Shawn Jensen - Academia.edu (original) (raw)

Papers by Shawn Jensen

Research paper thumbnail of Cancer's Dark Matter: Lighting the Abyss Unveils Universe of New Therapies

Clinical Cancer Research, Apr 11, 2023

Research paper thumbnail of OX40 agonist stimulation increases and sustains humoral and cell-mediated responses to SARS-CoV-2 protein and saRNA vaccines

Frontiers in Immunology, Sep 27, 2022

To prevent SARS-CoV-2 infections and generate long-lasting immunity, vaccines need to generate st... more To prevent SARS-CoV-2 infections and generate long-lasting immunity, vaccines need to generate strong viral-specific B and T cell responses. Previous results from our lab and others have shown that immunizations in the presence of an OX40 agonist antibody lead to higher antibody titers and increased numbers of long-lived antigen-specific CD4 and CD8 T cells. Using a similar strategy, we explored the effect of OX40 co-stimulation in a prime and boost vaccination scheme using an adjuvanted SARS-CoV-2 spike protein vaccine in C57BL/6 mice. Our results show that OX40 engagement during vaccination significantly increases long-lived antibody responses to the spike protein. In addition, after immunization spike protein-specific proliferation was greatly increased for both CD4 and CD8 T cells, with enhanced, spike-specific secretion of IFN-g and IL-2. Booster (3 rd injection) immunizations combined with an OX40 agonist (7 months post-prime) further increased vaccine-specific antibody and T cell responses. Initial experiments assessing a self-amplifying mRNA (saRNA) vaccine encoding the spike protein antigen show a robust antigen-specific CD8 T cell response. The saRNA spike-specific CD8 T cells express high levels of GrzmB, IFN-g and TNF-a which was not observed with protein immunization and this response was further increased by the OX40 agonist. Similar to protein immunizations the OX40 agonist also increased vaccine-specific CD4 T cell responses. In summary, this study compares and contrasts the effects and benefits of both protein and saRNA vaccination and the extent to which an OX40 agonist enhances and sustains the immune response against the SARS-CoV-2 spike protein.

Research paper thumbnail of 443 An immunotherapy trio in advanced HNSCC for coordinated B and T cell antigen response

Journal for ImmunoTherapy of Cancer, 2020

BackgroundOutcomes for recurrent or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC... more BackgroundOutcomes for recurrent or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) are dismal and responses to anti-PD-1 appear best in tumors with PD-1+ T cells in proximity to PD-L1+ cells, arguing that improved outcome is associated with a pre-existing anti-cancer immune response. Based on this, we hypothesize that vaccines which prime and/or expand T cells to a spectrum of antigens overexpressed by HNSCC combined with T cell agonists, like anti-GITR, that provide costimulatory signals will improve the anti-PD-1 response rates. We have developed a cancer vaccine, DPV-001, that contains more than 300 proteins for genes overexpressed by HNSCC, encapsulated in a CLEC9A-targeted microvesicle and containing TLR/NOD agonists and DAMPs. Recently, we reported that combining anti-GITR + vaccine + anti-PD-1 augmented therapeutic efficacy in a preclinical model and now plan a phase 1b trial of this combination in patients with advanced HNSCC.MethodsSera from patients receivi...

Research paper thumbnail of Abstract CT502: Preliminary immunological monitoring of first-in-human immunotherapy-trio for advanced head and neck squamous cell carcinoma

Cancer Research

Background: Preclinical studies document that complex cancer vaccines, combined with T cell agoni... more Background: Preclinical studies document that complex cancer vaccines, combined with T cell agonists and anti-PD-1, can augment therapeutic efficacy. Here we report preliminary immunological analyses of patients enrolled in a first-in-human immunotherapy-trio study of multivalent autophagosome vaccine (DPV-001), with sequenced checkpoint inhibition (anti-PD-1; retifanlimab), with/without anti-GITR agonist (INCAGN-1949), in recurrent or metastatic HNSCC (NCT04470024). Methods: Peripheral blood (PB) and sera are collected regularly and PB are evaluated by flow cytometry. Biopsies obtained at baseline, D15 and D45 are analyzed by multiplex IF and 10x Genomics scRNA-Seq. Sera are being analyzed by phage immunoprecipitation (PhIP) sequencing for reactivity against the human proteome. Results: Preliminary results document increases in activated CD4 and CD8 effector memory T cells (TEM) with vaccine alone. Changes in tumor microenvironment (TEM) were also observed with increased infiltrati...

Research paper thumbnail of Multispectral Fluorescence Imaging Allows for Distinctive Topographic Assessment and Subclassification of Tumor-Infiltrating and Surrounding Immune Cells

Methods in Molecular Biology

Histomorphology has significantly changed over the last decades due to technological achievements... more Histomorphology has significantly changed over the last decades due to technological achievements in immunohistochemistry (IHC) for the visualization of specific proteins and in molecular pathology, particularly in the field of in situ hybridization of small oligonucleotides and amplification of DNA and RNA amplicons. With an increased availability of suitable methods, the demands regarding the observer of histomorphological slides were the supply of complex quantitative data as well as more information about protein expression and cell-cell interactions in tissue sections. Advances in fluorescence-based multiplexed IHC techniques, such as multispectral imaging (MSI), allow the quantification of multiple proteins at the same tissue section. In histopathology, it is a well-known technique for over a decade yet harboring serious problems concerning quantitative preciseness and tissue autofluorescence of multicolor staining when using formalin-fixed, paraffin-embedded (FFPE) tissue specimen. In recent years, milestones in tissue preparation, fluorescent dyes, hardware imaging, and software analysis were achieved including automated tissue segmentation (e.g., tumor vs. stroma) as well as in cellular and subcellular multiparameter analysis.This chapter covers the role that MSI plays in anatomic pathology for the analysis of FFPE tissue sections, discusses the technical aspects of MSI, and provides a review of its application in the characterization of immune cell infiltrates and beyond regarding its prognostic and predictive value and its use for guidance of clinical decisions for immunotherapeutic strategies.

Research paper thumbnail of Open-source digital image analysis of whole-slide multiplex immunohistochemistry

Successful digital image analysis (DIA) of cancer tissue is accurate and reproducible. These poin... more Successful digital image analysis (DIA) of cancer tissue is accurate and reproducible. These points of emphasis have brought procedures like the tissue microarray (TMA) and hotspot regions of interest (ROI) under scrutiny. The nature in which a pathologist selects TMAs and ROIs is conducive to bias. Whole Slide Imaging (WSI) offers a solution in its unbiased region selection and consideration of a larger tissue sample. However, options for software that can handle such large throughput are scarce. Additionally, while multiplex immunohistochemistry (mIHC) is becoming popular (Feng et al.), documentation of its digital analysis tools remains minimal. The combination of these procedures potentiates a deeper understanding of the tumor microenvironment. This study presents the whole-slide mIHC analysis capabilities of QuPath, an open-source application developed at Queen's University Belfast . Methods. A multiplex fluorescent stain panel was performed on patient samples. The slides w...

