bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3975: A therapeutic screening platform for assessing antigen-specific T cell-mediated tumor killing in vitro
Authors: Klaver Elsenoor , Leonard Henry , Lieverse Elizabeth , Brand Oliver , Reelfs Olivier , Kirkham Christopher , Schewitz-Bowers Lauren , Brackenbury Louise 
Published: March 2024

Abstract
Many cancers remain resistant to conventional therapies, consequently there has been an exponential rise in the number of therapeutics harnessing the power of the immune system in an oncology setting, with several remarkable examples of success. High frequencies of infiltrating tumor-specific T cells have been linked to improved patient outcomes, which highlights the importance of uncovering how therapeutics can enhance their function. To explore this functionality in a preclinical setting it is critical to have physiologically relevant models. Here, we demonstrate that common issues, such as low precursor frequencies and restricted HLA-types can be overcome via access to HLA-typed samples and use of expansion platforms which attain high numbers of antigen-specific T cells. Furthermore, we show how these systems enable vaccine immunogenicity screening and assessment of therapeutic efficacy. Healthy blood donations were screened for HLA type and antigen-specific T cells were expanded by either co-culture with peptide-pulsed dendritic cells or polyclonal stimulation following multimer enrichment and FACS sorting. Following expansion, the large number of antigen-specific T cells generated enabled the T cells to be assessed via phenotyping, cytokine secretion, or functional killing assays in a 2D or 3D tumor setting. Tumor targets with either 1) endogenous antigen expression, 2) antigen introduced via lentiviral overexpression or 3) peptide loading of MHC class I were utilized. Validated readouts for measuring antigen-specific killing included flow cytometry and time-lapse imaging (IncuCyte), alongside quantification of antigen-specific IFNɣ responses by ELISpot. These pre-clinical platforms represent a suite of physiologically relevant T cell assays which can be used to perform candidate selection in tumor associated antigen/neoantigen vaccine drug development programs, pharmacological inhibition of checkpoint pathways, or co-stimulatory agonist discovery. In combinatorial approaches with radio- or chemotherapy, the development of novel immunotherapies offers hope to many patients with treatment-resistant cancers.
Citation Format: Elsenoor Klaver, Henry Leonard, Elizabeth Lieverse, Oliver Brand, Olivier Reelfs, Christopher Kirkham, Lauren Schewitz-Bowers, Louise Brackenbury. A therapeutic screening platform for assessing antigen-specific T cell-mediated tumor killing in vitro [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3975.
Abstract 3980: Investigating the role of host obesity in promoting immunotherapy resistance
Authors: Ogbonna Henry Nnaemeka , Roberts Zachary , Kvarnberg Haley , Dempsey Francesca , Song Patrick N. , Sorace Anna G. , Norian Lyse 
Published: March 2024

Abstract
Obesity is linked to an increased risk of various cancers, including renal cell carcinoma (RCC). Many RCC patients have obesity at diagnosis and treatment initiation, and our lab has found that this significantly impairs immunotherapy outcomes. Both preclinical and clinical reports, from our lab and others, have demonstrated that obesity reduces the efficacy of CD8+ T cell-dependent immunotherapy by increasing pro-tumorigenic IL-1β. Combining anti-PD-1 based therapy with anti-IL-1β triggers the recruitment of CD8+ T cells and improves the efficacy of anti-PD-1 based immunotherapy. However, the mechanistic links between obesity and increased IL-1β production remains unknown. Our objective is to identify mechanisms promoting IL-1 β-driven immunosuppression within renal tumors of obese mice. In our in vivo studies, we utilized a BALB/c mouse model of diet-induced obesity (DIO) and lean controls in combination with the Renca-Luc RCC cell line. Using flow cytometry and western blot, we respectively assessed leukocyte populations producing IL-1β and tumor energetics. Flow cytometry revealed that intra-tumoral IL-1β is produced primarily by tumor associated macrophages (TAMS). Immunoblotting demonstrated that increased IL-1β production is linked to altered mitochondrial function and ATP production. These early findings support the hypothesis that obesity driven IL-1β expression is mediated by tumor-associated macrophages and that mitochondrial dysfunction drives immune suppression. Understanding these molecular and immune-related mechanisms may pave the way for novel strategies to reduce immunosuppression in obese RCC patients, thus improving immunotherapeutic efficacy and overall clinical outcomes.
