Selective turn-on sensing of adenosine diphosphate and phosphate anions by ruthenium (II) polypyridine anchored p-tert-butylcalix[4]arene platform

BACKGROUND

Nucleoside polyphosphate (NPP) anions are important for enzymatic activity and should be monitored by scientists in industry and medicine. By elucidating enzyme kinetics and processes, it aids in the discovery of effective inhibitors and activators. Nucleoside polyphosphate (NPP) anions are used by kinases, GTPases, and glycosyltransferases (GTs). Phosphorylation of certain amino acid residues (Ser, Thr, and Tyr) on proteins requires the breakdown of ATP by protein kinases, which produces ADP. Protein kinases, breakdown of ATP, and NPP are the focus of oncology drug development because the aberrant control of kinase activity is a common cause of cancer.

RESULTS

However, a discriminative turn-on fluorescent property is exhibited by non-fluorescent p-tertbutylcalix[4]arene modified 1,2,3-triazole containing bis-ruthenium polypyridyl complex (RL) upon the addition of phosphate anions such as (dihydrogen pyrophosphate (H2P2O72-) and dihydrogen phosphate (H2PO4-)) in CH3CN solvent and Adenosine Diphosphate (ADP) in CH3CN/HEPES (pH = 7.4) buffer (9/1, v/v). The probe RL shows a better-recognizing ability with pyrophosphate anion (H2P2O72-) than dihydrogen phosphate anion (H2PO4-). With H2P2O72- and H2PO4- anions, the RL detection limit was calculated to be as low as 83 nM and 198 nM, respectively.

SIGNIFICANCE

The calix[4]arene macrocycle's excellent size and binding cone conformation make it a good host-guest interface for the pyrophosphate anion and ADP. The bis-ruthenium polypyridyl complex's connection to the p-tertbutyl calix[4]arene moiety creates the ADP selectivity turn-on sensor. When moving from mono-nuclear to bi-nuclear ruthenium complex anchored on p-tertbutyl calix[4]arene, the probe can differentiate ADP, ATP, and AMP. Furthermore, this platform is a great resource for creating devices to simultaneously assess phosphate anions in environmental samples.

--Eleven tips for operational researchers working with health programmes: our experience based on implementing differentiated tuberculosis care in south India

Due to the workload and lack of a critical mass of trained operational researchers within their ranks, health systems and programmes may not be able to dedicate sufficient time to conducting operational research (OR). Hence, they may need the technical support of operational researchers from research/academic organisations. Additionally, there is a knowledge gap regarding implementing differentiated tuberculosis (TB) care in programme settings. In this 'how we did it' paper, we share our experience of implementing a differentiated TB care model along with an inbuilt OR component in Tamil Nadu, a southern state in India. This was a health system initiative through a collaboration of the State TB cell with the Indian Council of Medical Research institutes and the World Health Organisation country office in India. The learnings are in the form of eleven tips: four broad principles (OR on priority areas and make it a health system initiative, implement simple and holistic ideas, embed OR within routine programme settings, aim for long-term engagement), four related to strategic planning (big team of investigators, joint leadership, decentralised decision-making, working in advance) and three about implementation planning (conducting pilots, smart use of e-tools and operational research publications at frequent intervals). These may act as a guide for other Indian states, high TB burden countries that want to implement differentiated care, and for operational researchers in providing technical assistance for strengthening implementation and conducting OR in health systems and programmes (TB or other health programmes). Following these tips may increase the chances of i) an enriching engagement, ii) policy/practice change, and iii) sustainable implementation.

Of mice and lymphoid aggregates: modeling tertiary lymphoid structures in cancer

Tertiary lymphoid structures (TLS) are lymph node-like aggregates that can form in association with chronic inflammation or cancer. Mature TLS are organized into B and T cell zones, and are not encapsulated but include all cell types necessary for eliciting an adaptive immune response. TLS have been observed in various cancer types and are generally associated with a positive prognosis as well as increased sensitivity to cancer immunotherapy. However, a comprehensive understanding of the roles of TLS in eliciting anti-tumor immunity as well as the mechanisms involved in their formation and function is still lacking. Further studies in orthotopic, immunocompetent cancer models are necessary to evaluate the influence of TLS on cancer therapies, and to develop new treatments that promote their formation in cancer. Here, we review key insights obtained from functional murine studies, discuss appropriate models that can be used to study cancer-associated TLS, and suggest guidelines on how to identify TLS and distinguish them from other antigen-presenting niches.

Single-Cell RNA Analysis Reveals Cell-Intrinsic Functions of CAR T Cells Correlating with Response in a Phase II Study of Lymphoma Patients

PURPOSE

Although CD19 chimeric antigen receptor T cells (CAR-T) therapy has shown remarkable success in B-cell malignancies, a substantial fraction of patients do not obtain a long-term clinical response. This could be influenced by the quality of the individual CAR-T infusion product. To shed some light on this, clinical outcome was correlated to characteristics of CAR-T infusion products.

PATIENTS AND METHODS

In this phase II study, patients with B-cell lymphoma (n = 23) or leukemia (n = 1) received one or two infusions of third-generation CD19-directed CAR-Ts (2 × 108/m2). The clinical trial was registered at clinicaltrials.gov: NCT03068416. We investigated the transcriptional profile of individual CD19 CAR-T infusion products using targeted single-cell RNA sequencing and multicolor flow cytometry.

RESULTS

Two CAR-T infusions were not better than one in the settings used in this study. As for the CAR-T infusion products, we found that effector-like CD8+CAR-Ts with a high polyfunctionality, high cytotoxic and cytokine production profile, and low dysfunctional signature were associated with clinical response. An extended ex vivo expansion time during CAR-T manufacturing negatively influenced the proportion of effector CD8+CAR-Ts in the infusion product.

CONCLUSIONS

We identified cell-intrinsic characteristics of effector CD8+CAR-Ts correlating with response that could be used as an indicator for clinical outcome. The results in the study also serve as a guide to CAR-T manufacturing practices.

Complementarity-determining region clustering may cause CAR-T cell dysfunction

Chimeric antigen receptor (CAR)-T cell therapy is rapidly advancing as cancer treatment, however, designing an optimal CAR remains challenging. A single-chain variable fragment (scFv) is generally used as CAR targeting moiety, wherein the complementarity-determining regions (CDRs) define its specificity. We report here that the CDR loops can cause CAR clustering, leading to antigen-independent tonic signalling and subsequent CAR-T cell dysfunction. We show via CARs incorporating scFvs with identical framework and varying CDR sequences that CARs may cluster on the T cell surface, which leads to antigen-independent CAR-T cell activation, characterized by increased cell size and interferon (IFN)-γ secretion. This results in CAR-T cell exhaustion, activation-induced cell death and reduced responsiveness to target-antigen-expressing tumour cells. CDR mutagenesis confirms that the CAR-clustering is mediated by CDR-loops. In summary, antigen-independent tonic signalling can be induced by CDR-mediated CAR clustering, which could not be predicted from the scFv sequences, but could be tested for by evaluating the activity of unstimulated CAR-T cells.

