Tumor-infiltrating DCs suppress nucleic acid-mediated innate immune responses through interactions between the receptor TIM-3 and the alarmin HMGB1

Oral N-acetylcysteine ameliorates liver fibrosis and enhances regenerative responses in Mdr2 knockout mice

Cholangiopathies are poorly understood disorders with no effective therapy. The extrahepatic biliary tree phenotype is less studied compared to the intrahepatic biliary injury in both human disease and Mdr2-/- mice, the established cholestatic mouse model. This study aimed to characterize the extra hepatic biliary tree of Mdr2-/- mice at various ages and to determine if injury can be repaired with the antioxidant and glutathione precursor N-acetyl-L-Cysteine treatment (NAC). We characterized extra hepatic bile ducts (EHBD)s at various ages from 2 to 40 weeks old FVB/N and Mdr2-/- mice. We examined the therapeutic potential of local NAC ex vivo using EHBD explants at early and late stages of injury; and systematic therapy by in vivo oral administration for 3 weeks. EHBD and liver sections were assessed by histology and immunofluorescent stains. Serum liver enzyme activities were analyzed, and liver spatial protein expression analysis was performed. Mdr2-/- mice developed progressive EHBD injury, similar to extrahepatic PSC. NAC treatment of ex vivo EHBD explants led to improved duct morphology. In vivo, oral administration of NAC improved liver fibrosis, and decreased liver enzyme activities. Spatial protein analysis revealed cell-type specific differential response to NAC, collectively indicating a transition from pro-apoptotic into proliferative state. NAC treatment should be further investigated as a potential therapeutic option for human cholangiopathies.

The role of Tim-3 blockade in the tumor immune microenvironment beyond T cells

Numerous preclinical studies have demonstrated the inhibitory function of T cell immunoglobulin mucin domain-containing protein 3 (Tim-3) on T cells as an inhibitory receptor, leading to the clinical development of anti-Tim-3 blocking antibodies. However, recent studies have shown that Tim-3 is expressed not only on T cells but also on multiple cell types in the tumor microenvironment (TME), including dendritic cells (DCs), natural killer (NK) cells, macrophages, and tumor cells. Therefore, Tim-3 blockade in the immune microenvironment not only affect the function of T cells but also influence the functions of other cells. For example, Tim-3 blockade can enhance the ability of DCs to regulate innate and adaptive immunity. The role of Tim-3 blockade in NK cells function is controversial, as it can enhance the antitumor function of NK cells under certain conditions while having the opposite effect in other situations. Additionally, Tim-3 blockade can promote the reversal of macrophage polarization from the M2 phenotype to the M1 phenotype. Furthermore, Tim-3 blockade can inhibit tumor development by suppressing the proliferation and metastasis of tumor cells. In summary, increasing evidence has shown that Tim-3 in other cell types also plays a critical role in the efficacy of anti-Tim-3 therapy. Understanding the function of anti-Tim-3 therapy in non-T cells can help elucidate the diverse responses observed in clinical patients, leading to better development of relevant therapeutic strategies. This review aims to discuss the role of Tim-3 in the TME and emphasize the impact of Tim-3 blockade in the tumor immune microenvironment beyond T cells.

Reduced T and NK Cell Activity in Glioblastoma Patients Correlates with TIM-3 and BAT3 Dysregulation

Inhibitory receptors are critical for regulating immune cell function. In cancer, these receptors are often over-expressed on the cell surface of T and NK cells, leading to reduced anti-tumor activity. Here, through the analysis of 11 commonly studied checkpoint and inhibitory receptors, we discern that only HAVCR2 (TIM3) and ENTPD1 (CD39) display significantly greater gene expression in glioblastoma compared to normal brain and lower grade glioma. Cell surface TIM-3, but not ENTPD1, was also elevated on activated CD4+ and CD8+ T cells, as well as on NK cells from glioblastoma patients compared to healthy donor T and NK cells. A subsequent analysis of molecules known to co-ordinate TIM-3 function and regulation was performed, which revealed that BAT3 expression was significantly reduced in CD4+ and CD8+ T cells, as well as NK cells from glioblastoma patients compared to counterparts from healthy donors. These pro-inhibitory changes are also correlated with reduced levels of the activation marker CD69 and the pro-inflammatory cytokine IFNγ in CD4+ and CD8+ T cells, as well as NK cells from glioblastoma patients. Collectively, these data reveal that glioblastoma-mediated CD4+ and CD8+ T cell and NK cell suppression is due, at least in part, to dysregulated TIM-3 and BAT3 expression and the associated downstream immunoregulatory and dysfunctional effects.

Persistent Activation of the P2X7 Receptor Underlies Chronic Inflammation and Carcinogenic Changes in the Intestine

Aberrant signaling through damage-associated molecular patterns (DAMPs) has been linked to several health disorders, attracting considerable research interest over the last decade. Adenosine triphosphate (ATP), a key extracellular DAMP, activates the purinergic receptor P2X7, which acts as a danger sensor in immune cells and is implicated in distinct biological functions, including cell death, production of pro-inflammatory cytokines, and defense against microorganisms. In addition to driving inflammation mediated by immune and non-immune cells, the persistent release of endogenous DAMPs, including ATP, has been shown to result in epigenetic modifications. In intestinal diseases such as inflammatory bowel disease (IBD) and colorectal cancer (CRC), consequent amplification of the inflammatory response and the resulting epigenetic reprogramming may impact the development of pathological changes associated with specific disease phenotypes. P2X7 is overexpressed in the gut mucosa of patients with IBD, whereas the P2X7 blockade prevents the development of chemically induced experimental colitis. Recent data suggest a role for P2X7 in determining gut microbiota composition. Regulatory mechanisms downstream of the P2X7 receptor, combined with signals from dysbiotic microbiota, trigger intracellular signaling pathways and inflammasomes, intensify inflammation, and foster colitis-associated CRC development. Preliminary studies targeting the ATP-P2X7 pathway have shown favorable therapeutic effects in human IBD and experimental colitis.

Inhibitory immune checkpoints suppress the surveillance of senescent cells promoting their accumulation with aging and in age-related diseases

The accumulation of pro-inflammatory senescent cells within tissues is a common hallmark of the aging process and many age-related diseases. This modification has been called the senescence-associated secretory phenotype (SASP) and observed in cultured cells and in cells isolated from aged tissues. Currently, there is a debate whether the accumulation of senescent cells within tissues should be attributed to increased generation of senescent cells or to a defect in their elimination from aging tissues. Emerging studies have revealed that senescent cells display an increased expression of several inhibitory immune checkpoint ligands, especially those of the programmed cell death protein-1 (PD-1) ligand-1 (PD-L1) proteins. It is known that the PD-L1 ligands, especially those of cancer cells, target the PD-1 receptor of cytotoxic CD8+ T and natural killer (NK) cells disturbing their functions, e.g., evoking a decline in their cytotoxic activity and promoting their exhaustion and even apoptosis. An increase in the level of the PD-L1 protein in senescent cells was able to suppress their immune surveillance and inhibit their elimination by cytotoxic CD8+ T and NK cells. Senescent cells are known to express ligands for several inhibitory immune checkpoint receptors, i.e., PD-1, LILRB4, NKG2A, TIM-3, and SIRPα receptors. Here, I will briefly describe those pathways and examine whether these inhibitory checkpoints could be involved in the immune evasion of senescent cells with aging and age-related diseases. It seems plausible that an enhanced inhibitory checkpoint signaling can prevent the elimination of senescent cells from tissues and thus promote the aging process.

Igniting hope: Harnessing NLRP3 inflammasome-GSDMD-mediated pyroptosis for cancer immunotherapy

In the contemporary landscape of oncology, immunotherapy, represented by immune checkpoint blockade (ICB) therapy, stands out as a beacon of innovation in cancer treatment. Despite its promise, the therapy's progression is hindered by suboptimal clinical response rates. Addressing this challenge, the modulation of the NLRP3 inflammasome-GSDMD-mediated pyroptosis pathway holds promise as a means to augment the efficacy of immunotherapy. In the pathway, the NLRP3 inflammasome serves as a pivotal molecular sensor that responds to inflammatory stimuli within the organism. Its activation leads to the release of cytokines interleukin 1β and interleukin 18 through the cleavage of GSDMD, thereby forming membrane pores and potentially resulting in pyroptosis. This cascade of processes exerts a profound impact on tumor development and progression, with its function and expression exhibiting variability across different tumor types and developmental stages. Consequently, understanding the specific roles of the NLRP3 inflammasome and GSDMD-mediated pyroptosis in diverse tumors is imperative for comprehending tumorigenesis and crafting precise therapeutic strategies. This review aims to elucidate the structure and activation mechanisms of the NLRP3 inflammasome, as well as the induction mechanisms of GSDMD-mediated pyroptosis. Additionally, we provide a comprehensive overview of the involvement of this pathway in various cancer types and its applications in tumor immunotherapy, nanotherapy, and other fields. Emphasis is placed on the feasibility of leveraging this approach to enhance ICB therapy within the field of immunotherapy. Furthermore, we discuss the potential applications of this pathway in other immunotherapy methods, such as chimeric antigen receptor T-cell (CAR-T) therapy and tumor vaccines.

Novel insights into immune cells modulation of tumor resistance

Tumor resistance poses a significant challenge to effective cancer treatment, making it imperative to explore new therapeutic strategies. Recent studies have highlighted the profound involvement of immune cells in the development of tumor resistance. Within the tumor microenvironment, macrophages undergo polarization into the M2 phenotype, thus promoting the emergence of drug-resistant tumors. Neutrophils contribute to tumor resistance by forming extracellular traps. While T cells and natural killer (NK) cells exert their impact through direct cytotoxicity against tumor cells. Additionally, dendritic cells (DCs) have been implicated in preventing tumor drug resistance by stimulating T cell activation. In this review, we provide a comprehensive summary of the current knowledge regarding immune cell-mediated modulation of tumor resistance at the molecular level, with a particular focus on macrophages, neutrophils, DCs, T cells, and NK cells. The targeting of immune cell modulation exhibits considerable potential for addressing drug resistance, and an in-depth understanding of the molecular interactions between immune cells and tumor cells holds promise for the development of innovative therapies. Furthermore, we explore the clinical implications of these immune cells in the treatment of drug-resistant tumors. This review emphasizes the exploration of novel approaches that harness the functional capabilities of immune cells to effectively overcome drug-resistant tumors.

Multimodal Spatial Profiling Reveals Immune Suppression and Microenvironment Remodeling in Fallopian Tube Precursors to High-Grade Serous Ovarian Carcinoma

High-Grade Serous Ovarian Cancer (HGSOC) originates from fallopian tube (FT) precursors. However, the molecular changes that occur as precancerous lesions progress to HGSOC are not well understood. To address this, we integrated high-plex imaging and spatial transcriptomics to analyze human tissue samples at different stages of HGSOC development, including p53 signatures, serous tubal intraepithelial carcinomas (STIC), and invasive HGSOC. Our findings reveal immune modulating mechanisms within precursor epithelium, characterized by chromosomal instability, persistent interferon (IFN) signaling, and dysregulated innate and adaptive immunity. FT precursors display elevated expression of MHC-class I, including HLA-E, and IFN-stimulated genes, typically linked to later-stage tumorigenesis. These molecular alterations coincide with progressive shifts in the tumor microenvironment, transitioning from immune surveillance in early STICs to immune suppression in advanced STICs and cancer. These insights identify potential biomarkers and therapeutic targets for HGSOC interception and clarify the molecular transitions from precancer to cancer.

