The emerging field of oncolytic virus-based cancer immunotherapy

Antitumor and immunomodulatory activities of diphyllin and its derivatives

Immune surveillance plays a key role in controlling tumor formation and development, and immune cell-based therapies, such as chimeric antigen receptor (CAR)-T cells and CAR-natural killer (NK) cells, have become important for the treatment of cancer. The proton pump (PP), vacuolar H+-ATPase (V-ATPase), acidifies intracellular organelles, pumps protons across the cell plasma membranes, and regulates the activity of various signaling pathways, and thus has been regarded as a potential target for cancer treatment. In addition, V-ATPase plays an important role in cytotoxic T lymphocytes, extracellular vesicle (EV) endocytosis, innate immune responses (IIR), and phagocytosis and hence has the potential to function as a target for the enhancement of immunotherapy. As potent V-ATPase inhibitors, the arylnaphthalene lignans, diphyllin and its derivatives, have exhibited potent antitumor and immunomodulatory activities. The structurally related aryltetralin lignan, podophyllotoxin, has served as a lead compound for both etoposide and teniposide, which have been developed as effective anticancer agents. In the present review, the role of V-ATPase in cancer immunotherapy and the structure-activity relationships (SARs) of diphyllin and its cytotoxic and V-ATPase inhibitory activities and the mechanisms of action are discussed. Also, the promise of diphyllin and its derivatives in the development of new adjuvants for cancer immunotherapies has been proposed.

Phase 1, open-label, multicenter, dose escalation safety and tolerability study of oncolytic virus OVV-01 in advanced solid tumors

BACKGROUND

OVV-01 is a genetically engineered vesicular stomatitis virus oncolytic virus designed to selectively amplify in tumor cells and express tumor-associated antigen NY-ESO-1. This study was designed to evaluate the safety, tolerability, and efficacy of OVV-01 in patients with advanced solid tumors.

METHODS

This is a phase 1, first-in-human, open-label, multicenter study of OVV-01 in patients with advanced solid tumors. OVV-01 was intratumorally injected biweekly (every two weeks, Q2W), 3 weeks after the first dose for a total of six doses. Dose escalation follows a 3+3 design at four doses of 6×107 Plaue-Forming Unit (PFU), 6×108 PFU, 6×109 PFU, and 1.2×1011 PFU. The primary endpoints were safety and tolerability. The second endpoints included overall response rate (ORR) and disease control rate (DCR) of OVV-01, by investigators per Response Evaluation Criteria in Solid Tumors V.1.1.

RESULTS

18 patients were enrolled into four dose groups, among whom 6 were soft tissue sarcoma (STS). No dose-limiting toxicities and treatment-related severe adverse events were observed. 11 patients were evaluated for efficacy, and the ORR was 27.3%, and the DCR was 63.6%. Among the four evaluable patients with advanced STS, the ORR was 75%. Two patients with STS achieved CR at doses above 6.0×109 PFU.

CONCLUSIONS

The intratumor injection of OVV-01 was safe and well-tolerated in patients with advanced solid tumors. A significant response was observed in patients with STS.

TRIAL REGISTRATION NUMBER

NCT04787003.

Plasma proteins and herpes simplex virus infection: a proteome-wide Mendelian randomization study

Proteomics plays a pivotal role in clinical diagnostics and monitoring. We conducted proteome-wide Mendelian randomization (MR) study to estimate the causal association between plasma proteins and Herpes simplex virus (HSV) infection. Data for 2,923 plasma protein levels were obtained from a large-scale protein quantitative trait loci study involving 54,219 individuals, conducted by the UK Biobank Pharma Proteomics Project. HSV-associated SNPs were derived from the FinnGen study, which included a total of 400,098 subjects infected with HSV. MR analysis was performed to assess the links between protein levels and the risk of HSV infection. Furthermore, a Phenome-wide MR analysis was utilized to explore potential alternative indications or predict adverse drug events. Finally, we evaluated the impact of 1,949 plasma proteins on HSV infection, identifying 48 proteins that were negatively associated with HSV infection and 54 proteins that were positively associated. Genetically higher HLA-E levels were significantly associated with increased HSV infection risk (OR = 1.39, 95% CI: 1.17-1.65, P = 2.13 × 10-4, while ULBP2 showed a significant negative association with HSV infection risk (OR = 0.81, 95% CI: 0.73-0.90, P = 6.25 × 10-5) in the primary analysis. No significant heterogeneity or pleiotropy was observed in any of the results. Additionally, we found a suggestive association of Lymphotoxin-beta, SMOC1, MICB_MICA, ASGR1, and ANXA10 with HSV infection risk (P < 0.003). In Phenome-wide MR analysis, HLA-E was associated with 214 phenotypes (PFDR < 0.10) while ULBP2 did not show significant associations with any diseases after FDR adjustment. The comprehensive MR analysis established a causal link between multiple plasma proteins and HSV infection, emphasizing the roles of HLA-E and ULBP2. These results provide new insights into the biological mechanisms of HSV and support the potential for early intervention and treatment strategies, although further research is needed to validate these plasma protein biomarkers.

VSV-CHIKV activates antitumor immunity by inducing pyroptosis in a melanoma model

Melanoma is the most dangerous skin cancer due to its difficulty in treatment, high recurrence rate and metastatic ability. As a vector for oncolytic viruses (OVs), vesicular stomatitis virus (VSV) has been shown to be effective against malignant melanoma. However, the glycoprotein G protein of VSV has potential neurotoxicity. It has been shown that replacing glycoprotein G with E3-E2-6K-E1 of chikungunya virus (CHIKV) reduces its neurotoxicity and targets gliomas. Therefore, the aim of this study was to investigate the oncolytic effect of recombinant VSV-CHIKV on melanoma and the underlying mechanism. In this study, we found that recombinant VSV-CHIKV triggered GSDMD-mediated melanoma cell pyroptosis. Importantly, the NLRP3/Caspase-1/GSDMD axis was activated after VSV-CHIKV infection in melanoma cell lines and in a xenograft mouse model. Inhibition of GSDMD blocked cell pyroptosis, antitumor immunity and the tumor response in response to VSV-CHIKV treatment, suggesting that VSV-CHIKV act through the GSDMD pathway. VSV-CHIKV-triggered GSDMD-mediated tumor pyroptosis recruited cytotoxic T lymphocytes (CTLs) into the tumor microenvironment, which was accompanied by the release of inflammatory mediators. This remodeled the tumor microenvironment and turned immunologically "cold" tumors into "hot" tumors, thereby sensitized these tumors to checkpoint blockade. Finally, the combination therapy of VSV-CHIKV and an immune checkpoint inhibitor (anti-PD-1) prolonged the survival of mice. In conclusion, the VSV-CHIKV strategy is an attractive biologic therapy against melanoma.

Immunotherapy in microsatellite-stable colorectal cancer: Strategies to overcome resistance

Colorectal cancer (CRC) is among the foremost causes of cancer-related mortality worldwide; however, individuals with microsatellite-stable (MSS) disease-who constitute most CRC diagnoses-derive limited benefit from existing immunotherapeutic approaches. Here, we outline emerging methods designed to address the inherent resistance of MSS CRC to immune checkpoint inhibitors (ICIs). Recent findings emphasize how the immunosuppressive tumor microenvironment (TME) in MSS CRC, marked by diminished immunogenicity and high levels of regulatory T cells and myeloid-derived suppressor cells, restricts effective antitumor immune activity. Combination regimens that merge ICIs with chemotherapy, anti-angiogenic agents, or targeted blockade of pathways such as TGF-β and VEGF have shown encouraging early outcomes, including enhanced antigen presentation and T-cell penetration. Novel immunomodulatory platforms-such as epigenetic modifiers, oncolytic viruses, and engineered probiotic vaccines-are under assessment to further reprogram the TME and boost therapeutic efficacy. Concurrently, progress in adoptive cell therapies (for example, chimeric antigen receptor (CAR) T cells) and the development of cancer vaccines targeting tumor-associated and neoantigens promise to extend immune control over MSS CRC. In parallel, improving patient selection through predictive biomarkers-from circulating tumor DNA (ctDNA) to gene expression signatures and specific molecular subtypes-could refine individualized treatment strategies. Finally, interventions that alter the gut microbiome, including probiotics and fecal transplantation, serve as complementary tools to strengthen ICI responses. Taken together, these insights and combined treatment strategies lay the foundation for more successful immunotherapeutic interventions in MSS CRC, ultimately aiming to provide sustained clinical benefits to a broader spectrum of patients.