Tailoring vascular phenotype through AAV therapy promotes anti-tumor immunity in glioma

Glioblastomas are aggressive brain tumors that are largely immunotherapy resistant. This is associated with immunosuppression and a dysfunctional tumor vasculature, which hinder T cell infiltration. LIGHT/TNFSF14 can induce high endothelial venules (HEVs) and tertiary lymphoid structures (TLS), suggesting that its therapeutic expression could promote T cell recruitment. Here, we use a brain endothelial cell-targeted adeno-associated viral (AAV) vector to express LIGHT in the glioma vasculature (AAV-LIGHT). We found that systemic AAV-LIGHT treatment induces tumor-associated HEVs and T cell-rich TLS, prolonging survival in αPD-1-resistant murine glioma. AAV-LIGHT treatment reduces T cell exhaustion and promotes TCF1⁺CD8⁺ stem-like T cells, which reside in TLS and intratumoral antigen-presenting niches. Tumor regression upon AAV-LIGHT therapy correlates with tumor-specific cytotoxic/memory T cell responses. Our work reveals that altering vascular phenotype through vessel-targeted expression of LIGHT promotes efficient anti-tumor T cell responses and prolongs survival in glioma. These findings have broader implications for treatment of other immunotherapy-resistant cancers.

The First Differentiated TB Care Model From India: Delays and Predictors of Losses in the Care Cascade

To reduce TB deaths in resource-limited settings, a differentiated care strategy can be used to triage patients with high risk of severe illness (i.e., those with very severe undernutrition, respiratory insufficiency, or inability to stand without support) at diagnosis and refer them for comprehensive assessment and inpatient care. Globally, there are few examples of implementing this type of strategy in routine program settings. Beginning in April 2022, the Indian state of Tamil Nadu implemented a differentiated care strategy called Tamil Nadu-Kasanoi Erappila Thittam (TN-KET) for all adults aged 15 years and older with drug-susceptible TB notified by public facilities. Before evaluating the impact on TB deaths, we sought to understand the retention and delays in the care cascade as well as predictors of losses. During April-June 2022, 14,961 TB patients were notified and 11,599 (78%) were triaged. Of those triaged, 1,509 (13%) were at high risk of severe illness; of these, 1,128 (75%) were comprehensively assessed at a nodal inpatient care facility. Of 993 confirmed as severely ill, 909 (92%) were admitted, with 8% unfavorable admission outcomes (4% deaths). Median admission duration was 4 days. From diagnosis, the median delay in triaging and admission of severely ill patients was 1 day each. Likelihood of triaging decreased for people with extrapulmonary TB, those diagnosed in high-notification districts or teaching hospitals, and those transferred out of district. Predictors of not being comprehensively assessed included: aged 25-34 years, able to stand without support, and diagnosis at a primary or secondary-level facility. Inability to stand without support was a predictor of unfavorable admission outcomes. To conclude, the first quarter of implementation suggests that TN-KET was feasible to implement but could be improved by addressing predictors of losses in the care cascade and increasing admission duration.

Abstract 1793: Single-cell RNA analysis reveal effector-like CD8+ CAR-T cell subpopulations associated with response in lymphoma patients

Although CD19-targeting CAR T cell therapy has shown remarkable success against B cell malignancies there is still room for improvement. To improve long-term responses amongst lymphoma patients, mechanisms underlying initial response and tumor relapses must be addressed. Recent studies have highlighted the importance of the quality of the starting cell material for CAR T cell production and the composition of the CAR T cell infusion product for clinical response. In our study, we have evaluated the clinical response to third generation anti-CD19 CAR T cell therapy in 23 patients with B cell lymphoma. Further, we evaluated the CAR T cell infusion products using targeted single-cell RNA sequencing and multi-color flow cytometry to find potential T cell subsets associating with clinical response. Patients were divided into responders (CR + PR) and non-responders (SD + PD) at the 1-month follow-up after treatment. The CAR T cell products of both responding and non-responding patients were dominated by CD8+ CAR T cells. When comparing cells from the two patient groups we found that the presence of effector-like CD8+ CAR T cells with a high cytotoxic and cytokine secretion and low dysfunction gene expression profile were associated with clinical response. Furthermore, CD8+ CAR T cells of responders displayed a higher polyfunctional gene expression profile, which has previously been shown to associate with clinical response. In contrast, CD8+ CAR T cells from the infusion products of non-responders displayed an elevated dysfunction gene expression profile. Our study reveals that single-cell RNA expression analysis of individual CAR T cell infusion product can identify subsets of effector cells correlating with clinical response. This can be used as a guidance in the CAR T cell production processes, to obtain CAR T cells with the desired characteristics.

Citation Format: Tina Sarén, Mohanraj Ramachandran, Gustav Gammelgård, Tanja Lövgren, Kristina Wikström, Jamileh Hashemi, Eva Freyhult, Claudio Mirabello, Åsa K Björklund, Håkan Ahlström, Rose-Marie Amini, Hans Hagberg, Angelica Loskog, Gunilla Enblad, Magnus Essand. Single-cell RNA analysis reveal effector-like CD8+ CAR-T cell subpopulations associated with response in lymphoma patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1793.

A Review on Various Biofuels and its Applications

Biofuels derived from biofuels, plant or algae or animal wastes. Unlike fossil fuels such as petroleum, coal and natural gas, refilled immediately. Biofuels are fuels made from recently harvested plants. They act like fossil fuels: they burn when ignited, releasing energy that can be converted into kinetic energy in a car, or heat a home. Biofuels can be obtained from a variety of crops and from a wide range of plant products from other industries. Not only is biodiesel stable, it is also a highly environmentally friendly, clean burning option that can be used without modification in diesel engines. In fact, biodiesel reduces greenhouse gas emissions by 56% to 86%, which means that the use of biodiesel has already reduced carbon emissions by 75.5 million metric tons. Many countries promote the use of biodiesel. In 2001, global biodiesel consumption was approximately 0.3 billion gallons. Based on the raw material, biofuels are divided into four groups: third, fourth (FGBs), first biodiesel, which is the only is a locally produced, clean-burning, renewable alternative to petroleum diesel. The use of biodiesel as a vehicle fuel enhances energy conservation, improves air quality and the environment, and provides safety benefits. Biofuels are transport fuels such as ethanol and biomass based diesel fuels. These fuels are usually blended with petroleum fuels (petrol and distillation / diesel fuel and heating oil), but can also be used on their own. Scientists have found that, in practice, biofuels produced from agricultural crops cause less pollution and greenhouse gas emissions than conventional fossil fuels, causing some environmental problems. Biofuels can also affect the poor. Various problems arise due to high prices for crops. It can go from improved water quality to creating new jobs in economically backward areas. Some applications of bioenergy require a feed based on residues from dedicated field production (such as energy crops) or agricultural production. However, many plant species grown for biofuels release higher levels of the ozone precursor isoprene than conventional crops and plants. Excess ozone poses a well-documented risk to human health, with 22,000 premature deaths each year linked to ground ozone exposure in Europe.