Immunometabolic characteristics of Dendritic Cells and its significant modulation by mitochondria-associated signaling in the tumor microenvironment influence cancer progression

Dendritic cells (DCs) mediated T-cell responses is critical to anti-tumor immunity. This study explores immunometabolic attributes of DC, emphasizing on mitochondrial association, in Tumor Microenvironment (TME) that regulate cancer progression. Conventional DC subtypes cross-present tumor-associated antigens to activate lymphocytes. However, plasmacytoid DCs participate in both pro- and anti-tumor signaling where mitochondrial reactive oxygen species (mtROS) play crucial role. CTLA-4, CD-47 and other surface-receptors of DC negatively regulates T-cell. Increased glycolysis-mediated mitochondrial citrate buildup and translocation to cytosol with augmented NADPH, enhances mitochondrial fatty acid synthesis fueling DCs. Different DC subtypes and stages, exhibit variable mitochondrial content, membrane potential, structural dynamics and bioenergetic metabolism regulated by various cytokine stimulation, e.g., GM-CSF, IL-4, etc. CD8α+ cDC1s augmented oxidative phosphorylation (OXPHOS) which diminishes at advance effector stages. Glutaminolysis in mitochondria supplement energy in DCs but production of kynurenine and other oncometabolites leads to immunosuppression. Mitochondria-associated DAMPs cause activation of cGAS-STING pathway and inflammasome oligomerization stimulating DC and T cells. In this study, through a comprehensive survey and critical analysis of the latest literature, the potential of DC metabolism for more effective tumor therapy is highlighted. This underscores the need for future research to explore specific therapeutic targets and potential drug candidates.

NK Cell Receptors in Anti-Tumor and Healthy Tissue Protection: Mechanisms and Therapeutic Advances

Natural Killer (NK) cells are integral to the innate immune system, renowned for their ability to target and eliminate cancer cells without the need for antigen presentation, sparing normal tissues. These cells are crucial in cancer immunosurveillance due to their diverse array of activating and inhibitory receptors that modulate their cytotoxic activity. However, the tumor microenvironment can suppress NK cell function through various mechanisms. Over recent decades, research has focused on overcoming these tumor escape mechanisms. Initially, efforts concentrated on enhancing T cell activity, leading to impressive results with immunotherapeutic approaches aimed at boosting T cell responses. Nevertheless, a substantial number of patients do not benefit from these treatments and continue to seek effective alternatives. In this context, NK cells present a promising avenue for developing new treatments, given their potent cytotoxic capabilities, safety profile, and activity against T cell-resistant tumors, such as those lacking HLA-I expression. Recent advancements in immunotherapy include strategies to restore and amplify NK cell activity through immune checkpoint inhibitors, cytokines, adoptive NK cell therapy, and CAR-NK cell technology. This review provides a comprehensive overview of NK cell receptors, the tumor escape mechanisms that hinder NK cell function, and the evolving field of NK cell-based cancer immunotherapy, highlighting ongoing efforts to develop more effective and targeted cancer treatment strategies.

Immune checkpoint inhibitors in infectious disease

Following success in cancer immunotherapy, immune checkpoint blockade is emerging as an exciting potential treatment for some infectious diseases, specifically two chronic viral infections, HIV and hepatitis B. Here, we will discuss the function of immune checkpoints, their role in infectious disease pathology, and the ability of immune checkpoint blockade to reinvigorate the immune response. We focus on blockade of programmed cell death 1 (PD-1) to induce durable immune-mediated control of HIV, given that anti-PD-1 can restore function to exhausted HIV-specific T cells and also reverse HIV latency, a long-lived form of viral infection. We highlight several key studies and future directions of research in relation to anti-PD-1 and HIV persistence from our group, including the impact of immune checkpoint blockade on the establishment (AIDS, 2018, 32, 1491), maintenance (PLoS Pathog, 2016, 12, e1005761; J Infect Dis, 2017, 215, 911; Cell Rep Med, 2022, 3, 100766) and reversal of HIV latency (Nat Commun, 2019, 10, 814; J Immunol, 2020, 204, 1242), enhancement of HIV-specific T cell function (J Immunol, 2022, 208, 54; iScience, 2023, 26, 108165), and investigating the effects of anti-PD-1 and anti-CTLA-4 in vivo in people with HIV on ART with cancer (Sci Transl Med, 2022, 14, eabl3836; AIDS, 2021, 35, 1631; Clin Infect Dis, 2021, 73, e1973). Our future work will focus on the impact of anti-PD-1 in vivo in people with HIV on ART without cancer and potential combinations of anti-PD-1 with other interventions, including therapeutic vaccines or antibodies and less toxic immune checkpoint blockers.

TIM-3 on myeloid cells promotes pulmonary inflammation through increased production of galectin-3

T cell immunoglobulin and mucin-containing molecule 3 (TIM-3) exhibits unique, cell type- and context-dependent characteristics and functions. Here, we report that TIM-3 on myeloid cells plays essential roles in modulating lung inflammation. We found that myeloid cell-specific TIM-3 knock-in (FSF-TIM3/LysM-Cre+) mice have lower body weight and shorter lifespan than WT mice. Intriguingly, the lungs of FSF-TIM3/LysM-Cre+ mice display excessive inflammation and features of disease-associated pathology. We further revealed that galectin-3 levels are notably elevated in TIM-3-overexpressing lung-derived myeloid cells. Furthermore, both TIM-3 blockade and GB1107, a galectin-3 inhibitor, ameliorated lung inflammation in FSF-TIM3/LysM-Cre+/- mice. Using an LPS-induced lung inflammation model with myeloid cell-specific TIM-3 knock-out mice, we demonstrated the association of TIM-3 with both lung inflammation and galectin-3. Collectively, our findings suggest that myeloid TIM-3 is an important regulator in the lungs and that modulation of TIM-3 and galectin-3 could offer therapeutic benefits for inflammation-associated lung diseases.

