کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6097083 1209900 2007 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
T84-Intestinal Epithelial Exosomes Bear MHC Class II/Peptide Complexes Potentiating Antigen Presentation by Dendritic Cells
موضوعات مرتبط
علوم پزشکی و سلامت پزشکی و دندانپزشکی بیماری‌های گوارشی
پیش نمایش صفحه اول مقاله
T84-Intestinal Epithelial Exosomes Bear MHC Class II/Peptide Complexes Potentiating Antigen Presentation by Dendritic Cells
چکیده انگلیسی
Background & Aims: Intestinal epithelial cells release antigen-presenting vesicles (exosomes) bearing major histocompatibility complex class II/peptide complexes stimulating specific immune responses in vivo. To characterize further the role of human epithelial exosomes in antigen presentation, their capacity to load antigenic peptides, bind immune target cells, and induce T-cell activation was analyzed in vitro. Methods: The capacity of exosomes derived from the HLA-DR4-expressing, intestinal epithelial cell line T84 to load the HLA-DR4-specific peptide 3H-HSA 64-76 and to activate a HLA-DR4-restricted T-cell hybridoma was tested in the presence or absence of human monocyte-derived dendritic cells (DCs). Interaction of fluorescein isothiocyanate-labeled exosomes with T cells and DCs was analyzed by flow cytometry and confocal microscopy. Results: T84-derived exosomes, enriched in CD9, CD81, CD82, and A33 antigen, were capable of binding specifically human serum albumin (HSA) 64-76 peptide on HLA-DR4 molecules and of interacting preferentially with DCs. HSA-loaded exosomes were unable to activate the T-cell hybridoma directly but induced a productive T-cell activation through DCs. When HSA peptide was bound to exosomal HLA-DR4 molecules instead of in a soluble form, the threshold of peptide presentation by DCs was markedly decreased (×10−3). Conclusions: Exosomes released by intestinal epithelial cells bear exogenous peptides complexed to major histocompatibility complex class II molecules and interact preferentially with DCs, strongly potentiating peptide presentation to T cells. Epithelial exosomes constitute a powerful link between luminal antigens and local immune cells by mediating the transfer of tiny amounts of luminal antigenic information and facilitating immune surveillance at mucosal surfaces.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Gastroenterology - Volume 132, Issue 5, May 2007, Pages 1866-1876
نویسندگان
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