title: Urea-mediated cross-presentation of soluble Epstein-Barr virus BZLF1 protein.
abstract: Soluble extracellular proteins usually do not enter the endogenous human leukocyte antigen (HLA) I-dependent presentation pathway of antigen-presenting cells, strictly impeding their applicability for the re-stimulation of protein-specific CD8(+) cytotoxic T lymphocytes (CTL). Here we present for the Epstein-Barr virus (EBV) BZLF1 a novel strategy that facilitates protein translocation into antigen-presenting cells by its solubilisation in high molar urea and subsequent pulsing of cells in presence of low molar urea. Stimulation of PBMC from HLA-matched EBV-seropositive individuals with urea-treated BZLF1 but not untreated BZLF1 induces an efficient reactivation of BZLF1-specific CTL. Urea-treated BZLF1 (uBZLF1) enters antigen-presenting cells in a temperature-dependent manner by clathrin-mediated endocytosis and is processed by the proteasome into peptides that are bound to nascent HLA I molecules. Dendritic cells and monocytes but also B cells can cross-present uBZLF1 in vitro. The strategy described here has potential for use in the development of improved technologies for the monitoring of protein-specific CTL.
authors.affiliation: Institute of Medical Microbiology, University of Regensburg, Germany.
authors.forename: Sascha
authors.initials: S
authors.lastname: Barabas
authors.forename: Regina
authors.initials: R
authors.lastname: Gary
authors.forename: Tanja
authors.initials: T
authors.lastname: Bauer
authors.forename: Juha
authors.initials: J
authors.lastname: Lindner
authors.forename: Petra
authors.initials: P
authors.lastname: Lindner
authors.forename: Birgit
authors.initials: B
authors.lastname: Weinberger
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Jilg
authors.forename: Hans
authors.initials: H
authors.lastname: Wolf
authors.forename: Ludwig
authors.initials: L
authors.lastname: Deml
mesh_terms: D000938:Antigen-Presenting Cells / Q000276:immunology / Q000821:virology; D001402:B-Lymphocytes; D002478:Cells, Cultured; D045142:Cross-Priming / Q000276:immunology*; D003713:Dendritic Cells; D004705:Endocytosis; D004854:Herpesvirus 4, Human / Q000737:chemistry*; D015395:Histocompatibility Antigens Class I; D006801:Humans; D008722:Methods; D009000:Monocytes; D012995:Solubility; D015534:Trans-Activators / Q000276:immunology*; D014508:Urea
chemical_list: C063676:BZLF1 protein, Herpesvirus 4, Human; D015395:Histocompatibility Antigens Class I; D015534:Trans-Activators; D014508:Urea