Plasticity-induced repression of Irf6 underlies acquired resistance to cancer immunotherapy in pancreatic ductal adenocarcinoma.

Acquired resistance to immunotherapy remains a critical yet incompletely understood biological mechanism. Here, using a mouse model of pancreatic ductal adenocarcinoma (PDAC) to study tumor relapse following immunotherapy-induced responses, we find that resistance is reproducibly associated with an epithelial-to-mesenchymal transition (EMT), with EMT-transcription factors ZEB1 and SNAIL functioning as master genetic and epigenetic regulators of this effect. Acquired resistance in this model is not due to immunosuppression in the tumor immune microenvironment, disruptions in the antigen presentation machinery, or altered expression of immune checkpoints. Rather, resistance is due to a tumor cell-intrinsic defect in T-cell killing. Molecularly, EMT leads to the epigenetic and transcriptional silencing of interferon regulatory factor 6 (Irf6), rendering tumor cells less sensitive to the pro-apoptotic effects of TNF-α. These findings indicate that acquired resistance to immunotherapy may be mediated by programs distinct from those governing primary resistance, including plasticity programs that render tumor cells impervious to T-cell killing.

Plasticity-induced repression of Irf6 underlies acquired resistance to cancer immunotherapy.

Acquired resistance to immune checkpoint immunotherapy remains a critical yet incompletely understood biological mechanism. Here, using a mouse model of pancreatic ductal adenocarcinoma (PDAC) to study tumor relapse following immunotherapy-induced responses, we found that tumors underwent an epithelial-to-mesenchymal transition (EMT) that resulted in reduced sensitivity to T cell-mediated killing. EMT-transcription factors (EMT-TFs) ZEB1 and SNAIL function as master genetic and epigenetic regulators of this tumor-intrinsic effect. Acquired resistance was not due to immunosuppression in the tumor immune microenvironment, disruptions in the antigen presentation machinery, or altered expression of immune checkpoints. Rather, EMT was associated with epigenetic and transcriptional silencing of interferon regulatory factor 6 (Irf6), which renders tumor cells less sensitive to the pro-apoptotic effects of TNF-α. These findings show how resistance to immunotherapy in PDAC can be acquired through plasticity programs that render tumor cells impervious to T cell killing.

Site-Dependent Immune Escape Due to Impaired Dendritic Cell Cross-Priming.

T-cell recognition of tumor neoantigens is critical for cancer immune surveillance and the efficacy of immunotherapy. Tumors can evade host immunity by altering their antigenicity or orchestrating an immunosuppressive microenvironment, leading to outgrowth of poorly immunogenic tumors through the well-established process of cancer immunoediting. Whether cancer immune surveillance and immunoediting depend on the tissue site of origin, however, is poorly understood. Herein, we studied T-cell-mediated surveillance of antigenic, clonal murine pancreatic adenocarcinoma cells expressing neoantigen. Whereas such tumors are robustly eliminated after subcutaneous or intravenous challenge, we observed selective immune escape within the pancreas and peritoneum. Tumor outgrowth occurred in the absence of immunoediting, and antitumor immunity could not be rescued by PD-1 or CTLA-4 checkpoint blockade. Instead, tumor escape was associated with diminished CD8+ T-cell priming by type I conventional dendritic cells (cDC1). Enhancing cDC1 cross-presentation by CD40 agonist treatment restored immunologic control by promoting T-cell priming and broadening T-cell responses through epitope spread. These findings demonstrate that immune escape of highly antigenic tumors can occur without immunoediting in a tissue-restricted manner and highlight barriers to cDC1-mediated T-cell priming imposed by certain microenvironments that must be addressed for successful combination immunotherapies.

Adult Pleomorphic Rhabdomyosarcomas: Assessing Outcomes Associated with Radiotherapy and Chemotherapy Use in the National Cancer Database.

