Melbourne researchers have achieved a world first: they have successfully created blood stem cells that closely resemble human tissue. Additionally, the discovery could eventually result in customized treatments for children suffering from bone marrow failure syndrome and leukemia.
The study, led by the Murdoch Children’s Research Institute (MCRI) and published in Nature Biotechnology, has successfully overcome a key hurdle in producing human blood stem cells that are capable of generating red, white and platelet cells similar to those found in human embryos.
MCRI Associate Professor Elizabeth Ng said the team has made a breakthrough in the development of human blood stem cells, paving the way for the use of these lab-grown cells in blood stem cell and bone marrow transplants.
“The ability to take any cell from a patient, reprogram them into stem cells, and then turn them into specifically matched blood cells for transplantation would have a huge impact on the lives of these vulnerable patients,” he said.
“Prior to this study, it was not possible to grow human blood stem cells in the laboratory that could be transplanted into animal models with bone marrow failure to make healthy blood cells. We developed a workflow that produced transplantable blood stem cells that closely resembled the cells found in human embryos.
“Importantly, these human cells can be produced at the scale and purity needed for clinical use.”
In the study, immune-deficient mice were injected with lab-grown human blood stem cells. It was found that the blood stem cells became functional bone marrow at levels similar to those seen in cord blood cell transplants, a proven benchmark of success.
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The research also found that lab-grown stem cells could be frozen before being successfully transplanted into mice. This mimics the preservation process of donor blood stem cells before they are transplanted into patients.
MCRI Professor Ed Stanley said these findings could lead to new treatment options for a variety of blood disorders.
He added, “Red blood cells are important for oxygen transport and white blood cells are our immune defence, while platelets form clots to stop bleeding.” Understanding how these cells develop and work is like solving a complex puzzle.
“By perfecting stem cell methods that mimic the development of normal blood stem cells found in our bodies we can understand and develop personalized treatments for a variety of blood diseases, including leukemia and bone marrow failure.”
MCRI Professor Andrew Elefanti said although blood stem cell transplantation is often a vital part of life-saving treatment for childhood blood disorders, not all children can find an ideal donor.
“Mismatched immune cells from a transplant donor may attack the recipient’s own tissues, leading to serious illness or death,” he said.
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“The development of personalised, patient-specific blood stem cells will prevent these complications, address donor shortages and, together with genome editing, help treat the underlying causes of blood diseases.”
Professor Elefanti said the next step, possibly in about five years with government funding, would be a phase I clinical trial to test the safety of using these lab-grown blood cells in humans.
At the age of 11, Riya was diagnosed with aplastic anemia, a rare and serious blood disorder in which the body stops producing enough new blood cells.
Riya’s family, including her parents Sonali and Gaurav Mahajan, were in India when she began feeling tired, lost weight rapidly, and developed bruises on her thighs.
Sonali said, “We took Riya for a simple blood test, which was her first test. But as soon as the results came, we were asked to take her to the emergency department, as her platelets and red blood cell levels were very low.”
“Riya was initially diagnosed as having leukaemia as its symptoms were very similar to aplastic anaemia. When we got the final diagnosis, it was a complete shock and a condition we had never heard of before.
“The doctors told us that his bone marrow had malfunctioned and he would need regular platelet and blood transfusions to boost his blood cell count.”
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Sonali said the family had already planned to return to Australia for Riya’s high school education but had to postpone the return plan after the illness was detected.
“Once they managed to stabilise him, we were given two days to fly him to Australia for hospitalisation,” he said.
“As soon as we got off the plane, we went straight to the Royal Children’s Hospital. Within a few days, Riya started therapy, but the medicines did not have much effect on her.
“Ultimately a bone marrow transplant was recommended, as he required so many blood transfusions and there was a risk of long-term complications.”
Sonali said that for more than six months they could not find a donor who was a perfect match and they had lost hope. Despite being a half match, Sonali became her daughter’s donor on the advice of a specialist.
Rhea was in hospital for three months following a bone marrow transplant in June last year, where she suffered minor complications.
Without a perfect donor match, Riya’s platelet count took longer to return to normal, she required longer immunosuppressive therapy and she was more susceptible to infections. Riya has recently started getting vaccinated again.
“His immune system remained weak for a long time after the transplant, but thankfully, he did not need a second transplant after he was discharged from the hospital,” Sonali said.
Ria, 14, said after a traumatic few years she was now feeling better, had taken hydrotherapy classes and was happy to be back at school with her friends.
Sonali said that the new research led by MCRI on blood stem cells is a remarkable achievement.
“This research will prove to be a boon for many families,” he said. “The fact that targeted treatments will one day be available for children suffering from leukemia and bone marrow failure disorders is life-changing.” (ANI)
