title: Down-regulation of the myeloid homeobox protein Hex is essential for normal T-cell development.
abstract: The haematopoietic homeobox gene Hex (also called Prh) is expressed in myeloid cells and B cells but not T cells. To investigate whether Hex levels might play a role in myeloid versus T-cell development, two types of transgenic mouse lines were constructed, each with ectopic expression of Hex in T cells (CD11a/Hex and Lck/Hex). Both these types of transgenic mouse had the same defects in T-cell maturation, indicating that proper T-cell development may be dependent not just on the up-regulation of lymphoid-specific transcriptional regulators but also on the co-ordinated down-regulation of myeloid-specific transcriptional regulators such as Hex. In addition, Hex over-expression significantly increased myeloid progenitor cycling, which may explain its role in retrovirally induced murine leukaemia.
authors.affiliation: Department of Medicine, the Walther Oncology Center, Indiana University Medical Center, Indianapolis, IN 46202, USA.
authors.forename: David L
authors.initials: DL
authors.lastname: Mack
authors.forename: David S
authors.initials: DS
authors.lastname: Leibowitz
authors.forename: Scott
authors.initials: S
authors.lastname: Cooper
authors.forename: Heather
authors.initials: H
authors.lastname: Ramsey
authors.forename: Hal E
authors.initials: HE
authors.lastname: Broxmeyer
authors.forename: Robert
authors.initials: R
authors.lastname: Hromas
mesh_terms: D000818:Animals; D002460:Cell Line / Q000276:immunology; D015536:Down-Regulation / Q000235:genetics / Q000276:immunology*; D005434:Flow Cytometry / Q000379:methods; D015870:Gene Expression / Q000235:genetics / Q000276:immunology; D005801:Genes, Homeobox / Q000235:genetics / Q000276:immunology; D005838:Genotype; D006412:Hematopoietic Stem Cells / Q000276:immunology; D018398:Homeodomain Proteins / Q000235:genetics / Q000276:immunology*; D008231:Lymphopenia / Q000235:genetics / Q000276:immunology; D051379:Mice; D008809:Mice, Inbred C3H; D008822:Mice, Transgenic; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology; D014157:Transcription Factors
chemical_list: C513080:Hhex protein, mouse; D018398:Homeodomain Proteins; D014157:Transcription Factors