Immunotherapy Strategies Research Articles

Autophagy Blockage Up-Regulates HLA-Class-I Molecule Expression in Lung Cancer and Enhances Anti-PD-L1 Immunotherapy Efficacy.

Immune checkpoint inhibitors have an established role in non-small cell lung cancer (NSCLC) therapy. The loss of HLA-class-I expression allows cancer cell evasion from immune surveillance, disease progression, and failure of immunotherapy. The restoration of HLA-class-I expression may prove to be a game-changer in current immunotherapy strategies. Autophagic activity has been recently postulated to repress HLA-class-I expression in cancer cells. NSCLC cell lines (A549 and H1299) underwent late-stage (chloroquine and bafilomycin) and early-stage autophagy blockage (ULK1 inhibitors and MAP1LC3A silencing). The HLA-class-I expression was assessed with flow cytometry, a Western blot, and RT-PCR. NSCLC tissues were examined for MAP1LC3A and HLA-class-I expression using double immunohistochemistry. CD8+ T-cell cytotoxicity was examined in cancer cells pre-incubated with chloroquine and anti-PD-L1 monoclonal antibodies (Moabs); Results: A striking increase in HLA-class-I expression following incubation with chloroquine, bafilomycin, and IFNγ was noted in A549 and H1299 cancer cells, respectively. This effect was further confirmed in CD133+ cancer stem cells. HLA-class-I, β2-microglobulin, and TAP1 mRNA levels remained stable. Prolonged exposure to chloroquine further enhanced HLA-class-I expression. Similar results were noted following exposure to a ULK1 and a PIKfyve inhibitor. Permanent silencing of the MAP1LC3A gene resulted in enhanced HLA-class-I expression. In immunohistochemistry experiments, double LC3A+/HLA-class-I expression was seldom. Pre-incubation of H1299 cancer cells with chloroquine and anti-PD-L1 MoAbs increased the mean % of apoptotic/necrotic cells from 2.5% to 18.4%; Conclusions: Autophagy blockers acting either at late or early stages of the autophagic process may restore HLA-class-I-mediated antigen presentation, eventually leading to enhanced immunotherapy efficacy.

Present and Future of Immunotherapy for Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) lacks the expression of estrogen receptors (ERs), human epidermal growth factor receptor 2 (HER2), and progesterone receptors (PRs). TNBC has the poorest prognosis among breast cancer subtypes and is more likely to respond to immunotherapy due to its higher expression of PD-L1 and a greater percentage of tumor-infiltrating lymphocytes. Immunotherapy has revolutionized TNBC treatment, especially with the FDA's approval of pembrolizumab (Keytruda) combined with chemotherapy for advanced cases, opening new avenues for treating this deadly disease. Although immunotherapy can significantly improve patient outcomes in a subset of patients, achieving the desired response rate for all remains an unmet clinical goal. Strategies that enhance responses to immune checkpoint blockade, including combining immunotherapy with chemotherapy, molecularly targeted therapy, or radiotherapy, may improve response rates and clinical outcomes. In this review, we provide a short background on TNBC and immunotherapy and explore the different types of immunotherapy strategies that are currently being evaluated in TNBC. Additionally, we review why combination strategies may be beneficial, provide an overview of the combination strategies, and discuss the novel immunotherapeutic opportunities that may be approved in the near future for TNBC.

Targeting CD47 and Angiogenesis Demonstrates Effective Anti-Tumor Effect in Bladder Cancer.

Background: Although immunotherapy has shown potential in cancer treatment, current immunotherapeutics for bladder cancer are limited by a low response rate. Therefore, it is necessary to investigate other suitable immunotherapeutic targets and strategies for bladder cancer. Methods: To evaluate whether CD47 could be a suitable target for bladder cancer immunotherapy, CD47 protein expression levels in 116 bladder cancer tissue samples were assessed by IHC staining. In vitro anti-tumor effect of blocking CD47 was examined by phagocytosis assays. In vivo anti-tumor effects of targeting CD47 and angiogenesis were experimented in the HSPCs-CDX model. Results: We find that CD47 is highly expressed in bladder cancer samples and is associated with poor prognosis. Blocking CD47 could enhance the human PBMC-derived macrophages' phagocytosis of T24 (from 10.40% to 29.70%) and 5637 (from 5.31% to 33.52%) human bladder cancer cells, as well as demonstrate anti-tumor effects in the HSPCs-CDX model (tumor growth inhibition rate, TGI: 33.05%). During CD47 treatment, we observed that the level of angiogenesis increased after CD47 blockade, and it might undermine the effect of CD47 immunotherapy. We then combined CD47 blockade with anti-angiogenic drugs to treat bladder cancer and discovered that inhibiting angiogenesis could further improve the anti-tumor effect of CD47 blockade (TGI: 76.39%). Finally, we tested the anti-tumor effect of co-targeting CD47 and angiogenesis using a bispecific fusion protein, SIRPα-VEGFR1, which successfully inhibited tumor growth to a similar extent as a combination therapy. Conclusions: Our study suggests that targeting CD47 could inhibit the growth of bladder cancer by promoting macrophage-mediated anti-tumor immunity. Moreover, blocking CD47 and angiogenesis could achieve a potent anti-tumor effect and could be an effective immunotherapy strategy for bladder cancer.

