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Response to cancer immunotherapy in primary versus metastatic disease has not been well-studied. We found primary pancreatic ductal adenocarcinoma (PDA) is responsive to diverse immunotherapies whereas liver metastases are resistant. We discovered divergent immune landscapes in each compartment. Compared to primary tumor, liver metastases in both mice and humans are infiltrated by highly anergic T cells and MHCII lo IL10 + macrophages that are unable to present tumor-antigen. Moreover, a distinctive population of CD24 + CD44 - CD40 - B cells dominate liver metastases. These B cells are recruited to the metastatic milieu by Muc1 hi IL18 hi tumor cells, which are enriched >10-fold in liver metastases. Recruited B cells drive macrophage-mediated adaptive immune-tolerance via CD200 and BTLA. Depleting B cells or targeting CD200/BTLA enhanced macrophage and T-cell immunogenicity and enabled immunotherapeutic efficacy of liver metastases. Our data detail the mechanistic underpinnings for compartment-specific immunotherapy-responsiveness and suggest that primary PDA models are poor surrogates for evaluating immunity in advanced disease., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

KRAS is the most frequently mutated human oncogene, and KRAS inhibition has been a longtime goal. Recently, inhibitors were developed that bind KRASG12C-GDP and react with Cys-12 (G12C-Is). Using new affinity reagents to monitor KRASG12C activation and inhibitor engagement, we found that an SHP2 inhibitor (SHP2-I) increases KRAS-GDP occupancy, enhancing G12C-I efficacy. The SHP2-I abrogated RTK feedback signaling and adaptive resistance to G12C-Is in vitro, in xenografts, and in syngeneic KRASG12C-mutant pancreatic ductal adenocarcinoma (PDAC) and non-small cell lung cancer (NSCLC). SHP2-I/G12C-I combination evoked favorable but tumor site-specific changes in the immune microenvironment, decreasing myeloid suppressor cells, increasing CD8+ T cells, and sensitizing tumors to PD-1 blockade. Experiments using cells expressing inhibitor-resistant SHP2 showed that SHP2 inhibition in PDAC cells is required for PDAC regression and remodeling of the immune microenvironment but revealed direct inhibitory effects on tumor angiogenesis and vascularity. Our results demonstrate that SHP2-I/G12C-I combinations confer a substantial survival benefit in PDAC and NSCLC and identify additional potential combination strategies., Competing Interests: Disclosures: C.J.R. Foster reported grants from the National Institutes of Health during the conduct of the study. K-K. Wong reported "other" from G1 Therapeutics, Zentalis Therapeutics, and Epiphanes Therapeutics outside the submitted work, and has consulting/sponsored research agreements with the following: AstraZeneca, Janssen, Pfizer, Novartis, Merck, Ono, and Array (consulting and sponsored research); MedImmune, Mirati (which developed MRTX 1257), Takeda, TargImmune, and BMS (sponsored research only). B.G. Neel reported "other" from Navire Pharma, Northern Biologics, Ltd, Arvinas, Inc, Regeneron, Amgen, Inc, Mirati Therapeutics, Gilead Therapeutics, and Moderna outside the submitted work. In addition, B.G. Neel has a patent to PCT 63031457 pending. No other disclosures were reported., (© 2020 Fedele et al.)

Pancreatic ductal adenocarcinoma carries a dismal prognosis, and outcomes have improved little with modern therapeutics. Checkpoint-based immunotherapy has failed to elicit responses in the vast majority of patients with pancreatic cancer. Alongside tumor cell-intrinsic mechanisms associated with oncogenic KRAS-induced inflammation, the tolerogenic myeloid cell infiltrate has emerged as a critical impediment to adaptive antitumor immune responses. Furthermore, the discovery of an intratumoral microbiome and the elucidation of host-microbe interactions that curtail antitumor immunity also present opportunities for intervention. Here we review the mechanisms of immunotherapy resistance in pancreatic ductal adenocarcinoma and discuss strategies to directly augment T cell responses in parallel with myeloid cell- and microbiome-targeted approaches that may enable immune-mediated control of this malignancy.

