Direct Sequencing of Antibodies of the Influenza Immune Response

Abstract The annual epidemics of influenza result in a substantial number of hospitalizations with an estimated to million cases of severe disease and to deaths globally During the th century three major influenza pandemics have occurred with a total mortality of million people Recently new influenza monoclonal antibodies mAbs have been identified that are capable of neutralizing a wide range of viruses In the last eight years several broadly neutralizing stem reactive antibodies have been identified Of these stem antibodies only one recognized all influenza A subtypes however this breadth of recognition was only elicited after in vitro mutagenesis This suggests that an epitope to guide a universal vaccine strategy has yet be defined Stem antibodies could provide universal influenza coverage since they are potentially capable of neutralizing both influenza A and B viruses One strategy to identify neutralizing stem specific antibodies involves immortalized B cells from immunized individuals B cell derived mAbs that cross react with the H and H HA subtypes have been shown to yield high affinity stem specific mAbs that can bind to all influenza A HA subtypes An alternative strategy that doesn t involve B cell cloning starts with an antigen specific population of stem binding polyclonal antibodies pAbs that can then be directly sequenced by proteomic tandem mass spectrometry MS MS These pAbs are a preferred source for mAb discovery since the peripheral antibody population not the peripheral B cell population is representative of the full humoral immune response Direct sequencing of peripheral pAbs can rapidly mine this immune diversity to yield mAbs against novel and unique epitopes Narrative The focus of this proposal is to use a new mass spectrometry based antibody discovery technology to sequence serum antibodies that are components of the human immune response to influenza This is intended to identify antibodies recognizing highly conserved regions of the influenza virus There is a clear unmet need to identify broadly neutralizing influenza antibodies capable of influenza therapy In addition these antibodies will be invaluable in identifying components of the virus that can serve as candidate vaccines to elicit endogenous broadly neutralizing immune responses