Jagged2 targeting in lung cancer activates anti-tumor immunity via Notch-induced functional reprogramming of tumor-associated macrophages

Signaling through Notch receptors intrinsically regulates tumor cell development and growth. Here, we studied the role of the Notch ligand Jagged2 on immune evasion in non-small cell lung cancer (NSCLC). Higher expression of JAG2 in NSCLC negatively correlated with survival. In NSCLC pre-clinical models, deletion of Jag2, but not Jag1, in cancer cells attenuated tumor growth and activated protective anti-tumor T cell responses. Jag2-/- lung tumors exhibited higher frequencies of macrophages that expressed immunostimulatory mediators and triggered T cell-dependent anti-tumor immunity. Mechanistically, Jag2 ablation promoted Nr4a-mediated induction of Notch ligands DLL1/4 on cancer cells. DLL1/4-initiated Notch1/2 signaling in macrophages induced the expression of transcription factor IRF4 and macrophage immunostimulatory functionality. IRF4 expression was required for the anti-tumor effects of Jag2 deletion in lung tumors. Antibody targeting of Jagged2 inhibited tumor growth and activated IRF4-driven macrophage-mediated anti-tumor immunity. Thus, Jagged2 orchestrates immunosuppressive systems in NSCLC that can be overcome to incite macrophage-mediated anti-tumor immunity.

The Role of Point-of-Care Testing to Improve Acute Care and Health Care Services

Health care is one of the most important services that need to be provided to any community. Many challenges exist in delivering proper and effective health services, including ensuring timely delivery, providing adequate care through effective management and achieving good outcomes. Point-of-care testing (POCT) plays a crucial role in delivering urgent and appropriate health services, especially in peripheral communities, emergency situations, disaster areas and overcrowded areas. We collected and reviewed secondary data about point-of-care testing from PubMed, Scopus and Google Scholar. Our findings emphasize that POCT provides fast care with minimal waiting time, avoids unnecessary investigations, aids in triage, and provides decision-makers with a clear understanding of the patient's condition to make informed decisions. We recommend point-of-care testing as a frontline investigation in emergency departments, intensive care units, peripheral hospitals, primary health care centers, disaster areas and field hospitals. Point-of-care testing can improve the quality of health services and ensure the provision of necessary health care.

Metabolites alterations associated with obesity: A scoping review

INTRODUCTION

Obesity can be considered a major public health concern throughout the world. Various studies have been conducted to combat the rising number of cases of this health problem. Therefore, identifying the roots of the disease is critical in developing the desperately needed treatment approaches. However, in order to fully understand the origin of this disease, figuring out the metabolites present, and the alterations that occurred in a particular metabolism are crucial, and the information regarding the metabolites involved is limited. The aim of this study is to analyse the literature relevant to the metabolites involved in obesity conditions through a scoping review.

MATERIALS AND METHODS

This review utilises three databases (SCOPUS, Science Direct, and PubMed). The search phrases used are (Metabolomic* OR Metabolite*) for metabolomic study, (3T3-L1 OR Adipocyte OR "Adipose Tissue") for experimental design, and (Obesity) for obesity condition. Each of the search keywords was separated by an "AND" term in the databases. Other terms related to obesity, such as insulin resistance, heart disease, type 2 diabetes, muscular disorders, respiratory problems, and psychological problems were omitted because they did not contribute to the total number of studies discovered.

RESULTS

A total of 27 research publications were included in this scoping review. Most of the study focuses on metabolomics in obesity. Metabolites detected were found in various metabolic pathways including amino acids, carbohydrates, lipids as well as other metabolisms. Most of these metabolites discovered in obese conditions showed an alteration when compared to the level of the metabolite in normal conditions.

CONCLUSION

Unfortunately, these studies had some limitations in which the metabolites detected varied between the articles and the information concerning the relationship between the technique or instrument utilised and the metabolites detected in the samples were not well described. Therefore, using the findings obtained in this study, it can help to determine the direction of the study in the future.

Larvicidal potential of plant-based extracts against dengue vector: A short review

INTRODUCTION

Dengue fever, a vector borne disease transmitted primarily by Aedes albopictus and Aedes aegypti mosquitoes, has triggered a significant global resurgence. While many vector control programs depend on the use of chemical insecticides to curb outbreaks, its heavy reliance raises environmental concerns and the risk of insecticide resistance. Alternatively, botanically derived insecticidal agents with larvicidal properties offer an ecofriendlier option. This review aims to analyze scientific reports that described the effectiveness of plant-derived extracts for vector control.

MATERIALS AND METHODS

A literature search was performed to analyze studies that focused on plant-based extracts used for larvicidal purposes using databases such as Science Direct. Springer, PubMed, and Scopus. The inclusion criteria for publications were larvicidal effects, published in English from the year 2017 and availability of full-text articles. The available literature was further characterized by the value of larvicidal activities of LC50 and LC90 (< 50 ppm), of 22 different parts of plant species from 7 plant families namely Apiaceae, Asteraceae, Lauraceae, Magnoliaceae, Myrtaceae, Piperaceae and Rubiaceae.

RESULTS

When comparing the values of LC50, 12 plants species (Artemisia vulgaris, Crassocephalum crepidioides, Echinops grijsii, Melaleuca leucadendra, Neolitsea ellipsoidea, Pavetta tomentosa, Piper betle, Piper caninum, Piper Montium, Piper muntabile, Piper ovatum, Tarenna asiatica) showed promising larvicidal efficacies with LC50 < 10 ppm.

CONCLUSION

This review emphasizes the effective alternatives of plant extracts for the potential production of larvicides. Piper betle extract and chloroform extract of Tarenna asiatica reported the most significant larvicidal activity (LC50 < 1 ppm) against mosquito vectors. Further reviews focusing on the mode of actions of its phytochemically constituents are essential for the future development of potentially significant plant-based larvicides.

Phytochemical quantification and HPLC analysis of Parkia speciosa pod extract

INTRODUCTION

Parkia speciosa Hassk., commonly known as bitter bean or twisted cluster bean, is a tropical leguminous plant species native to Southeast Asia. The plant's edible pods have been traditionally used in various cuisines, particularly in Malaysian, Thai, and Indonesian cooking. Apart from being used as a food ingredient, the pods of P. speciosa also have a range of potential applications in other fields, including medicine, agriculture, and industry. The pods are said to have several phytochemicals that hold great therapeutic values such as reducing inflammation, improving digestion, and lowering blood sugar levels. However, there is limited information on the specific phytochemical contents of the pods in the literature. Thus, the aim of this study is to quantify the total phenolic and flavonoid compounds and to determine the concentrations of four selected phytochemical compounds in the P. speciosa pod extract (PSPE).

MATERIALS AND METHODS

Quantification of the total phenolic (TPC) and flavonoid contents (TFC) in PSPE were done via colourimetric methods; and the determination of the concentrations of four specific phytochemicals (gallic acid, caffeic acid, rutin, and quercetin) were done via High- Performance Liquid Chromatography (HPLC).

RESULTS

Colourimetric determination of PSPE showed TPC and TFC values of 84.53±9.40 mg GAE/g and 11.96±4.51 mg QE/g, respectively. Additional analysis of the phytochemicals using HPLC revealed that there were 6.45±3.36 g/kg, 5.91±1.07 g/kg, 0.39±0.84 g/kg, and 0.19±0.47 g/kg of caffeic acid, gallic acid, rutin, and quercetin, respectively.

CONCLUSION

The findings show that PSPE contains substantial amounts of caffeic acid, gallic acid, rutin, and quercetin, which may indicate its potential as antibacterial, anti-inflammatory, anti-lipid, and antiviral medicines.

Clinico-Pathological Features and Immunohistochemical Comparison of p16, p53, and Ki-67 Expression in Muscle-Invasive and Non-Muscle-Invasive Conventional Urothelial Bladder Carcinoma

INTRODUCTION

The identification of bladder detrusor muscle invasion in urothelial cancer is essential for prognosis and management. We studied the clinical, histological, and immunohistochemical expression of p16, p53, and Ki-67 in urothelial detrusor muscle-invasive bladder cancer (MIBC) and urothelial non-detrusor muscle-invasive bladder cancer (NMIBC) in Egyptian patients.

METHODS

Sixty-two bladder urothelial cancer cases obtained through TURBT were included and divided into two groups: (MIBC, stage T2) and NMIBC (T1). Tissue blocks were recut and re-examined microscopically; then, the immunostaining of p16, p53, and Ki-67 was performed to compare both groups and evaluate the 13% cut-off for Ki-67, 20% for p53, and p16 intensity in various conditions aided by telepathology technology.

