Tumor-specific Antigens Research Articles

Recent advances in mRNA-based cancer vaccines encoding immunostimulants and their delivery strategies

The high prevalence of drug resistance, relapse, and unfavorable response rate of conventional cancer therapies necessitate the development of more efficient treatment modalities. Immunotherapy represents a novel therapeutic approach to cancer treatment in which the immune system's potential is harnessed to recognize and eliminate tumor cells. mRNA cancer vaccines, as a burgeoning field of immunotherapy, have recently drawn particular attention, and among mRNAs encoding tumor-associated antigens, tumor-specific antigens, and immune stimulatory factors, the latter has been relatively less explored. These immunostimulatory mRNAs encode a range of proteins, including stimulatory ligands, receptors, enzymes, pro-inflammatory cytokines, and inhibitory binding proteins, which collectively augment the host immune system's ability against cancerous cells. In this review, we aimed to provide a comprehensive account of mRNA-based cancer vaccines encoding immune stimulants, encompassing their current status, mechanisms of action, delivery strategies employed, as well as recent advances in preclinical and clinical studies. The potential challenges, strategies and future perspectives have also been discussed.

Selective targeting of oncogenic hotspot mutations of the HER2 extracellular domain.

Oncogenic mutations in the extracellular domain (ECD) of cell-surface receptors could serve as tumor-specific antigens that are accessible to antibody therapeutics. Such mutations have been identified in receptor tyrosine kinases including HER2. However, it is challenging to selectively target a point mutant, while sparing the wild-type protein. Here we developed antibodies selective to HER2 S310F and S310Y, the two most common oncogenic mutations in the HER2 ECD, via combinatorial library screening and structure-guided design. Cryogenic-electron microscopy structures of the HER2 S310F homodimer and an antibody bound to HER2 S310F revealed that these antibodies recognize the mutations in a manner that mimics the dimerization arm of HER2 and thus inhibit HER2 dimerization. These antibodies as T cell engagers selectively killed a HER2 S310F-driven cancer cell line in vitro, and in vivo as a xenograft. These results validate HER2 ECD mutations as actionable therapeutic targets and offer promising candidates toward clinical development.

Vax-Innate: improving therapeutic cancer vaccines by modulating T cells and the tumour microenvironment.

T cells have a critical role in mediating antitumour immunity. The success of immune checkpoint inhibitors (ICIs) for cancer treatment highlights how enhancing endogenous T cell responses can mediate tumour regression. However, mortality remains high for many cancers, especially in the metastatic setting. Based on advances in thegenetic characterization of tumours and identification of tumour-specific antigens, individualized therapeutic cancer vaccines targeting mutated tumour antigens (neoantigens) are being developed to generate tumour-specific T cells for improved therapeutic responses. Early clinical trials using individualized neoantigen vaccines for patients with advanced disease had limited clinical efficacy despite demonstrated induction of T cell responses. Therefore, enhancing T cell activity by improving the magnitude, quality and breadth of T cell responses following vaccination is one current goal for improving outcome against metastatic tumours. Another major consideration is how T cells can be further optimized to function within the tumour microenvironment (TME). In this Perspective, we focus on neoantigen vaccines and propose a new approach, termed Vax-Innate, in which vaccination through intravenous delivery or in combination with tumour-targeting immune modulators may improve antitumour efficacy by simultaneously increasing the magnitude, quality and breadth of T cells while transforming the TME into a largely immunostimulatory environment for T cells.

Cancer Vaccines: Recent Insights and Future Directions

The field of cancer immunotherapy has seen incredible advancements in the past decades. mRNA-based cancer vaccines generating de novo T cell responses, particularly against tumor-specific antigens (TSAs), have demonstrated promising clinical outcomes and overcome diverse challenges. Despite the high potential of neoantigens to provide personalized immunotherapies through their tumor specificity and immunogenicity, challenges related to the scarcity of immunogenic neoepitopes have prompted continuous research towards finding new tumor-associated antigens (TAAs) and broader therapeutic frameworks, which may now learn from the genuine successes obtained with neoantigens. As an example, human endogenous retroviruses (HERVs) have emerged as potential alternatives to tumor neoantigens due to their high tumoral expression and ability to elicit both T cell reactivity and B cell responses associated with the efficacy of existing immunotherapies. This review aims to assess the status and limitations of TSA-directed mRNA cancer vaccines and the lessons that can be derived from these and checkpoint inhibitor studies to guide TAA vaccine development. We expect that shared B cell, CD4 and CD8 T cell antigen presentation will be key to stimulate continuous T cell expansion and efficacy for tumors that do not contain pre-existing tertiary lymphoid structures. When these structures are present in highly mutated tumors, the current checkpoint-based immunotherapies show efficacy even in immune privileged sites, and vaccines may hold the key to broaden efficacy to more tumor types and stages.