ACSL6-activated IL-18R1-NF-κB promotes IL-18-mediated tumor immune evasion and tumor progression.

Aberrant activation of IL-18 signaling regulates tumor immune evasion and progression. However, the underlying mechanism remains unclear. Here, we report that long-chain acyl-CoA synthase 6 (ACSL6) is highly expressed in liver cancer and correlated with poor prognosis. ACSL6 promotes tumor growth, metastasis, and immune evasion mediated by IL-18, independent of its metabolic enzyme activity. Mechanistically, upon IL-18 stimulation, ACSL6 is phosphorylated by ERK2 at S674 and recruits IL-18RAP to interact with IL-18R1, thereby reinforcing the IL-18R1-IL-18RAP heterodimer and triggering NF-κB-dependent gene expression to facilitate tumor development. Furthermore, the up-regulation of CXCL1 and CXCL5 by ACSL6 promotes tumor-associated neutrophil and tumor-associated macrophage recruitment, thereby inhibiting cytotoxic CD8+ T cell infiltration. Ablation or S674A mutation of ACSL6 potentiated anti-PD-1 therapeutic efficacy by increasing the effector activity of intertumoral CD8+ T cells. We revealed that ACSL6 is a potential adaptor that activates IL-18-NF-κB axis-mediated tumor immune evasion and provides valuable insights for developing effective immunotherapy strategies for cancer.

Identification of potential biomarkers for lung adenocarcinoma: a study based on bioinformatics analysis combined with validation experiments.

The prognosis for lung adenocarcinoma (LUAD) remains dismal, with a 5-year survival rate of <20%. Therefore, the purpose of this study was to identify potentially reliable biomarkers in LUAD by machine learning combination with Mendelian randomization (MR). TCGA-LUAD, GSE40791, and GSE31210 were employed this study. Key module differential genes were identified through differentially expressed analysis and weighted gene co-expression network analysis (WGCNA). Furthermore, candidate biomarkers were derived from protein-protein interaction network (PPI) and machine learning. Ultimately, biomarkers were confirmed using MR analysis. In addition, immunohistochemistry was used to detect the expression levels of genes that have a causal relationship to LUAD in the LUAD group and the control group. Cell experiments were conducted to validate the effect of screening genes on proliferation, migration, and apoptosis of LUAD cells. The correlation between the screened genes and immune infiltration was determined by CIBERSORT algorithm. In the end, the gene-related drugs were predicted through the Drug-Gene Interaction database. In total, 401 key module differential genes were obtained by intersecting of 5,702 differentially expressed genes (DEGs) and 406 key module genes. Thereafter, GIMAP6, CAV1, PECAM1, and TGFBR2 were identified. Among them, only TGFBR2 had a significant causal relationship with LUAD (p=0.04, b=-0.06), and it is a protective factor for LUAD. Subsequently, sensitivity analyses showed that there were no heterogeneity and horizontal pleiotropy in the univariate MR results, and the results were not overly sensitive to individual SNP loci, further validating the reliability of univariate Mendelian randomization (UVMR) results. However, no causal relationship was found between them by reverse MR analysis. Meanwhile, TGFBR2 expression was decreased in LUAD group through immunohistochemistry. TGFBR2 can inhibit proliferation and migration of lung adenocarcinoma cell line A549 and promote apoptosis of A549 cells. Immune infiltration analysis suggested a potential link between TGFBR2 expression and immune infiltration. Finally, Irinotecan and Hesperetin were predicted through DGIDB database. In this study, TGFBR2 was identified as a biomarker of LUAD, which provided a new idea for the treatment strategy of LUAD and may aid in the development of personalized immunotherapy strategies.

