title: Generation of immune responses against hepatitis C virus by dendritic cells containing NS5 protein-coated microparticles.
abstract: Dendritic cells (DCs) internalize and process antigens as well as activate cellular immune responses. The aim of this study was to determine the capacity of DCs that contain antigen-coated magnetic beads to induce immunity against the nonstructural hepatitis C virus (HCV) antigen 5 (NS5). Splenocytes derived from Fms-like tyrosine kinase receptor 3 (Flt3) ligand-pretreated BALB/c mice were incubated with magnetic beads coated with HCV NS5, lipopolysaccharide (LPS), and/or anti-CD40; purified; and used for immunization. Cellular immunity was measured using cytotoxic T-lymphocyte (CTL) and T-cell proliferation assays, intracellular cytokine staining, and a syngeneic tumor challenge using NS5-expressing SP2/0 myeloma cells in vivo. Splenocytes isolated from animals vaccinated with DCs containing beads coated with NS5, LPS, and anti-CD40 secreted elevated levels of interleukin-2 (IL-2) and gamma interferon in the presence of NS5. The numbers of CD4(+), IL-2-producing cells were increased >5-fold in the group immunized with DCs containing beads coated with NS5, LPS, and anti-CD40, paralleled by an enhanced splenocyte proliferative response. Immunization promoted antigen-specific CTL activity threefold compared to the level for control mice and significantly reduced the growth of NS5-expressing tumor cells in vivo. Thus, strategies that employ NS5-coated beads induce cellular immune responses in mice, which correlate well with the natural immune responses that occur in individuals who resolve HCV.
authors.affiliation: The Liver Research Center, Rhode Island Hospital and The Warren Alpert Medical School of Brown University, Providence, Rhode Island 02903, USA.
authors.forename: Stephan
authors.initials: S
authors.lastname: Gehring
authors.forename: Stephen H
authors.initials: SH
authors.lastname: Gregory
authors.forename: Philip
authors.initials: P
authors.lastname: Wintermeyer
authors.forename: Costica
authors.initials: C
authors.lastname: Aloman
authors.forename: Jack R
authors.initials: JR
authors.lastname: Wands
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D016207:Cytokines / Q000096:biosynthesis; D003601:Cytotoxicity Tests, Immunologic; D003602:Cytotoxicity, Immunologic; D003713:Dendritic Cells / Q000276:immunology*; D005260:Female; D016174:Hepacivirus / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008863:Microspheres; D013601:T-Lymphocytes / Q000276:immunology; D017361:Viral Nonstructural Proteins / Q000276:immunology*; D012324:RNA-Dependent RNA Polymerase
chemical_list: D016207:Cytokines; D017361:Viral Nonstructural Proteins; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase