Functionally mature CD4 and CD8 TCRalphabeta cells are generated in OP9-DL1 cultures from human CD34+ hematopoietic cells.
Human CD34(+) hematopoietic precursor cells cultured on delta-like ligand 1 expressing OP9 (OP9-DL1) stromal cells differentiate to T lineage cells. The nature of the T cells generated in these cultures has not been studied in detail. Since these cultures do not contain thymic epithelial cells which are the main cell type mediating positive selection in vivo, generation of conventional helper CD4(+) and cytotoxic CD8(+) TCRalphabeta cells is not expected. Phenotypically mature CD27(+)CD1(-) TCRgammadelta as well as TCRalphabeta cells were generated in OP9-DL1 cultures. CD8 and few mature CD4 single-positive TCRalphabeta cells were observed. Mature CD8 single-positive cells consisted of two subpopulations: one expressing mainly CD8alphabeta and one expressing CD8alphaalpha dimers. TCRalphabeta CD8alphaalpha and TCRgammadelta cells both expressed the IL2Rbeta receptor constitutively and proliferated on IL-15, a characteristic of unconventional T cells. CD8alphabeta(+) and CD4(+) TCRalphabeta cells were unresponsive to IL-15, but could be expanded upon TCR stimulation as mature CD8alphabeta(+) and CD4(+) T cells. These T cells had the characteristics of conventional T cells: CD4(+) cells expressed ThPOK, CD40L, and high levels of IL-2 and IL-4; CD8(+) cells expressed Eomes, Runx3, and high levels of granzyme, perforin, and IFN-gamma. Induction of murine or human MHC class I expression on OP9-DL1 cells had no influence on the differentiation of mature CD8(+) cells. Similarly, the presence of dendritic cells was not required for the generation of mature CD4(+) or CD8(+) T cells. These data suggest that positive selection of these cells is induced by interaction between T precursor cells.
Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium.
Stefanie
S
Van Coppernolle
Greet
G
Verstichel
Frank
F
Timmermans
Imke
I
Velghe
David
D
Vermijlen
Magda
M
De Smedt
Georges
G
Leclercq
Jean
J
Plum
Tom
T
Taghon
Bart
B
Vandekerckhove
Tessa
T
Kerre
D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D023201:CD40 Ligand / Q000276:immunology / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D002454:Cell Differentiation / Q000276:immunology*; D002460:Cell Line; D018920:Coculture Techniques; D004268:DNA-Binding Proteins / Q000276:immunology / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism; D006412:Hematopoietic Stem Cells / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D015395:Histocompatibility Antigens Class I / Q000276:immunology / Q000378:metabolism; D006801:Humans; D019409:Interleukin-15 / Q000494:pharmacology; D007376:Interleukin-2 / Q000276:immunology / Q000378:metabolism; D015847:Interleukin-4 / Q000276:immunology / Q000378:metabolism; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology* / Q000378:metabolism; D015375:Receptors, Interleukin-2 / Q000276:immunology / Q000378:metabolism; D014157:Transcription Factors / Q000276:immunology / Q000378:metabolism
D004268:DNA-Binding Proteins; D015395:Histocompatibility Antigens Class I; C508594:IL2 protein, human; C508598:IL4 protein, human; D019409:Interleukin-15; D007376:Interleukin-2; D016693:Receptors, Antigen, T-Cell, alpha-beta; D015375:Receptors, Interleukin-2; D014157:Transcription Factors; C484225:ZBTB7B protein, human; D023201:CD40 Ligand; D015847:Interleukin-4