PURPOSE: Practice patterns for treatment of localized adult pleomorphic rhabdomyosarcoma (PRMS) remain quite variable given its rarity. Current national guidelines recommend management similar to that of other high-grade soft tissue sarcomas (STS), which include surgery with perioperative radiation (RT) with or without chemotherapy. Using the National Cancer Database (NCDB), we assessed practice patterns and overall outcomes of patients with localized PRMS. Patients and Methods. Patients with stage II/III PRMS treated with surgical resection from 2004 to 2015 were identified from the NCDB. Predictors of RT and chemotherapy use were assessed using multivariable logistic regression analysis. The association of radiation and chemotherapy status on overall survival was assessed using Kaplan-Meier and Cox proportional hazards analyses. RESULTS: Of 243 total patients, RT and chemotherapy were not uniformly utilized, with 44% receiving chemotherapy and in those who did not undergo amputation 62% receiving RT. In those who did not undergo amputation, RT was associated with improved survival on both univariate (HR: 0.49, 95% CI 0.32-0.73, P < 0.001) and multivariate analysis (HR: 0.40, 95% CI 0.26-0.62, P < 0.001), corresponding to greater 5-year overall survival (59% vs. 38%, P < 0.001). Chemotherapy was associated with a higher rate of 5-year overall survival (63% vs. 39%, P < 0.001). However, the survival benefit of chemotherapy did not reach statistical significance on multivariate analysis (HR: 0.65, 95% CI 0.41-1.03, P=0.064). Notable predictors of omission of RT included female gender (OR: 0.40, 95% CI 0.22-0.74, P < 0.01) and age ≥ 70 (OR: 0.55, 95% CI 0.30-1.00, P=0.05). Correspondingly, factors associated with omission of chemotherapy included age ≥70 (OR: 0.17, 95% CI 0.08-0.39, P < 0.001). CONCLUSIONS: A significant proportion of patients with localized adult PRMS are not receiving RT. Likewise, use of chemotherapy was heterogeneous. Our findings note potential benefits and underutilization of RT, for which further investigation is warranted.

Sufficiency of CD40 activation and immune checkpoint blockade for T cell priming and tumor immunity.

Innate immune receptors such as toll-like receptors (TLRs) provide critical molecular links between innate cells and adaptive immune responses. Here, we studied the CD40 pathway as an alternative bridge between dendritic cells (DCs) and adaptive immunity in cancer. Using an experimental design free of chemo- or radiotherapy, we found CD40 activation with agonistic antibodies (⍺CD40) produced complete tumor regressions in a therapy-resistant pancreas cancer model, but only when combined with immune checkpoint blockade (ICB). This effect, unachievable with ICB alone, was independent of TLR, STING, or IFNAR pathways. Mechanistically, αCD40/ICB primed durable T cell responses, and efficacy required DCs and host expression of CD40. Moreover, ICB drove optimal generation of polyfunctional T cells in this "cold" tumor model, instead of rescuing T cell exhaustion. Thus, immunostimulation via αCD40 is sufficient to synergize with ICB for priming. Clinically, combination αCD40/ICB may extend efficacy in patients with "cold" and checkpoint-refractory tumors.

Lack of immunoediting in murine pancreatic cancer reversed with neoantigen.

In carcinogen-driven cancers, a high mutational burden results in neoepitopes that can be recognized immunologically. Such carcinogen-induced tumors may evade this immune response through "immunoediting," whereby tumors adapt to immune pressure and escape T cell-mediated killing. Many tumors lack a high neoepitope burden, and it remains unclear whether immunoediting occurs in such cases. Here, we evaluated T cell immunity in an autochthonous mouse model of pancreatic cancer and found a low mutational burden, absence of predicted neoepitopes derived from tumor mutations, and resistance to checkpoint immunotherapy. Spontaneous tumor progression was identical in the presence or absence of T cells. Moreover, tumors arising in T cell-depleted mice grew unchecked in immune-competent hosts. However, introduction of the neoantigen ovalbumin (OVA) led to tumor rejection and T cell memory, but this did not occur in OVA immune-tolerant mice. Thus, immunoediting does not occur in this mouse model - a likely consequence, not a cause, of absent neoepitopes. Because many human tumors also have a low missense mutational load and minimal neoepitope burden, our findings have clinical implications for the design of immunotherapy for patients with such tumors.

Preventing mental illness: closing the evidence-practice gap through workforce and services planning.

