The Three-dimensional Structure of Surface Antigens from Animal Viruses

Abstract

Significant advances have been made recently in our understanding of the structural basis of immune recognition of viral antigens and intact animal viruses. X-ray crystallographic analyses have provided the three-dimensional structures to two viral antigens: i.e., the hemagglutinin (HA) [1–4] and neuraminidase (NA) [5–7] of influenza virus and of two animal viruses, the poliomyelitis virus [8] and rhino virus 14 [9] of the picornavirus family. The structure of the poliomyelitis virus is detailed by Hogle, Chow, and Filman in Chapter 1 of this book. The main goal in determining these structures was to correlate their three-dimensional structure and biological function with their ability to evade neutralization by the immune system. The main achievements to date have been primarily concerned with understanding viral recognition by the humoral system. This has been facilitated by the ability to target anti-protein or anti-peptide mouse monoclonal antibodies against specific antigens and viruses. In addition, the ability to follow the evolution of a virus from a defined pandemic strain has enabled evaluation of natural antigenic variation and selection in the human population. By comparison, the analysis of recognition of viral antigens by the cellular system has been more technologically difficult; however, rapid advances in this direction are being made at present, with the ability both to clone T cells and to understand antigen presentation and processing.