Proteomics‐based characterization of hemagglutinins in different strains of influenza virus

Abstract

Infection with influenza A (subtypes H1N1 and H3N2) or B viruses results in over half a million deaths worldwide every year. Frequent antigenic changes (drift) in two major viral surface proteins hemagglutinin (HA) and neuraminidase lead to the constant emergence of antigenically distinct virus strains against which there is sub-optimal immunity in the population. Consequently the suitability of the viral strains included in the trivalent influenza vaccine (TIV) has to be re-evaluated annually. While virus seeds selected for vaccine manufacture are very well characterized, there is no assay in place to identify the source of HA in the formulated trivalent vaccine. Our study describes a proteomics-based method to identify the HA strain (not just subtype) and more fully characterize the final vaccine product. Unique and shared tryptic peptides of HAs were predicted by in silico tryptic digest of different influenza A and B virus strains. Recombinant HA and whole virus preparations of selected strains were then digested to identify the peptides detected by MS. Both subtype and strain-specific peptides were observed. The feasibility of this method to accurately identify HA strains in an inactivated TIV was tested using a 2006/2007 formulation. Each of the three HAs in the vaccine was identified in addition to a number of other viral and non-viral proteins. In summary, MS is a powerful method that is both specific and inclusive; in a single analysis, HAs of individual virus strains can be identified and the composition of the TIV fully characterized.

A monoclonal antibody‐based immunoassay for measuring the potency of 2009 pandemic influenza H1N1 vaccines

“…The SRID is not particularly sensitive, it is relatively low throughput, and the assay format requires large amounts of strain‐specific reagents. Several alternative methods for HA quantification have recently been described, including techniques based on HPLC, mass spectrometry, surface plasmon resonance, and ELISA Several of the techniques that are under evaluation have selective advantages over the SRID and show promise for further development as potential alternative or replacement potency assays. For example, ELISA methods are high throughput, amenable to automation, and miniaturized in comparison with the SRID assay, thus reducing the demand for reagents.…”

A Novel Synthetic Receptor-Based Immunoassay for Influenza Vaccine Quantification

“…Interestingly, combining the two methods SE and RP-HPLC in two-dimensional (2D) HPLC resulted in higher sensitivity and selectivity for HA1 quantification [30]. Tandem mass spectrometry (MS)-based approaches were also investigated for characterization of influenza vaccines [31], [32], [33], [34]. Although these techniques have several advantages, especially in selectivity and sensitivity, they require expensive equipment and highly trained technical staff.…”

Mass spectrometric approaches to study enveloped viruses: New possibilities for structural biology and prophylactic medicine

“…Vaccination is currently the most effective preventive measure for limiting the expansion of influenza epidemics. MS allows researchers to qualita tively characterize a vaccine preparation: to determine possible mutations in the antigens and to reveal admix tures of proteins of chick embryo or cell cultures used for growing the virus [24].…”