Research paper thumbnail of In MCA-induced sarcoma models, booster vaccination with GM-CSF-secreting whole-cell tumor vaccines maintain or improve efficacy but may alter trafficking of tumor-specific T cells (VAC13P.1128)

Journal of Immunology, 2015

Previously, we reported that while a single vaccination effectively generated therapeutic tumor-s... more Previously, we reported that while a single vaccination effectively generated therapeutic tumor-specific T cells for adoptive immunotherapy (AIT), repeated vaccination with the poorly immunogenic B16BL6 melanoma, modified to secrete GM-CSF, induced high levels of CD4 + FoxP3 + T regulatory (T reg ) cells and AIT with spleen cells was non-therapeutic. The effect could be overcome by transient depletion of CD4 + T cells, confirming the effect of T reg cells. Here experiments were performed to test whether this suppressive effect was observed in active-specific protection in 2 sarcoma models, MCA-304 and MCA-310. Mice were vaccinated once or thrice with either irradiated parental sarcoma or that sarcoma expressing GM-CSF. We did not observe significant changes in percentage or total count of splenic T reg cells under any conditions, however, tumor-specific IFN-γ release decreased in mice thrice vaccinated with GM-CSF-secreting tumors compared to parental (p

Research paper thumbnail of Preliminary evaluation of a novel whole slide multispectral assessment of seven markers: Potential to minimize bias in the characterization of the tumor immune environment

PD-L1 expression and TMB enrich for patients that respond to checkpoint blockade, but these evalu... more PD-L1 expression and TMB enrich for patients that respond to checkpoint blockade, but these evaluations are only a component of the entire story. Recently, our lab reported that evaluation of specific cell-cell relationships provided a powerful biomarker for overall survival in patients with HPVhead and neck cancer (HNSCC). However, the areas selected for analysis were operator selected “hot spots”. This approach introduces the potential for unconscious bias in the selection process. To address this, we have sought to perform whole slide evaluations of sections to compare with hot spot analysis. This study is a preliminary report applying a novel set of fluorophores and filters that allow the visualization of seven colors on a whole slide. Tissue samples included pellets of cultured lymphocytes and tumor specimens. A sample of the cultured lymphocytes that were fixed and embedded were analyzed by flow cytometry for immune markers. Formalin-fixed paraffin embedded (FFPE) sections wer...

Research paper thumbnail of Novel strategy increases capacity of tumor vaccine to provide cross-protection against unique MCA-induced sarcomas

Cancer Research, 2008

AACR Annual Meeting-- Apr 12-16, 2008; San Diego, CA 2847 Vaccination with irradiated 3-Methylcho... more AACR Annual Meeting-- Apr 12-16, 2008; San Diego, CA 2847 Vaccination with irradiated 3-Methylcholanthrene (MCA)-induced tumor cells provides protection from a subsequent viable challenge with the same MCA tumor, but not other MCA-induced tumors. This observation of unique tumor-specific protection, first reported in 1957 by Prehn and Main, has been well documented by numerous laboratories, including ours and is a well-established paradigm in tumor immunology. We postulated that all MCA-induced sarcomas overexpress some genes in common, but only the unique tumor-rejection antigens are stable enough to be cross-presented and induce antitumor immunity. We further postulated that the overexpressed genes common to most/all sarcomas are proteins with a very short half-life, such as Defective Ribosomal Proteins (DRiPs) and Short-Lived Proteins (SLiPS), which are not cross-presented due to their transient nature. Recently we (H. Hu, manuscript submitted) developed a strategy where DRiPs an...

Research paper thumbnail of Phosphorylation of SMAD3 in immune cells predicts survival of patients with early stage non-small cell lung cancer

Journal for ImmunoTherapy of Cancer, 2021

BackgroundThe interplay of immune and cancer cells takes place in the tumor microenvironment wher... more BackgroundThe interplay of immune and cancer cells takes place in the tumor microenvironment where multiple signals are exchanged. The transforming growth factor beta (TGFB) pathway is known to be dysregulated in lung cancer and can impede an effective immune response. However, the exact mechanisms are yet to be determined. Especially which cells respond and where does this signaling take place with respect to the local microenvironment.MethodsHuman non-small cell lung cancer samples were retrospectively analyzed by multiplexed immunohistochemistry for SMAD3 phosphorylation and programmed death ligand 1 expression in different immune cells with respect to their localization within the tumor tissue. Spatial relationships were studied to examine possible cell-cell interactions and analyzed in conjunction with clinical data.ResultsTGFB pathway activation in CD3, CD8, Foxp3 and CD68 cells, as indicated by SMAD3 phosphorylation, negatively impacts overall and partially disease-free survi...

Research paper thumbnail of 383 Durable responses with intratumoral electroporation of plasmid interleukin 12 plus pembrolizumab in patients with advanced melanoma progressing on an anti-PD-1 antibody: updated data from keynote 695

Journal for ImmunoTherapy of Cancer, 2021

BackgroundElectroporated plasmid interleukin-12 (pIL-12-EP; tavokinogene telseplasmid; TAVO) indu... more BackgroundElectroporated plasmid interleukin-12 (pIL-12-EP; tavokinogene telseplasmid; TAVO) induces sustained intratumoral expression of IL-12, a cytokine that is integral for response to anti-PD-1 antibodies. Here, we present updated safety and response duration data from KEYNOTE 695, a Phase 2, multicenter, open-label trial of pIL-12-EP in combination with pembrolizumab in patients with stage III/IV melanoma immediately following confirmed progression on an anti-PD-1 antibody.MethodsPatients with confirmed disease progression after ≥12 weeks‘ treatment with an anti-PD-1 antibody alone or in combination were eligible. Patients received intratumoral pIL-12-EP on days 1, 5 and 8 every 6 weeks and pembrolizumab 200 mg every 3 weeks. Responses were assessed by the investigator at 12-week intervals using RECIST v1.1; overall survival (OS) and duration of response (DoR) assessments were conducted using the Kaplan-Meier method.ResultsOf the first 56 patients treated, 50% had visceral dis...