RESULTS AND CONCLUSION

Hematuria was the main clinical first presentation, with no significant difference between either group. The mean age was 61.6 years, with male predominance (52 males and 10 females). The absence of papillary histological pattern was associated with a higher stage, including detrusor muscle invasion (p = 0.000). The overall average percent of p53 immunostaining was 12.9%, revealing no significant difference between MIBC and NMIBC when a cut-off of 20% was implicated. The Ki-67 expression was correlated with higher grade and muscle invasion; however, no association was found with the other two markers' expression. The negative immunostaining of p16 was associated with low grade and NMIBC in the case of the preservation of the papillary pattern. We recommend further studies on the cut-off of widely used markers and more immunohistochemical and genetic studies on the p16(INK4A), taking into consideration the histological pattern of conventional carcinomas.

HER2/neu expression status of post BCG recurrent non-muscle-invasive bladder urothelial carcinomas in relation to their primary ones

BACKGROUND

Transurethral resection (TUR) followed by adjuvant therapy is still the treatment of choice of Non-Muscle-Invasive Bladder Urothelial Carcinoma (NMIBUC). However, recurrence is one of the most troublesome features of these lesions. Early second resection and adjuvant BCG therapy has been shown to improve the outcome.

OBJECTIVE

To evaluate the prognostic value of C-erbB-2 (HER2/neu) expression status in Non-Muscle-Invasive Bladder Urothelial Carcinoma cases, before and after intravesical Bacillus Calmette Guerin (BCG immunotherapy).

MATERIALS AND METHODS

HER2/neu expression was studied in 120 (Ta-T1) Non-Muscle-Invasive Urothelial Carcinoma cases. The expression was evaluated and compared to the expression after Bacillus Calmette Guerin (BCG) immunotherapy.

RESULTS

HER2/neu expression in low and high grade of the Non- Muscle-Invasive Urothelial Carcinoma was (38%) and (83%) respectively. The difference of the expression rates by tumor grade was statistically significant. In recurring lesions post BCG therapy, C-erbB-2 expression was markedly decreased (31.6%) when compared to its expression before therapy (65%).

CONCLUSIONS

The HER2/neu expression increased as the tumor grade rose. The reduction in expression following BCG treatment in Non-Invasive transitional cell carcinoma cases could reflect a reduction of the potential malignancy of the tumor.

Ablation of the endoplasmic reticulum stress kinase PERK induces paraptosis and type I interferon to promote anti-tumor T cell responses

Activation of unfolded protein responses (UPRs) in cancer cells undergoing endoplasmic reticulum (ER) stress promotes survival. However, how UPR in tumor cells impacts anti-tumor immune responses remains poorly described. Here, we investigate the role of the UPR mediator pancreatic ER kinase (PKR)-like ER kinase (PERK) in cancer cells in the modulation of anti-tumor immunity. Deletion of PERK in cancer cells or pharmacological inhibition of PERK in melanoma-bearing mice incites robust activation of anti-tumor T cell immunity and attenuates tumor growth. PERK elimination in ER-stressed malignant cells triggers SEC61β-induced paraptosis, thereby promoting immunogenic cell death (ICD) and systemic anti-tumor responses. ICD induction in PERK-ablated tumors stimulates type I interferon production in dendritic cells (DCs), which primes CCR2-dependent tumor trafficking of common-monocytic precursors and their intra-tumor commitment into monocytic-lineage inflammatory Ly6C+CD103+ DCs. These findings identify how tumor cell-derived PERK promotes immune evasion and highlight the potential of PERK-targeting therapies in cancer immunotherapy.

O049 FRAX score assessment of long term follow up thyroid cancer patients

Introduction

Thyroid stimulating hormone (TSH) suppression with Levothyroxine (LT4) following thyroid cancer surgery is recommended in some patients under long term follow up. However, LT4 may cause reduced bone mineral density. We aimed to assess patients in our long-term thyroid cancer follow up clinic for risk to bone health.

Methods

We conducted a review of all patients in the thyroid cancer follow-up clinic and calculation of FRAX score for those that are &gt;40 years old who are followed up in the Endocrine Surgical Service of NUH. Subsequently patients were categorised into risk groups according to the Osteoporosis Group Guideline (2017) and managed accordingly.

Results

78 patients were identified and had ongoing follow up. 23 patients were excluded as they were &lt;40 years old. 10 patients did not want to participate in the study. 45 patients were assessed with the FRAX score. There were 31 female and 14 male patients, mean age 60.8 (±12.3) years. The mean follow up was 75.0 (±78.9) months. 11% (five patients) were found to require treatment for Osteoporosis without a bone mineral density (BMD) scan, 38% (17 patients) were recommended to assess their BMD, 4% had borderline risk to measure BMD, and 47% required lifestyle and dietary modification.

Conclusion

Thyroid cancer patients aged 40 and above represent a cohort in whom osteoporosis is a substantial risk and warrant assessment with a FRAX score.

Take-home message

Thyroid cancer patients aged 40 and above represent a cohort in whom osteoporosis is a substantial risk and warrant assessment with a FRAX score.

POS1292 ULTRASONOGRAPHIC GUIDED INTRA ARTICULAR STEROID AND HYALURONIC ACID IN ADHESIVE CAPSULITIS WITH AND WITHOUT SUPRASCAPULAR NERVE BLOCK

Background

Adhesive capsulitis (AC), often known as frozen shoulder, is a common musculoskeletal condition characterised by shoulder pain and reduced active and passive mobility. Intra-articular injections is an effective treatment option and provide faster pain relief in patients with AC

Objectives

Compare the effictiveness of intra articular injection (IAI) of steroid and HA with or without Suprascapular nerve block (SSNB) in the management of AC.

Methods

Randomized control trial involved 80 patients (62 women and 18 men) clinically diagnosed as having adhesive capsulitis divided into 2 main groups; intra articular injection with SSNB (40 cases) and without SSNB (40 cases), each group divided into 2 subgroups; Twenty patients were treated with ultrasound guided intra articular injection of steroid (4ml of 2% lidocaine and 2 ml of 40 mg/ml triamcinolone) and another twenty patients were treated with ultrasound guided intra articular injection of hyaluronic acid (4 ml of 2% lidocaine and 2 ml hyaluronic acid).

Results

Intra articular shoulder injection with SSNB has higher significant visual analogue scale (VAS) score at baseline and lower significant VAS score at 1st and 3rd week (p < 0.001). However, there was no significance between both groups regarding disability score at 3rd weak (p=0.316). In contrast, there was a high significance between them considering disability score at baseline, 1st, 6th weak (p<0.001 and 0.008, respectively).

Conclusion

In patients with adhesive capsulitis, both a combination an IAI alone or with SSNB dramatically improved pain and functional results. The use of an SSNB in conjunction with an IAI especially with steroid enhanced therapeutic effectiveness.

References

[1]D’Orsi GM, Via AG, Frizziero A, Oliva F. Treatment of adhesive capsulitis: a review. MLTJ. 2012; 2(2):70-78.

[2]Kingston K, Curry EJ, Galvin JW, Li X. Shoulder adhesive capsulitis: epidemiology and predictors of surgery. J Shoulder Elbow Surg. 2018 Aug;27(8):1437-1443.

[3]Zreik NH, Malik RA and Charalambous CP. Adhesive capsulitis of the shoulder and diabetes:a meta-analysis of prevalence. MLTJ. 2016;6 (1):26-34.

[4]Rangan A, Hanchard N, McDaid C. What is the most effective treatment for frozen shoulder? BMJ 2016;354:i4162.

Disclosure of Interests

None declared

The inhibitory receptor TIM-3 limits activation of the cGAS-STING pathway in intra-tumoral dendritic cells by suppressing extracellular DNA uptake

Blockade of the inhibitory receptor TIM-3 shows efficacy in cancer immunotherapy clinical trials. TIM-3 inhibits production of the chemokine CXCL9 by XCR1⁺ classical dendritic cells (cDC1), thereby limiting antitumor immunity in mammary carcinomas. We found that increased CXCL9 expression by splenic cDC1s upon TIM-3 blockade required type I interferons and extracellular DNA. Chemokine expression as well as combinatorial efficacy of TIM-3 blockade and paclitaxel chemotherapy were impaired by deletion of Cgas and Sting. TIM-3 blockade increased uptake of extracellular DNA by cDC1 through an endocytic process that resulted in cytoplasmic localization. DNA uptake and efficacy of TIM-3 blockade required DNA binding by HMGB1, while galectin-9-induced cell surface clustering of TIM-3 was necessary for its suppressive function. Human peripheral blood cDC1s also took up extracellular DNA upon TIM-3 blockade. Thus, TIM-3 regulates endocytosis of extracellular DNA and activation of the cytoplasmic DNA sensing cGAS-STING pathway in cDC1s, with implications for understanding the mechanisms underlying TIM-3 immunotherapy.

