Man Immune to HIV Helps Scientists Fight against Virus

A man best known for staying alive during the early days of the AIDS epidemic, passed away last month, according to KAWC.

Stephen Crohn, 66, helped researchers uncover vital clues about HIV and how to stop it. His partner was one of the first people to die from AIDS in 1978. Over the years, Crohn watched boyfriends and acquaintances die from the disease, but he never got sick. Knowing that there was something unique about himself, Crohn volunteered to be studied. Eventually, scientists realized that Crohn had a genetic anomaly that made him resistant to HIV infection. Less than 1 percent of the population carries this protective mutation.

Immunologist Bill Paxton was one of the first scientists to work with Crohn at the Aaron Diamond AIDS Research Center in New York. He figured out that some of Crohn's immune cells, called CD4, literally blocked the virus. "I couldn't infect the CD4 cells," he told The New York Times. "I'd never seen that before."

HIV normally enters an immune cell by tugging on two receptors on the cell's surface. Scientists ultimately figured out that one of those receptors on Crohn's cells was shortened and not accessible to the virus. Without the receptor, HIV couldn't infect his cells. This genetic change is called the delta 32 mutation. Its discovery has helped researchers develop the anti-viral drug maraviroc and devise the first experimental strategy for curing HIV.

Crohn was an artist and freelance editor. His paintings have been exhibited in New York, San Francisco and elsewhere. He committed suicide last month. His sister, Amy Crohn Santagata, told The New York Times that he suffered from survivor's guilt.