Researchers at the University of Pittsburgh School of Medicine have received a $5 million federal grant to develop a vaccine ingredient that can generate the type of immune response needed to protect against tuberculosis (TB) infection.

Vaccines are primarily made of antigens, which are pieces of proteins from specific bacteria or viruses, and another component called the adjuvant, which stimulates the immune system's production of antibodies against the vaccine antigen, explained principal investigator JoAnne L. Flynn, Ph.D., professor of microbiology and molecular genetics, Pitt School of Medicine, and a member of Pitt's Center for Vaccine Research.

"Nearly all of the vaccines administered today use similar adjuvants derived from alum salts," she said. "That works well when an antibody response to an invading germ is needed, but it is not very effective against the bacteria that cause TB."

An adjuvant can program the correct T-cells of the immune system so they can respond when TB exposure occurs, which could make vaccines against the infection more effective, Dr. Flynn said.

In her project, funded by the National Institutes of Health for five years, she and her team will collaborate with scientists from Copenhagen's Statens Serum Institut, who are developing a new adjuvant that induced CD4 and CD8 T-cell responses in animal studies. They will devise several vaccine formulations with input from Dr. Flynn's team, who will then test them in animal models of TB.

"One way we can now monitor infection is using an imaging technique called PET/CT scanning," she said. "We can track whether vaccinated animals develop pockets of infection called granulomas in their lungs after they've been exposed to TB, and that could speed identification of a vaccine that could be tested in human trials."