Epstein-Barr virus latency programs dynamically sensitize B cells to ferroptosis

Ferroptosis, from the virus point of view: opportunities and challenges

Ferroptosis is a new type of cell death, which is mainly dependent on the formation and accumulation of reactive oxygen species and lipid peroxides mediated by iron. It is distinct from other forms of regulation of cell death in morphology, immunology, biochemistry, and molecular biology. Various cell death mechanisms have been observed in many viral infections, and virus-induced cell death has long been considered as a double-edged sword that can inhibit or aggravate viral infections. However, understanding of the role of ferroptosis in various viral infections is limited. Special attention will be paid to the mechanisms of ferroptosis in mediating viral infection and antiviral treatment associated with ferroptosis. In this paper, we outlined the mechanism of ferroptosis. Additionally, this paper also review research on ferroptosis from the perspective of the virus, discussed the research status of ferroptosis in virus infection and classified and summarized research on the interaction between viral infections and ferroptosis.

HDAC3: A Multifaceted Modulator in Immunotherapy Sensitization

Histone deacetylase 3 (HDAC3) has emerged as a critical epigenetic regulator in tumor progression and immune modulation, positioning it as a promising target for enhancing cancer immunotherapy. This work comprehensively explores HDAC3's multifaceted roles, focusing on its regulation of key immune-modulatory pathways such as cGAS-STING, ferroptosis, and the Nrf2/HO-1 axis. These pathways are central to tumor immune evasion, antigen presentation, and immune cell activation. Additionally, the distinct effects of HDAC3 on various immune cell types-including its role in enhancing T cell activation, restoring NK cell cytotoxicity, promoting dendritic cell maturation, and modulating macrophage polarization-are thoroughly examined. These findings underscore HDAC3's capacity to reshape the tumor immune microenvironment, converting immunologically "cold tumors" into "hot tumors" and thereby increasing their responsiveness to immunotherapy. The therapeutic potential of HDAC3 inhibitors is highlighted, both as standalone agents and in combination with immune checkpoint inhibitors, to overcome resistance and improve treatment efficacy. Innovative strategies, such as the development of selective HDAC3 inhibitors, advanced nano-delivery systems, and integration with photodynamic or photothermal therapies, are proposed to enhance treatment precision and minimize toxicity. By addressing challenges such as toxicity, patient heterogeneity, and resistance mechanisms, this study provides a forward-looking perspective on the clinical application of HDAC3 inhibitors. It highlights its significant potential in personalized cancer immunotherapy, paving the way for more effective treatments and improved outcomes for cancer patients.

Ferroptosis-Related Gene Signatures: Prognostic Role in HPV-Positive Oropharyngeal Squamous Cell Carcinoma

BACKGROUND

Despite advances in the management of head and neck squamous cell carcinoma (HNSCC), prognostic models and treatment strategies remain inadequate, particularly for HPV-positive oropharyngeal squamous cell carcinoma (OPSCC). The rising incidence of HPV-positive OPSCC highlights an urgent need for innovative therapeutic approaches. Ferroptosis, a regulated form of non-apoptotic cell death, has gained attention for its role in cancer progression, but its potential as a prognostic and therapeutic target in HPV-positive OPSCC remains largely unexplored. This study investigates the role of ferroptosis in HPV-positive OPSCC, aiming to identify prognostic markers and provide insights into potential therapeutic strategies that could improve patient outcomes.

METHODS

Thirteen ferroptosis gene expression signatures were retrieved from the literature, and their performance and association to the immune microenvironment were validated on a meta-analysis of 267 HPV-positive cases (Metanalysis-HPV267) and 286 samples from the BD2Decide project (BD2-HPV286).

RESULTS

Our analysis revealed that specific ferroptosis-related gene expression signatures, particularly FER3, FER4, FER6, and FER12, are significantly associated (p-value < 0.05) with high-risk patient groups and adverse tumor microenvironment features, including suppressed immune activity and enhanced stromal involvement. Elevated expression of CAV1, a ferroptosis suppressor, further delineates high-risk profiles.

CONCLUSIONS

These findings highlight the prognostic significance of ferroptosis in stratifying patients and identifying those with poorer clinical outcomes. Targeting ferroptosis pathways represents a novel and promising approach to addressing the unmet need for effective prognostic and therapeutic strategies in HPV-positive OPSCC. Future research should focus on translating these findings into clinical applications to advance precision oncology and improve outcomes for this growing patient population.

Ferroptosis contributes to immunosuppression

As a novel form of cell death, ferroptosis is mainly regulated by the accumulation of soluble iron ions in the cytoplasm and the production of lipid peroxides and is closely associated with several diseases, including acute kidney injury, ischemic reperfusion injury, neurodegenerative diseases, and cancer. The term "immunosuppression" refers to various factors that can directly harm immune cells' structure and function and affect the synthesis, release, and biological activity of immune molecules, leading to the insufficient response of the immune system to antigen production, failure to successfully resist the invasion of foreign pathogens, and even organ damage and metabolic disorders. An immunosuppressive phase commonly occurs in the progression of many ferroptosis-related diseases, and ferroptosis can directly inhibit immune cell function. However, the relationship between ferroptosis and immunosuppression has not yet been published due to their complicated interactions in various diseases. Therefore, this review deeply discusses the contribution of ferroptosis to immunosuppression in specific cases. In addition to offering new therapeutic targets for ferroptosis-related diseases, the findings will help clarify the issues on how ferroptosis contributes to immunosuppression.

