title: Pseudotyped single-cycle simian immunodeficiency viruses expressing gamma interferon augment T-cell priming responses in vitro.
abstract: To increase the safety and efficacy of human immunodeficiency virus vaccines, several groups have conducted studies using the macaque model with single-cycle replicating simian immunodeficiency viruses (SIVs). However, these constructs had poor or diminished efficacy compared to live attenuated vaccines. We previously showed that immunization of macaques with live attenuated SIV with a deletion in the nef gene and expressing gamma interferon (IFN-gamma) results in significantly enhanced safety and efficacy. To further enhance safety, we constructed and characterized single-cycle SIVs, pseudotyped with the glycoprotein of vesicular stomatitis virus, expressing different levels of macaque IFN-gamma. Expression of IFN-gamma did not alter the infectivity or antigenicity of pseudotyped SIV. The transduction of dendritic cells (DCs) by IFN-gamma-expressing particles resulted in the up-regulation of costimulatory and major histocompatibility complex molecules. Furthermore, T cells primed with DCs transduced by SIV particles expressing high levels of IFN-gamma and then stimulated with SIV induced significantly higher numbers of spot-forming cells in an enzyme-linked immunospot assay than did T cells primed with DCs transduced with SIV particles lacking the cytokine. In conclusion, we demonstrated that the transduction of DCs in vitro with pseudotyped single-cycle SIVs expressing IFN-gamma increased DC activation and augmented T-cell priming activity.
authors.affiliation: International Laboratory of Molecular Biology for Tropical Disease Agents, University of California, Davis, CA 95616, USA.
authors.forename: Yue
authors.initials: Y
authors.lastname: Peng
authors.forename: Fan-ching
authors.initials: FC
authors.lastname: Lin
authors.forename: Paulo H
authors.initials: PH
authors.lastname: Verardi
authors.forename: Leslie A
authors.initials: LA
authors.lastname: Jones
authors.forename: Michael B
authors.initials: MB
authors.lastname: McChesney
authors.forename: Tilahun D
authors.initials: TD
authors.lastname: Yilma
mesh_terms: D016915:AIDS Vaccines / Q000235:genetics / Q000276:immunology; D000818:Animals; D017951:Antigen Presentation; D001483:Base Sequence; D002460:Cell Line; D004274:DNA, Recombinant / Q000235:genetics; D003713:Dendritic Cells / Q000276:immunology / Q000821:virology; D015683:Gene Products, gag / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D006801:Humans; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000096:biosynthesis* / Q000235:genetics; D008253:Macaca mulatta; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology; D051381:Rats; D011994:Recombinant Proteins; D015302:Simian Immunodeficiency Virus / Q000235:genetics / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology
chemical_list: D016915:AIDS Vaccines; D004274:DNA, Recombinant; C028391:G protein, vesicular stomatitis virus; C066594:Gag protein p27, Simian immunodeficiency virus; D015683:Gene Products, gag; D008562:Membrane Glycoproteins; D011994:Recombinant Proteins; D014759:Viral Envelope Proteins; D007371:Interferon-gamma