Research paper thumbnail of Intratumoral Plasmid IL12 Expands CD8+ T Cells and Induces a CXCR3 Gene Signature in Triple-negative Breast Tumors that Sensitizes Patients to Anti–PD-1 Therapy

Clinical Cancer Research, 2021

Purpose: Triple-negative breast cancer (TNBC) is an aggressive disease with limited therapeutic o... more Purpose: Triple-negative breast cancer (TNBC) is an aggressive disease with limited therapeutic options. Antibodies targeting programmed cell death protein 1 (PD-1)/PD-1 ligand 1 (PD-L1) have entered the therapeutic landscape in TNBC, but only a minority of patients benefit. A way to reliably enhance immunogenicity, T-cell infiltration, and predict responsiveness is critically needed. Patients and Methods: Using mouse models of TNBC, we evaluate immune activation and tumor targeting of intratumoral IL12 plasmid followed by electroporation (tavokinogene telseplasmid; Tavo). We further present a single-arm, prospective clinical trial of Tavo monotherapy in patients with treatment refractory, advanced TNBC (OMS-I140). Finally, we expand these findings using publicly available breast cancer and melanoma datasets. Results: Single-cell RNA sequencing of murine tumors identified a CXCR3 gene signature (CXCR3-GS) following Tavo treatment associated with enhanced antigen presentation, T-cell...

Research paper thumbnail of Multi-institutional TSA-amplified Multiplexed Immunofluorescence Reproducibility Evaluation (MITRE) Study

Journal for ImmunoTherapy of Cancer, 2021

BackgroundEmerging data suggest predictive biomarkers based on the spatial arrangement of cells o... more BackgroundEmerging data suggest predictive biomarkers based on the spatial arrangement of cells or coexpression patterns in tissue sections will play an important role in precision immuno-oncology. Multiplexed immunofluorescence (mIF) is ideally suited to such assessments. Standardization and validation of an end-to-end workflow that supports multisite trials and clinical laboratory processes are vital. Six institutions collaborated to: (1) optimize an automated six-plex assay focused on the PD-1/PD-L1 axis, (2) assess intersite and intrasite reproducibility of staining using a locked down image analysis algorithm to measure tumor cell and immune cell (IC) subset densities, %PD-L1 expression on tumor cells (TCs) and ICs, and PD-1/PD-L1 proximity assessments.MethodsA six-plex mIF panel (PD-L1, PD-1, CD8, CD68, FOXP3, and CK) was rigorously optimized as determined by quantitative equivalence to immunohistochemistry (IHC) chromogenic assays. Serial sections from tonsil and breast carci...

Research paper thumbnail of 480 Preliminary evaluation of a novel coronavirus vaccine (CORVax) using electroporation of plasmid DNA encoding a stabilized prefusion SARS-CoV-2 spike protein alone or with transfection of plasmid IL-12

Regular and young investigator award abstracts, 2020

BackgroundSARS-CoV-2 (CoV2) has precipitated a global pandemic and the effectiveness of standard ... more BackgroundSARS-CoV-2 (CoV2) has precipitated a global pandemic and the effectiveness of standard vaccine strategies to induce potent and persistent immunity to CoV2 is in question, particularly for the elderly. This problem is not dissimilar to what we have struggled with in our quest to induce immunity to cancer antigens, where vaccine-induced anti-cancer immune responses can be weak. Here, we describe a novel vaccine approach which leverages electroporation (EP) of a plasmid encoding a prefusion stabilized CoV2 spike protein (CORVax). As IL-12 has been shown to augment the efficacy of immunotherapy in aged mice,1 we have initiated studies to evaluate if plasmid IL-12 (TAVO™) can similarly augment anti-CoV2 immune responses in young mice and have planned studies in aged animals.MethodsA prefusion stabilized CoV2 spike plasmid expression vector was constructed, a master cell bank generated and clinical-grade plasmid manufactured. C57BL/6 and BALB/c were vaccinated via intramuscular ...

Research paper thumbnail of SARS-CoV-2 antibodies detected in human breast milk post-vaccination

ABSTRACTImportanceThe SARS-CoV-2 pandemic has infected over a hundred million people worldwide, w... more ABSTRACTImportanceThe SARS-CoV-2 pandemic has infected over a hundred million people worldwide, with almost 2.5 million deaths at the date of this publication. In the United States, Pfizer-BioNTech and Moderna vaccines were first administered to the public starting in December 2020, and no lactating women were included in the initial trials of safety/efficacy. Research on SARS-CoV-2 vaccination in lactating women and the potential transmission of passive immunity to the infant through breast milk is needed to guide patients, clinicians and policy makers during the worldwide effort to curb the spread of this virus.ObjectiveTo determine whether SARS-CoV-2 specific immunoglobins are found in breast milk post-vaccination, and to characterize the time course and types of immunoglobulins present.DesignProspective cohort studySettingProvidence Portland Medical Center, Oregon, USAParticipantsSix lactating women who planned to receive both doses of the Pfizer-BioNTech or Moderna vaccine betw...

Research paper thumbnail of 799 Durable responses and immune activation with intratumoral electroporation of pIL-12 plus pembrolizumab in actively progressing anti-PD-1 refractory advanced melanoma: KEYNOTE 695 interim data

Late-breaking abstracts, 2020

BackgroundElectroporated plasmid IL-12 (TAVO or tavokinogene telseplasmid) is a novel pro-inflamm... more BackgroundElectroporated plasmid IL-12 (TAVO or tavokinogene telseplasmid) is a novel pro-inflammatory intratumoral therapy with substantial single agent activity in melanoma, which has been shown to synergize with anti-PD-1 antibodies in patients predicted as non-responders to anti-PD-1.1 2 Interim data from patients with stage III/IV melanoma actively progressing on anti-PD-1 antibody are presented herein.MethodsPatients with confirmed disease progression by RECIST v1.1 after at least 12 weeks of treatment on pembrolizumab or nivolumab (or combination checkpoint blockade) and within 12 weeks of last dose (with no intervening therapies) were enrolled. There was no limit on the number of prior lines of therapy. At least one accessible lesion was electroporated with plasmid IL-12 (pIL-12-EP) on days 1, 5 and 8 every 6 weeks and pembrolizumab was administered every 3 weeks. Tumor response in treated and untreated lesions was assessed by RECIST v1.1 every 12 weeks. Endpoints include OR...