Multiple sclerosis and infection: history, EBV, and the search for mechanism

SUMMARYInfection has long been hypothesized as the cause of multiple sclerosis (MS), and recent evidence for Epstein-Barr virus (EBV) as the trigger of MS is clear and compelling. This clarity contrasts with yet uncertain viral mechanisms and their relation to MS neuroinflammation and demyelination. As long as this disparity persists, it will invigorate virologists, molecular biologists, immunologists, and clinicians to ascertain how EBV potentiates MS onset, and possibly the disease's chronic activity and progression. Such efforts should take advantage of the diverse body of basic and clinical research conducted over nearly two centuries since the first clinical descriptions of MS plaques. Defining the contribution of EBV to the complex and multifactorial pathology of MS will also require suitable experimental models and techniques. Such efforts will broaden our understanding of virus-driven neuroinflammation and specifically inform the development of EBV-targeted therapies for MS management and, ultimately, prevention.

Human cytomegalovirus RNA2.7 inhibits ferroptosis by upregulating ferritin and GSH via promoting ZNF395 degradation

Human cytomegalovirus (HCMV) is a herpes virus with a long replication cycle. HCMV encoded long non-coding RNA termed RNA2.7 is the dominant transcript with a length of about 2.5kb, accounting for 25% of total viral transcripts. Studies have shown that HCMV RNA2.7 inhibits apoptosis caused by infection. The effect of RNA2.7 on other forms of cell death is still unclear. In this work, we found that RNA2.7 deletion significantly decreased the viability of HCMV-infected cells, while treatment with ferroptosis inhibitor Fer-1 rescued the infection-induced cell death, demonstrating an anti-ferroptosis role of RNA2.7. The results further showed that RNA2.7 inhibited ferroptosis via enhancing Ferritin Heavy Chain 1 (FTH1) and Solute Carrier Family 7 Member 11 (SLC7A11) expression in Erastin treated cells without involving other viral components. Pooled Genome-wide CRISPR screening revealed zinc finger protein 395 (ZNF395) as a new regulator repressing the expression of FTH1 and SLC7A11. HCMV RNA2.7 promoted proteasome-mediated degradation of ZNF395 that resulted in upregulation of FTH1 and SLC7A11 to inhibit ferroptosis, therefore maintain survival in host cells and complete replication of virus.

Bioactive polysaccharides mediate ferroptosis to modulate tumor immunotherapy

Polysaccharides from diverse origins exhibit notable bioactivities, particularly their capacity to exert antitumor and immune-enhancing effects. Concurrently, ferroptosis emerges as a distinctive form of regulated cell death characterized by iron-dependent lipid peroxidation, potentially influencing the demise of specific tumor cells and organismal homeostasis. Recent scholarly attention has increasingly focused on utilizing polysaccharides to modulate tumor cell ferroptosis and manipulate cellular immune responses. This article provides an in-depth analysis of contemporary research concerning using polysaccharides to augment antitumor immunity and combat malignancies. Central to our discourse is examining the pivotal role of polysaccharides in mediating ferroptosis, bolstering immune surveillance, and elucidating the interplay between polysaccharides and antitumor immunity. Furthermore, a comprehensive synthesis of the multifaceted roles of polysaccharides in antitumor and immunomodulatory contexts is provided. Recent advances in understanding how polysaccharides enhance immune function by inducing ferroptosis cell death are explained. Lastly, unresolved inquiries are outlined, and potential avenues for future research are proposed, focusing on the translational applications of polysaccharides in antitumor immunotherapy.

Epstein-Barr virus-driven lymphoproliferation in inborn errors of immunity: a diagnostic and therapeutic challenge

INTRODUCTION

Inborn errors of immunity (IEI) are a group of genetically heterogeneous disorders with a wide-ranging clinical phenotype, varying from increased predisposition to infections to dysregulation of the immune system, including autoimmune phenomena, autoinflammatory disorders, lymphoproliferation, and malignancy. Lymphoproliferative disorder (LPD) in IEI refers to the nodal or extra-nodal and persistent or recurrent clonal or non-clonal proliferation of lymphoid cells in the clinical context of an inherited immunodeficiency or immune dysregulation. The Epstein-Barr virus (EBV) plays a significant role in the etiopathogenesis of LPD in IEIs. In patients with specific IEIs, lack of immune surveillance can lead to an uninhibited proliferation of EBV-infected cells that may result in chronic active EBV infection, hemophagocytic lymphohistiocytosis, and LPD, particularly lymphomas.

AREAS COVERED

We intend to discuss the pathogenesis, diagnosis, and treatment modalities directed toward EBV-associated LPD in patients with distinct IEIs.

EXPERT OPINION

EBV-driven lymphoproliferation in IEIs presents a diagnostic and therapeutic problem that necessitates a comprehensive understanding of host-pathogen interactions, immune dysregulation, and personalized treatment approaches. A multidisciplinary approach involving immunologists, hematologists, infectious disease specialists, and geneticists is paramount to addressing the diagnostic and therapeutic challenges posed by this intriguing yet formidable clinical entity.

