bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract A190: Mechanisms governing Foxp3-dependent and -independent gene expression in regulatory T-cells in evolutionary distant mice
Authors: Glasner Ariella , Zhong Yi , Veeken Joris Van Der , Rudensky Alexander
Published: February 2019

T regulatory (Treg) cells expressing the forkhead box transcription factor (Foxp3) are important regulators of immunity and play a key role in cancer and metastasis by controlling the activity of effector T-cells. Lineage-specifying transcription factors (TFs) establish cell identity and maintain cell specific transcriptional programs. Foxp3 is a key master TF controlling various Treg cell developmental and functional modalities. Foxp3 deficiency in humans and mice causes a life threatening autoimmune disease, and the enforced expression of Foxp3 in CD4+ T-cells confers suppressor functions. However, our understanding of Treg cell regulation during differentiation in the thymus, and in mature Treg cells in the periphery, whether Foxp3 dependent or independent, is still lacking. Single-nucleotide polymorphism (SNPs) may occur within coding genes or noncoding genomic regulatory areas and can have severe phenotypic consequences. We have recently attempted to link SNPs with differential Treg transcriptomic and epigenetic features in humans. However, such studies are limited by their intrinsic correlative nature, and by the limited number of SNPs. Here we use evolutionally distant mice strains C57Bl/6 (B6), CAST/EiJ (Cast) and SPRET/EiJ (Spret), to identify allele-specific imbalances and functional differences in the transcriptional and epigenetic programs during differentiation and in various conditions of Treg cells and their precursors. Using Foxp3 reporter and conditional knockout (KO) systems combined with interbreeding of the evolutionary distant mice strains in vivo, we explore the genetic and molecular mechanisms of Treg cell differentiation and function, employing high-throughput genomic methods including RNA-seq, ATAC-seq and Chip-seq. Such studies may pave a way for the development of novel therapeutic approaches to treat cancer and metastasis.

Citation Format: Ariella Glasner, Yi Zhong, Joris Van Der Veeken, Alexander Rudensky. Mechanisms governing Foxp3-dependent and -independent gene expression in regulatory T-cells in evolutionary distant mice [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 A190.
Abstract A201: Single-cell resolution profiling of tumor-reactive CD4 T-cells reveals immune landscape alterations
Authors: Magen Assaf , Nie Jia , Ciucci Thomas , Zhao Yongmei , Mehta Monika , Tran Bao , Hannenhalli Sridhar , Bosselut Rémy
Published: February 2019

T-cell responses to tumors are typically neutralized through a variety of mechanisms. While cytotoxic CD8 cells have been the focus of most efforts to exploit T-cell responses against tumors, recent studies have demonstrated the clinical potential of the CD4 tumor-infiltrating lymphocytes (TILs). However, the functional diversity characteristic of these cells has limited our ability to harness CD4 TILs to fight tumors. To address this issue, we have used new experimental strategies to characterize the heterogeneity of the antitumor CD4 response in vivo, combining (i) tracking of CD4 T-cells specific for a defined recombinant tumor antigen, both in the tumor microenvironment and draining lymph node (dLN), (ii) genome-wide mRNA sequencing at the single-cell level (scRNAseq) and (iii) new computational approaches to increase the resolution of subpopulations discovery and uncover robust transcriptional changes across populations. We find novel subpopulations of regulatory (Treg) and effector (Th1) TILs expressing diverse co-inhibitory gene programs unique to the tumor microenvironment. In contrast to TILs composition, we find an unexpected Follicular helper (Tfh)-like cells and non-classical Th1 response in dLN. Comparison of TIL subpopulations to those defined in an immune response to viral infection (LCMV) reveals gene expression patterns unique to cancer. Our study uncovers previously unknown CD4 T-cell effector programs that provide ineffective responses and fail to control tumor progression. Targeting these programs should provide new options for the design of improved immunotherapy strategies.

Citation Format: Assaf Magen, Jia Nie, Thomas Ciucci, Yongmei Zhao, Monika Mehta, Bao Tran, Sridhar Hannenhalli, Rémy Bosselut. Single-cell resolution profiling of tumor-reactive CD4 T-cells reveals immune landscape alterations [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 A201.
Abstract A205: Effects of anti-CTLA-4 and anti-PD-1 on memory T-cell differentiation and resistance to tumor relapse
Authors: Mok Stephen , Duffy Colm R. , Anang Nana-Ama A.S. , Allison James P.
Published: February 2019

Both anti-CTLA-4 and anti-PD-1 mediate significant response rates in cancer patients. As a hallmark of successful immunotherapies, they also mediate durable responses that last for years. For example, anti-CTLA-4 mediates a 22% 10-year overall survival rate, while anti-PD-1 mediates a 34% 5-year overall survival rate. Because of the broader uses of immunotherapies, the number of patients who have tumor relapse also increases. About 25% of patients who initially responded to anti-PD-1 have tumor relapse within 24 months. However, the relationship between tumor relapse and long-term effect of immunotherapies is still not clear. The goal of this study is to understand the differential effect of anti-CTLA-4 and anti-PD-1 on memory T-cell differentiation in murine tumor models. By rechallenging mice with tumor cells that have had tumors previously eradicated by either treatment, our results have shown that anti-CTLA-4 induces a more durable memory antitumor response compared to that treated with anti-PD-1. By tracing the antigen-specific CD8 T-cells throughout the memory phase, anti-CTLA-4 increases the frequency and cytokine production of antigen-specific T-cells compared with anti-PD-1. We have also found that anti-CTLA-4 induces the population of KLRG1+ effector CD8 T-cells among the effectors compared with anti-PD-1 during rechallenge, despite the ratio between central memory and effectors remaining the same. Our studies enable us to identify the long-term effect of immunotherapies on immune system.

