Abstract 1896: Spatial proteomics and tumor-immune phenotyping identifies a diverse immune landscape in syngeneic murine tumor models

Abstract Syngeneic mouse models have a functionally intact immune system, and therefore, serve as a crucial tool for evaluation of the immune response to tumors and pre-clinical evaluation of immunotherapeutic strategies. However, the immune response varies between different syngeneic models. Identification and selection of appropriate models for pre-clinical evaluation is challenging. To understand the dynamic interplay between the tumor and immune system, we implemented multiplexed spatial proteomics across various syngeneic tumor models. Spatial mapping of multiple tumor and immune markers in untreated tumor provides an overview of the tumor immune architecture. This information can be applied to identify optimal models for preclinical immunotherapy approaches, to understand the response to therapies at the preclinical stage, and to identify potential biomarkers for clinical evaluation. The Cell DIVE Multiplexed Imaging Solution, in combination with IHC-validated antibody conjugates from Cell Signaling Technology (CST), enables profiling of immune cell populations in the context of human and mouse tumor tissue. Here, we demonstrate multiplexed Cell DIVE imaging of syngeneic mouse tumor models using a novel CST® panel of mouse-reactive antibodies. We apply segmentation and clustering analysis to identify spatially co-localized populations of cells and discuss the complexities of immune cells and their interactions. Cell type specific markers combined with multiplexed tissue imaging and spatial mapping is an approach that enables a better understanding of the anti-tumor immune response, which can be applied to address challenges associated with developing immune-based therapies. The study highlights the importance of simultaneously observing multiple immune cell types and tumor characteristics in spatial context. Citation Format: Arindam Bose, Emily Quann Alonzo, Sophie Struble, Jeremy Fisher, Richard A. Heil-Chapdelaine, Natasha F. Diaz Granados, Vasundhara Agrawal. Spatial proteomics and tumor-immune phenotyping identifies a diverse immune landscape in syngeneic murine tumor models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 1896.