Mitochondrial Dysfunction and Metabolic Disturbances Induced by Viral Infections

Viruses are intracellular parasites that utilize organelles, signaling pathways, and the bioenergetics machinery of the cell to replicate the genome and synthesize proteins to build up new viral particles. Mitochondria are key to supporting the virus life cycle by sustaining energy production, metabolism, and synthesis of macromolecules. Mitochondria also contribute to the antiviral innate immune response. Here, we describe the different mechanisms involved in virus-mitochondria interactions. We analyze the effects of viral infections on the metabolism of glucose in the Warburg phenotype, glutamine, and fatty acids. We also describe how viruses directly regulate mitochondrial function through modulation of the activity of the electron transport chain, the generation of reactive oxygen species, the balance between fission and fusion, and the regulation of voltage-dependent anion channels. In addition, we discuss the evasion strategies used to avoid mitochondrial-associated mechanisms that inhibit viral replication. Overall, this review aims to provide a comprehensive view of how viruses modulate mitochondrial function to maintain their replicative capabilities.

Defective Integrator activity shapes the transcriptome of patients with multiple sclerosis

HP1α/CBX5 is an epigenetic regulator with a suspected role in multiple sclerosis (MS). Here, using high-depth RNA sequencing on monocytes, we identified a subset of MS patients with reduced CBX5 expression, correlating with progressive stages of the disease and extensive transcriptomic alterations. Examination of rare non-coding RNA species in these patients revealed impaired maturation/degradation of U snRNAs and enhancer RNAs, indicative of reduced activity of the Integrator, a complex with suspected links to increased MS risk. At protein-coding genes, compromised Integrator activity manifested in reduced pre-mRNA splicing efficiency and altered expression of genes regulated by RNA polymerase II pause-release. Inactivation of Cbx5 in the mouse mirrored most of these transcriptional defects and resulted in hypersensitivity to experimental autoimmune encephalomyelitis. Collectively, our observations suggested a major contribution of the Integrator complex in safeguarding against transcriptional anomalies characteristic of MS, with HP1α/CBX5 emerging as an unexpected regulator of this complex's activity. These findings bring novel insights into the transcriptional aspects of MS and provide potential new criteria for patient stratification.

The Emerging Role of Ferroptosis in EBV-Associated Cancer: Implications for Cancer Therapy

Ferroptosis is a novel and iron-dependent form of programmed cell death, which has been implicated in the pathogenesis of various human cancers. EBV is a well-recognized oncogenic virus that controls multiple signaling pathways within the host cell, including ferroptosis signaling. Recent studies show that inducing ferroptosis could be an efficient therapeutic strategy for EBV-associated tumors. This review will firstly describe the mechanism of ferroptosis, then summarize EBV infection and EBV-associated tumors, as well as the crosstalk between EBV infection and the ferroptosis signaling pathway, and finally discuss the role and potential application of ferroptosis-related reagents in EBV-associated tumors.

Engineered small extracellular vesicle-mediated ferroptosis: A new frontier in cancer immunotherapy

Ferroptosis is a novel iron-dependent form of cell death discovered in recent years, characterized by the accumulation of ferrous iron, the production of reactive oxygen species (ROS) through the Fenton reaction, and lipid peroxidation, ultimately leading to the disruption of the antioxidant system and cell membrane damage. Extensive research has found that ferroptosis plays a significant role in regulating tumor cell immune evasion, tumor development, and remodeling the tumor microenvironment. Small Extracellular vesicles (sEVs), carrying various bioactive molecules (ncRNA, DNA, proteins), are key nanoscale mediators of intercellular communication. Increasing evidence confirms that EVs can regulate the ferroptosis pathway in tumors, promoting tumor cell immune evasion and reshaping the tumor microenvironment. This article aims to comprehensively review the key mechanisms by which sEVs mediate ferroptosis in cancer and provide new insights into targeting tumor immunotherapy.

ROS Induced by Aphrocallistes vastus Lectin Enhance Oncolytic Vaccinia Virus Replication and Induce Apoptosis in Hepatocellular Carcinoma Cells

Oncolytic virotherapy is expected to provide a new treatment strategy for cancer. Aphrocallistes vastus lectin (AVL) is a Ca2+-dependent lectin receptor containing the conserved domain of C-type lectin and the hydrophobic N-terminal region, which can bind to the bird's nest glycoprotein and D-galactose. Our previous studies suggested that the oncolytic vaccinia virus (oncoVV) armed with the AVL gene exerted remarkable replication and antitumor effects in vitro and in vivo. In this study, we found that oncoVV-AVL may reprogram the metabolism of hepatocellular carcinoma cells to promote ROS, and elevated ROS subsequently promoted viral replication and induced apoptosis. This study will provide a new theoretical basis for the application of oncoVV-AVL in liver cancer.