Adverse reactions associated with nivolumab and small molecule antiangiogenic drugs: A pharmacovigilance analysis.

Immune checkpoint inhibitors, such as nivolumab, combined with small molecule antiangiogenic receptor tyrosine kinase inhibitors (TKIs), present a promising strategy for future immunotherapy. However, combination therapy can lead to specific adverse drug reactions (ADRs) in various clinical settings. Current research on the ADRs associated with combination therapy is limited. Our study aims to assess the safety of combination therapy. We extracted ADR reports on combination therapy from the Food and Drug Administration (FDA) Adverse Event Reporting System database, covering the period from the first quarter of 2012 to the third quarter of 2023, and conducted a large-scale retrospective study. We evaluated ADR risk signals using the reporting odds ratio (ROR) and calculated the Ro/e ratio to compare the differences in the risk of fatal ADRs among various tumour types. We comprehensively reported the occurrence of ADRs in pan-cancer patients undergoing combination therapy. The combination therapy significantly increased the risk of sensitive skin (ROR: 231.43, 95% CI: 55.01-973.72, P < .05), metastatic renal cell carcinoma (ROR: 220.71, 95% CI: 28.99-1695.41, P < .05) and renal cell carcinoma (ROR: 188.22, 95% CI: 44.24-800.85, P < .05). We also compared the differences in ADRs resulting from different small molecule drug combinations, as well as the differences in ADRs among patients with different types of tumours under combination therapy. Furthermore, we analysed the characteristics of patients prone to experiencing fatal ADRs. These results can help enhance understanding of the ADRs commonly associated with combination therapy and assist oncologists in formulating screening protocols.

Targeting SNRNP200-induced splicing dysregulation offers an immunotherapy opportunity for glycolytic triple-negative breast cancer

Metabolic dysregulation is prominent in triple-negative breast cancer (TNBC), yet therapeutic strategies targeting cancer metabolism are limited. Here, utilizing multiomics data from our TNBC cohort (n = 465), we demonstrated widespread splicing deregulation and increased spliceosome abundance in the glycolytic TNBC subtype. We identified SNRNP200 as a crucial mediator of glucose-driven metabolic reprogramming. Mechanistically, glucose induces acetylation at SNRNP200 K1610, preventing its proteasomal degradation. Augmented SNRNP200 then facilitates splicing key metabolic enzyme-encoding genes (GAPDH, ALDOA, and GSS), leading to increased lactic acid and glutathione production. Targeting SNRNP200 with antisense oligonucleotide therapy impedes tumor metabolism and enhances the efficacy of anti-PD-1 therapy by activating intratumoral CD8+ T cells while suppressing regulatory T cells. Clinically, higher SNRNP200 levels indicate an inferior response to immunotherapy in glycolytic TNBCs. Overall, our study revealed the intricate interplay between RNA splicing and metabolic dysregulation, suggesting an innovative combination strategy for immunotherapy in glycolytic TNBCs.

Natural plant-derived polysaccharides targeting macrophage polarization: a promising strategy for cancer immunotherapy.

Tumor associated macrophages (TAMs) are the predominant innate immune cells in the tumor microenvironment (TME). Cytokines induce the differentiation of macrophages into distinct types of TAMs, primarily characterized by two phenotypes: M1-polarized and M2-polarized. Cancer growth is suppressed by M1-polarized macrophages and promoted by M2-polarized macrophages. The regulation of macrophage M1 polarization has emerged as a promising strategy for cancer immunotherapy. Polysaccharides are important bioactive substances found in numerous plants, manifesting a wide range of noteworthy biological actions, such as immunomodulation, anti-tumor effects, antioxidant capabilities, and antiviral functions. In recent years, there has been a significant increase in interest regarding the immunomodulatory and anti-tumor properties of polysaccharides derived from plants. The regulatory impact of polysaccharides on the immune system is mainly associated with the natural immune response, especially with the regulation of macrophages. This review provides a thorough analysis of the regulatory effects and mechanisms of plant polysaccharides on TAMs. Additionally, an analysis of potential opportunities for clinical translation of plant polysaccharides as immune adjuvants is presented. These insights have greatly advanced the research of plant polysaccharides for immunotherapy in tumor-related applications.

