The murine gammaherpesvirus-68 gp150 acts as an immunogenic decoy to limit virion neutralization.
Herpesviruses maintain long-term infectivity without marked antigenic variation. They must therefore evade neutralization by other means. Immune sera block murine gammaherpesvirus-68 (MHV-68) infection of fibroblasts, but fail to block and even enhance its infection of IgG Fc receptor-bearing cells, suggesting that the antibody response to infection is actually poor at ablating virion infectivity completely. Here we analyzed this effect further by quantitating the glycoprotein-specific antibody response of MHV-68 carrier mice. Gp150 was much the commonest glycoprotein target and played a predominant role in driving Fc receptor-dependent infection: when gp150-specific antibodies were boosted, Fc receptor-dependent infection increased; and when gp150-specific antibodies were removed, Fc receptor-dependent infection was largely lost. Neither gp150-specific monoclonal antibodies nor gp150-specific polyclonal sera gave significant virion neutralization. Gp150 therefore acts as an immunogenic decoy, distorting the MHV-68-specific antibody response to promote Fc receptor-dependent infection and so compromise virion neutralization. This immune evasion mechanism may be common to many non-essential herpesvirus glycoproteins.
Division of Virology, Department of Pathology, University of Cambridge, Cambridge, United Kingdom.
Laurent
L
Gillet
Janet S
JS
May
Susanna
S
Colaco
Philip G
PG
Stevenson
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D057134:Antibodies, Neutralizing / Q000276:immunology*; D018604:Epitope Mapping; D006023:Glycoproteins / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D011961:Receptors, Fc / Q000276:immunology; D018144:Rhadinovirus / Q000276:immunology*; D014764:Viral Proteins / Q000276:immunology*; D014771:Virion / Q000276:immunology*
D000911:Antibodies, Monoclonal; D057134:Antibodies, Neutralizing; D006023:Glycoproteins; D007074:Immunoglobulin G; D011961:Receptors, Fc; D014764:Viral Proteins