Citation Format: Stephen Mok, Colm R. Duffy, Nana-Ama A.S. Anang, James P. Allison. Effects of anti-CTLA-4 and anti-PD-1 on memory T-cell differentiation and resistance to tumor relapse [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 A205.
Abstract A213: Exploit the zebrafish to study lymphocyte infiltration in MYCN-amplified neuroblastoma
Authors: Qin Xiaodan , Lam Andrew , Feng Hui
Published: February 2019

Neuroblastoma is one of the most common pediatric solid tumors that derives from sympathetic nerve ganglia. Children with MYCN-amplified tumors have a very poor prognosis. MYCN amplification is associated with impaired inflammatory profiles and reduced numbers of tumor-infiltrating cytotoxic T-lymphocytes (CTL). However, it remains elusive how MYCN blocks the trafficking of T-cells to tumors and protects tumor cells escaping from CTL-mediated cytotoxicity. Elucidation of the mechanism by which MYCN suppresses immune surveillance in the neuroblastoma microenvironment could lead to improved treatment outcomes through immunotherapy. We generated a zebrafish model, in which lymphocytes and tumor cells were differentially labeled with red and green fluorochromes. We monitored these fish for trafficking of mCherry-labeled lymphocytes to EGFP-positive MYCN-overexpressing premalignant neural crests on 5, 14, and 21 days post fertilization (dpf). We found that MYCN-overexpressing premalignant neural crests could attract lymphocytes in living fish. To observe lymphocyte infiltration in different stages of tumor development, we will perform cryosection and quantify lymphocyte infiltration in each stage of tumor development. While this zebrafish model is useful in studying the behaviors of immune cells at different stages of tumor development, it can be further exploited to understand how MYCN regulates immune escape and how immune cell infiltration can be enhanced in MYCN-amplified neuroblastoma to suppress tumor onset and progression. This knowledge is critical for development of more efficient immunotherapies in treating children with neuroblastoma.

Citation Format: Xiaodan Qin, Andrew Lam, Hui Feng. Exploit the zebrafish to study lymphocyte infiltration in MYCN-amplified neuroblastoma [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 A213.
Abstract A219: Using poxvirus to improve immunotherapy for brain glioma
Authors: Tang Bingtao , Schane Claire , Shisler Joanna , Roy Edward
Published: February 2019

Oncolytic viral immunotherapy is a novel approach to cancer treatment. Viruses can directly kill cancer cells, provide antigens to dendritic cells to stimulate a T-cell response, and make cancer cells express genes of immune-enhancing cytokines locally within the tumor microenvironment. We used two types of poxvirus, myxoma virus and vvDD vaccinia virus (double deletion of vaccinia growth factor and thymidine kinase), to deliver IL-15/IL-15Rα gene (a cytokine that boosts the immune system) into brain gliomas. We found that the numbers of NK cells and CD8+ T-cells in the tumor area greatly increased and viable cancer cells substantially decreased after the injection of vvDD-IL15/IL15Rα virus. Vaccination of GARC-1 (a neoantigen for mouse glioma) with CpG and Incomplete Freund’s Adjuvant twice before tumor implantation together with vvDD-IL15/IL15Rα virus, rapamycin and celecoxib treatment after tumor implantation eliminated the gliomas. In order to mimic the clinical situation of treatment beginning after establishment of the tumor, GARC-1 specific CD8+ T-cells were adoptively transferred into tumor-bearing mice; when combined with oncolytic poxvirus (either Myx-IL15/IL15Rα or vvDD-IL15/IL15Rα), rapamycin, and celecoxib, this treatment can also cure gliomas. We already confirmed that IL15/IL15Rα, adoptive transfer of GARC-1 specific T-cells and celecoxib are essential components in this combination treatment. Current studies are evaluating the mechanism and contributions of different components of the treatment.