Piezo1 is a mechanosensitive ion channel that has gained recognition for its role in regulating diverse physiological processes. However, the influence of Piezo1 in inflammatory disease, including infection and tumor immunity, is not well studied. We postulated that Piezo1 links physical forces to immune regulation in myeloid cells. We found signal transduction via Piezo1 in myeloid cells and established this channel as the primary sensor of mechanical stress in these cells. Global inhibition of Piezo1 with a peptide inhibitor was protective against both cancer and septic shock and resulted in a diminution in suppressive myeloid cells. Moreover, deletion of Piezo1 in myeloid cells protected against cancer and increased survival in polymicrobial sepsis. Mechanistically, we show that mechanical stimulation promotes Piezo1-dependent myeloid cell expansion by suppressing the retinoblastoma gene Rb1 We further show that Piezo1-mediated silencing of Rb1 is regulated via up-regulation of histone deacetylase 2. Collectively, our work uncovers Piezo1 as a targetable immune checkpoint that drives immunosuppressive myelopoiesis in cancer and infectious disease., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Background: Propofol is a short-acting anesthetic used to induce sedation in various ambulatory and inpatient surgical procedures. It is a US Food and Drug Administration approved lipid-based intravenous hypnotic agent, which has been used clinically for the induction and maintenance of anesthesia for over 3 decades. In addition to general anesthesia, it is used to sedate patients undergoing mechanical ventilation or short procedures such as endoscopy, transesophageal echocardiogram, and abscess drainage. An infrequent but serious complication of propofol is acute pancreatitis (AP), with potentially significant morbidity and possible mortality. In this review, we will discuss the proposed mechanisms of AP secondary to propofol, a number of reported cases, studies conducted, and treatment strategies., Areas of Uncertainty: There are several case reports in the literature that have shown an association between propofol and pancreatitis. The exact mechanism behind propofol-induced pancreatitis is not fully understood, but proposed mechanisms include hypertriglyceridemia (HTG), hypersensitivity, or direct pancreatic toxicity of the drug. Although the association of propofol and pancreatitis has not been proven conclusively, clinicians should be aware of this possible rare complication to prevent the devastating consequences of AP., Data Sources: We gathered articles on previously documented case reports and up-to-date studies on propofol-induced pancreatitis by searching databases such as PubMed and Google Scholar., Results: Based on previous studies and case reports, we suggest that propofol should be added to a list of drugs having a direct association with AP., Conclusions: Although, the mechanism of propofol-induced pancreatitis is not fully understood, and the causal relationship of propofol-induced hypertriglyceridemia or idiosyncratic drug reaction has remained unproven. Clinicians should be aware of the association between propofol and pancreatitis, and any patient presenting with abdominal pain after propofol infusion should be evaluated for AP and treated promptly to avoid complications.

Programmed cell death protein 1 (PD-1) ligation delimits immunogenic responses in T cells. However, the consequences of programmed cell death 1 ligand 1 (PD-L1) ligation in T cells are uncertain. We found that T cell expression of PD-L1 in cancer was regulated by tumor antigen and sterile inflammatory cues. PD-L1 + T cells exerted tumor-promoting tolerance via three distinct mechanisms: (1) binding of PD-L1 induced STAT3-dependent 'back-signaling' in CD4 + T cells, which prevented activation, reduced T H 1-polarization and directed T H 17-differentiation. PD-L1 signaling also induced an anergic T-bet - IFN-γ - phenotype in CD8 + T cells and was equally suppressive compared to PD-1 signaling; (2) PD-L1 + T cells restrained effector T cells via the canonical PD-L1-PD-1 axis and were sufficient to accelerate tumorigenesis, even in the absence of endogenous PD-L1; (3) PD-L1 + T cells engaged PD-1 + macrophages, inducing an alternative M2-like program, which had crippling effects on adaptive antitumor immunity. Collectively, we demonstrate that PD-L1 + T cells have diverse tolerogenic effects on tumor immunity.

The trend of e-cigarette use among teens is ever increasing. Here we show the dysbiotic oral microbial ecology in e-cigarette users influencing the local host immune environment compared with non-smoker controls and cigarette smokers. Using 16S rRNA high-throughput sequencing, we evaluated 119 human participants, 40 in each of the three cohorts, and found significantly altered beta-diversity in e-cigarette users (p = 0.006) when compared with never smokers or tobacco cigarette smokers. The abundance of Porphyromonas and Veillonella (p = 0.008) was higher among vapers. Interleukin (IL)-6 and IL-1β were highly elevated in e-cigarette users when compared with non-users. Epithelial cell-exposed e-cigarette aerosols were more susceptible for infection. In vitro infection model of premalignant Leuk-1 and malignant cell lines exposed to e-cigarette aerosol and challenged by Porphyromonas gingivalis and Fusobacterium nucleatum resulted in elevated inflammatory response. Our findings for the first time demonstrate that e-cigarette users are more prone to infection., Competing Interests: Declaration of Interests The authors declare no competing interests., (Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background and Aims: The recruitment and activation of inflammatory cells in the liver delineates the transition from hepatic steatosis to steatohepatitis (SH)., Approach and Results: We found that in SH, γδT cells are recruited to the liver by C-C chemokine receptor (CCR) 2, CCR5, and nucleotide-binding oligomerization domain-containing protein 2 signaling and are skewed toward an interleukin (IL)-17A + phenotype in an inducible costimulator (ICOS)/ICOS ligand-dependent manner. γδT cells exhibit a distinct Vγ4 + , PD1 + , Ly6C + CD44 + phenotype in SH. Moreover, γδT cells up-regulate both CD1d, which is necessary for lipid-based antigens presentation, and the free fatty acid receptor, CD36. γδT cells are stimulated to express IL-17A by palmitic acid and CD1d ligation. Deletion, depletion, and targeted interruption of γδT cell recruitment protects against diet-induced SH and accelerates disease resolution., Conclusions: We demonstrate that hepatic γδT cells exacerbate SH, independent of IL-17 expression, by mitigating conventional CD4 + T-cell expansion and modulating their inflammatory program by CD1d-dependent vascular endothelial growth factor expression., (© 2019 by the American Association for the Study of Liver Diseases.)

