Immune cells regulate blood stem cells

February 21, 2014
Blood stem cell cultures: Blood stem cells from colonies (cell clusters) in vitro consisting of different blood cells. Nine blood stem cell colonies are illustrated in the image, which have developed into differentiated cell types, particularly into white blood cells (leukocytes).Credit: Department of Clinical Research of the University of Bern, Tumor-Immunology research group

Researchers in Bern, Germany, have discovered that, during a viral infection, immune cells control the blood stem cells in the bone marrow and therefore also the body's own defences. The findings could allow for new forms of therapy, such as for bone marrow diseases like leukaemia.

During a viral infection, the body needs various defence mechanisms – amongst other things, a large number of white blood cells (leukocytes) must be produced in the within a short period of time. In the bone marrow, stem cells are responsible for this task: the blood stem cells. In addition to , blood stem cells also produce and platelets.

The blood stem cells are located in specialized niches in the bone marrow and are surrounded by specialized niche cells. During an infection, the blood stem cells must complete two tasks: they must first recognise that more blood cells have to be produced and, secondly, they must recognise what kind of.

Now, for the first time, researchers at the Department of Medical Oncology at the University of Bern and Bern University Hospital headed by Prof. Adrian Ochsenbein have investigated how the blood stem cells in the bone marrow are regulated by the immune system's so-called T during a viral infection. As this regulation mechanism mediated by the immune system also plays an important role in other diseases such as leukaemia, these findings could lead to novel therapeutic approaches. The study is being published in the peer-reviewed journal Cell Stem Cell today.

T Killer cells trigger defences

One function of T killer cells is to "patrol" in the blood and remove pathogen-infected cells. However, they also interact with the blood stem cells in the bone marrow. The oncologists in Bern were able to show that messenger substances secreted by the T killer cells modulate the niche cells. In turn, the niche cells control the production and also the differentiation of the blood stem cells.

This mechanism is important in order to fight pathogens such as viruses or bacteria. However, various forms of the bone marrow disease leukaemia are caused by a malignant transformation of exactly these blood stem cells. This leads to the formation of so-called leukaemia stem cells. In both cases, the mechanisms are similar: the "good" mechanism regulates healthy during an infection, whilst the "bad" one leads to the multiplication of leukaemia . This in turn leads to a progression of the leukaemia.

This similarity has already been investigated in a previous project by the same group of researchers. "We hope that this will enable us to better understand and fight infectious diseases as well as bone marrow diseases such as leukaemia," says Carsten Riether from the Department of Clinical Research at the University of Bern and the Department of Medical Oncology at Bern University Hospital and the University of Bern.

More information: Christian M. Schürch, Carsten Riether, Adrian F. Ochsenbein: "Cytotoxic CD8+ T cells stimulate hematopoietic progenitors by promoting cytokine release from bone marrow mesenchymal stromal cells," Cell Stem Cell, 20 February 2014, in press.

Related Stories

Recommended for you

Study suggests fish can experience 'emotional fever'

November 25, 2015

(—A small team of researchers from the U.K. and Spain has found via lab study that at least one type of fish is capable of experiencing 'emotional fever,' which suggests it may qualify as a sentient being. In their ...

New gene map reveals cancer's Achilles heel

November 25, 2015

Scientists have mapped out the genes that keep our cells alive, creating a long-awaited foothold for understanding how our genome works and which genes are crucial in disease like cancer.

Insect DNA extracted, sequenced from black widow spider web

November 25, 2015

Scientists extracted DNA from spider webs to identify the web's spider architect and the prey that crossed it, according to this proof-of-concept study published November 25, 2015 in the open-access journal PLOS ONE by Charles ...

How cells in the developing ear 'practice' hearing

November 25, 2015

Before the fluid of the middle ear drains and sound waves penetrate for the first time, the inner ear cells of newborn rodents practice for their big debut. Researchers at Johns Hopkins report they have figured out the molecular ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.