Related Experiment Videos
TOX provides a link between calcineurin activation and CD8 lineage commitment.
Parinaz Aliahmad1, Emmett O'Flaherty, Peggy Han
1Department of Immunology IMM-8, The Scripps Research Institute, 10550 N. Torrey Pines Rd., La Jolla, CA 92037, USA.
The Journal of Experimental Medicine
|April 14, 2004
Summary
The HMG box protein TOX drives T cell development by altering coreceptor gene expression and initiating CD8 lineage selection, independent of typical T cell receptor signals. This process involves Runx3 up-regulation and calcineurin signaling.
Area of Science:
- Immunology
- Molecular Biology
- Cellular Biology
Background:
- T cell development requires integrating multiple signaling pathways.
- Few links are known between signaling cascades and nuclear factors in thymocyte differentiation.
Purpose of the Study:
- To investigate the role of the HMG box protein TOX in T cell development.
- To identify downstream nuclear factors and signaling pathways involved in thymocyte differentiation.
Main Methods:
- Assessing the effects of TOX expression on coreceptor gene expression.
- Analyzing CD8 gene demethylation and CD4 silencing.
- Investigating the role of calcineurin signaling in TOX up-regulation.
Main Results:
- TOX expression induces changes in coreceptor gene expression, including CD8 gene demethylation.
- TOX initiates CD8 lineage positive selection independently of MHC-TCR interactions.
- TOX up-regulation is calcineurin-dependent and linked to Runx3 up-regulation and CD4 silencing.
Conclusions:
- TOX is a key nuclear factor in T cell development, influencing coreceptor expression and lineage commitment.
- Calcineurin signaling is critical for TOX up-regulation during positive selection, linking signaling pathways to nuclear events.
- TOX plays a significant role in CD8 lineage commitment, with potential implications for understanding T cell differentiation defects.