Glioblastoma-instructed astrocytes suppress tumour-specific T cell immunity

Glioblastoma is the most common and aggressive primary brain cancer and shows minimal response to therapies. The immunosuppressive tumour microenvironment in glioblastoma contributes to the limited therapeutic response. Astrocytes are abundant in the central nervous system and have important immunoregulatory roles. However, little is known about their role in the immune response to glioblastoma1. Here we used single-cell and bulk RNA sequencing of clinical glioblastoma samples and samples from preclinical models, multiplexed immunofluorescence, in vivo CRISPR-based cell-specific genetic perturbations and in vitro mouse and human experimental systems to address this gap in knowledge. We identified an astrocyte subset that limits tumour immunity by inducing T cell apoptosis through the death receptor ligand TRAIL. Moreover, we identified that IL-11 produced by tumour cells is a driver of STAT3-dependent TRAIL expression in astrocytes. Astrocyte signalling through STAT3 and TRAIL expression were associated with a shorter time to recurrence and overall decreased survival in patients with glioblastoma. Genetic inactivation of the IL-11 receptor or TRAIL in astrocytes extended survival in mouse models of glioblastoma and enhanced T cell and macrophage responses. Finally, treatment with an oncolytic HSV-1 virus engineered to express a TRAIL-blocking single-chain antibody in the tumour microenvironment extended survival and enhanced tumour-specific immunity in preclinical models of glioblastoma. In summary, we establish that IL-11-STAT3-driven astrocytes suppress glioblastoma-specific protective immunity by inducing TRAIL-dependent T cell apoptosis, and engineered therapeutic viruses can be used to target this mechanism of astrocyte-driven tumour immunoevasion.

Combination therapies and novel delivery systems: a new frontier in overcoming TRAIL resistance in gastric cancer

Gastric cancer (GC) presents a formidable challenge in oncology, mainly due to its inherent resistance to therapies such as tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). This review delineates the multifaceted mechanisms underlying TRAIL resistance in GC, encompassing the deregulation of death receptors (DRs) and decoy receptors (DcRs), aberrant signaling pathways, and the influence of the tumor microenvironment (TME). Innovative strategies such as nanoparticle-based drug delivery systems and oncolytic viral therapies are being explored to counteract these challenges. Nanoparticles enhance TRAIL delivery and efficacy by exploiting the enhanced permeability and retention (EPR) effect, while oncolytic viruses can selectively target cancer cells and stimulate immune responses. Combination therapies, integrating TRAIL with conventional chemotherapeutics like paclitaxel, cisplatin, and 5-fluorouracil, have shown promise in overcoming resistance by modulating apoptotic pathways and downregulating multidrug resistance genes. Additionally, novel agents like cyclopamine, decitabine, and genistein have emerged as effective TRAIL sensitizers by modulating apoptotic pathways and enhancing DR5 expression. Furthermore, the integration of epigenetic modifiers can restore TRAIL sensitivity by demethylating DR4 and DR5 genes. This review emphasizes the need for a comprehensive understanding of the molecular underpinnings of TRAIL resistance and the potential of combination therapies and TRAIL delivery by nanoparticles and oncolytic viruses to enhance treatment outcomes in GC. Future research should focus on elucidating predictive biomarkers and optimizing therapeutic regimens to improve the clinical efficacy of TRAIL-based strategies in GC.

Oncolytic Adenovirus Armoring with CXCL9 and IL15 Shows Potent Antitumor Activity and Boosts CAR-T Therapy for Prostate Cancer

Chimeric antigen receptor T cell (CAR-T) therapy has achieved great success and progress for treatment of hematological malignancy, but it still cannot overcome the obstacles in solid tumors. The hostile tumor microenvironment (TME), such as dense extracellular matrix, hypoxia, low pH, and tumor-derived metabolites, largely impedes CAR-T function. Oncolytic virus, as a form of immunotherapy, provides a way to antagonize the TME and improve the efficacy of CAR-T cells in solid tumors. In this study, the chemokine CXCL9 and interleukin 15 (IL15) genes were genetically integrated into adenoviral vector to construct oncolytic adenovirus (OAV) Ad-CXCL9-IL15, which could infect tumor cells to express and secrete CXCL9 and IL15. Ad-CXCL9-IL15 showed potent antitumor activity in xenografted prostate cancer model and augmented the tumor infiltration of CD45+CD3+ T and CD8+ T cells in immunocompetent mice. Moreover, Ad-CXCL9-IL15 treatment decreased Treg cells in tumor mass and increased CD44+CD62L+ T cells in spleen. Indicating that Ad-CXCL9-IL15 modified the TME and augmented antitumor immune responses in vivo. Furthermore, administration of Ad-CXCL9-IL15 dramatically promoted infiltration and survival of B7H3-targeting CAR-T cells, improved the therapeutic efficacy, and prolonged the survival time of prostate cancer-bearing mice. Therefore, cytokine-armored OAV Ad-CXCL9-IL15 could be used as a bioenhancer to modify TME and boost immunotherapy for solid tumors.

Oncolytic viruses as cancer therapeutics: From mechanistic insights to clinical translation

Oncolytic virotherapy is a therapeutic approach that leverages genetically engineered or naturally occurring viruses to selectively target and destroy cancer cells while sparing normal tissues. This review provides an overview of the mechanisms of action by oncolytic viruses (OVs), including direct oncolysis, immune activation, and tumor microenvironment (TME) modulation. Despite significant progress, challenges such as immune resistance, tumor evasion mechanisms, and delivery barriers continue to limit the efficacy of OVs. To address these obstacles, recent advances in OV engineering have focused on arming viruses with immunomodulatory molecules, utilizing tumor-specific promoters, and employing CRISPR-based genome editing. Emerging strategies, such as dual-targeting OVs and viral enhancer drugs, have demonstrated promising potential in preclinical and clinical settings. This review also highlights findings from recent clinical trials, underscoring the translational challenges in scaling OVs for widespread therapeutic application. By exploring these innovations and their implications, we aim to shed light on the future directions of oncolytic virotherapy and its transformative potential in cancer treatment.

Advances in cancer immunotherapy: historical perspectives, current developments, and future directions

Cancer immunotherapy, encompassing both experimental and standard-of-care therapies, has emerged as a promising approach to harnessing the immune system for tumor suppression. Experimental strategies, including novel immunotherapies and preclinical models, are actively being explored, while established treatments, such as immune checkpoint inhibitors (ICIs), are widely implemented in clinical settings. This comprehensive review examines the historical evolution, underlying mechanisms, and diverse strategies of cancer immunotherapy, highlighting both its clinical applications and ongoing preclinical advancements. The review delves into the essential components of anticancer immunity, including dendritic cell activation, T cell priming, and immune surveillance, while addressing the challenges posed by immune evasion mechanisms. Key immunotherapeutic strategies, such as cancer vaccines, oncolytic viruses, adoptive cell transfer, and ICIs, are discussed in detail. Additionally, the role of nanotechnology, cytokines, chemokines, and adjuvants in enhancing the precision and efficacy of immunotherapies were explored. Combination therapies, particularly those integrating immunotherapy with radiotherapy or chemotherapy, exhibit synergistic potential but necessitate careful management to reduce side effects. Emerging factors influencing immunotherapy outcomes, including tumor heterogeneity, gut microbiota composition, and genomic and epigenetic modifications, are also examined. Furthermore, the molecular mechanisms underlying immune evasion and therapeutic resistance are analyzed, with a focus on the contributions of noncoding RNAs and epigenetic alterations, along with innovative intervention strategies. This review emphasizes recent preclinical and clinical advancements, with particular attention to biomarker-driven approaches aimed at optimizing patient prognosis. Challenges such as immunotherapy-related toxicity, limited efficacy in solid tumors, and production constraints are highlighted as critical areas for future research. Advancements in personalized therapies and novel delivery systems are proposed as avenues to enhance treatment effectiveness and accessibility. By incorporating insights from multiple disciplines, this review aims to deepen the understanding and application of cancer immunotherapy, ultimately fostering more effective and widely accessible therapeutic solutions.