Integrated analyses reveal IDO1 as a prognostic biomarker coexpressed with PD-1 on tumor-associated macrophages in esophageal squamous cell carcinoma.

Inhibition of indolamine-2,3-dioxygenase 1 (IDO1) has been proposed as a promising strategy for cancer immunotherapy; however, it has failed in clinical trials. Macrophages in the tumor microenvironment (TME) contribute to immune escape and serve as potential therapeutic targets. This study investigated the expression pattern of IDO1 in TME and its impact on prognosis and therapeutic response of patients with esophageal squamous cell carcinoma (ESCC). RNA sequencing data from 95 patients with ESCC from The Cancer Genome Atlas (TCGA) database were used to explore the prognostic value of IDO1. Bioinformatics tools were used to estimate scores for stromal and immune cells in tumour tissues, abundance of eight immune cell types in TME, and sensitivity of chemotherapeutic drugs and immune checkpoint (IC) blockage. The results were validated using digitalized immunohistochemistry and multiplexed immunofluorescence in ESCC tissue samples obtained from our clinical center. TCGA and validation data suggested that high expression of IDO1 was associated with poor patient survival, and IDO1 was an independent prognostic factor. IDO1 expression positively correlated with macrophages in TME and PDCD1 within diverse IC genes. Single-cell RNA sequencing data analysis and multiplexed immunofluorescence verified the coexpression of IDO1 and PD-1 in tumor-associated macrophages (TAMs). Patients with high IDO1 expression showed increased sensitivity to various chemotherapeutic drugs, while were more likely to resist IC blockage. This study identifies IDO1 as an independent prognostic indicator of OS in patients with ESCC, reveals a compelling connection of IDO1, PD-1, and TAMs, and explores the sensitivity of patients with high IDO1 expression to chemotherapeutic drugs and their resistance to IC blockade. These findings open new avenues for potential targets in ESCC immunotherapy.

Tuning the fluidity and protein corona of ultrasound-responsive liposomal nanovaccines to program T cell immunity in mice

Inducing high levels of antigen-specific CD8α+ T cells in the tumor is beneficial for cancer immunotherapy, but achieving this in a safe and effective manner remains challenging. Here, we have developed a designer liposomal nanovaccine containing a sonosensitizer (LNVS) to efficiently program T cell immunity in mice. Following intravenous injection, LNVS accumulates in the spleen in a protein corona and fluidity-dependent manner, leading to greater frequencies of antigen-specific CD8α+ T cells than soluble vaccines (the mixture of antigens and adjuvants). Meanwhile, some LNVS passively accumulates in the tumor, where it responds to ultrasound (US) to increase the levels of chemokines and adhesion molecules that are beneficial for recruiting CD8α+ T cells to the tumor. LNVS + US induces higher levels of intratumoral antitumor T cells than traditional sonodynamic therapy, regresses established mouse MC38 tumors and orthotopic cervical cancer, and protects cured mice from relapse. Our platform sheds light on the importance of tuning the fluidity and protein corona of naovaccines to program T cell immunity in mice and may inspire new strategies for cancer immunotherapy.

Low-dose SAHA enhances CD8+ T cell-mediated antitumor immunity by boosting MHC I expression in non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) is a highly aggressive type of lung cancer with poor responses to traditional therapies such as surgery, radiotherapy, and chemotherapy. While immunotherapy has become an effective approach for treating multiple types of cancer, solid tumors frequently exhibit immune escape through various mechanisms, including downregulation of MHC I expression. However, whether the upregulation of MHC I expression can improve the immunotherapeutic effect on NSCLC remains unexplored. Suberoylanilide hydroxamic acid (SAHA) is a potent histone deacetylase (HDAC) inhibitor that has been applied clinically to treat lymphoma, but a high dose of SAHA kills tumor cells and normal cells without preference. Here, we report that low-dose SAHA enhances CD8+ T cell-mediated antitumor immunity by upregulating MHC I expression in NSCLC cells. Flow cytometric analysis, quantitative real-time PCR and western blot were used to analyze the expression of MHC I, STAT1 and Smad2/3 in both human and mouse NSCLC cell lines after SAHA treatment. The nuclear translocation of phosphorylated STAT1 and Smad2/3 was investigated by western blot and immunofluorescence staining. The mechanisms underlying STAT1 and Smad2/3 upregulation were analyzed through database searches and chromatin immunoprecipitation-qPCR. Finally, we assessed the antitumor effect of specific CD8+ T cells with SAHA treatment in vivo and in vitro. We showed that low-dose SAHA upregulated the expression of MHC I in NSCLC cell lines without affecting cell viability. We also provided evidence that high levels of MHC I induced by SAHA promoted the activation, proliferation, and cytotoxicity of specific CD8+ T cells in mouse models. Mechanistically, low-dose SAHA increased the levels of H3K9ac and H3K27ac in the promoters of the STAT1, Smad2 and Smad3 genes in NSCLC cells by inhibiting HDAC activity, resulting in elevated expression levels of STAT1, Smad2 and Smad3. The nuclear translocation of phosphorylated STAT1 and Smad2/3 markedly upregulated the expression of MHC I in NSCLC cells. Low-dose SAHA enhances CD8+ T cell-mediated antitumor immunity by boosting MHC I expression in NSCLC cells. Thus, we revealed a key mechanism of SAHA-mediated enhanced antitumor immunity, providing insights into a novel immunotherapy strategy for NSCLC.

