Location: Virus and Prion ResearchTitle: A monoclonal antibody-based ELISA for differential diagnosis of 2009 pandemic H1N1) Author
Submitted to: Influenza and Other Respiratory Viruses
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/3/2010
Publication Date: 5/1/2011
Citation: Shao, H., Ye, J., Vincent, A.L., Song, H., Hickman, D., Qi, A., Lamichhane, C., Perez, D.R. 2011. A monoclonal antibody-based ELISA for differential diagnosis of 2009 pandemic H1N1. Influenza and Other Respiratory Viruses. 5(Suppl.1):138-142. Interpretive Summary: Influenza A virus causes a respiratory disease in swine similar to that in humans. In addition, it is a component of the multiple pathogen porcine respiratory disease complex in young pigs. Inactivated vaccines work well when pigs are exposed to influenza viruses represented in the vaccine. However, as with the situation in humans, influenza viruses continuously evolve and eventually vaccine efficacy is reduced when new strains no longer cross-react with the immunity induced by the vaccine. This requires continuous monitoring of new viruses and updating of strains used in vaccines. In this report, we developed a monoclonal antibody against the hemagglutinin of the 2009 A/H1N1 pandemic strain and found that it possessed high cross-reactivity and neutralizing activity against multiple H1N1 pandemic strains, but also against classical swine and other H1 strains that belong to clusters circulating among US swine. To our knowledge, this is the first report demonstrating a monoclonal antibody with broad cross-reaction against multiple swine H1 influenza lineages. Based on the high neutralization titer of this antibody and its ability to protect mice against lethal 2009 A/H1N1 pandemic and prototypic swine H1 virus challenge after intranasal administration either before or after virus challenge, this antibody has potential use as an immune therapy against swine-lineage H1 influenza viruses.
Technical Abstract: The swine-origin 2009 pandemic H1N1 virus (pdmH1N1) is genetically related to North American swine H1 influenza viruses and unrelated to human seasonal H1 viruses. Currently, specific diagnosis of pdmH1N1 relies on RT-PCR. In order to develop an assay that does not rely in amplification of the viral genome, a conventional sandwich ELISA for detection of the pdmH1N1 was developed. The sandwich ELISA was based on three monoclonal antibodies (3B2, 5H7, and 12F3) against pdmH1N1. 5H7 and 12F3 were selected as capture antibodies and biotin-conjugated 3B2 was subsequently selected as the detection antibody in the ELISA. The results showed the ELISA had high specificity for pdmH1N1 strains and no reaction with other swine H1 viruses, human seasonal H1N1 or H3N2 viruses, or avian influenza viruses. The limit of detection of the ELISA ranged from 3.2 x 103 to 1.5 x 104 TCID50 /ml. When the ELISA was used to detect viruses in nasal wash samples from infected ferrets, it showed 90.1% sensitivity and 100% specificity compared to the "gold standard" - virus isolation. Our studies highlight a convenient assay for specific diagnosis of the 2009 pandemic H1N1-like viruses.