Cell-mediated Immunotherapy Research Articles

Integrating clinical and genomic landscape analysis of perineural invasion identify ACTA1 as an oncogene for oral squamous cell carcinoma.

Perineural invasion (PNI) has been shown to be a key pathological feature of several types of cancer, including oral squamous epithelial carcinoma (OSCC). However, the overall clinical and genomic landscape of PNI+ OSCC are still unclear, and the molecular mechanism of PNI remains to be further investigated. 279 OSCC samples were extracted from the TCGA database and grouped according to PNI. The clinicopathological information, prognostic and survival analyses were performed. The Cibersort algorithm and ESTIMATE algorithm was used to estimate the impacts on proportion of immune cells, immune score and stromal score by PNI. Immunotherapy prediction analysis was also performed. 167 differentially expressed genes were screened for functional enrichment analysis. Actin α1 (ACTA1) protein, which was significantly upregulated in the PNI+ group, was selected for validation in our OSCC patient's cohort (n = 70). We next analyzed the ratio and absolute number of key immunocytes in peripheral blood of OSCC patients according to Actin α1 expression by flow cytometry. PNI was more likely to occur in patients with advanced tumors and worse prognosis. Immunomodulation analyses showed that T cells follicular helper and cells were significantly lower, but M2 macrophages and total stromal score was significantly higher in PNI+ OSCC. Immunotherapy prediction analyses showed that PNI+ OSCC may be more sensitive to CTLA4 inhibitor treatment. 167 differentially expressed genes were identified and enriched in muscle structure and cell movement-related pathway. Among them, Actin α1 (ACTA1) was significantly upregulated in PNI+ advanced OSCC with worse clinical outcome whose had relatively low ratio of CD3+CD8+ circulating cytotoxic T cells. PNI+ OSCC patients with upregulated of Actin α1 could benefit from cytotoxic T cell-mediated immunotherapy.

Engineering of a Multi-Modular DNA Nanodevice for Spatioselective Imaging and Evaluation of NK Cell-Mediated Cancer Immunotherapy.

Granzyme A (GzmA) secreted by natural killer (NK) cells has garnered considerable interest as a biomarker to evaluate the efficacy of cancer immunotherapy. However, current methodologies to selectively monitor the spatial distribution of GzmA in cancer cells during NK cell-targeted therapy are extremely challenging, primarily due to the existence of diverse cell populations, the low levels of GzmA expression, and the limited availability of GzmA probes. Herein we develop a multi-modular, structurally-ordered DNA nanodevice for evaluating NK cell-mediated cancer immunotherapy (MODERN), that permits spatioselective imaging of GzmA in cancer cells through GzmA-induced apurinic/apyrimidinic endonuclease 1 (APE1) inactivation. The MODERN incorporates multiple functional modules, including an APE1-gated recognition module, a photo-activated amplification module, an aptamer-mediated tumor-target module, and a polycatenane DNA module, enabling improved sensitivity and specificity towards intracellular GzmA. The MODERN was activated (on) in cancer cells due to the overexpression of APE1, whereas it remained silent (off) in the NK-treated cancer cells owing to the GzmA-induced APE1 inactivation. Furthermore, we demonstrated that GzmA-induced APE1 inactivation blocks the cellular repair of target cells, resulting in efficient cell death. This MODERN that relies on the specific inactivation of APE1 by GzmA should be beneficial for evaluating the efficacy of cancer immunotherapy.

Dual Adjuvant-Loaded Peptide Antigen Self-Assembly Potentiates Dendritic Cell-Mediated Tumor Immunotherapy.

