In 1961, Dr. James Till and the late Dr. Ernest McCulloch discovered transplantable blood stem cells, giving rise to stem cell science. The research allowed us to unlock the remarkable potential of stem cells, which are able to develop into many different cell types and, as a result, are extremely useful when it comes to fighting diseases. Till and McCulloch’s research also set the foundation for our knowledge on the blood development system. However, this foundation has recently been shaken, thanks to a discovery made by researchers from the Princess Margaret Cancer Centre, University Health Network (UHN).
Through a series of experiments, the team was able to resolve how different kinds of blood cells quickly form from the stem cell. Notably, they learned that cells do not form farther downstream, as has been traditionally thought, completely contradicting the 50-year-old dogma.
The research topples the now old view that the blood development system is stable once formed. Ultimately, the research shows that the blood system is two-tiered and changes between early human development and adulthood. This redefining discovery involved mapping the lineage potential of nearly 3,000 single cells from 33 different cell populations of stem and progenitor cells, which were obtained from human blood samples at various life stages.
The findings will lead to a better understanding of a wide variety of human blood disorders, which is vital for patients afflicted with diseases like anemia and leukemia. There are also promising implications for the advancement of regenerative medicine, which may allow us to manufacture mature cell types, such as platelets or red blood cells, via induced pluripotent stem cells. Currently, human donors are the sole source of platelets for transfusions needed by thousands of patients with cancer and other debilitating disorders.