1179. Deep spatial immuno-profiling through high biomarker colocalization in FFPE tumor tissue samples Abdul Mohammed, Chineme Onwubueke, and Maël Manesse Ultivue, Inc. 763D Concord Avenue, Cambridge, MA 02138 • +1-617-945-2662 • www.ultivue.com • [email protected] • Twitter: @Ultivue The recent emergence of multiplexed immunohistochemistry (IHC) has the potential to revolutionize immuno-oncology and pathology research as it enables the identification of complex cell subtypes and their interactions in the tumor environment. Comprehensive classification of the different cell types in immuno-oncology presents a unique challenge as many of the relevant biomarkers are common to large subsets of cell types within a particular cell class. Therefore, a key feature for accurate phenotypic classification is the ability to detect a high number of colocalized biomarkers. In this study, we demonstrate how the InSituPlex ® technology enables researchers to reliably label and detect phenotypes with markers expressed in the same compartment (membrane, cytoplasmic, or nuclear) on single cells of a NSCLC tissue section stained with 16 different markers. For more information, refer to poster #1183. Conclusions Introduction PD-L1 Panel APC Panel High co-expression and deep phenotyping in a single NSCLC tissue section For Research Use Only. Not for use in diagnostic procedures. Tissue samples were procured from commercial vendors for this research study. Ultivue®, InSituPlex®, UltiMapper™ are either registered trademarks or trademarks of Ultivue in the United States and/or other countries. All other trademarks are property of their respective owners. In this poster, we demonstrate research of the identification of phenotypes based on the co-expression and colocalization of biomarkers on the same cells in a lung tumor section. Analysis of the high dimensional, spatially resolved data obtained from a 16- plex assay provided phenotypic information of different lymphocytes, macrophages, dendritic cells, antigen-presenting cells, and tumor cell populations with multiple colocalized biomarkers. Overlay CD3 CD8 Cytotoxic T cells Overlay CD3 CD4 Helper T cells Overlay CD3 CD4 FOXP3 Naïve regulatory T cells Overlay CD3 CD8 GrB Cytotoxic T cells expressing Granzyme B Overlay CD3 CD4 CD45RO Memory helper T cells Overlay CD11c Dendritic cells B cells Overlay CD20 Overlay CD3 CD4 CD45RO FOXP3 Memory regulatory T cells Overlay CD3 CD8 CD45RO LAG3 PD-1 Exhausted memory cytotoxic T cells Overlay CD3 CD8 CD45RO Memory cytotoxic T cells Overlay CD68 CD163 M2 macrophages CD8 regulatory T cells Overlay CD3 CD8 FOXP3 Overlay CD68 CD163 PD-L1 Immunosuppressive M2 macrophages Overlay CD68 MHCII Antigen-presenting M1 macrophages APC Panel (ROI) CK Ki67 Overlay Proliferating tumor cells Proliferating immune evading tumor cells CK PD-L1 Ki67 Overlay DAPI CD3 CD4 CD8 CD11c CD20 CD45RO CD68 CD163 FoxP3 GranzymeB Ki67 LAG3 MHCII PD-1 PD-L1 Cytokeratin Proliferating exhausted memory T cells CD3 CD45RO PD-1 Ki67 Overlay Overlay CD3 CD8 GrB NK cells expressing Granzyme B Tumor Cells Immune Cells