Related Experiment Video
Updated: Jun 27, 2026
Characterization of Thymic Settling Progenitors in the Mouse Embryo Using In Vivo and In Vitro Assays
Published on: June 9, 2015
[Cloning deletion of mouse medullary CD4SP thymocyte subgroups induced by superantigen staphylococcal enterotoxin B]
Juan Li1, Yu Bin Zhou, Yu Zhang
1Department of Immunology, Peking University School of Basic Medical Sciences, Beijing, China.
Objective:
To investigate the clonal deletion of medullary CD4SP thymocyte subgroups induced by superantigen SEB, and to understand the stage specificity of thymic negative selection based on the developmental pathway of medullary CD4SP thymocytes we established previously.
Methods:
SEB was intravenously injected into C57BL/6 mice, and then the expression of surface molecules and apoptosis of thymocytes were detected by FACS. The reduction of each subgroup of medullary CD4SP thymocytes was analyzed by FACS assay and cell counting.
Results:
The percentage of apoptotic CD4SP thymocytes significantly increased after the intravenous injection of SEB. The cell number of CD4SP decreased about 43.8%. Among TCR Vbeta8(+)CD4SP thymocytes, the percentage of 6C10(+)CD69(+)Qa-2(-)thymocytes(SP1) was reduced by two thirds and the percentage of Qa-2(+) thymocytes(SP4) was comparatively increased, while the cell numbers of SP1 to SP3 decreased over 80% and that of SP4 decreased about 50%.
Conclusion:
Thymic negative selection occurs during the stage of SP and goes through the whole developmental progress from SP1 to SP4.The thymocytes in the stage of SP1 to SP3 are more sensitive to apoptosis than those in the stage of SP4.
Insights
Superantigen SEB induces thymic negative selection in CD4SP thymocytes, with earlier developmental stages (SP1-SP3) being more susceptible to apoptosis than later stages (SP4). This highlights stage-specific sensitivity during T-cell development.
Area of Science:
- Immunology
- T-cell development
- Thymic selection
Context:
- Medullary CD4SP thymocyte development is crucial for self-tolerance.
- Superantigens like SEB can trigger T-cell receptor-mediated responses.
- Understanding thymic negative selection is key to immune regulation.
Purpose:
- To investigate the clonal deletion of medullary CD4SP thymocyte subgroups induced by superantigen SEB.
- To determine the stage specificity of thymic negative selection.
- To analyze the developmental pathway of medullary CD4SP thymocytes.
Summary:
- SEB injection in mice led to increased apoptosis of CD4SP thymocytes.
- Significant reductions were observed in thymocyte subpopulations SP1-SP3 (over 80%) and SP4 (about 50%).
- Thymic negative selection occurs throughout SP development (SP1-SP4), with SP1-SP3 stages showing higher sensitivity to apoptosis.
Impact:
- Provides insights into the stage-specific mechanisms of thymic negative selection.
- Identifies differential sensitivity of thymocyte subsets to superantigen-induced apoptosis.
- Contributes to understanding T-cell repertoire selection and potential autoimmune disease mechanisms.
