Researchers at the Technion–Israel Institute of Technology in Haifa have uncovered the mechanism that enables Feline Immunodeficiency Virus, or FIV, proteins to become drug-resistant—a phenomenon not yet observed in the AIDS-causing HIV-1 virus, which affects millions of people worldwide.

While FIV does not infect humans, it is widely researched to benefit cats. More important are its parallels with the AIDS virus.

The virus is transmitted between male street cats, primarily via saliva. Like in humans, the virus involves immune impairment and the inability to fight off infections, diseases and cancer. Because highly similar viruses cause FIV and HIV, researchers hope that the findings could lead to the development of anti-HIV drugs that could preempt future strains of drug-resistant AIDS viruses.

This phenomenon of FIV-protein drug resistance, which inhibits the same protein in HIV-1, puzzled scientists until now.

According to an American Technion Society press release, Assistant Professor Akram Alian and Dr. Meytal Galilee from the Technion biology faculty have shown the 3D structure of this protein in the FIV and used it to uncover the mechanistic basis of viral resistance to anti-reverse transcriptase drugs.

Their findings, published recently in PLOS Pathogens, show that the FIV protein forms a closed pocket that blocks the drugs from effective binding.