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Visualizing Antigen Specific CD4+ T Cells using MHC Class II Tetramers
Published on: March 6, 2009
A molecular map of T cell development
D B Sant'Angelo1, B Lucas, P G Waterbury
1Section of Immunology, Yale University School of Medicine, Howard Hughes Medical Institute, New Haven, Connecticut 06520-8011, USA. derek.santangelo@yale.edu
Using a sensitive molecular marker for positive selection, the appearance of a particular functional TCR alpha chain sequence in cells from mice bearing a transgenic beta chain, we address several aspects of intrathymic T cell development. First, by examining specific TCR prior to and after maturation, we demonstrate how a restricted TCR repertoire is positively selected from a highly diverse immature TCR repertoire. Second, since this molecular marker is enriched in cells progressing toward the CD4 lineage and depleted in cells progressing toward the CD8 lineage, a map of the developmental pathway of alphabeta thymocytes can be inferred. Third, the first cells that show clear signs of positive intrathymic selection are identified.
Using a sensitive molecular marker for positive selection, the appearance of a particular functional TCR alpha chain sequence in cells from mice bearing a transgenic beta chain, we address several aspects of intrathymic T cell development. First, by examining specific TCR prior to and after maturation, we demonstrate how a restricted TCR repertoire is positively selected from a highly diverse immature TCR repertoire. Second, since this molecular marker is enriched in cells progressing toward the CD4 lineage and depleted in cells progressing toward the CD8 lineage, a map of the developmental pathway of alphabeta thymocytes can be inferred. Third, the first cells that show clear signs of positive intrathymic selection are identified.

