Key Structure of Infection Protein Found For HIV Vaccine

Two new researches show, how US researchers managed to discover the comprehensive structure of a protein that performs, a key part in, HIV infection. The discoveries provide the kind of in-depth knowing that has been lost in the development of effective vaccines against the AIDS virus.


Using protein engineering and two distinct cutting-edge structural biology imaging method, collaborating groups from The Scripps Research Institute and Weill Cornell Medical College have unveiled a comprehensive atomic structure of the HIV envelope trimer identified as Env.

The novel finding is reported in two researches, both released online in Science this week.

None of the HIV vaccines examined so far has come near to giving enough protection, a failure that is mostly due to the difficulties posed by Env. Env is a three-part protein (a trimer) identified on the surface of HIV that is vital to understanding how the virus gets into human cells to trigger infection.

Knowing Env

Env has developed highly efficient ways of preventing attack by the immune system. For example, it regularly mutates its exterior regions, and it also coats its surfaces with really slippery sugar molecules known as glycans.

The more researchers know about Env and its structure, the greater the chances of building successful vaccines. It has been challenging to get atomic-level resolution images of the Env protein due to the fact its structure is complicated and sensitive – but now new methods have now made this feasible.

Initially, to capture the image, the groups designed a more constant version of the protein, as one of the senior authors and an assistant professor in TSRI’s describes:

“It is likely to fall apart, for instance, even when it is on the surface of the virus, so to research it we have to engineer it, to be more constant.”

Then, having stabilized the Env trimer, utilizing cryo-electron microscopy and X-ray crystallography, the research were capable to uncover its structure and also how it puts together and engages with HIV antibodies.

One element of the discovery that will be of great assist to vaccine developers is understanding the precise information of the sites where HIV antibodies can bind to the virus – so they can mimic these viral “epitopes” with the vaccine.

Another senior author, from the Hansen Professor of Structural Biology at TSRI, states that:

“Most of the before structural research of this envelope complex targeted on individual sub-units, but we’ve required the structure of the full complex to appropriately define the sites of weaknesses that could be targeted, for example with a vaccine.”