title: Targeting to static endosome is required for efficient cross-presentation of endoplasmic reticulum-resident oxygen-regulated protein 150-peptide complexes.
abstract: Heat shock proteins (HSPs) such as Hsp70, gp96, and Hsp90 have been shown to elicit intriguing, efficient CTL responses by cross-presentation via an as yet entirely unknown mechanism. Oxygen-regulated protein 150 (ORP150), also known as grp170, is an endoplasmic reticulum-resident HSP and is up-regulated by hypoxia. It has been demonstrated that ORP150 binds tumor-associated Ag peptides within cancer cells. Immunization with an ORP150-tumor Ag complex has been shown to generate tumor-specific CTLs. Most recently, it has been shown that exogenous ORP150 induces cross-presentation of a chaperoned Ag, thereby stimulating Ag-specific CTLs. However, the mechanism underlying this efficient cross-presentation is still unsolved. In this study, we show that the ORP150-precursor peptide complex can elicit CTL response through cross-presentation as well as the CD4(+) T cell response by dendritic cells. Furthermore, we observed that the internalized ORP150-peptide complex, but not OVA protein, which was not cross-presented, was sorted to the Rab5(+), EEA1(+) static early endosome, followed by translocation to a recycling endosome, where the ORP150-chaperoned peptide was processed and bound to MHC class I molecules. Moreover, we observed that immunization of mice with ORP150-peptide complexes elicited strong peptide-specific CTLs and antitumor effects in vivo. Our data indicate that targeting of the Ag to a "static" early endosme by ORP150 is required for the efficient cross-presentation.
authors.affiliation: Department of Pathology, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Goro
authors.initials: G
authors.lastname: Kutomi
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Tamura
authors.forename: Koichi
authors.initials: K
authors.lastname: Okuya
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Hirohashi
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Kamiguchi
authors.forename: Jun
authors.initials: J
authors.lastname: Oura
authors.forename: Keita
authors.initials: K
authors.lastname: Saito
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Torigoe
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ogawa
authors.forename: Koichi
authors.initials: K
authors.lastname: Hirata
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Sato
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D002454:Cell Differentiation / Q000276:immunology; D045142:Cross-Priming / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000276:immunology / Q000378:metabolism*; D011992:Endosomes / Q000276:immunology / Q000378:metabolism*; D005260:Female; D018840:HSP70 Heat-Shock Proteins; D050884:HSP72 Heat-Shock Proteins / Q000276:immunology / Q000378:metabolism; D006801:Humans; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018832:Molecular Chaperones / Q000276:immunology / Q000378:metabolism; D008969:Molecular Sequence Data; D046912:Multiprotein Complexes / Q000276:immunology* / Q000378:metabolism; D010101:Oxygen Consumption / Q000276:immunology*; D010446:Peptide Fragments / Q000276:immunology / Q000378:metabolism*; D011498:Protein Precursors / Q000276:immunology / Q000378:metabolism; D011499:Protein Processing, Post-Translational / Q000276:immunology; D021381:Protein Transport / Q000276:immunology; D011506:Proteins / Q000276:immunology / Q000378:metabolism*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000378:metabolism
chemical_list: D018840:HSP70 Heat-Shock Proteins; D050884:HSP72 Heat-Shock Proteins; D018832:Molecular Chaperones; D046912:Multiprotein Complexes; D010446:Peptide Fragments; D011498:Protein Precursors; D011506:Proteins; C050087:oxygen-regulated proteins