809 Evaluation of the Two Week Wait Colorectal Cancer Pathway in a District General Hospital

Introduction

Updated guidelines published by the National Institute for Health and Care Excellence in 2015 widened the referral criteria for the two week wait (2WW) pathway for suspected lower gastrointestinal cancer, in an attempt to increase early diagnosis. The aim of this study was to evaluate the compliance of referrals received via the (2WW) pathway for suspected lower gastrointestinal cancer.

Method

We conducted a retrospective study which utilised a local cancer registry to identify all patients who had been referred to United Lincolnshire Hospitals Trust over a two-month period. Electronic patient records were checked to establish whether patients fulfilled the 2015 referral criteria.

Results

Out of 615 patients referred, 51 (8%) had colorectal cancer. 92 (15%) referrals did not meet the criteria for the 2WW pathway. Whether or not the referral was ‘appropriate’ had no significant effect on the diagnoses of bowel cancer (X2 = .003, p&gt;.05).

Conclusions

16% of all referrals did not meet criteria. This may appear as an inefficient use of resources, however there was no difference in rates of cancer between appropriate and inappropriate referrals. The referral criteria are likely to evolve over the course of time, and perhaps clinicians’ judgement should be taken into account.

Targeting cancer cell kinase PERK incites antitumor immunity by inducing immunogenic cell death and reprograming tumor-linked immunosuppressive myelopoiesis

The tumor microenvironment incites sustained endoplasmic reticulum (ER) stress in infiltrating T and myeloid cells, which impairs their antitumor potential through intrinsic activation of PKR-like endoplasmic reticulum kinase (PERK). Nonetheless, the immunomodulatory role of PERK activation in the tumor cell compartment remains unknown. Using multiple melanoma models, we established that PERK ablation (PERKKO) in cancer cells culminates in caspase-independent immunogenic cell death (ICD) in response to ER stress. In vivo, PERKKO cells underwent ICD and released immunostimulatory factors including HMGB1, ATP, calreticulin and type I interferons which provoked a dramatic anti-tumor response and induction of the abscopal effect. Immunologically, PERKKO tumor cells undergoing ICD spurred influx of CCR2-dependent monocyte-derived dendritic cells (MoDCs) and tumor infiltration of activated antigen-specific T cells. Moreover, PERK deletion in tumor cells triggered systemic expansion of myeloid precursors and promoted their differentiation into MoDCs via type I interferon signaling. Notably, MoDC-induced T cell responses in PERKKO tumors impaired B16-F10 tumor progression and enabled complete rejection of BrafV600E-SM1 tumors. Substantiating the translational potential of our work, inhibition of PERK in melanoma-bearing hosts resulted in significant anti-tumor effects. Also, TCGA analyses of melanoma patients showed that PERK signaling or repressed ICD marker expression coincided with shorter overall survival. Collectively, these results demonstrate that targeting PERK in tumor cells can offer the dual benefit of inducing ICD and reprogramming myelopoiesis to drive protective antitumor immunity.

COVID-19 in forensic psychiatry settings: The unique vulnerability of patients in secure services

Introduction

Secure forensic mental health services treat patient with high rates of treatment resistant psychoses, typically schizophrenia. These groups have high rates of obesity and medical co-morbidities. Population based studies have identified high risk groups in the event of SARS-CoV-2 infection, including those with long term medical conditions.

Objectives

The aim of this study was to compare the vulnerability to serious adverse outcome in the event of COVID-19 infection in a forensic psychiatric patient population.

Methods

All patients of a complete National Forensic Mental Health Service (n=141) were rated for risk of adverse outcome in the event of SARS-CoV-2 infection, using two structured tools, the COVID-AGE tool and the COVID-Risk tool.

Results

Eighty-two patients (58.2%) met criteria for obesity, 32 had type II diabetes and 28 were hypertensive. Mean chronological age was 45.5 years (SD 11.4, median 44.1), while mean COVID-AGE was 59.1 years (SD 19.4, median 58.0), mean difference 13.6 years (SD 15.6) paired t=10.9, df=140, p=0.000. Three patients (2.1%) were chronologically over 70 years compared to 40 (28.4%) with a COVID-AGE over 70 (X2=6.99, df=1, p=0.008, Fishers exact test p=0.027).

Conclusions

These risk assessments may identify the extent of increased risk among a uniquely medically vulnerable patient group. Patients in secure forensic psychiatric services represent a high-risk group for adverse outcomes in the event of SARS-COV-2 infection. Population based cocooning and self-isolating guidance based on chronological age may not be sufficient. There is an urgent need for better physical health research and treatment in this group.

Targeted Therapy Given after Anti-PD-1 Leads to Prolonged Responses in Mouse Melanoma Models through Sustained Antitumor Immunity

Immunotherapy (IT) and targeted therapy (TT) are both effective against melanoma, but their combination is frequently toxic. Here, we investigated whether the sequence of IT (anti-PD-1)→ TT (ceritinib-trametinib or dabrafenib-trametinib) was associated with improved antitumor responses in mouse models of BRAF- and NRAS-mutant melanoma. Mice with NRAS-mutant (SW1) or BRAF-mutant (SM1) mouse melanomas were treated with either IT, TT, or the sequence of IT→TT. Tumor volumes were measured, and samples from the NRAS-mutant melanomas were collected for immune-cell analysis, single-cell RNA sequencing (scRNA-seq), and reverse phase protein analysis (RPPA). scRNA-seq demonstrated that the IT→TT sequence modulated the immune environment, leading to increased infiltration of T cells, monocytes, dendritic cells and natural killer cells, and decreased numbers of tumor-associated macrophages, myeloid-derived suppressor cells, and regulatory T cells. Durable responses to the IT→TT sequence were dependent on T-cell activity, with depletion of CD8⁺, but not CD4⁺, T cells abrogating the therapeutic response. An analysis of transcriptional heterogeneity in the melanoma compartment showed the sequence of IT→TT enriched for a population of melanoma cells with increased expression of MHC class I and melanoma antigens. RPPA analysis demonstrated that the sustained immune response induced by IT→TT suppressed tumor-intrinsic signaling pathways required for therapeutic escape. These studies establish that upfront IT improves the responses to TT in BRAF- and NRAS-mutant melanoma models.

Prevalence and management of diabetes among the uninsured: A multicenter study in Tampa Bay, FL

AIMS

This study describes the prevalence and management of uninsured patients with diabetes in free clinics around the Tampa Bay area.

METHODS

A retrospective chart review collected data from uninsured patients who visited nine free clinics from January 2016 to December 2017. The data included sociodemographics, chronic disease diagnoses and treatments, and social history. Statistical analysis including chi-square tests and logistic regression were used to describe patients with diabetes.

RESULTS

With a prevalence of 19.41% among 6815 uninsured patients and a mean HbA1c of 7.9% (63 mmol/mol), patients with diabetes were more likely to be White, women, obese, unemployed, and have hypertension and depression compared to patients without diabetes. There were no significant differences in sociodemographic variables between those with controlled and uncontrolled diabetes. Among the variables studied by logistic regression, unemployment was found to be a significant predictor of poor glycemic control among men.

CONCLUSIONS

Diabetes is a challenging chronic disease among the uninsured of Tampa Bay due to its prevalence and suboptimal glycemic control. Obesity and unemployment represent significant challenges that increase the burden of diabetes among the uninsured. Free clinics may benefit from additional resources and intervention programs, with future research assessing their effects on care outcomes.

