title: The preTCR-dependent DN3 to DP transition requires Notch signaling, is improved by CXCL12 signaling and is inhibited by IL-7 signaling.
abstract: The requirement for Notch signaling during T-cell development has been extensively studied. Nevertheless, the developmental stage at which it is required and whether additional signaling pathways are needed are still poorly understood. By using a stromal-cell-free culture system, we show that sorted double-negative 3 (DN3) thymocytes only require a Delta-like-4-induced Notch signal to differentiate into double-positive (DP) cells. This differentiation process is preTCR-α dependent. DN3 cells undergo 4-5 proliferation cycles, and the addition of the chemokine CXCL12 improves proliferation. IL-7 blocks the differentiation of DN3 cells to DP cells but not the Notch-induced proliferation of cultured DN3 cells. The impaired differentiation correlates with an inhibition of Rag-2 up-regulation. Overall, the in vitro stromal-cell-free culture system presented here also provides a powerful and unique tool for studying the mechanisms involved in the positive and negative selection of T cells.
authors: Developmental and Molecular Immunology, Department of Biomedicine, University of Basel, Basel, Switzerland.
authors: Roxane
authors: R
authors: Tussiwand
authors: Corinne
authors: C
authors: Engdahl
authors: Nadine
authors: N
authors: Gehre
authors: Nabil
authors: N
authors: Bosco
authors: Rod
authors: R
authors: Ceredig
authors: Antonius G
authors: AG
authors: Rolink
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D002135:Calcium-Binding Proteins; D002454:Cell Differentiation / Q000276:immunology*; D002469:Cell Separation; D054377:Chemokine CXCL12 / Q000276:immunology* / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D015851:Interleukin-7 / Q000276:immunology* / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000276:immunology* / Q000378:metabolism; D008565:Membrane Proteins / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D060888:Real-Time Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000276:immunology / Q000378:metabolism; D015398:Signal Transduction / Q000276:immunology*; D060168:Thymocytes / Q000166:cytology* / Q000276:immunology / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002135:Calcium-Binding Proteins; D054377:Chemokine CXCL12; C515256:Cxcl12 protein, mouse; C519665:DLL4 protein, mouse; D015851:Interleukin-7; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D011994:Recombinant Proteins