Adult monocyte white blood cells can be converted into stem cells that can become many other cell types.
The particularly powerful – and very scarce – flexible forms of stem cells needed for medical research and treatment may now be both plentiful and simple to produce, with a new technology developed at the U.S. Department of Energy’s Argonne National Laboratory – and the source is as close as your own bloodstream.
These flexible stem cells, able to morph into a variety of cell types, are called “pluripotent,” and before this Argonne research, they have been found only in fetal tissue, which is limited, and in bone marrow, which is difficult to collect. Pluripotent stem cells are important because they can generate all types of tissues found in the body, and the Argonne-developed technology can produce them from adult blood cells.
The finding may eventually offer researchers a practical alternative to the use of embryonic stem cells for research, drug discovery, and transplantation.
Argonne scientist Eliezer Huberman and his colleagues, Yong Zhao and David Greene, examined adult monocytes, a type of white blood cells that act as precursors to macrophages. The researchers found that when monocytes were exposed to a growth factor, they created a set of pluripotent stem cells. After cultivating the stem cells, the scientists were able to make the cells “differentiate” into nerve, liver, and immune system tissue by delivering more growth factors.
“Because of its great promise in medicine, I’m prouder of this work than of anything else I’ve done,” Huberman said.
The research is being published in the Proceedings of the National Academy of Sciences.
Storing the precursor cells in liquid nitrogen had no effect on their differentiation later. Because monocytes can be easily gathered from a patient's own blood supply, the researchers suggest that treating disease with a genetic match to prevent rejection may be possible in the future.
This means that the material should produce valuable candidates for transplantation therapy, useful to replenish immune cells that have been eradicated by cancer therapy or to replace neuronal tissue damaged during spinal cord injury, stroke, Alzheimer’s or Parkinson’s disease.
Funding for the research is from the National Institutes of Health. The researchers have applied for a patent on the new technology.
This is a very exciting development. By avoiding cloning or the use of embryos or fetal tissue this technique may not provoke as much opposition on ethical grounds. There is still a possibility that some will ethically object. If these cells turn out to be capable of developing into a fetus some might argue that application of the growth factor is essentially creating an embryo.
It is premature to conclude that these cells are pluripotent and as fully useful as embryonic stem cells. Other labs are going to have to confirm that the cells can become many more cell types. But if the cells can do that then the next question that needs to be asked is whether they are as youthful as stem cells taken from an embryo or umbilical cord. Tests need to be done to measure telomere sizes, ability to go thru many cell divisions, speed of cell division, and other indicators.
|Share |||Randall Parker, 2003 February 24 12:47 PM Biotech Manipulations|