title: Homeobox gene expression profile in human hematopoietic multipotent stem cells and T-cell progenitors: implications for human T-cell development.
abstract: Class I homeobox (HOX) genes comprise a large family of transcription factors that have been implicated in normal and malignant hematopoiesis. However, data on their expression or function during T-cell development is limited. Using degenerated RT-PCR and Affymetrix microarray analysis, we analyzed the expression pattern of this gene family in human multipotent stem cells from fetal liver (FL) and adult bone marrow (ABM), and in T-cell progenitors from child thymus. We show that FL and ABM stem cells are similar in terms of HOX gene expression, but significant differences were observed between these two cell types and child thymocytes. As the most immature thymocytes are derived from immigrated FL and ABM stem cells, this indicates a drastic change in HOX gene expression upon entry into the thymus. Further analysis of HOX-A7, HOX-A9, HOX-A10, and HOX-A11 expression with specific RT-PCR in all thymocyte differentiation stages showed a sequential loss of 3' region HOX-A cluster genes during intrathymic T-cell development and an unexpected expression of HOX-A11, previously not recognized to play a role in hematopoiesis. Also HOX-B3 and HOX-C4 were expressed throughout thymocyte development. Overall, these data provide novel evidence for an important role of certain HOX genes in human T-cell development.
authors.affiliation: Department of Clinical Chemistry, Microbiology and Immunology, Ghent University Hospital, De Pintelaan 185, Ghent B-9000, Belgium.
authors.forename: T
authors.initials: T
authors.lastname: Taghon
authors.forename: K
authors.initials: K
authors.lastname: Thys
authors.forename: M
authors.initials: M
authors.lastname: De Smedt
authors.forename: F
authors.initials: F
authors.lastname: Weerkamp
authors.forename: F J T
authors.initials: FJ
authors.lastname: Staal
authors.forename: J
authors.initials: J
authors.lastname: Plum
authors.forename: G
authors.initials: G
authors.lastname: Leclercq
mesh_terms: D000328:Adult; D002454:Cell Differentiation / Q000235:genetics; D019070:Cell Lineage / Q000235:genetics; D002648:Child; D017931:DNA Primers / Q000737:chemistry; D005333:Fetus; D015870:Gene Expression; D020869:Gene Expression Profiling; D005801:Genes, Homeobox / Q000502:physiology*; D006412:Hematopoietic Stem Cells / Q000378:metabolism*; D006801:Humans; D008099:Liver / Q000166:cytology; D039902:Multipotent Stem Cells / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells / Q000378:metabolism*; D013601:T-Lymphocytes / Q000378:metabolism*; D013950:Thymus Gland / Q000166:cytology
chemical_list: D017931:DNA Primers; D012333:RNA, Messenger