looking into the role of dendritic cells in the lungs. Dendritic cells have traditionally been thought to be sensors of infection and inflammation, but a lab test involving the flu virus produced a bizarre effect in mice that ultimately revealed an entirely new aspect to the cells’ function. 

After injecting mice with the flu virus and an antibody that blocked a certain molecule expressed by dendritic cells, the researchers discovered that the experiment had an unexpected effect: The mice’s spleens enlarged massively. The researchers were baffled, so they repeated the experiment, only to get the same results.

“Giant spleens”

“We did it again and I didn’t believe it, and we did it again and I didn’t believe it,” Braciale recalled. “I asked whether you needed to flu infect the mice when you injected this antibody. So the postdoc [a lab member] did the experiment, and he just injected the antibody without flu injecting the mice. Giant spleens. After much consultation, after talking with my colleagues in Pathology, we decided we were inducing stress erythropoiesis.”

Stress erythropoiesis is when the body produces red blood cells because of injury or other stress. In discovering an unexpected molecular trigger for the process, Braciale had found a switch he could flip to prompt red blood cell production.

“In the very basic way, what we’ve discovered is that the process of regulating stress in the body is mediated – certainly in part, at least – by these dendritic cells,” he explained. “And stress can be a variety of different stresses. It doesn’t have to be infection, it doesn’t have to be inflammation. It can be anaemia. It can be haemorrhage. And these cells act to initiate this response that, until this report, there’s been really no evidence that these [dendritic] cells ever participate in making red blood cells.”

Braciale has more work to do before researchers can begin testing the approach in people. However, he’s optimistic, based on his findings so far. “We’re very excited to see where this goes.”