Clinical translation of current cancer vaccine research has been hampered by limited antitumor immune responses due to inefficient antigen delivery and presentation, suboptimal DC and T cell activation. Biomaterial-based nanovaccine offers targeted antigen delivery, protection from degradation in vivo, and prolonged tumor therapeutic efficacy. This study introduces a lipid-coated deoxycholic acid-survivin nanoassembly (DA-L-DSA). Survivin, overexpressed in several cancer cells and involved in cancer cell growth and immune evasion, is selected as a tumor-associated antigen. An major histocompatibility complex class I binding epitope of survivin is engineered into the nanoassembly. R848, TLR 7/8 agonist, and SD-208, TGF-beta receptor1 kinase inhibitor, are coencapsulated into the nanoassembly as potent adjuvants to boost DC maturation and enhance antigen presentation. The DA-L-DSA effectively stimulates the maturation of dendritic cells, migrates into lymph nodes, and enhances T-cell activation and Th1 response. A substantial influx of cytotoxic T lymphocytes into primary tumors is observed in a murine melanoma model and demonstrates anti-metastatic effects in a spontaneous breast cancer metastasis model. Furthermore, DA-L-DSA exhibits a remarkable synergistic effect in the combination therapy with immune checkpoint inhibitors alleviating immunosuppressive tumor microenvironment. Taken together, these findings suggest DA-L-DSA as a promising immuno-therapeutic platform that could be applicable to diverse intractable cancers.

Complex immune microenvironment of chordoma: a road map for future treatment

BackgroundChordoma, a rare bone tumor, presents limited treatment options and patients typically exhibit poor survival outcomes. While immunotherapy has shown promising results in treating various tumors, research on the immune...

Death receptors 4/5 mediate tumour sensitivity to natural killer cell-mediated cytotoxicity in mismatch repair deficient colorectal cancer.

Identifying the target of natural killer (NK) cells in colorectal cancer (CRC) is critical for optimising the clinical use of NK cell-mediated immunotherapy. Mismatch repair deficiency (dMMR) is associated with high immune cell infiltration and MHC Class I defects. Whether dMMR CRC responses to NK cell therapy remains unclear. MLH1, DR4, and DR5 knockout cell lines were established using CRISPR-Cas9 system. NK92-MI or NK cell isolated from BABL/C mice were used as effector cells against tumour cells. Inflammatory cytokines secretion by CRC cells was assessed via cytokine analysis. NK-cell-deficient/proficient animal models were used to validate the NK cell sensitivity. We observed that dMMR CRC cells were more sensitive to NK cell-mediated cytotoxicity than were mismatch-repair-proficient (pMMR) CRC cells. In dMMR CRC, Death receptor (DR)4/5 was upregulated and mediated sensitivity to NK cell-mediated cytotoxicity. DR4/5-mediated secretion of interleukin -12 sustained NK cell viability in dMMR CRC. NK cell depletion induced dMMR CRC tumour growth, and NK cell transfer inhibited lung metastasis of dMMR CRC with DR4/5 expression in vivo. TP53 upregulated DR4/DR5 expression in dMMR CRC. dMMR associated with increased sensitivity to NK cell-mediated cytotoxicity in CRC. DR4/DR5 sensitise dMMR CRC to NK cell-mediated cytotoxicity.

Correction to “Mannosylated STING Agonist Drugamers for Dendritic Cell-Mediated Cancer Immunotherapy”

Correction to “Mannosylated STING Agonist Drugamers for Dendritic Cell-Mediated Cancer Immunotherapy”

THEMIS2 Impairs Antitumor Activity of NK Cells by Suppressing Activating NK Receptor Signaling.

NK cells are cytotoxic innate lymphocytes that play a critical role in antitumor immunity. NK cells recognize target cells by using a repertoire of activating NK receptors and exert the effector functions. Although the magnitude of activation signals through activating NK receptors controls NK cell function, it has not been fully understood how these activating signals are modulated in NK cells. In this study, we found that a scaffold protein, THEMIS2, inhibits activating NK receptor signaling. Overexpression of THEMIS2 attenuated the effector function of human NK cells, whereas knockdown of THEMIS2 enhanced it. Mechanistically, THEMIS2 binds to GRB2 and phosphorylated SHP-1 and SHP-2 at the proximity of activating NK receptors DNAM-1 and NKG2D. Knockdown of THEMIS2 in primary human NK cells promoted the effector functions. Furthermore, Themis2-deficient mice showed low metastatic burden in an NK cell-dependent manner. These findings demonstrate that THEMIS2 has an inhibitory role in the antitumor activity of NK cells, suggesting that THEMIS2 might be a potential therapeutic target for NK cell-mediated cancer immunotherapy.