Abstract PR-07: Optimally designed mRNA vaccine encoding tumor-specific antigens identified in a colorectal cancer model leads to complete tumor rejection in mice

Abstract mRNA vaccines can be designed to encode multiple epitopes of choice, which is a crucial advantage when aiming to include a broad coverage immune response. Upon translation, the cell machinery must process the vaccine-encoded poly-epitope protein to release individual peptides. This processing step is key in inducing an immune response toward selected epitopes, as efficient processing yields a higher amount of peptide available for MHC-I presentation. The efficiency of peptide processing is greatly influenced by the peptide surrounding context (i.e. the flanking amino acids in N-and C-terminal). Aberrantly expressed tumor-specific antigens (aeTSAs) are MHC-I-associated peptides (MAPs) resulting from cancer-specific epigenetic changes and splicing aberrations. In contrast to TSAs derived from mutated protein-coding exons, aeTSAs are highly shared by different tumors. Moreover, unlike commonly used tumor-associated antigens (TAAs), they are not expressed by normal healthy cells, which is pivotal for inducing strong CD8+ T cell responses. The present study aimed to determine whether RNA vaccines encoding aeTSAs would elicit protective anti-tumor responses against a colorectal cancer cell line model (MC38). We hypothesized that multiepitope mRNA vaccine efficacy would be improved if the mRNA construct was composed of minimal epitopes (here, cancer antigens) bordered by optimal (rather than natural) flanking sequences. Thus, we designed 2 vaccine constructs encoding 5 aeTSAs identified by mass spectrometry in MC38 tumor cells. The 2 constructs differ in the identity of the amino acids flanking the antigens (natural vs. substituted antigen flanking sequences). Mice were injected subcutaneously with MC38 cells on Day 0. Three mRNA vaccine doses were administered intravenously one week apart, starting at Day 4. Vaccination with our improved mRNA vaccine design showed a clear therapeutic effect. As opposed to the natural flanking sequences design resulting in delayed tumor growth, vaccination with the substituted flanking sequences design led to the complete elimination of tumors and the survival of all mice. Elispot and dextramer stainings revealed that at least 3 of the 5 MC38 aeTSAs were immunogenic and that the amplitude of antigen-specific CD8+ T cell responses was significantly higher in mice vaccinated with the substituted flanking sequences design. Our results confirm our hypothesis that highly proficient flanking regions have intrinsic benefits that can be carried over to different antigens. From a translational perspective, our work provides new insights into the therapeutic potential of optimally designed aeTSA-encoding mRNA vaccines for treating cancers. Citation Format: Marie-Pierre Hardy, Krystel Vincent, Gabriel Ouellet-Lavallée, Chantal Durette, Isabelle Caron, Joel Lanoix, Mathieu Courcelles, Jean-Philippe Laverdure, Pierre Thibault, Claude Perreault. Optimally designed mRNA vaccine encoding tumor-specific antigens identified in a colorectal cancer model leads to complete tumor rejection in mice [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor Immunology and Immunotherapy; 2024 Oct 18-21; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2024;12(10 Suppl):Abstract nr PR-07.

Targeting overexpressed antigens in glioblastoma via CAR T cells with computationally designed high-affinity protein binders.

Chimeric antigen receptor (CAR) T cells targeting receptors on tumour cells have had limited success in patients with glioblastoma. Here we report the development and therapeutic performance of CAR constructs leveraging protein binders computationally designed de novo to have high affinity for the epidermal growth factor receptor (EGFR) or the tumour-associated antigen CD276, which are overexpressed in glioblastoma. With respect to T cells with a CAR using an antibody-derived single-chain variable fragment as antigen-binding domain, the designed binders on CAR T cells promoted the proliferation of the cells, the secretion of cytotoxic cytokines and their resistance to cell exhaustion, and improved antitumour performance in vitro and in vivo. Moreover, CARs with the binders exhibited higher surface expression and greater resistance to degradation, as indicated by bulk and single-cell transcriptional profiling of the cells. The de novo design of binding domains for specific tumour antigens may potentiate the antitumour efficacy of CAR T cell therapies for other solid cancers.

