title: Visualization of lymphotoxin-beta and lymphotoxin-beta receptor expression in mouse embryos.
abstract: The heteromeric lymphotoxin alphabeta ligand (LT) binds to the LTbeta receptor (LTbetaR) and provides an essential trigger for lymph node (LN) development. LTbetaR signaling is also critical for the emergence of pathological ectopic lymph node-like structures and the maintenance of an organized splenic white pulp. To better understand the role of LT in development, the expression patterns of LTbeta and LTbetaR mRNA were examined by in situ hybridization in the developing mouse embryo. Images of LTbeta ligand expression in developing peripheral LN in the E18.5 embryo revealed a relatively early phase structure and allowed for comparative staging with LN development in rat and humans. The LTbetaR is expressed from E16.5 onward in respiratory, salivary, bronchial, and gastric epithelium, which may be consistent with early communication events between lymphoid elements and epithelial specialization over emerging mucosal LN. Direct comparison of mouse fetal and adult tissues by FACS analysis confirmed the elevated expression of LTBR in some embryonic epithelial layers. Therefore, surface LTBR expression may be elevated during fetal development in some epithelial layers.
authors: Department of Exploratory Biology, Biogen, 12 Cambridge Center, Cambridge, MA 02142, USA. jeff_browning@biogen.com
authors: Jeffrey L
authors: JL
authors: Browning
authors: Lars E
authors: LE
authors: French
mesh_terms: D000375:Aging / Q000235:genetics / Q000276:immunology; D000818:Animals; D004622:Embryo, Mammalian / Q000033:anatomy & histology / Q000276:immunology* / Q000378:metabolism*; D004848:Epithelium / Q000196:embryology / Q000276:immunology / Q000378:metabolism; D005786:Gene Expression Regulation / Q000276:immunology; D008099:Liver / Q000196:embryology / Q000276:immunology / Q000378:metabolism; D008198:Lymph Nodes / Q000196:embryology / Q000276:immunology / Q000378:metabolism; D053259:Lymphotoxin beta Receptor; D008233:Lymphotoxin-alpha / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D053308:Lymphotoxin-beta; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D051379:Mice; D009928:Organ Specificity / Q000235:genetics / Q000276:immunology; D010581:Peyer's Patches / Q000196:embryology / Q000276:immunology / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D018124:Receptors, Tumor Necrosis Factor / Q000096:biosynthesis* / Q000235:genetics; D012867:Skin / Q000196:embryology / Q000276:immunology / Q000378:metabolism; D013950:Thymus Gland / Q000196:embryology / Q000276:immunology / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: C505887:Ltb protein, mouse; C505888:Ltb protein, rat; C505699:Ltbr protein, mouse; D053259:Lymphotoxin beta Receptor; D008233:Lymphotoxin-alpha; D053308:Lymphotoxin-beta; D008565:Membrane Proteins; D012333:RNA, Messenger; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha