Related Experiment Videos
CD6: expression during development, apoptosis and selection of human and mouse thymocytes
Nora G Singer1, David A Fox, Tariq M Haqqi
1Case Western Reserve University School of Medicine and Rainbow Babies and Children's Hospital/University Hospitals of Cleveland, Cleveland, OH 44106, USA. ngs@po.cwru.edu
International Immunology
|June 1, 2002
Summary
CD6 (Cluster of Differentiation 6) expression increases during T cell development, aiding thymocyte survival and selection. This suggests CD6-dependent signals are crucial for T cell maturation and functional avidity.
Area of Science:
- Immunology
- Cell Biology
- Developmental Biology
Background:
- CD6 is a surface glycoprotein primarily found on T lineage cells.
- Its co-stimulatory role in mature T cells is known, but its function during thymocyte development remains unclear.
- CD6 ligands on thymic epithelium suggest a role in thymic selection.
Purpose of the Study:
- To investigate the function of CD6 during thymocyte development.
- To determine the developmental regulation of CD6 expression in human and mouse thymocytes.
- To explore the relationship between CD6 expression, thymic selection, and T cell receptor (TCR) avidity.
Main Methods:
- Analysis of CD6 expression levels during thymocyte development in humans and mice.
- Correlation of CD6 expression with selection markers like CD69.
- Investigation of CD2-induced CD6 expression.
- Comparison of CD6 expression in TCR transgenic mice versus wild-type mice following selection.
Main Results:
- CD6 expression is developmentally regulated in human and mouse thymocytes.
- Increased CD6 expression correlates with the selection marker CD69.
- CD2 activation induces CD6 expression on mature and a subset of immature thymocytes resistant to apoptosis.
- CD6 levels increase during selection of double-positive to single-positive thymocytes, especially with heterogeneous TCRs.
- TCR transgenic mice show minimal CD6 increase post-selection, indicating decreased CD6 dependence with higher functional avidity.
Conclusions:
- CD6-dependent signals contribute to thymocyte survival during development.
- CD6 influences the overall functional avidity of thymic selection in both humans and mice.
- The requirement for CD6 co-stimulation decreases as functional avidity increases.