Research paper thumbnail of Heterodimeric IL-15 delays tumor growth and promotes intratumoral CTL and dendritic cell accumulation by a cytokine network involving XCL1, IFN-γ, CXCL9 and CXCL10

Journal for ImmunoTherapy of Cancer, 2020

BackgroundInterleukin-15 (IL-15) promotes growth and activation of cytotoxic CD8+T and natural ki... more BackgroundInterleukin-15 (IL-15) promotes growth and activation of cytotoxic CD8+T and natural killer (NK) cells. Bioactive IL-15 is produced in the body as a heterodimeric cytokine, comprising the IL-15 and IL-15 receptor alpha chains (hetIL-15). Several preclinical models support the antitumor activity of hetIL-15 promoting its application in clinical trials.MethodsThe antitumor activity of hetIL-15 produced from mammalian cells was tested in mouse tumor models (MC38 colon carcinoma and TC-1 epithelial carcinoma). The functional diversity of the immune infiltrate and the cytokine/chemokine network within the tumor was evaluated by flow cytometry, multicolor immunohistochemistry (IHC), gene expression profiling by Nanostring Technologies, and protein analysis by electrochemiluminescence and ELISA assays.ResultshetIL-15 treatment resulted in delayed primary tumor growth. Increased NK and CD8+T cell tumoral infiltration with an increased CD8+/Treg ratio were found by flow cytometry a...

Research paper thumbnail of Effect of various decontamination procedures on disposable N95 mask integrity and SARS-CoV-2 infectivity

The COVID-19 pandemic has created a high demand on personal protective equipment, including dispo... more The COVID-19 pandemic has created a high demand on personal protective equipment, including disposable N95 masks. Given the need for mask reuse, we tested the feasibility of vaporized hydrogen peroxide (VHP), ultraviolet light (UV), and ethanol decontamination strategies on N95 mask integrity and the ability to remove the infectious potential of SARS-CoV-2. FIT test data showed functional degradation by both ethanol and UV decontamination to different degrees. VHP treated masks showed no significant change in function after two treatments. We also report a single SARS-CoV-2 virucidal experiment using Vero E6 cell infection. We hope our data will guide further research for evidenced-based decisions for disposable N95 mask reuse and help protect caregivers from SARS-CoV-2 and other pathogens.

Research paper thumbnail of Abstract LB-318: Multi-institutional TSA-amplified Multiplexed Immunofluorescence Reproducibility Evaluation (MITRE study): Reproducibility assessment of an automated multiplexed immunofluorescence slide staining, imaging, and analysis workflow

Tumor Biology, 2019

Background: Emerging data suggests that predictive biomarkers based on the spatial arrangement of... more Background: Emerging data suggests that predictive biomarkers based on the spatial arrangement of multiple cell types in FFPE tissue sections will be an important component of precision medicine in immune-oncology. Multiplexed immunofluorescence (mIF) facilitates such assessments. If mIF is to play a translational role in research and ultimately clinical practice, it is vital to refine, standardize, and validate an end-to-end workflow that supports large scale multi-site trials and clinical laboratory processes. To this end, six institutions collaborated to develop an automated 6-plex assay focused on the PD-1/PD-L1 axis and assessed its inter- and intra-site reproducibility. Specific attention was paid to assessment of %PD-L1 expression by immune cells (ICs), as pathologists have poor concordance for this parameter as noted in the Blueprint 2 and multi-institutional NCCN studies on PD-L1 IHC. Methods: A 7-color mIF panel (PD-L1, PD-1, CD8, CD68, FoxP3, Cytokeratin, and DAPI) was optimized on a Leica Bond Rx autostainer. Serial sections of tonsil and a lung cancer tissue-microarray (TMA), antibodies and TSA-Opal detection reagents (Akoya Biosciences) were distributed. Cell pellet arrays were also distributed and used to normalize batch variation in intensity measurements. Tonsil and TMA sections were stained at each site and imaged at 20x using a Vectra Polaris. Cells were segmented and phenotyped using image analysis algorithms. In tonsil sections, the average intensity of the top quartile of cells positive for each marker was assessed to identify potential variation in staining intensity. In lung TMAs, cell densities and %PD-L1 expression in immune cells (CD68+ and CD8+ cells) was determined. Results: The average staining intensity coefficients of variation (CV) for all markers within sites was 10% in tonsil samples. Inter-site concordance for tumor cell and immune cell subset densities in TMAs, had an average R2 value of 0.86 and slope of 0.96. Inter-site concordance for %PD-L1+ ICs had an average R2 value of 0.81, and slope of 0.82, in contrast to ICC values of Conclusions: We demonstrate a reproducible end-to-end process for mIF characterization of the PD-1/PD-L1 axis including automated staining, multispectral imaging, and machine-learning-trained image analysis algorithms. This approach improved reproducibility of %PD-L1 IC assessment and brought it in line with %PD-L1 tumor cell assessment by pathologists. Sources of variation were identified and will be discussed. The described approach may serve as a template for assessing reproducibility of emerging mIF panels for other investigative teams, with an eye toward translating such approaches into clinical trials and ultimately into the clinic. Citation Format: Clifford Hoyt, Kristin Roman, Liz Engle, Chichung Wang, Carmen Ballesteros-Merino, Shawn M. Jensen, John McGuire, Yi Zheng, Carla Coltharp, Mei Jiang, Justin Lucas, Edwin Parra, Ignacio Wistuba, Darren Locke, Bernard A. Fox, David L. Rimm, Janis Marie Taube. Multi-institutional TSA-amplified Multiplexed Immunofluorescence Reproducibility Evaluation (MITRE study): Reproducibility assessment of an automated multiplexed immunofluorescence slide staining, imaging, and analysis workflow [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-318.

Research paper thumbnail of Abstract LB-088: Heterodimeric IL-15 enhances tumor infiltration, persistence and effector functions of adoptively transferred tumor-specific T cells in the absence of lymphodepletion

Cancer Research, 2016

Adoptive cell transfer (ACT) is a promising immunotherapeutic approach for cancer. Lymphodepletio... more Adoptive cell transfer (ACT) is a promising immunotherapeutic approach for cancer. Lymphodepletion of the host is associated with favorable ACT outcomes but it may cause detrimental effects in humans. Lymphodepletion results in high level of homeostatic cytokines including Interleukin-15 (IL-15) that support survival and proliferation of the transferred lymphocytes. We tested the hypothesis that exogenous IL-15 enhances ACT in the absence of lymphodepletion. We have previously shown that bioactive IL-15 in vivo comprises a stable complex of the IL-15 chain with the IL-15 Receptor alpha chain, termed heterodimeric IL-15 (hetIL-15). We therefore evaluated the effects of the combination regimen ACT+hetIL-15 in absence of lymphodepletion by transferring melanoma-specific Pmel-1 T cells into B16 melanoma-bearing mice. hetIL-15 promoted infiltration and persistence of both adoptively transferred Pmel-1 cells and endogenous CD8+ T cells in the tumor. Following lymphodepletion by irradiatio...