Citation Format: Bingtao Tang, Claire Schane, Joanna Shisler, Edward Roy. Using poxvirus to improve immunotherapy for brain glioma [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 A219.
Abstract B001: Generation of ImmTACTM molecules: Engineering high-affinity soluble T-cell receptors for the treatment of cancer
Authors: Bombik Izabela , Bortoluzzi Alessio , Mai Nicole , Preston Andrew , Vuidepot Annelise , Jakobsen Bent K. , Liddy Nathaniel
Published: February 2019

Immunotherapeutic strategies are centered on harnessing the human immune system to recognise and destroy cancer cells. At Immunocore, we have developed bi-specific Immune-mobilising monoclonal TCRs Against Cancer (ImmTAC) molecules comprising a soluble TCR fused to an anti-CD3 effector function that redirect T-cells to destroy cancer cells. The TCR-targeting domain overcomes a key limitation of traditional antibody-based therapies by targeting short peptide fragments derived from intracellularly processed proteins presented on the cell surface by human leukocyte antigens (HLAs), offering up to nine-fold more potential targets than are accessible to antibodies. To mediate efficient T-cell-mediated tumor clearance, ImmTAC molecules are engineered to overcome the weak affinities of natural TCRs imposed by thymic selection through a complex multistep engineering process described herein.T-cell clones recognising in-house validated cancer-specific peptides are isolated and affinity-enhanced up to a million fold by introducing mutations to the complementarity determining regions, resulting in picomolar affinity TCRs capable of recognizing exceptionally low numbers of target on the cancer cell surface. The TCR is fused to an anti-CD3 scFv to generate an ImmTAC molecule and is made soluble through the inclusion of a non-native disulphide bond. The efficacy and specificity of the ImmTAC molecule is scrutinized using a range of cellular and molecular assays. The potential application of the ImmTAC platform is exemplified by the expanding portfolio of ImmTAC molecules targeting diverse disease indications. Our lead candidate, IMCgp100, recognizes the melanoma-associated gp100 peptide and is in pivotal trials for the treatment of patients with metastatic uveal melanoma.

Citation Format: Izabela Bombik, Alessio Bortoluzzi, Nicole Mai, Andrew Preston, Annelise Vuidepot, Bent K. Jakobsen, Nathaniel Liddy. Generation of ImmTACTM molecules: Engineering high-affinity soluble T-cell receptors for the treatment of cancer [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 B001.
Abstract B011: Inhibition of G9a reestablishes the MHC class I loss due to EMT in lung cancer cells
Authors: Fukumasu Heidge , Pires Pedro R.L. , Xavier Pedro L.P.
Published: February 2019

The epithelial-to-mesenchymal transition (EMT) is an important phenotype for cancer cells to invade and metastasizes. In addition, cancer cells should escape from the immune system during malignant progression. Here, we aimed to demonstrate the potential of G9a inhibition of EMT in cancer cells and most importantly, the reestablishment of MHC class I expression (MHC-I), one of the important factors associated with the loss of antigenicity of cancer cells. The lung epithelial cancer cell line A549 was cultured under controlled conditions in RPMI culture media supplemented with 10% of bovine fetal serum (BFS), 1% of antibiotics (penicillin and streptomycin), 2% of glutamine in incubator at 37oC and air atmosphere containing 5% of CO2. The tumor growth factor beta (TGFb) exposure for 5 days was used to induce EMT. In addition, another group of A549 cells received TGFb plus the UNC0368 an G9a (a histone methyl transferase) inhibitor for 5 days. Then, cells were evaluated for acquiring mesenchymal cell morphology and MHC-I gene expression (relative quantification). After 5 days, A549 cells exposed to TGFb clearly have gone through EMT by changing their morphology to a fibroblast-like phenotype. Also, the MHC-I gene expression decreased significantly (p=0.0036) after EMT. The G9a inhibitor partially impeded the EMT induced changes in morphology of A549 cells and reestablished the MHC-I gene expression to the control level. In conclusion, G9a inhibition seemed a promising therapeutic target to improve the efficacy of immunotherapies depending on neoantigen expression by cancer cells. However, more studies are necessary and are under way in our laboratory.

Citation Format: Heidge Fukumasu, Pedro R.L. Pires, Pedro L.P. Xavier. Inhibition of G9a reestablishes the MHC class I loss due to EMT in lung cancer 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 B011.
Abstract B014: T-cell Elispot Proficiency Panel 2017/2018: Evaluating routine T-cell Elispot assays
Authors: Haley Stephen T. , Halgreen Charlotte , Frederiksen Katrine , Brogaard Rikke , Brix Liselotte
Published: February 2019

Monitoring antigen-specific T-cell responses is becoming increasingly important in Immunotherapeutic research and development. Thanks to the harmonization efforts by the CIC and CIMT over many years, and the development of better reagents and protocols, MHC multimer and T-cell Elispot assays are now more reliable and accurate assays for monitoring antigen-specific T-cell immunity. Supported by CIMT and CIC, Immudex has conducted a T-cell Elispot proficiency panel Winter 2017/2018 to evaluate assay performance in immune monitoring laboratories routinely doing T-cell Elispot assays. 39 worldwide participants received two cell samples, together representing low, medium and high responses for two predefined peptide pools. A negative control reagent was also included. Participants were asked to use the Direct Human IFNγ Elispot Assay to determine spot count corresponding to each of the predefined peptide pools and the negative control reagent. After performing the Direct Human IFNγ Elispot Assay, the participants report back their results for each cell sample as “number of spots per 200.000 viable cells” for each of the predefined peptide pools and negative control reagent. The data set was analyzed, and each participating laboratory received a report detailing the individual laboratory’s performance (in an anonymized format). The anonymized report was publicly available April 2018, and data will be presented at the CRI-CIMT-EATI-AACR Fourth International Cancer Immunotherapy Conference.