Citation Format: Henry Nnaemeka Ogbonna, Zachary Roberts, Haley Kvarnberg, Francesca Dempsey, Patrick N. Song, Anna G. Sorace, Lyse Norian. Investigating the role of host obesity in promoting immunotherapy resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3980.
Abstract 3993: A tunable safety switch for solid tumor CAR T-cell therapy
Authors: Misawa Kyohei , Taleb Meriem , Banerjee Srijita , Vista William-Ray , Chintala Navin K. , Adusumilli Prasad S. 
Published: March 2024

Abstract
On-target off-tumor toxicity, cytokine release syndrome (CRS), and immune effector cell-associated neurotoxicity syndrome (ICANS) are severe immune-related adverse events (irAEs) that are frequently associated with Chimeric Antigen Receptor (CAR) T-cell therapy. Current efforts to manage such therapy-related toxicities involve incorporation of an inducible suicide agent within CAR constructs, such as iCaspase-9 or herpes simplex virus type 1 thymidine kinase that can be selectively activated to produce toxic effects within CAR T cells and attenuate their activity. However, while activation of these agents helps to mitigate or overcome such unwarranted toxicities, the therapeutic benefit of CAR T cells anti-tumor activity is also compromised. Therefore, to continue maintenance of CAR T cells’ therapeutic function while minimizing irAEs, an ideal safety switch should 1) rapidly inhibit the activation and proliferation of CAR T cells exposed to the target antigen, 2) reversibly inhibit activity without inducing CAR T cell elimination and 3) be clinically translatable for safe application in patients. Our laboratory investigated one such safety switch to inhibit CAR T-cell activity while maintaining their therapeutic function. We showed that incorporating a mutant variant of c-KIT D816V (KITv) in the intracellular domain of mesothelin-targeting second-generation CAR T cells (M28z-KITv) improved efficacy in solid tumors with low antigen, or an immunosuppressive environment. Herein, we evaluate the use of Dasatinib, a clinically available multitarget (BCR, SRC, c-KIT) tyrosine kinase inhibitor (TKI), as a tunable safety switch to reversibly inhibit M28z-KITv CAR T-cell functional activity. In cohorts of mice established with lung adenocarcinoma, daily administration of Dasatinib starting on day 1 or day 3 after CAR T-cell administration stabilized tumor growth, which otherwise continued to regress in untreated mice, indicating inhibition of CAR T-cell functional activity. Upon discontinuation of Dasatinib, tumors regressed, indicating reversal of CAR T-cell functional activity. In an experiment conducted to investigate functional persistence of CAR T cells upon long-term exposure to Dasatinib (1 month), we noted uninhibited activity of CAR T cells to rechallenged tumors. Dasatinib, thus may act as a tunable safety switch to regulate M28z-KITv CAR T-cell activity without compromising its therapeutic function.
Citation Format: Kyohei Misawa, Meriem Taleb, Srijita Banerjee, William-Ray Vista, Navin K. Chintala, Prasad S. Adusumilli. A tunable safety switch for solid tumor CAR T-cell therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3993.
