UCLA STUDY MAY PROVIDE CLUES TO RESISTANCE TO HIV : SUBSTANCE FOUND IN EVERYONE LINKED TO IMMUNITY.

Byline: Keith Stone Daily News Staff Writer

UCLA researchers announced Tuesday that they have identified a substance found in everyone that seems to lead the battle against the virus that causes AIDS, but eventually is defeated.

What's important about this finding is that it reveals new clues about the body's attempt to fight the virus and eventually could lead to the development of a vaccine, according to researchers at the University of California, Los Angeles.

People with normal levels of the naturally occurring antibody VH3 are as many as five times less susceptible to infection by human immunodeficiency virus than those deficient in the antibody, said Lee Goodglick, a co-author of the study and co-director of the Human Tissue Research Center at UCLA.

Researchers said that even those people with normal or high levels of VH3 still are at risk for HIV infection and therefore should take precautions.

``We hypothesize that these antibodies are at least one type of natural immunity against the virus, and this may be one of the first lines of defense,'' Goodglick said.

``If people have, for whatever reasons, lower amounts of these antibodies and a lowered defense system, the virus may have a better chance to take hold,'' Goodglick said.

The finding, published today in the Journal of Clinical Investigation, focused on 252 men, including a group that has been relatively sexually promiscuous but nonetheless remained free from infection.

``We found they had levels of these antibodies that were more or less in the same range as the low-risk population,'' Goodglick said.

The study points out that VH3 alone cannot prevent infection. ``This observation indicates that naturally occurring (VH3) antibodies are only one factor in resistance to infection,'' the study says.

Other factors include the strength and amount of the virus, genetic differences in the immune system and the presence of unrelated infections that could weaken the immune system, the study says.

Researchers suspect that VH3 works by coating the virus as it enters the body and then guiding it to germ-killing cells in the body, Goodglick said. If that is correct, then large amounts of the virus would overwhelm even a normal level of the VH3 antibody, he said.

Regardless of the antibody's role in warding off the virus, its level in the blood could be used as a gauge of susceptibility to infection, Goodglick said.

Participants in the study were chosen from a nationwide study of homosexual men and another study of uninfected men.