Dysfunction of dendritic cells in tumor microenvironment and immunotherapy

Dendritic cells (DCs) comprise diverse cell populations that play critical roles in antigen presentation and triggering immune responses in the body. However, several factors impair the immune function of DCs and may promote immune evasion in cancer. Understanding the mechanism of DC dysfunction and the diverse functions of heterogeneous DCs in the tumor microenvironment (TME) is critical for designing effective strategies for cancer immunotherapy. Clinical applications targeting DCs summarized in this report aim to improve immune infiltration and enhance the biological function of DCs to modulate the TME to prevent cancer cells from evading the immune system. Herein, factors in the TME that induce DC dysfunction, such as cytokines, hypoxic environment, tumor exosomes and metabolites, and co-inhibitory molecules, have been described. Furthermore, several key signaling pathways involved in DC dysfunction and signal-relevant drugs evaluated in clinical trials were identified. Finally, this review provides an overview of current clinical immunotherapies targeting DCs, especially therapies with proven clinical outcomes, and explores future developments in DC immunotherapies.

Advances in immunotherapy for breast cancer and feline mammary carcinoma: From molecular basis to novel therapeutic targets

The role of inflammation in cancer is a topic that has been investigated for many years. As established, inflammation emerges as a defining characteristic of cancer, presenting itself as a compelling target for therapeutic interventions in the realm of oncology. Controlling the tumor microenvironment (TME) has gained paramount significance, modifying not only the effectiveness of immunotherapy but also modulating the outcomes and prognoses of standard chemotherapy and other anticancer treatments. Immunotherapy has surfaced as a central focus within the domain of tumor treatments, using immune checkpoint inhibitors as cancer therapy. Immune checkpoints and their influence on the tumor microenvironment dynamic are presently under investigation, aiming to ascertain their viability as therapeutic interventions across several cancer types. Cancer presents a significant challenge in humans and cats, where female breast cancer ranks as the most prevalent malignancy and feline mammary carcinoma stands as the third most frequent. This review seeks to summarize the data about the immune checkpoints cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), lymphocyte activation gene-3 (LAG-3), programmed cell death protein-1 (PD-1), V-domain Ig suppressor of T cell activation (VISTA), and T-cell immunoglobulin and mucin domain 3 (TIM-3) respective ongoing investigations as prospective targets for therapy for human breast cancer, while also outlining findings from studies reported on feline mammary carcinoma (FMC), strengthening the rationale for employing FMC as a representative model in the exploration of human breast cancer.

OMIP-105: A 30-color full-spectrum flow cytometry panel to characterize the immune cell landscape in spleen and tumor within a syngeneic MC-38 murine colon carcinoma model

This panel was designed to characterize the immune cell landscape in the mouse tumor microenvironment as well as mouse lymphoid tissues (e.g., spleen). As an example, using the MC-38 mouse syngeneic tumor model, we demonstrated that we could measure the frequency and characterize the functional status of CD4 T cells, CD8 T cells, regulatory T cells, NK cells, B cells, macrophages, granulocytes, monocytes, and dendritic cells. This panel is especially useful for understanding the immune landscape in "cold" preclinical tumor models with very low immune cell infiltration and for investigating how therapeutic treatments may modulate the immune landscape.

Emerging role of immunogenic cell death in cancer immunotherapy: Advancing next-generation CAR-T cell immunotherapy by combination

Immunogenic cell death (ICD) is a stress-driven form of regulated cell death (RCD) in which dying tumor cells' specific signaling pathways are activated to release damage-associated molecular patterns (DAMPs), leading to the robust anti-tumor immune response as well as a reversal of the tumor immune microenvironment from "cold" to "hot". Chimeric antigen receptor (CAR)-T cell therapy, as a landmark in anti-tumor immunotherapy, plays a formidable role in hematologic malignancies but falls short in solid tumors. The Gordian knot of CAR-T cells for solid tumors includes but is not limited to, tumor antigen heterogeneity or absence, physical and immune barriers of tumors. The combination of ICD induction therapy and CAR-T cell immunotherapy is expected to promote the intensive use of CAR-T cell in solid tumors. In this review, we summarize the characteristics of ICD, stress-responsive mechanism, and the synergistic effect of various ICD-based therapies with CAR-T cells to effectively improve anti-tumor capacity.

Immune checkpoint inhibitors and SARS-CoV2 infection

Infection with severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) triggers coronavirus disease 2019 (COVID-19), which predominantly targets the respiratory tract. SARS-CoV-2 infection, especially severe COVID-19, is associated with dysregulated immune responses against the virus, including exaggerated inflammatory responses known as the cytokine storm, together with lymphocyte and NK cell dysfunction known as immune cell exhaustion. Overexpression of negative immune checkpoints such as PD-1 and CTLA-4 plays a considerable role in the dysfunction of immune cells upon SARS-CoV-2 infection. Blockade of these checkpoints has been suggested to improve the clinical outcome of COVID-19 patients by promoting potent immune responses against the virus. In the current review, we provide an overview of the potential of checkpoint inhibitors to induce potent immune responses against SARS-CoV-2 and improving the clinical outcome of severe COVID-19 patients.

