Search Results (1,342)

Background/Objectives: Leukemia is associated with high recurrence rates and cancer vaccines are emerging as a promising immunotherapy against the disease. Here, we investigate the mechanism of action by which a personalized vaccine made from leukemia cells infected with an oncolytic virus (ICV) induces anti-tumor immunity. Methods: Using the L1210 murine model, leukemia cells were infected and irradiated to create the ICV. The CRISPR-Cas9 system was used to engineer knockout cells to test in treatment efficacy studies. Results: We found that pro-inflammatory interferons (IFNs) that are produced by infected vaccine cells induce the immunoproteasome (ImP), a specialized proteasome subtype that is found in immune cells. Interestingly, we show that while a vaccine using the oncolytic vesicular stomatitis virus (oVSV) completely protects against tumor challenge, the wild-type (wt) virus, which does not induce the ImP, is not as effective. To delineate the contribution of the ImP for vaccine efficacy, we generated ImP-knockout cell lines and found no differences in treatment efficacy compared to wild-type cells. Furthermore, an ICV using another murine leukemia model that expresses the ImP only when infected by an IFN gamma-encoding variant of the virus demonstrated similar efficacy as the parental virus. Conclusions: Taken together, our data show that ImP expression by vaccine cells was not required for the efficacy of leukemia ICVs. Full article

Glioblastoma (GBM) remains one of the most aggressive and treatment-resistant brain tumors, largely due to its profound intratumoral heterogeneity and immunosuppressive microenvironment. Various classifications of GBM subtypes were created based on transcriptional and methylation profiles. This effort, followed by the development of new technology such as single-nuclei sequencing (snRNAseq) and spatial transcriptomics, led to a better understanding of the glioma cells’ plasticity and their ability to transition between diverse cellular states. GBM cells can mimic neurodevelopmental programs to resemble oligodendrocyte or neural progenitor behavior and hitchhike the local neuronal network to support their growth. The tumor microenvironment, especially under hypoxic conditions, drives the tumor cell clonal selection, which then reshapes the immune cells’ functions. These adaptations contribute to immune evasion by progressively disabling T cell and myeloid cell functions, ultimately establishing a highly immunosuppressive tumor milieu. This complex and metabolically constrained environment poses a major barrier to effective antitumor immunity and limits the success of conventional therapies. Understanding the dynamic interactions between glioma cells and their microenvironment is essential for the development of more effective immunotherapies and rational combination strategies aimed at overcoming resistance and improving patient outcomes. Full article

Myxoma virus (MYXV), a rabbit-specific poxvirus and non-pathogenic in humans and mice, is an excellent candidate oncolytic virus for cancer therapy. MYXV also has immunotherapeutic benefits. In ovarian cancer (OC), immunosuppressive tumor-associated macrophages (TAMs) are key to inhibiting antitumor immunity while hindering therapeutic benefit by chemotherapy and dendritic cell (DC) vaccine. Because MYXV favors binding/entry of macrophages/monocytes, we examined the therapeutic potential of MYXV against TAMs. We found previously that a replication-defective MYXV with targeted deletion of an essential gene, M062R, designated ΔM062R MYXV, activated both the host DNA sensing pathway and the SAMD9 pathway. Treatment with ΔM062R confers therapeutic benefit comparable to that of wild-type replicating MYXV in preclinical models. Here we found that ΔM062R MYXV, when integrated with cisplatin and DC immunotherapy, further improved treatment benefit, likely through promoting tumor antigen-specific T cell function. Moreover, we also tested ΔM062R MYXV in targeting human immunosuppressive TAMs from OC patient ascites in a co-culture system. We found that ΔM062R treatment subverted the immunosuppressive properties of TAMs and elevated the avidity of cytokine production in tumor antigen-specific CD4⁺ T cells. Overall, ΔM062R presents a promising immunotherapeutic platform as a beneficial adjuvant to chemotherapy and DC vaccine. Full article

T-cells constitute an essential component of the adaptive immune response, mount a protective response against foreign pathogens and are important regulators of anti-tumor immunotherapy. In this context, the activation of T-cells and chimeric antigen receptor (CAR)-expressing T-cells is orchestrated by various signaling pathways, involving the initiation of a protein tyrosine phosphorylation cascade. For T-cells, this involves initiation of the phosphorylation cascade via src-related protein-tyrosine kinase p56^lck, which we show to associate with the co-receptors CD4 and CD8 for the induction of a phosphorylation cascade needed for the activation of T-cells. Likewise, p56^lck phosphorylation of the antigen receptor immunoreceptor tyrosine-based activation motifs (ITAMs) and key CD28 tyrosine motifs ensures the functionality and the survival of CARs, while their phospho-targets are also inhibited by PD-1, a key component of the immune checkpoint blockade. This review covers historic and current elements of our knowledge of CD4/CD8–p56^lck-induced activation events and their importance to the development of CAR T-cell immunotherapies. Full article

