thymocyte
thymo.site · being built
| What it is | A developing T cell in the thymus, tested on its receptor in the cortex, where most die and a few mature. |
|---|---|
| Comes from | Hematopoietic stem cell |
| About | In the adult thymus most thymocytes are at a non-proliferating end stage in which 3 percent of CD4+CD8+ cortical thymocytes are selected to become mature thymocytes and the 97 percent unselected die in the thymus, after about two weeks of proliferation giving a 10^5-fold expansion from the hundred prothymocytes that seed the thymus each day. |
| Source | Shortman K, Egerton M, Spangrude GJ, Scollay R. The generation and fate of thymocytes. Semin Immunol. 1990;2(1):3-12. PMID: 2129900 |
| Status | being built; its twin, knowledge and helper come with thymo.site |
Where it lives
| The thymic cortex, heavily populated by developing T cells among fewer epithelial cells | several · PMID 17067941 |
| The medulla once mature, larger, among abundant epithelial cells | several · PMID 17067941 |
| A thymus that keeps a median 19.5 cm3 through life while its epithelial space involutes from the first year | human · PMID 4081647 |
What it does
| Expands 10^5-fold over two weeks from the hundred prothymocytes seeding the thymus a day | mouse · PMID 2129900 |
| Matures one for one from a non-dividing cortical pool, at 3 percent of the double positive production rate | mouse · PMID 2138780 |
What goes wrong
| 97 percent of double positive thymocytes die in the thymus, unselected or rejected | mouse · PMID 2129900 |