Abstract 4011: Locoregional GPC3 chimeric antigen receptor (CAR)-T cell therapy is associated with improved tumor control in hepatocellular carcinoma by enhancing CAR-T cell trafficking and functionality
Authors: Wang Jue , Tsang Kinching , Qiu Jiale , Feng Bo 
Published: March 2024

Abstract
Despite the rapid development of anti-cancer immunotherapy, the prognosis of hepatocellular carcinoma (HCC) patients is far from satisfactory. Glypican-3 (GPC3) CAR-T cell therapy has shown varied patient response. One of the potential reasons of low response rates may be due to the limited CAR-T cell infiltration. Therefore, locoregional GPC3 CAR-T therapy has been a promising option, with a hope of enhancing CAR-T cell tumor penetration. In this study, the therapeutic efficacy and underlying mechanisms of locoregional GPC3 CAR-T cell delivery were explored using HCC mouse xenografts. Orthotopic NOD-scid IL2Rgnull (NSG) HCC models were established by tumor fragment implantation into the liver. CAR-T cell injections were performed via the tail vein and portal vein to simulate systemic and locoregional administrations, respectively. Compared to the systemic treatment, locoregional therapy could better control the tumor growth, and was associated with improved liver function. In addition, the locoregional therapy group demonstrated a higher percentage of tumor-infiltrating CAR-T cells which showed an increased expression level of the cytotoxicity marker GZMB and a reduced level of the exhaustion marker LAG3. Moreover, significantly higher IFN-gamma level was found in the blood of the locoregional therapy group, indicating a better CAR-T cell functionality. In conclusion, we have demonstrated that locoregional administration of CAR-T cells is associated with increased CAR-T cell infiltration and better therapeutic efficacy. Additionally, CAR-T cells being injected locoregionally are correlated with enhanced functionality and reduced exhaustion phenotype. These findings highlight the potential of locoregional GPC3 CAR-T therapy as a promising treatment strategy for HCC patients.
Citation Format: Jue Wang, Kinching Tsang, Jiale Qiu, Bo Feng. Locoregional GPC3 chimeric antigen receptor (CAR)-T cell therapy is associated with improved tumor control in hepatocellular carcinoma by enhancing CAR-T cell trafficking and functionality [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4011.
Abstract 4019: Development of mRNA chimeric antigen receptor T cells targeting MET in aggressive B-cell lymphomas
Authors: Chen Po-Han , Raghunandan Rianna , Muschen Markus , Katz Samuel G. 
Published: March 2024

Abstract
Multiple versions of CAR T cells targeting the cell surface protein CD19 are approved by the FDA to treat refractory B-cell malignancies. However, durable remissions range from 60% in B-cell leukemias to 40% in B-cell lymphomas. Major reasons for resistance to CD19-CAR treatment relate to heterogeneous or loss of CD19 expression. In addition, CD19-CAR leads to B-cell depletion which increases the risk for infection. These limiting factors necessitate research into alternative targets for CAR therapy against B-cell lymphomas.Using a large data set from clinical trials, we found that approximately 30-70% of diffuse large B-cell lymphomas (DLBCL) express MET. We hypothesize that these MET-positive B-cell lymphomas can potentially be targeted with chimeric antigen receptor (CAR) T-cells against MET receptor. We constructed a second-generation anti-MET-CAR by fusing the scFv fragment of an anti-MET monoclonal antibody with the human CD28 hinge/transmembrane/cytoplasmic domain and CD3ζ cytoplasmic domain. Stable MET-CAR Jurkat cells showed increased CD69 expression upon stimulation by MET-positive lymphoma cell lines such as Karpas-422 and OCI-LY3. Using primary human T cells, we further demonstrated that the mRNA MET-CAR T-cells mediated cytotoxicity against DLBCL cell lines. Of note, while CD19-CAR T-cells showed only low level of cytotoxicity against the CD19-/MET+ OCI-LY3 cell line, MET-CAR T cell was able to mediate substantial tumor cell lysis.In summary, the preliminary data demonstrate that MET-CAR is capable of mediating cytotoxicity against MET-positive DLBCL. Some cell lines such as OCI-LY3 are negative for CD19 but positive for MET expression, and MET-CAR is capable of mediating cell lysis while CD19-CAR is ineffective. These results suggest that some large B-cell lymphomas negative for CD19, either intrinsic or secondary to loss of CD19 as a result of resistance mechanism, may show MET expression and will likely benefit from MET-targeted immunotherapy.
Citation Format: Po-Han Chen, Rianna Raghunandan, Markus Muschen, Samuel G. Katz. Development of mRNA chimeric antigen receptor T cells targeting MET in aggressive B-cell lymphomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4019.
