"The purpose of the database is to provide a catalog of molecules and structures that scientists around the world can quickly access and use to understand the immune response to a variety of epitopes, or methodically predict responses to as-yet untested targets," says Alessandro Sette, Ph.D., who heads the Vaccine Discovery division at LIAI and is the lead investigator on the project.
For the current study, Dr. Sette and his colleagues examined 600 different epitopes from 58 different strains of influenza A virus. One of their main goals was to determine how conserved, or similar, epitopes are between different strains of bird and human influenza viruses. Knowing this is important because the virus rapidly mutates and can swap gene segments between strains, which could increase the ability of an avian virus to be transmissible to humans.
In addition, only a handful of the epitopes are known to be associated with protective immunity. Most of the influenza virus epitopes in the database are those recognized by a type of immune cell known as a T cell; far fewer are recognized by B cells, a type of white blood cell that produces infection-fighting antibodies. Antibodies induced by seasonal and pandemic flu viruses or vaccines are a major component of immunity that protects against these viruses.
Strains of influenza virus can vary enough in their neutralizing B cell epitopes that a vaccine against one strain may not protect against another strain. But if epitopes are conserved between virus strains, the immunity a person has developed towards one strain might provide at least some protection against the other strain.