The Unfolded Protein Response Mediator PERK Governs Myeloid Cell-Driven Immunosuppression in Tumors through Inhibition of STING Signaling

The primary mechanisms supporting immunoregulatory polarization of myeloid cells upon infiltration into tumors remain largely unexplored. Elucidation of these signals could enable better strategies to restore protective anti-tumor immunity. Here, we investigated the role of the intrinsic activation of the PKR-like endoplasmic reticulum (ER) kinase (PERK) in the immunoinhibitory actions of tumor-associated myeloid-derived suppressor cells (tumor-MDSCs). PERK signaling increased in tumor-MDSCs, and its deletion transformed MDSCs into myeloid cells that activated CD8⁺ T cell-mediated immunity against cancer. Tumor-MDSCs lacking PERK exhibited disrupted NRF2-driven antioxidant capacity and impaired mitochondrial respiratory homeostasis. Moreover, reduced NRF2 signaling in PERK-deficient MDSCs elicited cytosolic mitochondrial DNA elevation and, consequently, STING-dependent expression of anti-tumor type I interferon. Reactivation of NRF2 signaling, conditional deletion of STING, or blockade of type I interferon receptor I restored the immunoinhibitory potential of PERK-ablated MDSCs. Our findings demonstrate the pivotal role of PERK in tumor-MDSC functionality and unveil strategies to reprogram immunosuppressive myelopoiesis in tumors to boost cancer immunotherapy.

Co-treatments to Boost IDO Activity and Inhibit Production of Downstream Catabolites Induce Durable Suppression of Experimental Autoimmune Encephalomyelitis

Reinforcing defective tolerogenic processes slows progression of autoimmune (AI) diseases and has potential to promote drug-free disease remission. Previously, we reported that DNA nanoparticles (DNPs) and cyclic dinucleotides (CDNs) slow progression of experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis, by activating the Stimulator of Interferon Genes (STING) signaling adaptor to stimulate interferon type 1 (IFN-I) production, which induced dendritic cells to express indoleamine 2,3 dioxygenase (IDO) and acquire immune regulatory phenotypes. Here, we show that therapeutic responses to DNPs depend on DNA sensing via cyclic GAMP synthase (cGAS) and interactions between Programmed Death-1 (PD-1) and PD-1 ligands. To investigate how increased tryptophan (Trp) metabolism by IDO promotes therapeutic responses mice were co-treated at EAE onset with DNPs and drugs that inhibit kynurenine aminotransferase-II (KatII) or 3-hydroxyanthranilic acid dioxygenase (HAAO) activity downstream of IDO in the kynurenine (Kyn) pathway. DNP and KatII or HAAO inhibitor co-treatments suppressed EAE progression more effectively than DNPs, while KatII inhibition had no significant therapeutic benefit and HAAO inhibition attenuated but did not prevent EAE progression. Moreover, therapeutic responses to co-treatments were durable as EAE progression did not resume after co-treatment. Thus, using STING agonists to boost IDO activity and manipulating the Kyn pathway downstream of IDO is an effective strategy to enhance tolerogenic responses that overcome autoimmunity to suppress EAE progression.

Expression of cancer cell-associated Protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK) regulates protective anti-tumor immunity in melanoma

Activation of moderated endoplasmic reticulum (ER) stress in cancer cells promotes cellular adaptation and survival in response to the adverse conditions of the tumor microenvironment (TME). However, how modulation of ER stress in cancer cells culminates in the development of an immunosuppressive TME remains poorly understood and therapeutically unexploited. Upon disruption of ER homeostasis, mediator proteins IRE1a, ATF6 and PERK induce activation of the unfolded protein response (UPR). Although maladaptive priming of UPR mediators in immune cells deactivates their capacity for anti-tumor immunity, the immunosuppressive potential of UPR mediators in cancer cells, in particular PERK, remains unknown. Thus, in this study, we hypothesized that activation of PERK in tumor cells shapes the formation of the immunosuppressive TME and impairs the development of anti-tumor immunity. Elimination of PERK in cancer cells impaired survival upon chemically-induced ER stress and promoted caspase-independent cell death. Interestingly, in vivo ablation of PERK in melanoma impaired tumor growth, which surprisingly occurred in a T cell-dependent manner. Additionally we observed that ablation of PERK shifted the TME from an immunosuppressive to immunostimulatory environment, enhanced accumulation of effector T cells and directed reprogramming of myeloid derived suppressor cells (MDSCs) into immunostimulatory cells. Additional experiments indicated that ablation of PERK induced expression of mediators associated with immunogenic cell death. Collectively, our findings demonstrate the immunoregulatory role of PERK in tumor cells and highlight the therapeutic potential of targeting UPR mediators and tumor adaptive processes.

Stimulator of interferon genes agonists attenuate type I diabetes progression in NOD mice

Reagents that activate the signaling adaptor stimulator of interferon genes (STING) suppress experimentally induced autoimmunity in murine models of multiple sclerosis and arthritis. In this study, we evaluated STING agonists as potential reagents to inhibit spontaneous autoimmune type I diabetes (T1D) onset in non-obese diabetic (NOD) female mice. Treatments with DNA nanoparticles (DNPs), which activate STING when cargo DNA is sensed, delayed T1D onset and reduced T1D incidence when administered before T1D onset. DNP treatment elevated indoleamine 2,3 dioxygenase (IDO) activity, which regulates T-cell immunity, in spleen, pancreatic lymph nodes and pancreas of NOD mice. Therapeutic responses to DNPs were partially reversed by inhibiting IDO and DNP treatment synergized with insulin therapy to further delay T1D onset and reduce T1D incidence. Treating pre-diabetic NOD mice with cyclic guanyl-adenyl dinucleotide (cGAMP) to activate STING directly delayed T1D onset and stimulated interferon-αβ (IFN-αβ), while treatment with cyclic diguanyl nucleotide (cdiGMP) did not delay T1D onset or induce IFN-αβ in NOD mice. DNA sequence analyses revealed that NOD mice possess a STING polymorphism that may explain differential responses to cGAMP and cdiGMP. In summary, STING agonists attenuate T1D progression and DNPs enhance therapeutic responses to insulin therapy.

Polyphenol-rich extract induces apoptosis with immunogenic markers in melanoma cells through the ER stress-associated kinase PERK

Polyphenols elicit antitumor activities, in part, through the induction of anti- or pro-oxidant effects in cancer cells which promote priming of protective anti-tumor immunity. We recently characterized a polyphenol-rich extract from Caesalpinia spinosa (P2Et) that stimulates in vivo antitumor responses against breast and melanoma tumor models via the promotion of immunogenic cancer cell death (ICD). However, the primary mediators whereby P2Et promotes ICD remained unknown. Here, we sought to elucidate the role that severe endoplasmic reticulum (ER) stress plays in mediating P2Et-induced apoptosis and ICD in murine melanoma cells. Our findings demonstrate a substantial selective induction of specific ER-stress mediators in B16-F10 melanoma cells treated with P2Et. While knockout of the ER stress-associated PKR-like ER kinase (PERK) prevented induction of apoptosis and expression of ICD markers in P2Et-treated cells, deletion of X-box binding protein 1 (Xbp1) did not. P2Et-driven activation of PERK in melanoma cells was found to promote ER-calcium release, disrupt mitochondrial membrane potential, and trigger upregulation of ICD drivers, surface calreticulin expression, and extracellular release of ATP and HMGB1. Notably, calcium release inhibition, but not targeting of PERK-driven integrated stress responses, prevented P2Et-induced apoptosis. Collectively, these results underline the central role of PERK-directed calcium release in mediating the antitumor and immunogenic actions of P2Et in melanoma cells.

AMPK Alpha-1 Intrinsically Regulates the Function and Differentiation of Tumor Myeloid-Derived Suppressor Cells

Myeloid-derived suppressor cells (MDSC) represent a primary mechanism of immune evasion in tumors and have emerged as a major obstacle for cancer immunotherapy. The immunoinhibitory activity of MDSC is tightly regulated by the tumor microenvironment and occurs through mechanistic mediators that remain unclear. Here, we elucidated the intrinsic interaction between the expression of AMP-activated protein kinase alpha (AMPKα) and the immunoregulatory activity of MDSC in tumors. AMPKα signaling was increased in tumor-MDSC from tumor-bearing mice and patients with ovarian cancer. Transcription of the Ampkα1-coding gene, Prkaa1, in tumor-MDSC was induced by cancer cell-derived granulocyte-monocyte colony-stimulating factor (GM-CSF) and occurred in a Stat5-dependent manner. Conditional deletion of Prkaa1 in myeloid cells, or therapeutic inhibition of Ampkα in tumor-bearing mice, delayed tumor growth, inhibited the immunosuppressive potential of MDSC, triggered antitumor CD8⁺ T-cell immunity, and boosted the efficacy of T-cell immunotherapy. Complementarily, therapeutic stimulation of AMPKα signaling intrinsically promoted MDSC immunoregulatory activity. In addition, Prkaa1 deletion antagonized the differentiation of monocytic-MDSC (M-MDSC) to macrophages and re-routed M-MDSC, but not granulocytic-MDSC (PMN-MDSC), into cells that elicited direct antitumor cytotoxic effects through nitric oxide synthase 2-mediated actions. Thus, our results demonstrate the primary role of AMPKα1 in the immunosuppressive effects induced by tumor-MDSC and support the therapeutic use of AMPK inhibitors to overcome MDSC-induced T-cell dysfunction in cancer. SIGNIFICANCE: AMPKα1 regulates the immunosuppressive activity and differentiation of tumor-MDSC, suggesting AMPK inhibition as a potential therapeutic strategy to restore protective myelopoiesis in cancer.

