Interleukin‐21 administration to aged mice rejuvenates their peripheral T‐cell pool by triggering <i>de novo</i> thymopoiesis
Bibliographic record
Abstract
The vaccination efficacy in the elderly is significantly reduced compared to younger populations due to thymic involution and age-related intrinsic changes affecting their naïve T-cell compartment. Interleukin (IL)-21 was recently shown to display thymostimulatory properties. Therefore, we hypothesized that its administration to ageing hosts may improve T-cell output and thus restore a competent peripheral T-cell compartment. Indeed, an increase in the production of recent thymic emigrants (RTEs) attributable to intrathymic expansion of early thymic progenitors (ETPs), double-negative (DN), and double-positive (DP) thymocytes as well as thymic epithelial cell (TEC) was observed in recombinant (r)IL-21-treated aged mice. In sharp contrast, no alterations in the frequency of bone marrow (BM)-derived progenitors were detected following rIL-21 administration. Enhanced production of naïve T cells improved the T-cell receptor (TCR) repertoire diversity and re-established a pool of T cells exhibiting higher levels of miR-181a and diminished amounts of the TCR-inhibiting phosphatases SHP-2 and DUSP5/6. As a result, stimulation of T cells derived from rIL-21-treated aged mice displayed enhanced activation of Lck, ZAP-70, and ERK, which ultimately boosted their IL-2 production, CD25 expression, and proliferation capabilities in comparison with T cells derived from control aged mice. Consequently, aged rIL-21-treated mice vaccinated using a tyrosinase-related protein 2 (Trp2)-derived peptide exhibited a substantial delay in B16 tumor growth and improved survival. The results of this study highlight the immunorestorative function of rIL-21 paving its use as a strategy for the re-establishment of effective immunity in the elderly.
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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) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
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".