Upshot of Concentration of Zirconium (IV) Oxynitrate Hexa Hydrate on Preparation and Analyses of Zirconium Oxide (ZrO₂) Nanoparticles by Modified Co-Precipitation Method

In the present work, pure nanocrystalline monoclinic Zirconia (ZrO₂) has been successfully synthesized and optimized by the modified co-precipitation method. The concentration of raw material has been optimized with the fixed amount of precipitation agent (Potassium hydroxide KOH). The thermal history of the precursor has been examined through TG/DTA analysis. All the samples are subjected to study the structure, fingerprints of the molecular vibrations, and morphology analyses. The representative sample has been analyzed through Transmission Electron Microscope (TEM) and X-ray Photo Electron Spectroscopy (XPS) analyses. The as-prepared sample exhibits the better crystallinity and surface morphology with lesser particle size (190 nm) when the raw material concentration is 0.2 M. The as-prepared ZrO₂ filler (0, 3, 6, 9, and 12 wt.%) is spread through the enhanced polymer electrolyte P(S-MMA) (27 Wt.%)-LiClO₄ (8 wt.%)-EC + PC (1;1 of 65 wt.%) complex system via solution casting method. The as-synthesized electrolyte films are examined via complex impedance analysis. P(S-MMA) (27 wt.%)-LiCIO₄ (8 wt.%)-EC + PC (1 ;1 of 65 wt.%)-6 wt.% of ZrO₂ shows the high ionic conductivity 2.35 × 10^-3 Scm^-1. Temperature-dependent ionic conductivity studies obey the non-linear behavior. The enhanced ZrO₂ has been expected to enhance the other electrochemical properties of the lithium secondary battery.

Tertiary Lymphoid Structures in the Central Nervous System: Implications for Glioblastoma

Glioblastoma is the most common and aggressive brain tumor, which is uniformly lethal due to its extreme invasiveness and the absence of curative therapies. Immune checkpoint inhibitors have not yet proven efficacious for glioblastoma patients, due in part to the low prevalence of tumor-reactive T cells within the tumor microenvironment. The priming of tumor antigen-directed T cells in the cervical lymph nodes is complicated by the shortage of dendritic cells and lack of appropriate lymphatic vessels within the brain parenchyma. However, recent data suggest that naive T cells may also be primed within brain tumor-associated tertiary lymphoid structures. Here, we review the current understanding of the formation of these structures within the central nervous system, and hypothesize that promotion of tertiary lymphoid structures could enhance priming of tumor antigen-targeted T cells and sensitize glioblastomas to cancer immunotherapy.

ELTD1-deletion reduces vascular abnormality and improves T-cell recruitment after PD-1 blockade in glioma

Background

Tumor vessels in glioma are molecularly and functionally abnormal, contributing to treatment resistance. Proteins differentially expressed in glioma vessels can change vessel phenotype and be targeted for therapy. ELTD1 (Adgrl4) is an orphan member of the adhesion G-protein-coupled receptor family upregulated in glioma vessels and has been suggested as a potential therapeutic target. However, the role of ELTD1 in regulating vessel function in glioblastoma is poorly understood.

Methods

ELTD1 expression in human gliomas and its association with patient survival was determined using tissue microarrays and public databases. The role of ELTD1 in regulating tumor vessel phenotype was analyzed using orthotopic glioma models and ELTD1^−/− mice. Endothelial cells isolated from murine gliomas were transcriptionally profiled to determine differentially expressed genes and pathways. The consequence of ELTD1 deletion on glioma immunity was determined by treating tumor-bearing mice with PD-1-blocking antibodies.

Results

ELTD1 levels were upregulated in human glioma vessels, increased with tumor malignancy, and were associated with poor patient survival. Progression of orthotopic gliomas was not affected by ELTD1 deletion, however, tumor vascular function was improved in ELTD1^−/− mice. Bioinformatic analysis of differentially expressed genes indicated increased inflammatory response and decreased proliferation in tumor endothelium in ELTD1^−/− mice. Consistent with an enhanced inflammatory response, ELTD1 deletion improved T-cell infiltration in GL261-bearing mice after PD-1 checkpoint blockade.

Conclusion

Our data demonstrate that ELTD1 participates in inducing vascular dysfunction in glioma, and suggest that targeting of ELTD1 may normalize the vessels and improve the response to immunotherapy.

Agonistic CD40 therapy induces tertiary lymphoid structures but impairs responses to checkpoint blockade in glioma

Gliomas are brain tumors characterized by an immunosuppressive microenvironment. Immunostimulatory agonistic CD40 antibodies (αCD40) are in clinical development for solid tumors, but are yet to be evaluated for glioma. Here, we demonstrate that systemic delivery of αCD40 in preclinical glioma models induces the formation of tertiary lymphoid structures (TLS) in proximity of meningeal tissue. In treatment-naïve glioma patients, the presence of TLS correlates with increased T cell infiltration. However, systemic delivery of αCD40 induces hypofunctional T cells and impairs the response to immune checkpoint inhibitors in pre-clinical glioma models. This is associated with a systemic induction of suppressive CD11b⁺ B cells post-αCD40 treatment, which accumulate in the tumor microenvironment. Our work unveils the pleiotropic effects of αCD40 therapy in glioma and reveals that immunotherapies can modulate TLS formation in the brain, opening up for future opportunities to regulate the immune response.

Agonistic CD40 antibodies (αCD40) have broad immunostimulatory properties, however their efficacy in glioma remains unclear. Here the authors show that αCD40 promotes the formation of tertiary lymphoid structures but does not improve survival and impairs the response to immune checkpoint blockade in murine glioma models.

Concurrent expression of HP-NAP enhances antitumor efficacy of oncolytic vaccinia virus but not for Semliki Forest virus

Oncolytic viruses (OVs) represent promising therapeutic agents for cancer therapy by selective oncolysis and induction of anti-tumor immunity. OVs can be engineered to express tumor-associated antigens and immune-modulating agents to provoke stronger antitumor immunity. Here, we engineered vaccinia virus (VV) and Semliki Forest virus (SFV) to express neuroblastoma-associated antigen disialoganglioside (GD2) and the immune modulator Helicobacter pylori neutrophil-activating protein (NAP) and compared their therapeutic potency. Oncolytic VV did not exhibit any antitumor benefits, whereas SFV was able to delay subcutaneous neuroblastoma (NXS2) tumor growth. Additional expression of the GD2 mimotope (GD2m) by VV-GD2m or SFV-GD2m did not improve their anti-tumor capacity compared to the parent viruses. Further arming these OVs with NAP resulted in contrasting anti-tumor efficacy. VV (VV-GD2m-NAP) significantly improved therapeutic efficacy compared to VV-GD2m, which was also associated with a significantly elevated anti-GD2 antibody, whereas there was no additive antitumor efficacy for SFV-GD2m-NAP compared to SFV-GD2m, nor was the anti-GD2 antibody response improved. Instead, NAP induced higher neutralizing antibodies against SFV. These observations suggest that distinct immune stimulation profiles are elicited when the same immunostimulatory factor is expressed by different OVs. Therefore, careful consideration and detailed characterization are needed when engineering OVs with immune-modulators.

