Twenty years after its discovery, AIDS still has researchers searching for key to a cure

Boston [06.15.01] -- After two decades of studying and fighting AIDS, researchers have learned an important lesson: the HIV infection is a formidable opponent. Currently, 37 million people are suffering from various stages of HIV and the numbers are expected to increase five-fold over the next 20 years. While a cure hasn't been found yet, a Tufts scientist is helping make huge strides in understanding the ways the virus works.

   According to John Coffin -- a leading AIDS researcher at Tufts and the National Cancer Institute -- the HIV virus uses a host of tricks to out-smart the human body, making it one of the most difficult viruses to fight.

   Sugar, for example, helps HIV sneak past the immune system.

   The proteins on the outside of HIV "have more sugar on them than any other protein molecule we know of," Coffin told New York's Newsday earlier this month.

   The newspaper reported that the "sugar coating" allows the virus to sneak "past the immune system sentries, looking nothing more dangerous than a microscopic M&M candy."

   Once inside the body, HIV is able to thrive, despite the immune system's best attempts to fight it.

   "There are very few viruses that maintain a persistent replication in the face of an active immune response," Coffin said in an International Herald Tribune article. "That's the niche this virus has evolved into."

   The sugar may be responsible for protecting the virus from attacks as well.

   According to the New York Times, "[Coffin said] the AIDS virus is like a Tootsie Pop -- a hard shell of sugar covers the good stuff inside. And antibodies, made to block the virus proteins, can never penetrate its sugar shell to do their job."

   The Tufts molecular biologist explained that the HIV virus looks for a home in the immune system cells, specifically targeting the CD4 cells -- which play a crucial role coordinating the body's antibodies.

   As the virus replicates inside the CD4 cells and its levels increase in the body, the CD4 cells die, weakening the immune system. Some scientists believe that the key to fighting AIDS is to destroy the HIV-infected cells.

   But Coffin said the solution may not be easy, since HIV can hide in the CD4 cells for years.

   "These are like embers that are left behind in a fire," Coffin said in a Newsday article. "If the fire department leaves too soon, the embers can start the fire right back up again."

   Quick to mutate and evolve, HIV is constantly presenting a "new face" to the body's immune system. And that renders many HIV drugs useless, Coffin told Newsday.

   "If something works against HIV, the virus will evolve to get around it," he said.