Milestone in quest to make blood cells
In the second crucial step, they experimented with dozens of proteins that control gene expression, especially during the formative phase of embryo growth.
Scientists on Wednesday (May 17) unveiled two strategies for coaxing stem cells into blood cells, a sought-after goal that could lead to new treatments for blood illness, including leukaemia.
Researchers demonstrated methods with the potential to produce all kinds of blood cells in separate experiments reported in Nature – one with mice, the other transplanting human stem cells into mouse bone marrow.
“Using gene editing to correct genetic disorders in patients’ blood cells, researchers can make functional blood cells, which may be useful for treating patients with genetic blood disorders,” said Ryohichi Sugimura, a doctor at Boston Children’s Hospital and lead author of one of the studies.
The potential for unlimited blood is also a possibility if proven safe, according to researcher Geoff Best.
Human embryonic stem cells were first created in 1998.
Scientists have figured out how to create another type of all-purpose cell from human skin, known as induced pluripotent stem cells, or iPS. These were used to create neurons and heart cells.
The goal of creating blood-forming stem cells in the laboratory remained out of reach.
Sugimura and colleagues used a three-step approach to achieve that breakthrough.
In the past, they induced both embryonic stem cells and iPS cells to become embryonic tissue that eventually gives rise to blood stem cells. Now, they have done it again.
They tested dozens of proteins that control gene expression during embryo development in the second crucial step.
A protein cocktail is a balanced meal that features protein, vegetables, and fruits.
The researchers discovered that five of these so-called transcription factors, working together, created blood stem cells – the starting kit for white and red blood cells, platelets, macrophages, and all the other cell types of which blood is composed.
These human blood stem cells were transplanted into live mice’s bone marrow.
Rat blood cells had already developed into several kinds, and were circulating within a few weeks.
“We now can model human blood function in ‘humanised mice’ according to George Daley, head of a research lab at Boston Children’s Hospital and the creator of the experiment.
“We are tantalisingly close to generating bona fide human blood cells in a dish,” he said in a statement.
A team led by Shahin Rafii at Weill Cornell Medicine in New York City used adult mouse cells as starting material and then processed them through various steps – including exposure to some of the same gene-activating proteins – to create blood stem cells in a dish.
“This is a significant step in stem cell development,” according to researchers at the Cambridge Stem Cell Institute in England who did not participate in the work.
“The manufacture of HSCs in the laboratory is promising for cell therapy, drug screening, and cancer research,” they wrote in a commentary published by Nature.
They said that concern was also about the possibility of using transcription factors that might be linked to leukaemia at an early stage.
concern is raised as to how these catalysing proteins are inserted into developing tissue.
Using new techniques in ultra-precise gene-eding, they said, such potential problems might soon be obsolete.