IFN-I-tolerant oncolytic Semliki Forest virus in combination with anti-PD1 enhances T cell response against mouse glioma

Oncolytic virotherapy holds promise of effective immunotherapy against otherwise nonresponsive cancers such as glioblastoma. Our previous findings have shown that although oncolytic Semliki Forest virus (SFV) is effective against various mouse glioblastoma models, its therapeutic potency is hampered by type I interferon (IFN-I)-mediated antiviral signaling. In this study, we constructed a novel IFN-I-resistant SFV construct, SFV-AM6, and evaluated its therapeutic potency in vitro, ex vivo, and in vivo in the IFN-I competent mouse GL261 glioma model. In vitro analysis shows that SFV-AM6 causes immunogenic apoptosis in GL261 cells despite high IFN-I signaling. MicroRNA-124 de-targeted SFV-AM6-124T selectively replicates in glioma cells, and it can infect orthotopic GL261 gliomas when administered intraperitoneally. The combination of SFV-AM6-124T and anti-programmed death 1 (PD1) immunotherapy resulted in increased immune cell infiltration in GL261 gliomas, including an increased tumor-reactive CD8⁺ fraction. Our results show that SFV-AM6-124T can overcome hurdles of innate anti-viral signaling. Combination therapy with SFV-AM6-124T and anti-PD1 promotes the inflammatory response and improves the immune microenvironment in the GL261 glioma model.

The aqueous dependent sensing of hydrazine and phosphate anions using a bis-heteroleptic Ru(II) complex with a phthalimide-anchored pyridine-triazole ligand

Selective turn-on luminescence properties are shown by a non-luminescent metalloreceptor upon the addition of phosphate anions in CH3CN and hydrazine in CH3CN/H2O (6/4, v/v). The non-luminescent metalloreceptors [RuII(phen)2(TpH)]2PF6- (RtpH) and [RuII(Phen)2(TpI)]2PF6- (RtpI) {phen = 1,10-phenanthroline; TpH = 2-(2-(4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl)ethyl)isoindoline-1,3-dione; and TpI = 2-(2-(5-iodo-4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl)ethyl)isoindoline-1,3-dione} were synthesized and characterized. Both metalloreceptors have excellent sensing properties for phosphate anions (H2PO4- and H2P2O72-) over other anions in CH3CN. The limit of detection (LOD) values were calculated to be 79 nM and 48 nM for H2PO4- upon addition to RtpH and RtpI, respectively. Noncovalent interactions play a key role in the sensing of phosphate anions, among which the halogen-anion interaction showed superior recognition properties over the hydrogen-anion interaction. Comparative electrochemical experiments, 1H NMR titration, 31P NMR titration, and lifetime studies also show that RtpI has better sensing properties, as evidenced by its more drastic emission response to H2PO4- anions compared with RtpH. Moreover, the metalloreceptors showed a remarkable fluorescence increase (at ∼584 nm) upon the addition of hydrazine, without the interference of other amines in CH3CN/H2O (6/4, v/v). Interestingly, fluorescence enhancement was observed within live HeLa cells upon hydrazine addition, which is caused by the efficient photoinduced electron transfer process.

Two-year clinical results of a novel load redistribution device for the treatment of medial knee OA

PURPOSE

A potential method to relieve the pain from medial osteoarthritis of the knee is to offload the medial compartment. The Latella^™ Knee Implant is a novel device designed to offload the medial compartment. The objective of the Cotera-1 study was to evaluate the preliminary safety and feasibility of the Latella implant to treat patients with medial OA of the knee, by a 2-year follow-up of a prospective multicenter feasibility study (Cotera-1) performed in the Netherlands and UK METHODS: In this first-in-man study, 11 participants received the Latella implant and were followed for 2 years, documenting physician assessment, Patient-Reported Outcome (PRO) scoring (KOOS, IKDC, Kujala, SF-36); Patient Global Assessment (PGA), radiographic analysis and MRI analysis, complications, reoperation rate and hip-knee-ankle axis.

RESULTS

The Latella Knee Implant system proved to be well tolerated and demonstrated a low-risk safety profile up to 24 months post-treatment. A responder analysis was performed of the subjects who still had the Latella implanted at 24-month time point (n = 9). Based on a MCID of eight for KOOS pain sub-scale, 78% of the subjects at the 24 month time point would be considered as responders. Similarly, based on improvement in the medial knee pain compared to baseline using the NRS scale of 1-10, 89% of the subjects at the 24-month time point would be considered as responders. Two patients were revised during follow-up: one for arthrofibrosis and one converted to TKA for progression of OA.

CONCLUSIONS

The early clinical experience with the Latella Knee Implant in this pilot feasibility study has been encouraging. It appears to be a safe implant with possible effect on medial OA. Additional studies need to be performed to assess the safety and efficacy of the procedure in a larger patient population.

LEVEL OF EVIDENCE

II.

Appropriateness of metformin prescription for type 2 diabetes mellitus patients with chronic kidney disease (Stages 3-5)

INTRODUCTION

Metformin is the first-line pharmacological therapy for type 2 diabetes mellitus (T2DM). Guidelines recommend metformin to be given at reduced dosages for those with an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73m² and omitted in those with eGFR<30 mL/min/1.73m². Lactic acidosis is a known complication of those on metformin. This study aimed to determine the appropriateness of metformin prescription in T2DM patients with chronic kidney disease (CKD) stages 3-5 in a tertiary centre in Malaysia.

MATERIALS AND METHODS

A cross-sectional design using retrospective secondary data of T2DM patients on metformin attending nephrology and diabetic clinics in the year 2017. eGFR calculated using the CKD-EPI formula identified those in CKD stage 3-5 defined using the National Kidney Foundation-Kidney Disease Outcomes Quality Initiative criteria. Metformin prescription was considered appropriate when the metformin maximum daily dosage does not exceed 1500 mg in CKD stage 3a and 1000 mg in CKD stage 3b and metformin stopped in CKD stages 4 and 5.

RESULTS

A total of 143 patients were included. Majority were in the elderly age group (62.9%), male (60.8%) and had concurrent hypertension (85.3%). Median HbA1c was 8.3% (67 mmol/mol) with most patients (88.8%) having HbA1c above 6.5% (48 mmol/ mol). Majority (92.3%) were categorised as stage 3 CKD. Eleven (7.7%) subjects had inappropriate metformin prescription. Seven of nine (78%) subjects in CKD stage 4 were on metformin with a maximum daily dose of 500 mg to1000 mg. Three patients had serum lactate measured.

CONCLUSION

The majority of CKD patients had appropriate metformin prescription. However, a considerable number of CKD stage 4 patients continued to be on metformin. The many benefits of metformin may be a reason why it is still continued against recommendations. Only three patients had lactate measured which, although may suggest that lactic acidosis is not a common occurrence, the potential for metformin-associated lactic acidosis especially in those at risk should be considered.

