Scientists find surprising trait in anti-HIV antibodies

November 17, 2015
Authors of the new paper included (left to right) James Voss, Raiees Andrabi, Dennis Burton, Bryan Briney and Chi-Hui Liang. Credit: Cindy Brauer, The Scripps Research Institute

Scientists at The Scripps Research Institute (TSRI) have new weapons in the fight against HIV.

Their new study, published Nov. 17, 2015 as the cover article of the journal Immunity, describes four prototype that target a specific weak spot on the virus. Guided by these antibodies, the researchers then mimicked the molecular structure of a protein on HIV when designing their own potential HIV candidate.

"This study is an example of how we can learn from natural infection and translate that information into ," said TSRI Research Associate Raiees Andrabi. "This is an important advance in the field of antibody-based HIV vaccine development."

Andrabi served as first author of the study, working in the lab of senior author TSRI Professor Dennis R. Burton, who is also scientific director of the International AIDS Vaccine Initiative (IAVI) Neutralizing Antibody Center and of the National Institutes of Health's Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery (CHAVI-ID) at TSRI.

Surprising New Antibodies

The findings build on the success of several recent TSRI studies showing that, with prompting, the can develop antibodies to neutralize many strains of HIV.

In the new study, the researchers carried out a series of experiments involving virus modifications, protein and antibody engineering. They found that four antibodies targeted a single spot on HIV's surface called the V2 apex. This was significant because the V2 apex could be recognized by these antibodies on about 90 percent of known HIV strains—and even related strains that infect other species. A vaccine targeting this region could protect against many forms of the virus.

"This region helps stabilize the virus, so it's an important area to target if you want to neutralize HIV," said Andrabi.

Investigating further, the researchers noticed that two of the four antibodies had an unusual feature that could prove important in vaccine design.

The immune system usually begins its fight against infection by activating immune B cells that express 'germline' forms of antibodies, on their surface, to bind invading pathogens. Germline antibodies rarely bind viruses very effectively themselves; instead, they are precursors for more developed antibodies, which mutate and hone their response to the invader.

Yet in the new study, two of the antibodies did not need to mutate to bind with the V2 apex; instead, these antibodies used part of their basic germline structure, encoded by non-mutated genes. This means any patient with HIV should, in theory, have the ability to kick-start the right immune response.

Unfortunately, the immune system seems to naturally produce only a small number of these HIV-neutralizing germline antibodies. To generate an immune response that would favor these antibodies, it was critical for the scientists to find the right proteins in HIV that the antibodies could recognize and bind to.

In the new study, the researchers succeeded in mimicking a structure on HIV called the native HIV coat protein. This let them design proteins that do indeed bind well to the germline antibodies and hopefully start a useful . The next step will be to test the vaccine candidates in animal models.

Explore further: Researchers model alternate ideas for an HIV vaccine

Related Stories

Researchers model alternate ideas for an HIV vaccine

September 18, 2015
Scientists at Los Alamos National Laboratory have created a computational model that could change the way that researchers look at possibilities for an HIV-1 vaccine.

New study has important implications for the design of a protective HIV vaccine

October 13, 2015
A PhD student from the University of the Witwatersrand today, 12 October 2015, published a study in the prestigious journal, Nature Medicine, describing how the changing viral swarm in an HIV infected person can drive the ...

HVTN 505 vaccine induced antibodies nonspecific for HIV

July 30, 2015
A study by researchers at the National Institute of Allergy and Infectious Diseases and Duke University helps explain why the candidate vaccine used in the HVTN 505 clinical trial was not protective against HIV infection ...

Immune responses provide clues for HIV vaccine development

October 21, 2015
Recent research has yielded new information about immune responses associated with—and potentially responsible for—protection from HIV infection, providing leads for new strategies to develop an HIV vaccine. Results from ...

Scientists shows AIDS vaccine candidate successfully 'primes' immune system

June 18, 2015
New research led by scientists at The Scripps Research Institute (TSRI), International AIDS Vaccine Initiative (IAVI) and The Rockefeller University shows in mice that an experimental vaccine candidate designed at TSRI can ...

Scientists discover HIV antibody that binds to novel target on virus

September 3, 2014
An NIH-led team of scientists has discovered a new vulnerability in the armor of HIV that a vaccine, other preventive regimen or treatment could exploit. The site straddles two proteins, gp41 and gp120, that jut out of the ...

Recommended for you

Scientists find where HIV 'hides' to evade detection by the immune system

October 19, 2017
In a decades-long game of hide and seek, scientists from Sydney's Westmead Institute for Medical Research have confirmed for the very first time the specific immune memory T-cells where infectious HIV 'hides' in the human ...

National roll-out of PrEP HIV prevention drug would be cost-effective

October 18, 2017
Providing pre-exposure prophylaxis (PrEP) medication to men who have sex with men who are at high risk of HIV infection (equivalent to less than 5% of men who have sex with men at any point in time) in England would be cost-effective, ...

Regulatory T cells harbor HIV/SIV virus during antiviral drug treatment

October 17, 2017
Scientists at Yerkes National Primate Research Center, Emory University have identified an additional part of the HIV reservoir, immune cells that survive and harbor the virus despite long-term treatment with antiviral drugs.

New research opens the door to 'functional cure' for HIV

October 17, 2017
In findings that open the door to a completely different approach to curing HIV infections, scientists from the Florida campus of The Scripps Research Institute (TSRI) have for the first time shown that a novel compound effectively ...

Researchers create molecule that could 'kick and kill' HIV

October 5, 2017
Current anti-AIDS drugs are highly effective at making HIV undetectable and allowing people with the virus to live longer, healthier lives. The treatments, a class of medications called antiretroviral therapy, also greatly ...

A sixth of new HIV patients in Europe 50 or older: study

September 27, 2017
People aged 50 and older comprise a growing percentage of HIV patients in Europe, accounting for one in six new cases in 2015, researchers said Wednesday.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.