Why glycosylation matters in building a better flu vaccine.

Why glycosylation matters in building a better flu vaccine.
Mol Cell Proteomics. 2019 Oct 11;:
Authors: Chang D, Zaia J
Abstract
Low vaccine efficacy against seasonal influenza A virus (IAV) stems from the ability of the virus to evade existing immunity while maintaining fitness. While most potent neutralizing antibodies bind antigenic sites on the globular head domain of the IAV envelope glycoprotein hemagglutinin (HA), the error-prone IAV polymerase enables rapid evolution of key antigenic sites, resulting in immune escape.  Significantly, the appearance of new N-glycosylation consensus sequences (sequons, NXT/NXS, rarely NXC) on the HA globular domain occurs among the more prevalent mutations as an IAV strain undergoes antigenic drift. The appearance of new glycosylation shields underlying amino acid residues from antibody contact, tunes receptor specificity, and balances receptor avidity with virion escape, all of which help maintain viral propagation through seasonal mutations. The World Health Organization selects seasonal vaccine strains based on information from surveillance, laboratory, and clinical observations. While the genetic sequences are known, mature glycosylated structures of circulating strains are not defined.  In this review, we summarize mass spectrometric methods for quantifying site-specific glycosylation in IAV strains, and compare the evolution of IAV glycosylation to that of human immunodeficiency virus.Â...

Source: Molecular and Cellular Proteomics : MCP - October 10, 2019 Category: Molecular Biology Authors: Chang D, Zaia J Tags: Mol Cell Proteomics Source Type: research