PathoGraph: An Attention-Based Graph Neural Network Capable of Prognostication Based on CD276 Labelling of Malignant Glioma Cells

Computerized methods have been developed that allow quantitative morphological analyses of whole slide images (WSIs), e.g., of immunohistochemical stains. The latter are attractive because they can provide high-resolution data on the distribution of proteins in tissue. However, many immunohistochemical results are complex because the protein of interest occurs in multiple locations (in different cells and also extracellularly). We have recently established an artificial intelligence framework, PathoFusion which utilises a bifocal convolutional neural network (BCNN) model for detecting and counting arbitrarily definable morphological structures. We have now complemented this model by adding an attention-based graph neural network (abGCN) for the advanced analysis and automated interpretation of such data. Classical convolutional neural network (CNN) models suffer from limitations when handling global information. In contrast, our abGCN is capable of creating a graph representation of cellular detail from entire WSIs. This abGCN method combines attention learning with visualisation techniques that pinpoint the location of informative cells and highlight cell-cell interactions. We have analysed cellular labelling for CD276, a protein of great interest in cancer immunology and a potential marker of malignant glioma cells/putative glioma stem cells (GSCs). We are especially interested in the relationship between CD276 expression and prognosis. The graphs permit predicting individual patient survival on the basis of GSC community features. Our experiments lay a foundation for the use of the BCNN-abGCN tool chain in automated diagnostic prognostication using immunohistochemically labelled histological slides, but the method is essentially generic and potentially a widely usable tool in medical research and AI based healthcare applications.

Abstract 677: Increasing plexity of imaging mass cytometry for tumor tissue analysis

Imaging Mass Cytometry™ (IMC™) is the leading platform for high-plex tissue imaging. IMC allows for detailed assessment of cell phenotype and function using 40-plus markers simultaneously at subcellular resolution on a single slide. A comprehensive IMC panel containing structural, functional, and immune markers enables us to reveal the complex heterogeneity of tumor tissues as well as the tumor microenvironment (TME). Driven by an increase in the number of antibody markers and the addition of mRNA markers, there is an increasing demand for larger panels. In addition, increasing the number of investigated target markers on a single tissue enriches spatial characterization that may facilitate a more accurate prediction of disease progression and preclinical outcome measures in clinical research projects using tumor biopsies or tissue microarrays (TMAs). Therefore, to increase the plexity of IMC panels, it is essential to expand the number of available metal channels. Here, we demonstrate the incorporation of conjugated antibodies with yttrium (89Y) and indium (115In), two low-mass metals, for IMC application. These metal tags have been previously tested as putative channels for IMC application.

We performed IMC analysis of various tissue types stained with panels of conjugated antibodies including the novel 89Y- and 115In-conjugated antibodies. At least 3 different regions of interest (ROIs) were assessed for each of the investigated tissue types. We compared images for the 89Y- and 115In-conjugated antibodies with the images generated using Maxpar® catalog antibodies of the same clones, with a focus on marker specificity and background signal. Compared with the lanthanide-conjugated catalog antibodies, the 89Y- and 115In-conjugated antibodies showed equivalent specificity and staining quality.

Our results open a new avenue to assign markers to 89Y and 115In, which enables a larger list of potential targets to be investigated in any IMC study. Expanding the number of markers to 40-plus in Imaging Mass Cytometry will improve the imaging results necessary to identify novel cell signatures (phenotype and interactions) in the TME.

Citation Format: Thomas D. Pfister, Shaida Ouladan, Huihui Yao, Daniel Majonis, Christina Loh, Nick Zabinyakov. Increasing plexity of imaging mass cytometry for tumor tissue analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 677.

Abstract 5142: 50-parameter flow cytometry by CyTOF empowers comprehensive single-cell immune profiling of pulmonary immunosenescence in aged mice

High-parameter flow cytometry is essential for human and mouse studies to discover novel immunological mechanisms of cancer, infections, and immunosenescence. It plays an increasingly important role in cancer research to ensure clinical therapeutic success but is limited by the large amount of cell samples needed for staining controls. CyTOF® technology has transformed flow cytometry by enabling 50-plus-marker analysis per tube of sample, with easy panel design and no need for single-stained or autofluorescence controls. Flow cytometry by CyTOF provides an efficient and unbiased approach to discovering novel subsets and unique functional states of immune cells, maximizing insights from precious samples.

Immunosenescence perturbs lung cancer onset and development, yet the mechanisms remain largely unknown. To study the pulmonary immune populations in aged (75 weeks old) and young adult (6-8 weeks old) mice, we built a 50-parameter panel (2 for single live-cell identification, 6 for live-cell sample barcoding, and 42 for immune profiling). A core panel of 32 antibodies was selected from Standard BioTools™ catalogs to detect key cell lineage and functional surface markers. A complementary panel with 10 Maxpar® antibodies was added to further study functional cell states. Maxpar Pathsetter™ software was used to create an automated analytical model for high-dimensional analysis.

The 50-parameter panel successfully identified over 30 lymphoid and myeloid cell subsets including but not limited to T cells, B cells, NK cells, alveolar macrophages (AMs), dendritic cells, and neutrophils. The panel enabled high-fidelity detection of over 15 functional markers mediating proliferation, activation, inhibition, migration, tissue residence, and cellular metabolism. Automated in-depth analysis by Maxpar Pathsetter efficiently identified many aging-associated alterations in cell frequencies and functional states such as the enrichment of PD-1+ T cells and CD27- γδ T cells that could potentially perturb anti-tumor immunity. Moreover, CyTOF technology is uniquely advanced in characterizing autofluorescent cells such as AMs. A pro-inflammatory state (higher expression of MHC-II, CD80, and PD-L1) was specifically defined for AMs in aged lungs.

This study demonstrates comprehensive single-cell immune profiling of mouse tissues with the products and solutions provided by Standard BioTools. Both the 50-parameter panel and Maxpar Pathsetter analytical model can be customized for deep characterization of specific immune populations according to the requirements of various cancer studies in mice. By utilizing end-to-end solutions offered by Standard BioTools, flow cytometry by CyTOF can significantly facilitate the mechanistic studies of mouse models to expand the understanding of human cancers and accelerate therapeutic development.

Citation Format: Wenxi Xu, Stephen Li, Alexandre Bouzekri, Lauren Tracey, Christina Loh. 50-parameter flow cytometry by CyTOF empowers comprehensive single-cell immune profiling of pulmonary immunosenescence in aged mice. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5142.

Abstract 676: Neuro-oncology imaging mass cytometry panels enable spatial investigation of brain tumor microenvironment

Brain neoplasms represent a complex form of cancer that is one of the most challenging to classify and treat. Over 120 different tumor subtypes originate from various parts of the central nervous system, which makes identifying the composition of the tumor microenvironment (TME) vital for early assessment of progression, treatment, and prevention. We developed high-plex proteomic analysis tools to thoroughly characterize the TME of both human and mouse brain tissues using Imaging Mass Cytometry™ (IMC™). IMC offers unprecedented insight into the TME by uncovering the spatial distribution of 40-plus distinct molecular markers without autofluorescence, facilitating the research of brain neoplasms. Here, we demonstrate the application of high-plex human and mouse neuro-oncology IMC panels on normal and tumor formalin-fixed paraffin-embedded brain tissues.