Transcriptome analysis of Burkitt lymphoma cells treated with anti-convulsant drugs that are inhibitors of Epstein-Barr virus lytic reactivation

Herpesviruses have two distinct life cycle stages, latency and lytic replication. Epstein-Barr virus (EBV), a gamma-herpesvirus, establishes latency in vivo and in cultured cells. Cell lines harboring latent EBV can be induced into the lytic cycle by treatment with chemical inducing agents. In the Burkitt lymphoma cell line HH514-16 the viral lytic cycle is triggered by butyrate, a histone deacetylase (HDAC) inhibitor. Butyrate also alters expression of thousands of cellular genes. However, valproic acid (VPA), another HDAC inhibitor with global effects on cellular gene expression blocks EBV lytic gene expression in Burkitt lymphoma cell lines. Valpromide (VPM), an amide derivative of VPA, is not an HDAC inhibitor, but like VPA blocks induction of the EBV lytic cycle. VPA and VPM are the first examples of inhibitors of initial stages of lytic reactivation. We compared the effects of VPA and VPM, alone and in combination with butyrate, on host cellular gene expression using whole transcriptome analysis (RNA-seq). Gene expression was analyzed 6 h after addition of the compounds, a time before the first EBV lytic transcripts are detected. The results address two alternative, yet possibly complementary, mechanisms for regulation of EBV lytic reactivation. First, cellular genes that were up- or down-regulated by butyrate, but no longer altered in the presence of VPA or VPM, represent genes that correlated with EBV lytic reactivation. Second, genes regulated similarly by VPA and VPM in the absence and presence of butyrate are candidates for suppressors of EBV reactivation. Two genes upregulated by the lytic cycle inhibitors, CHAC1 and SLC7A11, are related to redox status and the iron-dependent cell death pathway ferroptosis. This study generates new hypotheses for control of the latency to lytic cycle switch of EBV and provides the first description of effects of the anti-convulsant drug VPM on global human cellular gene expression.

Ferroptosis in viral infection: a potential therapeutic target

Ferroptosis, known as a type of programmed cell death that is iron dependent, is characterized by intracellular iron accumulation, glutathione depletion, glutathione peroxidase inactivation and lipid peroxidation. More and more research in recent years has demonstrated the tight connection between viral infections and ferroptosis. This article reviews the potential role and mechanism of ferroptosis in viral infection, and these findings will help in the prevention and treatment of the virus.

Characterization of target gene regulation by the two Epstein-Barr virus oncogene LMP1 domains essential for B-cell transformation

IMPORTANCE

Epstein-Barr virus (EBV) causes multiple human cancers, including B-cell lymphomas. In cell culture, EBV converts healthy human B-cells into immortalized ones that grow continuously, which model post-transplant lymphomas. Constitutive signaling from two cytoplasmic tail domains of the EBV oncogene latent membrane protein 1 (LMP1) is required for this transformation, yet there has not been systematic analysis of their host gene targets. We identified that only signaling from the membrane proximal domain is required for survival of these EBV-immortalized cells and that its loss triggers apoptosis. We identified key LMP1 target genes, whose abundance changed significantly with loss of LMP1 signals, or that were instead upregulated in response to switching on signaling by one or both LMP1 domains in an EBV-uninfected human B-cell model. These included major anti-apoptotic factors necessary for EBV-infected B-cell survival. Bioinformatics analyses identified clusters of B-cell genes that respond differently to signaling by either or both domains.

Ferroptosis and tumor immunity: In perspective of the major cell components in the tumor microenvironment

Ferroptosis is an iron-dependent form of cell death driven by lipid peroxidation, which is morphologically, biochemically, and genetically distinct from apoptosis, necrosis, and autophagy. Mounting studies on the essential role of ferroptosis have been published in the progression of solid tumors, metastasis, therapy, and therapy resistance. Studies showed that ferroptosis is a "double-edged sword" in tumor immunity, which means it may have both tumor-antagonizing and tumor-promoting functions. The tumor microenvironment (TME) comprises not only tumor cells but also surrounding immune cells, stromal cells, as well as noncellular components such as the extracellular matrix (ECM), cytokines, growth factors, and extracellular vesicles (EVs). In the complex and diverse condition in TME where tumor cells grow, changes in each constituent may impact tumor destiny differently. Recently, several studies have revealed the interaction between ferroptosis and different constituents in TME. Both tumor cells and nontumor cells have a dual role in tumor immunity and influence tumor progression through ferroptosis. Herein, this review aims at summarizing the role of ferroptosis in tumor immunity based on TME, focusing on the mechanisms of the interaction between the ferroptosis and the different constituents in TME, illuminating how ferroptosis plays its role in promoting or antagonizing tumors by acting with varying components in TME and proposing several questions in immunomodulatory effects of ferroptosis and ferroptosis-associated immunotherapy.

Mechanisms of ferroptosis and targeted therapeutic approaches in lymphoma

Lymphoma is the sixth most common type of cancer worldwide. Under the current treatment standards, patients with lymphoma often fail to respond to treatment or relapse early and require further therapy. Hence, novel therapeutic strategies need to be explored and our understanding of the molecular underpinnings of lymphomas should be expanded. Ferroptosis, a non-apoptotic regulated cell death, is characterized by increased reactive oxygen species and lipid peroxidation due to metabolic dysfunction. Excessive or lack of ferroptosis has been implicated in tumor development. Current preclinical evidences suggest that ferroptosis participates in tumorigenesis, progression, and drug resistance of lymphoma, identifying a potential biomarker and an attractive molecular target. Our review summarizes the core mechanisms and regulatory networks of ferroptosis and discusses existing evidences of ferroptosis induction for the treatment of lymphoma, with intent to provide a framework for understanding the role of ferroptosis in lymphomagenesis and a new perspective of lymphoma treatment.