Research Progress on the Effects of PI3K/Akt Pathway on Immune Escape

The PI3K/Akt pathway can promote immune escape in tumors, making cancer cells more difficult for the immune system to attack. It is usually possible to regulate the number and function of immune cells by inhibiting apoptosis and T cell activation, and generate immune escape mutations to make cancer cells more resistant to immune monitoring. In-depth understanding of the role of PI3K/Akt pathway in immune escape will help to reveal the mechanism of tumor development, improve the effectiveness of cancer treatment. development, improve the effectiveness of cancer treatment, and restore the immune system's monitoring and attack on cancer cells by inhibiting the activity of PI3K/Akt. In this review, we review the research progress on the effects of G protein-coupled receptor-activated PI3K/Akt pathway on immune escape. This review aims to summarize domestic and international studies that reveal how the PI3K/Akt pathway plays a key role in immune escape, and through in-depth understanding of the role of the PI3K/Akt pathway in immune escape. This review aims to summarize domestic and international studies that reveal how the PI3K/Akt pathway plays a key role in immune escape, and through in-depth understanding of the molecular mechanism, new therapeutic targets can be identified. Scientists from abroad have explored various cancer forms, such as lung, ovarian, and endometrial cancers, etc., so as to provide targeted treatment strategies and increase the applicability of immunotherapy for different cancers; By studying the role of PI3K/Akt pathway, we can explore the potential application of PI3K/Akt pathway for different cancers. By studying the role of PI3K/Akt pathway, we can explore the potential application of existing drugs or new drugs in immunotherapy, so as to improve the diversity of treatment. techniques are combined with clinical data to discover associations between the PI3K/Akt pathway and treatment response in patients to support personalized medicine. Current studies have found that the PI3K/Akt pathway is a key mechanism for immune monitoring of tumor cell escape, and in-depth study of its role is expected to improve the quality of treatment. Current studies have found that the PI3K/Akt pathway is a key mechanism for immune monitoring of tumor cell escape, and in-depth study of its role is expected to improve current immunotherapy strategies and improve patient survival. In the future, whether there are new therapeutic opportunities for PI3K/Akt pathway in immune escape studies, so as to help optimize cancer treatment strategies, improve the efficacy of immunotherapy in future, whether there are new therapeutic opportunities for PI3K/Akt pathway in immune escape studies, so as to help optimize cancer treatment strategies, improve the efficacy of immunotherapy, and improve patient treatment outcomes.

A Magnetically Driven Biodegradable Microsphere with Mass Production Capability for Subunit Vaccine Delivery and Enhanced Immunotherapy.

Subunit vaccines have emerged as a promising strategy in immunotherapy for combating viral infections and cancer. Nevertheless, the clinical application of subunit vaccines is hindered by limitations in antigen delivery efficiency, characterized by rapid clearance and inadequate cellular uptake. Here, a novel subunit vaccine delivery system utilizing ovalbumin@magnetic nanoparticles (OVA@MNPs) encapsulated within biodegradable gelatin methacryloyl (GelMA) microspheres was proposed to enhance the efficacy of antigen delivery. OVA@MNPs-loaded GelMA microspheres, denoted as OMGMs, can be navigated through magnetic fields to deliver subunit vaccines into the lymphatic system efficiently. Moreover, the biodegradable OMGMs enabled the sustained release of subunit vaccines, concentrating OVA around lymph nodes and enhancing the efficacy of induced immune response. OMGMs were produced through a microfluidic droplet generation technique, enabling mass production. In murine models, OMGMs successfully accumulated antigens in lymph nodes abundant in antigen-presenting cells, leading to enhanced cellular and humoral immunity and pronounced antitumor effects with a single booster immunization. In conclusion, these findings highlight the promise of OMGMs as a practical subunit vaccination approach, thus addressing the limitations associated with antigen delivery efficiency and paving the way for advanced immunotherapeutic strategies.

