Research team's findings may lead to safer vaccines
Thomas C. Mitchell, Ph.D., (far left) and his research team at UofL.
A team from the University of Louisville has found clues that explain how one vaccine additive works to produce faster, stronger and longer-lasting immunity than the vaccine alone.
The team's results, published June 14 in Science magazine, show that the immune systems of mice injected with an adjuvant - a vaccine additive that boosts immune function - called Monophosphoryl Lipid A (MPLA) developed strong immune responses without toxic side effects.
Researchers found evidence that MPLA has unexpected anti-inflammatory properties.
"These results have important implications for future vaccine development," said Thomas C. Mitchell, Ph.D., associate professor of microbiology and immunology and Barnstable-Brown Chair in Diabetes Research.
"One of the key challenges in developing vaccines is finding a formula that boosts immunity while avoiding harmful side effects," Mitchell said. "Current vaccines maximize patient safety, but may not maximize immunity."
The team measured the immune response in mice treated with MPLA and a related compound, LPS, which is not approved for human use due to toxic side effects.
They showed that MPLA matches LPS in stimulating the multiplication of cells that can recognize and destroy harmful bacteria and viruses.
Those cells, in turn, are strong producers of a protein that creates a feedback loop allowing the immune cells to proliferate and attack the source of infection.
At the same time, MPLA does not seem to have the toxic side effects seen with the use of LPS.
The only vaccine additive currently approved for use in the United States, alum, is widely viewed as a safe agent but does not maximize immunity.
The UofL team includes five researchers from the Institute for Cellular Therapeutics and one from the School of Dentistry's Oral Health and Systemic Disease research group.
According to Mitchell, the researchers hope their results will lead to a new generation of vaccines that will allow patients to be better protected from disease for longer periods of time and with fewer injections.
