Showing papers by "Lisa M. Coussens published in 2019"

Chemotherapy elicits pro-metastatic extracellular vesicles in breast cancer models

Abstract: Cytotoxic chemotherapy is an effective treatment for invasive breast cancer. However, experimental studies in mice also suggest that chemotherapy has pro-metastatic effects. Primary tumours release extracellular vesicles (EVs), including exosomes, that can facilitate the seeding and growth of metastatic cancer cells in distant organs, but the effects of chemotherapy on tumour-derived EVs remain unclear. Here we show that two classes of cytotoxic drugs broadly employed in pre-operative (neoadjuvant) breast cancer therapy, taxanes and anthracyclines, elicit tumour-derived EVs with enhanced pro-metastatic capacity. Chemotherapy-elicited EVs are enriched in annexin A6 (ANXA6), a Ca2+-dependent protein that promotes NF-κB-dependent endothelial cell activation, Ccl2 induction and Ly6C+CCR2+ monocyte expansion in the pulmonary pre-metastatic niche to facilitate the establishment of lung metastasis. Genetic inactivation of Anxa6 in cancer cells or Ccr2 in host cells blunts the pro-metastatic effects of chemotherapy-elicited EVs. ANXA6 is detected, and potentially enriched, in the circulating EVs of breast cancer patients undergoing neoadjuvant chemotherapy.

Reprogramming the Tumor Microenvironment to Improve Immunotherapy: Emerging Strategies and Combination Therapies

Abstract: Emerging immunotherapeutic approaches have revolutionized the treatment of multiple malignancies. Immune checkpoint blockers (ICBs) have enabled never-before-seen success rates in durable tumor control and enhanced survival benefit in patients with advanced cancers. However, this effect is not universal, resulting in responder and nonresponder populations not only between, but also within solid tumor types. Although ICBs are thought to be most effective against tumors with more genetic mutations and higher antigen loads, this is not always the case for all cancers or for all patients within a cancer subtype. Furthermore, debilitating and sometimes deadly immune-related adverse events (irAEs) have resulted from aberrant activation of T-cell responses following immunotherapy. Thus, we must identify new ways to overcome resistance to ICB-based immunotherapies and limit irAEs. In fact, preclinical and clinical data have identified abnormalities in the tumor microenvironment (TME) that can thwart the efficacy of immunotherapies such as ICBs. Here, we will discuss how reprogramming various facets of the TME (blood vessels, myeloid cells, and regulatory T cells [Tregs]) may overcome TME-instigated resistance mechanisms to immunotherapy. We will discuss clinical applications of this strategic approach, including the recent successful phase III trial combining bevacizumab with atezolizumab and chemotherapy for metastatic nonsquamous non-small cell lung cancer that led to rapid approval by the U.S. Food and Drug Administration of this regimen for first-line treatment. Given the accelerated testing and approval of ICBs combined with various targeted therapies in larger numbers of patients with cancer, we will discuss how these concepts and approaches can be incorporated into clinical practice to improve immunotherapy outcomes.

The TLR7/8 agonist R848 remodels tumor and host responses to promote survival in pancreatic cancer

Abstract: A priority in cancer research is to innovate therapies that are not only effective against tumor progression but also address comorbidities such as cachexia that limit quality and quantity of life. We demonstrate that TLR7/8 agonist R848 induces anti-tumor responses and attenuates cachexia in murine models of pancreatic ductal adenocarcinoma (PDAC). In vivo, tumors from two of three cell lines were R848-sensitive, resulting in smaller tumor mass, increased immune complexity, increased CD8+ T-cell infiltration and activity, and decreased Treg frequency. R848-treated mice demonstrated improvements in behavioral and molecular cachexia manifestations, resulting in a near-doubling of survival duration. Knockout mouse studies revealed that stromal, not neoplastic, TLR7 is requisite for R848-mediated responses. In patient samples, we found Tlr7 is ubiquitously expressed in stroma across all stages of pancreatic neoplasia, but epithelial Tlr7 expression is relatively uncommon. These studies indicate immune-enhancing approaches including R848 may be useful in PDAC and cancer-associated cachexia. In the treatment of pancreatic ductal adenocarcinoma (PDAC), comorbidities such as cachexia limit quality of life and survival. Here, the authors show TLR7/8 agonist R848 remodels host and tumour immune responses, promoting survival and attenuating cachexia in murine models of PDAC.