Tumor endothelial cell up-regulation of IDO1 is an immunosuppressive feed-back mechanism that reduces the response to CD40-stimulating immunotherapy

CD40-stimulating immunotherapy can elicit potent anti-tumor responses by activating dendritic cells and enhancing T-cell priming. Tumor vessels orchestrate T-cell recruitment during immune response, but the effect of CD40-stimulating immunotherapy on tumor endothelial cells has not been evaluated. Here, we have investigated how tumor endothelial cells transcriptionally respond to CD40-stimulating immunotherapy by isolating tumor endothelial cells from agonistic CD40 mAb- or isotype-treated mice bearing B16-F10 melanoma, and performing RNA-sequencing. Gene set enrichment analysis revealed that agonistic CD40 mAb therapy increased interferon (IFN)-related responses in tumor endothelial cells, including up-regulation of the immunosuppressive enzyme Indoleamine 2, 3-Dioxygenase 1 (IDO1). IDO1 was predominantly expressed in endothelial cells within the tumor microenvironment, and its expression in tumor endothelium was positively correlated to T-cell infiltration and to increased intratumoral expression of IFNγ. In vitro, endothelial cells up-regulated IDO1 in response to T-cell-derived IFNγ, but not in response to CD40-stimulation. Combining agonistic CD40 mAb therapy with the IDO1 inhibitor epacadostat delayed tumor growth in B16-F10 melanoma, associated with increased activation of tumor-infiltrating T-cells. Hereby, we show that the tumor endothelial cells up-regulate IDO1 upon CD40-stimulating immunotherapy in response to increased IFNγ-secretion by T-cells, revealing a novel immunosuppressive feedback mechanism whereby tumor vessels limit T-cell activation.

Characterization of virus-mediated immunogenic cancer cell death and the consequences for oncolytic virus-based immunotherapy of cancer

Oncolytic viruses have the potential to induce immunogenic cell death (ICD) that may provoke potent and long-lasting anti-cancer immunity. Here we aimed to characterize the ICD-inducing ability of wild-type Adenovirus (Ad), Semliki Forest virus (SFV) and Vaccinia virus (VV). We did so by investigating the cell death and immune-activating properties of virus-killed tumor cells. Ad-infection of tumor cells primarily activates autophagy, but also activate events of necroptotic and pyroptotic cell death. SFV infection on the other hand primarily activates immunogenic apoptosis while VV activates necroptosis. All viruses mediated lysis of tumor cells leading to the release of danger-associated molecular patterns, triggering of phagocytosis and maturation of dendritic cells (DCs). However, only SFV-infected tumor cells triggered significant T helper type 1 (Th1)-cytokine release by DCs and induced antigen-specific T-cell activation. Our results elucidate cell death processes activated upon Ad, SFV, and VV infection and their potential to induce T cell-mediated anti-tumor immune responses. This knowledge provides important insight for the choice and design of therapeutically successful virus-based immunotherapies.

Triazole appending ruthenium(ii) polypyridine complex for selective sensing of phosphate anions through C–H–anion interaction and copper(ii) ions via cancer cells

Selective fluorescence enhancement by H₂PO₄⁻/H₂P₂O₇²⁻ anions and maximum fluorescence quenching by Cu²⁺ ions were attained upon treatment with different types of anions and cations, respectively.

Tumor angiogenesis: causes, consequences, challenges and opportunities

Tumor vascularization occurs through several distinct biological processes, which not only vary between tumor type and anatomic location, but also occur simultaneously within the same cancer tissue. These processes are orchestrated by a range of secreted factors and signaling pathways and can involve participation of non-endothelial cells, such as progenitors or cancer stem cells. Anti-angiogenic therapies using either antibodies or tyrosine kinase inhibitors have been approved to treat several types of cancer. However, the benefit of treatment has so far been modest, some patients not responding at all and others acquiring resistance. It is becoming increasingly clear that blocking tumors from accessing the circulation is not an easy task to accomplish. Tumor vessel functionality and gene expression often differ vastly when comparing different cancer subtypes, and vessel phenotype can be markedly heterogeneous within a single tumor. Here, we summarize the current understanding of cellular and molecular mechanisms involved in tumor angiogenesis and discuss challenges and opportunities associated with vascular targeting.

Abstract A159: Agonistic CD40 antibody therapy induces formation of tertiary lymphoid structures in glioma and inhibits the response to immune-checkpoint blockade

Cancer immunotherapy of glioma, the most common primary brain tumor in adults, is constrained by an immunosuppressive microenvironment. Tertiary lymphoid structures (TLSs) are ectopic lymphoid structures that mediate immune responses and provide a local site for tumor antigen presentation. Here, we show for the first time that TLSs are present in human low-grade glioma and that they can be induced in murine glioma models. Agonistic CD40 antibodies induced lymphotoxin α expression in B cells and enhanced the formation of TLSs in mice bearing orthotopic GL261 or CT-2A gliomas. TLSs consisting of B cells, T-cells and antigen presenting cells formed around CD31+ vessels proximal to the tumor tissue and adjacent to the meninges. Agonistic CD40 antibody treatment improved the CD8+ T-cell / Treg ratio in tumor-bearing mice, but there was no survival benefit. A decreased CD69 activation status on CD8+ T-cells, an increase of B cells with a CD1d+CD5+ regulatory phenotype and a high infiltration of Tregs in TLSs indicate that agonistic CD40 antibodies induce an immunosuppressive microenvironment in glioma. Consistent with this, the efficacy of both PD-1 and CTLA-4 checkpoint blockade was significantly decreased by co-administration of agonistic CD40 antibodies. These results demonstrate that TLSs are present and can be induced in glioma, but that they at least under certain conditions are associated with immunosuppression, shedding light on new mechanisms of immune regulation in the brain microenvironment.

Citation Format: Luuk van Hooren, Alessandra Vaccaro, Maria Georganaki, Mohanraj Ramachandran, Hua Huang, Joey Lau, Anja Smits, Magnus Essand, Anna Dimberg. Agonistic CD40 antibody therapy induces formation of tertiary lymphoid structures in glioma and inhibits the response to immune-checkpoint blockade [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A159.

Abstract B181: Adenovirus, Semliki Forest virus and vaccinia virus-induced immunogenic cell death augments oncolytic virus immunotherapy

Oncolytic viruses represent new immunotherapy agents with therapeutic effects consisting of direct oncolysis of cancer cells and anticancer immune responses induced upon oncolysis. However, the exact pathways of cell death and the subsequent immune response initiations after oncolysis are not fully elucidated. We have examined the cell death pathways and immune-stimulatory pathways involved in adenovirus (Ad), Semliki Forest virus (SFV) and vaccinia virus (VV) infection. The three viruses activate distinct but different pathways but all of them induced immunogenic cell death (ICD), which is depicted by elevated cell surface exposure of calreticulin (CRT) and extracellular secretion of ATP. Oncolysis-mediated ICD grants dying cells to be phagocytosed and it promotes DC maturation and activation with a Th1-polarized cytokine secretion profile. As a proof of concept, we validated that when DCs are incubated with Ad- or SFV-, but not VV-infected tumor cells expressing a surrogate antigen (CMVpp65), they can efficiently process and cross-present peptides of this antigen to CD8+ T-cells, as shown by specific IFN-γ production. Mice immunized with SFV- or VV-infected murine glioblastoma cells (GL261) elicit a strong and specific T-cell response against GL261. This adaptive immune response can control tumor growth and prolong mice survival after GL261 rechallenge.

