Discovery of Rare Blood Stem Cell May Yield New Insights

Scientists have identified stem cells that can regenerate all types of cells in the blood system. (Image: Timothey Kosachev/

Scientists have been able to isolate a rare type of stem cell that can regenerate all the types of cells in the blood system, according to a new study in Science. The finding may help the development of new clinical applications for stem cells and may aid further stem cell research.

Stem cells are a source of new blood cells throughout an individual’s life span, but they are rare and hard to separate from other cell types, making them a challenge to study. But a multi-institution team of scientists from Canada, using flow cytometry techniques, isolated various subsets of cells to identify those with the most regenerative capability. They found that human stem cells that can generate multiple different types of cells and regenerate themselves over the long term express the adhesion molecule CD49F on their surface—a trait that distinguishes these cells from multipotent progenitor cells that can give rise to multiple cell types but only have transient regenerative capacity.

To test the regenerative potential of the cells, the researchers isolated single human stem cells based on expression of CD49f as well as 2 other markers of human stem cells and transplanted them into mice, where they did in fact give rise to multiple types of cell lines.

The authors conclude the ability to isolate such distinct populations of human stem cells should help scientists to tease out the specific programming the cells require to produce various cell lines.

“This discovery means we now have an increasingly detailed road map of the human blood development system, including the much sought-after stem cell,” said principle investigator John Dick, senior scientist at the McEwen Centre for Regenerative Medicine and the Ontario Cancer Institute, Canada, in a statement.

Categories: Evidence-Based Medicine, Hematology/Hematologic Malignancies