Phase Ib study of the combination of pexidartinib (PLX3397), a CSF-1R inhibitor, and paclitaxel in patients with advanced solid tumors:

Abstract: Purpose:To evaluate the safety, recommended phase II dose (RP2D) and efficacy of pexidartinib, a colony stimulating factor receptor 1 (CSF-1R) inhibitor, in combination with weekly paclitaxel in pa...

Poor response to neoadjuvant chemotherapy correlates with mast cell infiltration in inflammatory breast cancer

Abstract: Our understanding is limited concerning the tumor immune microenvironment of inflammatory breast cancer (IBC), an aggressive form of primary cancer with low rates of pathologic complete response to current neoadjuvant chemotherapy (NAC) regimens. We retrospectively identified pretreatment (N = 86) and matched posttreatment tissue (N = 27) from patients with stage III or de novo stage IV IBC who received NAC followed by a mastectomy. Immune profiling was performed including quantification of lymphoid and myeloid infiltrates by IHC and T-cell repertoire analysis. Thirty-four of 86 cases in this cohort (39.5%) achieved a pathologic complete response. Characterization of the tumor microenvironment revealed that having a lower pretreatment mast cell density was significantly associated with achieving a pathologic complete response to NAC (P = 0.004), with responders also having more stromal tumor-infiltrating lymphocytes (P = 0.035), CD8+ T cells (P = 0.047), and CD20+ B cells (P = 0.054). Spatial analysis showed close proximity of mast cells to CD8+ T cells, CD163+ monocytes/macrophages, and tumor cells when pathologic complete response was not achieved. PD-L1 positivity on tumor cells was found in fewer than 2% of cases and on immune cells in 27% of cases, but with no correlation to response. Our results highlight the strong association of mast cell infiltration with poor response to NAC, suggesting a mechanism of treatment resistance and a potential therapeutic target in IBC. Proximity of mast cells to immune and tumor cells may suggest immunosuppressive or tumor-promoting interactions of these mast cells.

Clinical Response of Live-Attenuated, Listeria monocytogenes Expressing Mesothelin (CRS-207) with Chemotherapy in Patients with Malignant Pleural Mesothelioma.

Abstract: Purpose: Malignant pleural mesothelioma (MPM) is an aggressive cancer associated with poor prognosis. CRS-207 is a live-attenuated Listeria monocytogenes engineered to express mesothelin, a tumor-associated antigen highly expressed in MPM. CRS-207 induces antitumor immune responses and increases susceptibility of neoplastic cells to immune-mediated killing. Patients and Methods: Patients with unresectable MPM, ECOG 0 or 1, and adequate organ and pulmonary function were enrolled in this multicenter, open-label phase Ib study. They received two priming infusions of 1 × 109 CFU CRS-207, followed by pemetrexed/cisplatin chemotherapy, and CRS-207 booster infusions. Primary objectives were safety and induction of immune response. Secondary/exploratory objectives included tumor response, progression-free survival (PFS), overall survival (OS), immune subset analysis, and gene-expression profiling of tumor. Results: Of 35 evaluable patients, 89% (31/35) had disease control with one complete response (3%), 19 partial responses (54%), and 10 stable disease (29%). The estimated median duration of response was 5.0 months (95% CI, 3.9–11.5). The median PFS and OS were 7.5 (95% CI, 7.0–9.9) and 14.7 (95% CI, 11.2–21.9) months, respectively. Tumor size reduction was observed post–CRS-207 infusion prior to chemotherapy in 11 of 35 (31%) patients. No unexpected treatment-related serious adverse events or deaths were observed. IHC analysis of pre- and post–CRS-207 treatment tumor biopsies revealed possible reinvigoration and proliferation of T cells, increased infiltration of dendritic and natural killer cells, increased CD8:Treg ratio, and a shift from immunosuppressive M2-like to proinflammatory M1-like macrophages following CRS-207 administration. Conclusions: Combination of CRS-207 and chemotherapy induced significant changes in the local tumor microenvironment and objective tumor responses in a majority of treated patients.