BACKGROUND: Mental illness is prevalent across the globe and affects multiple aspects of life. Despite advances in treatment, there is little evidence that prevalence rates of mental illness are falling. While the prevention of cardiovascular disease and cancers are common in the policy dialogue and in service delivery, the prevention of mental illness remains a neglected area. There is accumulating evidence that mental illness is at least partially preventable, with increasing recognition that its antecedents are often found in infancy, childhood, adolescence and youth, creating multiple opportunities into young adulthood for prevention. Developing valid and reproducible methods for translating the evidence base in mental illness prevention into actionable policy recommendations is a crucial step in taking the prevention agenda forward. METHOD: Building on an aetiological model of adult mental illness that emphasizes the importance of intervening during infancy, childhood, adolescence and youth, we adapted a workforce and service planning framework, originally applied to diabetes care, to the analysis of the workforce and service structures required for best-practice prevention of mental illness. RESULTS: The resulting framework consists of 6 steps that include identifying priority risk factors, profiling the population in terms of these risk factors to identify at-risk groups, matching these at-risk groups to best-practice interventions, translation of these interventions to competencies, translation of competencies to workforce and service estimates, and finally, exploring the policy implications of these workforce and services estimates. The framework outlines the specific tasks involved in translating the evidence-base in prevention, to clearly actionable workforce, service delivery and funding recommendations. CONCLUSIONS: The framework describes the means to deliver mental illness prevention that the literature indicates is achievable, and is the basis of an ongoing project to model the workforce and service structures required for mental illness prevention.

Type I interferon is selectively required by dendritic cells for immune rejection of tumors.

Cancer immunoediting is the process whereby the immune system suppresses neoplastic growth and shapes tumor immunogenicity. We previously reported that type I interferon (IFN-α/ß) plays a central role in this process and that hematopoietic cells represent critical targets of type I IFN's actions. However, the specific cells affected by IFN-α/ß and the functional processes that type I IFN induces remain undefined. Herein, we show that type I IFN is required to initiate the antitumor response and that its actions are temporally distinct from IFN-γ during cancer immunoediting. Using mixed bone marrow chimeric mice, we demonstrate that type I IFN sensitivity selectively within the innate immune compartment is essential for tumor-specific T cell priming and tumor elimination. We further show that mice lacking IFNAR1 (IFN-α/ß receptor 1) in dendritic cells (DCs; Itgax-Cre(+)Ifnar1(f/f) mice) cannot reject highly immunogenic tumor cells and that CD8α(+) DCs from these mice display defects in antigen cross-presentation to CD8(+) T cells. In contrast, mice depleted of NK cells or mice that lack IFNAR1 in granulocytes and macrophage populations reject these tumors normally. Thus, DCs and specifically CD8α(+) DCs are functionally relevant targets of endogenous type I IFN during lymphocyte-mediated tumor rejection.

Surgery in early Jewish history.

The Hebrew writings in early history are dedicated primarily to the explanations and elucidations of Jewish law. In the context of such laws, several medical and anatomical references are made that provide some clues to the medical practices of the day. In particular, this article serves to compile references made to surgical interventions within these texts. Particular attention is paid to the possible use of anesthetics, the environment and equipment utilized in surgery, as well as the indication of knowledge of infection and hygienic practices. An understanding of human morphology was necessary for many of these surgical practices.

Peripheral facial nerve communications and their clinical implications.

The facial nerve (CN VII) nerve follows a torturous and complex path from its emergence at the pontomedullary junction to its various destinations. It exhibits a highly variable and complicated branching pattern and forms communications with several other cranial nerves. The facial nerve forms most of these neural intercommunications with branches of all three divisions of the trigeminal nerve (CN V), including branches of the auriculotemporal, buccal, mental, lingual, infraorbital, zygomatic, and ophthalmic nerves. Furthermore, CN VII also communicates with branches of the vestibulocochlear nerve (CN VIII), glossopharyngeal nerve (CN IX), and vagus nerve (CN X) as well as with branches of the cervical plexus such as the great auricular, greater, and lesser occipital, and transverse cervical nerves. This review intends to explore the many communications between the facial nerve and other nerves along its course from the brainstem to its peripheral branches on the human face. Such connections may have importance during clinical examination and surgical procedures of the facial nerve. Knowledge of the anatomy of these neural connections may be particularly important in facial reconstructive surgery, neck dissection, and various nerve transfer procedures as well as for understanding the pathophysiology of various cranial, skull base, and neck disorders.

Batf3 deficiency reveals a critical role for CD8alpha+ dendritic cells in cytotoxic T cell immunity.

Although in vitro observations suggest that cross-presentation of antigens is mediated primarily by CD8alpha+ dendritic cells, in vivo analysis has been hampered by the lack of systems that selectively eliminate this cell lineage. We show that deletion of the transcription factor Batf3 ablated development of CD8alpha+ dendritic cells, allowing us to examine their role in immunity in vivo. Dendritic cells from Batf3-/- mice were defective in cross-presentation, and Batf3-/- mice lacked virus-specific CD8+ T cell responses to West Nile virus. Importantly, rejection of highly immunogenic syngeneic tumors was impaired in Batf3-/- mice. These results suggest an important role for CD8alpha+ dendritic cells and cross-presentation in responses to viruses and in tumor rejection.

