Malignant pleural effusions, arising from either primary mesotheliomas or secondary malignancies, heralds advanced disease and poor prognosis. Current treatments, including therapeutic thoracentesis and tube thoracostomy, are largely palliative. The immunosuppressive environment within the pleural cavity includes myeloid derived suppressor cells, T-regulatory cells, and dysfunctional T cells. The advent of effective immunotherapy with checkpoint inhibitors and adoptive cell therapies for lung cancer and other malignancies suggests a renewed examination of local and systemic therapies for this malady. Prior strategies reporting remarkable success, including instillation of the cytokine interleukin-2, perhaps coupled with checkpoint inhibitors, should be further evaluated in the modern era.

Platelets are activated in solid cancers, including pancreatic ductal adenocarcinoma (PDA), a highly aggressive malignancy with a devastating prognosis and limited therapeutic options. The mechanisms by which activated platelets regulate tumor progression are poorly understood. The nucleotide-binding domain leucine-rich repeat containing protein 3 (NLRP3) inflammasome is a key inflammatory mechanism recently identified in platelets, which controls platelet activation and aggregation. In an orthotopic PDA mouse model involving surgical implantation of Panc02 murine cancer cells into the tail of the pancreas, we show that the NLRP3 inflammasome in circulating platelets is upregulated in pancreatic cancer. Pharmacological inhibition or genetic ablation of NLRP3 in platelets resulted in decreased platelet activation, platelet aggregation, and tumor progression. Moreover, interfering with platelet NLRP3 signaling significantly improved survival Sebastian Vogel,

Thoracic malignancies are associated with high mortality rates. Conventional therapy for many of the patients with thoracic malignancies is obviated by a high incidence of locoregional recurrence and distant metastasis. Fortunately, developments in immunotherapy provide effective strategies for both local and systemic treatments that have rapidly advanced during the last decade. One promising approach to cancer immunotherapy is to use oncolytic viruses, which have the advantages of relatively high tumor specificity, selective replication-mediated oncolysis, enhanced antigen presentation, and potential for delivery of immunogenic payloads such as cytokines, with subsequent elicitation of effective antitumor immunity. Several oncolytic viruses including adenovirus, coxsackievirus B3, herpes virus, measles virus, reovirus, and vaccinia virus have been developed and applied to thoracic cancers in preclinical murine studies and clinical trials. This review discusses the current state of oncolytic virotherapy in lung cancer, esophageal cancer, and metastatic malignant pleural effusions and considers its potential as an emergent therapeutic for these patients.

Objective: The mainstay of treatment for patients with malignant pleural disease is fluid drainage and systemic therapy. A tumor-specific oncolytic virus or T-cell-activating interleukin-2 immunotherapy may provide an opportunity for local control. We previously developed a vaccinia virus-expressing interleukin-2, an oncolytic virus that mediated tumor regression in preclinical peritoneal tumor models with expansion of tumor-infiltrating lymphocytes. We evaluated the antitumor efficacy and immune modulatory effects of vaccinia virus-expressing interleukin-2 in malignant pleural disease.Methods: A murine model of malignant pleural disease was established with percutaneous intrapleural deposition of the Lewis lung carcinoma cell line and monitored with bioluminescent imaging. After intrapleural or systemic administration of vaccinia viruses (vaccinia virus yellow fluorescent protein control, vaccinia virus-expressing interleukin-2), systemic anti-programmed cell death-1 antibody, or combination therapy (vaccinia virus-expressing interleukin-2 and anti-programmed cell death-1), tumor mass, immune cell infiltration, T-cell receptor diversity, and survival were assessed.Results: Intrapleural vaccinia virus resulted in significant tumor regression compared with phosphate-buffered saline control (P < .05). Inclusion of the interleukin-2 transgene further increased intratumoral CD8 þ T cells (P < .01) and programmed cell death-1 expression on CD8 þ tumor-infiltrating lymphocytes (P < .001). Intrapleural vaccinia virus-expressing interleukin-2 was superior to systemic vaccinia virus-expressing interleukin-2, with reduced tumor burden (P < .0001) and improved survival (P < .05). Intrapleural vaccinia virus-expressing interleukin-2 alone or combined treatment with systemic TCR Vβ DiversityαPD-1