Citation Format: Stephen T. Haley, Charlotte Halgreen, Katrine Frederiksen, Rikke Brogaard, Liselotte Brix. T-cell Elispot Proficiency Panel 2017/2018: Evaluating routine T-cell Elispot assays [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 B014.
Abstract B030: Predicting the response of uveal melanoma to immunotherapy with MRI assessments
Authors: Moreira Alvaro , Saake Marc , Schuler Gerold , Heinzerling Lucie
Published: February 2019

Purpose: Contrary to cutaneous melanoma, uveal melanoma is little responsive to immune checkpoint inhibitors. This is thought to result from a different immunogenicity of these two melanoma variants. We sought to investigate whether imaging properties in magnetic resonance imaging (MRI) were able to predict the response of liver metastases of uveal melanoma to immune checkpoint blockade. Study Design: Pre- and post-therapeutic liver MRIs, including a native T1-weighted fat-saturated FLASH sequence, were analyzed in a population of patients with uveal melanoma, segmenting the metastasis into areas of active tumor, necrosis and edema. Different lesions from all of the patients were investigated and their patterns correlated with response to immunotherapy. Results: Contrary to previous results of other research groups, MRI signal intensity scores in our population could not predict response to immunotherapy. Therefore, we could not validate the MRI assessment as a clinical biomarker. Other parameters need to be integrated in the radiomic signature. Conclusions: Current MRI imaging methods are limited in their ability to predict response of liver metastases of uveal melanoma to immune checkpoint blockade. Advanced MRI imaging methods, more sensitized to different biophysical processes including blood perfusion and tumor metabolism, which can provide more specific information on tissue physiology, should be investigated in the light of emerging immunotherapies for uveal melanoma, such as tumor-infiltrating lymphocytes and recent developments in dendritic cell cancer vaccines.

Citation Format: Alvaro Moreira, Marc Saake, Gerold Schuler, Lucie Heinzerling. Predicting the response of uveal melanoma to immunotherapy with MRI assessments [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 B030.
Abstract B033: T-cell-induced tumor vulnerability discovery in an IFNγ-independent genomic landscape
Authors: Peeper Daniel S. , Vredevoogd David , Kuilman Thomas
Published: February 2019

New clinical opportunities are needed to increase immunotherapy (IT) benefit. Whereas IFNγ-pathway mutations cause IT resistance, we find that IFNγ receptor-deficient tumors remain remarkably susceptible to T-cell elimination. By integrating transcriptomics, proteomics and genome-wide CRISPR-Cas9 screening with clinical data, we defined the IFNγ-independent tumor landscape and uncovered an immunotherapeutic opportunity. Ablation of TRAF2 enhanced T-cell elimination of both melanoma and lung cancer cells by redirecting TNF signaling to favor RIPK1-dependent apoptosis. TRAF2 loss greatly enhanced the therapeutic potential of pharmacologic inhibition of its interaction partner cIAP. Corroborating these observations clinically, we identified recurring TRAF2 mutations that reduced T-cell sensitivity of tumor cells. Furthermore, both IT response duration and overall survival were lower for tumors that had acquired TNF pathway mutations on IT, suggesting immune-editing by TNF pressure. These results functionally annotate the tumor genome landscape of IFNγ-independent T-cell cytotoxicity, and merit clinical exploration of TRAF2 for cancer immunotherapy.

Citation Format: Daniel S. Peeper, David Vredevoogd, Thomas Kuilman. T-cell-induced tumor vulnerability discovery in an IFNγ-independent genomic landscape [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 B033.
Abstract B040: Electrospun implantable anticancer device comprising immune adjuvant photo-responsive nanoparticles with checkpoint blockade for effective cancer therapy
Authors: Unnithan Afeesh Rajan , Sasikala Arathyram Ramachandra Kururp , Park Chan Hee , Kim Cheol Sang
Published: February 2019

An implantable anticancer device (IAD) that can eradicate local regional breast cancer recurrence (LRR), inhibit metastasis as well as to enhance the breast reconstruction during/after therapy is proposed. The IAD is developed by combining nanofiber-based chemo-photothermal therapy platform with check point blockade immunotherapy. Here we developed a coreshell electrospun nanofiber encapsulated with drug conjugated MoS2 as chemo-photothermal agent along with imiquimod as an immune response modifier. The near-infrared laser exposure to IADs can generate tumor-associated antigens from primary tumors, which in the presence of released imiquimod from IADs can show vaccine-like functions. Moreover, the nanofiber matrix will enable the sustained and tumor-specific anticancer drug release with a minimum initial burst release and the repeated photothermal capability to ensure the synergistic inhibition of tumor recurrence. In addition to that, the checkpoint-blockade using anti-cytotoxic T-lymphocyte antigen-4 (CTLA4) in combination with the generated immunologic responses will be able to attack remaining tumor cells causing metastasis inhibition with strong immunologic memory effect, which can shield against the tumor recurrence after the post elimination of initial tumors. The IAD nanofiber morphology resembles the extra cellular matrix (ECM) enrich the reconstruction of poor breast cosmesis resulted from the surgical treatment, by supporting the lipofilling of the surgical residual cavity to induce the adipogenic process. So, in this work we propose that the tumor associated antigens created in situ after photothermal therapy by the immune adjuvant nanofiber IAD could show vaccine-like functions, which in combination with checkpoint blockade show strong antitumor immune responses for effective cancer immunotherapy as a potential platform for synergistic inhibition of LRR and a great promise for the in situ breast reconstruction ability for better breast cosmesis.

