CD11c(hi) dendritic cells regulate the re-establishment of vascular quiescence and stabilization after immune stimulation of lymph nodes.
Lymph node expansion during immune responses is accompanied by rapid vascular expansion. The re-establishment of quiescence and stabilization of the newly expanded vasculature and the regulatory mechanisms involved have not been well studied. We show that although initiation of vascular expansion in immune-stimulated nodes is associated with upregulated endothelial cell proliferation, increased high endothelial venule trafficking efficiency and VCAM-1 expression, and disrupted perivascular fibroblastic reticular cell organization, the re-establishment of vascular quiescence and stabilization postexpansion is characterized by reversal of these phenomena. Although CD11c(med) cells are associated with the initiation of vascular expansion, CD11c(hi)MHC class II (MHC II)(med) dendritic cells (DCs) accumulate later, and their short-term depletion in mice abrogates the re-establishment of vascular quiescence and stabilization. CD11c(hi)MHC II(med) cells promote endothelial cell quiescence in vitro and, in vivo, mediate quiescence at least in part by mediating reduced lymph node vascular endothelial growth factor. Disrupted vascular quiescence and stabilization in expanded nodes is associated with attenuated T cell-dependent B cell responses. These results describe a novel mechanism whereby CD11c(hi)MHC II(med) DCs regulate the re-establishment of vascular quiescence and stabilization after lymph node vascular expansion and suggest that these DCs function in part to orchestrate the microenvironmental alterations required for successful immunity.
Tzeng
Te-Chen
TC
Department of Pediatric Rheumatology, Hospital for Special Surgery, Weill Medical College of Cornell University, New York, NY 1002, USA.
Chyou
Susan
S
Tian
Sha
S
Webster
Brian
B
Carpenter
April C
AC
Guaiquil
Victor H
VH
Lu
Theresa T
TT
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism; D039521:CD11c Antigen / Q000096:biosynthesis / Q000502:physiology*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000276:immunology; D049109:Cell Proliferation; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D005347:Fibroblasts / Q000276:immunology / Q000378:metabolism; D000949:Histocompatibility Antigens Class II / Q000096:biosynthesis*; D008198:Lymph Nodes / Q000098:blood supply* / Q000166:cytology / Q000276:immunology*; D042601:Lymphatic Vessels / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D021381:Protein Transport / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D015854:Up-Regulation / Q000276:immunology
D039521:CD11c Antigen; D000949:Histocompatibility Antigens Class II