Research paper thumbnail of Cancer's Dark Matter: Lighting the Abyss Unveils Universe of New Therapies

Clinical Cancer Research, Apr 11, 2023

Research paper thumbnail of OX40 agonist stimulation increases and sustains humoral and cell-mediated responses to SARS-CoV-2 protein and saRNA vaccines

Frontiers in Immunology, Sep 27, 2022

To prevent SARS-CoV-2 infections and generate long-lasting immunity, vaccines need to generate st... more To prevent SARS-CoV-2 infections and generate long-lasting immunity, vaccines need to generate strong viral-specific B and T cell responses. Previous results from our lab and others have shown that immunizations in the presence of an OX40 agonist antibody lead to higher antibody titers and increased numbers of long-lived antigen-specific CD4 and CD8 T cells. Using a similar strategy, we explored the effect of OX40 co-stimulation in a prime and boost vaccination scheme using an adjuvanted SARS-CoV-2 spike protein vaccine in C57BL/6 mice. Our results show that OX40 engagement during vaccination significantly increases long-lived antibody responses to the spike protein. In addition, after immunization spike protein-specific proliferation was greatly increased for both CD4 and CD8 T cells, with enhanced, spike-specific secretion of IFN-g and IL-2. Booster (3 rd injection) immunizations combined with an OX40 agonist (7 months post-prime) further increased vaccine-specific antibody and T cell responses. Initial experiments assessing a self-amplifying mRNA (saRNA) vaccine encoding the spike protein antigen show a robust antigen-specific CD8 T cell response. The saRNA spike-specific CD8 T cells express high levels of GrzmB, IFN-g and TNF-a which was not observed with protein immunization and this response was further increased by the OX40 agonist. Similar to protein immunizations the OX40 agonist also increased vaccine-specific CD4 T cell responses. In summary, this study compares and contrasts the effects and benefits of both protein and saRNA vaccination and the extent to which an OX40 agonist enhances and sustains the immune response against the SARS-CoV-2 spike protein.

Research paper thumbnail of 443 An immunotherapy trio in advanced HNSCC for coordinated B and T cell antigen response

Journal for ImmunoTherapy of Cancer, 2020

BackgroundOutcomes for recurrent or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC... more BackgroundOutcomes for recurrent or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) are dismal and responses to anti-PD-1 appear best in tumors with PD-1+ T cells in proximity to PD-L1+ cells, arguing that improved outcome is associated with a pre-existing anti-cancer immune response. Based on this, we hypothesize that vaccines which prime and/or expand T cells to a spectrum of antigens overexpressed by HNSCC combined with T cell agonists, like anti-GITR, that provide costimulatory signals will improve the anti-PD-1 response rates. We have developed a cancer vaccine, DPV-001, that contains more than 300 proteins for genes overexpressed by HNSCC, encapsulated in a CLEC9A-targeted microvesicle and containing TLR/NOD agonists and DAMPs. Recently, we reported that combining anti-GITR + vaccine + anti-PD-1 augmented therapeutic efficacy in a preclinical model and now plan a phase 1b trial of this combination in patients with advanced HNSCC.MethodsSera from patients receivi...

Research paper thumbnail of Abstract CT502: Preliminary immunological monitoring of first-in-human immunotherapy-trio for advanced head and neck squamous cell carcinoma

Cancer Research

Background: Preclinical studies document that complex cancer vaccines, combined with T cell agoni... more Background: Preclinical studies document that complex cancer vaccines, combined with T cell agonists and anti-PD-1, can augment therapeutic efficacy. Here we report preliminary immunological analyses of patients enrolled in a first-in-human immunotherapy-trio study of multivalent autophagosome vaccine (DPV-001), with sequenced checkpoint inhibition (anti-PD-1; retifanlimab), with/without anti-GITR agonist (INCAGN-1949), in recurrent or metastatic HNSCC (NCT04470024). Methods: Peripheral blood (PB) and sera are collected regularly and PB are evaluated by flow cytometry. Biopsies obtained at baseline, D15 and D45 are analyzed by multiplex IF and 10x Genomics scRNA-Seq. Sera are being analyzed by phage immunoprecipitation (PhIP) sequencing for reactivity against the human proteome. Results: Preliminary results document increases in activated CD4 and CD8 effector memory T cells (TEM) with vaccine alone. Changes in tumor microenvironment (TEM) were also observed with increased infiltrati...

Research paper thumbnail of Multispectral Fluorescence Imaging Allows for Distinctive Topographic Assessment and Subclassification of Tumor-Infiltrating and Surrounding Immune Cells

Methods in Molecular Biology

Histomorphology has significantly changed over the last decades due to technological achievements... more Histomorphology has significantly changed over the last decades due to technological achievements in immunohistochemistry (IHC) for the visualization of specific proteins and in molecular pathology, particularly in the field of in situ hybridization of small oligonucleotides and amplification of DNA and RNA amplicons. With an increased availability of suitable methods, the demands regarding the observer of histomorphological slides were the supply of complex quantitative data as well as more information about protein expression and cell-cell interactions in tissue sections. Advances in fluorescence-based multiplexed IHC techniques, such as multispectral imaging (MSI), allow the quantification of multiple proteins at the same tissue section. In histopathology, it is a well-known technique for over a decade yet harboring serious problems concerning quantitative preciseness and tissue autofluorescence of multicolor staining when using formalin-fixed, paraffin-embedded (FFPE) tissue specimen. In recent years, milestones in tissue preparation, fluorescent dyes, hardware imaging, and software analysis were achieved including automated tissue segmentation (e.g., tumor vs. stroma) as well as in cellular and subcellular multiparameter analysis.This chapter covers the role that MSI plays in anatomic pathology for the analysis of FFPE tissue sections, discusses the technical aspects of MSI, and provides a review of its application in the characterization of immune cell infiltrates and beyond regarding its prognostic and predictive value and its use for guidance of clinical decisions for immunotherapeutic strategies.

Research paper thumbnail of Open-source digital image analysis of whole-slide multiplex immunohistochemistry

Successful digital image analysis (DIA) of cancer tissue is accurate and reproducible. These poin... more Successful digital image analysis (DIA) of cancer tissue is accurate and reproducible. These points of emphasis have brought procedures like the tissue microarray (TMA) and hotspot regions of interest (ROI) under scrutiny. The nature in which a pathologist selects TMAs and ROIs is conducive to bias. Whole Slide Imaging (WSI) offers a solution in its unbiased region selection and consideration of a larger tissue sample. However, options for software that can handle such large throughput are scarce. Additionally, while multiplex immunohistochemistry (mIHC) is becoming popular (Feng et al.), documentation of its digital analysis tools remains minimal. The combination of these procedures potentiates a deeper understanding of the tumor microenvironment. This study presents the whole-slide mIHC analysis capabilities of QuPath, an open-source application developed at Queen's University Belfast . Methods. A multiplex fluorescent stain panel was performed on patient samples. The slides w...

