Abstract 288: An ex-vivo 3D tumoroid model of fresh patient tissue (3D-EXplore) to assess transcriptional and compositional changes of the immune landscape in intact tumor microenvironment using single-cell proteogenomics

Abstract Background: Molecular changes underlying immune cell signaling in response to new therapy development are crucial to validate the clinical efficacy of immunotherapeutics. There are several preclinical tools including patient derived cell lines, organoid and xenograft (PDX) models to assess the efficacy of drugs. However, it is important to recapitulate the complexity of human malignancy and immune contexture within the tumor microenvironment. Here we report, an ex vivo platform (3D-EXplore) using fresh patient tumor samples with intact stromal and immune cell components to assess treatment-mediated changes in molecular and transcriptional profiles of tumor resident immune cells using a Cellular Indexing of Transcriptomes and Epitopes by sequencing (CITE-seq) platform. Methods: All tumor samples were obtained with patient consent and relevant IRB approval. Unpropagated 3D tumoroids measuring 150 µm in size with intact tumor immune microenvironment were prepared from fresh tumor samples of colon and lung tissues using proprietary technology developed at Nilogen Oncosystems. No enzymatic digestion, propagation or reassembly was used during the preparation of the tumoroids. Hundreds of tumoroids originated from different parts of each patient’s tumor sample were pooled to represent the tumor heterogeneity and treated ex vivo with or without immunostimulatory agents for 48h. Here, we applied multi-modal CITE-seq profiling using the 10X Genomics platform to interrogate cellular responses to ex vivo treatment. Culture supernatants were collected for multiplex analysis of cytokine release in media. Additionally, flow cytometry was used to assess the activation profile of resident immune cells. Results: Following sequencing of FACS sorted viable CD45 populations, the FAST-Q output files were uploaded into Cell Ranger for analysis with Loupe Browser. Multimodal analysis of transcriptomes or proteomics at the single-cell level revealed significant changes in the top 100 gene expression levels specific to CD4 and CD8+ T cells, NK cells and B cells signaling and activation upon stimulation with immunostimulatory agents. In addition, several pro and anti-inflammatory chemokines and cytokines were upregulated in response to ex vivo treatment in both colon and lung tumoroids, which coincided with marked changes in the activation status of tumor resident immune cells, as detected by multiparameter flow cytometry analysis. Conclusions: These results demonstrate Nilogen’s 3D fresh tumoroid model reflects the significant impact on activation and proliferation of tumor resident immune cells within the intact tumor microenvironment at the transcriptional level. We believe this model system can serve as a clinically relevant tool for accelerating immuno-oncology drug development. Citation Format: Jonathan P. Waterman-Smith, Jared Ehrhart, Brittany Bunch, Krithika Kodumudi, Matt Weitzman, Olivia MacIntosh, Kelly Sussman, Soner Altiok. An ex-vivo 3D tumoroid model of fresh patient tissue (3D-EXplore) to assess transcriptional and compositional changes of the immune landscape in intact tumor microenvironment using single-cell proteogenomics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 288.