Open-Source Throttling of CD8+ T Cells in Brain with Low-Intensity Focused Ultrasound-Guided Sequential Delivery of CXCL10, IL-2, and aPD-L1 for Glioblastoma Immunotherapy.

Improving clinical immunotherapy for glioblastoma (GBM) relies on addressing the immunosuppressive tumor microenvironment (TME). Enhancing CD8+ T cell infiltration and preventing its exhaustion holds promise for effective GBM immunotherapy. Here, a low-intensity focused ultrasound (LIFU)-guided sequential delivery strategy is developed to enhance CD8+ T cells infiltration and activity in the GBM region. The sequential delivery of CXC chemokine ligand 10 (CXCL10) to recruit CD8+ T cells and interleukin-2 (IL-2) to reduce their exhaustion is termed an "open-source throttling" strategy. Consequently, up to 3.39-fold of CD8+ T cells are observed with LIFU-guided sequential delivery of CXCL10, IL-2, and anti-programmed cell death 1 ligand 1 (aPD-L1), compared to the free aPD-L1 group. The immune checkpoint inhibitors (ICIs) therapeutic efficacy is substantially enhanced by the reversed immunosuppressive TME due to the expansion of CD8+ T cells, resulting in the elimination of tumor, prolonged survival time, and long-term immune memory establishment in orthotopic GBM mice. Overall, LIFU-guided sequential cytokine and ICIs delivery offers an "open-source throttling" strategy of CD8+ T cells, which may present a promising strategy for brain-tumor immunotherapy.

Immune Characteristics and Immunotherapy of HIV-Associated Lymphoma.

In the era of antiretroviral therapy (ART), mortality among people living with the human immunodeficiency virus (HIV) has significantly decreased, yet the population of people living with HIV remains substantial. Among people living with HIV (PLWH), HIV-associated lymphoma (HAL) has surpassed Kaposi's sarcoma to become the most common tumor in this population in developed countries. However, there remains a dearth of comprehensive and systematic understanding regarding HIV-associated lymphomas. This review aims to shed light on the changes in the immune system among PLWH and the characteristics of the immune microenvironment in HIV-associated lymphoma, with a specific focus on the immune system's role in these individuals. Additionally, it seeks to explore recent advancements in immunotherapy for the treatment of HIV-associated lymphoma, intending to enhance strategies for immunotherapy in this specific population.

T lymphocyte‑related immune response and immunotherapy in gastric cancer (Review).

Gastric cancer (GC) remains a global healthcare challenge because of its high incidence and poor prognosis. The efficacy of current chemotherapy regimens for advanced GC is limited. T cells, which have been implicated in the progression of GC, have a significant impact in the tumor microenvironment. With a more detailed understanding of the mechanisms underlying the cancer immunoediting process, immunotherapy may become a promising treatment option for patients with GC. Several clinical trials are currently investigating different mechanisms targeting the tumor immune response. The present review summarized T cell-involved immune responses and various immunotherapy strategies for GC.

Melatonin enhances NK cell function in aged mice by increasing T-bet expression via the JAK3-STAT5 signaling pathway

Natural killer (NK) cells are crucial innate immune cells that provide defense against viruses and tumors. However, aging is associated with alterations in NK cell composition and compromised cell functions. Melatonin, known for its anti-tumor effects, has been reported to improve NK cell function. However, the molecular mechanism underlying melatonin’s effect on senescent NK cells remains unclear. In this study, we aimed to elucidate the mechanism by which melatonin enhances the function of senescent NK cells. Our findings revealed that melatonin significantly increased the number and function of NK cells in aging mice. The results suggest that melatonin enhances NK cell proliferation, degranulation, and IFN-γ secretion. Further investigations demonstrated that melatonin promotes NK cell maturation and activation, mainly via the JAK3/STAT5 signaling pathway, leading to increased expression of T-bet. These discoveries provide a theoretical basis for potential immunotherapy strategies based on melatonin-mediated modulation of NK cell function in aging individuals.