Blocking monoclonal antibodies specific for mouse IFN-alpha/beta receptor subunit 1 (IFNAR-1) from mice immunized by in vivo hydrodynamic transfection.

Herein we report the generation of mouse monoclonal antibodies (mAbs) specific for the IFNAR-1 subunit of the mouse interferon-alpha/beta (IFN-alpha/beta) receptor (MAR1 mAbs) that block type I IFN receptor signaling and biologic response induction in vitro and in vivo. These mAbs were generated from Ifnar1 (/) mice immunized by in vivo hydrodynamic transfection with a plasmid encoding the extracellular domain (ECD) of murine IFNAR-1. All MAR1 mAbs bound native receptor expressed on cell surfaces and immunoprecipitated IFNAR-1 from solubilized cells, and two mAbs also detected IFNAR-1 by Western blot analysis. in vitro, the mAbs prevented ligand-induced intracellular signaling and induction of a variety of type I IFN-induced biologic responses but had no effect on IFN-gamma-induced responses. The most effective in vitro blocker, MAR1-5A3, also blocked type I IFN-induced antiviral, antimicrobial, and antitumor responses in vivo. We also explored whether murine IFNAR-1 surface expression required the presence of Tyk2. In contrast to Tyk2-deficient human cell lines, comparable IFNAR-1 expression was found on primary cells derived either from wild-type or Tyk2 (/) mice. These mAbs represent much needed tools to more clearly elucidate the biochemistry, cell biology, and physiologic function of the type I IFNs and their receptor in mediating host-protective immunity and immunopathology.

Interferon-gamma and cancer immunoediting.

Over the last 12 yr, we have shown that interferon-gamma and lymphocytes collaborate to regulate tumor development in mice. Specifically, we found that the immune system not only prevents the growth of primary (carcinogen-induced and spontaneous) and transplanted tumors but also sculpts the immunogenicity of tumors that form. These observations led us to refine the old and controversial "cancer immunosurveillance" hypothesis of Burnet and Thomas into one that we termed cancer immunoediting that better emphasizes the paradoxical host-protective and tumor-sculpting roles of immunity on developing tumors. Our current work focuses on defining the molecular mechanisms that underlie cancer immunoediting and exploring the implications of this process for cancer immunotherapy.

A critical function for type I interferons in cancer immunoediting.

'Cancer immunoediting' is a process wherein the immune system protects hosts against tumor development and facilitates outgrowth of tumors with reduced immunogenicity. Although interferon-gamma (IFN-gamma) is known to be involved in this process, the involvement of type I interferons (IFN-alpha/beta) has not been elucidated. We now show that, like IFN-gamma, endogenously produced IFN-alpha/beta was required for the prevention of the growth of primary carcinogen-induced and transplantable tumors. Although tumor cells are important IFN-gamma targets, they are not functionally relevant sites of the actions of the type I interferons. Instead, host hematopoietic cells are critical IFN-alpha/beta targets during development of protective antitumor responses. Therefore, type I interferons are important components of the cancer immunoediting process and function in a way that does not completely overlap the functions of IFN-gamma.

Three-tesla imaging of the knee: initial experience.

PURPOSE: To assess 3-T imaging of the knee. MATERIALS AND METHODS: We reviewed 357 3-T magnetic resonance images of the knee obtained using a dedicated knee coil. From 58 patients who had arthroscopy we determined the sensitivity and specificity for anterior cruciate ligament (ACL) tear and medial and lateral meniscal tear. RESULTS: A chemical shift artifact showed prominently at 3 T even after improvements had been made by increasing the bandwidth. For complete ACL tear the sensitivity was 100% (95% confidence interval, CI, 75.30-100.00), and the specificity was 97.9% (95% CI 87.7-99.9). For the medial meniscus the sensitivity was 100.00% (95% CI 90.0-100.00), and the specificity was 83.3%(95% CI 66.6-95.3). For the lateral meniscus the sensitivity was 66.7% (95% CI 38.4-88.2), and the specificity was 97.6% (95% CI 87.1-99.9). CONCLUSIONS: In general 3-T imaging allows a favorable display of anatomy and pathology. The lateral meniscus was assessed to be weaker than the other anatomic structures. Three-tesla imaging allows increased signal-to-noise ratio, increased resolution, and faster scanning times.