Deletion of Arginase 2 Ameliorates Retinal Neurodegeneration in a Mouse Model of Multiple Sclerosis

Optic neuritis is a major clinical feature of multiple sclerosis (MS) and can lead to temporary or permanent vision loss. Previous studies from our laboratory have demonstrated the critical involvement of arginase 2 (A2) in retinal neurodegeneration in models of ischemic retinopathy. The current study was undertaken to investigate the role of A2 in MS-mediated retinal neuronal damage and degeneration. Experimental autoimmune encephalomyelitis (EAE) was induced in wild-type (WT) and A2 knockout (A2^-/-) mice. EAE-induced motor deficits, loss of retinal ganglion cells, retinal thinning, inflammatory signaling, and glial activation were studied in EAE-treated WT and A2^-/- mice and their respective controls. Increased expression of A2 was observed in WT retinas in response to EAE induction. EAE-induced motor deficits were markedly reduced in A2^-/- mice compared with WT controls. Retinal flat mount studies demonstrated a significant reduction in the number of RGCs in WT EAE retinas in comparison with normal control mice. A significant improvement in neuronal survival was evident in retinas of EAE-induced A2^-/- mice compared with WT. RNA levels of the proinflammatory molecules CCL2, COX2, IL-1α, and IL-12α were significantly reduced in the A2^-/- EAE retinas compared with WT EAE. EAE-induced activation of glia (microglia and Müller cells) was markedly reduced in A2^-/- retinas compared with WT. Western blot analyses showed increased levels of phospho-ERK1/2 and reduced levels of phospho-BAD in the WT EAE retina, while these changes were prevented in A2^-/- mice. In conclusion, our studies establish EAE as an excellent model to study MS-mediated retinal neuronal damage and suggest the potential value of targeting A2 as a therapy to prevent MS-mediated retinal neuronal injury.

Adverse effects of energy drink on rat pancreas and the therapeutic role of each of bone marrow mesenchymal stem cells and Nigella Sativa oil

BACKGROUND

Energy drinks have been observed to threaten public health leading to many medical problems. Bone marrow-derived mesenchymal stem cells (BMSCs) have broad prospects in tissue regeneration. Nigella Sativa (NS) possess great therapeutic properties for the treatment of a wide range of diseases.

MATERIALS AND METHODS

Forty adult male albino rats were divided into: control group and treated group. The treated group was further subdivided into: energy drink subgroup 2a, BMSCs-injected subgroup 2b, NS-injected subgroup 2c. Histological, immunohistochemical and biochemical assessment was performed.

RESULTS

Administration of energy drink revealed that it adversely affected the pancreatic cytoarchitecture. BMSCs and NS have been similarly observed to significantly ameliorate the histological, biochemical and immunohistochemical changes induced by energy drink.

CONCLUSIONS

The extent of pancreatic regeneration, exerted by each of BMSCs and NS oil, is nearly similar but the effect of BMSCs is more superior; however, NS could be privileged to BMSCs as a line of treatment being easily accessible and of lower cost.

Abstract 3275: Inhibition of ER-stress factor C/EBP homologous protein (Chop) with LNAplus™ antisense-oligonucleotides to improve immunotherapy of cancer

The microenvironment generated by tumor cells and suppressive stromal cells creates unfavorable conditions for effector immune cells in order to escape anti-tumor immunity. Besides suppressive pathways like for example the CD39/CD73 axis, mechanisms including nutrient starvation, hypoxia, exposure to high levels of reactive oxygen species and acidosis contribute to the suppression of tumor-reactive immune cells. We have recently discovered that the ER-stress response, in particular the C/EBP homologous protein (Chop) plays an important role in the suppression of tumor-exposed T cells. Furthermore, it is upregulated in activated T cells in vitro and may hamper the efficacy of adoptive T cell therapies. As Chop is a transcription factor it falls into the category of “difficult to drug” and therefore represents an optimal target for antisense-oligonucleotides. In order to revert Chop-induced suppression of T cell activity, we designed locked nucleic acid (LNA) ASOs with specificity for mouse or human Chop using our Oligofyer™ bioinformatics system. Knockdown on mRNA level was investigated in cancer cell lines and in T cells in vitro and the most potent ASOs were selected for further experiments. Downstream effects of Chop knockdown were investigated by mRNA expression analysis and flow cytometry. We furthermore investigated the effect of ex vivo Chop knockdown on the efficacy of adoptively transferred Pmel-specific T cells (recognized target: gp10025-33 peptide) in a B16 melanoma model. Treatment of cells with selected Chop-specific ASO leads to potent knockdown of Chop in vitro. In accordance with observations made in T cells derived from Chop-knockout mice, we observed an increase in T cell-associated transcription factor (Tbet), Interferon-gamma (IFN-γ) and Granzyme B (GZMB) expression in T cells that have been treated with a Chop ASO compared to control oligo treated cells. Strikingly, this translated into improved tumor control by Pmel-specific T cells. We furthermore observed an increase in IFN-γ producing tumor-infiltrating T cells and increased frequency of IFN-γ producing T cells in gp100 restimulated splenocytes from animals that received Chop ASO-treated Pmel-specific T cells. Of note, the impact of Chop knockdown was comparable to the effects that we observed in T cells derived from Chop knockout animals. Taken together, we herein show that Chop is a highly promising novel target in immunotherapy and can effectively be targeted by LNAplus™ ASOs. As shown in a model of adoptive T cell therapy, Chop ASOs have a high potential to optimize the efficacy of T cell therapies, such as chimeric antigen receptor (CAR)- or T cell receptor (TCR)-transgenic T cells. We are currently investigating the effect of systemic Chop ASO treatment in murine tumor models to expand the spectrum of applications of this innovative therapeutic tool.

Citation Format: Richard Klar, Yu Cao, Eslam Mohamed, Sven Michel, Monika Schell, Lisa Hinterwimmer, Stefanie Raith, Paulo Rodriguez, Frank Jaschinski. Inhibition of ER-stress factor C/EBP homologous protein (Chop) with LNAplus™ antisense-oligonucleotides to improve immunotherapy of cancer [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 3275.

Regulation of indoleamine 2,3 dioxygenase and its role in a porcine model of acute kidney allograft rejection

In kidney transplantation acute allograft rejection is the most common cause of late allograft loss. Changes in indoleamine 2,3 dioxygenase (IDO) activity, which catabolizes the degradation of tryptophan to kynurenine, may predict rejection. However, exogenous IDO is immunosuppressive in rodent kidney transplantation. Thus, the increase in IDO activity observed in acute allograft rejection is insufficient to prevent rejection. To address this question, we assessed the regulation of IDO and its role in acute rejection in a porcine model of kidney transplant. In tissue samples from rejecting kidney allografts, we showed a 13-fold increase in IDO gene transcription and 20-fold increase in IDO enzyme activity when compared with autotransplanted kidneys. Allografts also demonstrated an over fourfold increase in tissue interferon (IFN)-γ, with marked increases in tumor necrosis factor (TNF)-α, TNF-β and interleukin 1β. Gene transcription and protein levels of kynurenine 3-monooxygenase (KMO) were decreased. KMO generates the immunosuppressive kynurenine, 3-hydroxykynurenine. The results of these studies demonstrate a clear association between rejection and increased allograft IDO expression, likely driven in part by IFN-γ and facilitated by other cytokines of the allogeneic response. Moreover, the loss of downstream enzymatic activity in the IDO metabolic pathway may suggest novel mechanisms for the perpetuation of rejection.

