New vaccine promises to treat AIDS

Researchers have developed a vaccine that seems to have the capability of completely clearing an AIDS-causing virus from the body.

The promising vaccine candidate that is being developed at OHSU’s Vaccine and Gene Therapy Institute is being tested through the use of a non-human primate form of HIV, called simian immunodeficiency virus, or SIV, which causes AIDS in monkeys.

Louis Picker, M.D., associate director of the OHSU Vaccine and Gene Therapy Institute, said that the latest research suggests that certain immune responses elicited by a new vaccine may also have the ability to completely remove HIV from the body.

The Picker lab’s approach involves the use of cytomegalovirus, or CMV, a common virus already carried by a large percentage of the population. In short, the researchers discovered that pairing CMV with SIV had a unique effect.

They found that a modified version of CMV engineered to express SIV proteins generates and indefinitely maintains so-called “effector memory” T-cells that are capable of searching out and destroying SIV-infected cells.

T-cells are a key component of the body’s immune system, which fights off disease, but T-cells elicited by conventional vaccines of SIV itself are not able to eliminate the virus.

The SIV-specific T-cells elicited by the modified CMV were different. About 50 percent of monkeys given highly pathogenic SIV after being vaccinated with this vaccine became infected with SIV but over time eliminated all trace of SIV from the body.

In effect, the hunters of the body were provided with a much better targeting system and better weapons to help them find and destroy an elusive enemy.

The research has been published today by the journal Nature.