A basic neurophenotyping panel was developed and used to customize the Maxpar® Human and Maxpar OnDemand™ Mouse Immuno-Oncology IMC Panel Kits. Human and mouse neuro-oncology panels provide deep phenotyping and characterization of brain TME composition. These neuro panels consist of cross-reactive clones and enable flexible panel design for brain-specific research goals, such as brain tumor classification, and assessment of neuronal inflammation, degeneration, and development.

We applied the neuro-oncology panels on tissue microarrays (TMAs) containing a variety of human brain tumors and mouse glioblastoma and neuroblastoma tissues. Normal brain tissues were used for comparative analysis as controls. The Hyperion™ Imaging System was utilized to digitize images from the tissues followed by quantitative analysis to assess the cellular composition of normal and cancerous brain TME.

We successfully identified major cell populations that make up human and mouse brain matter, such as neurons, astrocytes, microglia, and oligodendrocytes. Various tumor cell phenotypes, resident and infiltrating cells, and resting and activated microglia were detected in multiple tumor subtypes. Subsequent single-cell analysis provided a comprehensive and quantitative assessment of the brain TME in our samples. We classified the distinct states of neurons and quantified myeloid and lymphoid immune cell infiltration across normal, astrocytoma, and glioblastoma tissues.

Empowered by high-plex neuro-oncology panels, IMC can accelerate brain tumor research and provide insights into the spatial complexity of neuronal neoplasms.

Citation Format: Nick Zabinyakov, Qanber Raza, Christina Loh. Neuro-oncology imaging mass cytometry panels enable spatial investigation of brain tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 676.

Abstract 2250: Immuno-oncology study to profile the tumor microenvironment in multiple human cancers using high-plex imaging mass cytometry

Immune profiling of tumor tissues has become a key tool in understanding the complexity of the tumor microenvironment (TME), for predictive biomarker discovery, and in cancer treatment. The presence of tumor-infiltrating lymphocytes has been associated with benefit from therapy. Furthermore, the TME also contains immunosuppressive elements that can impede immune response. Imaging Mass Cytometry™ (IMC™) enables detailed assessment of cell phenotype and function using 40-plus markers simultaneously at subcellular resolution on a single slide without spectral overlap or background autofluorescence. High-plex IMC has enabled us to evaluate the TME in different cancer histologies including in highly autofluorescent tissue types like lung, hepatocellular carcinoma, and skin melanoma.

The Maxpar® Human Immuno-Oncology IMC Panel Kit (201508) was customized using antibodies from the Standard BioTools™ catalog to create panels for tissue-based immuno-oncology research. Data acquisition was performed using a Hyperion™ Imaging System. To facilitate cell segmentation, an IMC Cell Segmentation Kit (TIS-00001) was applied to enhance cell membrane boundaries. We applied a pixel classification approach and CellProfiler™ for single-cell segmentation. We used histoCAT™ for single-cell analysis to visualize protein expression in various cancer types via PhenoGraph clustering and t-SNE maps.

Our panels were applied to normal and cancer human tissue microarrays (TMAs) to phenotype and analyze cell populations in these tissues. We provide detailed analysis of the TME by classifying activation state of immune cell populations, epithelial-to-mesenchymal transition (EMT) progression, and composition of the extracellular matrix. In-depth single-cell analysis quantitatively evaluated the cellular makeup and immune cell component in the TME of cancer tissues and identified major tumor, immune, and stromal cell phenotypes. This work demonstrates the capability of IMC for quantitative and spatial identification of multiple immune parameters in the TME on a single slide of cancer patient samples (e.g. tumor microarray).

For Research Use Only. Not for use in diagnostic procedures.

Citation Format: Thomas D. Pfister, Liang Lim, Shaida Ouladan, Nick Zabinyakov, Qanber Raza, Christina Loh. Immuno-oncology study to profile the tumor microenvironment in multiple human cancers using high-plex imaging mass cytometry [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2250.

An Open-Source AI Framework for the Analysis of Single Cells in Whole-Slide Images with a Note on CD276 in Glioblastoma

Routine examination of entire histological slides at cellular resolution poses a significant if not insurmountable challenge to human observers. However, high-resolution data such as the cellular distribution of proteins in tissues, e.g., those obtained following immunochemical staining, are highly desirable. Our present study extends the applicability of the PathoFusion framework to the cellular level. We illustrate our approach using the detection of CD276 immunoreactive cells in glioblastoma as an example. Following automatic identification by means of PathoFusion's bifocal convolutional neural network (BCNN) model, individual cells are automatically profiled and counted. Only discriminable cells selected through data filtering and thresholding were segmented for cell-level analysis. Subsequently, we converted the detection signals into the corresponding heatmaps visualizing the distribution of the detected cells in entire whole-slide images of adjacent H&E-stained sections using the Discrete Wavelet Transform (DWT). Our results demonstrate that PathoFusion is capable of autonomously detecting and counting individual immunochemically labelled cells with a high prediction performance of 0.992 AUC and 97.7% accuracy. The data can be used for whole-slide cross-modality analyses, e.g., relationships between immunochemical signals and anaplastic histological features. PathoFusion has the potential to be applied to additional problems that seek to correlate heterogeneous data streams and to serve as a clinically applicable, weakly supervised system for histological image analyses in (neuro)pathology.

Abstract 3908: A streamlined and automated approach to high-content cytometric immunophenotyping with CyTOF XT

High-parameter immune profiling is crucial in translational and clinical research to quantify changes in immune cell populations over time. CyTOF® mass cytometry is a high-plex, single-cell analysis platform that uses isotopically pure metal-labeled antibodies. The major advantage of CyTOF is its ability to resolve 40-plus markers in a single panel without compensation, making mass cytometry ideal for routine immunophenotyping. The autosampler module of CyTOF XT™ provides significant time savings by allowing automated sample acquisition. Tubes of pelleted stained samples are loaded into the Autosampler carousel, and the samples are resuspended with EQ™ Calibration Beads for acquisition. User input is only required during instrument startup, tuning, and batch setup. The added automation of CyTOF XT provides a streamlined workflow for suspension mass cytometry. Testing was performed to ensure that the data obtained on CyTOF XT was comparable to manual acquisition systems. The performance of CyTOF XT was tested in parallel with its predecessor, Helios™. Several workflows and applications for suspension mass cytometry including sample barcoding with the Cell-ID™ 20-Plex Pd Barcoding Kit, and surface, cytoplasmic, and nuclear staining and phosphostaining were evaluated on human PBMC. Manual gating analysis was performed to assess population frequencies and median intensities for each marker. Resolution index was calculated to assess how well positive and negative populations separated from each other. There was no significant difference between population frequencies analyzed between the two CyTOF systems. Moreover, samples acquired on CyTOF XT, on average, resulted in greater signal resolution between positive and negative populations compared to Helios. The Maxpar Direct Immune Profiling System was also compared on CyTOF XT and Helios using human whole blood and PBMC. The Maxpar® Direct™ Immune Profiling Assay™ and Maxpar Pathsetter™ software were developed as a sample-to-answer system for human immune profiling using CyTOF. The Maxpar Direct Immune Profiling Assay includes an optimized panel of 30 unique markers in a dry, single-tube format. Maxpar Pathsetter is an automated software used to report population statistics, stain assessments, and relevant data plots for the panel. The automated staining assessment in Maxpar Pathsetter was compared between files acquired on CyTOF XT and Helios. Comparable population frequencies were obtained between the two acquisition systems, and improved staining assessment was observed on CyTOF XT. Overall, these studies demonstrate that CyTOF XT generates better signal resolution as compared to Helios. The automated acquisition of CyTOF XT enables researchers to streamline immunophenotyping of human samples while accurately and reproducibly monitoring changes in immune cell subsets.