Combination of locoregional radiotherapy with a TIM-3 aptamer improves survival in diffuse midline glioma models

Pediatric diffuse midline gliomas (DMG) with altered H3-K27M are aggressive brain tumors that arise during childhood. Despite advances in genomic knowledge and the significant number of clinical trials testing new targeted therapies, patient outcomes are still poor. Immune checkpoint blockades with small molecules, such as aptamers, are opening new therapeutic options that represent hope for this orphan disease. Here, we demonstrated that a TIM-3 aptamer (TIM-3 Apt) as monotherapy increased the immune infiltration and elicited a strong specific immune response with a tendency to improve the overall survival of treated DMG-bearing mice. Importantly, combining TIM-3 Apt with radiotherapy increased the overall median survival and led to long-term survivor mice in 2 pediatric DMG orthotopic murine models. Interestingly, TIM-3 Apt administration increased the number of myeloid populations and the proinflammatory CD8-to-Tregs ratios in the tumor microenvironment as compared with nontreated groups after radiotherapy. Importantly, the depletion of T cells led to a major loss of the therapeutic effect achieved by the combination. This work uncovers TIM-3 targeting as an immunotherapy approach to improve the radiotherapy outcome in DMGs and offers a strong foundation for propelling a phase I clinical trial using radiotherapy and TIM-3 blockade combination as a treatment for these tumors.

Role of TIM-3 in ovarian cancer: the forsaken cop or a new noble

T cell immunoglobulin and mucin domain-3 (TIM-3), a crucial immune checkpoint following PD1 and CTLA4, is widely found in several immune cells. Nonetheless, its performance in recent clinical trials appears disappointing. Ovarian cancer (OC), a malignant tumor with a high mortality rate in gynecology, faces significant hurdles in immunotherapy. The broad presence of TIM-3 offers a new opportunity for immunotherapy in OC. This study reviews the role of TIM-3 in OC and assesses its potential as a target for immunotherapy. The regulatory effects of TIM-3 on the immune microenvironment in OC are discussed, with a focus on preclinical studies that demonstrate TIM-3's modulation of various immune cells in OC. Additionally, the potential therapeutic advantages and challenges of targeting TIM-3 in OC are examined.

Immunosuppressive tumor microenvironment in the progression, metastasis, and therapy of hepatocellular carcinoma: from bench to bedside

Hepatocellular carcinoma (HCC) is a highly heterogeneous malignancy with high incidence, recurrence, and metastasis rates. The emergence of immunotherapy has improved the treatment of advanced HCC, but problems such as drug resistance and immune-related adverse events still exist in clinical practice. The immunosuppressive tumor microenvironment (TME) of HCC restricts the efficacy of immunotherapy and is essential for HCC progression and metastasis. Therefore, it is necessary to elucidate the mechanisms behind immunosuppressive TME to develop and apply immunotherapy. This review systematically summarizes the pathogenesis of HCC, the formation of the highly heterogeneous TME, and the mechanisms by which the immunosuppressive TME accelerates HCC progression and metastasis. We also review the status of HCC immunotherapy and further discuss the existing challenges and potential therapeutic strategies targeting immunosuppressive TME. We hope to inspire optimizing and innovating immunotherapeutic strategies by comprehensively understanding the structure and function of immunosuppressive TME in HCC.

Unravelling the potential of TIM-3 gene polymorphism in allogeneic hematopoietic stem cell transplantation - a preliminary study

BACKGROUND

T-cell immunoglobulin and mucin-domain containing-3 (TIM-3) molecule is a key regulator of the immune response by exerting an inhibitory effect on various types of immune cells. Understanding the role of TIM-3 in hematopoietic stem cell transplantation (HSCT) may improve transplant outcomes. Our study evaluated the potential association between TIM-3 polymorphisms, namely rs1036199 (A > C) or rs10515746 (C > A), changes which are located in exon 3 and the promoter region of the TIM-3 gene, and post-HSCT outcomes.

METHODS

One-hundred and twenty allogeneic HSCT patients and their respective donors were enrolled and genotyped for TIM-3 single nucleotide polymorphisms (SNPs) using real-time PCR with TaqMan assays.

RESULTS

We found that the presence of the rare alleles and heterozygous genotypes of studied SNP in recipients tended to protect against or increase the risk for acute graft-versus-host disease (aGvHD). For the rs1036199 polymorphism, recipients with the AC heterozygous genotype (p = 0.0287) or carrying the rarer C allele (p = 0.0334) showed a lower frequency of aGvHD development along all I-IV grades. A similar association was detected for the rs10515746 polymorphism as recipients with the CA genotype (p = 0.0095) or the recessive A allele (p = 0.0117) less frequently developed aGvHD. Furthermore, the rarer A allele of rs10515746 SNP was also associated with a prolonged aGvHD-free survival (p = 0.0424). Cytomegalovirus (CMV) infection was more common in patients transplanted with TIM-3 rs10515746 mismatched donors (p = 0.0229) and this association was also found to be independent of HLA incompatibility and pre-transplant CMV-IgG status. Multivariate analyses confirmed the role of these recessive alleles and donor-recipient TIM-3 incompatibility as an independent factor in aGvHD and CMV development.

CONCLUSIONS

Polymorphism of TIM-3 molecule may affect the immune response in HSCT patients. The recessive alleles of rs1036199 and rs10515746 SNPs decreased the risk of developing aGvHD. TIM-3 donor-recipient genetic matching may also affect the risk of post-transplant CMV infection, indicating the potential value of genetic profiling in optimizing transplant strategies.

