Related Experiment Videos
The regulation and function of the CD4 coreceptor during T lymphocyte development
1Department of Microbiology and Immunology, University of California at San Francisco 94143-0414, USA.
Current Topics in Microbiology and Immunology
|January 1, 1996
Summary
The CD4 and CD8 coreceptors enhance thymocyte recognition of peptide/MHC. Their down-regulation during T cell development is crucial for proper CD4+ helper and CD8+ cytotoxic T cell differentiation.
Area of Science:
- Immunology
- Developmental Biology
- Molecular Biology
Background:
- CD4 and CD8 coreceptors are critical for T cell development in the thymus.
- Their precise roles in thymocyte selection and lineage commitment are under investigation.
Purpose of the Study:
- To elucidate the developmental function of CD4 and CD8 coreceptors in thymocyte recognition and selection.
- To explore the mechanisms of coreceptor down-regulation and its link to T cell lineage commitment.
Main Methods:
- Review of experimental data involving transgenic and MHC-null mice.
- Analysis of coreceptor expression dynamics during thymocyte positive selection.
Main Results:
- CD4/CD8 coreceptor expression improves thymocyte peptide/MHC recognition efficacy.
- Coreceptor down-regulation and lineage commitment can be stochastic and MHC-independent.
- Appropriate coreceptor expression is essential for positive selection; loss leads to apoptosis.
- Coreceptor down-regulation is coupled to functional commitment, defining helper (CD4+) and cytotoxic (CD8+) T cell phenotypes.
Conclusions:
- The primary function of CD4 and CD8 coreceptors is to enhance thymocyte peptide/MHC recognition.
- Coreceptor down-regulation is intrinsically linked to T cell functional specialization.
- The molecular mechanisms governing coreceptor regulation and coupling remain to be fully elucidated.