Citation Format: Afeesh Rajan Unnithan, Arathyram Ramachandra Kururp Sasikala, Chan Hee Park, Cheol Sang Kim. Electrospun implantable anticancer device comprising immune adjuvant photo-responsive nanoparticles with checkpoint blockade for effective cancer therapy [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 B040.
Abstract B043: Enhanced T-cell immunity in vivo using injectable bioengineered scaffolds
Authors: Shah Nisarg , Mooney David J.
Published: February 2019

Hematopoietic stem cell transplantation (HSCT) is a potentially curative therapy for hematological malignancies and immunologic disorders, but allogeneic HSCT is limited by deficiency and dysregulation of T-cells. We aimed to enhance post-HSCT T-cell reconstitution and hypothesized that a T-cell lymphopoietic bone marrow niche might be engineered to foster production of T-cell progenitors in vivo, which can undergo host-driven selection. To test this hypothesis, we created an injectable biomaterial-based scaffold that promotes T-cell development in vivo by recapitulating key features of the bone marrow niche. The composite device, referred to as a bone marrow cryogel (BMC), is comprised of a macroporous hydrogel-based scaffold permitting cellular infiltration. The presentation of T-lineage cues in a bone marrow-like microenvironment enhanced thymic seeding of progenitors and facilitated the enhancement of donor T-cell reconstitution after HSCT in mice. The BMC-reconstituted T-cells were functional, with a diverse T-cell receptor repertoire and modulated GVHD. BMC may represent a simple to administer, off-the-shelf approach to post-HSCT T-cell regeneration.

Citation Format: Nisarg Shah, David J. Mooney. Enhanced T-cell immunity in vivo using injectable bioengineered scaffolds [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 B043.
Abstract B052: Immunotherapy for melanoma by adenovirus-mediated full-length antibody, nivolumab
Authors: Wang Xuchen
Published: February 2019

Nivolumab, a fully human, IgG4 immune checkpoint inhibitor antibody, binds PD-1 on activated immune cells to disrupt PD-1 interaction with PD-L1 and PD-L2 ligands, thereby attenuating inhibitory signals and augmenting the host antitumour response. In 2014, nivolumab was approved by FDA and has been used to treat various types of cancer such as melanoma, non-small cell lung cancer, renal cell carcinoma, and classic Hodgkin's lymphoma. However, due to the high price of nivolumab and the long cycle of treatment, many patients cannot afford and receive adequate treatment. Here, we generated a new, cheaper form of nivolumab for cancer immunotherapy, by cloning the full-length nivolumab antibody gene into two serotypes of adenovirus vectors, termed as AdHu5-Nivo and AdC68-Nivo. Ad vectors based on human serotype 5 (AdHu5) have been proved in a lot of previous studies to be safe and efficient. Compared with AdHu5, chimpanzee Ads exhibit much lower seroprevalence in human beings, which made them great alternative Ad gene vector. Until now, we have detected a high expression of nivolumab in vitro by Western blot and sandwich ELISA. In vivo studies showed that a single dose of AdHu5-Nivo or AdC68-Nivo can induce sustained nivolumab expression. The biologic activities of the two mAbs are analogous compared with commercial monoclonal antibody. To follow up we will verify their antitumor effects on both cellular level and melanoma transplant animal models.

Citation Format: Xuchen Wang. Immunotherapy for melanoma by adenovirus-mediated full-length antibody, nivolumab [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 B052.
Abstract B058: Rapid and controlled T-cell expansion using scaffolds that mimic antigen-presenting cells
Authors: Zhang David K.Y. , Vaynrub Anna , Mooney David J.
Published: February 2019

Current approaches to expand T-cells ex vivo for therapeutic applications are limited by low expansion rates and often result in unpredictable expansion products of varying phenotype and function. Key attributes, such as a balanced ratio of CD4-to-CD8 T-cells, or a high central memory T-cell fraction are known to correlate with robust and durable therapeutic responses but remain difficult to reproducibly achieve. Strategies that allow one to precisely control the phenotype of expanded T-cell products may thus potentiate the effects of CAR-T-cell therapies, and understanding how T-cells respond to stimulation is a crucial step to this end. Recently, we described a 3D expansion system that mimics natural antigen presenting cells (APCs) and promotes greater polyclonal expansion of primary human T-cells than commercial expansion beads (Dynabeads). These biodegradable, APC-mimetic scaffolds (APC-ms) are composed of fluid lipid bilayers supported on mesoporous silica micro-rods, which enables precise control over the spatial organization of membrane-bound T-cell receptor (TCR) stimulatory and costimulatory cues (i.e., anti-CD3/anti-CD28). Here, we investigated the activation and memory signature of primary human T-cells over time in response to APC-ms with different densities of activating surface cues compared to Dynabead stimulation. Higher surface cue densities of anti-CD3/anti-CD28 promoted greater proportions of central memory T-cells, with a parallel increase in the CD4-to-CD8 T-cell ratio. T-cells stimulated with Dynabeads exhibited higher expression of CD25 and CD69 that peaked earlier than standard APC-ms formulations, suggesting that APC-ms promotes relatively more transient T-cell activation than Dynabeads, potentially mitigating overstimulation and exhaustion. Overall, these data demonstrate that APC-ms can be used to rapidly expand primary human T-cells and tune their phenotypic attributes (e.g., CD4-to-CD8 ratio and memory subpopulations). This technology has the potential to improve the production of T-cells for adoptive T-cell-based therapies.