Outcome of indeterminate liver lesions on computed tomography in patients with colorectal cancer

Introduction The aim of this study was to determinate the outcome of indeterminate liver lesions on computed tomography (CT) in patients with a background history of colorectal cancer (CRC) and to identify clinicopathological variables associated with malignancy in these lesions. A secondary aim was to devise a management algorithm for such patients. Methods Patients referred to our institution with indeterminate liver lesions on CT with a background history of CRC between January 2012 and December 2014 were included in the study. Clinicopathological factors, surveillance period and histological findings were analysed. Results Fifty-six patients with indeterminate liver lesions were identified. Fifty-three (94.6%) of these required further imaging (magnetic resonance imaging [MRI; n=50] and positron emission tomography combined with CT [n=3]). For the patients who had MRI, the underlying diagnosis was benign in 19 and colorectal liver metastasis (CRLM) in 8 while 23 patients and an indeterminate lesion. In cases that remained indeterminate following MRI, liver resection was performed in 2 patients for a high suspicion of CRLM while the 21 remaining patients underwent interval surveillance (median: 9 months, range: 3-52 months). Of these 21 patients, 14 had benign lesions while CRLM was noted in 6 patients and an incidental hepatocellular carcinoma in a single patient. Age ≥65 years was the only statistically significant clinicopathological factor in predicting an underlying malignancy in patients with indeterminate liver lesions on CT. Conclusions Over a third of the patients diagnosed with indeterminate liver lesions on CT subsequently showed evidence of CRLM. These indeterminate lesions are more likely to be malignant in patients aged ≥65 years.

The cellular metabolic landscape in the tumor milieu regulates the activity of myeloid infiltrates

Malignant cells upregulate distinct energy metabolism programs that support their proliferation, migration, and adaptation to the stressful tumor microenvironment (TME). Additionally, this exaggerated metabolic activity allows cancer cells to hijack essential nutrients and outcompete neighboring infiltrating immune cells, thereby impairing antitumor immunity. During recent years, there has been great interest in the field to understand the tumor-induced energy metabolism signals that regulate the function of immune cells in individuals with cancer. Accordingly, it is now well accepted that uncovering the mechanisms that instruct the metabolic behavior of cancer cells and tumor-associated immune cells is an indispensable strategy for the development of new approaches to overcome immune suppression in tumors. Thus, in this minireview, we briefly discuss the interaction between particular metabolic signaling pathways and immunosuppressive activity in different subsets of myeloid cells within the TME. Additionally, we illustrate potential central mechanisms controlling the metabolic reprogramming of myeloid cells in response to tumor-derived factors.

Antigen-Specific Antitumor Responses Induced by OX40 Agonist Are Enhanced by the IDO Inhibitor Indoximod

Although an immune response to tumors may be generated using vaccines, so far, this approach has only shown minimal clinical success. This is attributed to the tendency of cancer to escape immune surveillance via multiple immune suppressive mechanisms. Successful cancer immunotherapy requires targeting these inhibitory mechanisms along with enhancement of antigen-specific immune responses to promote sustained tumor-specific immunity. Here, we evaluated the effect of indoximod, an inhibitor of the immunosuppressive indoleamine-(2,3)-dioxygenase (IDO) pathway, on antitumor efficacy of anti-OX40 agonist in the context of vaccine in the IDO^- TC-1 tumor model. We demonstrate that although the addition of anti-OX40 to the vaccine moderately enhances therapeutic efficacy, incorporation of indoximod into this treatment leads to enhanced tumor regression and cure of established tumors in 60% of treated mice. We show that the mechanisms by which the IDO inhibitor leads to this therapeutic potency include (i) an increment of vaccine-induced tumor-infiltrating effector T cells that is facilitated by anti-OX40 and (ii) a decrease of IDO enzyme activity produced by nontumor cells within the tumor microenvironment that results in enhancement of the specificity and the functionality of vaccine-induced effector T cells. Our findings suggest a translatable strategy to enhance the overall efficacy of cancer immunotherapy. Cancer Immunol Res; 6(2); 201-8. ©2018 AACR.

Anti-Jagged Immunotherapy Inhibits MDSCs and Overcomes Tumor-Induced Tolerance

Myeloid-derived suppressor cells (MDSC) are a major obstacle to promising forms of cancer immunotherapy, but tools to broadly limit their immunoregulatory effects remain lacking. In this study, we assessed the therapeutic effect of the humanized anti-Jagged1/2-blocking antibody CTX014 on MDSC-mediated T-cell suppression in tumor-bearing mice. CTX014 decreased tumor growth, affected the accumulation and tolerogenic activity of MDSCs in tumors, and inhibited the expression of immunosuppressive factors arginase I and iNOS. Consequently, anti-Jagged therapy overcame tumor-induced T-cell tolerance, increased the infiltration of reactive CD8⁺ T cells into tumors, and enhanced the efficacy of T-cell-based immunotherapy. Depletion of MDSC-like cells restored tumor growth in mice treated with anti-Jagged, whereas coinjection of MDSC-like cells from anti-Jagged-treated mice with cancer cells delayed tumor growth. Jagged1/2 was induced in MDSCs by tumor-derived factors via NFkB-p65 signaling, and conditional deletion of NFkB-p65 blocked MDSC function. Collectively, our results offer a preclinical proof of concept for the use of anti-Jagged1/2 to reprogram MDSC-mediated T-cell suppression in tumors, with implications to broadly improve the efficacy of cancer therapy. Cancer Res; 77(20); 5628-38. ©2017 AACR.

The front-line general surgery consultant as a new model of emergency care

Introduction Emergency general surgery services in England are undergoing rapid structural change with the aim of improving care. In our centre, the key issues identified were high numbers of admissions, inappropriate referrals, prolonged waiting times, delayed senior input and poor patient satisfaction. A new model was launched in January 2015 to address these issues: the surgical triage unit (STU). This study assesses the success of the new service. Methods All emergency general surgical admissions during a five-month period before introduction of the STU were compared with those of a comparable five-month period after its introduction. Process, clinical and patient experience outcomes were assessed to identify improvement. Results Attendance fell from 3,304 patients in the 2014 cohort to 2,830 in the 2015 cohort. During the 2015 study period, 279 more patients were discharged on the same day. Resource requirement fell by 2,635 bed days (23%). The number of true surgical emergencies remained consistent. Rates for reattendance (7.8% for 2014 vs 8.1% for 2015) and readmission (5.7% for 2014 vs 5.7% for 2015) showed no significant difference. Patient experience data demonstrated a significant improvement in both net promoter score (64.1 vs 82.2) and number of complaints (34 vs 5). Clinical outcomes for low risk procedures remained similar. Emergency laparotomy in-hospital mortality fell (11.4% vs 10.3%) despite preoperative risk stratification suggesting a risk burden that was significantly higher than the national average. Conclusions This novel model of emergency general surgery provision has improved clinical efficiency, patient satisfaction and outcomes. We encourage other units to consider similar programmes of service improvement.

Endoplasmic reticulum stress regulates tumor growth and anti-tumor immunity: a promising opportunity for cancer immunotherapy

The endoplasmic reticulum (ER) stress is a cellular process that occurs as a consequence of several stress circumstances, such as the accumulation of unfolded proteins in the lumen of the ER or distinct insults that disturb the ER normal function. Different conditions in the tumor microenvironment (TME), including hypoxia, nutrient deprivation, and the elevated production of reactive oxygen and nitrogen species destabilize the loading and dispatching of the newly synthesized proteins, triggering ER stress in cancer cells and tumor-infiltrating leukocytes. In order to cope with TME-induced ER stress, tumor and stromal cells initiate an adaptive response process that aims to resolve ER stress and to restore cellular homeostasis, which is referred as the unfolded protein responses (UPR). Paradoxically, the UPR can also induce cell death under severe and/or permanent ER stress. The UPR is started through three mediators, the activation of the inositol-requiring enzyme-1α, the pancreatic ER kinase-like ER kinase, and the activating transcription factor 6. In this minireview, we will discuss the pro- and anti-tumorigenic role of the UPR in cancer cells. In addition, we will describe the effects of the TME-induced ER stress in the immunosuppressive activity of tumor-infiltrating myeloid cells. Also, we will review the results of emerging therapeutic interventions that target ER stress and the UPR mediators in cancer. We postulate that the inhibition of ER stress or the UPR-related elements could represent a significant approach to increase the efficacy of various forms of cancer immunotherapy.