The mechanism of ferroptosis and its related diseases

Ferroptosis, a regulated form of cellular death characterized by the iron-mediated accumulation of lipid peroxides, provides a novel avenue for delving into the intersection of cellular metabolism, oxidative stress, and disease pathology. We have witnessed a mounting fascination with ferroptosis, attributed to its pivotal roles across diverse physiological and pathological conditions including developmental processes, metabolic dynamics, oncogenic pathways, neurodegenerative cascades, and traumatic tissue injuries. By unraveling the intricate underpinnings of the molecular machinery, pivotal contributors, intricate signaling conduits, and regulatory networks governing ferroptosis, researchers aim to bridge the gap between the intricacies of this unique mode of cellular death and its multifaceted implications for health and disease. In light of the rapidly advancing landscape of ferroptosis research, we present a comprehensive review aiming at the extensive implications of ferroptosis in the origins and progress of human diseases. This review concludes with a careful analysis of potential treatment approaches carefully designed to either inhibit or promote ferroptosis. Additionally, we have succinctly summarized the potential therapeutic targets and compounds that hold promise in targeting ferroptosis within various diseases. This pivotal facet underscores the burgeoning possibilities for manipulating ferroptosis as a therapeutic strategy. In summary, this review enriched the insights of both investigators and practitioners, while fostering an elevated comprehension of ferroptosis and its latent translational utilities. By revealing the basic processes and investigating treatment possibilities, this review provides a crucial resource for scientists and medical practitioners, aiding in a deep understanding of ferroptosis and its effects in various disease situations.

Characterization of Target Gene Regulation by the Two Epstein-Barr Virus Oncogene LMP1 Domains Essential for B-cell Transformation

The Epstein-Barr virus (EBV) oncogene latent membrane protein 1 (LMP1) mimics CD40 signaling and is expressed by multiple malignancies. Two LMP1 C-terminal cytoplasmic tail regions, termed transformation essential sites (TES) 1 and 2, are critical for EBV transformation of B lymphocytes into immortalized lymphoblastoid cell lines (LCL). However, TES1 versus TES2 B-cell target genes have remained incompletely characterized, and whether both are required for LCL survival has remained unknown. To define LCL LMP1 target genes, we profiled transcriptome-wide effects of acute LMP1 CRISPR knockout (KO) prior to cell death. To then characterize specific LCL TES1 and TES2 roles, we conditionally expressed wildtype, TES1 null, TES2 null or double TES1/TES2 null LMP1 alleles upon endogenous LMP1 KO. Unexpectedly, TES1 but not TES2 signaling was critical for LCL survival. The LCL dependency factor cFLIP, which plays obligatory roles in blockade of LCL apoptosis, was highly downmodulated by loss of TES1 signaling. To further characterize TES1 vs TES2 roles, we conditionally expressed wildtype, TES1 and/or TES2 null LMP1 alleles in two Burkitt models. Systematic RNAseq analyses revealed gene clusters that responded more strongly to TES1 versus TES2, that respond strongly to both or that are oppositely regulated. Robust TES1 effects on cFLIP induction were again noted. TES1 and 2 effects on expression of additional LCL dependency factors, including BATF and IRF4, and on EBV super-enhancers were identified. Collectively, these studies suggest a model by which LMP1 TES1 and TES2 jointly remodel the B-cell transcriptome and highlight TES1 as a key therapeutic target.

Ferroptosis and WDFY4 as novel targets for immunotherapy of lung adenocarcinoma

BACKGROUND

Lung cancer exhibits the world's highest mortality rate among malignant cancers worldwide, thereby presenting a significant global challenge in terms of reducing patient mortality. In the field of oncology, targeted immunotherapy has emerged as a novel therapeutic approach for lung cancer. This study aims to explore potential targets for immunotherapy in lung adenocarcinoma (LUAD) through the analysis of Ferroptosis Index (FPI) and Single Cell RNA-Sequencing (scRNA-seq) data. The findings of this research can potentially offer valuable insights for improving LUAD immunotherapy strategies and informing clinical decision-making.

METHODS

Firstly, the relationship between survival and ferroptosis in LUAD patients was analyzed by FPI. Subsequently, the association between ferroptosis and infiltration and regulation of immune cells was explored by immune infiltration analysis and correlation statistics. Lastly, the relationship between major infiltrating immune cell populations and related pathways and prognosis of LUAD patients was analyzed by GSEA and GSVA. To screen out core genes regulating infiltration of immune cell populations, scRNA-seq data of cancer and para-cancerous tissues of LUAD patients were downloaded, followed by cell clustering analysis, cell identification of core subpopulations, pseudotime analysis, single-cell GSVA and pathway enrichment analysis, and identification and functional analysis of core regulatory genes. Moreover, the expression levels of core functional genes in LUAD tissue microarray were detected by immunohistochemistry, and its relationship with the prognosis of LUAD patients was verified. Finally, we used lentivirus with WDFY4 to transfect LUAD A549 cells. CCK-8, flow cytometry apoptosis detection, Scratch wound healing assay, Transwell migration assay, Xenograft nude mice model, immunohistochemical analysis and other experimental methods were used to explore the biological effects of WDFY4 on LUAD in vitro and in vivo.

