Cows can produce antibodies that neutralize HIV
Cows can produce a type of antibodies that have been shown in laboratories to stop 96% of HIV strains from infecting human cells, according to a new study in Nature.
Why it matters: Scientists have been trying to elicit these so-called "broadly neutralizing antibodies" (bNAbs) by immunization for decades in hopes of creating a vaccine that can provide protection from HIV. The bNAbs made by the cows, which don't contract HIV, can be studied to understand how they might potentially be elicited in humans via a vaccine. "The study … doesn't tell us how to make a vaccine for HIV in people, but it does tell us how the virus evades the human immune response," John Mascola, director of vaccine research at NIAID, told STAT News.
Still TBD: We've "shown in a test tube that the antibodies can neutralize the virus," but not in a real human model, Anthony Fauci, the director of NIAID at the NIH, told Axios. He added it would be "pretty easy" for scientists to "modify [the bNAbs] so that they'd be compatible to administer them to humans" for short-term prevention or treatment. It is unclear whether effective antibodies can be produced at a scale and rate that works for widespread distribution.
Can't humans develop these antibodies on their own? It's true that 10-20% of humans living with HIV naturally develop bNAbs — but not until years after getting infected, rendering most of them irrelevant since the virus would likely have already evolved, Fauci said.
- The bovine advantage: Cows' immune systems seem to have powerful bNAbs to protect their multiple stomach chambers. Plus, the researchers noted that cows developed these antibodies in a short period of time (4 weeks v. 3-5 years in humans).
How they did it: The researchers infected four cows with a protein that mimics the outside of the HIV virus and the cows' immune systems rapidly created antibodies in response. They were then able to isolate the antibodies and, in the laboratory, they blocked multiple strains of HIV from infecting cells.