(Republished with permission from the St. Louis Post-Dispatch. This article originally ran on Friday, March 24, 2006.)
By Eric Hand
St. Louis Post-Dispatch
Washington University researchers have reaffirmed a simple approach to curing Type 1 diabetes in mice: stop the immune system before it kills off all the insulin-producing cells in the pancreas.
There is a window of time, after the onset of diabetes but before all the cells are destroyed, in which the mouse pancreas can be rescued, said Dr. Emil Unanue, a Washington University immunologist and author of the study, published in the journal Science. “You have a window of time in humans, too,” he said.
The study advances a transplant-free approach to curing Type 1 diabetes with a simple, short and cheap regimen of drugs.
But the researchers, who also added adult stem cells from the spleen into the mouse pancreas, did not find spleen cells morphing into a new source of new pancreatic cells, as was claimed by Harvard University researchers three years ago.
Nearly 21 million Americans have diabetes, according to the Centers for Disease Control and Prevention. As many as 3 million of those cases are Type 1 diabetes, the Juvenile Diabetes Research Foundation says. Type 1 diabetes is an early-onset or juvenile disease where T-cells – the hitmen of the immune system – attack pancreatic cells that make insulin, a hormone necessary to control blood sugar levels.
In 2003, Dr. Denise Faustman, a Harvard University researcher at Massachusetts General Hospital, published work saying that a combination of two substances – a drug and a protein contributed by adult stem cells from the spleen – allowed 22 of 25 mice to be cured of diabetes for at least half a year.
She also reported the signature of the spleen cells in regenerated pancreatic cell clusters. Some people, including Sen. Sam Brownback, R-Kan., who opposes embryonic stem cell work, cited Faustman’s work as an example of the promise of adult stem cell work.
But Unanue and two other independent university labs say they can’t find the signature of regenerated spleen stem cells. They also had less success in curing the mice: In Unanue’s lab, only four of 22 mice were cured. He says controlling the immune system merely lets a few remaining pancreatic cells get a fingerhold to start producing insulin again.
Faustman says she’s “elated” by the new work. She now says that the purpose of spleen cells is probably not that they regenerate into new pancreatic cells, but that they provide the protein that helps kill T-cells.
“You don’t need any stem cells,” she said. “It’s amazing how the message gets messed up.”
Faustman does not know why she detected the stem cells and the other labs did not.
Former Chrysler Corp. Chairman Lee Iacocca, whose wife died from Type 1 diabetes, has helped Faustman raise $9 million of $11.5 million needed to begin human clinical trials that will test the two components to killing the T-cells.
The drugs for the procedure are cheap and would be given for a short period of time. For those reasons, three major drug companies weren’t interested in supporting the work, Faustman said.
She hopes the procedure will eliminate the need for pancreatic cell transplants that currently require long-term regimens of immune suppressant drugs.
About 500 people have received pancreatic cells from cadavers or live donors via a transplant procedure known as the Edmonton protocol, said Peter Cleary, spokesman for the Juvenile Diabetes Research Foundation.
One year after the transplants, four-fifths of the recipients could stop injecting themselves with insulin, Cleary said. But five years after the procedure, that percentage dropped to 10 percent.
Copyright 2006 St. Louis Post-Dispatch, Inc.