Stem cells for transplant can be harvested from blood, bone marrow or umbilical cord blood, but a new lab process could enable them to be grown in the lab from any donor cell. — dpa
Scientists have grown blood stem cells in the laboratory for the first time in a move that could potentially end the need for stem cell transplants.
During a stem cell (or bone marrow) transplant, damaged blood cells are replaced with healthy ones and can be used to treat conditions such as leukaemia.
However, finding a donor match can be difficult and some patients die before a donor is found.
In the new study, experts at the Murdoch Children’s Research Institute (MCRI) in Melbourne, Australia, have managed to grow stem cells in the lab and then show their successful use in mice.
The team believe that, with government funding, they could conduct a trial in humans in around five years’ time.
Professor Dr Elizabeth Ng, who led the research published in the journal Nature Biotechnology, said the researchers had overcome a major hurdle in producing blood stem cells.
“The ability to take any cell from a patient, reprogramme it into a stem cell and then turn these into specifically-matched blood cells for transplantation will have a massive impact on vulnerable patients’ lives.
“Prior to this study, developing human blood stem cells in the lab that were capable of being transplanted into an animal model of bone marrow failure to make healthy blood cells had not been achievable.
“We have developed a workflow that has created transplantable blood stem cells.
“Importantly, these human cells can be created at the scale and purity required for clinical use.” she said.
In the study, mice were injected with lab-engineered human blood stem cells.
Scientists found that the blood stem cells became functional bone marrow at similar levels to those seen in umbilical cord blood cell transplants.
Umbilical cord stem cell transplants are already offered to some sick patients if a donor cannot be found or a close relative is not a match.
In the new research, the team also found that the lab-grown stem cells could be frozen before being successfully transplanted into mice.
This mimicked how blood stem cells are preserved before being transplanted into patients.
A promising development
In the human body, stem cells are produced by bone marrow and can turn into different types of blood cells.
They mainly become red blood cells, which carry oxygen around the body; white blood cells, which help fight infection; and platelets, which help stop bleeding.
At the moment, stem cells for transplant can be harvested from blood, bone marrow or umbilical cord blood.
MCRI Stem Cell Biology Theme deputy director Prof Dr Ed Stanley said the new findings could lead to better treatment for a range of blood disorders.
“Red blood cells are vital for oxygen transport and white blood cells are our immune defence, while platelets cause clotting to stop us bleeding.
“By perfecting stem cell methods that mimic the development of the normal blood stem cells found in our bodies, we can understand and develop personalised treatments for a range of blood diseases, including leukaemias and bone marrow failure,” he said.
MCRI Blood Diseases Laboratory group leader Prof Dr Andrew Elefanty said not all patients at the moment find a donor match.
“Mismatched donor immune cells from the transplant can attack the recipient’s own tissues, leading to severe illness or death,” he explained.
“Developing personalised, patient-specific blood stem cells will prevent these complications, address donor shortages, and alongside genome editing, help correct underlying causes of blood diseases.”
Leukaemia UK Policy and Advocacy head Dr Georgia Papacleovoulou said: “Whilst still being rare, affecting around 650 children a year in the United Kingdom, childhood leukaemia is the most common cancer type amongst those under the age of 15.
“The survival rates are much higher than for other leukaemia types affecting adults, but the treatments are incredibly harsh.
“They rob children of their precious childhoods and can impact their mental, intellectual and physical development.
“This new research, which could lead to personalised treatments for childhood leukaemia, marks a promising breakthrough for treating this disease.
“It has the potential to reduce the risks which currently exist around stem cell transplants, such as cell rejection, which is a serious complication in current leukaemia treatments, and could give families much-needed hope of successful transplants.
“The crucial next step will be clinical trials to ensure the process is safe and effective.”
UK stem cell charity Anthony Nolan medical officer Dr Tania Dexter said: “This research has huge promise and could pave the way for transplants that do not rely on cells from a donor.
“However, it’s important to recognise this is early-stage research that’s a long way from being applied to patients.
“In the meantime, every single person who registers as a potential donor could be the match a person desperately needs right now.” – By Jane Kirby/PA Media/dpa
