STUDY: How Mutated Antibodies Could Eliminate HIV in the Body
The problem with many HIV-neutralizing antibodies is that they can take 10 to 15 years to mature inside the body and aren’t effective at fighting HIV until then. That’s too long to wait for vaccine use.
But now scientists at Scripps have discovered a way to make an antibody found in the blood of an HIV-positive person in China grow much faster. Simply by feeding this antibody Cheerios (as a matter of phrase) it can produce useful, HIV-fighting antibodies that can be hard at work in just a year or two.
What does it all mean? “This makes the idea of a universal vaccine a real possibility,” according to The Scripps Research Institute news release.
The groundbreaking research serves as the cover story today of the journal Immunity.
“This is actually the first example of how we can go back to the really early stage to see how this antibody lineage was born and can develop,” said TSRI biologist Jiang Zhu, who served as senior co-author of the study.
The Chinese patient from which this newly discovered antibody came from is an “elite controller,” meaning the patient had managed to create antibodies with some ability to fight HIV. The patient was among the top five percent of neutralizers assessed after Chinese scientists screened hundreds of patients.
This marks the first time that a VRC01-like antibody has come from a person with Asian descent. The others have come from African or Caucasian patients. “This means people with different genetic backgrounds may benefit from a vaccine that harnesses a person’s ability to make VRC01s,” Scripps explained in the news release.
“This could be important for developing a universal HIV vaccine,” Zhu said.
The antibody has a similar genetic makeup as other members of the VRC01 class of antibodies, which are known as “broadly neutralizing.” That means they are effective against many strains of the ever changing virus, which is what’s needed for an effective HIV vaccine.
However, this antibody lacked one of the key structural traits of other VRC01 antibodies. “It represented a middle stage in the evolution of this class of HIV killers,” Scripps reported. Zhu called the antibody a “teenager” and said it offers scientists clues as to how to prompt the immune system to effectively target HIV.
The researchers began study this patient’s antibody in 2006, when he described it as a “toddler.”
“Each sample showed the antibody in a different stage of development, giving researchers a possible guide for how to elicit these antibodies with a vaccine,” Scripps reported. “Zhu and his colleagues were surprised to find that the antibody evolved rapidly between 2006 and 2008, gaining many of the traits it would need to fight HIV.”
Scripps reported that the scientists spotted a hurdle that will need to be overcome when creating their own antibodies. “The teenage VRC01 has a slightly longer amino acid chain at one site than the mature version, and this chain clashes with part of the glycoprotein shield (gp120) on HIV and prevents the antibody from effectively neutralizing the virus.”
But the researchers managed to tweak the immature antibody to make it into a broadly neutralizing antibody. “As long as you have some of those VRC01 signatures, a teenage-stage antibody can become a killer for HIV,” said Zhu.