title: Expression of functional P-selectin glycoprotein ligand 1 on hematopoietic progenitors is developmentally regulated.
abstract: T cell development requires periodic importation of hematopoietic progenitors into the thymus. The receptor-ligand pair P-selectin and P-selectin glycoprotein ligand 1 (PSGL-1) are critically involved in this process. In this study, we examined the expression of functional PSGL-1 on bone marrow hematopoietic progenitors. We demonstrate that functional PSGL-1 is expressed at low levels on hematopoietic stem cells, but upregulated on the cell surface of progenitors that bear other homing molecules known to be important for thymic settling. We found that progenitors able to home to the thymus expressed high levels of PSGL-1 transcripts compared with hematopoietic stem cells. We further demonstrate that hematopoietic progenitors lacking fucosyltransferase 4 and 7 do not express functional PSGL-1, and do not home efficiently to the thymus. These studies provide insight into the developmentally regulated expression of a critical determinant involved in progenitor homing to the thymus.
authors.affiliation: Department of Pathology and Laboratory Medicine, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Dil Afroz
authors.initials: DA
authors.lastname: Sultana
authors.forename: Shirley L
authors.initials: SL
authors.lastname: Zhang
authors.forename: Sarah P
authors.initials: SP
authors.lastname: Todd
authors.forename: Avinash
authors.initials: A
authors.lastname: Bhandoola
mesh_terms: D000818:Animals; D005647:Fucosyltransferases / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D005786:Gene Expression Regulation / Q000235:genetics / Q000276:immunology*; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D051379:Mice; D018345:Mice, Knockout; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology* / Q000378:metabolism
chemical_list: D008562:Membrane Glycoproteins; C084882:P-selectin ligand protein; D005647:Fucosyltransferases