Antibody-induced internalization of viral glycoproteins and gE-gI Fc receptor activity protect pseudorabies virus-infected monocytes from efficient complement-mediated lysis.
Pseudorabies virus (PRV)-infected blood monocytes are able to transport virus throughout the body of vaccination-immune pigs. PRV-infected monocytes express viral glycoproteins in their plasma membrane that can be recognized by virus-specific antibodies. Recently, it has been shown that addition of PRV-specific polyclonal immunoglobulins to PRV-infected monocytes at 37 degrees C induces internalization of the majority of plasma membrane-expressed viral glycoproteins. This study investigated whether this process may interfere with efficient antibody-dependent complement-mediated lysis (ADCML) of infected monocytes. Therefore, an ADCML assay was set up in vitro. A significant decrease in the percentage of cells lysed by ADCML was observed when antibody-induced internalization of PRV glycoproteins occurred (P<0.005). Furthermore, it is shown (i) that the PRV gE-gI complex, which, like certain other alpha herpesvirus orthologues, possesses IgG-binding capacity, aids in avoiding efficient ADCML of PRV-infected monocytes and (ii) that the efficiency of PRV gE-gI-mediated evasion of ADCML can be decreased by the presence of gE-gI-specific antibodies.
Van de Walle
Gerlinde R
GR
Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.
Favoreel
Herman W
HW
Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.
Nauwynck
Hans J
HJ
Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.
Pensaert
Maurice B
MB
Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.
D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D000920:Antibody-Dependent Cell Cytotoxicity / Q000276:immunology; D002478:Cells, Cultured; D003170:Complement Pathway, Alternative; D003601:Cytotoxicity Tests, Immunologic; D006023:Glycoproteins / Q000276:immunology*; D011558:Herpesvirus 1, Suid / Q000276:immunology* / Q000472:pathogenicity; D009000:Monocytes / Q000821:virology; D011557:Pseudorabies / Q000276:immunology* / Q000821:virology; D011961:Receptors, Fc / Q000276:immunology*; D013552:Swine; D014759:Viral Envelope Proteins / Q000276:immunology*; D014774:Virulence / Q000276:immunology
D000914:Antibodies, Viral; D006023:Glycoproteins; D011961:Receptors, Fc; D014759:Viral Envelope Proteins; C089580:glycoprotein E, Suid herpesvirus 1; C042966:pseudorabies virus glycoproteins