Researchers at the University of Alberta have discovered a gene that can block certain forms of HIV and may perhaps one day be used to prevent the onset of AIDS.

In lab studies, conducted with scientists at the University of Pennsylvania, researchers at the Edmonton university identified a human gene called TRIM22 that can block HIV infection by preventing the virus from replicating.

When researchers prevented human cells from turning on TRIM22, the natural defence system generated by the body when a foreign invader attacks, the cells could not protect themselves against HIV.

"This means that TRIM22 is an essential part of our body's ability to fight off HIV," Dr. Stephen Barr, a researcher in the department of medical microbiology and immunology at the University of Alberta, said in a release issued Thursday.

Other genes in the TRIM family have also been shown to prevent viruses from replicating. TRIM5a blocks the early replication of HIV-1 while RhTRIM5a blocks late-stage HIV replication.

The scientists are now exploring how this gene can be turned on in people who cannot defend themselves against the virus.

"We hope that our research will lead to the design of new drugs and/or vaccines that can halt the person-to person transmission of HIV and the spread of the virus in the body, thereby blocking the onset of AIDS," said Barr.

He acknowledged that such development could be decades away.

The study was published Thursday in the Public Library of Science journal Pathogens.