Thymocyte/Splenocyte-Derived CD4+CD25+Treg Stimulated by Anti-CD200R2 Derived Dendritic Cells Suppress Mixed Leukocyte Cultures and Skin Graft Rejection
Bibliographic record
Abstract
BACKGROUND: CD200 delivers immunoregulatory signals following engagement of its receptor, CD200R. A family of CD200Rs (CD200R1-4) has been described. Spleen expresses cell surface CD200R1, while bone marrow shows predominantly expression of cell surface CD200R2/R3. We showed that dendritic cell precursors (DCp) cultured with anti-CD200R2/3 develop the capacity to induce CD4(+)CD25(+) regulatory T cells (Treg) from peripheral lymphocytes. We now characterize DCs involved in induction of antigen-specific Treg from thymocytes or peripheral T cells, and the properties of Treg cells maintained in long-term culture. METHODS: Bone marrow DCp (C3H or BL/6 origin) were cultured for 8 days with GMCSF, IL-4 and anti-CD200R2, or with CD200Fc and a previously described peptide inhibitor of CD200R1 to allow preferential engagement of non-CD200R1 receptors by CD200. Mixed leukocyte cultures (MLCs) were initiated with allogeneic responder lymphocytes/thymocytes (BL/6 or C3H) and mitomycin-c treated DCs to induce Treg. Treg cells were maintained by reculture with DCs derived in the same manner and IL-2, cloned at limiting dilution, and tested for their ability to suppress MLCs and skin graft rejection in vivo. RESULTS: Foxp3(+) CD4(+)CD25(+) Treg were derived from 60-hr thymocyte and splenocyte T cell cultures using both DC populations. Cloned C3H Treg (Foxp3(+)) suppressed both C3H anti-BL/6 reactivity in a fresh MLC and rejection of BL/6 skin allografts in C3H recipients; the converse was true for BL/6 Treg. CONCLUSIONS: We conclude that CD200 triggering of bone-marrow DCs in the absence of CD200R1 engagement induces CD4(+)CD25(+) Treg, and these cloned antigen-specific Treg may have clinical utility.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".