Citation Format: David K.Y. Zhang, Anna Vaynrub, David J. Mooney. Rapid and controlled T-cell expansion using scaffolds that mimic antigen-presenting 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 B058.
Abstract B062: Investigate the role of T lymphocytes in the regulation of energy expenditure and obesity
Authors: Hu Bo , Jin Chengcheng , Zeng Xing , Jedrychowski Mark , Zhao Chen , Banks Alex , Gigi Steven , Mathis Diane , Spiegelman Bruce
Published: February 2019

The increasing incidence of obesity and its co-morbid conditions poses a great challenge to global health. It is becoming clear that obesity is associated not only with type 2 diabetes mellitus and cardiovascular disease, but also with multiple types of cancer. Obesity and its associated inflammatory response has been closely linked to many aspects of cancer biology, including tumorigenesis, cancer immunotherapy and cancer cachexia. Obesity is caused by energy surplus when energy intake exceeds energy expenditure. As an important contributor of total energy expenditure is adaptive thermogenesis in brown adipose tissue, a promising and emerging avenue for obesity treatment is to increase energy expenditure by augmenting the activity of thermogenic adipocytes. Emerging evidence indicates that the immune system is instrumental in the control of host energy metabolism. However, the underlying mechanism has not been fully understood; specifically, the role of T-cells in regulating host thermogenesis has not been well studied. Here we identified that gamma delta T-cells and their associated signaling play a critical role in mediating adaptive thermogenesis in response to cold exposure in brown adipose tissue and high-fat-diet-induced obesity. In pursuing these studies we hope to discover new ways (targeting immune cells) to support the obesity treatment and reduce obesity-associated systemic inflammation and complications, especially cancer.

Citation Format: Bo Hu, Chengcheng Jin, Xing Zeng, Mark Jedrychowski, Chen Zhao, Alex Banks, Steven Gigi, Diane Mathis, Bruce Spiegelman. Investigate the role of T lymphocytes in the regulation of energy expenditure and obesity [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 B062.
Abstract B064: Chemical biology studies of anti-inflammatory lipids
Authors: Li Qiang , Hang Howard
Published: February 2019

A number of endogenous polyunsaturated fatty acids (PUFAs), including lipoxins, resolvins and protectins can help resolve inflammation and prevent various diseases. The beneficial effects in human health of these anti-inflammatory lipids have long been recognized, but their mechanism(s) of action and precise protein targets have remained unclear. Peroxisome proliferator-activated receptor γ (PPARγ) which is a ligand activated transcription factor and has been proposed to sense unsaturated and oxidized fatty acids may serve as a candidate target of these anti-inflammatory lipids. To address these questions, I have completed the total synthesis of anti-inflammatory lipid protectin D1 (PD1) by utilizing a convergent strategy. PPARγ-transactivation assay indicates that our synthetic PD1 potently activates PPARγ. I also evaluated the biochemical interactions of PD1 with PPARγ in cells using competitive photoaffinity labeling with a bifunctional fatty acid reporter (x-alk-16). Notably, over-expressed PPARγ can be crosslinked by x-alk-16 in a UV- and dose-dependent manner both in vitro and in mammalian cells. To further expand its application for endogenous PPARγ, I evaluated A549 cells and HT-29 cells, which also showed excellent x-alk-16 crosslinking of endogenous PPARγ both in vitro and in mammalian cells. These findings indicate that x-alk-16 can serve as a suitable photoaffinity fatty acid reporter to study PPARγ. By utilizing this chemical tool, the interaction of any bioactive small molecules with PPARγ can be evaluated. Several PPARγ synthetic ligands, including nTZDpa and rosiglitazone are chosen as a showcase for this study because they show very high affinity to PPARγ. These PPARγ synthetic ligands can compete the interaction between x-alk-16 and PPARγ. When applying PD1 as competitor, obvious competition effect can be observed, which suggests that PPARγ is one of the major protein targets of PD1. By performing unbiased chemical proteomic analysis, several unpredicted protein targets of PD1 were also identified and are currently being evaluated. Our findings should improve the current understanding of anti-inflammatory lipids targets and help elucidate the key pathways to improve the resolution of inflammation.

