The Global Fund was started five years ago by the United Nations as an innovative partnership of governments, nonprofits and the private sector to fight AIDS, tuberculosis and malaria. The fund, which has invested more than $10 billion (U.S.) in 136 countries, has begun to run out of money.  Rock star Bono, lead singer of the band U2, is leading a commercial venture with well-known private companies called RED that is designed to replenish and stabilize income for the Global Fund.