title: Ex vivo glycan engineering of CD44 programs human multipotent mesenchymal stromal cell trafficking to bone.
abstract: The capacity to direct migration ('homing') of blood-borne cells to a predetermined anatomic compartment is vital to stem cell-based tissue engineering and other adoptive cellular therapies. Although multipotent mesenchymal stromal cells (MSCs, also termed 'mesenchymal stem cells') hold the potential for curing generalized skeletal diseases, their clinical effectiveness is constrained by the poor osteotropism of infused MSCs (refs. 1-3). Cellular recruitment to bone occurs within specialized marrow vessels that constitutively express vascular E-selectin, a lectin that recognizes sialofucosylated determinants on its various ligands. We show here that human MSCs do not express E-selectin ligands, but express a CD44 glycoform bearing alpha-2,3-sialyl modifications. Using an alpha-1,3-fucosyltransferase preparation and enzymatic conditions specifically designed for treating live cells, we converted the native CD44 glycoform on MSCs into hematopoietic cell E-selectin/L-selectin ligand (HCELL), which conferred potent E-selectin binding without effects on cell viability or multipotency. Real-time intravital microscopy in immunocompromised (NOD/SCID) mice showed that intravenously infused HCELL(+) MSCs infiltrated marrow within hours of infusion, with ensuing rare foci of endosteally localized cells and human osteoid generation. These findings establish that the HCELL glycoform of CD44 confers tropism to bone and unveil a readily translatable roadmap for programming cellular trafficking by chemical engineering of glycans on a distinct membrane glycoprotein.
authors.affiliation: Department of Dermatology, Brigham and Women's Hospital and Harvard Skin Disease Research Center, Harvard Medical School, Boston, Massachusetts 02115, USA. rsackstein@rics.bwh.harvard.edu
authors.forename: Robert
authors.initials: R
authors.lastname: Sackstein
authors.forename: Jasmeen S
authors.initials: JS
authors.lastname: Merzaban
authors.forename: Derek W
authors.initials: DW
authors.lastname: Cain
authors.forename: Nilesh M
authors.initials: NM
authors.lastname: Dagia
authors.forename: Joel A
authors.initials: JA
authors.lastname: Spencer
authors.forename: Charles P
authors.initials: CP
authors.lastname: Lin
authors.forename: Roland
authors.initials: R
authors.lastname: Wohlgemuth
mesh_terms: D000328:Adult; D000818:Animals; D000911:Antibodies, Monoclonal; D001853:Bone Marrow / Q000187:drug effects; D001842:Bone and Bones / Q000166:cytology* / Q000187:drug effects; D002448:Cell Adhesion / Q000187:drug effects; D002465:Cell Movement; D019040:E-Selectin / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects; D000939:Epitopes; D005643:Fucose / Q000378:metabolism; D005647:Fucosyltransferases / Q000494:pharmacology; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism*; D008024:Ligands; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects; D051379:Mice; D008875:Middle Aged; D039902:Multipotent Stem Cells / Q000166:cytology* / Q000187:drug effects; D019158:N-Acetylneuraminic Acid / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism*; D013314:Stress, Mechanical; D017154:Stromal Cells / Q000166:cytology* / Q000187:drug effects
chemical_list: D000911:Antibodies, Monoclonal; D019040:E-Selectin; D000939:Epitopes; D005643:Fucose; D005647:Fucosyltransferases; D018960:Hyaluronan Receptors; D008024:Ligands; D019158:N-Acetylneuraminic Acid; D011134:Polysaccharides; C515956:FUT6 protein, human; C497483:CD44 protein, human