Abstract 1372: BTN1A1 regulates T cell-mediated cancer immunotherapy by interacting with Galectin-9, PD-1, and TIM3

Abstract Butyrophilin 1A1 (BTN1A1) is a novel immune checkpoint protein belonging to the butyrophilin family and is expressed on immune cells such as macrophages, B cells, or activated CD8 T cells and in human tumors. Our results indicate that BTN1A1 and PD-L1 expression are mutually exclusive in various human solid tumors. Furthermore, it was observed that BTN1A1 had a significantly higher detection level than PD-L1 in cancer patient samples. We have reported that BTN1A1 plays an immunomodulatory role in T cell activation and proliferation. BTN1A1 inhibited the proliferation of T cells that are activated by anti-CD3 and anti-CD28 antibodies in vitro. Overexpression of BTN1A1 in PC3 cells also inhibits T cell-mediated killing of cancer cells. BTN1A1 is a bona fide immune checkpoint inhibitor and has anti-tumor activity in a human immune setting. BTN1A1 represents a novel cancer immunotherapy target that goes beyond the low expression levels of PD-1/PD-L1 in tumors. BNT1A1 is an immune checkpoint and cell membrane protein that, together with its binding partners, serves as a starting point for signaling pathways. The BNT1A1 complex, which has various abilities by combining with a specific partner, plays a vital role as an immune checkpoint. In this study, we identified binding partners of BTN1A that regulate immune activity in a mutually interaction relationship with BTN1A1 in various ways. We identified binding partners for the extracellular domain of human BTN1A1 using cell microarrays from Retrogenix (Whaley Bridge, UK). Through this screening approach, we found that BTN1A1 binds to galectin-1 (Gal1), galectin-9 (Gal9), and neuropilin 2 (NRP2). These three putative binding partners could specifically bind to wild-type BTN1A1 but not to this protein's unglycosylated (2NQ) form. Of these three targets, immunoprecipitation and Biacore binding assays revealed that Gal9 exhibited the greatest affinity for human BTN1A1. Since Gal9 is a known PD-1 and TIM3 binding protein, we predicted the potential formation of a BTN1A1/Gal9/PD-1 or BTN1A1/Gal9/TIM3 complex. Indeed, it reveals that immunoprecipitation and confocal microscopy assays performed using cells expressing Myc-tagged versions of these four proteins demonstrated the formation of BTN1A1/Gal9, PD-1/Gal9, TIM3/Gal9, BTN1A1/Gal9/TIM3, and BTN1A1/Gal9/PD-1 complexes. In T cell activation assay using these complexes, when present BTN1A1 alongside the complex inhibits activated T cells. As high Gal9 expression levels are correlated with poor prognosis in multiple cancers, our results highlight this BTN1A1-Gal9-PD-1 or BTN1A1-Gal9-TIM3 axis as a novel therapeutic target for immunotherapeutic drug development. Citation Format: Seung Hoon Lee, Young-Seung Kim, Chunai Wu, Andrew H Park, Stephen S. Yoo. BTN1A1 regulates T cell-mediated cancer immunotherapy by interacting with Galectin-9, PD-1, and TIM3 [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 1372.