Citation Format: Qiang Li, Howard Hang. Chemical biology studies of anti-inflammatory lipids [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 B064.
Abstract B066: Identifying novel effectors of the gut microbiota that modulate cancer cell killing by CTLs using functional metagenomics
Authors: Lobel Lior , Garrett Wendy S.
Published: February 2019

The immune system, which is profoundly affected by the microbiota composition and activity, plays an anti-tumorigenic role by surveying for and killing cancer cells. Indeed, recent studies found the microbiota to be essential for the success of cancer immunotherapy treatments in mice, while the bacterial effectors remain unknown. We developed an innovative high throughput screening system to isolate microbiota-derived effectors that modulate the ability of immune cells to kill cancer cells. We utilize the mouse CT26 colon carcinoma cell line as targeT-cells and the GSW11 specific CCD2Z T-cell hybridoma cell line as the effector cells. Bacterial DNA extracted from fecal contents of mice bearing colorectal tumors served for generation of metagenomics libraries. Supernatnants of the metagenomic clones were added to the CT26-CCD2Z co-culture and CCD2Z activation was measured using a LacZ reporter, regulated by NFAT. We identified about 40 clones that activate CCD2Z cells. We performed secondary screens and tested the activation of CD8+ T-cells sorted from mouse spleens. We sequenced the metagenomic DNA of several clones and analyzed the coding sequences. Currently, we are sub-cloning the clones to find the microbial genes responsible for CD8+ T-cell activation and design strategies for isolation of active molecules from these bacterial supernatnats. Finally, we hope that our future results could be taken to the clinic and serve for diagnosis, prognosis and therapeutics.

Citation Format: Lior Lobel, Wendy S. Garrett. Identifying novel effectors of the gut microbiota that modulate cancer cell killing by CTLs using functional metagenomics [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 B066.
Abstract B070: Neoepitope and mutation load as a biomarker in a broad cohort of cancer patients treated with immunotherapy
Authors: Bjerregaard Anne-Mette , Lima Vinicius Araujo Barbosa de , Borch Annie , Oestrup Olga Araujo Barbosa de , Lassen Ulrik , Hadrup Sine Reker
Published: February 2019

Various different treatments of immunotherapy have in recent years made their mark in mainstream oncology, but it is still uncertain which patients will benefit and why. To determine this, different biomarkers have been investigated including tumor specific peptides originating from somatic mutations and recognized by T-cells, neoepitopes. Recent studies show that clinical benefit of immunotherapy correlate with both high mutational burden and high neoantigen load in defined patient groups, melanoma and lung cancer, underlining the possibility to use these measurements as biomarkers, and driving the hypothesis that neoantigen-responsive T-cells are the main drivers to cancer-cell elimination. We propose to investigate if a high mutational load and a high amount of neoepitopes are correlated with a general respond to immunotherapy across different cancer types and immunotherapy treatments. To examine this correlation, we studied 19 patients who have been treated with different kinds of immunotherapy. The data consist of Whole Exome Sequencing (WXS) data from blood and tumor, as well as tumor mRNA sequencing from all patients. Neoepitope load was predicted using Mutant peptide extractor and informer (MuPeXI) to find possible neoepitopes and score the neopeptides by their potential immunogenicity. The analysis of the sequencing data from the 19 patients revealed that even though these patients have cancers of varying origin and treated with different immunotherapies, a significant correlation was observed between a high number of neoepitopes as well as high mutational load with an increased possibility of a clinical benefit to immunotherapy. These findings showed that overall a clinical benefit is correlated with increased mutational load and neoepitopes independent of the cancer type and treatment which if used as a biomarker can possibly stratify patients determining who is likely to respond to cancer immunotherapy. Furthermore, we examined the tumor mRNA for T-cell recpetor sequences, and interestingly patients with high level of predeicted neoepitopes show enhanced oligoclonality of TCRs at the tumor site.

Citation Format: Anne-Mette Bjerregaard, Vinicius Araujo Barbosa de Lima, Annie Borch, Olga Araujo Barbosa de Oestrup, Ulrik Lassen, Sine Reker Hadrup. Neoepitope and mutation load as a biomarker in a broad cohort of cancer patients treated with 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 B070.
Abstract B080: Improved neoantigen vaccine selection by combining prediction of pMHC presentation and T-cell epitopes
Authors: Kodysh Julia , O'Donnell Tim , Blazquez Ana B. , Finnigan John , Bhardwaj Nina , Rubinsteyn Alex
Published: February 2019

The OpenVax group has helped initiate two neoantigen vaccine clinical trials (NCT02721043, NCT02721043) at Mount Sinai based on a simple multiplicative ranking criterion which assigns equal weight to expression and predicted Class I MHC binding affinity of mutated peptides (1). This poster seeks to better ground our ranking method for selecting the contents of neoantigen vaccines in several sources of immunological data. We built a better model of MHC-I presentation on the cell surface by relating RNA expression and MHC affinity to pMHC ligands identified with mass spectrometry (2). Secondly, we trained a model of overall T-cell immunogenicity whose primary input is the predicted pMHC presentation score of any peptide-MHC combination, alongside other features such as similarity to the self proteome. This model is trained on T-cell response data deposited in the Immune Epitope Database (3). Lastly, we assembled a small dataset of peptide sequences used in neoantigen vaccine trials (1,4,5), which are labeled by whether they achieved a CD8+ or CD4+ T-cell response. This dataset allows us to explore several hypotheses about the relationship between immunogenic response and sequence similarity to both the self proteome and pathogenic proteomes. References: 1. Rubinsteyn A, Kodysh J, …, Hammerbacher J. Computational pipeline for the PGV-001 Neoantigen Vaccine Trial. Frontiers in Immunology 2018. 2. Abelin JG, Keskin DB,..., Wu CJ. Mass spectrometry profiling of HLA-associated peptidomes in mono-allelic cells enables more accurate epitope prediction. Immunity 2017. 3. Vita R, Overton JA, …, Peters B. The immune epitope database (IEDB) 3.0. Nucleic Acids Res 2014. [4. Sahin U, Derhovanessian E, …, Türeci Ö. Personalized RNA mutanome vaccines mobilize poly-specific therapeutic immunity against cancer. Nature 2017. 5. Ott P, Hu Z, …, Wu CJ. An immunogenic personal neoantigen vaccine for patients with melanoma. Nature 2017.

