Tethered antibodies offer broad Flu protection in mice

Tethering four antibodies together may offer protection against all types of influenza virus known to infect humans, according to a study published recently in Science. Key to the study was creating a multidomain antibody. For this purpose, antibodies from llamas that had been challenged with vaccines containing several types of influenza viruses were used. Llamas produce unique antibodies that are smaller and simpler than those found in humans and fit into smaller and more recessed binding sites, allowing them to be linked together.

Two llama antibodies against influenza A and two against influenza B were tethered together to create the multidomain antibody. X-ray and electron microscopy were then used to ascertain where the antibody was binding to influenza proteins, revealing that the antibody was able to target several vulnerable sites on influenza A and B. This indicates that the antibody could have the ability to protect against all circulating strains that affect humans and any potential new subtypes caused by mutation. The researchers then turned their attention to the question of how to deliver the antibodies. Rather than using a traditional vaccine, the researchers used a viral vector that could deliver an engineered gene instructing cells to start expressing a producing protein comprised of fragments from all four llama antibodies. The viral vector was administered to mice via a nasal spray. After receiving treatment, the mice rapidly began producing the protective antibodies in their upper respiratory tract. Continuous protection against a variety of influenza strains was observed.

While the results of this study are promising, further research beyond the preclinical stage is required to determine if this strategy can be employed in humans. Read the article in Science.

This article originally appeared on Biocompare.