Photothermal Fe3O4 nanoparticles induced immunogenic ferroptosis for synergistic colorectal cancer therapy

Photothermal therapy (PTT) is a promising non-invasive treatment that has shown great potential in eliminating tumors. It not only induces apoptosis of cancer cells but also triggers immunogenic cell death (ICD) which could activate the immune system against cancer. However, the immunosuppressive tumor microenvironment (TIME) poses a challenge to triggering strong immune responses with a single treatment, thus limiting the therapeutic effect of cancer immunotherapy. In this study, dual-targeted nano delivery system (GOx@FeNPs) combined with αPD-L1 immune checkpoint blocker could inhibit colorectal cancer (CRC) progression by mediating PTT, ferroptosis and anti-tumor immune response. Briefly, specific tumor delivery was achieved by the cyclic arginine glycyl aspartate (cRGD) peptide and anisamide (AA) in GOx@FeNPs which not only had a good photothermal effect to realize PTT and induce ICD, but also could deplete glutathione (GSH) and catalyze the production of reactive oxygen species (ROS) from endogenous H2O2. All these accelerated the Fenton reaction and augmented the process of PTT-induced ICD. Thus, a large amount of tumor specific antigen was released to stimulate the maturation of dendritic cells (DCs) in lymph nodes and enhance the infiltration of CD8+ T cells in tumor. At the same time, the combination with αPD-L1 has favorable synergistic effectiveness against CRC with tumor inhibition rate over 90%. Furthermore, GOx@FeNPs had good magnetic resonance imaging (MRI) capability under T2-weighting owing to the presence of Fe3+, which is favorable for integrated diagnosis and treatment systems of CRC. By constructing a dual-targeted GOx@FeNPs nanoplatform, PTT synergistically combined with ferroptosis was realized to improve the immunotherapeutic effect, providing a new approach for CRC immunotherapy.

Mechanisms and Clinical Applications of Virus-Based Cancer Vaccines

Over the past several decades, immunotherapy as a novel cancer treatment has made tremendous progress. Several categories of immunotherapy have emerged, all designed to stimulate the patients immune system to fight cancer. Cancer vaccines, specifically virus-based cancer vaccines, is a subcategory of immunotherapy that can trigger both innate and adaptive immune response by targeting tumor-specific and tumor-associated antigens. This review summarizes the mechanisms of different types of virus-based cancer vaccines, including inactivated/live attenuated/subunit vaccines, oncolytic virus vaccines, and viral vector vaccines. Furthermore, this review introduces the clinical applications of virus-based cancer vaccines, including oncolytic virus vaccine T-VEC against metastasized melanoma, and Pexa-Vec and PROSTVAC that are currently in clinical trials. Virus-based cancer vaccines have shown encouraging results in numerous studies in enhancing overall survival, relapse-free survival, and overall response rate among patients with solid tumors. This review underscores the necessity for future research aimed at improving the efficacy of virus-based cancer vaccines and investigating combination therapies with other immunotherapies to achieve optimal treatment outcomes.

A comprehensive proteogenomic pipeline for neoantigen discovery to advance personalized cancer immunotherapy.

The accurate identification and prioritization of antigenic peptides is crucial for the development of personalized cancer immunotherapies. Publicly available pipelines to predict clinical neoantigens do not allow direct integration of mass spectrometry immunopeptidomics data, which can uncover antigenic peptides derived from various canonical and noncanonical sources. To address this, we present an end-to-end clinical proteogenomic pipeline, called NeoDisc, that combines state-of-the-art publicly available and in-house software for immunopeptidomics, genomics and transcriptomics with in silico tools for the identification, prediction and prioritization of tumor-specific and immunogenic antigens from multiple sources, including neoantigens, viral antigens, high-confidence tumor-specific antigens and tumor-specific noncanonical antigens. We demonstrate the superiority of NeoDisc in accurately prioritizing immunogenic neoantigens over recent prioritization pipelines. We showcase the various features offered by NeoDisc that enable both rule-based and machine-learning approaches for personalized antigen discovery and neoantigen cancer vaccine design. Additionally, we demonstrate how NeoDisc's multiomics integration identifies defects in the cellular antigen presentation machinery, which influence the heterogeneous tumor antigenic landscape.

