Two presentations on Emory research at last week’s AIDS Vaccine 2010 conference concerned adjuvants. These are substances that act as amplifiers, stimulating the immune system while keeping its focus on the specific components of a vaccine.
Charlie Janeway (1943-2003)
Immunologist Charlie Janeway once described adjuvants as immunology’s “dirty little secret,” because for a long time scientists did not know how they worked. Some adjuvants can sound irritating and nasty, such as alum and oil emulsion. Alum is the only vaccine adjuvant now licensed for human clinical use in the US. Over the last few years, scientists have learned that adjuvants rev up what is now known as the “innate immune system,” so that the body knows that the vaccine is something foreign and dangerous.
Rama Rao Amara, a vaccine researcher at Emory Vaccine Center and Yerkes National Primate Research Center, and Harriet Robinson, former head of microbiology and immunology at Yerkes and now chief scientific officer at the firm GeoVax, both described extra ingredients for the DNA/MVA vaccine that Robinson designed while at Yerkes in collaboration with NIH researchers.
Imagine that HIV was a “normal” virus. An infection begins and the body responds, without getting trapped in a cycle where CD4+ T cells are consumed and the immune system is crippled.
SIV can infect sooty mangabeys but it doesn't cripple their immune systems.
The attractiveness of this idea explains some of why scientists are interested in sooty mangabeys and other non-human primates. HIV’s relative SIV can infect them, but they usually don’t develop immunodeficiency.
At last week’s AIDS Vaccine 2010 conference, Cynthia Derdeyn reported her laboratory’s recent results investigating sooty mangabeys, which don’t develop high levels of neutralizing antibodies against SIV when infected. Derdeyn’s group at Emory Vaccine Center andÂ Yerkes National Primate Research Center studies how HIV and SIV evade the immune system.
Bali Pulendran, PhD
A tiny invader, perhaps a virus or a microbe, enters the body, and our ancient immune system responds. But how does it know what kind of invader has landed? And once it knows, how does it decide what kind of immune response it should launch?
In humans, the immune system consists of two parallel systems working with one another to fend off invaders. One is the innate immune system, the other the adaptive immune system.
Immunologist Bali Pulendran studies how those two systems work together to identify and respond to all kinds of intruders including pathogens, viruses and microbes.
Itâ€™s the innate immune systemâ€™s job to recognize the first signs of infectionâ€”that is, the moment a pathogen enters the body. â€œIn a sense they act as smoke detectors if you will,â€ says Pulendran. â€œLittle alarms.â€