Live imaging allows researchers to see how stem cells find their niche in bone marrow

08 October 2015

Francis Crick Institute researchers have used live imaging to track human blood stem cells in the bone marrow as they seek out their preferred environment, or niche.

The team hopes that learning more about blood stem cells - called haematopoetic stem cells or HSCs - and the HSC niche will evenutally help them understand leukaemia stem cells and their niche, and potentially lead to new ways to treat the cancer.

The research was led by Dr Dominique Bonnet at the Crick. She explained: "The niche is an important regulator of HSC fate. This means that understanding where in the bone marrow HSCs go and their niche will give us information about which cells and which molecules secreted by different tissues play a role in regulating HSCs.

"Scientists have made advances in understanding interactions between mouse HSCs and their niche but, until now, little was known about communication between human HSCs and their immediate environment."

Dr Bonnet's team used a technique called intravital imaging to track human HSCs translanted into mice that have deficient immune systems - meaning they wouldn't react against the human HSCs.

The results showed that after transplanation the human HSC cells entered the bone marrow of the mice and kept moving in search of the right environnment. When they found it they suddenly stopped - in contrast to more developed types of cells, which do not stop.

Dr Bonnet said: "Our paper proposes that, to better define the HSC niche, we should look at the movement of HSCs and define their niche environment when they stop moving. Intravital imaging is the only technique that can determine where in the bone marrow HSCs stop moving and therefore where that niche is.

"In the future, we hope to use a similar imaging technique to  define the leukaemia stem cell niche. We don't know whether this is the same as the normal HSC niche, and whether the two types of stem cell compete for the same niche. Understanding this could help us understand the external factors that maintain leukaemia stem cells and thus help us develop new strategies to eradicate them."

The paper, Different Motile Behaviors of Human Hematopoietic Stem versus Progenitor Cells at the Osteoblastic Niche, is published in Stem Cell Reports.

  • Live imaging has allowed scientists at the Francis Crick Institute to track human blood stem cells in the bone marrow as they seek out their preferred environment, or niche.
  • Stem cells are immature cells that have not yet developed into the specialised cells that make up our organs and tissues. They also have the ability to 'self-renew', or make identical copies of themselves, almost indefinitely. Haematopoetic stem cells (HSCs) are found in the bone marrow and generate all the different types of mature blood cells.
  • The research was supported by Cancer Research UK.