'Reverse vaccine' for Type 1 diabetes seems to pass human test
Attempts at new treatments and cures have focused on suppressing large portions of the immune system — sometimes using powerful drugs developed for other conditions, such as the blood cancer lymphoma. Steinman called this the "big hammer" approach.
"We're trying to do something different," he said. "We want to eliminate just the immune cells that attack the insulin-producing cells in the pancreas."
Steinman and his team designed a molecule that contained the gene for making proinsulin, the precursor to insulin. The molecule also included instructions for triggering the killer cells' response and then shutting it down.
If everything went as planned, the DNA molecule would suppress the killer cells and allow the pancreatic cells to function properly, producing insulin.
After successful trials with diabetic mice, the team prepared to test its vaccine on humans. They selected 80 volunteers ages 18 to 40 who had been diagnosed with Type 1 diabetes within the last five years. After that time, many Type 1 sufferers have already lost all of their insulin-producing cells, Steinman said. (Although many people with Type 1 diabetes are diagnosed as children, the researchers avoided testing their reverse vaccine on kids because of safety concerns.)
Two-thirds of the study volunteers received the reverse vaccine in one of four doses ranging from 0.3 to 6.0 milligrams. The rest of the volunteers got a placebo. Injections were made once a week for 12 weeks.
Throughout the study, both the experimental and placebo groups also received insulin replacement therapy. All subjects were monitore Continue reading