RESULTS

Survival analysis of FPI values in LUAD patients revealed a positive correlation between smaller FPI values and longer overall survival. Immuno-infiltration analysis and its correlation with FPI values revealed that B cells were most strongly associated with ferroptosis. Ferroptosis of cancer cells could promote infiltration and activation of B cell populations, and LUAD patients with more infiltration of B cell populations had longer long-term survival. scRNA-seq data analysis indicated that the B cell population is one of the major cell populations infiltrated by immune cells in LUAD. During the later phases of B cell differentiation in LUAD, there was a decrease in the expression levels of ACAP1, LINC00926, TLR10, MS4A1, WDFY4, and TRIM22 genes, whereas the expression levels of TMEM59, TP53INP1, and METTL7A genes were elevated. The protein-protein interaction (PPI) network analysis indicated that WDFY4 plays a crucial role in regulating B cell differentiation in LUAD. Immunohistochemical analysis of LUAD tissue microarray revealed a significant downregulation of WDFY4 expression, which was closely related to the occurrence sites of LUAD. Moreover, LUAD patients with a low WDFY4 expression exhibited a poorer prognosis. Additionally, experimental findings demonstrated that the overexpression of WDFY4 could inhibit the proliferation and metastasis of A549 cells while promoting apoptosis. It was also confirmed that WDFY4 could inhibit cancer growth in vivo.

CONCLUSIONS

The results indicate that promoting infiltration and activation of B cell populations could improve the long-term survival of LUAD patients, thereby offering a potential novel immunotherapeutic approach for LUAD. Besides, the promotion of cancer cell ferroptosis and upregulation of WDFY4 expression have been shown to induce the infiltration and activation of B cell populations. Furthermore, the overexpression of WDFY4 can significantly inhibit the growth of lung adenocarcinoma in vitro and in vivo, highlighting its potential as a target for immunotherapy in LUAD.

The screening, identification, design and clinical application of tumor-specific neoantigens for TCR-T cells

Recent advances in neoantigen research have accelerated the development of tumor immunotherapies, including adoptive cell therapies (ACTs), cancer vaccines and antibody-based therapies, particularly for solid tumors. With the development of next-generation sequencing and bioinformatics technology, the rapid identification and prediction of tumor-specific antigens (TSAs) has become possible. Compared with tumor-associated antigens (TAAs), highly immunogenic TSAs provide new targets for personalized tumor immunotherapy and can be used as prospective indicators for predicting tumor patient survival, prognosis, and immune checkpoint blockade response. Here, the identification and characterization of neoantigens and the clinical application of neoantigen-based TCR-T immunotherapy strategies are summarized, and the current status, inherent challenges, and clinical translational potential of these strategies are discussed.

The Impact of Co-Infections for Human Gammaherpesvirus Infection and Associated Pathologies

The two oncogenic human gammaherpesviruses Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) cause significant disease burden, particularly in immunosuppressed individuals. Both viruses display latent and lytic phases of their life cycle with different outcomes for their associated pathologies. The high prevalence of infectious diseases in Sub-Saharan Africa (SSA), particularly HIV/AIDS, tuberculosis, malaria, and more recently, COVID-19, as well as their associated inflammatory responses, could potentially impact either virus' infectious course. However, acute or lytically active EBV and/or KSHV infections often present with symptoms mimicking these predominant diseases leading to misdiagnosis or underdiagnosis of oncogenic herpesvirus-associated pathologies. EBV and/or KSHV infections are generally acquired early in life and remain latent until lytic reactivation is triggered by various stimuli. This review summarizes known associations between infectious agents prevalent in SSA and underlying EBV and/or KSHV infection. While presenting an overview of both viruses' biphasic life cycles, this review aims to highlight the importance of co-infections in the correct identification of risk factors for and diagnoses of EBV- and/or KSHV-associated pathologies, particularly in SSA, where both oncogenic herpesviruses as well as other infectious agents are highly pervasive and can lead to substantial morbidity and mortality.

EBV-encoded miRNAs BHRF1-1 and BART2-5p aggravate post- transplant lymphoproliferative disorder via LZTS2-PI3K-AKT axis

Post-transplant lymphoproliferative disorder (PTLD) is one of the most serious complications after transplantation. Epstein-Barr virus (EBV) is a key pathogenic driver of PTLD. About 80% of PTLD patients are EBV positive. However, the accuracy of preventing and diagnosing EBV-PTLD by monitoring EBV DNA load is limited. Therefore, new diagnostic molecular markers are urgently needed. EBV-encoded miRNAs can regulate a variety of EBV-associated tumors and are expected to be potential diagnostic markers and therapeutic targets. We found BHRF1-1 and BART2-5p were significantly elevated in EBV-PTLD patients, functionally promoting proliferation and inhibiting apoptosis in EBV-PTLD. Mechanistically, we first found that LZTS2 acts as a tumor suppressor gene in EBV-PTLD, and BHRF1-1 and BART2-5p can simultaneously inhibit LZTS2 and activate PI3K-AKT pathway. This study shows that BHRF1-1 and BART2-5p can simultaneously inhibit the expression of tumor suppressor LZTS2, and activate the PI3K-AKT pathway, leading to the occurrence and development of EBV-PTLD. Therefore, BHRF1-1 and BART2-5p are expected to be potential diagnostic markers and therapeutic targets for EBV-PTLD patients.

