Scientists at The Scripps Research Institute in La Jolla have helped identify two rare and potent human antibodies to HIV, the virus that causes AIDS.
Their discovery could finally reveal a chink in the armor of the deadly virus and lead to development of an effective, broad-based AIDS vaccine.
The research will be published in Friday's edition of the journal Science. The Scripps team worked with those from the International AIDS Vaccine Initiative and the biotechnology companies Theraclone Sciences in Seattle and Monogram Biosciences in San Francisco.
Before this latest announcement, only five of these pathogen-busting proteins – called broadly neutralizing antibodies, or bNAbs – had been pinpointed in people. None were identified in the past decade.
While analysis of the new antibodies is still in its earliest stages, the preliminary findings suggest dramatic potential.
Unlike other types of antibodies – molecules created by the immune system to seek out, neutralize and help kill specific invaders – bNAbs can block infection from many kinds of HIV.
Only a minority of people with HIV produce these mega antibodies in natural abundance, so scientists must come up with a way to artificially induce their production in a vaccine.
“I believe that no effective vaccine against HIV can be developed without being able to elicit a broadly neutralizing antibody response,” said Dr. Douglas Richman, director of the Center for AIDS Research at the University of California San Diego. He wasn't involved in the new study.
The HIV pandemic has grown exponentially for more than three decades.
Before the early 1980s, there were no known cases of HIV or AIDS. Today, about 33 million people worldwide are infected with the virus, with almost 3 million new patients reported in 2007 alone. Roughly 2 million people die from AIDS complications annually, according to the international AIDS charity AVERT.
The vast majority of infections occur in sub-Saharan Africa. Incidence rates of HIV and AIDS have declined in the United States and Europe, mainly because of improved prevention efforts and modern treatment methods. Nonetheless, the Centers for Disease Control and Prevention estimates that 40,000 new HIV infections still occur each year in this country.
HIV triggers the latent but almost inevitable development of AIDS – acquired immune deficiency syndrome, a progressive and often fatal disease for which there's no cure. Unless the infection is attacked quickly with medications, it becomes embedded in the body and erupts into a full-blown disease months or years later.
“For the most part, the natural immune response against HIV is completely inadequate,” Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, wrote last year in The New England Journal of Medicine.
Scientists widely consider HIV as the toughest and most mutable pathogen they've ever faced.
“It's the most variable of viruses. It has evolved the most tricks to avoid detection and destruction,” said Dennis Burton, a professor of immunology and microbial science at The Scripps Research Institute. He's also scientific director of the institute's Neutralizing Antibody Center, the only such enterprise in the world.