For Research Use Only. Not for use in diagnostic procedures.

Citation Format: Thiru Selvanantham, Stephen K.H. Li, Nick Zabinyakov, Alexandre Bouzekri, Raymond Jong, Michael Sullivan, Alexander Laboda, Daniel Majonis, Christina Loh. A streamlined and automated approach to high-content cytometric immunophenotyping with CyTOF XT [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 3908.

Abstract 2035: Imaging mass cytometry identifies structural and cellular composition of the mouse tissue microenvironment

Imaging Mass Cytometry™ (IMC™) is a vital tool to deeply characterize the complexity and diversity of any tissue without disrupting spatial context. The Hyperion™ Imaging System utilizes IMC, based on CyTOF® technology, to simultaneously assess up to 40 individual structural and functional markers in tissues, providing unprecedented insight into the organization and function of tissue microenvironment. We have previously demonstrated the application of IMC in combination with Maxpar® panel kits to highlight cellular composition of human tissues. Here, we showcase the recently released Maxpar OnDemand Antibodies for IMC application on mouse tissue. We introduced 11 additional biomarkers to our existing mouse antibody catalog, providing the basis for the use of high-multiplex imaging in preclinical investigations. To demonstrate the IMC workflow on mouse tissue, we analyzed a normal mouse tissue microarray using IMC spatial proteomic analysis. Tissues were stained with a 20-marker panel designed to highlight tissue architecture and major immune lineage markers combined with our IMC Cell Segmentation Kit*. The IMC Cell Segmentation Kit facilitates identification of cellular borders using plasma membrane markers that lead to improved nucleus and plasma membrane demarcation. We generated a detailed spatial map of the heterogeneous tissue architecture and successfully identified immune, epithelial, and stromal cell populations in various mouse tissues. Additionally, we classified the activation state of immune cell populations, adhesion state of epithelial cells, and molecular composition of the extracellular matrix.Overall, this work demonstrates the capability of IMC to identify subcellular localization of cellular and structural markers in the mouse tissue microenvironment. Information gained from IMC studies will enable in-depth high-throughput phenotypic characterization of the tissue microenvironment in various mouse models of development and disease, and thus accelerate preclinical discoveries.

*The IMC Cell Segmentation Kit is part of the Innovative Solutions menu of custom-made reagents and workflows developed and tested by Fluidigm scientists to give faster access to new cutting-edge solutions for high-multiplex single-cell analysis. Innovative Solutions are not part of the Maxpar catalog.

For Research Use Only. Not for use in diagnostic procedures.

Citation Format: Qanber Raza, Michael Cohen, Smriti Kala, Liang Lim, Geneve Awong, Andrew Quong, Christina Loh. Imaging mass cytometry identifies structural and cellular composition of the mouse tissue microenvironment [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 2035.

An automated approach to high-plex cytometric immunophenotyping with CyTOF XT

CyTOF® mass cytometry is a single-cell analysis platform that uses isotope-tagged antibodies to resolve 50-plus markers in a single tube without signal compensation, making CyTOF ideal for routine immunophenotyping. CyTOF XT™, the latest CyTOF system, features automated sample acquisition. Stained samples were acquired in parallel using the automated CyTOF XT system and manually, using the Helios™ system, to assess performance of the automated system.

Multiple suspension mass cytometry staining workflows were evaluated. Population frequencies and resolution indices for markers were assessed by manual gating. There was no significant difference between population frequencies analyzed between the two CyTOF systems. On average, samples acquired on CyTOF XT resulted in greater resolution between positive and negative populations compared to Helios.

The Maxpar® Direct™ Immune Profiling System, which comprises the Maxpar® Direct™ Immune Profiling Assay™ and Maxpar Pathsetter™ software, was also compared on the CyTOF XT and Helios systems. The Maxpar Direct Immune Profiling Assay includes a 30-marker panel in a dry, single-tube format for staining human whole blood or PBMC. Maxpar Pathsetter automates reporting of population statistics and stain assessments for the panel. Maxpar Pathsetter showed comparable population frequencies between the two CyTOF systems and improved staining assessment on CyTOF XT.

Overall, these studies find that the CyTOF XT system generates better signal resolution than the Helios system. Automated acquisition by CyTOF XT enables researchers to accurately and reproducibly streamline human immunophenotyping.

For Research Use Only. Not for use in diagnostic procedures.

Imaging Mass Cytometry identifies structural and cellular composition of the mouse tissue microenvironment

Imaging Mass Cytometry™ (IMC™) is a vital tool to deeply characterize the complexity and diversity of any tissue without disrupting spatial context. The Hyperion™ Imaging System utilizes IMC, based on CyTOF® technology, to assess up to 40 individual structural and functional markers in tissues, providing unprecedented insight into the organization and function of tissue microenvironment. We have previously demonstrated the application of IMC in combination with Maxpar® panel kits on human tissues. Here, we showcase Maxpar OnDemand Antibodies for IMC application including 11 new highly relevant markers to construe cellular and molecular composition of mouse tissues.

We analyzed a normal mouse tissue microarray using IMC spatial proteomic analysis. Tissues were stained with a 20-marker panel designed to highlight tissue architecture and major immune lineage markers. We generated a detailed spatial map of the diverse tissue architecture and successfully identified immune, epithelial, and stromal cell populations in various mouse tissues. Additionally, we classified the activation state of immune cell populations, adhesion state of epithelial cells, and molecular composition of the extracellular matrix.

This work demonstrates the capability of IMC to identify subcellular localization of cellular and structural markers in the mouse tissue microenvironment. Future studies utilizing IMC in combination with Maxpar OnDemand Antibodies will enable in-depth phenotypic characterization of the tissue microenvironment in various mouse models of development and disease, and thus provide the basis for the use of high-multiplex imaging in preclinical investigations.

For Research Use Only. Not for use in diagnostic procedures.

Extending the capabilities of a high-parameter immunophenotyping assay with cytoplasmic staining applications for mass cytometry

Maxpar® Direct™ Immune Profiling Assay™ (Cat. No. 201325) is a 30-marker panel for suspension mass cytometry. This panel provides an unprecedented sample-to-answer solution for detecting and analyzing 30 surface markers in a single experiment. The 18 open mass channels in the Maxpar Direct Assay facilitate panel expansion and enable flexibility for higher multiplexity and applications. Among the potential complementary applications, intracellular cytokine staining (ICS) is of particular interest as it may be used to assess infiltrating immune cell phenotypes in the tumor microenvironment. However, for the purpose of assessing cell viability in this workflow, the effectiveness of the Cell-ID™ Intercalator-Rh (103Rh, Cat. No. 201103) included in the Maxpar Direct Assay is in question, as cell permeabilization during ICS can potentially damage the DNA-intercalator bond. In this study, we investigated the compatibility of 103Rh with intracellular staining. We stained either human peripheral blood mononuclear cell or whole blood samples with the Maxpar Direct Assay followed by intracellular staining for the detection of expressed cytokines. We demonstrate that 103Rh provides equivalent functionality as a cell viability indicator during intracellular staining for cytoplasmic proteins compared to the benchmark Cell-ID Cisplatin-194Pt (Cat. No. 201194). This work was designed to support use of the Maxpar Direct Immune Profiling Assay in combination with additional intracellular markers. Overall, these findings expand the applicability of Cell-ID Intercalator-Rh (103Rh) to processes that involve cytoplasmic staining.

