Scientists boost potential of passive immunization against HIV

August 13, 2014
This image shows the atomic level protein structure of the antibody VRC01 (blue and green) binding to HIV (grey and red). The precise site of VRC01-HIV binding (red) is a subset of the area of viral attachment to the primary immune cells HIV infects. Credit: NIAID VRC

Scientists are pursuing injections or intravenous infusions of broadly neutralizing HIV antibodies (bNAbs) as a strategy for preventing HIV infection. This technique, called passive immunization, has been shown to protect monkeys from a monkey form of HIV called simian human immunodeficiency virus, or SHIV. To make passive immunization a widely feasible HIV prevention option for people, scientists want to modify bNAbs such that a modest amount of them is needed only once every few months.

To that end, an NIH-led team of scientists has mutated the powerful anti-HIV bNAb called VRC01 so that, once infused into monkeys, it lasts three times longer in blood than unmutated VRC01, collects in rectal mucosal tissue, and persists there more than twice as long as unmutated VRC01. Concentrating anti-HIV bNAbs at mucosal surfaces of the rectum and vagina, the subject of additional study, is critical for blocking sexual transmission of HIV.

In addition, the scientists found, a low-dose infusion of mutated VRC01 protected monkeys against SHIV infection more effectively than a low-dose infusion of unmutated VRC01.

The mutation works by enhancing VRC01's ability to bind to a cellular protein that prevents the antibody from degrading inside cells and influences how frequently the antibody reaches mucosal surfaces and stays there, the researchers report. This finding may inform antibody-based prevention strategies against not only HIV but also other viruses that invade the body at mucosal surfaces, including rotavirus, poliovirus, norovirus and influenza virus.

Next, the researchers will test infusions of mutated VRC01 in people to learn if it concentrates in mucosal tissues and persists there and in blood for an extended period.

Explore further: Scientists map route for eliciting HIV-neutralizing antibodies

More information: S-Y Ko, et al. Enhanced neonatal Fc receptor function improves protection against primate SHIV infection. Nature, DOI: 10.1038/nature13612 (2014).

Related Stories

Scientists map route for eliciting HIV-neutralizing antibodies

August 11, 2011

Researchers have traced in detail how certain powerful HIV neutralizing antibodies evolve, a finding that generates vital clues to guide the design of a preventive HIV vaccine, according to a study appearing in Science Express ...

New research offers hope for HIV vaccine development

August 13, 2014

In a scientific discovery that has significant implications for HIV vaccine development, collaborators at the Boston University School of Medicine (BUSM) and Duke University School of Medicine have uncovered novel properties ...

Recommended for you

Videos reveal how HIV spreads in real time

October 2, 2015

How retroviruses like HIV spread in their hosts had been unknown—until a Yale team devised a way to watch it actually happen in a living organism. The elaborate and sometimes surprising steps the virus takes to reach and ...

Researchers find proteins that shut down HIV-1

September 30, 2015

A pair of studies by researchers at the University of Massachusetts Medical School, the University of Trento in Italy, and the University of Geneva in Switzerland, point to a promising new anti-retroviral strategy for combating ...

An antibody that can attack HIV in new ways

September 11, 2015

Proteins called broadly neutralizing antibodies (bNAbs) are a promising key to the prevention of infection by HIV, the virus that causes AIDS. bNAbs have been found in blood samples from some HIV patients whose immune systems ...


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.