A new technique of combating HIV infection has been discovered by scientists at University of California-San Francisco and the University of Toronto.

An HIV infection relies on the remnants of ancient viruses, human endogenous retroviruses (HERV) that have become part of the genome of every human cell. Nearly 8 percent of DNA in human genome consists of viral genes, which are already present from millions of years ago. When modern virus attacks a cell, the ancient genes get triggered off producing tiny proteins that move to the surface of cell after HIV infection and indicate a distinctive signal –called HERV.

According to the study, HERV were present in 15 out of 16 participants who were HIV+ and not yet used antiretroviral drugs. 4 HIV- participants displayed no evidence of signals that indicated that their immune systems might be putting control over HIV.

Douglas Nixon, UCSF immunologist and his team said that the signals from ancient viruses consistently are found on the cells infected with HIV that are where the potential of vaccine that attacks HERV might be successful. Scientists might be able to eliminate the HIV-infected cells if they could develop a vaccine, which stimulates a strong response against these ancient viral signals.

The evidence shows that HIV infection could enable HERV expression by cutting off the normal controls that keep HERV in check.

The research team is also observing a small subset of people who are able to control HIV naturally, known as elite controllers, who produce high levels of HERV proteins. In many HIV-infected individuals, the infection fighting T cells are able to target HERV expressing cells. Scientists believe that their findings could lead to a vaccine targeting HERV that kills HIV infected cells.

Keith E. Garrison, PhD., post-doctoral fellow in UCSF’s Division of Experimental Medicine, and study co-author, said, “One important limitation to a T-cell vaccine targeting HIV itself is that HIV exists in so many variations and is constantly mutating. If we can find other ways for the immune system to target HIV-infected cells, we can overcome this problem in making an HIV vaccine. HERV may provide us with a good target to test.”

Nixon explained that any vaccine developed to attack an ancient virus has the potential to attack amiable cells, which can stimulate a dangerous autoimmune response. More research is required before a potential vaccine of this nature would be available for testing in humans. The study is published in November 9, 2007 issue of journal “PLoS Pathogens.”

Reportedly, Ugandan President Yoweri Museveni said circumcision should not be promoted as a way to prevent HIV transmission because it could encourage recklessness among youth.

At a Youth Activist Forum conference, Museveni said that he would continue to promote the ABC strategy for HIV prevention that stands for abstinence, be faithful and use condoms. He also encouraged youth to get married immediately after completing their education.