title: Distinct roles of lymphotoxin-beta signaling and the homeodomain transcription factor Nkx2.3 in the ontogeny of endothelial compartments in spleen.
abstract: The formation of peripheral lymphoid tissues is indispensable for the efficient recognition and elimination of external antigens by lymphoid and accessory cells of the adaptive immune system. The spleen is structurally arranged around various vascular beds with distinct endothelial phenotypes. Using immunohistochemistry, we investigated the postnatal developmental characteristics of the marginal sinus and its relationship with various red-pulp sinus subsets. We also determined the importance of the lymphotoxin beta receptor (LT beta R) and the role of the Nkx2.3 transcription factor for the formation of the splenic vasculature. Both the administration of soluble LT beta R-Ig fusion protein to neonates and the deletion of LT beta R or downstream signaling components (RelB and p52) of the NF-kappaB family inhibited the phenotypic maturation of marginal sinus but had no effect on the vascular compartmentalization of the red pulp. The integrity of the marginal sinus and the proper vascular segregation of the red pulp appeared to be controlled by Nkx2.3, as Nkx2.3-deficient mice exhibited an abnormal distribution of IBL-7/1(hi)/IBL-9/2(-) sinuses and a lack of IBL-7/1(lo)/IBL-9/2(+) vessels. Our data suggest that phenotypic heterogeneity among different vascular elements within distinct anatomical regions of the spleen differentially depends on developmental factors such as lymphotoxin signaling or Nkx2.3, whereas the marginal sinus is controlled by both pathways.
authors.affiliation: Department of Immunology and Biotechnology, Faculty of Medicine, University of Pécs, Szigeti út 12., H-7624, Pécs, Hungary. peter.balogh@aok.pte.hu
authors.forename: Péter
authors.initials: P
authors.lastname: Balogh
authors.forename: Mercedesz
authors.initials: M
authors.lastname: Balázs
authors.forename: Tamás
authors.initials: T
authors.lastname: Czömpöly
authors.forename: Debra S
authors.initials: DS
authors.lastname: Weih
authors.forename: Hans-Henning
authors.initials: HH
authors.lastname: Arnold
authors.forename: Falk
authors.initials: F
authors.lastname: Weih
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics; D004730:Endothelium, Vascular / Q000166:cytology* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D053259:Lymphotoxin beta Receptor / Q000235:genetics; D053308:Lymphotoxin-beta / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D018345:Mice, Knockout; D016513:Mice, SCID; D008954:Models, Biological; D009088:Mucoproteins; D015398:Signal Transduction / Q000502:physiology; D013154:Spleen / Q000098:blood supply* / Q000166:cytology / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*
chemical_list: D015815:Cell Adhesion Molecules; D018398:Homeodomain Proteins; D053259:Lymphotoxin beta Receptor; D053308:Lymphotoxin-beta; C489082:Madcam1 protein, mouse; D009088:Mucoproteins; C522706:Nkx2.3 protein, mouse; D014157:Transcription Factors