Researchers at John’s Hopkins have been working with human immunodeficiency virus (HIV) that is modified to help the immune system recognize the virus and fight it off. Their report, published in the online journal Blood suggests that this research could be a significant step in the development of a vaccine against HIV.
HIV is a virus that targets specific cells in the immune system. Normally, when a virus invades the body the immune system recognizes it as a potential threat and releases chemicals called interferons to warn the rest of the body to defend against the invader. Standard HIV creates such an overwhelming response from the immune system that it releases too many interferons which confuses the defense system and prevents the body from fighting off the virus.
HIV is a string of genetic code inside a carrier that has the ability to attach to and invade cells in the immune system. When the cell is invaded, it becomes a factory to produce multiple copies of the HIV code which is then released into the body, allowing HIV to spread quickly through the immune system.
The human immunodeficiency virus is carried inside a protective coating that contains large amounts of cholesterol. The Johns Hopkins researchers recognized that when immune system cells (white blood cells) contain smaller amounts of cholesterol than normal, HIV was not able to infect them. The researchers used a chemical to remove the cholesterol from the coating on the HIV, creating altered HIV. When placed with human immune cells in a culture dish, the altered HIV did not trigger the release of interferons like normal HIV did.
The lack of excessive interferons allowed the immune system to react as it would with any other virus at the first encounter. This normal response allows the immune system to recognize a potential threat and create defenses to destroy the invader and to remember it as a threat the next time it enters the body. This is the basis of how vaccines are created. Doctors introduce non-active or weakened virus such as for the flu into the body to allow the creation of antibodies in advance of a real attack from the full-strength virus.