6th Clinical Microbiology Conference

Biography

Biography: Malgorzata G Norton

Abstract

Avian influenza continues to be a public health problem.  Vaccination may prevent or ameliorate the disease; however, it may not always be feasible to match the timing of the vaccine administration to the time of exposure, or additional therapeutics may be needed in the case of severe disease. Passive antibody therapy with polyclonal anti-influenza immune (hyperimmune) globulins may be an effective complementary therapy. Hyperimmune globulin therapy is already in place for several infectious agents and an anti-H5N1 Equine F(ab’)2 product has recently obtained EMA Orphan Drug status. In order to screen individual plasma donations for high neutralizing titers to pool into a hyperimmune product, a fast and reliable neutralizing antibody assay is needed. Currently, the hemagluttination inhibition (HAI) and microneutralization (MN) assays are used to detect neutralizing antibodies against Influenza viruses; however, each assay requires the use of live virus. We developed a Surface Plasmon Resonance (SPR) assay to measure anti-H5 HA antibodies for neutralizing activity which has no requirement for live virus. Briefly, biotinylated multimeric glycans containing sialic acid moieties were captured on a streptavidin-coated surface, acting as a model for influenza cell-surface receptors. Multimeric H5 HA recombinant protein micelles preincubated with a dilution sequence of antibodies or serum were then injected over the glycans.  The results of the antibody dilutions preincubated with H5 HA were compared to H5 HA only, and an IC50 was calculated. Using the IC50 measurement we could rank the mAb and polyclonal sera in order of neutralizing activity. The SPR assay may also be adapted to measure the neutralizing antibody against other infectious agents where the host receptor is known.