US researchers announced today they have found a new immunity gene that may offer a new way to fight back against the Aids virus.
The Aids virus is especially hard to fight because few people develop antibodies to neutralise it, and so far, efforts to make a vaccine against HIV have failed.
But the researchers said the gene Apobec3 helps mice develop antibodies against an HIV-like virus, and they think the same gene in humans could lead to a potent vaccine against the human immunodeficiency virus or HIV.
"This gene is central to HIV biology," Dr. Warner Greene of the Gladstone Institutes at the University of California, San Francisco, said.
In humans, HIV devotes one of its nine genes to disabling Apobec3 proteins, which may help explain why people with HIV rarely make antibodies against the virus, he said.
"If we could prevent HIV from destroying this key pivotal host factor, we might allow HIV-infected patients to develop neutralising antibodies like they do in mice," he said.
"It's a translation from mice to men. That's the challenge now," said Dr Greene, whose study appears in the journal Science.
Dr Green's lab and others have been hunting for the gene in mice that allows them to fight off the Friend virus, a retrovirus similar to HIV.
Working with a team at the National Institute of Allergy and Infectious Diseases, the researchers conducted a series of experiments in which they genetically engineered mice to lack the Apobec3 gene.
"Sure enough, when we knocked out the Apobec3 gene, they lost their ability to recover from Friend virus infection," Dr Greene said.
He said the discovery of Apobec3's role in retroviral immunity is exciting because genes in this region are active in people who resist HIV infection, suggesting they are making effective antibodies against the virus.
Antibodies are key to warding off viral infections, and most vaccines against viral diseases stimulate the body to make antibodies against the target virus.
HIV is a retrovirus, which means it copies bits of its own genetic code into the DNA of the host.
The Aids virus infects an estimated 33 million people globally and has killed about 25 million since the pandemic started in the 1980s. There is no cure but drugs can suppress the virus.
Reuters