Abstract 4021: The development of CAR T cell therapeutics targeting tumor specific CD146
Authors: Uzuner Erez , Mole Holly , Wong Chun W. , Carro Macarena L. Fernandez , Leshem Rotem , Sefton Kieran , Tovey Helen , Picken Andrew , Blot-Chabaud Marcel , Hurlstone Adam F. 
Published: March 2024

Abstract
Chimeric antigen receptor (CAR) T cells represent a promising class of "living drugs" for cancer treatment. These primary T cells are genetically engineered to express a synthetic antigen receptor, incorporating various domains to enhance their effector functions. While CAR T cells have shown success against liquid cancers, their application to solid cancers is hindered by significant "on-target/off-tumor" toxicities due to the absence of specific target proteins. In this study, we aim to enhance the tumor specificity of CAR T cells by targeting a tumor-specific version of CD146. CD146 is a glycoprotein widely expressed in several solid tumors, particularly melanoma and ovarian cancer. However, it is also expressed on benign cells, such as endothelial cells, pericytes, and smooth muscle cells. Nevertheless, a CD146 isoform exists that is enriched in cancer cells.
We assessed CAR activity using flow cytometry to measure surface CD69 expression (an early activation marker) on CAR-expressing Jurkat cells co-cultured with various CD146-positive and CD146-negative human melanoma and ovarian cancer cell lines. The killing ability of primary CAR-T cells was evaluated by measuring the relative luciferase activity of target cells, and their effector functions were further analyzed by ELISA for the secretion of IFN-g and TNF-a.
Through multiple rounds of protein engineering, we have developed a CAR construct capable of reprogramming T cells to respond to a tumour-enriched CD146 isoform. Our CAR demonstrated antigen-dependent activation of Jurkat cells when co-cultured with CD146-positive human melanoma and ovarian cancer cell lines, comparable to a CAR targeting pan-CD146. Moreover, primary CAR T cells exhibited proportional killing activity and other effector functions.
We have successfully engineered a CAR with specificity for a tumour-enriched isoform of CD146. Our future work will involve rigorously evaluating the tumor selectivity of our CAR, as well as assessing the ability of primary CAR T cells expressing this CAR to control tumor growth in vivo.
Citation Format: Erez Uzuner, Holly Mole, Chun W. Wong, Macarena L. Fernandez Carro, Rotem Leshem, Kieran Sefton, Helen Tovey, Andrew Picken, Marcel Blot-Chabaud, Adam F. Hurlstone. The development of CAR T cell therapeutics targeting tumor specific CD146 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4021.
Abstract 4026: The combination of DLL4/VEGF-a blockade and immunomodulation can eliminate MHC class I negative tumors in mice
Authors: Albu Diana I. , Duffy Rachael , Ulumben Amy Daniel , Kong Jason , Zolotarevsky Jessica , Brundin Melissa , Su Mei , Jadhav Ruturaj , Sachsenmeier Kris F. , Gong Bing , Schuetz Thomas J. , Visintin Alberto 
Published: March 2024

Abstract
CTX-009 is a bispecific antibody targeting VEGF-A and DLL4 which is undergoing clinical investigation in patients with multiple tumor types, including biliary tract and colon cancers. In biliary tract cancers, checkpoint inhibitor therapy has been shown to improve outcomes when combined with chemotherapy. In an effort to increase the breadth and duration of response of CTX-009, we set out to investigate the combined anti-tumor efficacy of this bispecific antibody and immunotherapy in preclinical models. Here we report the evaluation of the combination of the mouse surrogates of CTX-009 and CTX-471, an agonistic anti-mouse CD137 antibody, or monoclonal antibodies that disrupt the PD-1/PD-L1 signaling axis. Coupling VEGF-A/DLL4 targeting with either CD137 agonism or PD-1/PD-L1 blockade markedly increased the anti-tumor efficacy of the individual treatments alone in multiple syngeneic mouse tumor models. Tumor growth inhibition was accompanied by pharmacodynamic evidence consistent with enhancement of anti-tumor immunity. Notably, the combination of CTX-009 and CTX-471 retained potent anti-tumor activity even in a tumor line (MC38) which was made MHC I deficient through the deletion of the beta 2 microglobulin gene. This system may model the clinically relevant unmet need characterized by tumor escape through the loss of antigen presentation machinery such as HLA LOH. Interestingly, the model cell lines CT26 and MC38 failed to thrive in the B2M-deficient setting and depletion of NK cells markedly increased their ability to grow. This implies that NK cells might be involved in controlling tumor growth in this setting, and that the combined action of CTX-471 and CTX-009 in the tumor stroma enhances NK cell activity. The findings presented here suggest that CTX-009 may provide enhanced clinical benefit when combined with immunomodulatory agents, such as agonistic anti-CD137 antibodies or PD-1/PD-L1 blockers in tumors where immune checkpoint inhibitors have failed.
