The researchers at Lund University in Sweden have made it possible to monitor large blood cell populations by assigning a barcode to stem cells. They also monitor individual blood cells, and study the changes over time. It has been discovered that stem cells go through different stages where their ability to restore immune cells varies. This provides important information for the research and treatment of leukemia and autoimmune diseases.
It is suggested by studies in mice, that some of our white blood cells are only formed during the fetal period, and stay with us for the rest of our lives. Those blood stem cells in the embryo are especially capable of maturing into a proper immune system, but the question as to why they do not continue to do so in adults, has been discussed among researchers for a long time. The research group at Lund University believes they are now one step closer to finding the answer to this.
They were able to track their performance over long periods of time by assigning a “barcode” To the stem cells. They can also see which cells in the blood and immune system can be induced. Otherwise, without the barcode, only a bunch of red and white blood cells is seen, without knowing how they are related. They can now track which stem cell has given rise to which subsidiary cells, and to distinguish the family tree in the blood, according to Joan Yuan, research group leader.
Researchers are enabled by the barcodes to see how individual stem cells in the blood differ from one another, and how their functions can change with age. The white blood cells are only formed in the embryo, and one theory has been that they originate from specialized stem cells that are only active during fetal life. The research group can now show that this is not the case, with the help of barcodes. Stem cells, within adults, have lost their ability to regenerate the entire immune system, even though the same stem cells exist. Adding a protein that is normally only found in the stem cells of a fetus, they were able to reconstruct their capacity to produce white blood cells, according to Trine Kristiansen, doctoral student and lead author of the study. This particular study was recently published in the journal Immunity. The research shows that the stem cells undergo various stages in which their ability to reproduce all types of immune cell changes, so it is possible to turn back the clock and, with the help of protein, recreate a fetal-like status. Leukemia could benefit from this information, as for which one of the treatment methods involves a bone marrow transplant. The patient’s blood system is replaced with that of an adult donor, where they might lose the B cells that are only produced in fetuses.
The immune system is no longer complete without these antibody-producing white blood cells. The individual then becomes increasingly at risk of developing immune system disorders, that can lead to severe infections and autoimmune diseases, as the blood cells produce special antibodies that have the important function of removing dead cells from the body.
Millions of blood cells die every day, and can emit DNA and other debris that causes inflammation, if not taken care of by the white blood cells. This is a step towards understanding, which processes create a proper immune system for those who suffer from blood diseases. The full study was published August 16, 2016.
-Dr Fredda Branyon