Cancer is no longer considered as an isolated event. Rather, it occurs because of a complex biological drive orchestrating different cell types, growth factors, cytokines, and signaling pathways within the tumor microenvironment (TME). Cancer-associated fibroblasts (CAFs) are the most populous stromal cells within the complex ecosystem of TME, with significant heterogeneity and plasticity in origin and functional phenotypes. Very enigmatic cells, CAFs determine the progress and outcomes of tumors through extensive reciprocal signaling with different tumors infiltrating immune cells in the TME. In their biological drive, CAFs release numerous chemical mediators and utilize various signaling pathways to recruit and modulate tumor-infiltrating immune cells. The CAF-induced secretome and exosomes render immune cells ineffective for their antitumor activities. Moreover, by upregulating immune inhibitory checkpoints, CAFs create an immunosuppressive TME that impedes the susceptibility of tumor cells to tumor-infiltrating lymphocytes (TILs). Further, by depositing and remodeling extracellular matrix (ECM), CAFs reshape the TME, which enhances tumor growth, invasion, metastasis, and chemoresistance. Understanding of CAF biology and its crosstalk with tumor-infiltrating immune cells is crucial not only to gain insight in tumorigenesis but to optimize the potential of novel targeted immunotherapies for cancers. The complex relationships between CAFs and tumor-infiltrating immune cells remain unclear and need further study. Herein, in this narrative review we have focused on updates of CAF biology and its interactions with tumor-infiltrating immune cells in generating immunosuppressive TME and resistance to cell death. Full article

Recent breakthroughs in cancer immunotherapy have shown remarkable success, yet treatment efficacy varies significantly among individuals. Emerging evidence highlights the gut microbiota as a key modulator of immunotherapy response, while vitamin D (VD), an immunomodulatory hormone, has garnered increasing attention for its potential interactions with gut microbiota and immunotherapy outcomes. However, the precise mechanisms and clinical applications of VD in this context remain controversial. This study systematically analyzed peer-reviewed evidence from PubMed, Scopus, Web of Science, PsycINFO, and MEDLINE (January 2000–May 2025) to investigate the complex interplay among VD, gut microbiota, and cancer immunotherapy. This review demonstrates that VD exerts dual immunomodulatory effects by directly activating immune cells through vitamin D receptor (VDR) signaling while simultaneously reshaping gut microbial composition to enhance antitumor immunity. Clinical data reveal paradoxical outcomes: optimal VD levels correlate with improved immunotherapy responses and reduced toxicity in some studies yet are associated with immunosuppression and poorer survival in others. The bidirectional VD–microbiota interaction further complicates this relationship: VD supplementation enriches beneficial bacteria, which reciprocally regulate VD metabolism and amplify immune responses, whereas excessive VD intake may disrupt this balance, leading to dysbiosis and compromised therapeutic efficacy. These findings underscore the need to elucidate VD’s dose-dependent and microbiota-mediated mechanisms to optimize its clinical application in immunotherapy regimens. Future research should prioritize mechanistic studies of VD’s immunoregulatory pathways, personalized strategies accounting for host–microbiota variability, and large-scale clinical trials to validate VD’s role as an adjuvant in precision immunotherapy. Full article

Tumor immunotherapy has revolutionized cancer treatment by harnessing the immune system to recognize and eliminate malignant cells, with immune checkpoint inhibitors targeting programmed death receptor 1 (PD-1), programmed death-ligand 1 (PD-L1), and cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) demonstrating remarkable clinical success. However, challenges such as treatment resistance, immune-related adverse effects, and high costs highlight the need for novel therapeutic approaches. Aptamers, short, single-stranded oligonucleotides with high specificity and affinity for target molecules, have emerged as promising alternatives to conventional antibody-based therapies. This review provides a comprehensive analysis of aptamer-based strategies targeting immune checkpoints, with a particular focus on PD-1/PD-L1 and CTLA-4. We summarize recent advances in aptamer design, including bispecific and multifunctional aptamers, and explore their potential in overcoming immune resistance and improving therapeutic efficacy. Additionally, we discuss strategies to enhance aptamer stability, bioavailability, and tumor penetration through chemical modifications and nanoparticle conjugation. Preclinical and early clinical studies have demonstrated that aptamers can effectively block immune checkpoint pathways, restore T-cell activity, and synergize with other immunotherapeutic agents to achieve superior anti-tumor responses. By systematically reviewing the current research landscape and identifying key challenges, this review aims to provide valuable insights into the future directions of aptamer-based cancer immunotherapy, paving the way for more effective and personalized treatment strategies. Full article

