Feline AIDS virus could be the key to an effective human HIV vaccine

Researchers at the University of Florida and University of California, San Francisco, have made some interesting discoveries in the research on a new vaccine against HIV. The study, published in Journal of Virology, reveals that  blood from human subjects infected with HIV causes an immunological reaction against a feline AIDS virus protein.

Janet Yamamoto, a professor of retroviral immunology at the UF College of Veterinary Medicine and the study ‘s corresponding author, said that one of the major reasons why it has not been possible until now the development of an effective vaccine against HIV is because we do not know which parts of HIV we must combine in order to produce the most effective vaccine.

The vaccine that researchers are working at the moment consists of T cells that activate an immune response in T cells from HIV-positive individuals against the feline AIDS virus. Researchers are manipulating in fact peptides that are small pieces of protein that can stimulate T cells of the body to recognize viral peptides in infected cells and destroy them. But as stated Yamamoto, HIV is composed of several peptides and not all peptides can be used as vaccine components. In previous experiments, researchers used whole HIV proteins as vaccine components but none was effective enough so that it becomes a commercial vaccine.

According to Yamamoto, in humans, some peptides induce immune responses, that is either they stimulate HIV infection or they have no effect at all, while others may have anti -HIV activities that are lost when the virus changes or acquires a mutation to avoid the immune system. Therefore, researchers are investigating those viral peptides in the feline AIDS virus  that do not change or mutate. Yamamoto said they surprisingly managed to find some of the feline AIDS virus peptides that are effective in producing T cells that fight HIV.

Researchers isolated T cells from HIV-positive individuals and incubated these cells with different peptides essential for the survival of both human and feline HIV viruses. Then researchers compared the immune responses found with feline immunodeficiency virus ( FIV ) with those found when they used HIV-1 peptides. Yamamoto pointed out that they indeed found a peptide region on FIV that stimulates T cells to kill HIV. She also added that this region found in feline viral peptide is present in several AIDS -like viruses across multiple animal species and that it must be an essential region for the survival of the virus since it cannot mutate.