August 9, 2011
Out of Body Experience for Stem Cells
(Ivanhoe Newswire) -- New research finds that growing blood stem cells in the laboratory for about a week may help to overcome one of the most difficult roadblocks to successful transplantation, immune rejection. The study may lead to more promising therapeutic strategies for transplanting blood stem cells.
Hematopoietic stem cells (HSCs) are cells that can give rise to all of the different types of blood cells. Transplantation of HSCs has been used to treat leukemia, lymphoma, and other types of cancer, as well as some autoimmune diseases. However, there is a significant risk that the transplanted cells will fail to be incorporated into the host, or that the new cells will be rejected by the immune system and the patient will develop life-threatening "graft-versus-host" disease. Although scientists have identified some causes of transplant failure, many questions remain unanswered. "The resolution of these questions will promote the understanding of the immunology of blood-forming stem cells and other stem cells and greatly improve the practice of transplantation," senior study author, Dr. Cheng Cheng Zhang from the University of Texas Southwestern Medical Center, was quoted as saying.
The researchers went on to look at the mechanism that underlies this effect, and found that the lab-grown HSCs started to produce a specific immune system inhibitor on their surface that contributed to the improved transplantation efficiency. "This work should shed new light on understanding the immunology of HSCs and other stem cells and may lead to development of novel strategies for successful allogeneic transplantation of human patients," concluded Dr. Zhang. "If donor human HSCs can be expanded in culture and engraft non-matched or low-matched patients without graft-versus-host disease, this strategy will possibly lead to an ultimate solution to problems in allogeneic transplantation."
SOURCE: Cell Stem Cell, published online August 8, 2011