A new study recently published in Science suggests researchers found a new way of flue protection, that might work against all types of this viral villain and might foil influenza once and for all. The source of new defense is antibodies from llamas (VHH antibodies)! These furry South American mammals might some day help us fight the flu virus in people.
A team of international scientists led by researchers from California’s Scripps Research Institute transformed a set of harvested VHH into a four-in-one mega protein capable of neutralizing 59 different strains of influenza A and B.
The researchers introduced their powerful protein to mice test subjects in two ways: direct injection and a type of gene therapy that packaged the antibody in a harmless virus before sending it up the animals’ noses.
The scientists tested this synthetic antibody, which comes in the form of a nasal spray, on mice infected with deadly doses of the virus. In all but one case, the engineered antibodies offered complete protection against the flu.
Another route of delivery: gene therapy. The researchers used a benign virus—dubbed AAV—to embed the genetic blueprint of the llama antibodies directly into mouse cells. Once the genetic blueprint embedded itself within the host, the mice’s nose cells began producing the antibodies themselves.
Both methods proved successful the gene therapy avenue could prove particularly beneficial for the elderly and others with weakened immune systems. Rather than relying on these compromised systems to generate antibodies, the “passive transfer” represented by the unique delivery system promises offers its own production mechanism.
“[Our approach] could potentially be used as a preventive treatment from year to year and protect against both seasonal flu as well as potential pandemics, such as bird flu,” said Ian Wilson, a biochemist from Scripps Research who co-led the project.
VHH antibodies are much smaller than human ones, making them better-equipped to reach the nooks and crannies below the hemagglutinin tips, which are areas less likely to mutate than the surface proteins. As a result, the antibodies are more effective at stopping different flu strains in their tracks.
The llama-inspired nasal spray offers both breadth and potency, Scripps structural biologist Ian Wilson tells Science magazine’s Jon Cohen. Compared to the normal flu vaccine, which is largely powerless when faced with unexpected virus strains, the new synthetic antibody could be versatile enough to attack any flu strain that emerges.
Beyond the flu, the idea of using tiny antibodies to attack viruses from new angles opens up the possibility of combatting other diseases with rapid mutation rates. Single-domain antibodies have been tapped as a potential HIV treatment since at least 2010 and again in 2014.
So someday, the world may get through a flu season without the coughing and fevers (and more fatal repercussions as well) … and it might be thanks to llamas.
Influenza viruses consist of genetic material inside a protein envelope. Antibodies match, like puzzle pieces, to the proteins on the outside of a virus, but when the virus mutates the antibodies might no longer match. Image courtesy of CDC/Doug Jones, M.A.