Abstract 111: Establishing orthotopic renal cell carcinoma xenograft in PBMC-humanized immunodeficient NSG-MHC I/II double knock-out mice

Abstract Clear cell renal cell carcinoma (ccRCC), the predominant histological subtype of RCC, is highly correlated with immune cells, an association that is linked to a worse prognosis. Our study aimed to establish an orthotopic ccRCC mouse model reconstituted with human peripheral blood mononuclear cells (PBMCs) and implanted with human ccRCC SKRC-59 cells under the kidney capsule in immunodeficient NSG-MHC I/II double knock-out (DKO) mice. The study was conducted using two experimental designs to optimize humanization and tumor formation. In the first experimental design, the mice were engrafted with SKRC-59 cells under the left kidney capsule 24 hours post-irradiation on study day 0. The PBMCs were then injected intravenously on study day 9. The second experimental design involved irradiating mice on study day -1, followed by engraftment with PBMCs either perfectly (6/6) or partially (3/6) matched human leukocyte antigens (HLA) with the tumors. Subsequently, SKRC-59 cells were placed under the kidney capsule on study day 0. Daily post-operative observations were conducted for six days following surgery to ensure the well-being of the mice. Tumor burden was assessed twice weekly using an in vivo imaging system, along with monitoring body weights and clinical signs. The humanization rates were evaluated 7, 14, and 21 days post-PBMC engraftment, as well as at the end of the study, using peripheral blood. Approximately 5 to 6 weeks post-tumor implantation, the mice were euthanized, and both left and right kidneys were collected and weighed for further analysis. The humanization rates were significantly higher when the PBMCs were engrafted on the same day as irradiation compared to 10 days post-irradiation. The PBMC humanization, and HLA-type PBMC donors did not affect tumor burden. Additionally, we found that distant metastasis in the lungs developed in several mice. Using flow cytometry and immunohistochemistry (IHC) to analyze tumor infiltrating leukocytes (TILs), a predominant number of CD3+ T cells were found in human CD45+ TILs, indicating that this model could be useful for evaluating T cell-mediated immunotherapies. Moreover, lympho-myeloid aggression (LMA) was observed in this peripheral blood leukocytes (PBL) mouse model, showing early stage tertiary lymphoid structures (TLS), which potentially provides a powerful tool to recapitulate TLS formation and study associated mechanisms and therapies. Our study demonstrated the growth of ccRCC SKRC-59 tumors under the renal capsule and observed TILs and metastatic patterns in PBMC humanized DKO mice. This PBMC-humanized orthotopic ccRCC xenograft model can recapitulate tumor microenvironment (TME), and be potentially used to assess the safety and efficacy of various immunotherapeutics. Citation Format: Wonyoung Kang, Yufei Wang, Yasmin N. Laimon, Oanh Pham, Ben Matran, Lauren Bottoms, Sheng Khang, Hsien-Chi Yuan, Nithyassree Murugan, Aseman B. Sheshdeh, Li-chin Yao, Jiwon Yang, Mingshan Cheng, Sabina Signoretti, Wayne A. Marasco, James G. Keck. Establishing orthotopic renal cell carcinoma xenograft in PBMC-humanized immunodeficient NSG-MHC I/II double knock-out 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 111.

Abstract 17: Metabolic screening of T cells guides the enrichment of stem cell memory phenotype

Abstract The efficacy of T cell-mediated immunotherapy is improved by the proliferation of T cells with a stem cell memory phenotype (Tscm). These cells are capable of long-term persistence, self-renewal, multipotency, and robust engagement with cancer cells. This study focuses on refining T cell activation protocols to bolster the presence of Tscm within the therapeutic arsenal against cancer. Through a series of cell health and metabolic assays, we traced the activation-induced metabolic reprogramming that results from Tscm enrichment. Ex vivo activation was characterized by a rapid 2.5-3 fold increase in ATP production and a 2 fold shift in intracellular reducing potential, paralleling the metabolic demands of Tscm in the cancer microenvironment. Progression of activation intensified the metabolic flux through catabolic and anabolic pathways, with significant fluctuations in metabolites such as glucose, lactate, glutamine, glutamate, branched chain amino acids, and pyruvate. These metabolic alterations were accompanied by a 2 fold increase in the prevalence of Tscm cells, and demonstrated a dependency on media composition. Our findings reveal that metabolic profiling during T cell activation provides early and actionable insights into the enrichment of Tscm, and may serve as a strategic guideline for the enhancement of cancer immunotherapies. Citation Format: Anthony Lauer, Natasha Karassina, Kayla Sylvester, Jolanta Vidugiriene. Metabolic screening of T cells guides the enrichment of stem cell memory phenotype [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 17.