Targeting Metabolic Vulnerabilities in Epstein-Barr Virus-Driven Proliferative Diseases

The metabolism of cancer cells and Epstein-Barr virus (EBV) infected cells have remarkable similarities. Cancer cells frequently reprogram metabolic pathways to augment their ability to support abnormal rates of proliferation and promote intra-organismal spread through metastatic invasion. On the other hand, EBV is also capable of manipulating host cell metabolism to enable sustained growth and division during latency as well as intra- and inter-individual transmission during lytic replication. It comes as no surprise that EBV, the first oncogenic virus to be described in humans, is a key driver for a significant fraction of human malignancies in the world (~1% of all cancers), both in terms of new diagnoses and attributable deaths each year. Understanding the contributions of metabolic pathways that underpin transformation and virus replication will be important for delineating new therapeutic targets and designing nutritional interventions to reduce disease burden. In this review, we summarise research hitherto conducted on the means and impact of various metabolic changes induced by EBV and discuss existing and potential treatment options targeting metabolic vulnerabilities in EBV-associated diseases.

Identification and validation of ferroptosis-related genes in patients infected with dengue virus: implication in the pathogenesis of DENV

Ferroptosis, an iron-dependent form of regulated cell death, has been associated with many virus infections. However, the role of ferroptosis in dengue virus (DENV) infection remains to be clarified. In our study, a dengue fever microarray dataset (GSE51808) of whole blood samples was downloaded from the Gene Expression Omnibus (GEO), and a list of ferroptosis related genes (FRGs) was extracted from the FerrDb. We identified 37 ferroptosis-related differentially expressed genes (FR-DEGs) in DENV-infected patient blood samples compared to healthy individuals. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses as well as protein-protein interaction (PPI) network of FR-DEGs revealed that these 37 FR-DEGs were mainly related to the C-type lectin receptor and p53 signaling pathway. Nine out of the 37 FR-DEGs (HSPA5, CAV1, HRAS, PTGS2, JUN, IL6, ATF3, XBP1, and CDKN2A) were hub genes, of which 5 were validated by qRT-PCR in DENV-infected HepG2 cells. Finally, using miRNA-mRNA regulatory network, we identified has-miR-124-3p and has-miR-16-5p as the most critical miRNAs in regulating the expression of these hub genes. In conclusion, our findings demonstrated that 5 FR-DEGs, JUN, IL6, ATF3, XBP1, and CDKN2A, and two miRNAs, has-miR-124-3p and has-miR-16-5p may implicate an essential role of ferroptosis in DENV infection, and further studies are warranted to explore the underlying mechanisms.

Herpes Simplex Virus 1-Induced Ferroptosis Contributes to Viral Encephalitis

Herpes simplex virus 1 (HSV-1) is a DNA virus belonging to the family Herpesviridae. HSV-1 infection causes severe neurological disease in the central nervous system (CNS), including encephalitis. Ferroptosis is a nonapoptotic form of programmed cell death that contributes to different neurological inflammatory diseases. However, whether HSV-1 induces ferroptosis in the CNS and the role of ferroptosis in viral pathogenesis remain unclear. Here, we demonstrate that HSV-1 induces ferroptosis, as hallmarks of ferroptosis, including Fe²⁺ overload, reactive oxygen species (ROS) accumulation, glutathione (GSH) depletion, lipid peroxidation, and mitochondrion shrinkage, are observed in HSV-1-infected cultured human astrocytes, microglia cells, and murine brains. Moreover, HSV-1 infection enhances the E3 ubiquitin ligase Keap1 (Kelch-like ECH-related protein 1)-mediated ubiquitination and degradation of nuclear factor E2-related factor 2 (Nrf2), a transcription factor that regulates the expression of antioxidative genes, thereby disturbing cellular redox homeostasis and promoting ferroptosis. Furthermore, HSV-1-induced ferroptosis is tightly associated with the process of viral encephalitis in a mouse model, and the ferroptosis-activated upregulation of prostaglandin-endoperoxide synthase 2 (PTGS2) and prostaglandin E₂ (PGE₂) plays an important role in HSV-1-caused inflammation and encephalitis. Importantly, the inhibition of ferroptosis by a ferroptosis inhibitor or a proteasome inhibitor to suppress Nrf2 degradation effectively alleviated HSV-1 encephalitis. Together, our findings demonstrate the interaction between HSV-1 infection and ferroptosis and provide novel insights into the pathogenesis of HSV-1 encephalitis. IMPORTANCE Ferroptosis is a nonapoptotic form of programmed cell death that contributes to different neurological inflammatory diseases. However, whether HSV-1 induces ferroptosis in the CNS and the role of ferroptosis in viral pathogenesis remain unclear. In the current study, we demonstrate that HSV-1 infection induces ferroptosis, as Fe²⁺ overload, ROS accumulation, GSH depletion, lipid peroxidation, and mitochondrion shrinkage, all of which are hallmarks of ferroptosis, are observed in human cultured astrocytes, microglia cells, and murine brains infected with HSV-1. Moreover, HSV-1 infection enhances Keap1-dependent Nrf2 ubiquitination and degradation, which results in substantial reductions in the expression levels of antiferroptotic genes downstream of Nrf2, thereby disturbing cellular redox homeostasis and promoting ferroptosis. Furthermore, HSV-1-induced ferroptosis is tightly associated with the process of viral encephalitis in a mouse model, and the ferroptosis-activated upregulation of PTGS2 and PGE₂ plays an important role in HSV-1-caused inflammation and encephalitis. Importantly, the inhibition of ferroptosis by either a ferroptosis inhibitor or a proteasome inhibitor to suppress HSV-1-induced Nrf2 degradation effectively alleviates HSV-1-caused neuro-damage and inflammation in infected mice. Overall, our findings uncover the interaction between HSV-1 infection and ferroptosis, shed novel light on the physiological impacts of ferroptosis on the pathogenesis of HSV-1 infection and encephalitis, and provide a promising therapeutic strategy to treat this important infectious disease with a worldwide distribution.