Tumor-specific antigen delivery for T-cell therapy via a pH-sensitive peptide conjugate.

Identifying an optimal antigen for targeted cancer therapy is challenging as the antigen landscape on cancerous tissues mimics that of healthy tissues, with few unique tumor-specific antigens identified in individual patients. pH low insertion peptides (pHLIPs) act as a unique delivery platform that can specifically target the acidic microenvironment of tumors, sparing healthy tissue in the process. We developed a pHLIP-peptide conjugate to deliver the SIINFEKL peptide, an immunogenic fragment of ovalbumin, to tumor cells in vivo. When processed intracellularly, SIINFEKL is presented for immune recognition through the major histocompatibility complex (MHC) class I pathway. We observed selective delivery of pHLIP-SIINFEKL both in vitro and in vivo using fluorescently labeled constructs. In vitro, treatment of melanoma tumor cells with pHLIP-SIINFEKL resulted in recognition by SIINFEKL-specific T cells (OT1), leading to T cell activation and effector function. Mechanistically, we show that this recognition by OT1 cells was abrogated by siRNA/shRNA knockdown of multiple components within the MHC class I pathway in the target tumor cells, indicating that an intact antigen processing pathway in the cancer cells is necessary to mediate the effect of pHLIP-directed SIINFEKL delivery. In vivo, pHLIP-SIINFEKL treatment of tumor-bearing mice resulted in recruitment of OT1 T cells and suppression of tumor growth in two syngeneic tumor models in immunocompetent mice, with no effect when mutating either the pHLIP or SIINFEKL components of the conjugate. These results suggest that pHLIP-mediated peptide delivery can be used to deliver novel artificial antigens that can be targeted by cell-based therapies.

Innovative Cancer Immunotherapy with MAGE-A3 mRNA Cancer Vaccines.

Cancer causes over 10 million deaths annually worldwide and remains a significant global health challenge. This study investigated advanced immunotherapy strategies, focusing on mRNA vaccines that target tumor-specific antigens to activate the immune system. We developed a novel mRNA vaccine using O,O'-dimyristyl-N-lysyl aspartate (DMKD) to improve stability and phosphatidylserine (PS) to enhance antigen presentation to immune cells. This vaccine, containing melanoma-associated antigen A3 (MAGE-A3) mRNA encapsulated within lipid nanoparticles (LNPs), was evaluated for its therapeutic potential against colorectal cancer. Our findings demonstrated that MAGE-A3 mRNA-containing DMKD-PS LNPs significantly reduced tumor size and weight, effectively combating metastatic cancer. The vaccine elicited a robust immune response, increasing specific immunoglobulin and cytokine levels without causing histotoxicity in major organs. These results confirm that the DMKD-PS-based MAGE-A3 mRNA vaccine holds promise for cancer prevention and treatment.

Dual-drug loaded manganese dioxide nanoparticles coated with bacterial outer-membrane vesicles for chemo-immunotherapy in lung cancer

Lung cancer is the most leading cause of cancer death. Traditional chemotherapy has unavoidable drawbacks of nonspecific tumor targeting, high toxicity, and poor therapeutic efficiency. Nanocarriers can achieve accurate delivery and reduce adverse reactions of drugs, which have received extensive attention. In this work, hollow manganese dioxide (HMnO2) nanoparticle (NP) that is highly responsive to tumor microenvironment, was simultaneously loaded with paclitaxel (PTX), a chemotherapy drug, and imiquimod (R837), a toll-like receptor 7 agonist. Those NPs were then coated with bacterial outer-membrane vesicles (OMVs-HMnO2@PTX + R837 NPs), whose surface proteins could act as tumor-specific antigens. The obtained nanovaccine inherited superior tumor-targeting capacity of OMVs and promoted retention in tumors. As a result, intravenous injection of the nanovaccine led to remarkable tumor growth inhibition. Furthermore, we found that the nanovaccine effectively boosted dendritic cells maturation and increased cytotoxic T lymphocytes infiltration. Taken together, these results demonstrated the great potential in applying OMVs-enveloped nano-activator in cancer chemo-immunotherapy.