Advances and challenges in cancer immunotherapy: Strategies for personalized treatment

Cancer immunotherapy has transformed oncology by harnessing the immune system to specifically target cancer cells, offering reduced systemic toxicity compared to traditional therapies. This review highlights key strategies, including adoptive cell transfer (ACT), immune checkpoint inhibitors, oncolytic viral (OV) therapy, monoclonal antibodies (mAbs), and mRNA-based vaccines. ACT reinfuses enhanced immune cells like tumor-infiltrating lymphocytes (TILs) to combat refractory cancers, while checkpoint inhibitors (eg, PD-1 and CTLA-4 blockers) restore T-cell activity. OV therapy uses engineered viruses (eg, T-VEC) to selectively lyse cancer cells, and advanced mAbs improve targeting precision. mRNA vaccines introduce tumor-specific antigens to trigger robust immune responses. Despite significant progress, challenges like immune-related side effects, high costs, and immunosuppressive tumor microenvironments persist. This review underscores the need for combination strategies and precision medicine to overcome these barriers and maximize the potential of immunotherapy in personalized cancer treatment.

Navigating the Purification Process: Maintaining the Integrity of Replication-Competent Enveloped Viruses

Replication-competent virus particles hold significant therapeutic potential in application as oncolytic viruses or cancer vaccines. Ensuring the viral integrity of these particles is crucial for their infectivity, safety, and efficacy. Enveloped virus particles, in particular, offer large gene insert capacities and customizable target specificity. However, their sensitivity to environmental factors presents challenges in bioprocessing, potentially compromising high quality standards and cost-effective production. This review provides an in-depth analysis of the purification process steps for replication-competent enveloped virus particles, emphasizing the importance of maintaining viral integrity. It evaluates bioprocessing methods from cell culture harvest to final sterile filtration, including centrifugation, chromatographic, and filtration purification techniques. Furthermore, the manuscript delves into formulation and storage strategies necessary to preserve the functional and structural integrity of virus particles, ensuring their long-term stability and therapeutic efficacy. To assess the impact of process steps on particles and determine their quality and integrity, advanced analytical methods are required. This review evaluates commonly used methods for assessing viral integrity, such as infectious titer assays, total virus particle quantification, and structural analysis. By providing a comprehensive overview of the current state of bioprocessing for replication-competent enveloped virus particles, this review aims to guide researchers and industry professionals in developing robust and efficient purification processes. The insights gained from this analysis will contribute to the advancement of virus-based therapeutics, ultimately supporting the development of safe, effective, and economically viable treatments for various diseases.

Advances in the Drug Development and Quality Evaluation Principles of Oncolytic Herpes Simplex Virus

Oncolytic herpes simplex virus (oHSV) represents a promising therapeutic approach to treating cancers by virtue of its selective replication in and lysis of tumor cells, with stimulation of host antitumor immunity. At present, four OV drugs have been approved for the treatment of cancers worldwide, two of which are oHSV drugs that have received extensive attention, known as T-VEC and Delytact. This review discusses the history, mechanism of action, clinical development, quality control, and evaluation principles of oHSV products, including viral species and genetic modifications that have improved these products' therapeutic potential, limitations, and future directions. Integration of oHSVs with immunotherapeutic agents and conventional therapies has a promising future in the field of treatment of malignant tumors. Although much progress has been achieved, there is still much work to be done regarding the optimization of treatment protocols and the quality control of oncolytic virus drugs. The approval of various oncolytic virus therapies underlines their clinical relevance, safety, and efficacy, thereby paving the way for further research aimed at overcoming the existing limitations and enhancing patient responses.

Harnessing Oncolytic Viruses for Targeted Therapy in Triple-Negative Breast Cancer

Breast cancer is the most prevalent malignant tumor among women, with triple-negative breast cancer (TNBC) being one of the most aggressive forms due to its high invasiveness and metastatic potential. Traditional treatments such as endocrine therapy and anti-HER2-targeted therapy are largely ineffective for TNBC, and while chemotherapy shows some promise, resistance remains a significant hurdle. Recently, there has been increasing interest in biological therapies, especially oncolytic viruses (OVs). OVs promote anti-tumor effects by selectively killing tumor cells and stimulating immune responses, and have achieved notable breakthroughs in breast cancer treatment. OVs have demonstrated effectiveness comparable to surgery, radiotherapy, or chemotherapy in selected cancers, but data are sparse in the context of TNBC. This review provides an overview of recent progress in the application of OVs as a tool for precision TNBC treatment.

Novel bioengineered drugs with immunotherapies for malignant pleural effusion: Remodulate tumor immune microenvironment and activate immune system

Malignant pleural effusion (MPE) remains a clinical issue since it is associated with advanced-stage cancers and dismal survival, with immunosuppressive tumor microenvironment (TME) and ineffective drug delivery. Conventional therapies such as thoracentesis and pleurodesis are for symptom relief but palliative, without inducing immunity and prolonging survival. Emerging new bioengineered drugs, synergizing with immunotherapies, offer a new paradigm by dual-targeting TME remodeling and immune activation. These technologies leverage nanotechnology, gene editing, and biomaterials to offer precise spatiotemporal control. This review illustrates the molecular mechanism of the immunosuppressive TME in MPE. It examines the newest bioengineering platforms-such as cytokine-encapsulated nanoparticles and oncolytic viruses-that can reactivate immune mechanisms. We highlight preclinical and clinical evidence of the effectiveness of combinatorial strategies in overcoming local immune tolerance and potential risks in adverse events. While the clinical transformation challenge remains, future directions necessitate cross-disciplinary convergence to engineer intelligent delivery vehicles and predictive biomarkers for patient stratification. By integrating immunotherapy with bioengineering, this strategy not only restores antitumor immunity but also portends a new epoch of precision medicine for MPE.

Combination therapy with oncolytic viruses for lung cancer treatment

Lung cancer is the leading cause of cancer-related death globally. Despite various treatment options, adverse reactions and treatment resistance limit their clinical application and efficacy, therefore, new effective treatment options are still needed. Oncolytic viruses (OVs) are a new anti-cancer option. With a powerful anti-tumor effect, OVs are gradually being applied to the treatment of solid tumor. In clinical practice, we have found that in patients with NSCLC and SCLC, OVs combined with immune checkpoint inhibitors (ICI) treatment make tumor with poor response to immunotherapy become sensitive. Furthermore, studies have shown that OVs combined with chemotherapy, radiation therapy, and other immune approaches (such as anti-pd1 drugs) have synergistic effects. These studies suggest that OVs combined therapy may bring hope for the treatment of lung cancer patients. This article will review the current status and prospect of OVs combination therapy in the field of lung cancer treatment and summarizes the mechanism of action.

Understanding the interplay between oHSV and the host immune system: Implications for therapeutic oncolytic virus development

Oncolytic herpes simplex viruses (oHSV) preferentially replicate in cancer cells while inducing antitumor immunity, and thus, they are often referred to as in situ cancer vaccines. OHSV infection of tumors elicits diverse host immune responses comprising both innate and adaptive components. Although the innate and adaptive immune responses primarily target the tumor, they also contribute to antiviral immunity, limiting viral replication/oncolysis. OHSV-encoded proteins use various mechanisms to evade host antiviral pathways and immune recognition, favoring oHSV replication, oncolysis, and spread. In general, oHSV infection and replication within tumors results in a series of sequential events, such as oncolysis and release of tumor and viral antigens, dendritic cell-mediated antigen presentation, T cell priming and activation, T cell trafficking and infiltration to tumors, and T cell recognition of cancer cells, leading to tumor (and viral) clearance. These sequential events align with all steps of the cancer-immunity cycle. However, a comprehensive understanding of the interplay between oHSV and host immune responses is crucial to optimize oHSV-induced antitumor immunity and efficacy. Therefore, this review aims to elucidate oHSV's communication with innate and adaptive immune systems and use such interactions to improve oHSV's potential as a potent immunovirotherapeutic agent against cancer.

