title: Wnt-1 and Wnt-4 regulate thymic cellularity.
abstract: Thymic primordium, formed by cells derived from the endoderm, the ectoderm and the neural crest-derived mesenchyme, receive fetal liver derived lymphoid precursors. Reciprocal cell-cell interactions between thymic stromal cells and lymphoid precursors are critical in the expansion and maturation of thymocytes. Transcription factor TCF-1 is critical for the expansion of thymocytes because deletion of TCF-1 results in a significant decrease in the number of thymocytes without affecting the developmental pattern. In this report we show that Wnt-1 and Wnt-4 are expressed in the thymus and the deletion of Wnt-1 or Wnt-4 result in a substantial decrease in the number of thymocytes without affecting the pattern of maturation. Wnt-1 and Wnt-4 both regulate developing thymocytes because a double deficiency results in a significantly greater decrease of immature and mature thymocytes compared to deficiency in either Wnt-1 or Wnt-4.
authors.affiliation: Department of Pediatric Oncology, Dana Farber Cancer Institute, Boston 02115, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Mulroy
authors.forename: Jill A
authors.initials: JA
authors.lastname: McMahon
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Burakoff
authors.forename: Andrew P
authors.initials: AP
authors.lastname: McMahon
authors.forename: Jyoti
authors.initials: J
authors.lastname: Sen
mesh_terms: D029845:Amphibian Proteins; D000818:Animals; D002454:Cell Differentiation / Q000235:genetics; D002455:Cell Division; D002470:Cell Survival; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000502:physiology; D004527:Egg Proteins / Q000096:biosynthesis / Q000235:genetics; D005326:Fetal Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D005804:Genes, Lethal; D051538:Hepatocyte Nuclear Factor 1-alpha; D018655:Lymphocyte Count; D051821:Lymphoid Enhancer-Binding Factor 1; D051379:Mice; D008807:Mice, Inbred BALB C; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D017154:Stromal Cells / Q000166:cytology; D051822:T Cell Transcription Factor 1; D013601:T-Lymphocytes / Q000166:cytology*; D013950:Thymus Gland / Q000166:cytology* / Q000196:embryology; D014157:Transcription Factors / Q000502:physiology; D051153:Wnt Proteins; D051155:Wnt1 Protein; D060508:Wnt3 Protein; D060528:Wnt4 Protein; D029961:Zebrafish Proteins
chemical_list: D029845:Amphibian Proteins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D004527:Egg Proteins; D005326:Fetal Proteins; D051538:Hepatocyte Nuclear Factor 1-alpha; C496488:Hnf1a protein, mouse; D051821:Lymphoid Enhancer-Binding Factor 1; D011506:Proteins; D011518:Proto-Oncogene Proteins; D051822:T Cell Transcription Factor 1; D014157:Transcription Factors; D051153:Wnt Proteins; D051155:Wnt1 Protein; C495246:Wnt1 protein, mouse; D060508:Wnt3 Protein; D060528:Wnt4 Protein; C555582:Wnt4 protein, mouse; C095936:Wnt6 protein, mouse; D029961:Zebrafish Proteins