Abstract IA008: Altering the T cell receptor repertoire in the sarcoma tumor immune microenvironment
Bibliographic record
Abstract
Abstract Our lab has been interested in characterizing the T cell receptor (TCR) repertoire of sarcoma subtypes as well as characterizing their immune infiltrates and studying the changes that occur on experimental immunotherapies. In this trial, 15 patients with metastatic soft tissue sarcoma STS patients with a superficial injectable lesion were treated weekly with an intratumoral (IT) toll like receptor 4 (TLR4) agonist Glucopyranosyl Lipid Adjuvant (GLA) for 8-12 weeks plus concurrent radiotherapy. Core biopsies and blood were collected pre and post treatment, and immune analysis was performed by T cell receptor (TCR) sequencing and multiplex IHC. RECIST v1.1 and CTCAE guidelines were used to monitor clinical outcomes. No grade 3 or higher treatment-related toxicity was observed, and local tumor control was achieved in 93% (14/15). 6 (40%) had overall stable disease after IT GLA, and one had complete regression of injected tumor. 3 other patients had long term control of injected tumor past 250 days, during which the uninjected STS had progression despite radiation. In patients with durable local control after IT GLA, multiplex IHC demonstrated increased CD4 and CD8 T cell infiltration, as well as decrease in regulatory T cells. In patient #5-6, TCR sequencing revealed 5-fold increase in PBMC clonality, with selective clonal expansion of T cells present in pre-treatment biopsy. In patient #10-6 (local control to 370 days), there was clonal expansion of T cells within TME which were also found in post treatment PBMC; matched single cell sequencing revealed these clones to be CD4 T cells with Th1 gene signatures. In this trial we found that GLA with radiation induced effective local control of superficial, metastatic STS lesion, inducing a shift in the TME towards an inflammatory state with strong infiltration of T cells. There was selective expansion of clones present in pre-treatment TME in circulating PBMC post IT GLA, isolated to be Th1 cells in one patient. This suggests induction of adaptive anti-tumor response, which may further be enhanced by combination with other immunomodulators. Citation Format: Seth M. Pollack, Y. Dave Seo. Altering the T cell receptor repertoire in the sarcoma tumor immune microenvironment [abstract]. In: Proceedings of the AACR Special Conference: Sarcomas; 2022 May 9-12; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2022;28(18_Suppl):Abstract nr IA008.
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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) | 0.004 | 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".