Aptamer-Based Nongenetic Reprogramming of CARs Enables Flexible Modulation of T Cell-Mediated Tumor Immunotherapy.

Innovating the design of chimeric antigen receptors (CARs) beyond conventional structures would be necessary to address the challenges of efficacy, safety, and applicability in T cell-based cancer therapy, whereas excessive genetic modification might complicate CAR design and manufacturing, and increase gene editing risks. In this work, we used aptamers as the antigen-recognition unit to develop a nongenetic CAR engineering strategy for programming the antitumor activity and specificity of CAR T cells. Our results demonstrated that aptamer-functionalized CAR (Apt-CAR) T cells could be directly activated by recognizing target antigens on cancer cells, and then impart a cytotoxic effect for cancer elimination in vitro and in vivo. The designable antigen recognition capability of Apt-CAR T cells allows for easy modulation of their efficacy and specificity. Additionally, multiple features, e.g., tunable antigen-binding avidity and the tumor microenvironment responsiveness, could be readily integrated into Apt-CAR design without T cell re-engineering, offering a new paradigm for developing adaptable immunotherapeutics.

Mannosylated STING Agonist Drugamers for Dendritic Cell-Mediated Cancer Immunotherapy.

The Stimulator of Interferon Genes (STING) pathway is a promising target for cancer immunotherapy. Despite recent advances, therapies targeting the STING pathway are often limited by routes of administration, suboptimal STING activation, or off-target toxicity. Here, we report a dendritic cell (DC)-targeted polymeric prodrug platform (polySTING) that is designed to optimize intracellular delivery of a diamidobenzimidazole (diABZI) small-molecule STING agonist while minimizing off-target toxicity after parenteral administration. PolySTING incorporates mannose targeting ligands as a comonomer, which facilitates its uptake in CD206+/mannose receptor+ professional antigen-presenting cells (APCs) in the tumor microenvironment (TME). The STING agonist is conjugated through a cathepsin B-cleavable valine-alanine (VA) linker for selective intracellular drug release after receptor-mediated endocytosis. When administered intravenously in tumor-bearing mice, polySTING selectively targeted CD206+/mannose receptor+ APCs in the TME, resulting in increased cross-presenting CD8+ DCs, infiltrating CD8+ T cells in the TME as well as maturation across multiple DC subtypes in the tumor-draining lymph node (TDLN). Systemic administration of polySTING slowed tumor growth in a B16-F10 murine melanoma model as well as a 4T1 murine breast cancer model with an acceptable safety profile. Thus, we demonstrate that polySTING delivers STING agonists to professional APCs after systemic administration, generating efficacious DC-driven antitumor immunity with minimal side effects. This new polymeric prodrug platform may offer new opportunities for combining efficient targeted STING agonist delivery with other selective tumor therapeutic strategies.

Clinical and Immunological Significance of ANKRD52 in Pan-Cancer.

