Abstract 2677: Sequential same slide multiplex immunofluorescence and H&E staining for combined phenotypic and morphologic characterization of formalin-fixed paraffin-embedded tissue sections

Abstract

Abstract Multiplex immunofluorescence (mIF) has become an established method for characterizing the tumor immune microenvironment. Currently, hematoxylin and eosin (H&E) staining is typically performed on a serial tissue section to provide morphologic context for the mIF data. Serial sections do not represent identical cell populations, however, and are not always possible to obtain when the amount of available tissue is limited. Consequently, a method to examine the same tissue section by both fluorescence and brightfield imaging would be advantageous. Here we present a streamlined method and system for serial mIF and H&E staining on a single tissue slide for a comprehensive analysis to support high-throughput tissue immunophenotyping. The UltiMapper I/O PD-L1 kit was used for multiplex immunofluorescence staining of CD8, CD68, PD-L1, and pan-Cytokeratin in formalin-fixed, paraffin-embedded (FFPE) samples from human tonsil and primary tumor biopsies using the Leica Biosystems BOND RX autostainer. Stained tissues were imaged in five spectrally distinct fluorescence channels (DAPI, FITC, TRITC, Cy5, Cy7) on the RareCyte CyteFinder II HT Instrument. Slides were de-coverslipped and stained with H&E, then imaged with brightfield using the CyteFinder II HT instrument. To segment the tumor and stroma tissue regions, a HALO AI classifier was created. Fluorescence images were analyzed using the HALO Highplex FL module to identify CD8+ cytotoxic T-cells, CD68+ macrophages, CD68+/PD-L1+ immuno-suppressive macrophages, pan-CK+ tumor cells, and pan-CK+/PD-L1+ immune-evading tumor cells within the tumor and stromal regions identified by the H&E stain. This novel combination of fluorescence and brightfield analysis enables deep phenotyping of immune cells as well as assessment of cellular morphology and tumor architecture in the same tissue section. Citation Format: Katir K. Patel, Amanda Bares, Mael Manesse, Mark Burton, Bonnie Phillips, Kate Lillard, Anne Hellebust, Melinda Duplessis, Kyla Teplitz, Tad George. Sequential same slide multiplex immunofluorescence and H&E staining for combined phenotypic and morphologic characterization of formalin-fixed paraffin-embedded tissue sections [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2677.