标题：Higher Concentrations of Interferon-γ Enhances Uptake and Transport of Dietary Antigens by Human Intestinal Cells: A Study Using Cultured Caco-2 Cells
期刊名称：Journal of Nutritional Science and Vitaminology
印刷版ISSN：0301-4800
电子版ISSN：1881-7742
出版年度：2003
卷号：49
期号：3
页码：179-186
DOI：10.3177/jnsv.49.179
出版社：Center for Academic Publications Japan
摘要：Besides functioning as a mucosal barrier and transporting nutrients, intestinal epithelial cells (IECs) also serve as antigen-presenting cells (APCs). Modification of protein antigens by proteolysis is one of the principal steps in antigen presentation to Th cells. We used a Caco-2 intestinal epithelial cell line to investigate the transepithelial transport of the dietary antigen, ovalbumin (OVA). We also examined the effects of the proinflammatory cytokine interferon-γ (IFN-γ) on the antigen transport process in Caco-2 cell layers. Caco-2 cell layers transferred both intact and degraded OVA from the mucosal to the serosal side. IFN-γ stimulated OVA transport and most of the transported OVA in such cells were degraded. We also examined OVA uptake by Caco-2 cells using immunohistochemical means. Caco-2 cells incorporated OVA in a time-dependent manner and IFN-γ significantly enhanced antigen internalization. Flow cytometry also demonstrated that IFN-γ elevated the internalization of FITC-OVA. We also determined the effects of low and high concentrations of IFN-y on mucosal permeability and internalization of FITC-OVA. Althoughh both 10 and 50ng/mL IFN-γ stimulated mucosal permeability to the same extent, more FITC-OVA was internalized by Caco-2 cells incubated with 50 than with 10ng/mL IFN-y. These results suggest that the effects of IFN-γ on mucosal permeability and the internalization of antigens by intestinal epithelial cells are brought about by different mechanisms. Therefore, higher concentrations of IFN-γ stimulate the uptake, processing, and transport of dietary antigens by IECs.