Potential tumor-specific antigens and immune landscapes identification for mRNA vaccine in thyroid cancer.

Tumor mRNA vaccines have been identified as a promising technology for cancer therapy in multiple cancer types, while their efficacy in thyroid cancer (THCA) is unclear. Immunotyping is strongly associated with the immune microenvironment and immune status in cancer, thus it is important in vaccination and therapeutic response. This study is to identify potential valuable antigens and novel immune subtypes of THCA for immune landscape construction, thus screening patients suitable for mRNA vaccination. The clinical information and gene expression files of 568 THCA cases were obtained from the TCGA dataset. The DNA copy number variation and the somatic mutation of THCA were visualized by the cBioPortal database. TIMER was used to investigate the immune infiltrating correlation with candidate antigens. Consensus clustering analysis was conducted to cluster data using the ConsensusClusterPlus package. The immune landscapes of THCA patients were visualized using the Monocle package. The critical hub genes for THCA mRNA vaccines were identified by WGCNA package. To validate, the immunohistochemistry and real-time quantitative PCR (RT-qPCR) were performed to detect the expression level of potential antigen for mRNA vaccine in tissue and cell lines in THCA. Thymidine kinase 1 (TK1) was identified as a potential biomarker of mRNA vaccine against THCA. It was confirmed to be significantly upregulated in THCA tissues and cells lines. Moreover, three novel immune subtypes of THCA were obtained based on the expression consistency of immune-associated genes. The S2 subtype was characterized as an immunological "cold" phenotype with a high expression of immunogenic cell death modulators. S1 and S3 subtypes were immunological "hot" phenotypes with immune checkpoints upregulation. Further, the immune landscape of THCA patients was visualized and ten hub genes for mRNA vaccines were identified. TK1 was a tumor-specific antigen of mRNA vaccines. The patients belonging to the S2 subtype ("cold" tumor) were suitable for mRNA vaccine therapy in THCA. Notably, ten hub genes were conducted as potential biomarkers for identifying suitable patients for mRNA vaccination. These findings provided novel insights into mRNA vaccine development against THCA.

Immunogenicity regulation of genetically engineered vaccine and its potential in tumor treatment

In this study, the strategy of enhancing immunogenicity of genetically engineered vaccine and its application potential in tumor treatment were discussed. Firstly, the study explained the principle that genetic engineering vaccine designed antigen by gene recombination technology to trigger strong immune response. By adjusting gene combination, improving vaccine delivery system and using adjuvant, the immune stimulation ability and delivery efficiency of vaccine were improved. Especially in tumor therapy, these vaccines stimulate specific immune responses against specific or related tumor antigens. This paper also summarizes the clinical manifestations of mRNA cancer vaccine and individualized cancer vaccine, and discusses the combined application with traditional treatment methods such as chemotherapy, radiotherapy, targeted therapy and immune checkpoint inhibitors, in order to improve the treatment effect and the diversity of patients' treatment options.

Revolutionizing Cancer Treatment: Recent Advances in Immunotherapy.

Cancer immunotherapy has emerged as a transformative approach in oncology, utilizing the body's immune system to specifically target and destroy malignant cells. This review explores the scope and impact of various immunotherapeutic strategies, including monoclonal antibodies, chimeric antigen receptor (CAR)-T cell therapy, checkpoint inhibitors, cytokine therapy, and therapeutic vaccines. Monoclonal antibodies, such as Rituximab and Trastuzumab, have revolutionized treatment paradigms for lymphoma and breast cancer by offering targeted interventions that reduce off-target effects. CAR-T cell therapy presents a potentially curative option for refractory hematologic malignancies, although challenges remain in effectively treating solid tumors. Checkpoint inhibitors have redefined the management of cancers like melanoma and lung cancer; however, managing immune-related adverse events and ensuring durable responses are critical areas of focus. Cytokine therapy continues to play a vital role in modulating the immune response, with advancements in cytokine engineering improving specificity and reducing systemic toxicity. Therapeutic vaccines, particularly mRNA-based vaccines, represent a frontier in personalized cancer treatment, aiming to generate robust, long-lasting immune responses against tumor-specific antigens. Despite these advancements, the field faces significant challenges, including immune resistance, tumor heterogeneity, and the immunosuppressive tumor microenvironment. Future research should address these obstacles through emerging technologies, such as next-generation antibodies, Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)-based gene editing, and AI-driven drug discovery. By integrating these novel approaches, cancer immunotherapy holds the promise of offering more durable, less toxic, and highly personalized treatment options, ultimately improving patient outcomes and survival rates.