Bacterial dysbiosis accompanies carcinogenesis in malignancies such as colon and liver cancer, and has recently been implicated in the pathogenesis of pancreatic ductal adenocarcinoma (PDA) 1 . However, the mycobiome has not been clearly implicated in tumorigenesis. Here we show that fungi migrate from the gut lumen to the pancreas, and that this is implicated in the pathogenesis of PDA. PDA tumours in humans and mouse models of this cancer displayed an increase in fungi of about 3,000-fold compared to normal pancreatic tissue. The composition of the mycobiome of PDA tumours was distinct from that of the gut or normal pancreas on the basis of alpha- and beta-diversity indices. Specifically, the fungal community that infiltrated PDA tumours was markedly enriched for Malassezia spp. in both mice and humans. Ablation of the mycobiome was protective against tumour growth in slowly progressive and invasive models of PDA, and repopulation with a Malassezia species-but not species in the genera Candida, Saccharomyces or Aspergillus-accelerated oncogenesis. We also discovered that ligation of mannose-binding lectin (MBL), which binds to glycans of the fungal wall to activate the complement cascade, was required for oncogenic progression, whereas deletion of MBL or C3 in the extratumoral compartment-or knockdown of C3aR in tumour cells-were both protective against tumour growth. In addition, reprogramming of the mycobiome did not alter the progression of PDA in Mbl- (also known as Mbl2) or C3-deficient mice. Collectively, our work shows that pathogenic fungi promote PDA by driving the complement cascade through the activation of MBL.

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 ., (©2019 American Association for Cancer Research.)

Liver fibrosis and fibrosis-associated hepatocarcinogenesis are driven by chronic inflammation and are leading causes of morbidity and death worldwide. SYK signaling regulates critical processes in innate and adaptive immunity, as well as parenchymal cells. We discovered high SYK expression in the parenchymal hepatocyte, hepatic stellate cell (HSC), and the inflammatory compartments in the fibrotic liver. We postulated that targeting SYK would mitigate hepatic fibrosis and oncogenic progression. We found that inhibition of SYK with the selective small molecule inhibitors Piceatannol and PRT062607 markedly protected against toxin-induced hepatic fibrosis, associated hepatocellular injury and intra-hepatic inflammation, and hepatocarcinogenesis. SYK inhibition resulted in increased intra-tumoral expression of the p16 and p53 but decreased expression of Bcl-xL and SMAD4. Further, hepatic expression of genes regulating angiogenesis, apoptosis, cell cycle regulation, and cellular senescence were affected by targeting SYK. We found that SYK inhibition mitigated both HSC trans-differentiation and acquisition of an inflammatory phenotype in T cells, B cells, and myeloid cells. However, in vivo experiments employing selective targeted deletion of SYK indicated that only SYK deletion in the myeloid compartment was sufficient to confer protection against fibrogenic progression. Targeting SYK promoted myeloid cell differentiation into hepato-protective TNFα low CD206 hi phenotype downregulating mTOR, IL-8 signaling and oxidative phosphorylation. Collectively, these data suggest that SYK is an attractive target for experimental therapeutics in treating hepatic fibrosis and oncogenesis.

The drivers and the specification of CD4 + T cell differentiation in the tumor microenvironment and their contributions to tumor immunity or tolerance are incompletely understood. Using models of pancreatic ductal adenocarcinoma (PDA), we show that a distinct subset of tumor-infiltrating dendritic cells (DC) promotes PDA growth by directing a unique T H -program. Specifically, CD11b + CD103 - DC predominate in PDA, express high IL-23 and TGF-β, and induce FoxP3 neg tumor-promoting IL-10 + IL-17 + IFNγ +  regulatory CD4 + T cells. The balance between this distinctive T H program and canonical FoxP3 +  T REGS is unaffected by pattern recognition receptor ligation and is modulated by DC expression of retinoic acid. This T H -signature is mimicked in human PDA where it is associated with immune-tolerance and diminished patient survival. Our data suggest that CD11b + CD103 - DC promote CD4 + T cell tolerance in PDA which may underscore its resistance to immunotherapy.