Research paper thumbnail of In MCA-induced sarcoma models, booster vaccination with GM-CSF-secreting whole-cell tumor vaccines maintain or improve efficacy but may alter trafficking of tumor-specific T cells (VAC13P.1128)

Journal of Immunology, 2015

Previously, we reported that while a single vaccination effectively generated therapeutic tumor-s... more Previously, we reported that while a single vaccination effectively generated therapeutic tumor-specific T cells for adoptive immunotherapy (AIT), repeated vaccination with the poorly immunogenic B16BL6 melanoma, modified to secrete GM-CSF, induced high levels of CD4 + FoxP3 + T regulatory (T reg ) cells and AIT with spleen cells was non-therapeutic. The effect could be overcome by transient depletion of CD4 + T cells, confirming the effect of T reg cells. Here experiments were performed to test whether this suppressive effect was observed in active-specific protection in 2 sarcoma models, MCA-304 and MCA-310. Mice were vaccinated once or thrice with either irradiated parental sarcoma or that sarcoma expressing GM-CSF. We did not observe significant changes in percentage or total count of splenic T reg cells under any conditions, however, tumor-specific IFN-γ release decreased in mice thrice vaccinated with GM-CSF-secreting tumors compared to parental (p

Research paper thumbnail of Preliminary evaluation of a novel whole slide multispectral assessment of seven markers: Potential to minimize bias in the characterization of the tumor immune environment

PD-L1 expression and TMB enrich for patients that respond to checkpoint blockade, but these evalu... more PD-L1 expression and TMB enrich for patients that respond to checkpoint blockade, but these evaluations are only a component of the entire story. Recently, our lab reported that evaluation of specific cell-cell relationships provided a powerful biomarker for overall survival in patients with HPVhead and neck cancer (HNSCC). However, the areas selected for analysis were operator selected “hot spots”. This approach introduces the potential for unconscious bias in the selection process. To address this, we have sought to perform whole slide evaluations of sections to compare with hot spot analysis. This study is a preliminary report applying a novel set of fluorophores and filters that allow the visualization of seven colors on a whole slide. Tissue samples included pellets of cultured lymphocytes and tumor specimens. A sample of the cultured lymphocytes that were fixed and embedded were analyzed by flow cytometry for immune markers. Formalin-fixed paraffin embedded (FFPE) sections wer...

Research paper thumbnail of Novel strategy increases capacity of tumor vaccine to provide cross-protection against unique MCA-induced sarcomas

Cancer Research, 2008

AACR Annual Meeting-- Apr 12-16, 2008; San Diego, CA 2847 Vaccination with irradiated 3-Methylcho... more AACR Annual Meeting-- Apr 12-16, 2008; San Diego, CA 2847 Vaccination with irradiated 3-Methylcholanthrene (MCA)-induced tumor cells provides protection from a subsequent viable challenge with the same MCA tumor, but not other MCA-induced tumors. This observation of unique tumor-specific protection, first reported in 1957 by Prehn and Main, has been well documented by numerous laboratories, including ours and is a well-established paradigm in tumor immunology. We postulated that all MCA-induced sarcomas overexpress some genes in common, but only the unique tumor-rejection antigens are stable enough to be cross-presented and induce antitumor immunity. We further postulated that the overexpressed genes common to most/all sarcomas are proteins with a very short half-life, such as Defective Ribosomal Proteins (DRiPs) and Short-Lived Proteins (SLiPS), which are not cross-presented due to their transient nature. Recently we (H. Hu, manuscript submitted) developed a strategy where DRiPs an...

Research paper thumbnail of Phosphorylation of SMAD3 in immune cells predicts survival of patients with early stage non-small cell lung cancer

Journal for ImmunoTherapy of Cancer, 2021

BackgroundThe interplay of immune and cancer cells takes place in the tumor microenvironment wher... more BackgroundThe interplay of immune and cancer cells takes place in the tumor microenvironment where multiple signals are exchanged. The transforming growth factor beta (TGFB) pathway is known to be dysregulated in lung cancer and can impede an effective immune response. However, the exact mechanisms are yet to be determined. Especially which cells respond and where does this signaling take place with respect to the local microenvironment.MethodsHuman non-small cell lung cancer samples were retrospectively analyzed by multiplexed immunohistochemistry for SMAD3 phosphorylation and programmed death ligand 1 expression in different immune cells with respect to their localization within the tumor tissue. Spatial relationships were studied to examine possible cell-cell interactions and analyzed in conjunction with clinical data.ResultsTGFB pathway activation in CD3, CD8, Foxp3 and CD68 cells, as indicated by SMAD3 phosphorylation, negatively impacts overall and partially disease-free survi...

Research paper thumbnail of 383 Durable responses with intratumoral electroporation of plasmid interleukin 12 plus pembrolizumab in patients with advanced melanoma progressing on an anti-PD-1 antibody: updated data from keynote 695

Journal for ImmunoTherapy of Cancer, 2021

BackgroundElectroporated plasmid interleukin-12 (pIL-12-EP; tavokinogene telseplasmid; TAVO) indu... more BackgroundElectroporated plasmid interleukin-12 (pIL-12-EP; tavokinogene telseplasmid; TAVO) induces sustained intratumoral expression of IL-12, a cytokine that is integral for response to anti-PD-1 antibodies. Here, we present updated safety and response duration data from KEYNOTE 695, a Phase 2, multicenter, open-label trial of pIL-12-EP in combination with pembrolizumab in patients with stage III/IV melanoma immediately following confirmed progression on an anti-PD-1 antibody.MethodsPatients with confirmed disease progression after ≥12 weeks‘ treatment with an anti-PD-1 antibody alone or in combination were eligible. Patients received intratumoral pIL-12-EP on days 1, 5 and 8 every 6 weeks and pembrolizumab 200 mg every 3 weeks. Responses were assessed by the investigator at 12-week intervals using RECIST v1.1; overall survival (OS) and duration of response (DoR) assessments were conducted using the Kaplan-Meier method.ResultsOf the first 56 patients treated, 50% had visceral dis...

