Analysis of Notch1 function by in vitro T cell differentiation of Pax5 mutant lymphoid progenitors
Signaling through the Notch1 receptor is essential for T cell development in the thymus. Stromal OP9 cells ectopically expressing the Notch ligand Delta-like1 mimic the thymic environment by inducing hemopoietic stem cells to undergo in vitro T cell development. Notch1 is also expressed on Pax5-/- pro-B cells, which are clonable lymphoid progenitors with a latent myeloid potential. In this study, we demonstrate that Pax5-/- progenitors efficiently differentiate in vitro into CD4+CD8+ alphabeta and gammadelta T cells upon coculture with OP9-Delta-like1 cells. In vitro T cell development of Pax5-/- progenitors strictly depends on Notch1 function and progresses through normal developmental stages by expressing T cell markers and rearranging TCRbeta, gamma, and delta loci in the correct temporal sequence. Notch-stimulated Pax5-/- progenitors efficiently down-regulate the expression of B cell-specific genes, consistent with a role of Notch1 in preventing B lymphopoiesis in the thymus. At the same time, Notch signaling rapidly induces cell surface expression of the c-Kit receptor and transcription of the target genes Deltex1 and pre-Talpha concomitant with the activation of TCR Vbeta germline transcription and the regulatory genes GATA3 and Tcf1. These data suggest that Notch1 acts upstream of GATA3 and Tcf1 in early T cell development and regulates Vbeta-DJbeta rearrangements by controlling the chromatin accessibility of Vbeta genes at the TCRbeta locus.
- URL: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=15356142
Keywords: Animals ; B-Cell-Specific Activator Protein ; B-Lymphocyte Subsets/cytology/metabolism/physiology ; Cell Differentiation/genetics/immunology ; Cell Line ; Cell Lineage/genetics/immunology ; Clone Cells ; Coculture Techniques ; DNA-Binding Proteins/*genetics/physiology ; Down-Regulation/genetics/immunology ; Gene Expression Regulation/immunology ; Mice ; Mice ; Inbred C57BL ; Mice ; Knockout ; *Mutation ; Receptor ; Notch1 ; Receptors ; Antigen ; T-Cell ; alpha-beta/genetics ; Receptors ; Antigen ; T-Cell ; gamma-delta/genetics ; Receptors ; Cell Surface/genetics/*physiology ; Research Support ; Non-U.S. Gov't ; Signal Transduction/genetics/immunology ; Stem Cells/*cytology/*metabolism/physiology ; Stromal Cells/physiology ; T-Lymphocyte Subsets/*cytology/metabolism/*physiology ; Transcription Factors/*genetics/*physiology
Research Institute of Molecular Pathology, Vienna Biocenter, Vienna, Austria.
Record created on 2006-12-05, modified on 2016-08-08