Deciphering the roles of the HMGB family in cancer: Insights from subcellular localization dynamics

The high-mobility group box (HMGB) family consists of four DNA-binding proteins that regulate chromatin structure and function. In addition to their intracellular functions, recent studies have revealed their involvement as extracellular damage-associated molecular patterns (DAMPs), contributing to immune responses and tumor development. The HMGB family promotes tumorigenesis by modulating multiple processes including proliferation, metabolic reprogramming, metastasis, immune evasion, and drug resistance. Due to the predominant focus on HMGB1 in the literature, little is known about the remaining members of this family. This review summarizes the structural, distributional, as well as functional similarities and distinctions among members of the HMGB family, followed by a comprehensive exploration of their roles in tumor development. We emphasize the distributional and functional hierarchy of the HMGB family at both the organizational and subcellular levels, with a focus on their relationship with the tumor immune microenvironment (TIME), aiming to prospect potential strategies for anticancer therapy.

G protein-coupled receptor-mediated signaling of immunomodulation in tumor progression

G protein-coupled receptors (GPCRs) are essential contributors to tumor growth and metastasis due to their roles in immune cell regulation. Therefore, GPCRs are potential targets for cancer immunotherapy. Here, we discuss the current understanding of the roles of GPCRs and their signaling pathways in tumor progression from an immunocellular perspective. Additionally, we focus on the roles of GPCRs in regulating immune checkpoint proteins involved in immune evasion. Finally, we review the progress of clinical trials of GPCR-targeted drugs for cancer treatment, which may be combined with immunotherapy to improve treatment efficacy. This expanded understanding of the role of GPCRs may shed light on the mechanisms underlying tumor progression and provide a novel perspective on cancer immunotherapy.

The Roles of T cells in Immune Checkpoint Inhibitor-Induced Arthritis

Immune checkpoint inhibitor (ICI) therapy, a novel anti-tumor strategy, can specifically eliminate tumors by activating the immune system and inhibiting tumor immune escape. However, ICI therapy can lead to notable negative outcomes known as immune-related adverse events (irAEs). ICI-induced arthritis, also known as ICI arthritis, stands as the prevailing form of irAEs. The purpose of this review is to highlight the crucial functions of T cells in the progression of ICI arthritis. Under the influence of different signaling molecules, T cells could gather in large numbers within the synovial membrane of joints, releasing inflammatory substances and enzymes that harm healthy tissues, ultimately causing ICI arthritis. Moreover, considering the functions of T cells in triggering ICI arthritis, this review suggests several treatments to prevent ICI arthritis, including inhibiting the overstimulation of T cells at the synovial sac of joints, enhancing the precision of ICI medications, and directing ICI drugs specifically towards tumor tissues instead of joints. Collectively, T lymphocytes play a vital role in the onset of ICI arthritis, offering a hopeful perspective on treating ICI arthritis through the specific targeting of T cells within the affected joints.

Impact of LAG-3/FGL1 pathway on immune evasive contexture and clinical outcomes in advanced urothelial carcinoma

BACKGROUND

Anti-programmed death-1 (PD-1)/anti-PD-ligand-1 (PD-L1) pathway inhibition is a standard regimen for advanced urothelial carcinoma (UC); however, its limited efficacy has been reflected in reported medium response rates. This study explored the role of next-generation coinhibitory receptors (IRs; lymphocyte activation gene 3 (LAG-3), T-cell immunoglobulin and mucin domain 3 (TIM-3), and T-cell immunoreceptor with Ig and ITIM domains (TIGIT)) and their ligands (LGs) in the response to PD-(L)1 blockade therapy and the oncological outcomes in patients with UC.

METHODS

We investigated metastatic UC cases who underwent PD-(L)1 therapy (cohort 1: n=348, cohort 2: n=89, and cohort 4: n=29) or advanced UC cases involving surgery (cohort 3: n=293 and cohort 5: n=90). We assessed the mRNA expression profiles and corresponding clinical information regarding IRs and LGs using cohorts 1, 2, and 3. Additionally, we elucidated the spatial features of these targeted markers using multiplex immunohistochemistry (mIHC) on formalin-fixed paraffin-embedded samples from cohorts 4 and 5. Survival, differential expressed gene, and Gene Set Enrichment analyses were performed. For mIHC, quantitative analyses were also performed to correlate immune and tumor cell densities with patient survival.

RESULTS

LAG-3 expression was strongly associated with the responsiveness of PD-(L)1 blockade compared with the expression of TIM-3 and TIGIT. In tumors with high LAG-3 levels, the increased expression of fibrinogen-like protein 1 (FGL1) had a significantly negative effect on the response to PD-(L)1 blockade and overall survival. Moreover, high FGL1 levels were associated with elevated CD4+ regulatory T-cell gene signatures and the upregulation of CD39 and neuropilin-1, with both indicating CD8+ T-cell exhaustion. mIHC analyses revealed that patients with stromal CD8+LAG-3+cellshigh-tumor FGL1+cellshigh exhibited a significant negative correlation with survival rates compared with those with stromal CD8+LAG-3+cellshigh-tumor FGL1+cellslow.

CONCLUSIONS

LAG-3 expression and high FGL1 coexpression are important predictive factors of adverse oncological outcomes related to the presence of immunosuppressive contextures. These findings are hypothesis-generating, warranting further mechanistic and clinical studies aimed to evaluate LAG-3/FGL1 blockade in UC.

Non-Coding RNA in Tumor Cells and Tumor-Associated Myeloid Cells-Function and Therapeutic Potential

The RNA world is wide, and besides mRNA, there is a variety of other RNA types, such as non-coding (nc)RNAs, which harbor various intracellular regulatory functions. This review focuses on small interfering (si)RNA and micro (mi)RNA, which form a complex network regulating mRNA translation and, consequently, gene expression. In fact, these RNAs are critically involved in the function and phenotype of all cells in the human body, including malignant cells. In cancer, the two main targets for therapy are dysregulated cancer cells and dysfunctional immune cells. To exploit the potential of mi- or siRNA therapeutics in cancer therapy, a profound understanding of the regulatory mechanisms of RNAs and following targeted intervention is needed to re-program cancer cells and immune cell functions in vivo. The first part focuses on the function of less well-known RNAs, including siRNA and miRNA, and presents RNA-based technologies. In the second part, the therapeutic potential of these technologies in treating cancer is discussed, with particular attention on manipulating tumor-associated immune cells, especially tumor-associated myeloid cells.