The clear cell subtype of kidney cancer encompasses most renal cell carcinoma cases and is associated with the loss of von Hippel-Lindau gene function or expression. Subsequent loss or mutation of the other allele influences cellular stress responses involving nutrient and hypoxia sensing. Autophagy is an important regulatory process promoting the disposal of unnecessary or degraded cellular components, tightly linked to almost all cellular processes. Organelles and proteins that become damaged or that are no longer needed in the cell are sequestered and digested in autophagosomes upon fusing with lysosomes, or alternatively, released via vesicular exocytosis. Tumor development tends to disrupt the regulation of the balance between this process and apoptosis, permitting prolonged cell survival and increased replication. Completed trials of autophagic inhibitors using hydroxychloroquine in combination with other anticancer agents including rapalogues and high-dose interleukin 2 have now been reported. The complex nature of autophagy and the unique biology of clear cell renal cell carcinoma warrant further understanding to better develop the next generation of relevant anticancer agents.

Pleural effusions, when benign, are attributed to cardiac events and suffusion of fluid within the pleural space. When malignant, lymphatic obstruction by tumor and failure to absorb constitutively produced fluid is the predominant formulation. The prevailing view has been challenged recently, namely that the lymphatics are only passive vessels, carrying antigenic fluid to secondary lymphoid sites. Rather, lymphatic vessels can be a selective barrier, efficiently coordinating egress of immune cells and factors within tissues, limiting tumor spread and immune pathology. An alternative explanation, offered here, is that damage associated molecular pattern molecules, released in excess, maintain a local milieu associated with recruitment and retention of immune cells associated with failed lymphatic clearance and functional lymphatic obstruction. We found that levels of high mobility group box 1 (HMGB1) were equally elevated in both benign and malignant pleural effusions (MPEs) and that limited diversity of T cell receptor expressing gamma and delta chain were inversely associated with these levels in MPEs. Acellular fluid from MPEs enhanced γδ T cell proliferation in vitro, while inhibiting cytokine production from γδ T cells and monocytes as well as restricting monocyte chemotaxis. Novel therapeutic strategies, targeting HMGB1 and its neutralization in such effusions as well as direct delivery of immune cells into the pleural space to reconstitute normal physiology should be considered.

BackgroundPancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy, characterized by a desmoplastic stromal reaction and an immunosuppressive tumor microenvironment (TME)1. The metabolic stress within the PDAC TME promotes autophagy, a form of programmed cell survival associated with chemotherapeutic resistance and immune evasion.2, 3MethodsWe conducted a randomized phase II study of preoperative gemcitabine and nab-paclitaxel with or without autophagy inhibition with oral hydroxychloroquine (HCQ) in patients with resectable PDAC. Autophagy inhibition increased Evans Grade histopathologic response and immune infiltrate.4Utilizing multiplex immunohistochemistry and dimer avoidance multiplex PCR-NGS5 in a subset of RNA extracted FFPE tumor specimens, we evaluated the adaptive immune response and immune correlates of response.ResultsPatients receiving HCQ had a greater CD4/CD8 immune infiltration (p = 0.033). Independent of treatment, a higher tumor immune infiltration score,6 was associated with improved overall survival (p = 0.035). Bulk tumor immunosequencing revealed a clonally expanded T cell receptor (TCR) Vβ (115±84 unique CDR3s (uCDR3s) of 3.3 × 104±2.4 total CDR3s) and B cell receptor (BCR) IgH (9.8 × 104±5.2 uCDR3s of 1.4 × 105±0.76 total CDR3s) repertoire compared to a paucity of TCR Vδ clones (2±1 uCDR3s of 43±60 total CDR3s). Patients with a higher than median TCR Vβ Diversity 50 Index (D50, proportion of uCDR3s that make up 50% of the total CDR3s) had significantly higher tumor CD4 (p = 0.003) and CD8 (p = 0.031) counts. Patients with a higher than median TRC Vβ D50 also had a reduced lymph node ratio (p = 0.039) and greater overall survival (p = 0.037, figure 1). Conversely, patients with a higher than median BCR IgH D50 had worse overall survival (p = 0.0241). Given the dichotomy of the TCR and BCR repertoire diversity and association with clinical outcome, we further analyzed the individual ratio of TRC Vβ:BCR IgH CDR3s and found that patients with a higher than median TRC Vβ:BCR IgH ratio had a greater Evan’s Grade histopathologic response (p = 0.069).Abstract 260 Figure 1Following neoadjuvant therapy, patients with resectable pancreatic cancer with a higher than median intratumoral TCR Vβ Diversity 50 (n=9, 4.624 HR; 95 CI [0.971, 21.83]) have greater overall survival compared to patients with lower than median intratumoral TCR Vβ Diversity 50 (n=10, 0.2163 HR; 95 CI [0.458, 1.021]). Representative tree maps of high and low TRC Vβ D50, where each rounded rectangle represents a unique CDR3, with the size of the rectangle corresponding to the relative frequency of the CDR3 clones across the entire repertoireConclusionsPDAC TIL repertoire with high TCR Vβ diversity is associated with decreased positive lymph node ratio and greater overall survival following neoadjuvant therapy. The divergent outcomes associated with increased intratumoral TCR and BCR diversity suggest a host response that may favor opposing T and B cell lymphocytic expansion. Regulation of this relationship may be explained by tumor MHC class I expression[3] or the presence of CD141+ cross presenting dendritic cells7, 8 and tertiary lymphoid structures,9 currently under investigation. Examination of repertoire modulating therapies is warranted.Trial RegistrationThis trial (NCT01978184) was approved by the protocol review committee and IRB 13–074 at the University of Pittsburgh and performed in full accordance with the guidelines for good clinical practice and the Declaration of Helsinki. Written informed consent was obtained from all patients prior to any protocol treatment.ReferencesHo WJ, Jaffee EM, Zheng L. The tumour microenvironment in pancreatic cancer - clinical challenges and opportunities. Nat Rev Clin Oncol 2020;17(9):527–540.Boone BA, Zeh HJ, 3rd, Bahary N. Autophagy inhibition in pancreatic adenocarcinoma. Clin Colorectal Cancer 2018;17(1):25–31.Yamamoto K, Venida A, Yano J, et al. Autophagy promotes immune evasion of pancreatic cancer by degrading MHC-I. Nature 2020;581(7806):100–105.Zeh HJ, Bahary N, Boone BA, et al. A Randomized phase ii preoperative study of autophagy inhibition with high-dose hydroxychloroquine and gemcitabine/nab-paclitaxel in pancreatic cancer patients. Clin Cancer Res 2020;26(13):3126–3134.Han J, Lotze MT. The adaptome as biomarker for assessing cancer immunity and immunotherapy. Methods Mol Biol2020; 2055:369–397.Hwang WT, Adams SF, Tahirovic E, Hagemann IS, Coukos G. Prognostic significance of tumor-infiltrating T cells in ovarian cancer: a meta-analysis. Gynecol Oncol. 2012;124(2):192–198.Spranger S, Dai D, Horton B, Gajewski TF. Tumor-Residing Batf3 Dendritic Cells Are Required for Effector T Cell Trafficking and Adoptive T Cell Therapy. Cancer Cell 2017;31(5):711–723 e714.Jang JE, Hajdu CH, Liot C, Miller G, Dustin ML, Bar-Sagi D. Crosstalk between regulatory T cells and tumor-associated dendritic cells negates anti-tumor immunity in pancreatic cancer. Cell Rep 2017;20(3):558–571.Bruno TC. New predictors for immunotherapy responses sharpen our view of the tumour microenvironment. Nature 2020;577(7791):474–476.