Study: Hope alive for AIDS vaccine

Researchers from the Dana-Farber Cancer Institute and Harvard Medical School (HMS) have prompted human immune cells to attack HIV protein fragments, showing that the long-sought vaccine to protect against AIDS is still a possibility.

Researchers using advanced data-analysis programs identified five protein fragments from HIV – the virus that causes AIDS – that promote a strong immune response from the cells of people who have never been exposed to the HIV virus before.

That means, researchers said, that creation of a vaccine to protect unexposed individuals from infection with HIV appears possible. Researchers conducted their study using fragments from HIV-1, the more virulent of the two strains known to cause AIDS.

For 20 years, scientists have fought the disease and sought ways to prevent the AIDS virus from devastating patients’ immune systems. It is the virus’s destruction of the body’s immune response that opens patients to a variety of opportunistic infections that run rampant and, ultimately, cause death.

Researchers had thought that human immune system cells don’t fully recognize the HIV-1 virus and so can’t eliminate it from the body after infection. The new study shows that isn’t the case and suggests shifting efforts toward creating a vaccine aimed at uninfected individuals.

The study, published in the online journal Medical Immunology, was led by Dana-Farber’s Pedro Reche, an instructor in medicine at HMS, and by Derin Keskin, a research fellow in medicine at HMS.

“It has been unknown for 20 years why HIV-1 becomes persistent and isn’t cleared from the bodies of AIDS patients,” says Medical Immunology’s editor, Kendall Smith, chief of the Division of Immunology at Weill Medical College at Cornell University. “This study suggests that in HIV-positive people, the immune system cells that respond to HIV-1 are either deleted or have lost the ability to recognize and home in on major parts of the virus.”

If these findings hold true in follow-up studies, they suggest that exposing healthy people to HIV-1 proteins might train their immune system to attack the virus and prevent them from developing AIDS if exposed to HIV-1 in the future, Reche said.

Senior author of the study is Professor of Medicine Ellis Reinherz, of Dana-Farber and Harvard Medical School. Other co-authors, all of Dana-Farber and Harvard Medical School, are Rebecca Hussey, research associate in pathology; Petronela Ancuta, research fellow in pathology; and Professor of Neurology Dana Gabuzda.