Dissecting the Stromal Signaling and Regulation of Myeloid Cells and Memory Effector T Cells in Pancreatic Cancer

Abstract: Purpose: Myeloid cells are a prominent immunosuppressive component within the stroma of pancreatic ductal adenocarcinoma (PDAC). Previously, targeting myeloid cells has had limited success. Here, we sought to target the myeloid cells through modifying a specific stromal component. Experimental Design: A murine model of metastatic PDAC treated with an irradiated whole-cell PDAC vaccine and PDAC specimens from patients treated with the same type of vaccine were used to assess the immune-modulating effect of stromal hyaluronan (HA) degradation by PEGPH20. Results: Targeting stroma by degrading HA with PEGPH20 in combination with vaccine decreases CXCL12/CXCR4/CCR7 immunosuppressive signaling axis expression in cancer-associated fibroblasts, myeloid, and CD8+ T cells, respectively. This corresponds with increased CCR7− effector memory T-cell infiltration, an increase in tumor-specific IFNγ, and improved survival. In the stroma of human PDACs treated with the same vaccine, decreased stromal CXCR4 expression significantly correlated with decreased HA and increased cytotoxic activities, suggesting CXCR4 is an important therapeutic target. Conclusions: This study represents the first to dissect signaling cascades following PDAC stroma remodeling via HA depletion, suggesting this not only overcomes a physical barrier for immune cell trafficking, but alters myeloid function leading to downstream selective increases in effector memory T-cell infiltration and antitumor activity.

Toward a comprehensive view of cancer immune responsiveness: A synopsis from the SITC workshop

Abstract: Tumor immunology has changed the landscape of cancer treatment. Yet, not all patients benefit as cancer immune responsiveness (CIR) remains a limitation in a considerable proportion of cases. The multifactorial determinants of CIR include the genetic makeup of the patient, the genomic instability central to cancer development, the evolutionary emergence of cancer phenotypes under the influence of immune editing, and external modifiers such as demographics, environment, treatment potency, co-morbidities and cancer-independent alterations including immune homeostasis and polymorphisms in the major and minor histocompatibility molecules, cytokines, and chemokines. Based on the premise that cancer is fundamentally a disorder of the genes arising within a cell biologic process, whose deviations from normality determine the rules of engagement with the host’s response, the Society for Immunotherapy of Cancer (SITC) convened a task force of experts from various disciplines including, immunology, oncology, biophysics, structural biology, molecular and cellular biology, genetics, and bioinformatics to address the complexity of CIR from a holistic view. The task force was launched by a workshop held in San Francisco on May 14–15, 2018 aimed at two preeminent goals: 1) to identify the fundamental questions related to CIR and 2) to create an interactive community of experts that could guide scientific and research priorities by forming a logical progression supported by multiple perspectives to uncover mechanisms of CIR. This workshop was a first step toward a second meeting where the focus would be to address the actionability of some of the questions identified by working groups. In this event, five working groups aimed at defining a path to test hypotheses according to their relevance to human cancer and identifying experimental models closest to human biology, which include: 1) Germline-Genetic, 2) Somatic-Genetic and 3) Genomic-Transcriptional contributions to CIR, 4) Determinant(s) of Immunogenic Cell Death that modulate CIR, and 5) Experimental Models that best represent CIR and its conversion to an immune responsive state. This manuscript summarizes the contributions from each group and should be considered as a first milestone in the path toward a more contemporary understanding of CIR. We appreciate that this effort is far from comprehensive and that other relevant aspects related to CIR such as the microbiome, the individual’s recombined T cell and B cell receptors, and the metabolic status of cancer and immune cells were not fully included. These and other important factors will be included in future activities of the taskforce. The taskforce will focus on prioritization and specific actionable approach to answer the identified questions and implementing the collaborations in the follow-up workshop, which will be held in Houston on September 4–5, 2019.