Pancreatic ductal adenocarcinoma (PDA) is characterized by immune tolerance and immunotherapeutic resistance. We discovered upregulation of receptor-interacting serine/threonine protein kinase 1 (RIP1) in tumor-associated macrophages (TAMs) in PDA. To study its role in oncogenic progression, we developed a selective small-molecule RIP1 inhibitor with high in vivo exposure. Targeting RIP1 reprogrammed TAMs toward an MHCII hi TNFα + IFNγ + immunogenic phenotype in a STAT1-dependent manner. RIP1 inhibition in TAMs resulted in cytotoxic T cell activation and T helper cell differentiation toward a mixed Th1/Th17 phenotype, leading to tumor immunity in mice and in organotypic models of human PDA. Targeting RIP1 synergized with PD1-and inducible co-stimulator-based immunotherapies. Tumor-promoting effects of RIP1 were independent of its co-association with RIP3. Collectively, our work describes RIP1 as a checkpoint kinase governing tumor immunity., (Copyright © 2018 Elsevier Inc. All rights reserved.)

We found that the cancerous pancreas harbors a markedly more abundant microbiome compared with normal pancreas in both mice and humans, and select bacteria are differentially increased in the tumorous pancreas compared with gut. Ablation of the microbiome protects against preinvasive and invasive pancreatic ductal adenocarcinoma (PDA), whereas transfer of bacteria from PDA-bearing hosts, but not controls, reverses tumor protection. Bacterial ablation was associated with immunogenic reprogramming of the PDA tumor microenvironment, including a reduction in myeloid-derived suppressor cells and an increase in M1 macrophage differentiation, promoting TH1 differentiation of CD4 + T cells and CD8 + T-cell activation. Bacterial ablation also enabled efficacy for checkpoint-targeted immunotherapy by upregulating PD-1 expression. Mechanistically, the PDA microbiome generated a tolerogenic immune program by differentially activating select Toll-like receptors in monocytic cells. These data suggest that endogenous microbiota promote the crippling immune-suppression characteristic of PDA and that the microbiome has potential as a therapeutic target in the modulation of disease progression. Significance: We found that a distinct and abundant microbiome drives suppressive monocytic cellular differentiation in pancreatic cancer via selective Toll-like receptor ligation leading to T-cell anergy. Targeting the microbiome protects against oncogenesis, reverses intratumoral immune tolerance, and enables efficacy for checkpoint-based immunotherapy. These data have implications for understanding immune suppression in pancreatic cancer and its reversal in the clinic. Cancer Discov; 8(4); 403-16. ©2018 AACR. See related commentary by Riquelme et al., p. 386 This article is highlighted in the In This Issue feature, p. 371 ., (©2018 American Association for Cancer Research.)

Background: Psychosocial evaluation is an important part of the live organ donor evaluation process, yet it is not standardized across institutions, and although tools exist for the psychosocial evaluation of organ recipients, none exist to assess donors., Objective: We set out to develop a semistructured psychosocial evaluation tool (the Live Donor Assessment Tool, LDAT) to assess potential live organ donors and to conduct preliminary analyses of the tool's reliability and validity., Methods: Review of the literature on the psychosocial variables associated with treatment adherence, quality of life, live organ donation outcome, and resilience, as well as review of the procedures for psychosocial evaluation at our center and other centers around the country, identified 9 domains to address; these domains were distilled into several items each, in collaboration with colleagues at transplant centers across the country, for a total of 29 items. Four raters were trained to use the LDAT, and they retrospectively scored 99 psychosocial evaluations conducted on live organ donor candidates. Reliability of the LDAT was assessed by calculating the internal consistency of the items in the scale and interrater reliability between raters; validity was estimated by comparing LDAT scores between those with a "positive" evaluation outcome and "negative" outcome., Results: The LDAT was found to have good internal consistency, inter-rater reliability, and showed signs of validity: LDAT scores differentiated the positive vs. negative outcome groups., Conclusions: The LDAT demonstrated good reliability and validity, but future research on the LDAT and the ability to implement the LDAT prospectively is warranted., (Copyright © 2015 The Academy of Psychosomatic Medicine. Published by Elsevier Inc. All rights reserved.)