Malignant Peripheral Nerve Sheath Tumors (MPNSTs) are a deadly subtype of soft tissue sarcoma for which effective therapeutic options are lacking. Currently, the best treatment for MPNSTs is complete surgical resection with wide negative margins, but this is often complicated by the tumor size and location and/or the presence of metastases. Radiation or chemotherapy may be combined with surgery, but patient responses are poor. Targeted treatments, including small-molecule inhibitors of oncogenic proteins such as mitogen-activated protein kinase kinase (MEK), cyclin-dependent kinases 4 and 6 (CDK4/6), and Src-homology 2 domain-containing phosphatase 2 (SHP2), are promising therapeutics for MPNSTs, especially when combined together, but they have yet to gain approval. Immunotherapeutic approaches have been revolutionary for the treatment of some other cancers, but their utility as single agents in sarcoma is limited and not approved for MPNSTs. The immunosuppressive niche of MPNSTs is thought to confer inherent treatment resistance, particularly to immunotherapies. Remodeling an inherently “cold” tumor microenvironment into a “hot” immune milieu to bolster the anti-tumor activity of immunotherapies is of great interest throughout the cancer community. This review focuses on novel therapeutics that target dysregulated factors and pathways in MPNSTs, as well as different types of immunotherapies currently under investigation for this disease. We also consider how certain therapeutics may be combined to remodel the MPNST immune microenvironment and thereby generate a durable anti-tumor immune response to immunotherapy. Full article

Background: Personalized anti-tumor therapy that activates the immune response has demonstrated clinical benefits in various cancers. However, its efficacy against testicular cancer (TC) remains uncertain. This study aims to identify suitable patients for anti-tumor immunotherapy and to uncover potential therapeutic targets in TC for the development of tailored anti-tumor immunotherapy. Methods: Consensus clustering analysis was conducted to delineate immune subtypes, while weighted gene co-expression network analysis (WGCNA), least absolute shrinkage and selection operator (LASSO) regression, and support vector machine (SVM) algorithms were employed to evaluate the potential efficacy of anti-tumor immunotherapy. Candidate immunotherapy targets were systematically identified through multi-gene panel analyses and subsequently validated using molecular biology assays. A prioritized target emerging from cellular screening was further evaluated for its capacity to potentiate anti-tumor immunity. The therapeutic efficacy of this candidate was rigorously confirmed through a comprehensive suite of immunological experiments. Results: Following systematic screening of five candidate genes (WNT11, FAM181B, GRK5, FSCN1, and ECHS1), GRK5 emerged as a promising therapeutic target for immunotherapy based on its distinct functional and molecular associations with immune evasion mechanisms. Cellular functional assays revealed that GRK5 knockdown significantly attenuated the malignant phenotype of testicular cancer cells, as evidenced by reduced proliferative capacity and invasive potential. Complementary immunological validation established that specific targeting of GRK5 with the selective antagonist GRK5-IN-2 disrupts immune evasion pathways in testicular cancer, as quantified by T-cell-mediated cytotoxicity. Conclusions: These findings position GRK5 as a critical modulator of tumor-immune escape, warranting further preclinical exploration of GRK5-IN-2 as a candidate immunotherapeutic agent. Full article

Colorectal cancer (CRC) is a multifactorial disease increasingly recognized for its complex interplay with the gut microbiota. The disruption of microbial homeostasis—dysbiosis—has profound implications for intestinal barrier integrity and host immune function. Pathogenic bacterial species such as Fusobacterium nucleatum, Escherichia coli harboring polyketide synthase (pks) island, and enterotoxigenic Bacteroides fragilis are implicated in CRC through mechanisms involving mucosal inflammation, epithelial barrier disruption, and immune evasion. These pathogens promote pro-tumorigenic inflammation, enhance DNA damage, and suppress effective anti-tumor immunity. Conversely, commensal and probiotic bacteria, notably Lactobacillus and Bifidobacterium species, exert protective effects by preserving epithelial barrier function and priming host immune responses. These beneficial microbes can promote the maturation of dendritic cells, stimulate CD8⁺ T cell cytotoxicity, and modulate regulatory T cell populations, thereby enhancing anti-tumor immunity. The dichotomous role of the microbiota underscores its potential as both a biomarker and a therapeutic target in CRC. Recent advances in studies have explored microbiota-modulating strategies—ranging from dietary interventions and prebiotics to fecal microbiota transplantation (FMT) and microbial consortia—as adjuncts to conventional therapies. Moreover, the composition of the gut microbiome has been shown to influence the responses to immunotherapy and chemotherapy, raising the possibility of microbiome-informed precision oncology therapy. This review synthesizes the current findings on the pathogenic and protective roles of bacteria in CRC and evaluates the translational potential of microbiome-based interventions in shaping future therapeutic paradigms. Full article