Research paper thumbnail of Intratumoral Plasmid IL12 Expands CD8+ T Cells and Induces a CXCR3 Gene Signature in Triple-negative Breast Tumors that Sensitizes Patients to Anti–PD-1 Therapy

Clinical Cancer Research, 2021

Purpose: Triple-negative breast cancer (TNBC) is an aggressive disease with limited therapeutic o... more Purpose: Triple-negative breast cancer (TNBC) is an aggressive disease with limited therapeutic options. Antibodies targeting programmed cell death protein 1 (PD-1)/PD-1 ligand 1 (PD-L1) have entered the therapeutic landscape in TNBC, but only a minority of patients benefit. A way to reliably enhance immunogenicity, T-cell infiltration, and predict responsiveness is critically needed. Patients and Methods: Using mouse models of TNBC, we evaluate immune activation and tumor targeting of intratumoral IL12 plasmid followed by electroporation (tavokinogene telseplasmid; Tavo). We further present a single-arm, prospective clinical trial of Tavo monotherapy in patients with treatment refractory, advanced TNBC (OMS-I140). Finally, we expand these findings using publicly available breast cancer and melanoma datasets. Results: Single-cell RNA sequencing of murine tumors identified a CXCR3 gene signature (CXCR3-GS) following Tavo treatment associated with enhanced antigen presentation, T-cell...

Research paper thumbnail of Multi-institutional TSA-amplified Multiplexed Immunofluorescence Reproducibility Evaluation (MITRE) Study

Journal for ImmunoTherapy of Cancer, 2021

BackgroundEmerging data suggest predictive biomarkers based on the spatial arrangement of cells o... more BackgroundEmerging data suggest predictive biomarkers based on the spatial arrangement of cells or coexpression patterns in tissue sections will play an important role in precision immuno-oncology. Multiplexed immunofluorescence (mIF) is ideally suited to such assessments. Standardization and validation of an end-to-end workflow that supports multisite trials and clinical laboratory processes are vital. Six institutions collaborated to: (1) optimize an automated six-plex assay focused on the PD-1/PD-L1 axis, (2) assess intersite and intrasite reproducibility of staining using a locked down image analysis algorithm to measure tumor cell and immune cell (IC) subset densities, %PD-L1 expression on tumor cells (TCs) and ICs, and PD-1/PD-L1 proximity assessments.MethodsA six-plex mIF panel (PD-L1, PD-1, CD8, CD68, FOXP3, and CK) was rigorously optimized as determined by quantitative equivalence to immunohistochemistry (IHC) chromogenic assays. Serial sections from tonsil and breast carci...

Research paper thumbnail of 480 Preliminary evaluation of a novel coronavirus vaccine (CORVax) using electroporation of plasmid DNA encoding a stabilized prefusion SARS-CoV-2 spike protein alone or with transfection of plasmid IL-12

Regular and young investigator award abstracts, 2020

BackgroundSARS-CoV-2 (CoV2) has precipitated a global pandemic and the effectiveness of standard ... more BackgroundSARS-CoV-2 (CoV2) has precipitated a global pandemic and the effectiveness of standard vaccine strategies to induce potent and persistent immunity to CoV2 is in question, particularly for the elderly. This problem is not dissimilar to what we have struggled with in our quest to induce immunity to cancer antigens, where vaccine-induced anti-cancer immune responses can be weak. Here, we describe a novel vaccine approach which leverages electroporation (EP) of a plasmid encoding a prefusion stabilized CoV2 spike protein (CORVax). As IL-12 has been shown to augment the efficacy of immunotherapy in aged mice,1 we have initiated studies to evaluate if plasmid IL-12 (TAVO™) can similarly augment anti-CoV2 immune responses in young mice and have planned studies in aged animals.MethodsA prefusion stabilized CoV2 spike plasmid expression vector was constructed, a master cell bank generated and clinical-grade plasmid manufactured. C57BL/6 and BALB/c were vaccinated via intramuscular ...

Research paper thumbnail of SARS-CoV-2 antibodies detected in human breast milk post-vaccination

ABSTRACTImportanceThe SARS-CoV-2 pandemic has infected over a hundred million people worldwide, w... more ABSTRACTImportanceThe SARS-CoV-2 pandemic has infected over a hundred million people worldwide, with almost 2.5 million deaths at the date of this publication. In the United States, Pfizer-BioNTech and Moderna vaccines were first administered to the public starting in December 2020, and no lactating women were included in the initial trials of safety/efficacy. Research on SARS-CoV-2 vaccination in lactating women and the potential transmission of passive immunity to the infant through breast milk is needed to guide patients, clinicians and policy makers during the worldwide effort to curb the spread of this virus.ObjectiveTo determine whether SARS-CoV-2 specific immunoglobins are found in breast milk post-vaccination, and to characterize the time course and types of immunoglobulins present.DesignProspective cohort studySettingProvidence Portland Medical Center, Oregon, USAParticipantsSix lactating women who planned to receive both doses of the Pfizer-BioNTech or Moderna vaccine betw...

Research paper thumbnail of 799 Durable responses and immune activation with intratumoral electroporation of pIL-12 plus pembrolizumab in actively progressing anti-PD-1 refractory advanced melanoma: KEYNOTE 695 interim data

Late-breaking abstracts, 2020

BackgroundElectroporated plasmid IL-12 (TAVO or tavokinogene telseplasmid) is a novel pro-inflamm... more BackgroundElectroporated plasmid IL-12 (TAVO or tavokinogene telseplasmid) is a novel pro-inflammatory intratumoral therapy with substantial single agent activity in melanoma, which has been shown to synergize with anti-PD-1 antibodies in patients predicted as non-responders to anti-PD-1.1 2 Interim data from patients with stage III/IV melanoma actively progressing on anti-PD-1 antibody are presented herein.MethodsPatients with confirmed disease progression by RECIST v1.1 after at least 12 weeks of treatment on pembrolizumab or nivolumab (or combination checkpoint blockade) and within 12 weeks of last dose (with no intervening therapies) were enrolled. There was no limit on the number of prior lines of therapy. At least one accessible lesion was electroporated with plasmid IL-12 (pIL-12-EP) on days 1, 5 and 8 every 6 weeks and pembrolizumab was administered every 3 weeks. Tumor response in treated and untreated lesions was assessed by RECIST v1.1 every 12 weeks. Endpoints include OR...

