Related Experiment Videos
Using thymus anatomy to dissect T cell repertoire selection
T M Laufer1, L H Glimcher, D Lo
1Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA, 02115, USA.
Seminars in Immunology
|February 10, 1999
Summary
This study proposes a two-step model for T cell development in the thymus. Positive selection by cortical epithelium is followed by negative selection via medullary epithelium and bone marrow cells.
Area of Science:
- Immunology
- Developmental Biology
- Cell Biology
Background:
- T cell development requires positive and negative selection to generate functional lymphocytes.
- Mature T cells must recognize foreign peptides presented by self-major histocompatibility complex class II molecules.
Purpose of the Study:
- To present a novel model for thymic T cell development.
- To delineate the distinct roles of thymic tissues in selection processes.
Main Methods:
- Conceptual modeling of thymocyte selection processes.
- Analysis of thymic tissue phenotypes and their roles in T cell maturation.
Main Results:
- Positive selection of CD4(+) T cells occurs in two distinct temporal and anatomical steps.
- Initial positive selection is mediated by thymic cortical epithelium.
- Subsequent negative selection involves interactions with medullary epithelium and bone marrow-derived antigen-presenting cells.
Conclusions:
- The model emphasizes the distinct roles of thymic cortical and medullary tissues in T cell selection.
- Tissue phenotype is central to guiding thymocyte maturation and ensuring self-tolerance.