For Research Use Only. Not for use in diagnostic procedures.

Feasibility of modified-TEP technique for large inguinoscrotal and large femoral hernia and its advantages

PURPOSE

To describe the feasibility of modified-TEP technique in reducing dead space in large inguinoscrotal and large femoral hernia to prevent seroma, reduce recurrence and complications.

METHODS

This is a case series of patients who have completed a minimum of 9 months follow-up after undergoing elective endo-laparoscopic inguinal hernia repair with modified-TEP technique for large inguinoscrotal and large femoral hernia in a single institution from June to October 2020.

RESULTS

14 large inguinoscrotal hernia and 4 large femoral hernia were repaired using the modified-TEP technique in 15 patients. These patients reported minimal pain after surgery. There were no reported seroma, complications or recurrences up to 9 months follow-up period.

CONCLUSION

Modified-TEP technique for large inguinoscrotal and large femoral hernia has shown good outcomes and patients reported minimum levels of pain. In experienced hands, it is safe, feasible and effective in reducing seroma formation and hernia recurrence.

Abstract 1676: A comprehensive whole blood CyTOF immune monitoring panel with expanded surface and intracellular markers using the Maxpar Direct Immune Profiling Assay

In-depth monitoring of the immune response to cancer and infection is vital to ascertain disease status and to assess immunotherapeutic options. Time-of-flight technology, the basis of CyTOF® mass cytometry, enables multiplex proteomic cellular phenotyping with 50 or more markers, making it ideal for comprehensive immune profiling. Unlike fluorescence-dependent approaches, which require signal compensation that makes the development of larger panels more challenging, CyTOF utilizes monoisotopic metal-tagged antibodies that exhibit minimal background signal, enabling the highest-resolution multiparametric landscape of a single cell. The Maxpar® Direct™ Immune Profiling Assay™ is a pre-titrated dried-down 30-antibody cocktail preparation for immune profiling of human whole blood or PBMC. This assay is used with Maxpar Pathsetter™ software, which resolves whole blood into 37 immune populations comprising major lineage populations and their subsets, such as CD4 Th subsets and B and T cell memory cells, as well as stratifications of myeloid populations. The resulting system is a simple sample-to-answer solution for immune monitoring studies. Here, we expanded the 30-marker assay with 14 additional antibodies comprising pertinent targets of immunotherapy, including the exhaustion markers PD-1, PD-L1, Tim-3 and CTLA-4, and co-stimulation markers 4-1BB and ICOS. We also demonstrated the compatibility of the assay with downstream intracellular staining for cytoplasmic markers IFN-γ, TNF-α, IL-2, perforin and granzyme B for assessment of cellular function in 4h PMA/ionomycin-stimulated whole blood cultures. Next, we modified the existing Pathsetter model to automate the analysis of whole blood stained with the expanded panel to generate reports on key immune cell populations, percentages of exhausted cells and cell subsets producing cytokines. Last, to demonstrate the ability of this expanded panel to identify antigen-specific T cell subsets accompanied by their in-depth phenotypic assessment, we tested this panel against CMV peptide-stimulated whole blood samples. We demonstrated the flexibility of the Maxpar Direct Immune Profiling Assay in panel customization and a streamlined workflow for automated analysis to enable comprehensive immune profiling of human whole blood. For Research Use Only. Not for use in diagnostic procedures.

Citation Format: Shariq Mujib, Stephen K. Li, Nick Zabinyakov, Christina Loh. A comprehensive whole blood CyTOF immune monitoring panel with expanded surface and intracellular markers using the Maxpar Direct Immune Profiling Assay [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1676.

A single-tube, 44-marker CyTOF assay to assess antigen-specific immunity in whole blood human samples with data analysis solution

Monitoring the immune response in the setting of infectious disease and cancer is critical to assess disease status and targets of immune therapy. CyTOF® mass cytometry enables multiplex cellular phenotyping with more than 50 markers, making it ideal for comprehensive immune profiling. CyTOF technology utilizes antibodies tagged with unique monoisotopic metals, resulting in distinct signals that provide a high-resolution multiparametric landscape of a single cell. The Maxpar® Direct™ Immune Profiling Assay™ is a pre-titrated, dried-down, 30-marker antibody cocktail for immune profiling of human whole blood and PBMC by CyTOF. Paired with Maxpar Pathsetter™ software, stained samples are automatically resolved into 37 immune populations including major lineages and their subsets. In this study, we expanded the 30-marker assay to a 44-marker panel including exhaustion markers such as PD-1 and CTLA-4, co-stimulation markers 4-1BB and ICOS, and intracellular cytoplasmic markers IFN-γ, TNF-α, IL-2, perforin and granzyme B to assess cellular function in PMA/ionomycin-stimulated whole blood cultures. We modified the existing Maxpar Pathsetter model to automate the analysis of the expanded panel and report on additional functional parameters such as T cell exhaustion and cytokine production. Next, we applied this panel to whole blood stimulated with CMV peptides to investigate antigen-specific immune responses in a viral infection model in concert with in-depth phenotypic assessment. Collectively, we demonstrate the flexibility of the Maxpar Direct Immune Profiling Assay to incorporate additional surface and intracellular markers to study antigen-specific immunity in the context of whole blood immune profiling.

For RUO.

PathoFusion: An Open-Source AI Framework for Recognition of Pathomorphological Features and Mapping of Immunohistochemical Data

We have developed a platform, termed PathoFusion, which is an integrated system for marking, training, and recognition of pathological features in whole-slide tissue sections. The platform uses a bifocal convolutional neural network (BCNN) which is designed to simultaneously capture both index and contextual feature information from shorter and longer image tiles, respectively. This is analogous to how a microscopist in pathology works, identifying a cancerous morphological feature in the tissue context using first a narrow and then a wider focus, hence bifocal. Adjacent tissue sections obtained from glioblastoma cases were processed for hematoxylin and eosin (H&E) and immunohistochemical (CD276) staining. Image tiles cropped from the digitized images based on markings made by a consultant neuropathologist were used to train the BCNN. PathoFusion demonstrated its ability to recognize malignant neuropathological features autonomously and map immunohistochemical data simultaneously. Our experiments show that PathoFusion achieved areas under the curve (AUCs) of 0.985 ± 0.011 and 0.988 ± 0.001 in patch-level recognition of six typical pathomorphological features and detection of associated immunoreactivity, respectively. On this basis, the system further correlated CD276 immunoreactivity to abnormal tumor vasculature. Corresponding feature distributions and overlaps were visualized by heatmaps, permitting high-resolution qualitative as well as quantitative morphological analyses for entire histological slides. Recognition of more user-defined pathomorphological features can be added to the system and included in future tissue analyses. Integration of PathoFusion with the day-to-day service workflow of a (neuro)pathology department is a goal. The software code for PathoFusion is made publicly available.

Expanding the capabilities of the Maxpar Direct Immune Profiling Assay with additional markers, and customization of the analysis model in Maxpar Pathsetter

Mass cytometry, which utilizes CyTOF® technology, is a single-cell analysis platform that uses metal-tagged antibodies. CyTOF can resolve more than 50 parameters in a single panel without the need for compensation, making it an ideal solution for routine enumeration of immune cells. The Maxpar® Direct™ Immune Profiling System is a sample-to-answer solution for human immune profiling using mass cytometry. The Maxpar®Direct™ Immune Profiling Assay™ is an optimized 30-marker panel contained in a dry single-tube format for human whole blood or PBMC staining, and samples are acquired on the Helios™ system. Maxpar Pathsetter™ is an automated software that reports cell counts, percentage calculations, and staining intensity. It also produces graphical elements such as dot plots and a Cen-se′™ graph for 37 immune cell populations. The panel can be tailored by adding markers to open channels, the Maxpar Pathsetter model can then be customized to measure expression markers on existing classified populations or identify additional immune cell subsets.

