A mechanism that may serve as the foundation for resistance of feline immunodeficiency virus (FIV), the virus that causes “feline AIDS,” has been discovered by a team of researchers from the Technion – Israel Institute of Technology in Haifa.

FIV is caused by viruses very similar to the AIDS-causing HIV-1 virus, which currently affects millions of humans. The feline AIDS disease is transmitted between cats, primarily via saliva, and causes a breakdown of the immune system along with the inability to fight off infections, diseases and development of cancer. The disease typically affects male street cats, which tend to fight and bite one another.

Though immunodeficiency in cats does not infect humans, it is a popular subject of research due to its ability to benefit cats and its many parallels with the AIDS virus.

Assistant Prof. Akram Alian and Meytal Galilee from the Technion Faculty of Biology recently published their findings in PLOS Pathogens.

The study uncovers how FIV proteins can undergo minor modifications that enable them to develop resistance to drugs, while preserving protein function, a phenomenon not yet observed in HIV-1. Although FIV and HIV are highly similar, the FIV protein is resistant to drugs that can inhibit the same protein in HIV-1, which has puzzled scientists until now.

The study also revealed that the FIV protein forms a closed pocket that blocks the drugs from effective binding.

“We hope that our discoveries will pave the way toward the development of drugs that will ‘break into’ this pocket, thereby enabling the drugs to inhibit FIV from multiplying,” said Alian. “Of course, due to the parallels between FIV and HIV, we assume that the discovery will also assist in combating AIDS.”