Inhibitory Checkpoint Receptor TIM-3 as a Regulator of the Functional Activity of Dendritic Cells

T-cell immunoglobulin and mucin domain 3 (TIM-3) belongs to the group of inhibitory checkpoint receptors and has traditionally been of interest in terms of its expression on activated CD4+ and CD8+ T cells. The treatment with TIM-3 inhibitors is considered as a promising strategy in cancer immunotherapy. The review focuses on new data on the expression of TIM-3 on dendritic cells (DCs) that play a key role in initiating the antigen-specific immune response and inducing effector CD8+ T cells. The main hypothesis is that TIM-3 is suggested to act as a negative regulator of DCs. Further studies on TIM-3-mediated DC regulation will improve the effectiveness of current strategies in the treatment of cancer using DCs and checkpoint molecule inhibitors, where the main targets can be not only T cells, but also TIM-3-expressing DCs.

Dismantlable Coronated Nanoparticles for Coupling the Induction and Perception of Immunogenic Cell Death

Therapy-induced immunogenic cell death (ICD) can initiate both innate and adaptive immune responses for amplified anti-tumor efficacy. However, dying cell-released ICD signals are prone to being sequestered by the TIM-3 receptors on dendritic cell (DC) surfaces, preventing immune surveillance. Herein, dismantlable coronated nanoparticles (NPs) are fabricated as a type of spatiotemporally controlled nanocarriers for coupling tumor cell-mediated ICD induction to DC-mediated immune sensing. These NPs are loaded with an ICD inducer, mitoxantrone (MTO), and wrapped by a redox-labile anti-TIM-3 (αTIM-3) antibody corona, forming a separable core-shell structure. The antibody corona disintegrates under high levels of extracellular reactive oxygen species in the tumor microenvironment, exposing the MTO-loaded NP core for ICD induction and releasing functional αTIM-3 molecules for DC sensitization. Systemic administration of the coronated NPs augments DC maturation, promotes cytotoxic T cell recruitment, enhances tumor susceptibility to immune checkpoint blockade, and prevents the side effects of MTO. This study develops a promising nanoplatform to unleash the potential of host immunity in cancer therapy.

Porcine TLR8 signaling and its anti-infection function are disturbed by immune checkpoint receptor TIM-3 via inhibition of P13K-AKT pathway

Toll-like receptor 8 (TLR8), an important innate immune receptor recognizing single stranded RNA and the antiviral imidazoquinoline compounds, can activate intracellular signaling pathway and produce an inflammatory response to kill and eliminate pathogens. However, the molecular regulation mechanisms of TLR8 signaling and its anti-infection activity are not fully elucidated. Our previous transcriptome analysis of porcine TLR8 (pTLR8) signaling suggested the immune checkpoint receptor TIM-3 as the potential regulator for pTLR8. Here we investigated TIM-3 in the regulation of pTLR8 signaling and its anti-infection activity. Our results showed that porcine TIM-3 is upregulated by pTLR8 signaling and TIM-3 inhibits pTLR8 signaling activity in a negative feedback way. Accordingly, TIM-3 disturbs pTLR8 mediated anti-bacterial and anti-viral activity. Mechanistically, TIM-3 suppresses PI3K-AKT pathway by inhibiting the TLR8-PI3K p85 interaction and subsequent AKT phosphorylation which is essential for TLR8 signaling and anti-infection activity. Therefore, our study reveals new insights into innate immune TLR8 signaling and its anti-infection function.

Development of pharmacological immunoregulatory anti-cancer therapeutics: current mechanistic studies and clinical opportunities

Immunotherapy represented by anti-PD-(L)1 and anti-CTLA-4 inhibitors has revolutionized cancer treatment, but challenges related to resistance and toxicity still remain. Due to the advancement of immuno-oncology, an increasing number of novel immunoregulatory targets and mechanisms are being revealed, with relevant therapies promising to improve clinical immunotherapy in the foreseeable future. Therefore, comprehending the larger picture is important. In this review, we analyze and summarize the current landscape of preclinical and translational mechanistic research, drug development, and clinical trials that brought about next-generation pharmacological immunoregulatory anti-cancer agents and drug candidates beyond classical immune checkpoint inhibitors. Along with further clarification of cancer immunobiology and advances in antibody engineering, agents targeting additional inhibitory immune checkpoints, including LAG-3, TIM-3, TIGIT, CD47, and B7 family members are becoming an important part of cancer immunotherapy research and discovery, as are structurally and functionally optimized novel anti-PD-(L)1 and anti-CTLA-4 agents and agonists of co-stimulatory molecules of T cells. Exemplified by bispecific T cell engagers, newly emerging bi-specific and multi-specific antibodies targeting immunoregulatory molecules can provide considerable clinical benefits. Next-generation agents also include immune epigenetic drugs and cytokine-based therapeutics. Cell therapies, cancer vaccines, and oncolytic viruses are not covered in this review. This comprehensive review might aid in further development and the fastest possible clinical adoption of effective immuno-oncology modalities for the benefit of patients.

