Potent antibodies neutralize HIV and could offer new therapy, study finds

November 7, 2012, Rockefeller University
Potent antibodies neutralize HIV and could offer new therapy, study finds
Mice with HIV that were given a combination of five potent antibodies were able to effectively suppress the virus for a 60-day period, longer than current antiretroviral drugs which require daily application. The antibodies target HIV-1’s surface protein gp160, which is notorious for evading the immune system’s attacks by constantly mutating.

(Medical Xpress)—Having HIV/AIDS is no longer a death sentence, but it's still a lifelong illness that requires an expensive daily cocktail of drugs—and it means tolerating those drugs' side effects and running the risk of resistance. Researchers at The Rockefeller University may have found something better: they've shown that a therapeutic approach harnessing proteins from the human immune system can suppress the virus in mice without the need for daily application and could one day be used in humans to treat the disease.

Florian Klein and colleagues in Michel Nussenzweig's Laboratory of found that a combination of five different antibodies—proteins the uses to fight infection—effectively suppressed HIV-1 replication and kept the virus at bay for a 60 day period after termination of therapy thanks to their longer half-life, while current require daily intake.

These especially potent antibodies were only recently discovered, some of them by several of Klein's colleagues in the Nussenzweig laboratory. Called broadly-, they were identified and cloned from HIV-infected patients whose immune systems showed an unusually high ability to neutralize HIV. In recent years the potent antibodies were found to prevent HIV from infecting non-human primates, demonstrating the possibility for a vaccine in humans. But they were thought to have little or no effect on established infections.

"Antibodies had been written off as a treatment for HIV/AIDS because previous studies showed only a limited effect on controlling the virus," says Klein. "But that was before these more potent antibodies were discovered. We wanted to readdress this question using these new tools."

HIV-1 is notorious for evading the immune system's attacks by constantly mutating, but the new antibodies are able to throw a wrench in that strategy. The key is in the combination. The antibodies target HIV-1's gp160, a large molecule that forms a spike that seeks out host cells and attaches to them. One antibody alone wasn't enough to quell the virus; neither was a mix of three. But five of them in unison proved too complicated for gp160 to mutate its way out of.

The researchers used "humanized" mice for the study, provided by Alexander Ploss in the Laboratory of Virology and Infectious Disease, because normal mice don't have the right receptors to be infected with HIV-1.

"Although HIV-1 infection in humanized mice differs in many important aspects from infection in humans, the results are encouraging to investigate these antibodies in clinical trials," says Klein. "It also may be that a combination of antibodies and the already established antiretroviral therapy is more efficacious than either alone," says Klein.

"If this could be used as a treatment one day, it is conceivable that patients would only need to take traditional drugs until the virus is controlled, and then receive antibodies every two to three months to maintain that control. We're eager to explore if a benefit in HIV-1-treatment can be achieved in humans."

Explore further: Researchers discuss challenges to developing broadly protective HIV vaccines

More information: Klein, F. et al., HIV therapy by a combination of broadly neutralizing antibodies in humanized mice. Nature online, October 24, 2012. www.nature.com/nature/journal/ … abs/nature11604.html

Related Stories

Researchers discuss challenges to developing broadly protective HIV vaccines

September 7, 2011
The human body can produce powerful antibodies that shield cells in the laboratory against infection by an array of HIV strains. In people, however, recent research shows that these broadly neutralizing antibodies are not ...

Scientists identify broad and potent HIV antibodies that mimic CD4 binding

July 20, 2011
In a finding that may be good news for scientists developing HIV vaccines and therapies, a team of researchers at The Rockefeller University and the Howard Hughes Medical Institute have found a way to investigate the broadly ...

Neutralizing HIV

July 18, 2011
Each time a virus invades a healthy individual, antibodies created by the body fight to fend off the intruders. For some viruses, like HIV, the antibodies are very specific and are generated too slowly to combat the rapidly ...

Recommended for you

Genomics reveals key macrophages' involvement in systemic sclerosis

January 18, 2018
A new international study has made an important discovery about the key role of macrophages, a type of immune cell, in systemic sclerosis (SSc), a chronic autoimmune disease which currently has no cure.

First vaccine developed against grass pollen allergy

January 18, 2018
Around 400 million people worldwide suffer in some form or other from a grass pollen allergy (rhinitis), with the usual symptoms of runny nose, cough and severe breathing problems. In collaboration with the Viennese firm ...

Researchers discover key driver of atopic dermatitis

January 17, 2018
Severe eczema, also known as atopic dermatitis, is a chronic inflammatory skin condition that is driven by an allergic reaction. In their latest study, researchers at La Jolla Institute reveal an important player that promotes ...

Who might benefit from immunotherapy? New study suggests possible marker

January 16, 2018
While immunotherapy has made a big impact on cancer treatment, the fact remains that only about a quarter of patients respond to these treatments.

Researchers identify new way to unmask melanoma cells to the immune system

January 16, 2018
system, which enables these deadly skin cancers to grow and spread.

How the immune system's key organ regenerates itself

January 15, 2018
With advances in cancer immunotherapy splashing across headlines, the immune system's powerful cancer assassins—T cells—have become dinner-table conversation. But hiding in plain sight behind that "T" is the organ from ...

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.