Citation Format: Mohanraj Ramachandran, Magnus Essand. Adenovirus, Semliki Forest virus and vaccinia virus-induced immunogenic cell death augments oncolytic virus immunotherapy [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr B181.

Abstract B175: Semliki Forest virus-mediated oncolytic immunotherapy in mouse GL261 glioblastoma model

Glioblastoma (GBM) is a devastating cancer of the central nervous system with no cure currently available. Oncolytic virotherapy with viruses that infect and destroy cancer cells provides a novel promising candidate therapy. We have previously shown that Semliki Forest virus (SFV) has therapeutic potency against orthotopic xenograft and syngeneic glioma models in mice. Here we show that SFV-infected cancer cells undergo immunogenic apoptosis, which triggers phagocytosis and maturation in co-cultured dendritic cells. SFV-killed GL261 mouse GBM cell lysate was also able to induce protective antitumor immune response in syngeneic mouse model, indicating that SFV oncolysis is immunogenic in vivo. By introducing mutations into the viral genome we have been able to produce a novel SFV clone which shows notably enhanced oncolytic potency in GL261 cells. As compared to the wild-type virus, the mutated SFV replicates faster and induces significantly stronger cytopathic effect. Robust viral replication and cytopathic effect were detected despite of activated type-I interferon signaling in the infected cells. This suggests that the enhanced SFV has increased resistance to antiviral response in mouse GBM cells. Viral proteins were detected by immunohistochemistry in orthotopic GL261 tumors after intratumoral injection of the mutated SFV virus. This provides evidence that the enhanced SFV is able to replicate in GL261 tumors in the face of antiviral in vivo microenvironment. Unwanted SFV replication in healthy brain cells can be inhibited by microRNA-mediated de-targeting. Taken together, the results indicate that oncolytic virotherapy with SFV can trigger antitumor immune responses, and support that SFV is a potent new candidate for oncolytic immunotherapy of GBM. These findings pave way for future clinical trials with oncolytic SFV.

Citation Format: Miika Martikainen, Di Yu, Mohanraj Ramachandran, Grammatiki Fotaki, Minttu-Maria Martikainen, Andres Merits, Magnus Essand. Semliki Forest virus-mediated oncolytic immunotherapy in mouse GL261 glioblastoma model [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr B175.

Abstract B110: Proinflammatory allogeneic dendritic cells promote activation of bystander immune cells and indirectly license antigen-specific T-cells

Autologous patient-derived dendritic cells (DCs) modified ex vivo to present tumor-associated antigens have frequently been utilized as cancer vaccines. However, apart from the stringent logistics in producing DCs on a patient basis, accumulating evidences indicate that such DCs are poor in migration and in fact do not directly interact with naïve T-cells in vivo. Instead, it is the bystander host-DCs taking up material from apoptotic vaccine DCs and subsequently initiate antitumor T-cell responses. We examine the possibility of harnessing allogeneic pro-inflammatory DCs (alloDCs) as immune enhancers which may affect the activation of bystander immune cells and promote antigen-specific T-cell responses. We have verified the inflammatory state of DCs matured with a maturation cocktail in combination with an infection-enhanced adenovirus. Such proinflammatory alloDCs expressed co-stimulatory and activation molecules and secreted Th-1 type cytokines in vitro. T and NK cells up-regulated activation markers after co-culture with such alloDCs and created an immunostimulatory environment which was found to promote maturation of antigen-loaded DCs and the subsequent activation of antigen-specific T-cells by cross-presentation. Our findings were evaluated as a therapeutic strategy in murine models with success. We are proposing that vaccination with proinflammatory alloDCs in combination with the use of Ad5M as possible antigen delivery vehicle can be a cost-effective strategy to induce antitumor immune responses.

Citation Format: Grammatiki Fotaki, Chuan Jin, Iliana Kyriaki Kerzeli, Mohanraj Ramachandran, Alex Karlsson-Parra, Di Yu, Magnus Essand. Proinflammatory allogeneic dendritic cells promote activation of bystander immune cells and indirectly license antigen-specific T-cells [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr B110.

Abstract A041: Hypoxia-responsive CAR T-cells

In recent years, CD19 CAR T-cell therapy has been successfully implemented against therapy-resistant B-cell malignancies. The results are especially striking for acute lymphoblastic leukemia (ALL), while results are somewhat less stunning when it comes to lymphoma. This is in part due to the semi-solid structure of lymphoma with an immune suppressive tumor microenvironment and less oxygenated areas within the tumors. These obstacles become even more pronounced in solid tumors. Furthermore, in the case of solid tumors the lack of tumor-specific antigens represents a major challenge. Instead, overexpressed tumor-associated antigens (TAAs) are often used as targets in CAR T-cell therapy of solid tumors. However, as TAAs are also expressed to some extent in normal tissue, targeting these antigens may result in severe OFF-tumor ON-target toxicity. In the case of CD19 CAR T-cell therapy of B-cell malignancies, OFF-tumor ON-target toxicity causes B-cell aplasia.The aim of this study was to reduce OFF-tumor ON-target toxicity by engineering CAR T-cells that mainly express the CAR molecule in the hypoxic tumor microenvironment. Hypoxia-inducible factor 1 (HIF1) is a transcription factor that is a major mediator of hypoxia-induced gene expression as it binds to hypoxia response elements (HREs) in promoter regions of hypoxia-responsive genes and initiates their expression. In this study, a cassette of HREs was inserted together with a minimal CMV (mCMV) promoter in front of the CD19 CAR cassette to promote expression during hypoxic conditions. Chemically induced hypoxia augmented CD19 CAR expression over time in hypoxia-responsive CD19 CAR T-cells (HRE-mCMV-CD19CAR-GFP), whereas CAR expression was unaffected in CD19 CAR T-cells with constitutively expressed CAR (EF1α-CD19CAR-GFP). Furthermore, hypoxia-responsive CAR T-cells had an increased activation status and killing capacity upon antigen encounter in hypoxic compared to normoxic conditions. This design could be evaluated in the clinic to reduce B-cell aplasia in CD19 CAR T-cell therapy of lymphomas and especially to reduce OFF-target toxicities from CAR T-cells targeting TAAs in solid tumors.

Citation Format: Tina Anna Sarén, Anne Marie Senz, Mohanraj Ramachandran, Di Yu, Magnus Essand. Hypoxia-responsive CAR T-cells [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A041.

A luminescent on–off probe based calix[4]arene linked through triazole with ruthenium(ii) polypyridine complexes to sense copper(ii) and sulfide ions

The supramolecular sensor Ru2L was designed by joining a bis-ruthenium(ii) polypyridyl complex with a p-tert-butyl calix[4]arene platform through a 1,2,3-triazole linker and used for sensing of copper(ii) and sulfide ions by fluorescence.

