Cats May be the Key to Developing Effective Human HIV Vaccine

A team of international scientists have made a major breakthrough toward developing the human AIDS vaccine. The researchers suggest cats may be the key to the vaccine.

This surprising discovery made by scientists at the University of Florida and University of California, San Francisco, offers strong clues for a  solution to HIV infection,  a worldwide epidemic. According to the scientists, blood from HIV infected human shows an immune response against a cat AIDS virus protein

"One major reason why there has been no successful HIV vaccine to date is that we do not know which parts of HIV to combine to produce the most effective vaccine," Janet Yamamoto, Ph.D., a professor of retroviral immunology at the University of Florida College of Veterinary Medicine and corresponding author on the study, said in a press statement.

The researchers are mainly focusing on developing a T cell (a type of white blood cell that plays an essential role in cell mediated immunity) based vaccine against HIV that generates a cellular immune response in those who test positive for HIV.  T-cell peptides are the tiny pieces of protein that trigger the T-cells present in to the body to identify the viral peptides present in the infected cells and start antiviral activity against these cells.

But Yamamoto claims that not all peptides present on the HIV protein can function as vaccine components.

In the human body certain peptides trigger an immune response that either boots out HIV infection or does not have any effect. Whereas other peptides carry an anti-HIV activity that vanishes when the virus undergoes changes or mutates in order to avoid immunity. Therefore, in this new study, the researchers are looking for such viral peptides within the feline AIDS virus that can induce anti HIV T-cell activities and which does not mutate.

Prior to this finding, several scientists have worked on the possible way to develop a vaccine against this disease. But none of the studies could develop a commercially viable vaccine.

This study is different as the researchers have discovered that certain peptides of the cat AIDS virus can function better at producing human T-cells that battle against HIV.

They initially separated T-cells from HIV positive subjects and then incubated these cells with various peptides that are crucial for the survival of both humans and feline AIDS viruses. The researchers then compared the reactions received with FIV peptides to the one they received using HIV-1 peptides.

"We found that one particular peptide region on FIV activated the patients' T-cells to kill the HIV," Yamamoto said. This feline viral region identified by human cells appears to be evolutionarily conserved - it is present in multiple AIDS-like viruses across animal species," she added. "That means it must be a region so essential that it cannot mutate for the survival of the virus."

From this study, the researchers emphasize that in order to trace regions of human AIDS virus, feline AIDS virus can be used to develop a vaccine strategy for HIV.

"We want to stress that our findings do not mean that the feline AIDS virus infects humans, but rather that the cat virus resembles the human virus sufficiently so that this cross-reaction can be observed," said Jay A. Levy, M.D., a professor of medicine at the University of California, San Francisco and a collaborator in the study.

The findings are presented in the journal of Virology.