Cross-presentation of glycoprotein 96-associated antigens on major histocompatibility complex class I molecules requires receptor-mediated endocytosis.
Heat shock proteins (HSPs) like glycoprotein (gp)96 (glucose-regulated protein 94 [grp94]) are able to induce specific cytotoxic T lymphocyte (CTL) responses against cells from which they originate. Here, we demonstrate that for CTL activation by gp96-chaperoned peptides, specific receptor-mediated uptake of gp96 by antigen-presenting cells (APCs) is required. Moreover, we show that in both humans and mice, only professional APCs like dendritic cells (DCs), macrophages, and B cells, but not T cells, are able to bind gp96. The binding is saturable and can be inhibited using unlabeled gp96 molecules. Receptor binding by APCs leads to a rapid internalization of gp96, which colocalizes with endocytosed major histocompatibility complex (MHC) class I and class II molecules in endosomal compartments. Incubation of gp96 molecules isolated from cells expressing an adenovirus type 5 E1B epitope with the DC line D1 results in the activation of E1B-specific CTLs. This CTL activation can be specifically inhibited by the addition of irrelevant gp96 molecules not associated with E1B peptides. Our results demonstrate that only receptor-mediated endocytosis of gp96 molecules leads to MHC class I-restricted re-presentation of gp96-associated peptides and CTL activation; non-receptor-mediated, nonspecific endocytosis is not able to do so. Thus, we provide evidence on the mechanisms by which gp96 is participating in the cross-presentation of antigens from cellular origin.
Singh-Jasuja
H
H
Institute for Cell Biology, Department of Immunology, University of Tübingen, Germany.
Toes
R E
RE
Spee
P
P
Münz
C
C
Hilf
N
N
Schoenberger
S P
SP
Ricciardi-Castagnoli
P
P
Neefjes
J
J
Rammensee
H G
HG
Arnold-Schild
D
D
Schild
H
H
D017501:Adenovirus E1B Proteins / Q000276:immunology; D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D000938:Antigen-Presenting Cells / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology; D004705:Endocytosis / Q000276:immunology*; D006183:H-2 Antigens / Q000276:immunology; D018840:HSP70 Heat-Shock Proteins / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D008264:Macrophages / Q000276:immunology; D008565:Membrane Proteins / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018832:Molecular Chaperones / Q000276:immunology*; D011956:Receptors, Cell Surface / Q000276:immunology*; D014407:Tumor Cells, Cultured
D017501:Adenovirus E1B Proteins; D006183:H-2 Antigens; C032876:H-2Kb protein, mouse; D018840:HSP70 Heat-Shock Proteins; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D008565:Membrane Proteins; D018832:Molecular Chaperones; D011956:Receptors, Cell Surface; C018551:glucose-regulated proteins