Talimogene laherparepvec (T-VEC) as a treatment for melanoma: A systematic review

Background and aimsMelanoma now presents an average risk of 1 in 50 in the Western world. Talimogene laherparepvec (T-VEC), an FDAapproved oncolytic virus derived from Herpes Simplex Virus type 1 (HSV-1), has proven effective in reducing morbidity and mortality from melanoma but causes adverse effects like chills, fever, exhaustion, and injection site discomfort. Research focuses on combining T-VEC with immune checkpoint inhibitors, such as pembrolizumab, to enhance its efficacy and broaden its application.MethodsA systematic search was conducted using PubMed, Scopus, Web of Science, Google Scholar, and ProMED, adhering to PRISMA guidelines. Results were tabulated and analyzed.ResultsThis review included 15 studies comprising nine cohorts, four case reports, a case series, and a randomized control trial, involving 779 melanoma patients in stages IIIB to IV, 58% of whom were male with a mean age of 65 years. Treatment duration with T-VEC averaged 35.07 weeks, with dosages ranging from 10^6 to 10^8 PFU/ml. The intervention yielded a mean DRR of 41.87% and an ORR of 62.2%. The most common side effect was chills, affecting 21.69% of participants. Pyrexia was reported by 20.41% of participants, followed by influenzalike illness (14.89%).ConclusionT-VEC effectively improves ORR and DRR in melanoma patients. However, further research is needed on combination therapy prospects and its adverse effects.

Oncolytic Virus Infection Modulates Lysine Acetyltransferase in Gliomas: Comprehensive Analysis and Experimental Validation of KAT8 in Glioma

Oncolytic virotherapy, which uses engineered viruses to selectively target tumour cells, has emerged as a potential treatment in glioma. However, how oncolytic virus infection modulates lactylation enzymes in gliomas remains unclear. The RNA-seq data after oncolytic virus EV-A71 infection on glioma cells was analysed to screen and lysine acetyltransferase 8 (KAT8) was selected. We analysed KAT8 expression in glioma tissues using data from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases. Associations between KAT8 expression and clinicopathological features were evaluated. Kaplan-Meier survival analysis and Cox regression models were used to assess the prognostic value of KAT8. Functional annotation analyses were performed to explore the KAT8-related biological processes. Single-cell RNA-sequencing data were analysed to investigate cell-type-specific KAT8 expression. In vitro experiments were conducted to validate the effects of KAT8 knockdown on apoptosis in glioma cells. KAT8 was among the top 5 down-regulated genes in glioma cells after oncolytic viruses EV-A71 infection. KAT8 was significantly overexpressed in glioma tissues compared to normal brain tissues, with higher expression in lower-grade gliomas. High KAT8 expression was associated with 1p19q co-deletion, IDH mutation, and younger patient age. Notably, high KAT8 expression correlated with better overall survival in grade IV gliomas. Functional analyses revealed KAT8's involvement in neuronal development, mRNA processing, and apoptosis regulation. Single-cell sequencing data revealed a negative correlation between KAT8 expression and apoptosis in glioblastoma cells. In vitro experiments confirmed the increased apoptosis in glioma cell lines following KAT8 knockdown. Our findings suggest that the regulatory pathway of oncolytic virus infection for lactylation enzymes may be a key pathway affecting gliomas. These findings highlight KAT8 as a potential prognostic biomarker and therapeutic target for gliomas.

Immune checkpoint blockade for cancer therapy: current progress and perspectives

Dysfunction of anti-tumor immune responses is crucial for cancer progression. Immune checkpoint blockade (ICB), which can potentiate T cell responses, is an effective strategy for the normalization of host anti-tumor immunity. In recent years, immune checkpoints, expressed on both tumor cells and immune cells, have been identified; some of them have exhibited potential druggability and have been approved by the US Food and Drug Administration (FDA) for clinical treatment. However, limited responses and immune-related adverse events (irAEs) cannot be ignored. This review outlines the development and applications of ICBs, potential strategies for overcoming resistance, and future directions for ICB-based cancer immunotherapy.

IP6K2 mutations as a novel mechanism of resistance to oncolytic virus therapy

BACKGROUND

Oncolytic virus therapy (OVT) represents a promising frontier in cancer treatment. Despite its efficacy in clinical trials, variability in patient response, particularly resistance development, highlights the need for tailored therapeutic strategies.

METHODS

The Inositol Hexakisphosphate Kinase 2 (IP6K2) gene knock out was carried by CRISPR/Cas9 system. The evaluation of biomarkers of apoptosis and relevant pathways was conducted to be assessed. Attachment assay was conducted to verify the binding ability of virus to the host cells. Cell proliferation and apoptosis was assessed. Subcutaneous xenograft model was used to evaluate IP6K2 knock out influence in vivo. cBioPortal and TCGA database were applied to analyze genomic alterations in pan-cancer.

RESULTS

IP6K2 was essential for effective Herpes Simplex Virus Type1 (HSV-1) replication and subsequent cell apoptosis, acting through the tumor Protein p53 (p53) and Cyclin-Dependent Kinase Inhibitor 1 A (p21) signaling axis. The tumor model demonstrated that tumors lacking IP6K2 exhibited resistance to HSV-1 oncolysis, resulting in diminished therapeutic outcomes. Analysis of cBioPortal and TCGA databases corroborated the potential resistance stemming from IP6K2 mutations across various cancer types, underscoring the necessity for pre-treatment IP6K2 status assessment.

CONCLUSIONS

This study underscores the role of IP6K2 as potential markers of resistance, which opens avenues for precision medicine approaches in OVT.

Killing the killers: Natural killer cell therapy targeting glioma stem cells in high-grade glioma

High-grade gliomas (HGGs), including glioblastoma (GBM) in adults and diffuse intrinsic pontine glioma (DIPG) in children, are among the most aggressive and deadly brain tumors. A key factor in their resilience is the presence of glioma stem cells (GSCs), which drive tumor initiation, progression, and resistance to treatment. Targeting and eradicating GSCs holds potential for curing both GBM and DIPG. Natural killer (NK) cells, as part of the innate immune system, naturally recognize and destroy malignant cells. Recent advances in NK cell-based therapies, such as chimeric antigen receptor (CAR)-NK cells, NK cell engagers, and NK cell-derived exosomes, offer promising approaches for treating GBM and DIPG, particularly by addressing the persistence of GSCs. This review highlights these advancements, explores challenges such as the blood-brain barrier and the immunosuppressive tumor microenvironment, and proposes future directions for improving and clinically advancing these NK cell-based therapies for HGGs.

Strategies to Overcome Antigen Heterogeneity in CAR-T Cell Therapy

Chimeric antigen receptor (CAR) gene-modified T-cell therapy has achieved significant success in the treatment of hematological malignancies. However, this therapy has not yet made breakthroughs in the treatment of solid tumors and still faces issues of resistance and relapse in hematological cancers. A major reason for these problems is the antigenic heterogeneity of tumor tissues. This review outlines the antigenic heterogeneity encountered in CAR-T cell therapy and the corresponding strategies to address it. These strategies include using combination therapy to increase the abundance of target antigens, optimizing the structure of CARs to enhance sensitivity to low-density antigens, developing multi-targeted CAR-T cells, and reprogramming the TME to activate endogenous immunity. These approaches offer new directions for overcoming tumor antigenic heterogeneity in CAR-T cell therapy.