Citation Format: Julia Kodysh, Tim O'Donnell, Ana B. Blazquez, John Finnigan, Nina Bhardwaj, Alex Rubinsteyn. Improved neoantigen vaccine selection by combining prediction of pMHC presentation and T-cell epitopes [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 B080.
Abstract B103: Altering the mevalonate pathway to enhance CD8+ T-cell responses
Authors: Burn Olivia K. , Authier-Hall Astrid , Brooks Collin , Anderson Regan , Marshall Andrew , Painter Gavin , Weinkove Robert , Hermans Ian
Published: February 2019

Inhibitors of the mevalonate pathway have been found to induce inflammatory reactions and delay the progression of cancer. Emerging evidence suggests these inhibitors sensitise immune cells to signalling from the myeloid differentiation primary response gene 88 (MyD88) and in turn enhance NF-κB dependent activation of antigen presenting cells (APCs), an essential element in inducing an immune response. To further explore the adjuvant effect of these inhibitors, we designed a vaccine comprising an inhibitor of the mevalonate pathway conjugated to a tumor-specific peptide. We hypothesized that immunisation with these vaccines would elicit functional peptide-specific CD8+ T-cells. Using an in vivo mouse model, we found the vaccine generates greater peptide-specific cytotoxicity against targeT-cells bearing a human papillomavirus antigen than its unconjugated components, a chemical control vaccine or peptide alone. Moreover, the vaccine delayed outgrowth of an antigen-expressing tumor. Using human PBMCs, we obtained preliminary evidence that a similar vaccine can promote greater in vitro activation of CD8+ T-cells specific for a cytomegalovirus antigen than peptide alone. These results suggest that inhibitors of the mevalonate pathway can act as adjuvants in eliciting cytotoxic T-cell responses, and may have utility for the treatment or prevention of viral infections or neoplasia.

Citation Format: Olivia K. Burn, Astrid Authier-Hall, Collin Brooks, Regan Anderson, Andrew Marshall, Gavin Painter, Robert Weinkove, Ian Hermans. Altering the mevalonate pathway to enhance CD8+ T-cell responses [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 B103.
Abstract B105: A cancer vaccine targeting many neoantigens is required for effective eradication of large tumors
Authors: D'Alise Anna Morena , Leoni Guido , Cotugno Gabriella , Troise Fulvia , Langone Francesca , Fichera Imma , Lucia Maria De , Vitale Rosa , Leuzzi Adriano , Bignone Veronica , Matteo Elena Di , Tucci Fabio Giovanni , Avalle Lidia , Poli Valeria , Lahm Armin , Catanese Maria Teresa , Folgori Antonella , Colloca Stefano , Nicosia Alfredo , Scarselli Elisa
Published: February 2019

Cancer neoantigens (nAgs) have the potential to elicit strong and tumor-specific immune responses and are, therefore, of great interest for cancer immunotherapeutic strategies, including therapeutic vaccines. Here we developed a novel neoantigen cancer vaccine based on adenoviruses derived from non-human Great Apes (GAds). GAds vaccination was highly effective in prophylactic or early therapeutic treatment of mouse tumors, independently of the number of encoded nAgs. In presence of high tumor burden, GAd has no antitumor effect unless combined with anti-PD1 treatment. In this more stringent setting, effectiveness of vaccination required the targeting of many neoantigens. Analysis of gene expression profile of tumors from responder mice showed greater diversification of the T cell repertoire with increased number of clonotypes in combo treated animals compared to anti-PD-1. Data suggest that GAd vaccines encoding a large number of nAgs can synergize with checkpoint inhibitors therapy by increasing the breadth of nAgs-specific T cells.

Citation Format: Anna Morena D'Alise, Guido Leoni, Gabriella Cotugno, Fulvia Troise, Francesca Langone, Imma Fichera, Maria De Lucia, Rosa Vitale, Adriano Leuzzi, Veronica Bignone, Elena Di Matteo, Fabio Giovanni Tucci, Lidia Avalle, Valeria Poli, Armin Lahm, Maria Teresa Catanese, Antonella Folgori, Stefano Colloca, Alfredo Nicosia, Elisa Scarselli. A cancer vaccine targeting many neoantigens is required for effective eradication of large tumors [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 B105.