IgG Fc receptors provide an alternative infection route for murine gamma-herpesvirus-68

Abstract

Background. Herpesviruses can be neutralized in vitro but remain infectious immune hosts. One difference betweeh 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. Principal Findings. 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, Lyticaily infected macrophages down-related MHC class 1-restricted antigen presentation, endocytosis and their response to LPS. Conclusions. IgG Fc receptors limit the neutralization of gamma-herpesviruses such as MHV-68. Copyright © 2007 Rosa et al.