Cancer vaccines: current status and future directions

Cancer continues to be a major global health burden, with high morbidity and mortality. Building on the success of immune checkpoint inhibitors and adoptive cellular therapy, cancer vaccines have garnered significant interest, but their clinical success remains modest. Benefiting from advancements in technology, many meticulously designed cancer vaccines have shown promise, warranting further investigations to reach their full potential. Cancer vaccines hold unique benefits, particularly for patients resistant to other therapies, and they offer the ability to initiate broad and durable T cell responses. In this review, we highlight the antigen selection for cancer vaccines, introduce the immune responses induced by vaccines, and propose strategies to enhance vaccine immunogenicity. Furthermore, we summarize key features and notable clinical advances of various vaccine platforms. Lastly, we delve into the mechanisms of tumor resistance and explore the potential benefits of combining cancer vaccines with standard treatments and other immunomodulatory approaches to improve vaccine efficacy.

Synergistic strategies for glioblastoma treatment: CRISPR-based multigene editing combined with immune checkpoint blockade

Glioblastoma (GBM) is a primary brain tumor known for its high levels of aggressiveness and resistance to current treatments such as radiotherapy and chemotherapy. As a result, there is a pressing need for innovative therapeutic approaches to combat GBM. Thus, we have developed an engineered multifunctional extracellular vesicle (EV) delivery system that offers an "all-in-one" strategy for GBM therapy. Our approach involved the use of genetic engineering to the long-lasting production of PD-1 and the brain-specific peptide angiopep-2 on the surface of EVs. These modified EVs were then utilized to rejuvenate exhausted CD8+ T cells blocking PD-L1, resulting in significant therapeutic benefits for GBM treatment. Furthermore, the EVs contained Cas9 protein and sgRNA for precise and minimally invasive gene therapy, which addressing the key barriers associated with in vivo CRISPR‒Cas9 gene editing treatment. The multigene editing of EVs resulted in efficient intratumor multisite gene editing (PLK1: 58.6%, VEGF: 52.7%), leading to the successful apoptosis of tumor cells in vivo and demonstrating an antiangiogenic effect. This research introduces a promising universal platform for combining immune checkpoint blockade therapy with gene editing treatment.

Advances in preclinical and clinical studies of oncolytic virus combination therapy

Oncolytic viruses represent a distinct class of viruses that selectively infect and destroy tumor cells while sparing normal cells. Despite their potential, oncolytic viruses encounter several challenges as standalone therapies. Consequently, the combination of oncolytic viruses with other therapeutic modalities has emerged as a prominent research focus. This paper summarizes the tumor-killing mechanisms of oncolytic viruses, explores their integration with radiotherapy, chemotherapy, immune checkpoint inhibitors, CAR-T, and CAR-NK therapies, and provides an overview of related clinical trials. By synthesizing these advancements, this study seeks to offer valuable insights for the clinical translation of oncolytic virus combination therapies.

Single-cell data-driven design of armed oncolytic virus to boost cooperative innate-adaptive immunity against cancer

Oncolytic viruses have been considered promising cancer immunotherapies. However, oncovirotherapy agents impart durable responses in only a subset of cancer patients. Thus, exploring the cellular and molecular mechanisms underlying the heterogeneous responses in patients can provide guidance to develop more effective oncolytic virus therapies. Single-cell RNA sequencing (scRNA-seq) analysis of tumors responsive and non-responsive to oncovirotherapy revealed signatures of the tumor immune microenvironment associated with immune response. Thus, we designed and constructed an armed oncolytic virus, OV-5A, that expressed five genes with non-redundant functions. OV-5A treatment exhibits robust immune response against various tumors in multiple mouse models, peripheral blood mononuclear cell -patient-derived xenograft models, organoid-immune cell co-culture systems, and patient tissue sections by activating a cooperative innate-adaptive immune response against tumor cells. scRNA-seq analysis of complete responders and partial responders to OV-5A treatment guided the design of combination therapy of OV-5A. This data-driven approach paves an innovative way to rationalize the design of oncolytic virus and multi-agent combination therapies.

Oncolytic Viruses in Ovarian Cancer: Where Do We Stand? A Narrative Review

Ovarian cancer (OC) remains the most lethal gynecologic malignancy with limited effective treatment options. Oncolytic viruses (OVs) have emerged as a promising therapeutic approach for cancer treatment, capable of selectively infecting and lysing cancer cells while stimulating anti-tumor immune responses. Preclinical studies have demonstrated significant tumor regression and prolonged survival in OC models using various OVs, such as herpes simplex. Early-phase clinical trials have shown a favorable safety profile, though the impact on patient survival has been modest. Current research focuses on combining OVs with other treatments like immune checkpoint inhibitors to enhance their efficacy. We provide a comprehensive overview of the current understanding and future directions for utilizing OVs in the management of OC.

Emerging advances in drug delivery systems (DDSs) for optimizing cancer complications

The management and treatment of tumor complications pose continuous challenges due to the inherent complexity. However, the advent of drug delivery systems (DDSs) brings promising opportunities to address the tumor complications using innovative technological approaches. This review focuses on common oncological complications, including cancer thrombosis, malignant serous effusion, tumor-associated infections, cancer pain, and treatment-related complications. Emphasis was placed on the application and potential of DDSs in mitigating and treating these tumor complications, and we delved into the underlying mechanisms of common cancer-associated complications, discussed the limitations of conventional treatments, and outlined the current status and potential development of DDSs for various complications in this review. Moreover, we have discussed the existing challenges in DDSs research, underscoring the need for addressing issues related to biocompatibility and targeting of DDSs, optimizing drug delivery routes, and enhancing delivery efficiency and precision. In conclusion, DDSs offer promising avenues for treating cancer complications, offering the potential for the development of more effective and safer drug delivery strategies, thereby improving the quality of life and survival rates of cancer patients.

Oncolytic reprogramming of tumor microenvironment shapes CD4 T-cell memory via the IL6ra-Bcl6 axis for targeted control of glioblastoma

Oncolytic viruses (OVs) emerge as a promising cancer immunotherapy. However, the temporal impact on tumor cells and the tumor microenvironment, and the nature of anti-tumor immunity post-therapy remain largely unclear. Here we report that CD4+ T cells are required for durable tumor control in syngeneic murine models of glioblastoma multiforme after treatment with an oncolytic herpes simplex virus (oHSV) engineered to express IL-12. The upregulated MHCII on residual tumor cells facilitates programmed polyfunctional CD4+ T cells for tumor control and for recall responses. Mechanistically, the proper ratio of Bcl-6 to T-bet in CD4+ T cells navigates their enhanced anti-tumor capacity, and a reciprocal IL6ra-Bcl-6 regulatory axis in a memory CD4+ T-cell subset, which requires MHCII signals from reprogrammed tumor cells, tumor-infiltrating and resident myeloid cells, is necessary for the prolonged response. These findings uncover an OV-induced tumor/myeloid-CD4+ T-cell partnership, leading to long-term anti-tumor immune memory, and improved OV therapeutic efficacy.

