Identifying immune cell phenotypes and their function by using spatial multiomics 3124

Abstract Description Advances in our understanding of the tumor microenvironment (TME) will help inform the development of next generation immunotherapies and engineered immune-cell therapies. Spatially characterizing immune cells with cell marker protein and activation marker RNA is crucial. To address this, we have developed a high throughput RNAscope™ assay on the BOND RX for same slide RNA+protein detection. We utilized the new protease-free RNAscope™ Multiomic LS assay that can detect up to 6 RNA and protein targets on the same slide with TSA-based amplification strategy that offers a strong signal boost. Here, we demonstrate the use of our pre-conjugated antibody panel and a some unconjugated primary antibodies in multiple tumor tissues. Infiltrating Cytotoxic T cell lymphocytes were detected using CD8, GZMB and IFNG co-expression. Regulatory T cells were detected using CD4, FOXP3 co-expression. PanCK was used as a tumor marker to delineate tumor from stroma. Similarly, tumor associated macrophages were detected using CD163, CD68, IL10 and IL-1B expression. We were also able to identify distinct M1 and M2 macrophage populations in the tumor samples. The RNAscope Multiomic LS assay was successfully able to interrogate different subpopulation of immune cells with high quality RNA and protein signal while maintaining tissue morphology. The high throughput capability with strong signal boosting technology makes this assay an ideal tool for identifying diagnostic and therapeutic biomarkers. Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)