Innate αβ T cells Mediate Antitumor Immunity by Orchestrating Immunogenic Macrophage Programming

Abstract: Unconventional T-lymphocyte populations are emerging as important regulators of tumor immunity. Despite this, the role of TCRαβ+CD4-CD8-NK1.1- innate αβ T cells (iαβT) in pancreatic ductal adenocarcinoma (PDA) has not been explored. We found that iαβTs represent ∼10% of T lymphocytes infiltrating PDA in mice and humans. Intratumoral iαβTs express a distinct T-cell receptor repertoire and profoundly immunogenic phenotype compared with their peripheral counterparts and conventional lymphocytes. iαβTs comprised ∼75% of the total intratumoral IL17+ cells. Moreover, iαβT-cell adoptive transfer is protective in both murine models of PDA and human organotypic systems. We show that iαβT cells induce a CCR5-dependent immunogenic macrophage reprogramming, thereby enabling marked CD4+ and CD8+ T-cell expansion/activation and tumor protection. Collectively, iαβTs govern fundamental intratumoral cross-talk between innate and adaptive immune populations and are attractive therapeutic targets. SIGNIFICANCE: We found that iαβTs are a profoundly activated T-cell subset in PDA that slow tumor growth in murine and human models of disease. iαβTs induce a CCR5-dependent immunogenic tumor-associated macrophage program, T-cell activation and expansion, and should be considered as novel targets for immunotherapy.See related commentary by Banerjee et al., p. 1164.This article is highlighted in the In This Issue feature, p. 1143.

Robust Cell Detection and Segmentation for Image Cytometry Reveal Th17 Cell Heterogeneity.

Abstract: Image cytometry enables quantitative cell characterization with preserved tissue architecture; thus, it has been highlighted in the advancement of multiplex immunohistochemistry (IHC) and digital image analysis in the context of immune-based biomarker monitoring associated with cancer immunotherapy. However, one of the challenges in the current image cytometry methodology is a technical limitation in the segmentation of nuclei and cellular components particularly in heterogeneously stained cancer tissue images. To improve the detection and specificity of single-cell segmentation in hematoxylin-stained images (which can be utilized for recently reported 12-biomarker chromogenic sequential multiplex IHC), we adapted a segmentation algorithm previously developed for hematoxlin and eosin-stained images, where morphological features are extracted based on Gabor-filtering, followed by stacking of image pixels into n-dimensional feature space and unsupervised clustering of individual pixels. Our proposed method showed improved sensitivity and specificity in comparison with standard segmentation methods. Replacing previously proposed methods with our method in multiplex IHC/image cytometry analysis, we observed higher detection of cell lineages including relatively rare TH 17 cells, further enabling sub-population analysis into TH 1-like and TH 2-like phenotypes based on T-bet and GATA3 expression. Interestingly, predominance of TH 2-like TH 17 cells was associated with human papilloma virus (HPV)-negative status of oropharyngeal squamous cell carcinoma of head and neck, known as a poor-prognostic subtype in comparison with HPV-positive status. Furthermore, TH 2-like TH 17 cells in HPV-negative head and neck cancer tissues were spatiotemporally correlated with CD66b+ granulocytes, presumably associated with an immunosuppressive microenvironment. Our cell segmentation method for multiplex IHC/image cytometry potentially contributes to in-depth immune profiling and spatial association, leading to further tissue-based biomarker exploration. © 2019 International Society for Advancement of Cytometry.

Tumor immune microenvironment characteristics of papillary thyroid carcinoma are associated with histopathological aggressiveness and BRAF mutation status

Abstract: Background Papillary thyroid carcinoma (PTC) follows an indolent course; however, up to 30% of patients develop recurrent disease requiring further treatment. Profiling PTC immune complexity may provide new biomarkers for improved risk prediction. Methods Immune complexity profiles were quantitatively evaluated by multiplex immunohistochemistry (mIHC) in archived tissue sections from 39 patients with PTC, and were assessed for correlations with aggressive histopathological features based on the presence of lymphovascular invasion and/or extrathyroidal extension, and BRAF V600E mutational status. Results mIHC revealed two distinct immune clusters stratifying patients: a lymphoid-inflamed group (higher CD8+ T cells, reduced dendritic and mast cells) and a myeloid/hypo-inflamed group that correlated with aggressive pathological features. BRAF mutation was not associated with aggressive pathological features but did correlate with increased mast cell density. Conclusions Distinct immune microenvironments exist in PTC correlating with pathological aggressiveness. Immune-based biomarkers associated with possible tumor-immune interactions may be used for risk stratification.