We present data where the Maxpar Direct Immune Profiling Assay is used as a core immunophenotyping panel and additional markers are added to create a nearly 50 marker panel. Added markers are used to identify MDSCs, further classify existing cell populations, and measure immuno-oncology related markers including OX40, TIM-3, Fas, PD-1, PD-L1, ICOS, and TIGIT. We demonstrate how the Maxpar Pathsetter model is modified to incorporate the added markers.

The ability to customize the Maxpar Pathsetter model and expand the Maxpar Direct Immune Profiling Assay allows for flexibility of the system. It allows researchers to have a streamlined solution for broad immune profiling using mass cytometry.

Multiple tolerance defects contribute to the breach of B cell tolerance in New Zealand Black chromosome 1 congenic mice

Lupus is characterized by a loss of B cell tolerance leading to autoantibody production. In this study, we explored the mechanisms underlying this loss of tolerance using B6 congenic mice with an interval from New Zealand Black chromosome 1 (denoted c1(96–100)) sufficient for anti-nuclear antibody production. Transgenes for soluble hen egg white lysozyme (sHEL) and anti-HEL immunoglobulin were crossed onto this background and various tolerance mechanisms examined. We found that c1(96–100) mice produced increased levels of IgM and IgG anti-HEL antibodies compared to B6 mice and had higher proportions of germinal center B cells and long-lived plasma cells, suggesting a germinal center-dependent breach of B cell anergy. Consistent with impaired anergy induction, c1(96–100) double transgenic B cells showed enhanced survival and CD86 upregulation. Hematopoietic chimeric sHEL mice with a mixture of B6 and c1(96–100) HEL transgenic B cells recapitulated these results, suggesting the presence of a B cell autonomous defect. Surprisingly, however, there was equivalent recruitment of B6 and c1(96–100) B cells into germinal centers and differentiation to splenic plasmablasts in these mice. In contrast, there were increased proportions of c1(96–100) T follicular helper cells and long-lived plasma cells as compared to their B6 counterparts, suggesting that both B and T cell defects are required to breach germinal center tolerance in this model. This possibility was further supported by experiments showing an enhanced breach of anergy in double transgenic mice with a longer chromosome 1 interval with additional T cell defects.

mir-181a-1/b-1 Modulates Tolerance through Opposing Activities in Selection and Peripheral T Cell Function

Understanding the consequences of tuning TCR signaling on selection, peripheral T cell function, and tolerance in the context of native TCR repertoires may provide insight into the physiological control of tolerance. In this study, we show that genetic ablation of a natural tuner of TCR signaling, mir-181a-1/b-1, in double-positive thymocytes dampened TCR and Erk signaling and increased the threshold of positive selection. Whereas mir-181a-1/b-1 deletion in mice resulted in an increase in the intrinsic reactivity of naive T cells to self-antigens, it did not cause spontaneous autoimmunity. Loss of mir-181a-1/b-1 dampened the induction of experimental autoimmune encephalomyelitis and reduced basal TCR signaling in peripheral T cells and their migration from lymph nodes to pathogenic sites. Taken together, these results demonstrate that tolerance can be modulated by microRNA gene products through the control of opposing activities in T cell selection and peripheral T cell function.

Regulation of immune responses and tolerance: the microRNA perspective

Much has been learned about the molecular and cellular components critical for the control of immune responses and tolerance. It remains a challenge, however, to control the immune response and tolerance at the system level without causing significant toxicity to normal tissues. Recent studies suggest that microRNA (miRNA) genes, an abundant class of non-coding RNA genes that produce characteristic approximately 22 nucleotides small RNAs, play important roles in immune cells. In this article, we discuss emerging knowledge regarding the functions of miRNA genes in the immune system. We delve into the roles of miRNAs in regulating signaling strength and threshold, homeostasis, and the dynamics of the immune response and tolerance during normal and pathogenic immunological conditions. We also present observations based on analyzes of miR-181 family genes that indicate the potential functions of primary and/or precursor miRNAs in target recognition and explore the impact of these findings on target identification. Finally, we illustrate that despite the subtle effects of miRNAs on gene expression, miRNAs have the potential to influence the outcomes of normal and pathogenic immune responses by controlling the quantitative and dynamic aspects of immune responses. Tuning miRNA functions in immune cells, through gain- and loss-of-function approaches in mice, may reveal novel approach to restore immune equilibrium from pathogenic conditions, such as autoimmune disease and leukemia, without significant toxicity.

Identification of a lupus-susceptibility locus leading to impaired clearance of apoptotic debris on New Zealand Black chromosome 13

Systemic lupus erythematosus is a chronic multi-organ autoimmune disease marked mainly by the production of anti-nuclear antibodies. Nuclear antigens become accessible to the immune system following apoptosis and defective clearance of apoptotic debris has been shown in several knockout mouse models to promote lupus. However, genetic loci associated with defective clearance are not well defined in spontaneously arising lupus models. We previously showed that introgression of the chromosome 13 interval from lupus-prone New Zealand Black (NZB) mice onto a non-autoimmune B6 genetic background (B6.NZBc13) recapitulated many of the NZB autoimmune phenotypes. Here, we show that B6.NZBc13 mice have impaired clearance of apoptotic debris by peritoneal and tingible-body macrophages and have narrowed down the chromosomal interval of this defect using subcongenic mice with truncated NZB chromosome 13 intervals. This chromosomal region (81-94 Mb) is sufficient to produce polyclonal B- and T-cell activation, and expansion of dendritic cells. To fully recapitulate the autoimmune phenotypes seen in B6.NZBc13 mice, at least one additional locus located in the centromeric portion of the interval is required. Thus, we have identified a novel lupus susceptibility locus on NZB chromosome 13 that is associated with impaired clearance of apoptotic debris.

TLR tolerance reduces IFN-alpha production despite plasmacytoid dendritic cell expansion and anti-nuclear antibodies in NZB bicongenic mice

Genetic loci on New Zealand Black (NZB) chromosomes 1 and 13 play a significant role in the development of lupus-like autoimmune disease. We have previously shown that C57BL/6 (B6) congenic mice with homozygous NZB chromosome 1 (B6.NZBc1) or 13 (B6.NZBc13) intervals develop anti-nuclear antibodies and mild glomerulonephritis (GN), together with increased T and B cell activation. Here, we produced B6.NZBc1c13 bicongenic mice with both intervals, and demonstrate several novel phenotypes including: marked plasmacytoid and myeloid dendritic cell expansion, and elevated IgA production. Despite these changes, only minor increases in anti-nuclear antibody production were seen, and the severity of GN was reduced as compared to B6.NZBc1 mice. Although bicongenic mice had increased levels of baff and tnf-α mRNA in their spleens, the levels of IFN-α-induced gene expression were reduced. Splenocytes from bicongenic mice also demonstrated reduced secretion of IFN-α following TLR stimulation in vitro. This reduction was not due to inhibition by TNF-α and IL-10, or regulation by other cellular populations. Because pDC in bicongenic mice are chronically exposed to nuclear antigen-containing immune complexes in vivo, we examined whether repeated stimulation of mouse pDC with TLR ligands leads to impaired IFN-α production, a phenomenon termed TLR tolerance. Bone marrow pDC from both B6 and bicongenic mice demonstrated markedly inhibited secretion of IFN-α following repeated stimulation with a TLR9 ligand. Our findings suggest that the expansion of pDC and production of anti-nuclear antibodies need not be associated with increased IFN-α production and severe kidney disease, revealing additional complexity in the regulation of autoimmunity in systemic lupus erythematosus.