Long-range alternative splicing contributes to neoantigen specificity in glioblastoma.

Recent advances in neoantigen research have accelerated the development of immunotherapies for cancers, such as glioblastoma (GBM). Neoantigens resulting from genomic mutations and dysregulated alternative splicing have been studied in GBM. However, these studies have primarily focused on annotated alternatively-spliced transcripts, leaving non-annotated transcripts largely unexplored. Circular ribonucleic acids (circRNAs), abnormally regulated in tumors, are correlated with the presence of non-annotated linear transcripts with exon skipping events. But the extent to which these linear transcripts truly exist and their functions in cancer immunotherapies remain unknown. Here, we found the ubiquitous co-occurrence of circRNA biogenesis and alternative splicing across various tumor types, resulting in large amounts of long-range alternatively-spliced transcripts (LRs). By comparing tumor and healthy tissues, we identified tumor-specific LRs more abundant in GBM than in normal tissues and other tumor types. This may be attributable to the upregulation of the protein quaking in GBM, which is reported to promote circRNA biogenesis. In total, we identified 1057 specific and recurrent LRs in GBM. Through in silico translation prediction and MS-based immunopeptidome analysis, 16 major histocompatibility complex class I-associated peptides were identified as potential immunotherapy targets in GBM. This study revealed long-range alternatively-spliced transcripts specifically upregulated in GBM may serve as recurrent, immunogenic tumor-specific antigens.

Revolutionizing Cancer Treatments through Stem Cell-Derived CAR T Cells for Immunotherapy: Opening New Horizons for the Future of Oncology.

Recent advances in cellular therapies have paved the way for innovative treatments of various cancers and autoimmune disorders. Induced pluripotent stem cells (iPSCs) represent a remarkable breakthrough, offering the potential to generate patient-specific cell types for personalized as well as allogeneic therapies. This review explores the application of iPSC-derived chimeric antigen receptor (CAR) T cells, a cutting-edge approach in allogeneic cancer immunotherapies. CAR T cells are genetically engineered immune cells designed to target specific tumor antigens, and their integration with iPSC technology holds immense promise for enhancing the efficacy, safety, and scalability of cellular therapies. This review begins by elucidating the principles behind iPSC generation and differentiation into T cells, highlighting the advantage of iPSCs in providing a uniform, inexhaustible source of CAR T cells. Additionally, we discuss the genetic modification of iPSC-derived T cells to express various CARs, emphasizing the precision and flexibility this affords in designing customized therapies for a diverse range of malignancies. Notably, iPSC-derived CAR T cells demonstrate a superior proliferative capacity, persistence, and anti-tumor activity compared to their conventionally derived counterparts, offering a potential solution to challenges associated with conventional CAR T cell therapies. In conclusion, iPSC-derived CAR T cells represent a groundbreaking advancement in cellular therapies, demonstrating unparalleled potential in revolutionizing the landscape of immunotherapies. As this technology continues to evolve, it holds the promise of providing safer, more effective, and widely accessible treatment options for patients battling cancer and other immune-related disorders. This review aims to shed light on the transformative potential of iPSC-derived CAR T cells and inspire further research and development in this dynamic field.

