Hepatitis B virus surface antigen suppresses the activation of monocytes through interaction with a serum protein and a monocyte-specific receptor.
During hepatitis B virus (HBV) infection, high numbers of non-infectious HBV surface antigen (HBsAg) particles are present in circulation. It is shown here that recombinant HBsAg (rHBsAg) particles, which contain the S protein only, bind almost exclusively to monocytes. Attachment of rHBsAg to the THP-1 pre-monocytic cell line occurs upon 1,25-dihydroxyvitamin D3-induced differentiation. Binding to monocytes is enhanced by a heat-labile serum protein and is inhibited by Ca(2+)/Mg(2+), low pH and an HBsAg-specific monoclonal antibody. Furthermore, it is shown that rHBsAg suppresses lipopolysaccharide- and IL-2-induced production of cytokines. These results suggest the existence of a monocyte-specific receptor, the engagement of which by HBsAg suppresses the activity of these cells.
Vanlandschoot
Peter
P
Center for Vaccinology, Department of Clinical Biology, Microbiology and Immunology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium1.
Van Houtte
Freya
F
Center for Vaccinology, Department of Clinical Biology, Microbiology and Immunology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium1.
Roobrouck
Annelies
A
Center for Vaccinology, Department of Clinical Biology, Microbiology and Immunology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium1.
Farhoudi
Ali
A
Center for Vaccinology, Department of Clinical Biology, Microbiology and Immunology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium1.
Leroux-Roels
Geert
G
Center for Vaccinology, Department of Clinical Biology, Microbiology and Immunology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium1.
D000911:Antibodies, Monoclonal / Q000494:pharmacology; D001798:Blood Proteins / Q000494:pharmacology; D002117:Calcitriol; D002118:Calcium / Q000494:pharmacology; D002454:Cell Differentiation; D002478:Cells, Cultured; D016207:Cytokines / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D006514:Hepatitis B Surface Antigens / Q000276:immunology*; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007376:Interleukin-2; D018950:Lipopolysaccharide Receptors / Q000378:metabolism; D008070:Lipopolysaccharides; D008274:Magnesium / Q000494:pharmacology; D009000:Monocytes / Q000276:immunology* / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D011994:Recombinant Proteins / Q000276:immunology
D000911:Antibodies, Monoclonal; D001798:Blood Proteins; D016207:Cytokines; D006514:Hepatitis B Surface Antigens; D007376:Interleukin-2; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D011994:Recombinant Proteins; D002117:Calcitriol; D008274:Magnesium; D002118:Calcium