title: Fusion of the Human Cytomegalovirus pp65 antigen with both ubiquitin and ornithine decarboxylase additively enhances antigen presentation to CD8(+) T cells in human dendritic cells.
abstract: Antigenic molecules are modified for targeting to the proteasome by ubiquitin (Ub) or by a Ub-independent system such as ornithine decarboxylase (ODC) to be presented by MHC class I molecules. In this study, we compared the immunogenicity of human cytomegalovirus pp65 antigen fused with Ub and/or ODC, using RNA electroporation of human dendritic cells. Among the C-terminal mutants of Ub (G76, A76, and V76), Ub(G) showed the best ability to enhance the degradation of a target protein and stimulate T cells. The pp65 antigens fused with either Ub(G) or ODC enhanced the stimulation to CD8(+) T cells, and the effects of Ub(G) and ODC were similar. Furthermore, the fusion of both Ub and ODC additively increased immunogenicity compared with the single-fusion proteins. The fusion of Ub(G) and ODC enhanced primarily the stimulation of CD8(+) rather than CD4(+) T cells and more efficiently induced pp65-specific T cells in vitro. These additive effects of Ub and ODC in antigen processing may provide improved strategies to stimulate CD8(+) T cells for the development of immunotherapies against the variety of viral diseases and cancers.
authors.affiliation: Department of Microbiology, College of Medicine, Catholic University of Korea, Seoul 137-701, Republic of Korea.
authors.forename: Min-Ji
authors.initials: MJ
authors.lastname: Park
authors.forename: Eun-Kyung
authors.initials: EK
authors.lastname: Kim
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Han
authors.forename: Hyun-Woo
authors.initials: HW
authors.lastname: Cho
authors.forename: Hyun-Jung
authors.initials: HJ
authors.lastname: Sohn
authors.forename: Su-Yeon
authors.initials: SY
authors.lastname: Kim
authors.forename: Tai-Gyu
authors.initials: TG
authors.lastname: Kim
mesh_terms: D017951:Antigen Presentation; D000956:Antigens, Viral / Q000276:immunology / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D003587:Cytomegalovirus / Q000276:immunology / Q000378:metabolism; D003713:Dendritic Cells / Q000378:metabolism*; D018274:Electroporation; D015395:Histocompatibility Antigens Class I / Q000276:immunology / Q000378:metabolism; D006801:Humans; D009955:Ornithine Decarboxylase / Q000276:immunology / Q000378:metabolism*; D010750:Phosphoproteins / Q000276:immunology / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000276:immunology / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D025801:Ubiquitin / Q000276:immunology / Q000378:metabolism*; D014763:Viral Matrix Proteins / Q000276:immunology / Q000378:metabolism*
chemical_list: D000956:Antigens, Viral; D015395:Histocompatibility Antigens Class I; D010750:Phosphoproteins; D011993:Recombinant Fusion Proteins; D025801:Ubiquitin; D014763:Viral Matrix Proteins; C065418:cytomegalovirus matrix protein 65kDa; D046988:Proteasome Endopeptidase Complex; D009955:Ornithine Decarboxylase