Vaccine May Stop Immune Attack in Type 1 Diabetes
Early trial found it boosts insulin production, appears safe
By Serena Gordon
WEDNESDAY, June 26 (HealthDay News) -- A new type of vaccine may stop the autoimmune attack that occurs in people with type 1 diabetes, researchers report.
Although an initial trial of the vaccine wasn't able to free anyone from their daily insulin injections, it did boost insulin production, which could help prevent some of type 1 diabetes' most devastating complications.
Instead of increasing the immune system's activity like the polio or influenza vaccine does, the new vaccine turns off a portion of the immune response, acting as a reverse vaccine. The researchers were able to isolate a part of the immune response that only seems to be involved with type 1 diabetes, according to the study. That means the vaccine likely wouldn't have the risks that medications that suppress the immune system do.
"We were able to destroy the rogue cells that are attacking the insulin-producing cells without destroying any other part of the immune system, and that's truly exciting," said senior study author Dr. Lawrence Steinman, a professor of pediatrics and neurology and neurological sciences at Stanford University School of Medicine.
"Once the immune attack is stopped, I believe there's great potential for recovery in the beta cells," Steinman added.
Beta cells in the pancreas produce the hormone insulin. In people with type 1 diabetes, it's believed that the immune system mistakenly destroys the healthy beta cells, leaving the person with no or too little insulin.
Insulin is a crucial hormone because it's involved in the metabolism of the carbohydrates. It allows the glucose (sugar) from those carbohydrates to fuel the cells in the body and brain. Without enough insulin, a person will die. That's why people with type 1 diabetes must take multiple daily injections of insulin, or deliver insulin through a catheter inserted under the skin that's attached to an insulin pump.
The vaccine was designed by changing a piece of immune-system DNA so that it would shut down the immune system's response to signals in the body that have previously triggered the mistaken destruction of beta cells. These signals come from fragments of a protein (peptides) called proinsulin, which is found on the surface of beta cells. Proinsulin is a precursor to insulin.
"We just wanted to throw the off switch for the one cell being attacked," Steinman explained.
The researchers recruited 80 volunteers diagnosed with type 1 diabetes during the past five years. They were randomly placed in one of five groups. Four groups received various doses of the vaccine, and the fifth group received placebo injections. Shots were given weekly for 12 weeks.
No one in the study was able to stop using insulin. "That's a possible goal, but it's too early to start saying cure," Steinman noted.