The preTCR-dependent DN3 to DP transition requires Notch signaling, is improved by CXCL12 signaling and is inhibited by IL-7 signaling

Eur J Immunol. 2011 Nov;41(11):3371-80. doi: 10.1002/eji.201141824. Epub 2011 Oct 4.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium-Binding Proteins
  • Cell Differentiation / immunology*
  • Cell Separation
  • Chemokine CXCL12 / immunology*
  • Chemokine CXCL12 / metabolism
  • Female
  • Flow Cytometry
  • Interleukin-7 / immunology*
  • Interleukin-7 / metabolism
  • Intracellular Signaling Peptides and Proteins / immunology*
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Membrane Proteins / immunology*
  • Membrane Proteins / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Real-Time Polymerase Chain Reaction
  • Recombinant Proteins / immunology
  • Recombinant Proteins / metabolism
  • Signal Transduction / immunology*
  • Thymocytes / cytology*
  • Thymocytes / immunology
  • Thymocytes / metabolism

Substances

  • Calcium-Binding Proteins
  • Chemokine CXCL12
  • Cxcl12 protein, mouse
  • DLL4 protein, mouse
  • Interleukin-7
  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • Recombinant Proteins