title: Human CD8 T cells generated in vitro from hematopoietic stem cells are functionally mature.
abstract: BACKGROUND
  T cell development occurs within the highly specialized thymus. Cytotoxic CD8 T cells are critical in adaptive immunity by targeting virally infected or tumor cells. In this study, we addressed whether functional CD8 T cells can be generated fully in vitro using human umbilical cord blood (UCB) hematopoietic stem cells (HSCs) in coculture with OP9-DL1 cells.
  
  
  RESULTS
  HSC/OP9-DL1 cocultures supported the differentiation of CD8 T cells, which were TCR/CD3(hi) CD27(hi) CD1a(neg) and thus phenotypically resembled mature functional CD8 single positive thymocytes. These in vitro-generated T cells also appeared to be conventional CD8 cells, as they expressed high levels of Eomes and low levels of Plzf, albeit not identical to ex vivo UCB CD8 T cells. Consistent with the phenotypic and molecular characterization, upon TCR-stimulation, in vitro-generated CD8 T cells proliferated, expressed activation markers (MHC-II, CD25, CD38), secreted IFN-γ and expressed Granzyme B, a cytotoxic T-cell effector molecule.
  
  
  CONCLUSIONS
  Taken together, the ability to direct human hematopoietic stem cell or T-progenitor cells towards a mature functional phenotype raises the possibility of establishing cell-based treatments for T-immunodeficiencies by rapidly restoring CD8 effector function, thereby mitigating the risks associated with opportunistic infections.
authors.affiliation: Department of Immunology, University of Toronto, and Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada.
authors.forename: Génève
authors.initials: G
authors.lastname: Awong
authors.forename: Elaine
authors.initials: E
authors.lastname: Herer
authors.forename: Ross N
authors.initials: RN
authors.lastname: La Motte-Mohs
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Zúñiga-Pflücker
mesh_terms: D015703:Antigens, CD / Q000096:biosynthesis; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D002460:Cell Line; D018920:Coculture Techniques; D005312:Fetal Blood / Q000166:cytology; D018507:Gene Expression Regulation, Developmental / Q000276:immunology; D053804:Granzymes / Q000235:genetics / Q000378:metabolism; D006412:Hematopoietic Stem Cells / Q000166:cytology; D006801:Humans; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000235:genetics / Q000378:metabolism; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D008213:Lymphocyte Activation; D038041:Lymphopoiesis; D000075722:Promyelocytic Leukemia Zinc Finger Protein; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D017154:Stromal Cells / Q000166:cytology; D020825:T-Box Domain Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*
chemical_list: D015703:Antigens, CD; C491199:EOMES protein, human; D051741:Kruppel-Like Transcription Factors; D000075722:Promyelocytic Leukemia Zinc Finger Protein; D011948:Receptors, Antigen, T-Cell; D020825:T-Box Domain Proteins; C092037:ZBTB16 protein, human; D007371:Interferon-gamma; D053804:Granzymes