Disruption of T Cell Suppression in Chronic Lymphocytic Leukemia by CD200 Blockade.
Bibliographic record
Abstract
Abstract Suppression of patients’ T-cells is a key event in CLL pathogenesis and was demonstrated to be mediated by direct cell-cell contact of malignant CLL cells with T-cells. CD200 plays a critical role in regulating the immune system and has been shown to be up-regulated on the surface of different tumors including CLL. In this study we addressed the effects of CD200 over-expression on CLL cells on autologous T cells in a mixed lymphocyte reaction system. We used native and CD40 ligand (CD40L)- stimulated CLL cells as antigen-presenting cells (APCs) to expand autologous T cells of 14 patients. T-cell proliferation was analyzed over 3 weeks of in vitro culture. A functional anti- CD200 antibody (1B9) was added to reveal CD200-mediated immunosuppression in the autologous system. Expansion of patient T-cells was assessed by flow cytometry including intracellular staining of FOXP3. Specificity towards CLL-specific antigens was monitored applying fibromodulin derived peptides for detection of specific T-cells by ELISPOT analysis. T-cell proliferation over 3 weeks of in vitro culture was significantly enhanced compared to control cells when using CD40L-stimulated APCs and an anti-CD200 antibody (p=0.0004). CD200 blockade was further shown to stimulate antigen-specific T-cell responses towards the F2 and F4 peptides of the CLL-associated antigen fibromodulin (p=0.04). Finally, the number of CD4+/CD25high/FOXP3+ T cells (Treg) was significantly decreased in CD200 treated mixed lymphocyte reaction (p=0.04). In summary, CD200 blockade may provide therapeutic benefits in CLL by enhancing T-cell expansion, augmenting an antigen-specific T cell response with suppression of regulatory T cells. CD200 seems to be an important immunosuppressive molecule in CLL: by CD200 blockade immune suppression can be overcome by altering tolerance to tumor antigens and deregulation of regulatory T cells. This combination of an immune induction paralleled by a disruption of immunosuppressive factors makes anti-CD200 mAb a powerful tool for future treatment of CLL, possibly in combination with other B cell cytotoxic or immunostimulatory approaches.
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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 | 0.000 |
| 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".