Thymic and Extrathymic T Cell Development Pathways Follow Different Rules
Bibliographic record
Abstract
Separation between primary and secondary lymphoid organs is a universal feature in jawed vertebrates. Strikingly, oncostatin M (OM)-transgenic mice present massive extrathymic T cell development, localized exclusively in the lymph nodes (LN). According to the prevailing paradigm, the thymus is the main source of T lymphocytes in gnathostomes mainly because thymic epithelial cells have a unique ability to support early steps in T cell development. It is therefore remarkable that productive T cell development occurs in the OM(+) LN, despite the absence of epithelial cells. The present study shows that in the OM(+) LN: 1) MHC class I expression strictly on hemopoietic cells is sufficient to support the development of a diversified repertoire of CD8 T cells; 2) the efficiency of positive selection of specific TCR-transgenic T cells is not the same as in the thymus; 3) negative selection is very effective, despite the lack of an organized thymic-like medulla. Furthermore, our data suggest that extrathymic T lymphocytes developing in the OM(+) LN undergo extensive postselection expansion because they live in the microenvironment in which they were positively selected. This work illustrates how the division of labor between primary and secondary lymphoid organs influences the repertoire and homeostasis of T lymphocytes.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".