Unfolding anti-tumor immunity: ER stress responses sculpt tolerogenic myeloid cells in cancer

Established tumors build a stressful and hostile microenvironment that blocks the development of protective innate and adaptive immune responses. Different subsets of immunoregulatory myeloid populations, including dendritic cells, myeloid-derived suppressor cells (MDSCs) and macrophages, accumulate in the stressed tumor milieu and represent a major impediment to the success of various forms of cancer immunotherapy. Specific conditions and factors within tumor masses, including hypoxia, nutrient starvation, low pH, and increased levels of free radicals, provoke a state of “endoplasmic reticulum (ER) stress” in both malignant cells and infiltrating myeloid cells. In order to cope with ER stress, cancer cells and tumor-associated myeloid cells activate an integrated signaling pathway known as the Unfolded Protein Response (UPR), which promotes cell survival and adaptation under adverse environmental conditions. However, the UPR can also induce cell death under unresolved levels of ER stress. Three branches of the UPR have been described, including the activation of the inositol-requiring enzyme 1 (IRE1), the pancreatic ER kinase (PKR)-like ER kinase (PERK), and the activating transcription factor 6 (ATF6). In this minireview, we briefly discuss the role of ER stress and specific UPR mediators in tumor development, growth and metastasis. In addition, we describe how sustained ER stress responses operate as key mediators of chronic inflammation and immune suppression within tumors. Finally, we discuss multiple pharmacological approaches that overcome the immunosuppressive effect of the UPR in tumors, and that could potentially enhance the efficacy of cancer immunotherapies by reprogramming the function of tumor-infiltrating myeloid cells.

Virus Infections Incite Pain Hypersensitivity by Inducing Indoleamine 2,3 Dioxygenase

Increased pain sensitivity is a comorbidity associated with many clinical diseases, though the underlying causes are poorly understood. Recently, chronic pain hypersensitivity in rodents treated to induce chronic inflammation in peripheral tissues was linked to enhanced tryptophan catabolism in brain mediated by indoleamine 2,3 dioxygenase (IDO). Here we show that acute influenza A virus (IAV) and chronic murine leukemia retrovirus (MuLV) infections, which stimulate robust IDO expression in lungs and lymphoid tissues, induced acute or chronic pain hypersensitivity, respectively. In contrast, virus-induced pain hypersensitivity did not manifest in mice lacking intact IDO1 genes. Spleen IDO activity increased markedly as MuLV infections progressed, while IDO1 expression was not elevated significantly in brain or spinal cord (CNS) tissues. Moreover, kynurenine (Kyn), a tryptophan catabolite made by cells expressing IDO, incited pain hypersensitivity in uninfected IDO1-deficient mice and Kyn potentiated pain hypersensitivity due to MuLV infection. MuLV infection stimulated selective IDO expression by a discreet population of spleen cells expressing both B cell (CD19) and dendritic cell (CD11c) markers (CD19⁺ DCs). CD19⁺ DCs were more susceptible to MuLV infection than B cells or conventional (CD19^neg) DCs, proliferated faster than B cells from early stages of MuLV infection and exhibited mature antigen presenting cell (APC) phenotypes, unlike conventional (CD19^neg) DCs. Moreover, interactions with CD4 T cells were necessary to sustain functional IDO expression by CD19⁺ DCs in vitro and in vivo. Splenocytes from MuLV-infected IDO1-sufficient mice induced pain hypersensitivity in uninfected IDO1-deficient recipient mice, while selective in vivo depletion of DCs alleviated pain hypersensitivity in MuLV-infected IDO1-sufficient mice and led to rapid reduction in splenomegaly, a hallmark of MuLV immune pathogenesis. These findings reveal critical roles for CD19⁺ DCs expressing IDO in host responses to MuLV infection that enhance pain hypersensitivity and cause immune pathology. Collectively, our findings support the hypothesis elevated IDO activity in non-CNS due to virus infections causes pain hypersensitivity mediated by Kyn. Previously unappreciated links between host immune responses to virus infections and pain sensitivity suggest that IDO inhibitors may alleviate heightened pain sensitivity during infections.

Chronic pain is a factor in diseases that afflict many people, yet the underlying causes of pain are poorly understood. Here we assess the effects of virus infections on pain sensitivity in mice. Infecting mice with two different viruses, influenza and mouse leukemia virus (MuLV) increased pain sensitivity. Influenza infection caused transient increase in pain sensitivity, which returned to normal levels after infections were cleared. However persistent MuLV infections caused sustained increase in pain sensitivity. Virus-induced pain sensitivity was reduced substantially in mice lacking the enzyme indoleamine 2,3 dioxygenase (IDO), which degrades the amino acid tryptophan. Moreover a natural compound produced by cells expressing IDO enhanced pain sensitivity when administered to mice lacking IDO genes. Thus cells expressing IDO caused increased pain sensitivity in infected mice. A distinctive cell type expressed IDO selectively and accumulated in spleens of MuLV-infected mice. Transfer of spleen cells from MuLV-infected mice caused increased pain sensitivity in uninfected mice while eliminating specific cells in MuLV-infected mice abolished enhanced pain sensitivity. Our findings show that host immune responses to virus infections cause increased pain sensitivity and suggest novel ways to alleviate pain during infections.

DNA sensing via STING regulates immune responses in a lung cancer model via IDO

The Stimulator of Interferon Genes (STING) is a signaling adaptor associated with the endoplasmic reticulum. STING is activated by cytosolic DNA sensors to stimulate IFN type I expression (IFN-I). Recent reports revealed that DNA sensing to activate STING in dendritic cells (DCs) that engulfed dying tumor cells impeded growth of immunogenic tumors and potentiated responses to therapy. Consistent with these findings, synthetic STING agonists enhanced tumor regression. Paradoxically, Lewis Lung Carcinoma (LLC) grew slower in STING-deficient mice, revealing that STING is required for optimal LLC growth. Mechanistically, STING ablation abolished upregulation of the immunoregulatory enzyme, indoleamine 2,3 dioxygenase (IDO) in DCs located in tumor draining lymph nodes during LLC growth. Also, expression of the regulatory cytokine IL-10 and infiltration of myeloid derived suppressor cells (MDSCs) into the tumor microenvironment (TME) was diminished in mice lacking STING. In contrast, STING was not required for optimal growth of LLC tumors expressing neo-antigens, revealing a pivotal role for tumor antigenicity in influencing responses to DNA in the TME. These findings support the hypothesis that DNA from dying cells are sensed in the TME to activate STING, which induces dominant regulatory responses via IDO when tumor antigenicity is low and dominant immunogenic responses when tumor antigenicity is enhanced. Thus, cytosolic DNA sensing to activate STING has dichotomous roles in the TME, and tumor antigenicity is a pivotal factor influencing immune responses to DNA at sites of chronic inflammation associated with tumor growth.

STING Promotes the Growth of Tumors Characterized by Low Antigenicity via IDO Activation

Cytosolic DNA sensing is an important process during the innate immune response that activates the stimulator of interferon genes (STING) adaptor and induces IFN-I. STING incites spontaneous immunity during immunogenic tumor growth and accordingly, STING agonists induce regression of therapy-resistant tumors. However DNA, STING agonists, and apoptotic cells can also promote tolerogenic responses via STING by activating immunoregulatory mechanisms such as indoleamine 2,3 dioxygenase (IDO). Here, we show that IDO activity induced by STING activity in the tumor microenvironment (TME) promoted the growth of Lewis lung carcinoma (LLC). Although STING also induced IDO in tumor-draining lymph nodes (TDLN) during EL4 thymoma growth, this event was insufficient to promote tumorigenesis. In the LLC model, STING ablation enhanced CD8(+) T-cell infiltration and tumor cell killing while decreasing myeloid-derived suppressor cell infiltration and IL10 production in the TME. Depletion of CD8(+) T cells also eliminated the growth disadvantage of LLC tumors in STING-deficient mice, indicating that STING signaling attenuated CD8(+) T-cell effector functions during tumorigenesis. In contrast with native LLC tumors, STING signaling neither promoted growth of neoantigen-expressing LLC, nor did it induce IDO in TDLN. Similarly, STING failed to promote growth of B16 melanoma or to induce IDO activity in TDLN in this setting. Thus, our results show how STING-dependent DNA sensing can enhance tolerogenic states in tumors characterized by low antigenicity and how IDO inhibition can overcome this state by attenuating tumor tolerance. Furthermore, our results reveal a greater complexity in the role of STING signaling in cancer, underscoring how innate immune pathways in the TME modify tumorigenesis in distinct tumor settings, with implications for designing effective immunotherapy trials. Cancer Res; 76(8); 2076-81. ©2016 AACR.

