The team, led by Sea Lane Biotechnologies, collected the samples from the bone marrow of survivors of the 2005/2006 outbreak in Turkey. They then processed the samples to isolate and amplify the monoclonal antibodies present in the sample. The resulting libraries of the antibodies found in each survivor charted the complete immune response of the patient to the disease. This allowed the scientists to see how combinations of antibodies, rather than a single antibody, successfully combated the disease.
"The term library is a good metaphor," says Richard Lerner, president of the Scripps Research Institute, who collaborated on the project. "The resulting collections allow scientists to check out any antibody [in the sample] they like."
So far, the antibody libraries have yielded more than 300 monoclonal antibodies that target bird flu antigens. According to Lerner, it is very easy to reproduce exact replicas of these antibodies at high volumes for a ready made treatment to the disease. "They're pretty much ready to go," he says. However, they would first need to be tested on animals, to prove that they are effective on a range of subjects.
The libraries also revealed exciting leads for artificially designed vaccines. Many of the antibodies were found to target more than one strain of bird flu, and three were found to target common flu as well. The scientists hope to study the antibodies to find which parts of the different viruses the antibodies target, with the hope of finding a common weak spot amongst all the different strains. A drug designed to target this weak spot would cure many different types of flu, which would be a huge improvement on the current treatments, which are much more strain-specific.
"These antibodies may be used to identify cross-reactive epitopes on the hemagglutinin protein of an influenza virus," said Peter Palese from the Mount Sinai School of Medicine, another collaborator on the project. "Identification of such epitopes may allow the rational design of vaccines with cross-subtype neutralizing activity. Such vaccines would constitute a major advance on current technology, and would be a first step towards the design of a universal influenza vaccine."
The research, published in the Proceedings of the National Academy of Sciences, could suggest the route for other research groups to proceed with their work.
"Our libraries create a roadmap for improving the efficacy and/or specificity of therapeutic influenza antibodies," said Arun Kashyap, director of influenza and antibody libraries for Sea Lane. "As a result, we might be able to engineer the best features of different antibodies into a single antibody that may not only treat contemporary strains of influenza, but also future influenza strains which normally would escape through simple mutations."