HIV discovery could pave the way for fresh treatments

Researchers have identified a new method in which the human immunodeficiency virus, which causes Aids, is able to prevent tetherin –a protein found naturally in human cells – from doing its job of blocking the invaders.

Previous studies have shown how viral protein U (Vpu) helps the spread of HIV in cells by inducing degradation of tetherin.

But a team based in Montreal, Canada, revealed Vpu also interferes with tetherin's ability to travel to the cell's surface, where it would usually trap viruses and prevent them infecting other cells.

Dr Eric Cohen, lead author of the study – published in PLoS Pathogens – said further examination of the process could help scientists find new drugs.

He concluded: "Further characterisation of this mechanism will improve our understanding of host antiviral defences as well as provide new targets for the development of novel anti-HIV drugs."

Dr Marc Oullette, scientific director of the Canadian Institutes of Health Research's Institute of Infection and Immunity, said: "We need to better understand how HIV is transmitted in order to develop new HIV prevention and treatment strategies.

"This is a very important finding by Dr Cohen's research team."

The mechanism deployed by Vpu to assist the spread of HIV identified in the study can be likened to police officers not being able to attend an incident, according to Dr Adriano Boasso, an immunologist at Imperial College London.

He said tetherin is rendered "useless" if it is not able to get to the surface of the cell to perform its barrier function against infection.

"There may be plenty of policemen but if there is a riot at one end of town, there is no point sending them to the other end of town," Dr Boasso said.

"The viral protein prevents the police from leaving the police station, from dealing with the incident.

"Tetherin is prevented from going to the surface of the cell which is where its function is exerted."