Findings from a group of Iowa State University researchers could lead to the ability to create new blood stem cells from a patient’s own blood, possibly doing away with the need for bone marrow transplants.
ISU assistant professor of genetics, development and cell biology Raquel Espin Palazon and her team discovered that a microbial sensor that aids in finding bacterial infections, known as Nod1, also plays a key role in the creation of blood stem cells.
Learning this information and finding where in the process it takes place will allow researchers to make strides in producing functional blood stem cells in vitro, which Espin Palazon said cannot currently be done.
“We cannot produce blood stem cells that are going to be able to be transplanted and cure diseases, cure leukemia and anemia,” Espin Palazon said. “So we’re really trying to find which switches to touch in those protocols in vitro to make those blood stem cells, and this Nod1 is a very important and critical switch.”
Before an embryo’s heart even begins to beat, some of the endothelial cells that are forming its vascular system are instead becoming blood stem cells. A lifetime’s worth of these will be created before birth. Espin Palazon said they found that the Nod1 microbial receptor needs to be activated before those endothelial cells transform into blood stem cells.
If Nod1 can be activated in immature stem cells taken from a patient, blood stem cells can then be created to treat them.
For some patients diagnosed with blood diseases and disorders, the only treatment available is a bone marrow or umbilical cord blood transplant. According to the Health Resources and Services Administration, about 18,000 people are diagnosed with life-threatening illnesses where these transplants are the only option.
Finding matching donors for these transplants can be very difficult, Espin Palazon said. Even if a match is found and the transplant is successful, the recipient has a more than 50% chance of developing graft-versus-host disease, where the body’s immune system identifies the new blood stem cells as foreign bodies, and attacks them, which can be deadly. Having the ability to create blood stem cells that wouldn’t risk being attacked as foreign entities would greatly lower the risks those impacted have to undertake when receiving a transplant.
“If we could generate patient-specific blood stem cells in the dish … then we don’t have to find donors and we wouldn’t have the graft-versus-host disease,” Espin Palazon said. “So that would cure a lot of people.”
With these findings, the researcher said there’s a good chance that she will get to see new blood stem cells created from patients within her lifetime, maybe even in the next 20 years.
Espin Palazon said her journey to these findings was serendipitous, as it was her interest in the immune system, not blood cell development, that led her here. The professor was working on her doctorate in Spain, her home country, in the late 2000s and studying the immune system when she found that embryos wouldn’t develop normally if inflammatory signals like Nod1 were removed.
Trying to find literature on the impact these factors have on embryonic development were unsuccessful, as scientists had largely not looked into the subject, and so she turned her research to this topic.
“It’s been basically my whole life as a researcher studying this field that was totally neglected before,” Espin Palazon said. “So being able to have this contribution to the scientific community and humanity with these important signals that are critical to make bloods themselves, it’s been just amazing.”