Citation Format: Diana I. Albu, Rachael Duffy, Amy Daniel Ulumben, Jason Kong, Jessica Zolotarevsky, Melissa Brundin, Mei Su, Ruturaj Jadhav, Kris F. Sachsenmeier, Bing Gong, Thomas J. Schuetz, Alberto Visintin. The combination of DLL4/VEGF-a blockade and immunomodulation can eliminate MHC class I negative tumors in mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4026.
Abstract 4052: Neutrophil recruitment and activation promotes cutaneous adverse effects with T cell immunotherapies
Authors: Hirschhorn Daniel , Kraehenbuehl Lukas , Budhu Sadna , Navarro Valeria Estrada , Mangarin Levi Mark B , Marouf Yacine , Ricca Jacob , Gasmi Billel , De Henau Olivier , Li Yanyun , Cortez Czrina , Linda Hamadene , Schulze Isabell , Liu Cailian , Panageas Katherine , Lacuoture Mario , Rizzuto Gabrielle A. , Egeblad Mikala , Wolchok Jedd D. , Merghoub Taha Merghoub 
Published: March 2024

Abstract
Immune-based therapies that induce tumor regression are often accompanied by immune-related adverse events (irAEs) which can occasionally present with severe and lethal symptoms. Currently, there are no well-defined preventative approaches to uncouple anti-tumor immunity from irAEs. Currently approved immunotherapies include agents that activate T cell responses, such as antibodies blocking immune checkpoints and infusion of tumor-derived, T cell receptor-transgenic or chimeric antigen receptor-modified T cells. While the beneficial and toxic effects of T cell-based therapies in the clinic are being extensively explored, the precise mechanisms underlying their activity remain the subject of investigation. In this study, we treated preclinical models of established melanomas with tumor-specific adoptive CD4+ T cell transfer in combination with T cell co-stimulation via OX40 agonism or CTLA-4 blockade. We found that, despite adequate T cell stimulation, acute local inflammation plays an important role in tumor elimination and the manifestation of irAEs. While stimulated T cells are necessary for initiating a therapeutic response, activation of endogenous neutrophils constitutes an important and necessary effector mechanism for both tumor destruction and the development of irAEs. Extensive neutrophil extracellular traps (NETs) were associated with irAEs. Furthermore, melanoma patients treated with immune checkpoint blockade with skin rashes equivalent to irAEs found in mice showed increased survival and NETs in biopsies from both rashes and tumors. Our results bring forward a novel paradigm where T cells prime an anti-tumor immune response that is followed by an inflammatory effector mechanism provided by the innate immune system, resulting in both curative and undesirable side effects in mice and patients.
Citation Format: Daniel Hirschhorn, Lukas Kraehenbuehl, Sadna Budhu, Valeria Estrada Navarro, Levi Mark B Mangarin, Yacine Marouf, Jacob Ricca, Billel Gasmi, Olivier De Henau, Yanyun Li, Czrina Cortez, Hamadene Linda, Isabell Schulze, Cailian Liu, Katherine Panageas, Mario Lacuoture, Gabrielle A. Rizzuto, Mikala Egeblad, Jedd D. Wolchok, Taha Merghoub Merghoub. Neutrophil recruitment and activation promotes cutaneous adverse effects with T cell immunotherapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4052.