title: MAdCAM-1 dependent colonization of developing lymph nodes involves a unique subset of CD4+CD3- hematolymphoid cells.
abstract: During fetal lymph node organogenesis in mice, lymph node postcapillary high endothelial venules briefly express the Peyer's patch addressin MAdCAM-1. This allows initial seeding by two unusual lymphocyte populations selectively expressing the Peyer's patch homing receptor integrin alpha4beta 7: CD4+CD3- oligolineage progenitors and TCR gammadelta+ T cells. It was found that the CD4+CD3- cells are lineage-restricted progenitors that express surface lymphotoxin-beta (LTbeta) and the chemokine receptor BLR1. They can differentiate into natural killer cells, dendritic antigen-presenting cells, and follicular cells of unknown outcome, but these cells do not become T or B lymphocytes. In addition to LN, CD4+CD3- cells can also be found in fetal spleen starting at 13.5 dpc, while absent from fetal liver. In view of the necessity of lymphotoxin in lymphoid organ development, it is thought that the novel subset of CD4+CD3- LTbeta+ fetal cells is instrumental in the development of lymphoid tissue architecture.
authors.affiliation: Department of Cell Biology and Immunology, Faculty of Medicine, Vrije Universiteit, Amsterdam, The Netherlands. R.Mebius.Cell@med.vu.nl
authors.forename: R E
authors.initials: RE
authors.lastname: Mebius
authors.forename: I L
authors.initials: IL
authors.lastname: Schadee-Eestermans
authors.forename: I L
authors.initials: IL
authors.lastname: Weissman
mesh_terms: D000818:Animals; D017252:CD3 Complex / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000737:chemistry / Q000276:immunology*; D002465:Cell Movement / Q000276:immunology*; D006412:Hematopoietic Stem Cells / Q000737:chemistry / Q000166:cytology / Q000276:immunology; D007136:Immunoglobulins / Q000276:immunology*; D008198:Lymph Nodes / Q000166:cytology / Q000254:growth & development*; D009088:Mucoproteins / Q000276:immunology*; D016201:Receptors, Lymphocyte Homing / Q000276:immunology
chemical_list: D017252:CD3 Complex; D007136:Immunoglobulins; D009088:Mucoproteins; D016201:Receptors, Lymphocyte Homing