HOUSTON -- (June 10, 2010) Most of the time, the body's blood-forming (hematopoietic) stem cells remain dormant, with just a few producing blood cells and maintaining a balance among the different types.
However, invading bacteria can be a call-to-arms, awaking the sleeping stem cells and prompting them to produce immune system cells that fight the foreign organisms. The "bugler" that awakes the stem cells in this battle is gamma interferon, a front-line protein defender against bacterial infection, said researchers from Baylor College of Medicine (www.bcm.edu) in a report that appears in the current issue of the journal Nature (www.nature.com).
"We are looking at the normal function of stem cells," said Dr. Margaret Goodell (www.bcm.edu/star/index.cfm?pmid=2947), professor of molecular and human genetics at BCM and director of the Stem Cells and Regenerative Medicine (STaR) (www.bcm.edu/star/index.cfm?PMID=0) Center. She is the report's senior author. "One of those is to respond to an infection."
Goodell and her colleagues knew that cells farther along in the differentiation process responded to infection, increasing the production of immune cells.
"We were sure there was a mechanism by which hematopoietic stem cells respond to infection, but it was not obvious," she said. They started their work with gamma interferon because they knew it played an important role in bacterial infection.
The collaboration and talents of two researchers in her laboratory first co-authors Drs. Megan T. Baldridge and Katherine Y. King facilitated the work with mice that led to this finding, said Goodell. Both are at BCM.
"I think our findings represent an exciting new avenue for studying hematopoiesis," said King. "By viewing the hematopoietic stem cell as the source
|Contact: Glenna Picton|
Baylor College of Medicine