Regulation of in vitro human T cell development through interleukin-7 deprivation and anti-CD3 stimulation.
BACKGROUND
The role of IL-7 and pre-TCR signaling during T cell development has been well characterized in murine but not in human system. We and others have reported that human BM hematopoietic progenitor cells (HPCs) display poor proliferation, inefficient double negative (DN) to double positive (DP) transition and no functional maturation in the in vitro OP9-Delta-like 1 (DL1) culture system.


RESULTS
In this study, we investigated the importance of optimal IL-7 and pre-TCR signaling during adult human T cell development. Using a modified OP9-DL1 culture ectopically expressing IL-7 and Fms-like tyrosine kinase 3 ligand (Flt3L), we demonstrated enhanced T cell precursor expansion. IL-7 removal at various time points during T cell development promoted a slight increase of DP cells; however, these cells did not differentiate further and underwent cell death. As pre-TCR signaling rescues DN cells from programmed cell death, we treated the culture with anti-CD3 antibody. Upon pre-TCR stimulation, the IL-7 deprived T precursors differentiated into CD3+TCRαβ+DP cells and further matured into functional CD4 T cells, albeit displayed a skewed TCR Vβ repertoire.


CONCLUSIONS
Our study establishes for the first time a critical control for differentiation and maturation of adult human T cells from HPCs by concomitant regulation of IL-7 and pre-TCR signaling.
Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL 32610, USA.
Ekta S
ES
Patel
Starlyn
S
Okada
Kevin
K
Hachey
Li-jun
LJ
Yang
Scott K
SK
Durum
Jan S
JS
Moreb
Lung-Ji
LJ
Chang
D000328:Adult; D018952:Antigens, CD34 / Q000276:immunology / Q000378:metabolism*; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects; D017252:CD3 Complex / Q000378:metabolism*; D015704:CD4 Antigens / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects / Q000276:immunology; D019070:Cell Lineage / Q000187:drug effects / Q000276:immunology; D049109:Cell Proliferation / Q000187:drug effects; D018920:Coculture Techniques; D004247:DNA / Q000235:genetics; D005434:Flow Cytometry; D015332:Gene Rearrangement, alpha-Chain T-Cell Antigen Receptor / Q000235:genetics; D015894:Genome, Human / Q000235:genetics; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects; D006801:Humans; D015851:Interleukin-7 / Q000172:deficiency* / Q000494:pharmacology; D007700:Kinetics; D008565:Membrane Proteins / Q000378:metabolism; D018448:Models, Immunological; D010641:Phenotype; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology* / Q000187:drug effects / Q000276:immunology*
D018952:Antigens, CD34; D017252:CD3 Complex; D015704:CD4 Antigens; C508605:IL7 protein, human; D015851:Interleukin-7; D008565:Membrane Proteins; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta; C084881:flt3 ligand protein; D004247:DNA