Mesenchymal Stem Cells Carrying Viral Fusogenic Protein p14 to Treat Solid Tumors by Inducing Cell-Cell Fusion and Immune Activation

Background: Chimeric antigen receptor (CAR)-based immune cell therapies attack neighboring cancer cells after receptor recognition but are unable to directly affect distant tumor cells. This limitation may contribute to their inefficiency in treating solid tumors, given the restricted intratumoral infiltration and immunosuppressive tumor microenvironment. Therefore, cell-cell fusion as a cell-killing mechanism might develop a novel cytotherapy aimed at improving the efficacy against solid tumors. Methods: We constructed a fusogenic protein, fusion-associated small transmembrane (FAST) p14 of reptilian reovirus, into cancer cells and mesenchymal stem cells (MSCs), which cocultured with various colon cancer cells and melenoma cells to validate its ability to induce cell fusion and syncytia formation. RNA sequencing, quantitative reverse transcription polymerase chain reaction, and Western blot were performed to elucidate the mechanism of syncytia death. Cell viability assay was employed to assess the killing effects of MSCs carrying the p14 protein (MSCs-p14), which was also identified in the subcutaneous tumor models. Subsequently, the Tet-On system was introduced to enhance the controllability and safety of therapy. Results: Cancer cells incorporated with fusogenic protein p14 FAST from reovirus fused together to form syncytia and subsequently died through apoptosis and pyroptosis. MSCs-p14 cocultured with different cancer cells and effienctly induced cancer cell fusion and caused widespread cancer cell death in vitro. In mouse tumor models, mMSCs-p14 treatment markedly suppressed tumor growth and also enhanced the activity of natural killer cells and macrophages. Controllability and safety of MSCs-p14 therapy were further improved by introducing the tetracycline-controlled transcriptional system. Conclusion: MSC-based cytotherapy carrying viral fusogenic protein in this study kills cancer cells by inducing cell-cell fusion. It has demonstrated definite efficacy in treating solid tumors and is worth considering for clinical development.

Advances in Radionuclide-Labeled Biological Carriers for Tumor Imaging and Treatment

Biological carriers have emerged as significant tools to deliver radionuclides in nuclear medicine, providing a meaningful perspective for tumor imaging and treatment. Various radionuclide-labeled biological carriers have been developed to meet the needs of biomedical applications. This review introduces the principles of radionuclide-mediated imaging and therapy and the selected criteria of them, as well as a comprehensive description of the characteristics and functions of representative biological carriers including bacteria, cells, viruses, and their biological derivatives, emphasizing the labeled strategies of biological carriers combined with radionuclides. Subsequently, we in-depth introduce the application of radionuclide-labeled biological carriers in tumor imaging and treatment, including the imaging of the behaviors of biological carriers in vivo and tumor metastasis and the tumor treatment by radionuclide therapy, plus other strategies and radiation-induced photodynamic therapy. Finally, the challenges and prospects of radionuclide-labeled biological carriers are discussed to improve the shortcomings of this innovative platform and promote clinical transformation in the field of medical imaging.

Improving systemic delivery of oncolytic virus by cellular carriers

Oncolytic virotherapy (OVT) is a promising option for cancer treatment. OVT involves selective oncolytic virus (OV) replication within cancer cells, which triggers anti-tumor responses and immunostimulation. Despite promising potential, OVT faces critical challenges, including insufficient tumor-specific targeting, which results in limited tumor penetration and variability in therapeutic efficacy. These challenges are particularly pronounced in solid tumors with complex microenvironments and heterogeneous vascularization. A comprehensive research program is currently underway to develop and refine innovative delivery methods to address these issues to enhance OVT precision and efficacy. A principal area of investigation is the utilization of cellular carriers to enhance the delivery and distribution of OVs within tumor microenvironments, thereby optimizing immune system activation and maximizing anti-tumor effects. This review offers a comprehensive overview of the current strategies that are being used to enhance the delivery of OVs via cellular carriers with the goal of improving the clinical impact of OVT in cancer therapy.

Intratumoral oncolytic virus OH2 injection in patients with locally advanced or metastatic sarcoma: a phase 1/2 trial

BACKGROUND

Intratumoral oncolytic herpes simplex virus 2-GM CSF (OH2) injection has shown safety and antitumor efficacy in patients with solid tumors. Here, we examined the safety and efficacy of OH2 as a single agent or in combination with HX008, an NMPA-approved PD-1 inhibitor, in locally advanced or metastatic sarcoma patients.

METHODS

This multicenter, phase 1/2 trial enrolled patients with injectable sarcoma lesions, who had failed at least 1 or more lines of standard treatment. Patients were treated with OH2 at three dose levels (106, 107 and 108 CCID50/mL) as single agent or in combination with a fixed dose of HX008. The primary endpoints were safety and tolerability in phase 1 and objective response rate determined by RECIST (V.1.1) criteria and immune-RECIST in phase 2.

RESULTS

Between October 20, 2020 and December 30, 2023, 26 patients were enrolled. Seven patients were treated with single-agent OH2 and 19 with HX008 and OH2 combination. No dose-limiting toxicities were observed during the dose escalation. We documented four partial or complete responses in injected lesions, and one partial response in non-injected lesions, which were all from the combination group. Hence, the overall response rate was 0% and 16.7% in the single agent and combination groups, respectively. The duration of response was 3.9-6.5 months. The most frequent treatment-related adverse events (TRAEs) were fever (n=9). Grade 3 or 4 TRAEs were reported in four patients (15.4%). A clear increase in CD8+cell density in the tumor microenvironment was observed in the patients' post-treatment specimens compared with baseline.

CONCLUSIONS

Intratumoral injection of oncolytic virus OH2 is well tolerable in patients with sarcoma. Further investigation of OH2 with HX008 in select sarcoma subtypes is warranted.

Emerging combined CAR-NK cell therapies in cancer treatment: Finding a dancing partner

In recent decades, immunotherapy with chimeric antigen receptors (CARs) has revolutionized cancer treatment and given hope where other cancer therapies have failed. CAR-natural killer (NK) cells are NK cells that have been engineered ex vivo with a CAR on the cell membrane with high specificity for specific target antigens of tumor cells. The impressive results of several studies suggest that CAR-NK cell therapy has significant potential and successful performance in cancer treatment. Despite its effectiveness, CAR-NK cell therapy can have significant challenges when it comes to treating cancer. These challenges include tumor heterogeneity, antigen escape, an immunosuppressive tumor microenvironment, limited tissue migration from blood, exhaustion of CAR-NK cells, and inhibition by immunosuppressive checkpoint molecule signaling, etc. In CAR-T cell therapy, the use of combined approaches has shown encouraging outcomes for tumor regression and improved cancer treatment compared to single therapies. Therefore, to overcome these significant challenges in CAR-NK cells, innovative combination therapies of CAR-NK cells with other conventional therapies (e.g., chemotherapy and radiotherapy) or other immunotherapies are needed to counteract the above challenges and thereby increase the activity of CAR-NK cells. This review comprehensively discusses various cancer-treatment approaches in combination with CAR-NK cell therapy in the hope of providing valuable insights that may improve cancer treatment in the near future.

Nature killer cell for solid tumors: Current obstacles and prospective remedies in NK cell therapy and beyond

In recent years, cell therapy has emerged as an innovative treatment method for the management of clinical tumors following immunotherapy. Among them, Natural killer (NK) cell therapy has achieved a significant breakthrough in the treatment of hematological tumors. However, the therapeutic effectiveness of NK cells in the treatment of solid tumors remains challenging. With the progress of gene editing and culture techniques and their application to NK cell engineering, it is expected that NK cell therapy will revolutionize the treatment of solid tumors. In this review, we explore the discovery and biological properties of NK cells, their role in the tumor microenvironment, and the therapeutic strategies, clinical trials, challenges, and prospects of NK cells in the treatment of solid tumors.

Therapeutic manipulation and bypass of the blood-brain barrier: powerful tools in glioma treatment

The blood-brain barrier (BBB) remains an obstacle for delivery of chemotherapeutic agents to gliomas. High grade and recurrent gliomas continue to portend a poor prognosis. Multiple methods of bypassing or manipulating the BBB have been explored, including hyperosmolar therapy, convection-enhanced delivery (CED), laser-guided interstitial thermal therapy (LITT), and Magnetic Resonance Guided Focused Ultrasound (MRgFUS) to enhance delivery of chemotherapeutic agents to glial neoplasms. Here, we review these techniques, currently ongoing clinical trials to disrupt or bypass the BBB in gliomas, and the results of completed trials.