Leukemias and lymphomas are hematologic malignancies characterized by complex pathophysiological mechanisms and increasing global incidence. Despite advances in chemotherapy, immunotherapy, and targeted therapies, challenges such as drug resistance and relapse persist, necessitating novel therapeutic strategies. This review explores the cytotoxic potential of venoms derived from snakes, bees, and scorpions against leukemia and lymphoma cells. Numerous venom-derived components, such as L-amino acid oxidases (LAAOs), phospholipases A₂ (PLA₂s), and peptides like melittin, demonstrate selective antitumor activity through mechanisms involving oxidative stress, apoptosis induction, cell cycle arrest, and immunomodulation. These molecules exert their effects via mitochondrial pathways, caspase activation, and inhibition of pro-survival signaling cascades such as NF-κB and PI3K/Akt. Despite promising preclinical results, the clinical translation of these bioactive compounds remains limited due to challenges in standardization, delivery, and safety profiling. This review highlights recent advances in venom research, summarizes key molecular targets, and discusses future directions to harness venom-derived molecules as innovative therapies for hematological cancers. Full article

Background/Objectives: Head and neck squamous cell carcinoma (HNSCC) is the seventh most common cancer, with limited responsiveness to immune checkpoint inhibitors (ICIs). Cancer vaccine therapy is a promising novel immunotherapeutic approach that stimulates tumor-specific T cells. Receptor tyrosine kinase-like orphan receptor 1 (ROR1), which is overexpressed in malignant tumors but minimally expressed in normal tissues, presents a promising target for immunotherapy. This study aimed to evaluate ROR1 as a target for helper T lymphocyte (HTL)-based peptide vaccine immunotherapy in HNSCC. Methods: ROR1 expression in HNSCC tissues was assessed by immunohistochemistry. A novel ROR1-derived epitope (ROR1_403–417) was identified and used to generate ROR1-reactive HTLs. Functional assays measuring IFN-γ and granzyme B secretion, as well as direct cytotoxicity, were performed. The effects of ICIs on HTL activity were also examined. The presence of ROR1-reactive T cells in the peripheral blood of patients with HNSCC was evaluated. Results: ROR1 positivity rates in HNSCC tissues were significantly higher (80.0%) than those in healthy controls (16.7%), and high ROR1 expression correlated with advanced clinical stages. HTL lines recognized the ROR1_403–417 peptide in a human leukocyte antigen (HLA)-DR-restricted manner, secreted effector cytokines, and exhibited direct cytotoxicity against ROR1+ tumor cells. Dual PD-L1/PD-L2 blockade further enhanced HTL responses. ROR1-reactive T cells were detected in the peripheral blood of patients with HNSCC. Conclusions: ROR1 represents a promising target for immunotherapy in HNSCC. The ROR1_403–417 peptide can elicit ROR1-reactive HTLs that exhibit antitumor responses against HNSCC cell lines, which can be enhanced by ICIs. These findings support the potential of ROR1-targeted peptide vaccine therapy for HNSCC. Full article

Background/Objectives: Pancreatic cancer remains the fourth leading cause of cancer-related deaths. While peripheral blood-derived mature dendritic cell (mDC) vaccines have shown potential in eliciting anti-tumor immune responses, clinical efficacy has been limited. This study aimed to enhance the potency and scalability of DC-based immunotherapy by developing an allogeneic DC platform derived from CD34⁺ hematopoietic stem cells (HSCs), genetically engineered to overexpress CD93, CD40L, and CXCL13, followed by maturation and tumor antigen pulsing. Methods: Engineered DCs were generated from CD34⁺ HSCs and matured in vitro after lentiviral transduction of CD93, CD40L, and CXCL13. Tumor lysates were used for antigen pulsing. A scrambled-sequence control DC was used for comparison. In vitro assays were performed to assess T cell activation and tumor cell killing. In vivo efficacy was evaluated using orthotopic pancreatic tumors in BLT and PBMC-humanized NSG mice established with the MiaPaca-2 (MP2) cell line. Results: Engineered DCs significantly enhanced T cell activation and tumor-specific cytotoxicity in vitro compared to control DCs. Antigen pulsing further amplified immune activation. In vivo, treated humanized mice showed increased CD4⁺, CD8⁺, and NK cell frequencies in peripheral blood and within tumors, correlating with reduced tumor burden. Conclusions: Our data shows that the antigen-pulsed, engineered DCs have the potency to activate immune cells, which leads to a significant reduction in pancreatic tumors and therefore could potentially provide an effective therapeutic opportunity for the treatment of pancreatic cancer and other solid tumors. Full article

Introduction: Gastric cancer (GC) is the third leading cause of cancer-related deaths worldwide. Even though surgery and chemotherapy are the mainstay of treatment, immunotherapy, and more specifically anti-tumor vaccination, has gained popularity over the past years due to the lower related toxicity and fewer long-term side effects. Dendritic cell (DC) vaccines have been shown to induce tumor specific cytotoxic T-cell (CTL) responses both in vitro and in vivo; however, due to the nature of the disease, resistance to immunotherapy is often developed. Various modifications, such as the implementation of viral vectors, tumor RNA, or even tumor-specific peptides (neoantigens), have been studied as a means to avoid resistance and enhance the effectiveness of the vaccines. In this review, we aim to assess the effects of neoantigen-loaded DC vaccines (naDCVs) on the immune response against gastric cancer cells. Materials and methods: A thorough literature search was conducted on PubMed and clinicaltrials.gov for studies assessing the efficacy of naDCVs against gastric cancer both in vivo and in vitro. The studies were assessed for eligibility by two independent reviewers based on predetermined inclusion and exclusion criteria. The search was completed following the PRISMA guidelines. Results: Eleven studies were included in our systematic review. In five of the studies, the effects of the naDCVs were tested in vitro; in two and in four they were examined both in vitro and in vivo. The in vitro studies showed that the naDCVs resulted in a more robust immune response against the cancer cells in the study groups compared to the control groups. The in vivo studies conducted on mice showed that tumor volume was reduced in the groups treated with the naDCV compared to the untreated groups. What is more, the cytotoxic effect of CTLs against tumor cells was also increased in the vaccine groups. One of the studies was conducted on humans as a phase I study. The results show increased CTL proliferation and cytokine production in the vaccinated group compared to the control, but no difference regarding the tumor size was observed. Conclusions: Neoantigen-loaded DC vaccines can stimulate a strong immune response against specific gastric cancer cell peptides and enhance tumor cell lysis, therefore hindering or even reversing disease progression, offering great potential for the treatment of patients with gastric cancer. Full article

Background/Objectives: The physiological activation of cytotoxic CD8^pos T cells (CTLs) relies on the engagement of the TCR/CD3 complex with cognate peptide-HLA class I (pHLA-I) on target cells, triggering cell lysis with appropriate cytokine release and minimized off-target toxicity. In contrast, current immunotherapies for CD19-expressing hematological malignancies, such as chimeric antigen receptor (CAR) T cells and bispecific T cell engagers (BiTEs), bypass TCR/pHLA interactions, resulting in CTL hyperactivation and excessive cytokine release, which frequently cause severe immune-related adverse events (irAEs). Thus, there is a pressing need for T cell-based therapies that preserve physiological activation while maintaining antitumor efficacy. Methods: To address this, we developed CD19-ReTARG^TPR, a novel fusion protein consisting of the immunodominant cytomegalovirus (CMV) pp65-derived peptide TPRVTGGAM (TPR) covalently presented by a soluble HLA-B*07:02/β2-microglobulin complex fused to a high-affinity CD19-targeting Fab antibody fragment. The treatment of CD19-expressing cancer cells with CD19-ReTARG^TPR makes them recognizable for pre-existing anti-CMV_pp65 CTLs via physiological TCR-pHLA engagement. Results: Our preclinical data demonstrate that CD19-ReTARG^TPR efficiently redirects anti-CMV CTLs to eliminate CD19-expressing cancer cells, including both established cell lines and primary chronic lymphocytic leukemia (CLL) cells. Unlike CD19-directed CAR T cells or the CD19/CD3 BiTE blinatumomab, CD19-ReTARG^TPR mediated robust cytotoxic activity without triggering supraphysiological cytokine release. Importantly, this approach retained efficacy even against cancer cells with low CD19 expression. Conclusions: In summary, we provide a robust proof-of-concept study and show that CD19-ReTARG^TPR offers a promising alternative strategy for T cell redirection, enabling the selective and effective killing of CD19-expressing malignancies while minimizing cytokine-driven toxicities through physiological CTL activation pathways. Full article