Facile Synthesis and Characterization of ZrO₂ Nanoparticles via Modified Co-Precipitation Method

The crystalline Zirconium oxide (ZrO2) nano particles were synthesized using optimized content of Zirconium nitrate (Zr(NO3)2·3H2O) with varying KOH concentration (0.5, 1 and 1.5 M) by co-precipitation method. The thermal history of the precursor was carefully analyzed through Thermogravimetric (TG/DTA) measurement. The as prepared samples were characterized to ensure structural, functional, morphological, compositional, chemical composition and band gap by X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), Laser Raman, scanning electron microscopy (SEM), High resolution Transverse Electron Microscopy (HR-TEM), X-ray photo electron spectroscopy (XPS), EDX, Photo luminescence spectroscopy (PL). The monoclinic structure with space group P21/c has been confirmed from XRD (JCPDS 89-9066). The Zr-O stretching vibration and Zr-O2-Zr bending vibrations were confirmed through FTIR analysis. The well dispersed particles with spherical morphology were confirmed through SEM and TEM analysis. The oxidation states of Zr, O and C were confirmed through XPS analysis. The oxygen vacancies and band gap of the particles were investigated through PL analysis.

Cancer vaccine based on a combination of an infection-enhanced adenoviral vector and pro-inflammatory allogeneic DCs leads to sustained antigen-specific immune responses in three melanoma models

Autologous patient-derived dendritic cells (DCs) modified ex vivo to present tumor-associated antigens (TAAs) are frequently used as cancer vaccines. However, apart from the stringent logistics in producing DCs on a patient basis, accumulating evidence indicate that ex vivo engineered DCs are poor in migration and in fact do not directly present TAA epitopes to naïve T cells in vivo. Instead, it is proposed that bystander host DCs take up material from vaccine-DCs, migrate and subsequently initiate antitumor T-cell responses. We used mouse models to examine the possibility of using pro-inflammatory allogeneic DCs (alloDCs) to activate host DCs and enable them to promote antigen-specific T-cell immunity. We found that alloDCs were able to initiate host DC activation and migration to draining lymph node leading to T-cell activation. The pro-inflammatory milieu created by alloDCs also led to recruitment of NK cells and neutrophils at the site of injection. Vaccination with alloDCs combined with Ad5M(gp100), an infection-enhanced adenovirus encoding the human melanoma-associated antigen gp100 resulted in generation of CD8⁺ T cells with a T-cell receptor (TCR) specific for the gp100_25-33 epitope (gp100-TCR⁺). Ad5M(gp100)-alloDC vaccination in combination with transfer of gp100-specific pmel-1 T cells resulted in prolonged survival of B16-F10 melanoma-bearing mice and altered the composition of the tumor microenvironment (TME). We hereby propose that alloDCs together with TAA- or neoepitope-encoding Ad5M can become an “off-the-shelf” cancer vaccine, which can reverse the TME-induced immunosuppression and induce host cellular anti-tumor immune responses in patients without the need of a time-consuming preparation step of autologous DCs.

Pro-inflammatory allogeneic DCs promote activation of bystander immune cells and thereby license antigen-specific T-cell responses

Accumulating evidence support an important role for endogenous bystander dendritic cells (DCs) in the efficiency of autologous patient-derived DC-vaccines, as bystander DCs take up material from vaccine-DCs, migrate to draining lymph node and initiate antitumor T-cell responses. We examined the possibility of using allogeneic DCs as vaccine-DCs to activate bystander immune cells and promote antigen-specific T-cell responses. We demonstrate that human DCs matured with polyI:C, R848 and IFN-γ (denoted COMBIG) in combination with an infection-enhanced adenovirus vector (denoted Ad5M) exhibit a pro-inflammatory state. COMBIG/Ad5M-matured allogeneic DCs (alloDCs) efficiently activated T-cells and NK-cells in allogeneic co-culture experiments. The secretion of immunostimulatory factors during the co-culture promoted the maturation of bystander-DCs, which efficiently cross-presented a model-antigen to activate antigen-specific CD8+ T-cells in vitro. We propose that alloDCs, in combination with Ad5M as loading vehicle, may be a cost-effective and logistically simplified DC vaccination strategy to induce anti-tumor immune responses in cancer patients.

Safe and Effective Treatment of Experimental Neuroblastoma and Glioblastoma Using Systemically Delivered Triple MicroRNA-Detargeted Oncolytic Semliki Forest Virus

Background: Glioblastoma multiforme and high-risk neuroblastoma are cancers with poor outcome. Immunotherapy in the form of neurotropic oncolytic viruses is a promising therapeutic approach for these malignancies. Here we evaluate the oncolytic capacity of the neurovirulent and partly IFNβ-resistant Semliki Forest virus (SFV)-4 in glioblastoma multiformes and neuroblastomas. To reduce neurovirulence we constructed SFV4miRT, which is attenuated in normal central nervous system (CNS) cells through insertion of microRNA target sequences for miR124, miR125, miR134.Methods: Oncolytic activity of SFV4miRT was examined in mouse neuroblastoma and glioblastoma multiforme cell lines and in patient-derived human glioblastoma cell cultures (HGCC). In vivo neurovirulence and therapeutic efficacy was evaluated in two syngeneic orthotopic glioma models (CT-2A, GL261) and a syngeneic subcutaneous neuroblastoma model (NXS2). The role of IFNβ in inhibiting therapeutic efficacy was investigated.Results: The introduction of miRNA target sequences reduced neurovirulence of SFV4 in terms of attenuated replication in mouse CNS cells and ability to cause encephalitis when administered intravenously. A single intravenous injection of SFV4miRT prolonged survival and cured four of eight mice (50%) with NXS2 and three of 11 mice (27%) with CT-2A, but not for GL261 tumor-bearing mice. In vivo therapeutic efficacy in different tumor models inversely correlated to secretion of IFNβ by respective cells upon SFV4 infection in vitro Similarly, killing efficacy of HGCC lines inversely correlated to IFNβ response and interferon-α/β receptor-1 expression.Conclusions: SFV4miRT has reduced neurovirulence, while retaining its oncolytic capacity. SFV4miRT is an excellent candidate for treatment of glioblastoma multiforme and neuroblastoma with low IFN-β secretion. Clin Cancer Res; 23(6); 1519-30. ©2016 AACR.

Abstract 2311: Adenovirus-transduced allogeneic dendritic cells for cancer immunotherapy

Immunotherapy is currently being established as standard treatment for cancer. Immune checkpoint blockade antibodies can cure a large proportion of patients with refractory melanoma and lung cancer, and adoptive transfer of patient-derived CD19 chimeric antigen receptor (CAR) T cells results in complete remission in a majority of patient with refractory leukemia. Cancer vaccines based on patient-derived dendritic cells (DC) modified ex vivo to present tumor antigens are promising for cancer treatment especially when combined with immune checkpoint blockade antibodies. Ex vivo-modified DCs are however poor in migrating to secondary lymphoid organs after re-administration. In reality, it is more likely endogenous DC that endocytos the injected DC, mature and then migrate to lymph nodes where they present peptide fragments of tumor antigen to T cells together with required co-stimulation.