LTBR acts as a novel immune checkpoint of tumor-associated macrophages for cancer immunotherapy.

Tumor-associated macrophages (TAMs) greatly contribute to immune checkpoint inhibitor (ICI) resistance of cancer. However, its underlying mechanisms and whether TAMs can be promising targets to overcome ICI resistance remain to be unveiled. Through integrative analysis of immune multiomics data and single-cell RNA-seq data (iMOS) in lung adenocarcinoma (LUAD), lymphotoxin β receptor (LTBR) is identified as a potential immune checkpoint of TAMs, whose high expression, duplication, and low methylation are correlated with unfavorable prognosis. Immunofluorescence staining shows that the infiltration of LTBR+ TAMs is associated with LUAD stages, immunotherapy failure, and poor prognosis. Mechanistically, LTΒR maintains immunosuppressive activity and M2 phenotype of TAMs by noncanonical nuclear factor kappa B and Wnt/β-catenin signaling pathways. Macrophage-specific knockout of LTBR hinders tumor growth and prolongs survival time via blocking TAMimmunosuppressive activity and M2 phenotype. Moreover, TAM-targeted delivery of LTΒR small interfering RNA improves the therapeutic effect of ICI via reversing TAM-mediated immunosuppression, such as boosting cytotoxic CD8+ T cells and inhibiting granulocytic myeloid-derived suppressor cells infiltration. Taken together, we bring forth an immune checkpoint discovery pipeline iMOS, identify LTBR as a novel immune checkpoint of TAMs, and propose a new immunotherapy strategy by targeting LTBR+ TAMs.

Paulownin elicits anti-tumor effects by enhancing NK cell cytotoxicity through JNK pathway activation.

Paulownin, a natural compound derived from Paulownia tomentosa wood, exhibits various physiological functions, including anti-bacterial and anti-fungal effects. However, the impact of paulownin on natural killer (NK) cell immune activity remains largely unknown. In this study, we investigated the effect of paulownin on NK cell activity both in vitro and in vivo, and explored its potential mechanisms. NK-92 cells were used for in vitro experiments and a BALB/c mouse model with B16F10 cells injected subcutaneously were used for in vivo anti-tumor analysis. We found that paulownin enhanced the cytolytic activity of NK-92 cells against leukemia, human colon, and human lung cancer cell lines. Paulownin treatment increased the expression of the degranulation marker protein CD107a and cytolytic granules, including granzyme B and perforin in NK-92 cells. Moreover, these enhancements of cytotoxicity and the expression of cytolytic granules induced by paulownin were also observed in human primary NK cells. Signaling studies showed that paulownin promoted the phosphorylation of JNK. The increased perforin expression and elevated cytotoxic activity induced by paulownin were effectively inhibited by pre-treatment with a JNK inhibitor. In vivo studies demonstrated that the administration of paulownin suppressed the growth of B16F10 melanoma cells allografted into mice. Paulownin administration promoted the activation of NK cells in the spleen of mice, resulting in enhanced cytotoxicity against YAC-1 cells. Moreover, the anti-tumor effects of paulownin were reduced upon the depletion of NK cells. Therefore, these results suggest that paulownin enhances NK cell cytotoxicity by activating the JNK signaling pathway and provide significant implications for developing new strategies for cancer immunotherapy.

Systemic Therapy for Metastatic Pancreatic Cancer-Current Landscape and Future Directions.

Pancreatic ductal adenocarcinoma (PDAC) is a significant cause of cancer-associated mortality, with a rising global incidence. A paucity of strong predictive risk factors mean screening programmes are difficult to implement. Historically, a lack of identifiable and actionable driver mutations, coupled with a relatively immunosuppressed tumour microenvironment, has led to a reliance on cytotoxic chemotherapy. The NAPOLI-3 trial has reported data supporting consideration of NALIRIFOX as a new first-line standard of care. Kirsten Rat Sarcoma Virus (KRAS) G12D mutations are present in >90% of all PDAC's; exciting breakthroughs in small molecule inhibitors targeting KRAS G12D may open new modalities of treatment, and therapies targeting multiple KRAS mutations are also in early clinical trials. Although immunotherapy strategies to date have been disappointing, combination with chemotherapy and/or small molecule inhibitors hold promise and warrant further exploration.