Spleen Cells Fail to Treat Diabetes
But Insulin-Making Islet Cells Can Recover in Type 1 Diabetes
Unanue's team at Washington University, a team led by Louis Philipson, MD, PhD, at the University of Chicago, and a team led by Diane Mathis at Harvard's Joslin Diabetes Center all tried to repeat the Faustman experiment.
It didn't work. None of the three teams got the same result. The spleen cells, it turns out, didn't become islet cells.
That means the mice should have died once their temporary islet transplants were removed. But a few of them didn't die. Instead, their islet cells recovered and began making enough insulin to keep the animals alive.
No Cure, but a Big Step Forward
Apparently, a few islet cells (or precursor cells that can become islet cells) survive the immune attack. When the immune attack is put on pause, the cells grow and start making insulin.
"The positive thing is that, yes, the destructive immunologic process can be controlled," Unanue says. "Even when you have a fully diabetic mouse, there is still a window of time in which you can rescue [islet]-cell function."
How does Faustman feel about having a major part of her findings refuted? She's delighted.
"We are elated by these three stories coming out," Faustman tells WebMD. "These papers now show that others, too, can cure these end-stage diabetic animals. And they show the cure is sometimes totally driven by regeneration of islets in the pancreas. All three show they can do it independent of live, introduced stem cells. It is extremely good news."
Unanue says while the destructive immune process of type 1 diabetes can be put on hold, it's still not possible to stop it once and for all. And even if scientists leap that hurdle, it's still probable that this will rescue islet cells in people who've had type 1 diabetes for many years. They likely will need some kind of islet transplant -- or some way to encourage other precursor cells to become insulin-making cells.
That last idea isn't moonshine. For example, a recent study in Switzerland showed that human fat tissue contains cells that can become insulin-making cells.