Development of competitive ELISA for detection of N1 and N2 antibodies against influenza virus

Abstract

Influenza A virus (IAV) surveillance in animals and humans are important to monitor the spread of circulating strains and detect emergence of new strains. The neuraminidase (NA) subtype is restricted to neuraminidase inhibition and virus neutralization assays. The presence of NA1 and NA2 antibodies is of major interest because these subtypes of IAV are the most common circulating subtypes among avian, swine and human. To develop assays that can be used in automatic settings the NA1 of a highly pathogenic avian influenza (HPAI) virus strain A/CK/Indonesia/PA7/2003 (H5N1) and NA2 of the triple reassortant A/turkey/OH/313053/04 (H3N2) were previously cloned and expressed in a baculovirus system. Monoclonal antibodies (MAbs) against baculavirus expressed N1 and N2 recombinant antigen were generated. The purified N1 and N2 MAbs were used to develop competitive ELISAs to detect N1 or N2 antibodies in different species. Only the N1 monoclonal antibodies were successfully used in the establishment of competitive ELISA systems.