Edward Stack

Multiplexed immunohistochemistry, imaging, and quantitation: A review, with an assessment of Tyramide signal amplification, multispectral imaging and multiplex analysis

Tissue sections offer the opportunity to understand a patients condition, to make better prognostic evaluations and to select optimum treatments, as evidenced by the place pathology holds today in clinical practice. Yet, there is a wealth of information locked up in a tissue section that is only partially accessed, due mainly to the limitations of tools and methods. Often tissues are assessed primarily based on visual analysis of one or two proteins, or 2-3 DNA or RNA molecules. Even while analysis is still based on visual perception, image analysis is starting to address the variability of human perception. This is in contrast to measuring characteristics that are substantially out of reach of human perception, such as parameters revealed through co-expression, spatial relationships, heterogeneity, and low abundance molecules. What is not routinely accessed is the information revealed through simultaneous detection of multiple markers, the spatial relationships among cells and tissue in disease, and the heterogeneity now understood to be critical to developing effective therapeutic strategies. Our purpose here is to review and assess methods for multiplexed, quantitative, image analysis based approaches, using new multicolor immunohistochemistry methods, automated multispectral slide imaging, and advanced trainable pattern recognition software. A key aspect of our approach is presenting imagery in a workflow that engages the pathologist to utilize the strengths of human perception and judgment, while significantly expanding the range of metrics collectable from tissue sections and also provide a level of consistency and precision needed to support the complexities of personalized medicine.

Topological analysis reveals a PD-L1 associated microenvironmental niche for Reed-Sternberg cells in Hodgkin lymphoma

Signaling between programmed cell death protein 1 (PD-1) and the PD-1 ligands (PD-L1, PD-L2) is essential for malignant Hodgkin Reed-Sternberg (HRS) cells to evade antitumor immunity in classical Hodgkin lymphoma (cHL). Copy number alterations of 9p24.1/CD274(PD-L1)/PDCD1LG2(PD-L2) contribute to robust PD-L1 and PD-L2 expression by HRS cells. PD-L1 is also expressed by nonmalignant tumor-associated macrophages (TAMs), but the relationships among PD-L1+ HRS cells, PD-L1+ TAMs, and PD-1+ T cells remain undefined. We used multiplex immunofluorescence and digital image analysis to examine the topography of PD-L1+ and PD-1+ cells in the tumor microenvironment (TME) of cHL. We find that the majority of PD-L1 in the TME is expressed by the abundant PD-L1+ TAMs, which physically colocalize with PD-L1+ HRS cells in a microenvironmental niche. PD-L1+ TAMs are enriched for contacts with T cells, and PD-L1+ HRS cells are enriched for contacts with CD4+ T cells, a subset of which are PD-1+ Our data define a unique topology of cHL in which PD-L1+ TAMs surround HRS cells and implicate CD4+ T cells as a target of PD-1 blockade.

Multiplexed tissue biomarker imaging

Multiplexed Tissue Biomarker Imaging The detection of structural and functional proteins in cells within the tumor microenvironment in tissue samples is achieved by immunolabeling with specific antibodies. These target proteins are visualized with the subsequent application of either an enzymatic

Quantitative Analysis of Immune Infiltrates in Primary Melanoma

Quantitative multiplex immunofluorescence and quantitative spatial analysis were used to evaluate the tumor microenvironment and allowed for the identification of a biomarker that correlated with survival in melanoma—the cytotoxic T lymphocyte-to-macrophage ratio. Novel methods to analyze the tumor microenvironment (TME) are urgently needed to stratify melanoma patients for adjuvant immunotherapy. Tumor-infiltrating lymphocyte (TIL) analysis, by conventional pathologic methods, is predictive but is insufficiently precise for clinical application. Quantitative multiplex immunofluorescence (qmIF) allows for evaluation of the TME using multiparameter phenotyping, tissue segmentation, and quantitative spatial analysis (qSA). Given that CD3+CD8+ cytotoxic lymphocytes (CTLs) promote antitumor immunity, whereas CD68+ macrophages impair immunity, we hypothesized that quantification and spatial analysis of macrophages and CTLs would correlate with clinical outcome. We applied qmIF to 104 primary stage II to III melanoma tumors and found that CTLs were closer in proximity to activated (CD68+HLA-DR+) macrophages than nonactivated (CD68+HLA-DR−) macrophages (P < 0.0001). CTLs were further in proximity from proliferating SOX10+ melanoma cells than nonproliferating ones (P < 0.0001). In 64 patients with known cause of death, we found that high CTL and low macrophage density in the stroma (P = 0.0038 and P = 0.0006, respectively) correlated with disease-specific survival (DSS), but the correlation was less significant for CTL and macrophage density in the tumor (P = 0.0147 and P = 0.0426, respectively). DSS correlation was strongest for stromal HLA-DR+ CTLs (P = 0.0005). CTL distance to HLA-DR− macrophages associated with poor DSS (P = 0.0016), whereas distance to Ki67− tumor cells associated inversely with DSS (P = 0.0006). A low CTL/macrophage ratio in the stroma conferred a hazard ratio (HR) of 3.719 for death from melanoma and correlated with shortened overall survival (OS) in the complete 104 patient cohort by Cox analysis (P = 0.009) and merits further development as a biomarker for clinical application. Cancer Immunol Res; 6(4); 481–93. ©2018 AACR.