Publisher Correction: The TLR7/8 agonist R848 remodels tumor and host responses to promote survival in pancreatic cancer

Abstract: An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Correction to: Toward a comprehensive view of cancer immune responsiveness: a synopsis from the SITC workshop

Abstract: Following publication of the original article [1], the author reported that an author name, Roberta Zappasodi, was missed in the authorship list.

Abstract 1558: Therapeutic targeting of cell surface plectin induces anti-cancer immune response and pancreatic cancer regression

Abstract: Background: Pancreatic ductal adenocarcinoma (PDA) is the 3rd deadliest cancer, diagnosed typically in advanced stages, with only an 8% 5-year survival rate, thus demonstrating the need for novel therapeutic approaches that significantly enhance chemo- and/or immune-therapy. Our team previously identified a promising functional target for cancer therapy in PDA, cell surface plectin 1 (CSP1) that is aberrantly expressed on PDA cells and thus a cell surface-associated biomarker of cancer. CSP1 expression first becomes apparent in high grade dysplasias, remaining high in early and advanced cancers and in metastases. Our first-in-human imaging trial in PDA patients using a CSP1-targeted imaging agent revealed that CSP is an available target and accessible for binding, a potentially a target for cancer therapy. We hypothesized that a monoclonal antibody (mAb) against CSP1 could lead to novel pancreatic cancer treatment options, thus, we developed a therapeutic mAb, e.g., ZB131, representing a first-in-class antibody selectively targeting CSP1. Methods: ZB131 is a humanized mAb targeted against human plectin 1 (rhSec8) that also binds murine CSP1. ZB131 affinity and its effect on cancer cells including proliferation, cytotoxicity, and migration were tested in vitro using saturation binding, SRB-based survival assays, flow cytometry, and migration assays on various pancreatic cell types and homeostatic “normal” controls. In vivo validation was performed using two nu/nu mouse models bearing subcutaneous MiaPACA2 or Yapc PDA cells, and a syngeneic KPC-derived tumor model to also evaluate immune responses to tumors treated with ZB131 or IgG control. Results: ZB131 exhibits high specificity and high affinity (0.4±0.1nM) to CSP1, and functionally induces G0 growth arrest followed by necrotic cell death of PDA cells in culture, and is synergistic with gemcitabine resulting in a 50-fold decrease in IC50. In vivo, in subcutaneous xenograft models, ZB131 monotherapy decreased PDA tumor volume 5-fold as compared to controls, and in combination with cisplatin resulted in sustained tumor reduction with greater than 85% tumor necrosis. In subcutaneous syngeneic PDA models, ZB131 induced complete tumor regression within 35 days mediated by an anti-tumor immune response as upon tumor rechallenge, full tumor regression was again achieved without additional ZB131 therapy. Leukocyte complexity analysis of regressing PDA tumors versus controls revealed an ~3-fold increase in effector and central memory T cells. Conclusion: CSP1 is a first in class anti-cancer target expressed on the cell surface of PDA, as well as other cancers including ovarian, esophageal and head neck. ZB131, an anti-CSP1 mAb, induces tumor cell intrinsic cell death, as well as a robust anti-tumor T cell response leading to complete tumor regression indicating the potential therapeutic efficacy of ZB131 in late-stage cancers. Citation Format: Julien Dimastromatteo, Amanda Poisonnier, Samantha Perez, Lisa Coussens, Kimberly Kelly. Therapeutic targeting of cell surface plectin induces anti-cancer immune response and pancreatic cancer regression [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 1558.