Ankyrin repeat domain 52 (ANKRD52) is a regulatory component of the protein phosphatase 6 (PP6) holoenzyme. Evidence has emerged to suggest involvement of ANKRD52 in tumor metastases and cancer cell escape from T cell-mediated elimination and immunotherapy but there has been no research across different cancer types. The current study explored the biological functions of ANKRD52 by combining data from many databases. The aim was to expose new diagnostic or treatment biomarkers for malignant tumors. The roles of ANKRD52 with respect to immunotherapy in 33 human cancer types were analyzed by combining data from The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx), Cancer Cell Line Encyclopedia (CCLE), UCSC Xena, the Tumor Immune Estimation Resource (TIMER), TISIDB and Cellminer. Bioinformatics methods were used to analyze the association between ANKRD52 expression and prognosis, immunological indicators (immune cell infiltration, ESTIMATE scores and tumor microenvironment (TME) signatures), tumor mutational burden (TMB), microsatellite instability (MSI) and drug sensitivity. ANKRD52 expression was generally higher in 24 tumor tissues than in normal tissues and was associated with poor prognosis, especially in kidney chromophobe (KICH). Lower expression was observed in advanced cancer. ANKRD52 expression was strongly linked to major immunological indicators, such as immune cell infiltration, ESTIMATE scores, TME signatures, as well as expression of immune and tumor-related genes. Expression was also associated with indicators of immunotherapy efficacy and outcome, such as TMB in 7 cancer types and MSI in 12. In addition, ANKRD52 expression was linked to sensitivity to a number of anticancer drugs. ANKRD52 had a distinct immune function in breast invasive carcinoma (BRCA) that correlated negatively with most immune indicators. Expression was enriched in proliferation-, differentiation- and metabolism-related pathways and linked to other immune cells and TME signatures. A nomogram to predict 3- or 5-year overall survival (OS) of patients with BRCA was constructed. ANKRD52 may have utility as an oncological and immunological biomarker. New insights into oncogenesis are presented and the development of ANKRD52-targeting to increase the therapeutic efficacy of immunotherapy combined with chemotherapy explored.

Environment-responsive dendrobium polysaccharide hydrogel embedding manganese microsphere as a post-operative adjuvant to boost cascaded immune cycle against melanoma.

Rationale: Surgical resection is a primary treatment for solid tumors, but high rates of tumor recurrence and metastasis post-surgery present significant challenges. Manganese (Mn2+), known to enhance dendritic cell-mediated cancer immunotherapy by activating the cGAS-STING pathway, has potential in post-operative cancer management. However, achieving prolonged and localized delivery of Mn2+ to stimulate immune responses without systemic toxicity remains a challenge. Methods: We developed a post-operative microenvironment-responsive dendrobium polysaccharide hydrogel embedded with Mn2+-pectin microspheres (MnP@DOP-Gel). This hydrogel system releases Mn2+-pectin microspheres (MnP) in response to ROS, and MnP shows a dual effect in vitro: promoting immunogenic cell death and activating immune cells (dendritic cells and macrophages). The efficacy of MnP@DOP-Gel as a post-surgical treatment and its potential for immune activation were assessed in both subcutaneous and metastatic melanoma models in mice, exploring its synergistic effect with anti-PD1 antibody. Result: MnP@DOP-Gel exhibited ROS-responsive release of MnP, which could exert dual effects by inducing immunogenic cell death of tumor cells and activating dendritic cells and macrophages to initiate a cascade of anti-tumor immune responses. In vivo experiments showed that the implanted MnP@DOP-Gel significantly inhibited residual tumor growth and metastasis. Moreover, the combination of MnP@DOP-Gel and anti-PD1 antibody displayed superior therapeutic potency in preventing either metastasis or abscopal brain tumor growth. Conclusions: MnP@DOP-Gel represents a promising drug-free strategy for cancer post-operative management. Utilizing this Mn2+-embedding and ROS-responsive delivery system, it regulates surgery-induced immune responses and promotes sustained anti-tumor responses, potentially increasing the effectiveness of surgical cancer treatments.

A natural killer T cell nanoagonist-initiated immune cascade for hepatocellular carcinoma synergistic immunotherapy.

Natural killer T (NKT) cell-mediated immunotherapy shows great promise in hepatocellular carcinoma featuring an inherent immunosuppressive microenvironment. However, targeted delivery of NKT cell agonists remains challenging. Here, we developed a hyaluronic acid (HA) modified metal organic framework (zeolitic imidazolate framework-8, ZIF-8) to encapsulate α-galactosylceramide (α-Galcer), a classic NKT cell agonist, and doxorubicin (DOX) for eliminating liver cancer, denoted as α-Galcer/DOX@ZIF-8@HA. In the tumor microenvironment (TME), these pH-responsive nano-frameworks can gradually collapse to release α-Galcer for activating NKT cells and further boosting other immune cells in order to initiate an antitumor immune cascade. Along with DOX, the released α-Galcer enabled efficient NKT cell activation in TME for synergistic immunotherapy and tumor elimination, leading to evident tumor suppression and prolonged animal survival in both subcutaneous and orthotopic liver tumor models. Manipulating NKT cell agonists into functional nano-frameworks in TME may be matched with other advanced managements applied in a wider range of cancer therapies.