Focused Ultrasound in Cancer Immunotherapy: A Review of Mechanisms and Applications

Ultrasound is well-perceived for its diagnostic application. Meanwhile, ultrasound, especially focused ultrasound (FUS), has also demonstrated therapeutic capabilities, such as thermal tissue ablation, hyperthermia, and mechanical tissue ablation, making it a viable therapeutic approach for cancer treatment. Cancer immunotherapy is an emerging cancer treatment approach that boosts the immune system to fight cancer, and it has also exhibited enhanced effectiveness in treating previously considered untreatable conditions. Currently, cancer immunotherapy is regarded as one of the four pillars of cancer treatment because it has fewer adverse effects than radiation and chemotherapy. In recent years, the unique capabilities of FUS in ablating tumors, regulating the immune system, and enhancing anti-tumor responses have resulted in a new field of research known as FUS-induced/assisted cancer immunotherapy. In this work, we provide a comprehensive overview of this new research field by introducing the basics of focused ultrasound and cancer immunotherapy and providing the state-of-the-art applications of FUS in cancer immunotherapy: the mechanisms and preclinical and clinical studies. This review aims to offer the scientific community a reliable reference to the exciting field of FUS-induced/assisted cancer immunotherapy, hoping to foster the further development of related technology and expand its medical applications.

Modified Vaccinia Virus Ankara Selectively Targets Human Cancer Cells With Low Expression of the Zinc-Finger Antiviral Protein

Oncolytic viruses are emerging as promising cancer therapeutic agents, with several poxviruses, including vaccinia virus (VACV) and myxoma virus, showing significant potential in preclinical and clinical trials. Modified vaccinia virus Ankara (MVA), a laboratory-derived VACV strain approved by the FDA for mpox and smallpox vaccination, has been shown to be incapable of replicating in human cells unless zinc finger antiviral protein (ZAP) is repressed. Notably, ZAP deficiency is prevalent in various cancer types. We hypothesized that MVA could selectively target and replicate in ZAP-deficient cancer cells. Our study examined MVA's replication across multiple cancer cell lines with varying ZAP expression levels, revealing that MVA replicates more efficiently in cells with lower ZAP expression. Additionally, we assessed MVA's oncolytic potential using a xenograft mouse model, where cancer cells were transplanted into immunodeficient mice. The data demonstrated that MVA significantly reduced tumors with lower ZAP expression without causing morbidity in nude mice. These findings suggest that MVA holds promise for further development as a targeted therapy for ZAP-deficient cancers.

Advancing tumor vaccines: Overcoming TME challenges, delivery strategies, and biomaterial-based vaccine for enhanced immunotherapy

Tumor vaccines, as an immunotherapeutic approach, harness the body's immune cells to provoke antitumor responses, which have shown promising efficacy in clinical settings. However, the immunosuppressive tumor microenvironment (TME) and the ineffective vaccine delivery systems hinder the progression of many vaccines beyond phase II trials. This article begins with a comprehensive review of the complex interactions between tumor vaccines and TME, summarizing the current state of vaccine clinical research. Subsequently, we review recent advancements in targeted vaccine delivery systems and explore biomaterial-based tumor vaccines as a strategy to improve the efficacy of both delivery systems and treatment. Finally, we have presented our perspectives on tumor vaccine development, aiming to advance the field towards the creation of more effective tumor vaccines.

Universal CAR cell therapy: Challenges and expanding applications

Chimeric Antigen Receptor (CAR) T cell therapy has gained success in adoptive cell therapy for hematological malignancies. Although most CAR cell therapies in clinical trials or markets remain autologous, their acceptance has been limited due to issues like lengthy manufacturing, poor cell quality, and demanding cost. Consequently, "Off-the-shelf", universal CAR (UCAR) cell therapy has emerged. Current concerns with UCAR therapies revolve around side effects such as graft versus host disease (GVHD) and host versus graft response (HVGR). Preclinical research on UCAR cell therapies aims to enhance efficacy and minimize these side effects. Common approaches involve gene editing techniques to knock out T cell receptor (TCR), human leukocyte antigen (HLA), and CD52 expression to mitigate GVHD and HVGR risks. However, these methods carry drawbacks including potential genotoxicity of the edited cells. Most recently, novel editing techniques, such as epigenetic editing and RNA writer systems, have been developed to reduce the risk of GVHD and HVGR, allowing for multiplex editing at different sites. Additionally, incorporating more cell types into UCAR cell therapies, like T-cell subtypes (DNT, γδT, virus-specific T cells) and NK cells, can efficiently target tumors without triggering side effects. In addition, the limited efficacy of T cells and NK cells against solid tumors is being addressed through CAR-Macrophages. In summary, CAR cell therapy has evolved to accommodate multiple cell types while expanding applications to various diseases, including hematologic malignancies and solid tumors, which holds tremendous growth potential and is promised to improve the lives of more patients in the future.

Advances in Preventive and Therapeutic Strategies for Oral Cancer: A Short Review

Oral cancer is a major global health concern, with high incidence and mortality rates, especially in high-risk populations. Early diagnosis remains a challenge, and current treatments, such as surgery, radiation, and chemotherapy, have limited effectiveness, particularly in advanced stages. Recent advances in targeted therapies and immunotherapy offer promising alternatives, providing more precise and personalized treatment options. Targeted therapies, such as epidermal growth factor receptor inhibitors, aim to disrupt specific molecular pathways in tumor growth, while immunotherapies, including immune checkpoint inhibitors and chimeric antigen receptor-T cell therapy, enhance the body's immune response to fight cancer. Combination therapies, integrating both targeted and immune strategies, are being explored to overcome the limitations of single-agent treatments. This review highlights the current strategies in the prevention and treatment of oral cancer, discusses emerging therapies, explores future research directions, focusing on optimizing existing treatments, identifying new biomarkers, and developing innovative therapeutic approaches. The potential of personalized medicine and combination therapies offers new hope for improving survival rates and quality of life for oral cancer patients.

AVL-armed oncolytic vaccinia virus promotes viral replication and boosts antitumor immunity via increasing ROS levels in pancreatic cancer

Pancreatic malignant neoplasm is an extremely deadly malignancy well known for its resistance to traditional therapeutic approaches. Enhanced treatments are imperative for individuals diagnosed with pancreatic cancer (PC). Recent investigations have shed light on the wide-ranging anticancer properties of genetic therapy facilitated by oncolytic vaccinia virus. To illuminate the precise impacts of Aphrocallistes vastus lectin-armed oncolytic vaccinia virus (oncoVV-AVL) on PC, AsPC-1 and PANC-1 cells underwent treatment with oncoVV-AVL. Our findings revealed that oncoVV-AVL possesses the capacity to heighten oncolytic effects on PC cells and incite the production of diverse cytokines like tumor necrosis factor-α, interleukin-6 (IL-6), IL-8, and interferon-I (IFN-I), without triggering antiviral responses. Additionally, oncoVV-AVL can significantly elevate the levels of ROS in PC cells, initiating an oxidative stress response that promotes viral replication, apoptosis, and autophagy. Moreover, in xenograft tumor models, oncoVV-AVL notably restrained PC growth, enhanced IFN-γ levels in the bloodstream, and reprogrammed macrophages. Our investigation indicates that oncoVV-AVL boosts the efficacy of antitumor actions against PC tumors by orchestrating reactive oxygen species-triggered viral replication, fostering M1 polarization, and reshaping the tumor microenvironment to transform cold PC tumors into hot ones. These findings imply that oncoVV-AVL could present a novel therapeutic approach for treating PC tumors.

Virus replication is not required for oncolytic bovine herpesvirus-1 immunotherapy

Oncolytic viruses are a promising approach for cancer treatment where viruses selectively target and kill cancer cells while also stimulating an immune response. Among viruses with this ability, bovine herpesvirus-1 (BoHV-1) has several advantages, including observations suggesting it may not require viral replication for its anti-cancer effects. We previously demonstrated that binding and penetration of enveloped virus particles are sufficient to trigger intrinsic and innate immune signaling in normal cells, while other groups have published the efficacy of non-replicating viruses as viable immunotherapies in different cancer models. In this work, we definitively show that live and UV-inactivated (UV) (non-replicating) BoHV-1-based regimens extend survival of tumor-bearing mice to similar degrees and induce infiltration of similar immune cell populations, with the exception of neutrophils. Transcriptomic analysis of tumors treated with either live or UV BoHV-1-based regimens revealed similar pathway enrichment and a subset of overlapping differentially regulated genes, suggesting live and UV BoHV-1 have similar mechanisms of activity. Last, we present a gene signature across our in vitro and in vivo models that could potentially be used to validate new BoHV-1 therapeutics. This work contributes to the growing body of literature showing that replication may not be necessary for therapeutic efficacy of viral immunotherapies.

