title: N-glycolylneuraminic acid xenoantigen contamination of human embryonic and mesenchymal stem cells is substantially reversible.
abstract: Human embryonic and mesenchymal stem cell therapies may offer significant benefit to a large number of patients. Recently, however, human embryonic stem cell lines cultured on mouse feeder cells were reported to be contaminated by the xeno-carbohydrate N-glycolylneuraminic acid (Neu5Gc) and considered potentially unfit for human therapy. To determine the extent of the problem of Neu5Gc contamination for the development of stem cell therapies, we investigated whether it also occurs in cells cultured on human feeder cells and in mesenchymal stem cells, what are the sources of contamination, and whether the contamination is reversible. We found that N-glycolylneuraminic acid was present in embryonic stem cells cultured on human feeder cells, correlating with the presence of Neu5Gc in components of the commercial serum replacement culture medium. Similar contamination occurred in mesenchymal stem cells cultured in the presence of fetal bovine serum. The results suggest that the Neu5Gc is present in both glycoprotein and lipid-linked glycans, as detected by mass spectrometric analysis and monoclonal antibody staining, respectively. Significantly, the contamination was largely reversible in the progeny of both cell types, suggesting that decontaminated cells may be derived from existing stem cell lines. Although major complications have not been reported in the clinical trials with mesenchymal stem cells exposed to fetal bovine serum, the immunogenic contamination may potentially be reflected in the viability and efficacy of the transplanted cells and thus bias the published results. Definition of safe culture conditions for stem cells is essential for future development of cellular therapies.
authors.affiliation: Glykos Finland Ltd., Helsinki, Finland.
authors.forename: Annamari
authors.initials: A
authors.lastname: Heiskanen
authors.forename: Tero
authors.initials: T
authors.lastname: Satomaa
authors.forename: Sari
authors.initials: S
authors.lastname: Tiitinen
authors.forename: Anita
authors.initials: A
authors.lastname: Laitinen
authors.forename: Sirkka
authors.initials: S
authors.lastname: Mannelin
authors.forename: Ulla
authors.initials: U
authors.lastname: Impola
authors.forename: Milla
authors.initials: M
authors.lastname: Mikkola
authors.forename: Cia
authors.initials: C
authors.lastname: Olsson
authors.forename: Halina
authors.initials: H
authors.lastname: Miller-Podraza
authors.forename: Maria
authors.initials: M
authors.lastname: Blomqvist
authors.forename: Anne
authors.initials: A
authors.lastname: Olonen
authors.forename: Hanna
authors.initials: H
authors.lastname: Salo
authors.forename: Petri
authors.initials: P
authors.lastname: Lehenkari
authors.forename: Timo
authors.initials: T
authors.lastname: Tuuri
authors.forename: Timo
authors.initials: T
authors.lastname: Otonkoski
authors.forename: Jari
authors.initials: J
authors.lastname: Natunen
authors.forename: Juhani
authors.initials: J
authors.lastname: Saarinen
authors.forename: Jarmo
authors.initials: J
authors.lastname: Laine
mesh_terms: D000906:Antibodies / Q000494:pharmacology; D000918:Antibody Specificity; D015478:Antigens, Heterophile / Q000494:pharmacology*; D001854:Bone Marrow Cells / Q000166:cytology / Q000502:physiology; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D053595:Embryonic Stem Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D005434:Flow Cytometry; D006706:Homeostasis; D006801:Humans; D007150:Immunohistochemistry; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D009438:Neuraminic Acids / Q000276:immunology* / Q000494:pharmacology*; D010641:Phenotype; D011134:Polysaccharides / Q000737:chemistry / Q000302:isolation & purification; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000906:Antibodies; D015478:Antigens, Heterophile; D009438:Neuraminic Acids; D011134:Polysaccharides; C032592:N-glycolylneuraminic acid