title: A crucial role of macrophages in the immune responses to oral DNA vaccination against hepatitis B virus in a murine model.
abstract: In the previous study, we had shown that live oral vaccination with Salmonella typhimurium delivering plasmid DNA-HBsAg (oral DNA vaccine) evoked a vigorous T cell response and a weak antibody response with predominant subclass IgG2a in mice, suggesting a significant involvement by professional antigen presenting cells (APC). In the present study, this possibility was further studied by infecting peritoneal macrophages (MPhi) with the oral DNA vaccine. Although, the infected cells could only express low level of the viral antigen, they nevertheless stimulated a vigorous lymphocyte proliferation of splenocytes from immune mice, induced these cells to elaborate interferon-gamma and stimulated development of HBV-specific cytotoxicity against target cells expressing the viral antigen. Infusion of the infected MPhi evoked a vigorous Th 1 and cytotoxic T lymphocyte (CTL) response and a weak IgG2a antibody response in mice, which was essentially the same as response to the oral DNA vaccine. In contrast, recombinant protein vaccine evoked a vigorous IgG1 antibody response and a weak T cell response. While, given intramuscularly, the same plasmid DNA vaccine as that contained in the oral DNA vaccine evoked a vigorous IgG1 antibody response and a moderate T cell response in these animals. It was concluded that professional APC may orchestrate the immune response to live oral DNA vaccine and it was of interest to note that different vaccine formulation and routes of administration evoke distinct immune response to HBV.
authors.affiliation: Department of Microbiology, The University of Hong Kong, University Pathology Building, Queen Mary Hospital Compound, Pokfulam Road, Hong Kong, PR China.
authors.forename: B
authors.initials: B
authors.lastname: Zheng
authors.forename: P C
authors.initials: PC
authors.lastname: Woo
authors.forename: M
authors.initials: M
authors.lastname: Ng
authors.forename: H
authors.initials: H
authors.lastname: Tsoi
authors.forename: L
authors.initials: L
authors.lastname: Wong
authors.forename: K
authors.initials: K
authors.lastname: Yuen
mesh_terms: D000284:Administration, Oral; D019264:Adoptive Transfer; D000818:Animals; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D004274:DNA, Recombinant / Q000008:administration & dosage; D005260:Female; D006510:Hepatitis B Antibodies / Q000096:biosynthesis / Q000097:blood / Q000276:immunology; D006514:Hepatitis B Surface Antigens / Q000096:biosynthesis; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000276:immunology*; D007108:Immune Tolerance; D007115:Immunization Schedule; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000097:blood / Q000276:immunology; D007274:Injections, Intraperitoneal; D007275:Injections, Intravenous; D007371:Interferon-gamma / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D008213:Lymphocyte Activation; D017737:Macrophages, Peritoneal / Q000276:immunology* / Q000637:transplantation / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D010957:Plasmids / Q000235:genetics; D012486:Salmonella typhimurium / Q000235:genetics; D013047:Specific Pathogen-Free Organisms; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology / Q000378:metabolism; D014611:Vaccination; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology
chemical_list: D004274:DNA, Recombinant; D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines; D007074:Immunoglobulin G; D019444:Vaccines, DNA; D015847:Interleukin-4; D007371:Interferon-gamma