Epistatic suppression of fatal autoimmunity in New Zealand black bicongenic mice

Numerous mapping studies have implicated genetic intervals from lupus-prone New Zealand Black (NZB) chromosomes 1 and 4 as contributing to lupus pathogenesis. By introgressing NZB chromosomal intervals onto a non-lupus-prone B6 background, we determined that: NZB chromosome 1 congenic mice (denoted B6.NZBc1) developed fatal autoimmune-mediated kidney disease, and NZB chromosome 4 congenic mice (denoted B6.NZBc4) exhibited a marked expansion of B1a and NKT cells in the surprising absence of autoimmunity. In this study, we sought to examine whether epistatic interactions between these two loci would affect lupus autoimmunity by generating bicongenic mice that carry both NZB chromosomal intervals. Compared with B6.NZBc1 mice, bicongenic mice demonstrated significantly decreased mortality, kidney disease, Th1-biased IgG autoantibody isotypes, and differentiation of IFN-γ-producing T cells. Furthermore, a subset of bicongenic mice exhibited a paucity of CD21(+)CD1d(+) B cells and an altered NKT cell activation profile that correlated with greater disease inhibition. Thus, NZBc4 contains suppressive epistatic modifiers that appear to inhibit the development of fatal NZBc1 autoimmunity by promoting a shift away from a proinflammatory cytokine profile, which in some mice may involve NKT cells.

An intrinsic B-cell defect supports autoimmunity in New Zealand black chromosome 13 congenic mice

Introgression of a New Zealand Black (NZB) chromosome 13 interval onto a C57BL/6 (B6) background (B6.NZBc13) is sufficient to produce many hallmarks of lupus, including high-titre anti-chromatin antibody production, abnormal B- and T-cell activation, and renal disease. In this study we sought to characterize the immune defects leading to these abnormalities. By generating hematopoietic chimeras and BCR transgenic mice, we show that the congenic autoimmune phenotype can be transferred by BM cells and requires the presence of autoreactive B cells. Using the hen egg white lysozyme immunoglobulin transgenic mouse model, we demonstrate that B-cell anergy, deletion, and receptor editing are intact. Nevertheless, congenic B cells exhibit altered peripheral B-cell selection, as demonstrated by enhanced survival and activation of endogenous B cells with autoreactivity to chromatin and Sm/ribonucleoprotein. Given the autoantibody specificities to nuclear antigens, TLR signalling was assessed. B6.NZBc13 B cells were hyper-responsive to poly(I:C), a TLR3 ligand, demonstrating enhanced proliferation and survival as compared to B6 B cells. Our findings indicate the presence of an intrinsic B-cell defect on NZB chromosome 13 that results in hyper-responsiveness to a dsRNA analogue and implicates its potential supporting role in the generation of autoimmunity in B6.NZBc13 mice.

B cell activating factor (BAFF) and T cells cooperate to breach B cell tolerance in lupus-prone New Zealand Black (NZB) mice

The presence of autoantibodies in New Zealand Black (NZB) mice suggests a B cell tolerance defect however the nature of this defect is unknown. To determine whether defects in B cell anergy contribute to the autoimmune phenotype in NZB mice, soluble hen egg lysozyme (sHEL) and anti-HEL Ig transgenes were bred onto the NZB background to generate double transgenic (dTg) mice. NZB dTg mice had elevated levels of anti-HEL antibodies, despite apparently normal B cell functional anergy in-vitro. NZB dTg B cells also demonstrated increased survival and abnormal entry into the follicular compartment following transfer into sHEL mice. Since this process is dependent on BAFF, BAFF serum and mRNA levels were assessed and were found to be significantly elevated in NZB dTg mice. Treatment of NZB sHEL recipient mice with TACI-Ig reduced NZB dTg B cell survival following adoptive transfer, confirming the role of BAFF in this process. Although NZB mice had modestly elevated BAFF, the enhanced NZB B cell survival response appeared to result from an altered response to BAFF. In contrast, T cell blockade had a minimal effect on B cell survival, but inhibited anti-HEL antibody production. The findings suggest that the modest BAFF elevations in NZB mice are sufficient to perturb B cell tolerance, particularly when acting in concert with B cell functional abnormalities and T cell help.

Disruption of nNOS-PSD95 protein-protein interaction inhibits acute thermal hyperalgesia and chronic mechanical allodynia in rodents

BACKGROUND AND PURPOSE

Post-synaptic density protein 95 (PSD95) contains three PSD95/Dosophilia disc large/ZO-1 homology domains and links neuronal nitric oxide synthase (nNOS) with the N-methyl-D-aspartic acid (NMDA) receptor. This report assesses the effects of disruption of the protein-protein interaction between nNOS and PSD95 on pain sensitivity in rodent models of hyperalgesia and neuropathic pain.

EXPERIMENTAL APPROACH

We generated two molecules that interfered with the nNOS-PSD95 interaction: IC87201, a small molecule inhibitor; and tat-nNOS (residues 1-299), a cell permeable fusion protein containing the PSD95 binding domain of nNOS. We then characterized these inhibitors using in vitro and in vivo models of acute hyperalgesia and chronic allodynia, both of which are thought to require nNOS activation.

KEY RESULTS

IC87201 and tat-nNOS (1-299) inhibited the in vitro binding of nNOS with PSD95, without inhibiting nNOS catalytic activity. Both inhibitors also blocked NMDA-induced 3',5'-cyclic guanosine monophosphate (cGMP) production in primary hippocampal cultures. Intrathecal administration of either inhibitor potently reversed NMDA-induced thermal hyperalgesia in mice. At anti-hyperalgesic doses, there was no effect on acute pain thresholds or motor coordination. Intrathecal administration of IC87201 and tat-nNOS also reversed mechanical allodynia induced by chronic constriction of the sciatic nerve.

CONCLUSIONS AND IMPLICATIONS

nNOS-PSD95 interaction is important in maintaining hypersensitivity in acute and chronic pain. Disruption of the nNOS-PSD95 interaction provides a novel approach to obtain selective anti-hyperalgesic compounds.

A B cell intrinsic defect initiates autoimmunity in New Zealand Black chromosome 13 congenic mice (49.21)

Introgression of a New Zealand Black (NZB) chromosome 13 (c13) interval onto a lupus-resistant C57BL/6 (B6) background (denoted, B6.NZBc13) is sufficient to produce many of the hallmarks of lupus. To characterize the immune defects leading to these abnormalities observed in B6.NZBc13 mice, bone marrow (BM) chimeras and BCR transgenic mice were produced. In BM chimeras, transfer of B6.NZBc13 BM cells was sufficient to transfer autoimmunity. Interestingly, in mixed BM chimeras the abnormal T and B cell activation as well as DC expansion was observed in both B6 and B6.NZBc13 derived cells; but with greater B cell activation in B6.NZBc13 derived cells. When an anti-HEL Ig transgene was crossed onto the congenic background disease was abrogated and the abnormal cellular phenotypes normalized. Although tolerance was retained in anti-HEL Ig/soluble HEL double transgenic mice, increased numbers of 'edited' cells were seen in the periphery. B cell function studies revealed altered phosphorylation of signaling molecules downstream of the BCR. These findings indicate the presence of a BM-cell intrinsic defect on NZB c13 that can be localized to a B cell defect, which is necessary to initiate the autoimmune phenotype in B6.NZBc13 mice.