Abstract 698: CPI-based Crizotinib systemic study on discovery of phenotypic off-target

Crizotinib, a first ever ALK/MET multi-targeted receptor tyrosine kinase inhibitor for the treatment of ALK-rearranged NSCLC patients. We hypothesize that crizotinib acts on other molecular targets in addition to tyrosine kinases ALK/MET and may play critical role given that there is a complex network of kinases that work together to regulate a number of important cellular processes and different disease signature. Approaching with a comprehensive docking method with our established chemical-protein interactome (CPI) and crizotinib, we have discovered 301 PDB-deposited proteins corresponding to 353 ligand binding pockets among a total of 1,780 PDB-deposited human protein entries. Systemic pharmacology approach also applied including validation the molecular target(s) of TKIs in vitro. Especially multiple human cellular models (including NSCLC and melanoma) and signaling study, luc-reporter, autophagy/apoptosis, proteomics study and NGS analysis applied. Interestingly, crizotinib besides had a high CPI binding score (ZZ_score) of -2.2778 against tyrosine kinase Lck, also had -1.4672, -1.1242, -0.7033 and -1.5384 against MAPK3, S6K, GSK-3β and HDAC 7A, respectively, which indicated crizotinib had potential broad range interaction with both TK and ser/thr kinases. Our data have showed that the crizotinib induced autophagy by activated LC3 in vitro and inhibited oncogenic Akt/mTOR signaling in human multiple melanoma cells resulting in G2/M cell cycle arrest. Furthermore, crizotinib increased p21Waf1/cip1 and Foxo3A expression and tumor suppressor miR-146a in human melanoma cells. Taken together, crizotinib induces miR-146a, autophagy and p21waf1/cip1 may potentially treat other type of human cancer by concurrently targeting tyrosine kinase, Akt/mTOR/Foxo axis and nuclear receptor, shedding a light for future both anti-cancer and anti-metabolic disorder drug discovery and development. This is the first CPI-based systemic study on leading discovery of crizotinib off-target phenotypic importance. These findings suggest that non-tyrosine kinase target of crizotinib may play critical role(s) for drug repositioning may represent a new and effective approach to expanding the application of existing drugs.

Citation Format: Jiazhi Sun, Lun Yang, Minghua Li, Shimin Zhang, Ian E. Heller, Johnathan Samuelson, Steven Cindric, Kunal Mishra, Eslam Mohamed, Feng Cheng, Kevin B. Sneed, Lin He, Shu-Feng Zhou. CPI-based Crizotinib systemic study on discovery of phenotypic off-target. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 698. doi:10.1158/1538-7445.AM2015-698

B Cell-Intrinsic IDO1 Regulates Humoral Immunity to T Cell-Independent Antigens

Humoral responses to nonproteinaceous Ags (i.e., T cell independent [TI]) are a key component of the early response to bacterial and viral infection and a critical driver of systemic autoimmunity. However, mechanisms that regulate TI humoral immunity are poorly defined. In this study, we report that B cell-intrinsic induction of the tryptophan-catabolizing enzyme IDO1 is a key mechanism limiting TI Ab responses. When Ido1(-/-) mice were immunized with TI Ags, there was a significant increase in Ab titers and formation of extrafollicular Ab-secreting cells compared with controls. This effect was specific to TI Ags, as Ido1 disruption did not affect Ig production after immunization with protein Ags. The effect of IDO1 abrogation was confined to the B cell compartment, as adoptive transfer of Ido1(-/-) B cells to B cell-deficient mice was sufficient to replicate increased TI responses observed in Ido1(-/-) mice. Moreover, in vitro activation with TLR ligands or BCR crosslinking rapidly induced Ido1 expression and activity in purified B cells, and Ido1(-/-) B cells displayed enhanced proliferation and cell survival associated with increased Ig and cytokine production compared with wild-type B cells. Thus, our results demonstrate a novel, B cell-intrinsic, role for IDO1 as a regulator of humoral immunity that has implications for both vaccine design and prevention of autoimmunity.

DNA sensing via STING regulates autoimmunity and tumor immunity. (IRM5P.648)

The Stimulator of Interferon Genes (STING) is activated by cytosolic DNA sensors such as cyclic GMP-AMP Synthase (cGAS) to induce interferon type I (IFN-I). Dendritic cells (DCs) that engulf dying tumor cells incite anti-tumor T cell immunity by sensing tumor cell DNA to activate STING/IFN-I signaling. Paradoxically, we find that DNA sensing to activate STING/IFN-I signaling induces DCs to express indoleamine 2, 3 dioxygenase (IDO), which activates regulatory T cells (Tregs). Thus treatment with DNA nanoparticles (DNPs) or cyclic dinucleotides (CDNs) to activate STING attenuated Experimental Autoimmune Encephalomyelitis (EAE), arthritis, and therapeutic responses were dependent on STING/IFN-I signaling to induce IDO. DNP and CDN treatments were also effective in slowing Type I Diabetes (T1D) progression in susceptible female Non-Obese Diabetic (NOD) mice. STING ablation also abolished IDO-dependent regulatory responses to apoptotic cells, suggesting that DNA from dying cells is sensed to activate the STING/IFN-I pathway and induce IDO to suppress autoimmunity. Moreover, cGAS and STING ablation abolished the ability of Lewis Lung carcinoma (LLC) tumor cells to induce local IDO, which suppresses anti-tumor immunity. These findings support the hypothesis that DNA from dying cells is sensed to activate STING/IFN-I in regulatory DCs that suppress T cell immunity and autoimmunity at sites of chronic inflammation associated with autoimmunity and tumor growth.

Activation of the STING adaptor attenuates experimental autoimmune encephalitis

Cytosolic DNA sensing activates the stimulator of IFN genes (STING) adaptor to induce IFN type I (IFN-αβ) production. Constitutive DNA sensing to induce sustained STING activation incites tolerance breakdown, leading to autoimmunity. In this study, we show that systemic treatments with DNA nanoparticles (DNPs) induced potent immune regulatory responses via STING signaling that suppressed experimental autoimmune encephalitis (EAE) when administered to mice after immunization with myelin oligodendrocyte glycoprotein (MOG), at EAE onset, or at peak disease severity. DNP treatments attenuated infiltration of effector T cells into the CNS and suppressed innate and adaptive immune responses to myelin oligodendrocyte glycoprotein immunization in spleen. Therapeutic responses were not observed in mice treated with cargo DNA or cationic polymers alone, indicating that DNP uptake and cargo DNA sensing by cells with regulatory functions was essential for therapeutic responses to manifest. Intact STING and IFN-αβ receptor genes, but not IFN-γ receptor genes, were essential for therapeutic responses to DNPs to manifest. Treatments with cyclic diguanylate monophosphate to activate STING also delayed EAE onset and reduced disease severity. Therapeutic responses to DNPs were critically dependent on IDO enzyme activity in hematopoietic cells. Thus, DNPs and cyclic diguanylate monophosphate attenuate EAE by inducing dominant T cell regulatory responses via the STING/IFN-αβ/IDO pathway that suppress CNS-specific autoimmunity. These findings reveal dichotomous roles for the STING/IFN-αβ pathway in either stimulating or suppressing autoimmunity and identify STING-activating reagents as a novel class of immune modulatory drugs.

Activation of the stimulator of interferon genes (STING) adaptor attenuates experimental autoimmune encephalitis (THER6P.848)

Activation of Stimulator of Interferon genes (STING) adaptor causes the release of IFN αβ in most of the cells, an activity that is tightly controlled to avoid continuous immune activation that could lead to autoimmunity. Here we show that STING activators can be used systemically to suppress experimental autoimmune encephalitis following myelin oligodendrocyte (MOG) immunization through STING-IFN αβ pathway. DNA nanoparticles (DNPs) attenuated MOG-specific effector responses in CNS and spleen. Therapeutic responses to DNPs are dependent on STING adaptor and IFN αβ receptors as they were abolished in mice lacking those genes. Additionally, indoleamine 2,3 dioxygenase enzyme (IDO) is crucial for therapeutic responses to DNPs as the loss of IDO1 gene in hematopoietic cells and IDO inhibition by 1-methyl-D-tryptophan had ablated those responses. Cyclic diguanylate monophosphate (c-diGMP), a direct STING activator also attenuated EAE progression and disease severity. Thus, Systemic administration of DNPs and c-diGMP can attenuate EAE through STING-IFN αβ-IDO regulatory pathway that is activated in certain immune cells subsets to overcome CNS specific autoimmunity. These findings emphasize a previously unappreciated role of STING activators to attenuate autoimmunity.