Disruptions in antigen processing and presentation machinery on sarcoma

BackgroundThe antigen processing machinery (APM) plays a critical role in generating tumor-specific antigens that can be recognized and targeted by the immune system. Proper functioning of APM components is essential for presenting these antigens on the surface of tumor cells, enabling immune detection and destruction. In many cancers, defects in APM can lead to immune evasion, contributing to tumor progression and poor clinical outcomes. However, the status of the APM in sarcomas is not well characterized, limiting the development of effective immunotherapeutic strategies for these patients.MethodsWe investigated 126 patients with 8 types of bone and soft tissue sarcoma operated between 2001–2021. Tissue microarrays mapped 11 specific areas in each case. The presence/absence of APM protein was determined through immunohistochemistry. Bayesian networks were used.ResultsAll investigated sarcomas had some defects in APM. The least damaged component was HLA Class I subunit β2-microglobulin and HLA Class II. The proteasome LMP10 subunit was defective in leiomyosarcoma (LMS), myxoid liposarcoma (MLPS), and dedifferentiated liposarcoma (DDLPS), while MHC I transporting unit TAP2 was altered in undifferentiated pleomorphic sarcoma (UPS), gastrointestinal stromal tumor (GIST), and chordoma (CH). Among different neoplastic areas, high-grade areas showed different patterns of expression compared to high lymphocytic infiltrate areas. Heterogeneity at the patient level was also observed. Loss of any APM component was prognostic of distant metastasis (DM) for LMS and DDLPS and of overall survival (OS) for LMS.ConclusionSarcomas exhibit a high degree of defects in APM components, with differences among histotypes and tumoral areas. The most commonly altered APM components were HLA Class I subunit β2-microglobulin, HLA Class I subunit α (HC10), and MHC I transporting unit TAP2. The loss of APM components was prognostic of DM and OS and clinically relevant for LMS and DDLPS. This study explores sarcoma molecular mechanisms, enriching personalized therapeutic approaches.

Exploring the potential of the convergence between extracellular vesicles and CAR technology as a novel immunotherapy approach.

Cancer therapy is a dynamically evolving field, witnessing the emergence of innovative approaches that offer a promising outlook for patients grappling with persistent disease. Within the realm of therapeutic exploration, chimeric antigen receptor (CAR) T cells as well as CAR NK cells, have surfaced as novel approaches, each possessing unique attributes and transformative potential. Immune cells engineered to express CARs recognizing tumour-specific antigens, have shown remarkable promise in treating terminal cancers by combining the precision of antibody specificity with the potent cytotoxic function of T cells. However, their application in solid tumours is still in its nascent stages, presenting unique major challenges. On the same note, CAR NK cells offer a distinct immunotherapeutic approach, utilizing CARs on NK cells, providing advantages in safety, manufacturing simplicity, and a broader scope for cancer treatment. Extracellular vesicles (EVs) have emerged as promising therapeutic agents due to their ability to carry crucial biomarkers and biologically active molecules, serving as vital messengers in the intercellular communication network. In the context of cancer, the therapeutic potential of EVs lies in delivering tumour-suppressing proteins, nucleic acid components, or targeting drugs with precision, thereby redefining the paradigm of precision medicine. The fusion of CAR technology with the capabilities of EVs has given rise to a new therapeutic frontier. CAR T EVs and CAR NK EVs, leveraging the power of EVs, have the potential to alleviate challenges associated with live-cell therapies. EVs are suggested to reduce the side effects linked to CAR T cell therapy and hold the potential to revolutionize the penetrance in solid tumours. EVs act as carriers of pro-apoptotic molecules and RNA components, enhancing immune responses and thereby expanding their therapeutic potential. In this review article, we navigate dynamic landscapes, with our objective being to evaluate comparative efficacy, safety profiles, manufacturing complexities, and clinical applicability.

CD28 hinge used in chimeric antigen receptor (CAR) T-cells exhibits local structure and conformational exchange amidst global disorder

T-cell therapies based on chimeric antigen receptor (CAR) targeting of a tumor-specific antigen offer hope for patients with relapsed or refractory cancers. CAR hinge and transmembrane regions link antigen recognition domains to intracellular signal transduction domains. Here, we apply biophysical methods to characterize the structure and dynamic properties of the CD28 CAR hinge (CD28H) used in an FDA-approved CD19 CAR for the treatment of B-lineage leukemia/lymphoma. By using nuclear Overhauser effect spectroscopy (NOESY), which detects even transiently occupied structural motifs, we observed otherwise elusive local structural elements amidst overall disorder in CD28H, including a conformational switch from a native β-strand to a 310-helix and polyproline II helix-like structure. These local structural motifs contribute to an overall loosely formed extended geometry that could be captured by NOESY data. All FDA-approved CARs use prolines in the hinge region, which we find in CD28, and previously in CD8α, isomerize to promote structural plasticity and dynamics. These local structural elements may function in recognition and signaling events and constrain the spacing between the transmembrane and antigen recognition domains. Our study thus demonstrates a method for detecting local and transient structure within intrinsically disordered systems and moreover, our CD28H findings may inform future CAR design.