Abstract B078: Developing an all-human preclinical model of PDAC immunoreactivity
Peter A. Azorsa, Molly Goldwasser, Vaibhav Sahai, Nicole Peterson, Jorge D. Machicado, Richard Kwon, Allison R. Schulman, George Phillips, Stacy B. Menees, Erik Wamsteker, Jonathan Y. Xia, Jiaqi Shi, Timothy L. Frankel, Filip Bednar, Marina Pasca Di Magliano, Shannon Carty, Eileen S. CarpenterAbstract
Background:
Pancreatic cancer is one of the deadliest indications in both the United States and the world with an overall 5-year survival rate of 14%. Adoptive cell transfer therapies have seen modest success in solid tumor but there has yet to be a durable response in PDAC. This is largely attributed to the immunosuppressive tumor microenvironment, tumor heterogeneity, and low mutation burden/neoantigen availability. PDAC harbors an especially difficult environment for immune cell activity. Recent developments in patient derived organoids (PDO) allowed for a human model to recapitulate the patient mutanome as well as maintain other characteristics relevant to cancer immunity such as HLA or inhibitory ligand expression. Despite these developments, modeling tumor reactivity via T cells remains difficult in part because of the challenge of matching T-cell receptors to diverse HLA haplotypes and epitopes presented in PDAC models. While TCR-T and antigen models do exist in murine models, namely the OT-I / ovalbumin system, a model comprising of a fully human effector and target has yet to be standardized. Here, we present our development of an all-human in-vitro model for TCR-mediated T cell reactivity against matched PDAC patient derived organoids to elucidate the immunomodulatory effect of pancreatic cancer on a per-patient basis.
Results:
We successfully generated healthy T cells from Gift of Life donor splenocytes with up to 100-fold expansion over 20 days. In addition to expansion, we have also optimized this protocol to improve T cell fitness by implementing IL-2, IL-7, and IL-15 compared to classic expansion protocols utilizing solely IL-2. T cell fitness measured by improved memory phenotype (higher naïve fraction). We have begun transduction protocol set up through the use of the MSGV1 vector and performed a pilot study using a publicly available TCR specific to HPV-E6. We have validated successful transduction of this TCR via flow cytometry with continued TCR expression across a 2-week expansion. For the target model, we performed whole exome sequencing on in-house bio-banked patient derived organoids and identified 51 patients with G12D/G12V mutations. From this group, we chose 3 patients with the A*11:01 allele, 2 patients with the A*03:01 allele and 1 patient with both A*03:01 and C*08:02. We then characterized relative class I HLA expression on all matching patients via flow cytometry in both 3D and 2D organoid culture formats. In addition, we have confirmed, via WES, the continued presence of the G12V and G12D mutations in their respective patients across long term cultures.
Conclusions:
We have successfully generated the necessary components to assay T cell immunoreactivity to organoids by leveraging engineered TCR-Ts and endogenous oncogenic Kras antigen presentation in PDAC organoids. For future studies we will utilize this model system to investigate immunosuppression on a per-patient basis, with the goal of establishing a robust all-human assay platform to test the efficacy of immunotherapeutic agents.
Citation Format:
Peter A. Azorsa, Molly Goldwasser, Vaibhav Sahai, Nicole Peterson, Jorge D. Machicado, Richard Kwon, Allison R. Schulman, George Phillips, Stacy B. Menees, Erik Wamsteker, Jonathan Y. Xia, Jiaqi Shi, Timothy L. Frankel, Filip Bednar, Marina Pasca Di Magliano, Shannon Carty, Eileen S. Carpenter. Developing an all-human preclinical model of PDAC immunoreactivity [abstract]. In: Proceedings of the AACR Conference on Pancreatic Cancer: New Frontiers in Biology and Therapeutic Development; 2026 Sep 25-28; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(18_Suppl_2):Abstract nr B078.