Comparative Epitope Stability Analysis of Influenza A Virus Antigenic Proteins

Abstract

Influenza A Viruses are the most virulent human pathogens among the three influenza types (Influenza A, B, C) and cause the most severe disease. The influenza A virus are subdivided into different serotypes based on the antibody response to these viruses and they resulted in many number of human pandemic deaths. The known flu pandemics are from 1918 Spanish flu, which is the serious pandemic in recent history and the most recent one was the 2009 flu pandemic. In each of the pandemics, different subtypes of H & N of Influenza A virus strain are involved. The process of antigenic shift in between species as well subtype combinations are leading to the novel strains which are highly virulent.  As the subtypes are based on two important proteins viz. Hemagglutinin and Neuraminidase (H&N), our focus is to identify the amino acid changes/mutations in the epitopes of H1-H16 and N1-N9 strains which are evolved through time. The epitopic regions are predicted using Immune Epitope DataBase, and the predicted epitopic peptide is modeled using the CPH modeling server and each of the modeled epitope(s) are subjected to structural stability analysis using Hyperchem program. Epitope modeling and energy value comparison studies of Influenza A Virus epitopes showed that recent (2010) strains - H5 and N6 are possessing higher energies indicating  their instability and thereby are more prone to mutations and may become highly pathogenic (virulent) in the near future than the earlier H1 and N1 strains.