Current Advances in Viral Nanoparticles for Biomedicine

Viral nanoparticles (VNPs) have emerged as crucial tools in the field of biomedicine. Leveraging their biological and physicochemical properties, VNPs exhibit significant advantages in the prevention, diagnosis, and treatment of human diseases. Through techniques such as chemical bioconjugation, infusion, genetic engineering, and encapsulation, these VNPs have been endowed with multifunctional capabilities, including the display of functional peptides or proteins, encapsulation of therapeutic drugs or inorganic particles, integration with imaging agents, and conjugation with bioactive molecules. This review provides an in-depth analysis of VNPs in biomedicine, elucidating their diverse types, distinctive features, production methods, and complex design principles behind multifunctional VNPs. It highlights recent innovative research and various applications, covering their roles in imaging, drug delivery, therapeutics, gene delivery, vaccines, immunotherapy, and tissue regeneration. Additionally, the review provides an assessment of their safety and biocompatibility and discusses challenges and future opportunities in the field, underscoring the vast potential and evolving nature of VNP research.

Mitochondrial metabolic reprogramming of macrophages and T cells enhances CD47 antibody-engineered oncolytic virus antitumor immunity

BACKGROUND

Although immunotherapy can reinvigorate immune cells to clear tumors, the response rates are poor in some patients. Here, CD47 antibody-engineered oncolytic viruses (oAd-αCD47) were employed to lyse tumors and activate immunity. The oAd-αCD47 induced comprehensive remodeling of the tumor microenvironment (TME). However, whether the acidic TME affects the antitumor immunotherapeutic effects of oncolytic viruses-αCD47 has not been clarified.

METHODS

To assess the impact of oAd-αCD47 treatment on the TME, we employed multicolor flow cytometry. Glucose uptake was quantified using 2NBDG, while mitochondrial content was evaluated with MitoTracker FM dye. pH imaging of tumors was performed using the pH-sensitive fluorophore SNARF-4F. Moreover, changes in the calmodulin-dependent protein kinase II (CaMKII)/cyclic AMP activates-responsive element-binding proteins (CREB) and peroxisome proliferator-activated receptor gamma coactivator-1α (PGC1α) signaling pathway were confirmed through western blotting and flow cytometry.

RESULTS

Here, we identified sodium bicarbonate (NaBi) as the potent metabolic reprogramming agent that enhanced antitumor responses in the acidic TME. The combination of NaBi and oAd-αCD47 therapy significantly inhibited tumor growth and produced complete immune control in various tumor-bearing mouse models. Mechanistically, combination therapy mainly reduced the number of regulatory T cells and enriched the ratio of M1-type macrophages TAMs (M1.TAMs) to M2-type macrophages TAMs (M2.TAMs), while decreasing the abundance of PD-1+TIM3+ expression and increasing the expression of CD107a in the CD8+ T cells. Furthermore, the combination therapy enhanced the metabolic function of T cells and macrophages by upregulating PGC1α, a key regulator of mitochondrial biogenesis. This metabolic improvement contributed to a robust antitumor response. Notably, the combination therapy also promoted the generation of memory T cells, suggesting its potential as an effective neoadjuvant treatment for preventing postoperative tumor recurrence and metastasis.

CONCLUSIONS

Tumor acidic microenvironment impairs mitochondrial energy metabolism in macrophages and T cells inducing oAd-αCD47 immunotherapeutic resistance. NaBi improves the acidity of the TME and activates the CaMKII/CREB/PGC1α mitochondrial biosynthesis signaling pathway, which reprograms the energy metabolism of macrophages and T cells in the TME, and oral NaBi enhances the antitumor effect of oAd-αCD47.

Oncolytic vaccinia virus armed with 4-1BBL elicits potent and safe antitumor immunity and enhances the therapeutic efficiency of PD-1/PD-L1 blockade in a pancreatic cancer model

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease with a poor prognosis. Mono-immunotherapy, such as blockade of the PD-1/PD-L1 pathway, for PDAC has proven to be less effective. The systemic exertion of 4-1BB signaling enhanced antitumor immunity accompanied by hepatotoxicity, which is an obstacle for its clinical application. Our study exploits an oncolytic virus armed with 4-1BBL (VV-ΔTK-4L) to locally express 4-1BBL in the tumor microenvironment (TME), thus avoiding hepatotoxicity. VV-ΔTK-4L prolonged the survival time of a pancreatic tumor mouse model and modified the immune status of the TME and spleen. In the TME, the quantities of CD45+ cells, NK1.1+ cells, CD11c+ DCs, CD3+T, CD4+T, and CD8+T cells increased. Compared to VV-ΔTK treatment, VV-ΔTK-4L further increases the number of CD8+T cells with effector phenotypes, and downregulates exhaustion-related molecules on CD8+T cells, and does not increase the proportion of Foxp3+T cells. Thus, the TME of pancreatic cancer was converted from "cold" to "hot" by VV-ΔTK-4L. Blockade of the PD-1/PD-L1 pathway combined with VV-ΔTK-4L further significantly improves the survival ratio of a tumor-bearing mouse model. This study provides a systemic therapeutic strategy and approach for PDAC immunotherapy.

Tumor cell membrane-based vaccines: A potential boost for cancer immunotherapy

Because therapeutic cancer vaccines can, in theory, eliminate tumor cells specifically with relatively low toxicity, they have long been considered for application in repressing cancer progression. Traditional cancer vaccines containing a single or a few discrete tumor epitopes have failed in the clinic, possibly due to challenges in epitope selection, target downregulation, cancer cell heterogeneity, tumor microenvironment immunosuppression, or a lack of vaccine immunogenicity. Whole cancer cell or cancer membrane vaccines, which provide a rich source of antigens, are emerging as viable alternatives. Autologous and allogenic cellular cancer vaccines have been evaluated as clinical treatments. Tumor cell membranes (TCMs) are an intriguing antigen source, as they provide membrane-accessible targets and, at the same time, serve as integrated carriers of vaccine adjuvants and other therapeutic agents. This review provides a summary of the properties and technologies for TCM cancer vaccines. Characteristics, categories, mechanisms, and preparation methods are discussed, as are the demonstrable additional benefits derived from combining TCM vaccines with chemotherapy, sonodynamic therapy, phototherapy, and oncolytic viruses. Further research in chemistry, biomedicine, cancer immunology, and bioinformatics to address current drawbacks could facilitate the clinical adoption of TCM vaccines.

A comprehensive neuroimaging review of the primary and metastatic brain tumors treated with immunotherapy: current status, and the application of advanced imaging approaches and artificial intelligence

Cancer immunotherapy has emerged as a novel clinical therapeutic option for a variety of solid tumors over the past decades. The application of immunotherapy in primary and metastatic brain tumors continues to grow despite limitations due to the physiological characteristics of the immune system within the central nervous system (CNS) and distinct pathological barriers of malignant brain tumors. The post-immunotherapy treatment imaging is more complex. In this review, we summarize the clinical application of immunotherapies in solid tumors beyond the CNS. We provide an overview of current immunotherapies used in brain tumors, including immune checkpoint inhibitors (ICIs), oncolytic viruses, vaccines, and CAR T-cell therapies. We focus on the imaging criteria for the assessment of treatment response to immunotherapy, and post-immunotherapy treatment imaging patterns. We discuss advanced imaging techniques in the evaluation of treatment response to immunotherapy in brain tumors. The imaging characteristics of immunotherapy treatment-related complications in CNS are described. Lastly, future imaging challenges in this field are explored.