IgG fc receptors provide an alternative infection route for murine gamma-herpesvirus-68.
BACKGROUND
Herpesviruses can be neutralized in vitro but remain infectious in immune hosts. One difference between these settings is the availability of immunoglobulin Fc receptors. The question therefore arises whether a herpesvirus exposed to apparently neutralizing antibody can still infect Fc receptor(+) cells.


RESULTS
Immune sera blocked murine gamma-herpesvirus-68 (MHV-68) infection of fibroblasts, but failed to block and even enhanced its infection of macrophages and dendritic cells. Viral glycoprotein-specific monoclonal antibodies also enhanced infection. MHV-68 appeared to be predominantly latent in macrophages regardless of whether Fc receptors were engaged, but the infection was not abortive and new virus production soon overwhelmed infected cultures. Lytically infected macrophages down-regulated MHC class I-restricted antigen presentation, endocytosis and their response to LPS.


CONCLUSIONS
IgG Fc receptors limit the neutralization of gamma-herpesviruses such as MHV-68.
Rosa
Gustavo T
GT
Division of Virology, Department of Pathology, University of Cambridge, Cambridge, United Kingdom.
Gillet
Laurent
L
Smith
Christopher M
CM
de Lima
Brigitte D
BD
Stevenson
Philip G
PG
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D057134:Antibodies, Neutralizing / Q000276:immunology; D017951:Antigen Presentation; D002478:Cells, Cultured; D003587:Cytomegalovirus / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics; D005347:Fibroblasts / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006023:Glycoproteins / Q000276:immunology; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006566:Herpesviridae Infections / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D017874:Immediate-Early Proteins / Q000235:genetics; D017737:Macrophages, Peritoneal / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009500:Neutralization Tests; D011401:Promoter Regions, Genetic / Q000235:genetics; D011961:Receptors, Fc / Q000276:immunology*; D017452:Receptors, IgG / Q000276:immunology*; D018144:Rhadinovirus / Q000276:immunology*; D014412:Tumor Virus Infections / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D014771:Virion / Q000276:immunology*; D014779:Virus Replication
D000911:Antibodies, Monoclonal; D057134:Antibodies, Neutralizing; D004279:DNA, Viral; D006023:Glycoproteins; D017874:Immediate-Early Proteins; D011961:Receptors, Fc; D017452:Receptors, IgG; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins