title: HLA Class I Depleted hESC as a Source of Hypoimmunogenic Cells for Tissue Engineering Applications.
abstract: BACKGROUND
  Rapidly improving protocols for the derivation of autologous cells from stem cell sources is a welcome development. However, there are many circumstances when off-the-shelf universally immunocompatible cells may be needed. Embryonic stem cells (ESCs) provide a unique opportunity to modify the original source of differentiated cells to minimize their rejection by nonautologous hosts.
  
  
  OBJECTIVE
  Immune rejection of nonautologous human embryonic stem cell (hESC) derivatives can be reduced by downregulating human leukocyte antigen (HLA) class I molecules, without affecting the ability of these cells to differentiate into specific lineages.
  
  
  RESULTS
  Beta-2-microglobulin (B2M) expression was decreased by lentiviral transduction using human anti-HLA class I light-chain B2M short hairpin RNA. mRNA levels of B2M were decreased by 90% in a RUES2-modified hESC line, as determined by quantitative real time-polymerase chain reaction analysis. The transduced cells were selected under puromycin pressure and maintained in an undifferentiated state. The latter was confirmed by Oct4 and Nanog expression, and by the formation of characteristic round-shaped colonies. B2M downregulation led to diminished HLA-I expression on the cell surface, as determined by flow cytometry. When used as target cells in a mixed lymphocyte reaction assay, transduced hESCs and their differentiated derivatives did not stimulate allogeneic T-cell proliferation. Using a cardiac differentiation protocol, transduced hESCs formed a confluent layer of cardiac myocytes and maintained a low level of B2M expression. Transduced hESCs were also successfully differentiated into a hepatic lineage, validating their capacity to differentiate into multiple lineages.
  
  
  CONCLUSIONS
  HLA-I depletion does not preclude hESC differentiation into cardiac or hepatic lineages. This methodology can be used to engineer tissue from nonautologous hESC sources with improved immunocompatibility.
authors.affiliation: 1 Pharmacology and Physiology Department, School of Medicine and Health Sciences, The George Washington University , Washington, District of Columbia.|2 L.A.Orbeli Institute of Physiology, National Academy of Sciences , Yerevan, Armenia .
authors.forename: Zaruhi
authors.initials: Z
authors.lastname: Karabekian
authors.affiliation: 1 Pharmacology and Physiology Department, School of Medicine and Health Sciences, The George Washington University , Washington, District of Columbia.
authors.forename: Hao
authors.initials: H
authors.lastname: Ding
authors.affiliation: 3 Department of Biomedical Engineering, University of California Davis , Davis, California.
authors.forename: Gulnaz
authors.initials: G
authors.lastname: Stybayeva
authors.affiliation: 1 Pharmacology and Physiology Department, School of Medicine and Health Sciences, The George Washington University , Washington, District of Columbia.
authors.forename: Irina
authors.initials: I
authors.lastname: Ivanova
authors.affiliation: 1 Pharmacology and Physiology Department, School of Medicine and Health Sciences, The George Washington University , Washington, District of Columbia.
authors.forename: Narine
authors.initials: N
authors.lastname: Muselimyan
authors.affiliation: 3 Department of Biomedical Engineering, University of California Davis , Davis, California.
authors.forename: Amranul
authors.initials: A
authors.lastname: Haque
authors.affiliation: 1 Pharmacology and Physiology Department, School of Medicine and Health Sciences, The George Washington University , Washington, District of Columbia.
authors.forename: Ian
authors.initials: I
authors.lastname: Toma
authors.affiliation: 1 Pharmacology and Physiology Department, School of Medicine and Health Sciences, The George Washington University , Washington, District of Columbia.
authors.forename: Nikki G
authors.initials: NG
authors.lastname: Posnack
authors.affiliation: 3 Department of Biomedical Engineering, University of California Davis , Davis, California.
authors.forename: Alexander
authors.initials: A
authors.lastname: Revzin
authors.affiliation: 1 Pharmacology and Physiology Department, School of Medicine and Health Sciences, The George Washington University , Washington, District of Columbia.
authors.forename: David
authors.initials: D
authors.lastname: Leitenberg
authors.affiliation: 4 Institute for Stem Cell and Regenerative Medicine, Center for Cardiovascular Biology, University of Washington , Seattle, Washington.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Laflamme
authors.affiliation: 1 Pharmacology and Physiology Department, School of Medicine and Health Sciences, The George Washington University , Washington, District of Columbia.
authors.forename: Narine
authors.initials: N
authors.lastname: Sarvazyan
mesh_terms: D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D049109:Cell Proliferation / Q000502:physiology; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000378:metabolism; D005434:Flow Cytometry; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D039904:Pluripotent Stem Cells / Q000166:cytology* / Q000378:metabolism; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D015395:Histocompatibility Antigens Class I