New research may explain HIV infection process

Nearly every graduate of eighth grade health class could explain how one contracts the HIV virus. But even the world's leading AIDS researchers cannot explain the exact biological process that takes place when HIV infects a cell. However, a paper by University Medical Center researchers to be published in the next issue of Cell may provide some answers. In the paper, Robert Doms and his colleagues, along with a team of scientists from Harvard University, point to a series of proteins on the surface of white blood cells that enables the virus to enter the cell. The proteins identified are called CKR2b, CKR3 and CKR5. The breakthrough may eventually give researchers new ammunition in the search for new methods to prevent the spread of HIV. "Discovery of these proteins opens up whole new ways of trying to prevent HIV infection by blocking the virus from getting into the cell in the first place," Doms said in a statement released by the Department of News and Public Affairs for the Health System. The report may also help to explain why some people are not infected by HIV despite frequent exposure to the virus. Past research has already lead to the discovery of two receptor proteins which enabled HIV to infect a cell. One, called CD4, has been known for years. The other, called fusin, was just identified last month by government researchers. Fusin is used by the strains of HIV associated with late-stage infection. However, the proteins identified by the University researchers are associated with all stages of infection and, consequently, may help to explain how the virus is transmitted from one person to another. Since HIV was identified 12 years ago, AIDS researchers have been trying to explain how the virus invades the white blood cells, which are the body's infection fighters. Part of the puzzle has been known for more than a decade. The HIV virus attaches itself to a protein on the surface of some white blood cells called CD4. But for the HIV to actually enter and infect the cell, researchers determined that there must be other receptor proteins. That is where the recent discoveries enter into the situation. According to the Penn researchers, the newly-identified proteins help to explain this infection process.