title: Chemokine-mediated thymopoiesis is regulated by a mammalian Polycomb group gene, mel-18.
abstract: Multiple chemokines are made in the thymus, and they are likely to function in the fine control of cellular migration and regulation of thymic T cell development. Mice lacking the gene mel-18, a member of the mammalian Polycomb group genes, displayed impaired thymic T cell development. Here we report that expression of chemokine receptors CXCR4 and CCR9 are regulated by mel-18 and that CXCL12/SDF-1- and CCL25/TECK-mediated chemotactic activities are also affected by the loss of mel-18. In mel-18-/- mice, high expression of CXCR4 on CD4-CD8- cells might lead to trapping in the SDF-1 rich subcapsular region, while low expression of CCR9 on CD4+CD8+ cells might reduce cell migration to the medulla. Therefore, this member of the Polycomb group genes plays a role in thymic T cell migration and differentiation via the chemokine system.
authors.affiliation: Department of Immunology and Parasitology, Faculty of Medicine, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima 734-8551, Japan.
authors.forename: Kozue
authors.initials: K
authors.lastname: Miyazaki
authors.forename: Hiroko
authors.initials: H
authors.lastname: Inoue
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Onai
authors.forename: Hiroto
authors.initials: H
authors.lastname: Ishihara
authors.forename: Masamoto
authors.initials: M
authors.lastname: Kanno
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002465:Cell Movement; D018925:Chemokines / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D005434:Flow Cytometry; D017353:Gene Deletion; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D063150:Polycomb Repressive Complex 1; D063146:Polycomb-Group Proteins; D019707:Receptors, Chemokine / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry*; D013601:T-Lymphocytes / Q000166:cytology* / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology* / Q000378:metabolism*
chemical_list: D018925:Chemokines; D004268:DNA-Binding Proteins; C066476:Pcgf6 protein, mouse; D063146:Polycomb-Group Proteins; D019707:Receptors, Chemokine; D012097:Repressor Proteins; D063150:Polycomb Repressive Complex 1