Scientists use adult stem cells to replace immune system and bone marrow of mice
The collaborative experiments by researchers at the University of Minnesota and Stanford University offers the promise of new therapies for people in the future.
For decades, researchers have tried in the lab to expand hematopoietic stem cells, which give rise to the blood system. The success in this venture would mean increasing the supply of cells available for bone marrow transplant patients.
During the course of study, Dr. Catherine Verfaillie and her colleagues isolated multipotent adult progenitor cells (MAPCs) from the bone marrow of mice, and expanded them for at least 80 doublings in the lab.
They then transplanted the cells into mice that received radiation and thus had no immune system.
"The cells not only survived when transplanted but they completely repopulated the blood system of the mice," Verfaillie said.
The researchers said that the MAPCs did not differentiate into other cell types, such as liver or brain cells, nor did they form tumours in any animals.
"These experiments point to potential precursors of blood forming stem cells in an unexpected population of cultured cells," said Dr. Irving Weissman, the director of Stanford's Institute for Stem Cell Biology and Regenerative Medicine.
"Scientists must now understand that mouse MAPCs can make normal blood, and we need to explore how they do it. It is very important to note that MAPCs were not themselves radioprotective, thus they alone could not be used in patients in whom the bone marrow is totally eliminated due to radiation or chemotherapy, but it is still remarkable that they can give rise to blood cells," Weissman added.
Although more research needs to be done and studies need to be replicated with human MAPCs, the researchers believe that their findings offer promise of new therapies for people in the future.
"I am pleased to see this science replicated at other research universities. Now there is further confirmation that the MAPCs could be a valid source of new therapies," Verfaillie said.
She said that it was important that scientists continued pursuing all types of stem cell research, adult and embryonic, because it was still not clear as to which cell type would prove most promising for treating a particular disease.
The study has been published in the Journal of Experimental Medicine
One Republican legislator adds that Americans shouldn't be forced to pay for that which they find ``morally reprehensible.''
What shameless hypocrisy. This same administration continues to compel American taxpayers to pay hundreds of billions to fund the war in Iraq, a tragedy that has destroyed the lives of countless Americans and Iraqis. Which destruction of life is more morally reprehensible?