Herein, we present a new strategy utilizing adenovirus (Ad)-transduced allogeneic DCs (alloDCs) as immunostimulatory adjuvant to induce both innate and adaptive immune response. Ad/alloDC can be prepared, tested and made ready for release in advance and quickly be prepared for injection in cancer patients upon request, thereby minimizing GMP-processing and handling of cells. Besides encoding tumor antigens, adenovirus also provides stimulatory danger signals for DC activation. We show that Ad/alloDCs secret a panel of proinflammatory cytokines and chemokines including IL-12 and CXCL10 at high levels in a sustainable fashion. We also show that Ad/alloDC recruit and activate neutrophils and NKs to the site of injection. Ad/alloDC can also recruit and interact with allo-reactive T cells to create a proinflammatory milieu, which further recruit and activate endogenous DCs. We verified that endogenous DCs activated in situ by an Ad/alloDC injection migrate to draining lymph node, where they present the engulfed tumor antigen to T cells. We show that these migratory endogenous DCs facilitate T cell activation and proliferation. Moreover, when injected intratumorally, Ad/alloDCs modulate the immunosuppressive environment by reducing the ratio of monocytic to granulocytic myeloid-derived suppressor cells (MDSC). To evaluate the therapeutic efficacy, we use B16 melanoma tumor-bearing C57Bl/6 mice injected with adenovirus-transduced DCs from Balb/c origin to obtain an allogeneic reaction. We show that Ad/alloDC treatment could significantly delay tumor growth and prolong survival of tumor-bearing mice.

Citation Format: Magnus Essand, Grammatiki Fotaki, Chuan Jin, Mohanraj Ramachandran, Jing Ma, Alex Karlsson-Parra, Di Yu. Adenovirus-transduced allogeneic dendritic cells for cancer immunotherapy. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2311.

Safe engineering of CAR T cells for adoptive cell therapy of cancer using long-term episomal gene transfer

Chimeric antigen receptor (CAR) T‐cell therapy is a new successful treatment for refractory B‐cell leukemia. Successful therapeutic outcome depends on long‐term expression of CAR transgene in T cells, which is achieved by delivering transgene using integrating gamma retrovirus (RV) or lentivirus (LV). However, uncontrolled RV/LV integration in host cell genomes has the potential risk of causing insertional mutagenesis. Herein, we describe a novel episomal long‐term cell engineering method using non‐integrating lentiviral (NILV) vector containing a scaffold/matrix attachment region (S/MAR) element, for either expression of transgenes or silencing of target genes. The insertional events of this vector into the genome of host cells are below detection level. CD19 CAR T cells engineered with a NILV‐S/MAR vector have similar levels of CAR expression as T cells engineered with an integrating LV vector, even after numerous rounds of cell division. NILV‐S/MAR‐engineered CD19 CAR T cells exhibited similar cytotoxic capacity upon CD19⁺ target cell recognition as LV‐engineered T cells and are as effective in controlling tumor growth in vivo. We propose that NILV‐S/MAR vectors are superior to current options as they enable long‐term transgene expression without the risk of insertional mutagenesis and genotoxicity.

Abstract A171: Long-term episomal gene transfer for safe engineering of T cells for adoptive cell therapy of cancer

Success in T-cell therapy of cancer is currently relying on long-term gene expression owing to retrovirus/lentivirus (RV/LV) integration. However, uncontrolled RV/LV integration in host cell genomes has the potential risk of causing insertional mutagenesis. Herein, we describe a novel episomal and long-term cell engineering method using non-integrating lentiviral (NILV) vector containing a scaffold matrix attachment region (S/MAR) element for either over-expression or down-regulation of genes. T-cells engineered with a NILV-S/MAR(CD19CAR) vector have similar levels of CAR expression as T-cells engineered with an integrating LV vector, even after numerous rounds of cell division. NILV-S/MAR-engineered CD19CAR-T-cells exhibited similar cytotoxic capacity upon CD19+ target cells recognition as LV-engineered T-cells. We propose that NILV-S/MAR vectors are superior to current options for enabling long-term gene expression without the risk of insertional mutagenesis.

Citation Format: Chuan Jin, Mohanraj Ramachandran, Grammatiki Fotaki, Berith Nilsson, Magnus Essand, Di Yu. Long-term episomal gene transfer for safe engineering of T cells for adoptive cell therapy of cancer. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A171.

C-type natriuretic peptide signalling drives homeostatic effects in human chondrocytes

Signals induced by mechanical loading and C-type natriuretic peptide (CNP) represent chondroprotective routes that may potentially prevent osteoarthritis (OA). We examined whether CNP will reduce hyaluronan production and export via members of the multidrug resistance protein (MRP) and diminish pro-inflammatory effects in human chondrocytes. The presence of interleukin-1β (IL-1β) increased HA production and export via MRP5 that was reduced with CNP and/or loading. Treatment with IL-1β conditioned medium increased production of catabolic mediators and the response was reduced with the hyaluronan inhibitor, Pep-1. The induction of pro-inflammatory cytokines by the conditioned medium was reduced by CNP and/or Pep-1, αCD44 or αTLR4 in a cytokine-dependent manner, suggesting that the CNP pathway is protective and should be exploited further.

Antibacterial activity of various leaf extracts of Merremia emarginata

OBJECTIVE

To investigate the antibacterial activity and phytochemical screening of the aqueous, methanol and petroleum ether leaf extracts of Merremia emarginata (M. emarginata).

METHODS

The antibacterial activity of leaf extracts of M. emarginata were evaluated by agar well diffusion method against four selected bacterial species.

RESULTS

The presence of tannins, flavonoids, amino acids, starch, glycosides and carbohydrates in the different leaf extracts was established. The methanol extract was more effective against Bacillus cereus and Escherichia coli, whereas aqueous extract was more effective against Staphylococcus aureus and Pseudomonas aeruginosa.

CONCLUSIONS

: The results in the present study suggest that M. emarginata leaf can be used in treating diseases caused by the tested organisms.

Vector-encoded Helicobacter pylori neutrophil-activating protein promotes maturation of dendritic cells with Th1 polarization and improved migration

Helicobacter pylori neutrophil-activating protein (HP-NAP) is a major virulence factor involved in H. pylori infection. Both HP-NAP protein and oncolytic viruses encoding HP-NAP have been suggested as immunotherapeutic anticancer agents and adjuvants for vaccination but with little known about its mode of action to activate adaptive immunity. Dendritic cells (DCs) are key players in bridging innate and adaptive immune responses, and in this study we aim to evaluate the effect of HP-NAP on DC maturation, migration, and induction of adaptive immune response. Maturation markers CD83, CD80, CD86, HLA-DR, CD40, and CCR7 were upregulated on human DCs after treatment with supernatants from HP-NAP adenovirus-infected cells. HP-NAP-activated DCs had a Th1 cytokine secretion profile, with high IL-12 and relatively low IL-10 secretion, and migrated toward CCL19. Ag-specific T cells were efficiently expanded by Ag-presenting HP-NAP-activated DCs, which is an important property of functionally mature DCs. Furthermore, intradermal injections of HP-NAP-encoding adenovirus in C57BL/6 mice enhanced resident DC migration to draining lymph nodes, which was verified by imaging lymph nodes by two-photon microscopy and by phenotyping migrating cells by flow cytometry. In conclusion, therapeutic effects of HP-NAP are mediated by maturation of DCs and subsequent activation of Ag-specific T cells in addition to provoking innate immunity.