title: The i blood group antigen as a marker for umbilical cord blood-derived mesenchymal stem cells.
abstract: Multipotent mesenchymal stem cells (MSCs) offer great promise for future regenerative and anti-inflammatory therapies. However, there is a lack of methods to quickly and efficiently isolate, characterize, and ex vivo expand desired cell populations for therapeutic purposes. Single markers to identify cell populations have not been characterized; instead, all characterizations rely on panels of functional and phenotypical properties. Glycan epitopes can be used for identifying and isolating specific cell types from heterogeneous populations, on the basis of their cell-type specific expression and prominent cell surface localization. We have now studied in detail the cell surface expression of the blood group i epitope (linear poly-N-acetyllactosamine chain) in umbilical cord blood (UCB)-derived MSCs. We used flow cytometry and mass spectrometric glycan analysis and discovered that linear poly-N-acetyllactosamine structures are expressed in UCB-derived MSCs, but not in cells differentiated from them. We further verified the findings by mass spectrometric glycan analysis. Gene expression analysis indicated that the stem-cell specific expression of the i antigen is determined by β3-N-acetylglucosaminyltransferase 5. The i antigen is a ligand for the galectin family of soluble lectins. We found concomitant cell surface expression of galectin-3, which has been reported to mediate the immunosuppressive effects exerted by MSCs. The i antigen may serve as an endogenous ligand for this immunosuppressive agent in the MSC microenvironment. Based on these findings, we suggest that linear poly-N-acetyllactosamine could be used as a novel UCB-MSC marker either alone or within an array of MSC markers.
authors.affiliation: Department of Advanced Therapy and Product Development, Finnish Red Cross Blood Service, Helsinki, Finland.
authors.forename: Tia
authors.initials: T
authors.lastname: Hirvonen
authors.forename: Heli
authors.initials: H
authors.lastname: Suila
authors.forename: Annika
authors.initials: A
authors.lastname: Kotovuori
authors.forename: Ilja
authors.initials: I
authors.lastname: Ritamo
authors.forename: Annamari
authors.initials: A
authors.lastname: Heiskanen
authors.forename: Pertti
authors.initials: P
authors.lastname: Sistonen
authors.forename: Heidi
authors.initials: H
authors.lastname: Anderson
authors.forename: Tero
authors.initials: T
authors.lastname: Satomaa
authors.forename: Juhani
authors.initials: J
authors.lastname: Saarinen
authors.forename: Sari
authors.initials: S
authors.lastname: Tiitinen
authors.forename: Jarkko
authors.initials: J
authors.lastname: Räbinä
authors.forename: Saara
authors.initials: S
authors.lastname: Laitinen
authors.forename: Suvi
authors.initials: S
authors.lastname: Natunen
authors.forename: Leena
authors.initials: L
authors.lastname: Valmu
mesh_terms: D000606:Amino Sugars / Q000378:metabolism; D015415:Biomarkers / Q000032:analysis; D002454:Cell Differentiation; D000939:Epitopes / Q000737:chemistry; D005312:Fetal Blood / Q000166:cytology* / Q000378:metabolism; D005434:Flow Cytometry; D037502:Galectin 3 / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D006801:Humans; D007048:I Blood-Group System / Q000378:metabolism*; D008024:Ligands; D013058:Mass Spectrometry; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics; D055153:Stem Cell Niche
chemical_list: D000606:Amino Sugars; D015415:Biomarkers; D000939:Epitopes; D037502:Galectin 3; D007048:I Blood-Group System; D008024:Ligands; C000458:N-acetyllactosamine; D017351:N-Acetylglucosaminyltransferases