Surface Engineering of Natural Killer Cells with CD44-targeting Ligands for Augmented Cancer Immunotherapy.

Adoptive immunotherapy utilizing natural killer (NK) cells has demonstrated remarkable efficacy in treating hematologic malignancies. However, its clinical intervention for solid tumors is hindered by the limited expression of tumor-specific antigens. Herein, lipid-PEG conjugated hyaluronic acid (HA) materials (HA-PEG-Lipid) for the simple ex-vivo surface coating of NK cells is developed for 1) lipid-mediated cellular membrane anchoring via hydrophobic interaction and thereby 2) sufficient presentation of the CD44 ligand (i.e., HA) onto NK cells for cancer targeting, without the need for genetic manipulation. Membrane-engineered NK cells can selectively recognize CD44-overexpressing cancer cells through HA-CD44 affinity and subsequently induce in situ activation of NK cells for cancer elimination. Therefore, the surface-engineered NK cells using HA-PEG-Lipid (HANK cells) establish an immune synapse with CD44-overexpressing MIA PaCa-2 pancreatic cancer cells, triggering the "recognition-activation" mechanism, and ultimately eliminating cancer cells. Moreover, in mouse xenograft tumor models, administrated HANK cells demonstrate significant infiltration into solid tumors, resulting in tumor apoptosis/necrosis and effective suppression of tumor progression and metastasis, as compared to NK cells and gemcitabine. Taken together, the HA-PEG-Lipid biomaterials expedite the treatment of solid tumors by facilitating a sequential recognition-activation mechanism of surface-engineered HANK cells, suggesting a promising approach for NK cell-mediated immunotherapy.

Ezurpimtrostat, A Palmitoyl-Protein Thioesterase-1 Inhibitor, Combined with PD-1 Inhibition Provides CD8+ Lymphocyte Repopulation in Hepatocellular Carcinoma.

Palmitoyl-protein thioesterase-1 (PPT1) is a clinical stage druggable target for inhibiting autophagy in cancer. We aimed to determine the cellular and molecular activity of targeting PPT1 using ezurpimtrostat, in combination with an anti-PD-1 antibody. In this study we used a transgenic immunocompetent mouse model of hepatocellular carcinoma. Herein, we revealed that inhibition of PPT1 using ezurpimtrostat decreased the liver tumor burden in a mouse model of hepatocellular carcinoma by inducing the penetration of lymphocytes into tumors when combined with anti-programmed death-1 (PD-1). Inhibition of PPT1 potentiates the effects of anti-PD-1 immunotherapy by increasing the expression of major histocompatibility complex (MHC)-I at the surface of liver cancer cells and modulates immunity through recolonization and activation of cytotoxic CD8+ lymphocytes. Ezurpimtrostat turns cold tumors into hot tumors and, thus, could improve T cell-mediated immunotherapies in liver cancer.

Functional Nucleic Acid-Based Immunomodulation for T Cell-Mediated Cancer Therapy.

T cell-mediated immunity plays a pivotal role in cancer immunotherapy. The anticancer actions of T cells are coordinated by a sequence of biological processes, including the capture and presentation of antigens by antigen-presenting cells (APCs), the activation of T cells by APCs, and the subsequent killing of cancer cells by activated T cells. However, cancer cells have various means to evade immune responses. Meanwhile, these vulnerabilities provide potential targets for cancer treatments. Functional nucleic acids (FNAs) make up a class of synthetic nucleic acids with specific biological functions. With their diverse functionality, good biocompatibility, and high programmability, FNAs have attracted widespread interest in cancer immunotherapy. This Review focuses on recent research progress in employing FNAs as molecular tools for T cell-mediated cancer immunotherapy, including corresponding challenges and prospects.