Ferroptosis and tumor immunotherapy: A promising combination therapy for tumors

Low response rate and treatment resistance are frequent problems in the immunotherapy of tumors, resulting in the unsatisfactory therapeutic effects. Ferroptosis is a form of cell death characterized by the accumulation of lipid peroxides. In recent years, it has been found that ferroptosis may be related to the treatment of cancer. Various immune cells (including macrophages and CD8⁺ T cells) can induce ferroptosis of tumor cells, and synergistically enhance the anti-tumor immune effects. However, the mechanisms are different for each cell types. DAMP released in vitro by cancer cells undergoing ferroptosis lead to the maturation of dendritic cells, cross-induction of CD8⁺ T cells, IFN-γ production and M1 macrophage production. Thus, it activates the adaptability of the tumor microenvironment and forms positive feedback of the immune response. It suggests that induction of ferroptosis may contribute to reducing resistance of cancer immunotherapy and has great potential in cancer therapy. Further research into the link between ferroptosis and tumor immunotherapy may offer hope for those cancers that are difficult to treat. In this review, we focus on the role of ferroptosis in tumor immunotherapy, explore the role of ferroptosis in various immune cells, and discuss potential applications of ferroptosis in tumor immunotherapy.

Inhibitory effect and related mechanism of decitabine combined with gemcitabine on proliferation of NK/T cell lymphoma cells

Background: EBV-associated lymphoma is a neoplasm with a poor prognosis, highly aggressive, and progressive rapidly. There is no standard clinical treatment protocol. Decitabine and gemcitabine are known to have anticancer properties against cells of various cancer, respectively. However, the effect of the combination medication on NK/T cell lymphoma cells and potential mechanisms have not been thoroughly investigated. Methods: Human NK/T cell lymphoma cells NK92MI were treated with decitabine and gemcitabine alone or in combination. Experiments, including the Cell Counting Kit-8 and flow cytometry, were performed to investigate how the combination of decitabine and gemcitabine affects the biological behavior of NK92MI cells in vitro. mRNA sequencing, RT-PCR, and western blotting were used to detect changes in the related signal pathway, mRNA, and protein expressions. Results: Decitabine and gemcitabine significantly inhibited the viability and proliferation of NK92MI cells in a dose-dependent manner. The combination index was less than 1 after treating with two drugs, which was a significant synergistic effect. The decitabine concentration with the best synergistic effect was 4.046 µM, and the gemcitabine concentration was 0.005 µM. Flow cytometry showed that combining two drugs could significantly promote apoptosis and arrest the cell cycle at the S phase. In the combined DAC and GEM group, caspase3 protein levels were higher than in either group alone or the control group. The transcriptome sequence, KEGG, and PPI analysis showed that the differential genes after combined treatment were mainly enriched in signal pathways related to cell proliferation, adhesion, and migration compared with using alone and control groups. Based on the sequencing results, we further investigated the role of DAC and GEM in ferroptosis-related signaling molecules using RT-PCR and Western blot techniques. RT-PCR and western blotting showed that the expression levels of HMOX1 and EBV cleavage gene BRLF1 were higher in the group with combined DAC and GEM than in the group alone and the control group, while the protein and mRNA expression levels of SLC7A11 were lower than the others. In addition, the GPX4 protein expression level in the combination group was lower than in the drug-alone and control groups. In addition, the combination treatment increased the ROS level of NK92MI cells. Conclusion: Our current findings suggested that decitabine had an inhibitory effect on the proliferation of NK92MI cells when co-treated with gemcitabine. This combination may increase the expression of ferroptosis-related signaling molecules, thus inhibiting the proliferation of NK92MI cells. It also promoted apoptosis in NK/T cell lymphoma. For patients with NK/T cell lymphoma, this novel combination may provide clinical benefits.

When ferroptosis meets pathogenic infections

Apoptosis, necrosis, or autophagy are diverse types of regulated cell death (RCD), recognized as the strategies that host cells use to defend against pathogens such as viruses, bacteria, or fungi. Pathogens can induce or block different types of host cell RCD, promoting propagation or evading host immune surveillance. Ferroptosis is a newly identified RCD. Evidence has demonstrated how pathogens regulate ferroptosis to promote their replication, dissemination, and pathogenesis. However, the interaction between ferroptosis and pathogenic infections still needs to be completely elucidated. This review summarizes the advances in the interaction between pathogenic infections and host ferroptotic processes, focusing on the underlying mechanisms of how pathogens exploit ferroptosis, and discussing possible therapeutic measures against pathogen-associated diseases in a ferroptosis-dependent manner.