Research paper thumbnail of Heterodimeric IL-15 delays tumor growth and promotes intratumoral CTL and dendritic cell accumulation by a cytokine network involving XCL1, IFN-γ, CXCL9 and CXCL10

Journal for ImmunoTherapy of Cancer, 2020

BackgroundInterleukin-15 (IL-15) promotes growth and activation of cytotoxic CD8+T and natural ki... more BackgroundInterleukin-15 (IL-15) promotes growth and activation of cytotoxic CD8+T and natural killer (NK) cells. Bioactive IL-15 is produced in the body as a heterodimeric cytokine, comprising the IL-15 and IL-15 receptor alpha chains (hetIL-15). Several preclinical models support the antitumor activity of hetIL-15 promoting its application in clinical trials.MethodsThe antitumor activity of hetIL-15 produced from mammalian cells was tested in mouse tumor models (MC38 colon carcinoma and TC-1 epithelial carcinoma). The functional diversity of the immune infiltrate and the cytokine/chemokine network within the tumor was evaluated by flow cytometry, multicolor immunohistochemistry (IHC), gene expression profiling by Nanostring Technologies, and protein analysis by electrochemiluminescence and ELISA assays.ResultshetIL-15 treatment resulted in delayed primary tumor growth. Increased NK and CD8+T cell tumoral infiltration with an increased CD8+/Treg ratio were found by flow cytometry a...

Research paper thumbnail of Effect of various decontamination procedures on disposable N95 mask integrity and SARS-CoV-2 infectivity

The COVID-19 pandemic has created a high demand on personal protective equipment, including dispo... more The COVID-19 pandemic has created a high demand on personal protective equipment, including disposable N95 masks. Given the need for mask reuse, we tested the feasibility of vaporized hydrogen peroxide (VHP), ultraviolet light (UV), and ethanol decontamination strategies on N95 mask integrity and the ability to remove the infectious potential of SARS-CoV-2. FIT test data showed functional degradation by both ethanol and UV decontamination to different degrees. VHP treated masks showed no significant change in function after two treatments. We also report a single SARS-CoV-2 virucidal experiment using Vero E6 cell infection. We hope our data will guide further research for evidenced-based decisions for disposable N95 mask reuse and help protect caregivers from SARS-CoV-2 and other pathogens.

Research paper thumbnail of Abstract LB-318: Multi-institutional TSA-amplified Multiplexed Immunofluorescence Reproducibility Evaluation (MITRE study): Reproducibility assessment of an automated multiplexed immunofluorescence slide staining, imaging, and analysis workflow

Tumor Biology, 2019

Background: Emerging data suggests that predictive biomarkers based on the spatial arrangement of... more Background: Emerging data suggests that predictive biomarkers based on the spatial arrangement of multiple cell types in FFPE tissue sections will be an important component of precision medicine in immune-oncology. Multiplexed immunofluorescence (mIF) facilitates such assessments. If mIF is to play a translational role in research and ultimately clinical practice, it is vital to refine, standardize, and validate an end-to-end workflow that supports large scale multi-site trials and clinical laboratory processes. To this end, six institutions collaborated to develop an automated 6-plex assay focused on the PD-1/PD-L1 axis and assessed its inter- and intra-site reproducibility. Specific attention was paid to assessment of %PD-L1 expression by immune cells (ICs), as pathologists have poor concordance for this parameter as noted in the Blueprint 2 and multi-institutional NCCN studies on PD-L1 IHC. Methods: A 7-color mIF panel (PD-L1, PD-1, CD8, CD68, FoxP3, Cytokeratin, and DAPI) was optimized on a Leica Bond Rx autostainer. Serial sections of tonsil and a lung cancer tissue-microarray (TMA), antibodies and TSA-Opal detection reagents (Akoya Biosciences) were distributed. Cell pellet arrays were also distributed and used to normalize batch variation in intensity measurements. Tonsil and TMA sections were stained at each site and imaged at 20x using a Vectra Polaris. Cells were segmented and phenotyped using image analysis algorithms. In tonsil sections, the average intensity of the top quartile of cells positive for each marker was assessed to identify potential variation in staining intensity. In lung TMAs, cell densities and %PD-L1 expression in immune cells (CD68+ and CD8+ cells) was determined. Results: The average staining intensity coefficients of variation (CV) for all markers within sites was 10% in tonsil samples. Inter-site concordance for tumor cell and immune cell subset densities in TMAs, had an average R2 value of 0.86 and slope of 0.96. Inter-site concordance for %PD-L1+ ICs had an average R2 value of 0.81, and slope of 0.82, in contrast to ICC values of Conclusions: We demonstrate a reproducible end-to-end process for mIF characterization of the PD-1/PD-L1 axis including automated staining, multispectral imaging, and machine-learning-trained image analysis algorithms. This approach improved reproducibility of %PD-L1 IC assessment and brought it in line with %PD-L1 tumor cell assessment by pathologists. Sources of variation were identified and will be discussed. The described approach may serve as a template for assessing reproducibility of emerging mIF panels for other investigative teams, with an eye toward translating such approaches into clinical trials and ultimately into the clinic. Citation Format: Clifford Hoyt, Kristin Roman, Liz Engle, Chichung Wang, Carmen Ballesteros-Merino, Shawn M. Jensen, John McGuire, Yi Zheng, Carla Coltharp, Mei Jiang, Justin Lucas, Edwin Parra, Ignacio Wistuba, Darren Locke, Bernard A. Fox, David L. Rimm, Janis Marie Taube. Multi-institutional TSA-amplified Multiplexed Immunofluorescence Reproducibility Evaluation (MITRE study): Reproducibility assessment of an automated multiplexed immunofluorescence slide staining, imaging, and analysis workflow [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-318.

Research paper thumbnail of Abstract LB-088: Heterodimeric IL-15 enhances tumor infiltration, persistence and effector functions of adoptively transferred tumor-specific T cells in the absence of lymphodepletion

Cancer Research, 2016

Adoptive cell transfer (ACT) is a promising immunotherapeutic approach for cancer. Lymphodepletio... more Adoptive cell transfer (ACT) is a promising immunotherapeutic approach for cancer. Lymphodepletion of the host is associated with favorable ACT outcomes but it may cause detrimental effects in humans. Lymphodepletion results in high level of homeostatic cytokines including Interleukin-15 (IL-15) that support survival and proliferation of the transferred lymphocytes. We tested the hypothesis that exogenous IL-15 enhances ACT in the absence of lymphodepletion. We have previously shown that bioactive IL-15 in vivo comprises a stable complex of the IL-15 chain with the IL-15 Receptor alpha chain, termed heterodimeric IL-15 (hetIL-15). We therefore evaluated the effects of the combination regimen ACT+hetIL-15 in absence of lymphodepletion by transferring melanoma-specific Pmel-1 T cells into B16 melanoma-bearing mice. hetIL-15 promoted infiltration and persistence of both adoptively transferred Pmel-1 cells and endogenous CD8+ T cells in the tumor. Following lymphodepletion by irradiatio...