FDA research leads to new insights into antibody repertoire of patients with avian influenza

An analysis of blood samples from patients recovering from H5N1 avian influenza has, for the first time, allowed researchers to identify the complete antibody repertoire in patients who have contracted the virus.

Experts say these data may be an important advancement and may help contribute to a vaccine against H5N1 or help to improve H5N1-specific surveillance tools.

The study, conducted by a team of researchers from the FDA, was designed to help explain how a person’s immune system is affected by avian influenza.

The researchers used genetically-modified viruses to create a library of fragments representing all of the proteins found in the H5N1 virus. These fragments were then mixed with antibodies from five Vietnamese patients recovering from H5N1 infection to determine which fragments attracted the patient’s antibodies.

The results showed that the protein PB1-F2 is a potentially potent target for attack by immune systems to stop the spread of the virus. The researchers said PB1-F2 may contribute significantly to the virus’s ability to cause disease.

“We believe this is the first evidence of the human immune system reacting this strongly against PB1-F2,” Hana Golding, PhD, chief of the FDA’s Center for Biologics Evaluation and Research’s Laboratory of Retrovirus Research and one of the study’s researchers, said in a press release. “This is an indication that it may be a good target for a drug or vaccine.”

Khurana S. PLoS Med. 2009; doi:10.1371/journal.pmed.1000049.