sCD200 Present in Mice Receiving Cardiac and Skin Allografts Causes Immunosuppression In Vitro and Induces Tregs
Bibliographic record
Abstract
BACKGROUND: CD200 overexpression in transgenic mice increases skin, cardiac, and renal allograft survival. Elevated levels of soluble CD200 (sCD200) are found in the serum of cancer individuals. We investigated whether sCD200 levels increase in mice with prolonged graft survival. METHODS: Control or CD200 BL/6 recipients of BALB/c cardiac or skin grafts received low-dose rapamycin (0.5 mg/kg) at 36-hr intervals, a dose shown previously not to augment the survival of control grafts or alter the host antigraft immunity or graft gene expression profiles. Separate groups received high-dose rapamycin (1.5 mg/kg). Serum was obtained at 8, 15, and 80 days after grafting and assayed for sCD200 (enzyme-linked immunosorbent assay), for the suppression of immunity in mixed leukocyte cultures (MLCs), for the induction of regulatory T cells able to suppress cytotoxic T lymphocyte induction in MLCs, and for the ability to transfer graft survival to naïve recipients. RESULTS: Both CD200 and conventional mice with early enhanced graft survival had increased levels of sCD200 in serum, which induced Tr1 able to suppress MLCs. Suppression was abolished after passage of serum over a CD200 immunoadsorbent column. Dendritic cells maturing in the presence of sCD200 serum could induce populations of Foxp3 regulatory T cells able to suppress MLCs in vitro. In CD200 mice with long-term surviving cardiac (skin) allografts in the absence of continued transgene induction (>80 days [>35 days]), sCD200 levels returned to baseline, with no loss of grafts, but sera were unable to suppress MLCs in vitro. sCD200 serum adoptively transferred increased graft survival to naïve mice. CONCLUSION: We conclude that monitoring sCD200 at early times after engraftment may predict allograft survival.
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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 | 0.000 | 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".