Abstract A038: Targeting TCTP overcomes resistance to T cell-mediated immunotherapy by reversing the multi-malignant phenotypes of immune-refractory tumor cells

Abstract Cancer immunotherapy, particularly T cell-mediated therapy such as immune checkpoint blockade (ICB) and adoptive T cell transfer (ACT), has shifted the paradigm for cancer treatment. However, the emergence of immune-refractory tumor has limited its clinical success by disrupting one or more steps of the cancer immunity cycle. In addition, multi-malignant phenotypes of immune-refractory tumor cells are also one of the major causes result poor prognosis of patients. We need to identify novel predictive biomarker allowing for the selection of patients who will receive clinical benefit from immune-refractory tumors. Therefore, identifying the immune-resistance and multi-malignant factor, which not only can be targeted by clinically available medicines is very important. Here, we identified TCTP as a novel factor conferring multi-malignant phenotypes of immune-refractory tumor cells. We discovered a vital role of TCTP at the crossroads between multi-malignant tumor cells and the anti-cancer immunity system by demonstrating that TCTPhigh tumor cells enriched by immune selection pressure drive immune-refractory phenotypes. Importantly, the expression levels of TCTP within the tumors significantly associated with the clinical response of anti-PD-L1 therapy, which suggest TCTP as a prognostic marker in the case of clinical trials. Furthermore, targeting TCTP by clinical available drug overcomes the resistance to T cell-mediated therapy including ICB and ACT. Thus, our findings demonstrated that TCTP could be a both a valid target a prognostic marker providing a framework for patient selection to apply combined therapy of T cell-mediated therapy with TCTP-targeting drugs. Citation Format: Tae Woo Kim. Targeting TCTP overcomes resistance to T cell-mediated immunotherapy by reversing the multi-malignant phenotypes of immune-refractory tumor cells [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor Immunology and Immunotherapy; 2023 Oct 1-4; Toronto, Ontario, Canada. Philadelphia (PA): AACR; Cancer Immunol Res 2023;11(12 Suppl):Abstract nr A038.

Development of dendritic cell loaded MAGE-A2 long peptide; a potential target for tumor-specific T cell-mediated prostate cancer immunotherapy

BackgroundProstate cancer (PCa) is the second leading cause of cancer-related deaths among men worldwide. Immunotherapy is an emerging treatment modality for cancers that harnesses the immune system’s ability to eliminate tumor cells. In particular, dendritic cell (DC) vaccines, have demonstrated promise in eliciting a tumor-specific immune response. In this study, we investigated the potential of using DCs loaded with the MAGE-A2 long peptide to activate T cell cytotoxicity toward PCa cell lines.MethodsHere, we generated DCs from monocytes and thoroughly characterized their phenotypic and functional properties. Then, DCs were pulsed with MAGE-A2 long peptide (LP) as an antigen source, and monitored for their transition from immature to mature DCs by assessing the expression levels of several costimulatory and maturation molecules like CD14, HLA-DR, CD40, CD11c, CD80, CD83, CD86, and CCR7. Furthermore, the ability of MAGE-A2 -LP pulsed DCs to stimulate T cell proliferation in a mixed lymphocyte reaction (MLR) setting and induction of cytotoxic T cells (CTLs) in coculture with autologous T cells were examined. Finally, CTLs were evaluated for their capacity to produce interferon-gamma (IFN-γ) and kill PCa cell lines (PC3 and LNCaP).ResultsThe results demonstrated that the antigen-pulsed DCs exhibited a strong ability to stimulate the expansion of T cells. Moreover, the induced CTLs displayed substantial cytotoxicity against the target cells and exhibited increased IFN-γ production during activation compared to the controls.ConclusionsOverall, this innovative approach proved efficacious in targeting PCa cell lines, showcasing its potential as a foundation for the development and improved PCa cancer immunotherapy.