Accuracy of body image perception and preferred weight loss strategies in schizophrenia: a controlled pilot study

OBJECTIVE

Obesity in severely mentally ill (SMI) populations is an increasing problem, but there is no controlled data regarding the relationship between SMI and weight perception.

METHOD

Fifty patients with schizophrenia and 50 demographically matched control participants were recruited. Weight, height, and body image accuracy were assessed for all participants, and assessments of mood, psychotic symptom severity and anxiety, and preferred modes of weight loss were assessed for the schizophrenia sample.

RESULTS

Patients with schizophrenia were significantly more likely to be obese than controls (46% vs. 18%, P < 0.005), and most patients expressed an interest in losing weight. Obese participants with schizophrenia underestimated their body size (11.0%) more than controls (4.9%) (P < 0.05).

CONCLUSION

Patients with schizophrenia are more likely to underestimate their body size, independent of the effects of obesity. However, they also express concern about weight issues and willingness to participate in psychoeducational groups targeted at weight loss.

Dissociation of the genetic loci leading to b1a and NKT cell expansions from autoantibody production and renal disease in B6 mice with an introgressed New Zealand Black chromosome 4 interval

Previous mapping studies have linked New Zealand Black (NZB) chromosome 4 to several lupus traits, including autoantibody production, splenomegaly, and glomerulonephritis. To confirm the presence of these traits, our laboratory introgressed homozygous NZB chromosome 4 intervals extending from either 114 to 149 Mb or 32 to 149 Mb onto the lupus-resistant C57BL/6 background (denoted B6.NZBc4S and B6.NZBc4L, respectively). Characterization of aged cohorts revealed that B6.NZBc4L mice exhibited a striking increase in splenic B1a and NKT cells in the absence of high titer autoantibody production and significant renal disease. Tissue-specific expansion of these subsets was also seen in the peritoneum and liver for B1a cells and in the bone marrow for NKT cells. Staining with CD1d tetramers loaded with an alpha-galactosylceramide analog (PBS57) demonstrated that the expanded NKT cell population was mainly CD1d-dependent NKT cells. The lack of both cellular phenotypes in B6.NZBc4S mice demonstrates that the genetic polymorphism(s) that result in these phenotypes are on the proximal region of NZB chromosome 4. This study confirms the presence of a locus that promotes the expansion of B1a cells and newly identifies a region that promotes CD1d-restricted NKT cell expansion on NZB chromosome 4. Taken together, the data indicate that neither an expansion of B1a cells and/nor NKT cells is sufficient to promote autoantibody production and ultimately, renal disease.

Colocalization of Expansion of the Splenic Marginal Zone Population with Abnormal B Cell Activation and Autoantibody Production in B6 Mice with an Introgressed New Zealand Black Chromosome 13 Interval

Polyclonal B cell activation is a prominent feature of the lupus-prone New Zealand Black (NZB) mouse strain. We have previously demonstrated linkage between a region on NZB chromosome 13 and increased costimulatory molecule expression on B cells. In this study we have produced C57BL/6 congenic mice with an introgressed homozygous NZB interval extending from approximately 24 to 73 cM on chromosome 13 (denoted B6.NZBc13). We show that B6.NZBc13 female mice not only have enhanced B cell activation but also share many other B cell phenotypic characteristics with NZB mice, including expansion of marginal zone and CD5+ B cell populations, increased numbers of IgM ELISPOTs, and increased serum levels of total IgM and IgM autoantibodies. In addition these mice have increased T cell activation, increased numbers of germinal centers, mild glomerulonephritis, and produce high-titer IgM and IgG anti-chromatin Abs. Male B6.NZBc13 mice have a less pronounced cellular phenotype, lacking expansion of the marginal zone B cell population and IgG anti-chromatin Ab production, indicating the presence of gender dimorphism for this locus. Thus, we have identified a genetic locus that recapitulates with fidelity the B cell phenotypic abnormalities in NZB mice, and we demonstrate that this locus is sufficient to induce an autoimmune phenotype. The data provide further support to the contention that immune abnormalities leading to altered B cell activation and selection contribute to the development of autoimmunity in NZB mice.

June 2003: 33-year-old male with a frontal lobe mass

The June 2003 COM. A 33-year-old male with a history of seizures was found to have an intra- and extra-axial frontal lobe mass. The histology of the resected tumor showed a meningioma with underlying meningioangiomatosis. Meningioangiomatosis (MA) is a benign intracortical plaque-like proliferation of meningothelial cells, microvasculature and fibroblast-like cells probably of hamartomatous origin. Very rarely, MA is associated with an overlying meningioma as in this case. When MA is accompanied by a meningioma, it is generally not associated with clinical evidence of neurofibromatosis. It is important to distinguish MA from an invasive meningioma, because of its favorable prognosis after resection.

The evaluation of a sexual assault risk reduction program: a multisite investigation

This article summarizes the results of the Ohio University Sexual Assault Risk Reduction Project, which is a program designed to reduce college women's risk for sexual assault. The program was evaluated at 2 separate universities with 762 women. Participants were randomly assigned either to the program or to the no-treatment comparison group, and they completed measures that assessed sexual victimization, dating behaviors, sexual communication, and rape empathy at the pretest and at the 2-month and 6-month follow-ups. At the 2-month follow-up, there were no differences between the groups on any of the outcome measures. However, those women who were moderately victimized during the 2-month follow-up were significantly less likely to be revictimized during the 6-month follow-up period if they participated in the program.

The evaluation of a sexual assault risk reduction program: a multisite investigation

This article summarizes the results of the Ohio University Sexual Assault Risk Reduction Project, which is a program designed to reduce college women's risk for sexual assault. The program was evaluated at 2 separate universities with 762 women. Participants were randomly assigned either to the program or to the no-treatment comparison group, and they completed measures that assessed sexual victimization, dating behaviors, sexual communication, and rape empathy at the pretest and at the 2-month and 6-month follow-ups. At the 2-month follow-up, there were no differences between the groups on any of the outcome measures. However, those women who were moderately victimized during the 2-month follow-up were significantly less likely to be revictimized during the 6-month follow-up period if they participated in the program.