Abstract A133: Imaging in cancer immunology: Phenotyping of multiple immune cell subsets in-situ in FFPE tissue sections

There has been a rapid grown in the field of tumor immunobiology in recent years as a result of recent successes in cancer immunotherapies, and it is clear that immune cells play many sometimes conflicting roles in the tumor microenvironment. However, obtaining phenotypic information about the various immune cells in and around the tumor has been a challenge. Existing methods can deliver phenotypic information on homogenous samples (e.g., flow cytometry or PCR) or morphologic information in single stain IHC. We present here a methodology for delivering quantitative per-cell marker expression and phenotyping, analogous to that obtained from flow cytometry, but from cells imaged in situ in FFPE tissue sections. This methodology combines: the sequential multi-marker labeling of up to 6 antigens using antibodies all of the same species (with a goal of reaching 8 markers); automated multispectral imaging to remove problematic FFPE tissue autofluorescence and correct cross-talk between fluorescent channels; and an automated image analysis that can quantitate the per-cell marker expression, determine the cellular phenotype, count these cells separately in the tumor compartment and in the stroma, provide high-resolution images of their distributions and provide x,y coordinate data from which spatial distance calculations can be made. We will show a 6-plex assay in breast cancer showing the application of the multiplexed staining, per-cell quantitation and cellular phenotyping in FFPE tissue sections, as well as methods to explore the spatial distributions of the phenotyped cells in and around the tumor. Citation Format: James R. Mansfield, Clifford C. Hoyt, Edward Stack, Michael Feldman, Carlo Bifulco, Bernard Fox. Imaging in cancer immunology: Phenotyping of multiple immune cell subsets in-situ in FFPE tissue sections. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A133.

Abstract A08: Imaging in cancer immunology: Phenotyping of multiple immune cell subsets in-situ in FFPE tissue sections

There has been a rapid grown in the field of tumor immunobiology in recent years as a result of recent successes in cancer immunotherapies, and it is becoming clear that immune cells play many sometimes conflicting roles in the tumor microenvironment. However, obtaining phenotypic information about the various immune cells that play these roles in and around the tumor has been a challenge. Existing methods can either deliver phenotypic information on homogenous samples (e.g., flow cytometry or PCR) or morphologic information on single immunomarkers (standard IHC). We present here a methodology for delivering quantitative per-cell marker expression and phenotyping, analogous to that obtained from flow cytometry, but from cells imaged in situ in FFPE tissue sections. This methodology combines: the sequential multi-marker labeling of up to 6 antigens using antibodies all of the same species in a single section; automated multispectral imaging (MSI) to remove the typically problematic FFPE tissue autofluorescence and correct cross-talk between fluorescent channels; and an automated image analysis that can quantitate the per-cell marker expression, determine the cellular phenotype, count these cells separately in the tumor compartment and in the stroma and provide high-resolution images of their distributions. We present here several examples of this new methodology in breast, lung and head and neck cancers. Each application example will show 6-plex multiplexed staining, per-cell quantitation of each marker and multi-marker cellular phenotyping from multispectral images of standard clinical biopsy sections, as well as methods to explore the spatial distributions of the phenotyped cells in and around the tumor. Citation Format: James R. Mansfield, Clifford C. Hoyt, Edward Stack, Steven H. Lin, Michael Feldman, Carlo Bifulco, Bernard A. Fox. Imaging in cancer immunology: Phenotyping of multiple immune cell subsets in-situ in FFPE tissue sections. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr A08.

Abstract 2238: Understanding immune phenotypes and their spatial relationships to breast adenocarcinoma in FFPE tissues

The relationship between elements of the immune system and breast tumors in situ requires an approach that leverages multiplexed immunohistochemistry (mIHC) with multispectral imaging to facilitate precise image analyses. To achieve this, we developed a novel 7-color mIHC assay, based on tyramide signal amplification, that allowed us to reliably interrogate CD3, CD4, CD8, FoxP3, CD68, and cytokeratin, in formalin-fixed, paraffin-embedded (FFPE) samples of human breast cancer. Imaging was performed using the multispectral Mantra system and inForm image analysis software. Using this specific mIHC panel and the cell segmenting and phenotyping tools in inForm, we were able to reliably identify cytotoxic T cells (CD3+ CD8+), helper T cells (CD3+ CD4+), regulatory T cells (CD3+ CD4+ FoxP3+), tumor associated macrophages (CD68+) and breast tumor cells (CK+). With cell phenotypes within the tumor microenvironment determined based on specific colocalized staining combinations, we then employed spatial point pattern analyses to examine spatial relationships between specific phenotypes. With this analysis, we were able to describe distances between cytotoxic T cells and regulatory T cells, cytotoxic T cells and tumor associated macrophages, as well as cytotoxic T cells and breast tumor cells. With this combined mIHC, multispectral imaging and advanced image analysis, we demonstrate a novel method that allows for unique tumor microenvironment assessments within in breast cancer. Through the preservation of tumor architecture available in archival FFPE tissues, these methods can advance our understanding of unique tumor microenvironment interactions, and could provide the ability to stratify responses to immunotherapies. Citation Format: Yi Zheng, Pallavi Thuse, Linying Liu, Edward C. Stack, Michael Campisano, Kent Johnson, Darryn Unfricht, Nara Narayanan, Clifford Hoyt, Milind Rajopadhye. Understanding immune phenotypes and their spatial relationships to breast adenocarcinoma in FFPE tissues. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2238.