Oscar-winning actress Julianne Moore said her experience of caring for someone infected with the AIDS virus had spurred her decision to help promote the documentary "5B" about the unsung heroes who looked after AIDS sufferers in the 1980s.

The film, screened during the first week of the Cannes Film Festival, tells the story of Ward 5B at the San Francisco General Hospital, the first specialist care unit for people with HIV/AIDs in the United States.

In an interview with Reuters at Cannes, Moore, 58, said she lost a friend to the virus just after graduating from college.