title: Misdirection of endosomal trafficking mediated by herpes simplex virus-encoded glycoprotein B.
abstract: Herpes simplex virus (HSV)-encoded glycoprotein B (gB) is the most abundant protein in the viral envelope and promotes fusion of the virus with the cellular membrane. In the present study, we found that gB impacts on the major histocompatibility complex (MHC)-II pathway of antigen presentation by fostering homotypic fusion of early endosomes and trapping MHC-II molecules in these altered endosomes. By using an overexpression approach, we demonstrated that transient expression of gB induces giant vesicles of early endosomal origin, which contained Rab5, early endosomal antigen 1 (EEA1), and large amounts of MHC-II molecules [human leukocyte antigen (HLA)-DR, and HLA-DM], but no CD63. In HSV-1-infected and stably transfected cell lines that expressed lower amounts of gB, giant endosomes were not observed, but strongly increased amounts of HLA-DR and HLA-DM were found in EEA1+early endosomes. We used these giant vesicles as a model system and revealed that gB interacts with Rab5 and EEA1, and that gB-induced homotypic fusion of early endosomes to giant endosomes requires phosphatidylinositol 3-phosphate, the activity of solubleN-ethylmaleimide-sensitive factor attachment protein receptors, and the cytosolic gB sequence889YTQVPN894We conclude that gB expression alters trafficking of molecules of the HLA-II processing pathway, which leads to increased retention of MHC-II molecules in early endosomal compartments, thereby intercepting antigen presentation.-Niazy, N., Temme, S., Bocuk, D., Giesen, C., König, A., Temme, N., Ziegfeld, A., Gregers, T. F., Bakke, O., Lang, T., Eis-Hübinger, A. M., Koch, N. Misdirection of endosomal trafficking mediated by herpes simplex virus-encoded glycoprotein B.
authors.affiliation: Section of Immunobiology, Institute of Genetics, University of Bonn, Bonn, Germany.
authors.forename: Naima
authors.initials: N
authors.lastname: Niazy
authors.affiliation: Section of Immunobiology, Institute of Genetics, University of Bonn, Bonn, Germany; sebastian.Temme@uni-duesseldorf.de.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Temme
authors.affiliation: Section of Immunobiology, Institute of Genetics, University of Bonn, Bonn, Germany.
authors.forename: Derya
authors.initials: D
authors.lastname: Bocuk
authors.affiliation: Section of Immunobiology, Institute of Genetics, University of Bonn, Bonn, Germany.
authors.forename: Carmen
authors.initials: C
authors.lastname: Giesen
authors.affiliation: Section of Immunobiology, Institute of Genetics, University of Bonn, Bonn, Germany.
authors.forename: Angelika
authors.initials: A
authors.lastname: König
authors.affiliation: Section of Immunobiology, Institute of Genetics, University of Bonn, Bonn, Germany.
authors.forename: Nadine
authors.initials: N
authors.lastname: Temme
authors.affiliation: Section of Immunobiology, Institute of Genetics, University of Bonn, Bonn, Germany.
authors.forename: Angelique
authors.initials: A
authors.lastname: Ziegfeld
authors.affiliation: Department of Biosciences, University of Oslo, Oslo, Norway.
authors.forename: Tone F
authors.initials: TF
authors.lastname: Gregers
authors.affiliation: Department of Biosciences, University of Oslo, Oslo, Norway.
authors.forename: Oddmund
authors.initials: O
authors.lastname: Bakke
authors.affiliation: Membrane Biochemistry, Life and Medical Sciences Institute, University of Bonn, Bonn, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Lang
authors.affiliation: Institute of Virology, University of Bonn Medical Centre, Bonn, Germany.
authors.forename: Anna M
authors.initials: AM
authors.lastname: Eis-Hübinger
authors.affiliation: Section of Immunobiology, Institute of Genetics, University of Bonn, Bonn, Germany.
authors.forename: Norbert
authors.initials: N
authors.lastname: Koch
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D011992:Endosomes / Q000378:metabolism* / Q000821:virology; D006681:HLA-D Antigens / Q000378:metabolism; D006684:HLA-DR Antigens / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism; D021381:Protein Transport; D060149:Tetraspanin 30 / Q000378:metabolism; D033921:Vesicular Transport Proteins / Q000378:metabolism; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020696:rab5 GTP-Binding Proteins / Q000378:metabolism
chemical_list: D006681:HLA-D Antigens; C084245:HLA-DM antigens; D006684:HLA-DR Antigens; D018129:Phosphatidylinositol Phosphates; D060149:Tetraspanin 30; D033921:Vesicular Transport Proteins; D014759:Viral Envelope Proteins; C093846:early endosome antigen 1; C040495:glycoprotein B, Simplexvirus; C055525:phosphatidylinositol 3-phosphate; C427755:RAB5C protein, human; D020696:rab5 GTP-Binding Proteins
keywords: HLA class II; HSV-1; antigen processing compartments; giant endosomal vesicles; signal sequences