Imitating monkey's 'jumping genes' could lead to new treatments for HIV

Feb 18, 2008

UCL (University College London) scientists have taken a significant step in understanding how retroviruses such as HIV can move between species and the biological mechanisms behind the ‘jumping genes’ which make some monkeys immune. They will now use this knowledge to develop a gene therapy treatment for HIV/AIDS in humans.

The international team of researchers, coordinated by Professor Greg Towers, UCL Infection and Immunity, and funded by the Wellcome Trust, have identified a combination of genes in a species of monkey that protects against retroviruses – a particularly opportunistic family of viruses that can integrate into the host’s genome and replicate as part of the cell’s DNA. The team’s findings are published today in Proceedings of the National Academy of Sciences.

Professor Towers explained: “HIV causes AIDS and affects around 40 million people worldwide. Research has shown that HIV entered the human population from a chimpanzee retrovirus called SIV early in the 20th century. In order for a virus to successfully cross the species barrier and jump into a new species, it first has to bypass the new host's innate immune system, mediated by a combination of genes and proteins. One such gene, called TRIM5, has been shown to protect certain species from retroviruses – but unfortunately the human TRIM5 gene does not protect against HIV infection.”

The team found that a species of Asian monkey called Rhesus Macaques have a sophisticated ‘antiviral arsenal’ that can protect them against retroviruses. By closely examining TRIM5 in this species, they demonstrate that in some monkeys another gene called Cyclophilin has been joined to the TRIM5 gene, generating a TRIMCyp fusion.

Dr Sam Wilson, the paper’s first author, said: “Cyclophilin is very good at grabbing viruses as they enter cells. By fusing Cyclophilin to TRIM5, a gene is made that is good at grabbing viruses and good at destroying them.
This is the second time that this fusion has been identified – a TRIMCyp gene also exists in South American Owl Monkeys and, until now, this was thought to be an evolutionary one-off.

“This new research shows that a TRIMCyp has evolved independently in two separate species – it's like lightening has struck twice. It’s a remarkable example of convergent evolution, where organisms independently evolve similar traits as a result of having to adapt to similar environments. It also highlights the evolutionary selection pressure that viruses like HIV can apply.”

Professor Greg Towers explained further: “The discovery is a compelling example of how ‘jumping genes’ can shuffle an organism’s genetic makeup, generating useful new genes, and it is an exciting possibility for novel treatments for HIV/AIDS.

“About 25 per cent of Rhesus Macaques have the TRIM5 and a TRIMCyp gene, greatly expanding their antiviral arsenal. The others have an immunity, based around TRIM5, that protects them against a different combination of viruses. The gene seems to be evolving to protect the individual species from a range of different virus sequences.”

Professor Towers and his team now aim to develop humanised TRIMCyp that blocks HIV infection by artificially fusing human Cyclophilin and human TRIM5. Professor Towers said: “We can then introduce the TRIMCyp into stem cells, using gene therapy technologies, and the stem cells could repopulate the patient with blood cells that are immune to HIV. This work, already underway, could offer a real possibility of novel treatments for HIV/AIDS."

Source: University College London

Explore further: Animal study provides first evidence that gel can prevent multiple virus transmission in vagina/rectum

add to favorites email to friend print save as pdf

Related Stories

Researchers unveil new monkey model for HIV

Mar 02, 2009

By altering just one gene in HIV-1, scientists have succeeded in infecting pig-tailed macaque monkeys with a human version of the virus that has until now been impossible to study directly in animals. The new strain of HIV ...

Monkey gene that blocks AIDS viruses evolved more than once

Feb 29, 2008

Researchers at Harvard Medical School have identified a gene in Asian monkeys that may have evolved as a defense against lentiviruses, the group of viruses that includes HIV. The study, published February 29 in the open-access ...

Recommended for you

HIV+ women respond well to HPV vaccine

Apr 16, 2014

HIV-positive women respond well to a vaccine against the human papillomavirus (HPV), even when their immune system is struggling, according to newly published results of an international clinical trial. The study's findings ...

User comments : 0

More news stories

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Study says we're over the hill at 24

(Medical Xpress)—It's a hard pill to swallow, but if you're over 24 years of age you've already reached your peak in terms of your cognitive motor performance, according to a new Simon Fraser University study.

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.