title: Interferon-gamma mediates antigen trafficking to MHC class II-positive late endosomes of enterocytes.
abstract: MHC class II-positive late endosomes of enterocytes are thought to be involved in antigen presentation to CD4(+) T cells. In contrast to enterocytes of BALB/c mice, severe combined immunodeficiency (SCID) enterocytes lack MHC class II expression and fail to transport internalized ovalbumin (OVA) into late endosomes. IFN-gamma is known to induce MHC class II in enterocytes and antigen targeting to late endosomes in macrophages. In this study, we investigated the influence of IFN-gamma and MHC class II on the processes of antigen traffic in enterocytes. Subcellular targeting of OVA and MHC class II expression within enterocytes were examined in SCID, IFN-gamma-treated SCID, BALB/c and C57BL/6 MHC class II knockout (KO) mice after a single feed with OVA. Sorting of OVA into late endosomes was found in enterocytes from BALB/c, C57BL/6 KO and IFN-gamma-stimulated SCID mice, but not from untreated SCID mice. MHC class II expression was restricted to enterocytes of IFN-gamma-treated SCID and BALB/c mice, present at basolateral membranes and within endosomal compartments. These enterocytes further revealed colocalization of class II antigens and OVA in endosomes. We suggest that antigen trafficking into late endosomes of enterocytes is mediated by IFN-gamma and occurs in the absence of MHC class II.
authors.affiliation: Institut für Anatomie, Universität zu Lübeck, Lübeck, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Büning
authors.forename: Martina
authors.initials: M
authors.lastname: Schmitz
authors.forename: Birthe
authors.initials: B
authors.lastname: Repenning
authors.forename: Diether
authors.initials: D
authors.lastname: Ludwig
authors.forename: Marcus Alexander
authors.initials: MA
authors.lastname: Schmidt
authors.forename: Stephan
authors.initials: S
authors.lastname: Strobel
authors.forename: Klaus-Peter
authors.initials: KP
authors.lastname: Zimmer
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000187:drug effects* / Q000276:immunology; D015703:Antigens, CD / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D004705:Endocytosis / Q000502:physiology; D011992:Endosomes / Q000276:immunology / Q000378:metabolism*; D020895:Enterocytes / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D007150:Immunohistochemistry; D007371:Interferon-gamma / Q000276:immunology / Q000494:pharmacology*; D007583:Jejunum / Q000276:immunology / Q000378:metabolism; D051907:Lysosomal Membrane Proteins; D051379:Mice; D018345:Mice, Knockout; D016513:Mice, SCID; D046529:Microscopy, Electron, Transmission; D010047:Ovalbumin / Q000276:immunology
chemical_list: D015703:Antigens, CD; D000949:Histocompatibility Antigens Class II; D051907:Lysosomal Membrane Proteins; D007371:Interferon-gamma; D010047:Ovalbumin