Scientists hope to be able develop a vaccine to prevent HIV after capturing the most detailed picture yet of a key Aids protein
A vaccine to prevent HIV could be on the horizon after a major breakthrough in understanding the structure of disease, a new study reveals.
Scientists have determined the first atomic level structure of HIV’s ‘envelope’ protein, which they say is of great value for medical science.
The findings provide the most detailed picture yet of the Aids-causing virus’s complex envelope, which help it enter human cells.
The understanding could help find parts of the virus which future injections could mimic to elicit a protective immune response.
Around 34 million people are infected with HIV and although drugs are used to manage many infections, there is no vaccine that can prevent new infections with the aim of ridding the world of the virus.
None of the HIV vaccines tested so far has come close to providing adequate protection thanks to the challenges posed by the envelope protein, known as Env.
Env’s structure is so complex and delicate, scientists have found it difficult to get the protein in a form that is suitable for the atomic-resolution imaging necessary to understand it.
Professor Andrew Ward, of The Scripps Research Institute (TSRI), explained: “It tends to fall apart, for example, even when it’s on the surface of the virus, so to study it we have to engineer it to be more stable.”
In the study, researchers created a version of the Env three-component structure that has the stability and other properties needed for atomic-resolution imaging, but that retains virtually all the structures found on Env.
Using cutting-edge imaging methods, electron microscopy and X-ray crystallography the researchers were able to look at the new Env.
It was the first ever study of Env, and both methods resolved the structure to a finer level of detail than has been reported before.
The study for Science Express revealed how Env assembles and undergoes shape changes during infection, and showed how it compares to envelope proteins on other dangerous viruses – such as flu and Ebola.
Professor Ian Wilson, of TSRI, said: “Most of the prior structural studies of this envelope complex focused on individual subunits; but we’ve needed the structure of the full complex to properly define the sites of vulnerability that could be targeted, for example with a vaccine.”
Professor John Moore, of Cornell University who helped with the study, said: “Now we all need to harness this new knowledge to design and test next-generation trimers and see if we can induce the broadly active neutralising antibodies an effective vaccine is going to need.”