Natural Antibody Holds Promise as HIV Treatment

Scientists have identified a component of the "innate" immune system -- defenses that are functional without being exposed to a virus or another outside invader -- that the body uses to combat HIV. The discovery may open the door to a new type of treatment for HIV, since it is possible to grow the component in the laboratory, according to Dr. Ronald Winston, president of both the Switzerland-based Institute for Human Genetics and Biochemistry and the Harry Winston Research Foundation in New York. These antibodies in the blood defend against HIV by reacting with certain parts of the virus, Winston explained. But eventually, as an HIV-positive person develops full-blown AIDS, he noted, the body stops producing large numbers of antibodies.

Innate immunity is a relatively new area of study of the body's immune system. "The problem with the AIDS virus," said Winston, is that "it's constantly re-camouflaging itself with a new protein code." When the virus changes its camouflage, "the body doesn't recognize it anymore," which makes developing a vaccine difficult, he explained. Winston and his colleagues suspect that a person with HIV starts to get sick as the body begins to lose its innate immunity to the virus. But the researchers speculate that if adequate levels of the antibodies could be restored, it might be possible to prevent HIV-related illness. "We show a very specific therapeutic action" of these antibodies, said lead author Dr. Toby C. Rodman of Rockefeller University. She explained that the antibodies inhibit the HIV Tat protein, which is responsible for some of the "most disastrous" effects of the virus. Since the antibodies block this deadly protein, "they may be a source of therapeutic agents," she said.

After isolating the antibodies in human beings, the researchers were able to produce them in the lab. Using cells taken from umbilical-cord blood, the researchers grew the innate anti-HIV antibodies. The next step is to produce enough of the antibodies to test them as a treatment for HIV, Winston explained. "We would like to talk to a bioengineering firm to figure out how to get this toward clinical trials," he said. The full study appears in Experimental Hematology (2001; 29: 1004-1009).

Back to other CDC news for August 22, 2001

Previous Updates