부산대학교 도서관

Dendritic cells (DCs) and macrophages populate the intestinal lamina propria to initiate immune responses required for the maintenance of intestinal homeostasis. To investigate whether CX3CR1+ phagocytes communicate with CD4 T cells during the development of transfer colitis, we established an antigen-driven colitis model induced by the adoptive transfer of DsRed OT-II cells in CX3CR1GFP/+ × RAG−/− recipients challenged with Escherichia coli expressing ovalbumin (OVA) fused to a cyan fluorescent protein (CFP). After colonization of CX3CR1GFP/+ × RAG−/− animals with red fluorescent E. coli pCherry-OVA, colonic CX3CR1+ cells but not CD103+ DCs phagocytosed E. coli pCherry-OVA. Degraded bacterial-derived antigens are transported by CD103+ DCs to mesenteric lymph nodes (MLNs), where CD103+ DCs prime naive T cells. In RAG−/− recipients reconstituted with OT II cells and gavaged with OVA-expressing E. coli, colonic CX3CR1+ phagocytes are in close contact with CD4 T cells and presented bacterial-derived antigens to CD4 T cells to activate and expand effector T cells. [ABSTRACT FROM AUTHOR]