Cerium and lanthanum promote floral initiation and reproductive growth of Arabidopsis thaliana

The effects of cerium and lanthanum on the vegetative growth, floral initiation and reproductive growth of Arabidopsis thaliana were studied. Addition of cerium nitrate (0.5-10 µM) or lanthanum nitrate (0.5-50 µM) to the culture medium significantly increased the lengths of primary roots, but had no significant effects on the number of rosette leaves produced per plant, plant heights and dry weights during the vegetative growth stage (17 days after seed germination). The percentage of plants bolted was significantly increased with the addition of 0.5-10.0 µM cerium nitrate or lanthanum nitrate. The combination of 0.5 µM cerium nitrate and 0.5 µM lanthanum nitrate was found to be most effective on the induction of floral initiation. The height, dry weight and average number of flower numbers of 35-day-old plants growing in media containing cerium nitrate or/and lanthanum nitrate (0.5-10.0 µM) were found to be significantly higher than those in the control medium. The endogenous levels of cytokinins (zeatin riboside, dihydrozeatin riboside and isopentenyl adenosine) and carbohydrates (sucrose, glucose and fructose) in leaf and root tissues of plants growing in the medium supplemented with 0.5 µM cerium nitrate and 0.5 µM lanthanum nitrate were not significantly different from those of plants in the control medium. Application of 0.5 µM cerium nitrate and 0.5 µM lanthanum nitrate enhanced the effects of 10(-6) M IPA on root growth, plant height and flowering. The role of cerium and lanthanum in promoting floral initiation and reproductive growth and the possibility of developing non-hormonal flowering promoting agents are discussed.

AKAP79 inhibits calcineurin through a site distinct from the immunophilin-binding region

Targeting of protein kinases and phosphatases provides additional specificity to substrate selectivity in cellular signaling. In the case of the Ca2+/calmodulin-dependent protein phosphatase calcineurin, AKAP79 has been shown to bind calcineurin and inhibit its activity in vitro (Coghlan, V., Perrino, B. A., Howard, M., Langeberg, L. K., Hicks, J. B., Gallatin, W. M., and Scott, J. D. (1995) Science 267, 108-111). In the present study, we characterized the binding regions on calcineurin A (CnA) and AKAP79 that are important for this interaction. Residues 30-98 and 311-336 on CnA, and residues 108-280 on AKAP79 were found to be important for binding. The binding of CnA by AKAP79 does not require the calcineurin B subunit, and occurs in a region distinct from where the immunosuppressant-immunophilin complex bind. AKAP79 also bound to CnA in cells transfected with AKAP79 and CnA. To determine the function of AKAP79-calcineurin interaction in intact cells, we measured the dephosphorylation and subsequent activation of NFAT, a transcription factor that is a substrate for calcineurin. Overexpression of AKAP79 inhibited NFAT dephosphorylation, resulting in a decrease in NFAT activation. These results demonstrated that AKAP79 can bind to and inhibit calcineurin activity in vivo, suggesting a physiological role for AKAP79-calcineurin interaction in NFAT-mediated signaling.

Cabin 1, a negative regulator for calcineurin signaling in T lymphocytes

Calcineurin plays a pivotal role in the T cell receptor (TCR)-mediated signal transduction pathway and serves as a common target for the immunosuppressants FK506 and cyclosporin A. We report the identification of a novel endogenous calcineurin binding protein named Cabin 1 that inhibits calcineurin-mediated signal transduction. The interaction between Cabin 1 and calcineurin is dependent on PKC activation. Overexpression of Cabin 1 or its N-terminal truncation mutants inhibits the transcriptional activation of calcineurin-responsive elements in the interleukin-2 promoter and blocks dephosphorylation of NF-AT upon T cell activation. These results suggest a negative regulatory role for Cabin 1 in calcineurin signaling and provide a possible mechanism of feedback inhibition of TCR signaling through cross-talk between protein kinases and calcineurin.

Enhanced potency of perfluorinated thalidomide derivatives for inhibition of LPS-induced tumor necrosis factor-alpha production is associated with a change of mechanism of action

Perfluorination of phthalimides leads to dramatically increased potency as inhibitors of TNF-alpha production. We examined the enantiodependence for several tetrafluorophthalimides and alpha-methylthalidomide, 3. Only 3 exhibited strikingly enantiodependent activity. The key structural determinant for the enhanced activity is the tetrafluorophthaloyl group, which confers enhanced potency and a change in the mechanism of inhibition.

Effect of photodynamic therapy in combination with mitomycin C on a mitomycin-resistant bladder cancer cell line

Photodynamic therapy is a method for treating cancer using drugs activated by light. A new compound, 5-aminolaevulinic acid (ALA), is a precursor of the active photosensitizer protoporphyrin IX (PpIX) and has fewer side-effects and much more transient phototoxicity than previous photosensitizers. Cell survival of ALA-mediated photodynamic therapy was measured in the J82 bladder cancer cell line, along with its mitomycin C-resistant counterpart J82/MMC. This demonstrated that mitomycin resistance is not cross-resistant to photodynamic therapy. There was also a suggestion that the mitomycin-resistant cells were more susceptible to photodynamic therapy than the parent cell line. Photodynamic therapy appeared to enhance the effect of mitomycin C, when mitomycin C was given first. This phenomenon was apparent for both drug-resistant and drug-sensitive cell lines. This suggests a possible role for combined mitomycin C and photodynamic therapy in superficial bladder tumours that have recurred despite intravesical cytotoxic drug treatment.

T-cell receptor stimulation elicits an early phase of activation and a later phase of deactivation of the transcription factor NFAT1

We show here that NFAT1 is rapidly activated, then slowly deactivated, by stimulation of T cells through their antigen receptor. Within minutes of T-cell receptor stimulation, NFAT1 is dephosphorylated, translocates from the cytoplasm into the nucleus, and shows an increase in its ability to bind to DNA. These changes are dependent on calcium mobilization and calcineurin activation, since they are also elicited by ionomycin and are blocked by the immunosuppressive drug cyclosporin A. After several hours of T-cell receptor stimulation, the majority of the NFAT1 in the cell reverts to its original phosphorylated form, reappears in the cytoplasm, and again displays a low affinity for DNA. Deactivation of NFAT1 is facilitated by phorbol 12-myristate 13-acetate and inhibitors of capacitative calcium entry and most likely reflects the slow return of intracellular free calcium concentrations towards resting levels. Our results suggest that calcineurin-dependent signalling pathways mediate the early activation of NFAT1, while phorbol 12-myristate 13-acetate-dependent feedback pathways contribute to the late deactivation. Persistent NFAT-dependent cytokine gene transcription in activated T cells may be mediated by other NFAT family proteins in addition to NFAT1 during the immune response.

Calcineurin binds the transcription factor NFAT1 and reversibly regulates its activity

NFAT1 (previously termed NFATp) is a cytoplasmic transcription factor involved in the induction of cytokine genes. We have previously shown that the dephosphorylation of NFAT1, accompanied by its nuclear translocation and increased DNA binding activity, is regulated by calcium- and calcineurin-dependent mechanisms, as each of these hallmarks of NFAT1 activation is elicited by ionomycin and blocked by the immunosuppressive drugs cyclosporin A and FK506 (Shaw, K.T.-Y., Ho, A.M., Raghavan, A., Kim, J., Jain, J., Park, J., Sharma, S., Rao, A., and Hogan, P.G. (1995) Proc. Natl. Acad. Sci. U.S.A. 92, 11205-11209). Here we show that the activation state of NFAT1 in T cells is remarkably sensitive to the level of calcineurin activity. Addition of cyclosporin A, even in the presence of ongoing ionomycin stimulation, results in rephosphorylation of NFAT1, its reappearance in the cytoplasm, and a return of its DNA binding activity to low levels. Similar effects are observed upon removal of ionomycin or addition of EGTA. We also demonstrate a direct interaction between calcineurin and NFAT1 that is consistent with a direct enzyme-substrate relation between these two proteins and that may underlie the sensitivity of NFAT1 activation to the level of calcineurin activity. The NFAT1-calcineurin interaction, which involves an N-terminal region of NFAT1 conserved in other NFAT family proteins, may provide a target for the design of novel immunosuppressive drugs.