DNA sensing of dendritic cells in cancer immunotherapy

Dendritic cells (DCs) are involved in the initiation and maintenance of immune responses against malignant cells by recognizing conserved pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) through pattern recognition receptors (PRRs). According to recent studies, tumor cell-derived DNA molecules act as DAMPs and are recognized by DNA sensors in DCs. Once identified by sensors in DCs, these DNA molecules trigger multiple signaling cascades to promote various cytokines secretion, including type I IFN, and then to induce DCs mediated antitumor immunity. As one of the potential attractive strategies for cancer therapy, various agonists targeting DNA sensors are extensively explored including the combination with other cancer immunotherapies or the direct usage as major components of cancer vaccines. Moreover, this review highlights different mechanisms through which tumor-derived DNA initiates DCs activation and the mechanisms through which the tumor microenvironment regulates DNA sensing of DCs to promote tumor immune escape. The contributions of chemotherapy, radiotherapy, and checkpoint inhibitors in tumor therapy to the DNA sensing of DCs are also discussed. Finally, recent clinical progress in tumor therapy utilizing agonist-targeted DNA sensors is summarized. Indeed, understanding more about DNA sensing in DCs will help to understand more about tumor immunotherapy and improve the efficacy of DC-targeted treatment in cancer.

Advancements in the research of immune checkpoint inhibitors for the treatment of advanced esophageal squamous cell carcinoma

Esophageal cancer (EC) has a high mortality rate and poor prognosis. Most patients are diagnosed at an advanced stage or with distant metastasis, making surgery impossible. Traditional curative radiotherapy and chemotherapy have limited efficacy. In recent years, with the development of clinical trials, immune checkpoint inhibitors (ICIs) have shown promising results in treating advanced and metastatic esophageal squamous cell carcinoma (ESCC) patients. ICIs have gradually become a primary therapeutic approach for EC. This review summarizes and provides an overview of the current research status and progress of ICIs in the treatment of advanced ESCC patients.

TIM-3 Expression on Dendritic Cells in Colorectal Cancer

TIM-3 was originally identified as a negative regulator of helper T cells and is expressed on dendritic cells (DCs). Since the inhibition of TIM-3 on DCs has been suggested to enhance T cell-mediated anti-tumor immunity, we examined its expression on DCs within the tumor microenvironment (TME) in colorectal cancer (CRC) using transcriptomic data from a public database (n = 592) and immunohistochemical evaluations from our cohorts of CRC (n = 115). The expression of TIM-3 on DCs in vitro was examined by flow cytometry, while the expression of its related molecules, cGAS and STING, on immature and mature DCs was assessed by Western blotting. The expression of HAVCR2 (TIM-3) was strongly associated with the infiltration of DCs within the TME of CRC. Immunohistochemical staining of clinical tissue samples revealed that tumor-infiltrating DCs expressed TIM-3; however, their number at the tumor-invasive front significantly decreased with stage progression. TIM-3 expression was higher on immature DCs than on mature DCs from several different donors (n = 6). Western blot analyses showed that the expression of STING was higher on mature DCs than on immature DCs, which was opposite to that of TIM-3. We demonstrated that TIM-3 was highly expressed on tumor-infiltrating DCs of CRC and that its expression was higher on immature DCs than on mature DCs.

Research progress on morphology and mechanism of programmed cell death

Programmed cell death (PCD) is a basic process of life that is closely related to the growth, development, aging and disease of organisms and is one of the hotspots of life science research today. PCD is a kind of genetic control, autonomous and orderly important cell death that involves the activation, expression, and regulation of a series of genes. In recent years, with the deepening of research in this field, new mechanisms of multiple PCD pathways have been revealed. This article reviews and summarizes the multiple PCD pathways that have been discovered, analyses and compares the morphological characteristics and biomarkers of different types of PCD, and briefly discusses the role of various types of PCD in the diagnosis and treatment of different diseases, especially malignant tumors.

HMGB1 Expression Levels Correlate with Response to Immunotherapy in Non-Small Cell Lung Cancer

Purpose

High-mobility group box 1 protein (HMGB1) is subject to exportin 1 (XPO1)-dependent nuclear export, and it is involved in functions implicated in resistance to immunotherapy. We investigated whether HMGB1 mRNA expression was associated with response to immune checkpoint inhibitors (ICI) in non-small cell lung cancer (NSCLC).

Patients and Methods

RNA was isolated from pretreatment biopsies of patients with advanced NSCLC treated with ICI. Gene expression analysis of several genes, including HMGB1, was conducted using the NanoString Counter analysis system (PanCancer Immune Profiling Panel). Western blotting analysis and cell viability assays in EGFR and KRAS mutant cell lines were carried out. Evaluation of the antitumoral effect of ICI in combination with XPO1 blocker (selinexor) and trametinib was determined in a murine Lewis lung carcinoma model.

Results

HMGB1 mRNA levels in NSCLC patients treated with ICI correlated with progression-free survival (PFS) (median PFS 9.0 versus 18.0 months, P=0.008, hazard ratio=0.30 in high versus low HMGB1). After TNF-α stimulation, HMGB1 accumulates in the cytoplasm of PC9 cells, but this accumulation can be prevented by using selinexor or antiretroviral drugs. Erlotinib or osimertinib with selinexor in EGFR-mutant cells and trametinib plus selinexor in KRAS mutant abolish tumor cell proliferation. Selinexor with a PD-1 inhibitor with or without trametinib abrogates the tumor growth in the murine Lewis lung cancer model.

Conclusion

An in-depth exploration of the functions of HMGB1 mRNA and protein is expected to uncover new potential targets and provide a basis for treating metastatic NSCLC in combination with ICI.

The mechanism of high mobility group box-1 protein and its bidirectional regulation in tumors

High-mobility group box-1 protein (HMGB1) is a nonhistone chromatin-related protein widely found in eukaryotic cells. It is involved in the transcription, replication, and repair of DNA to maintain nuclear homeostasis. It participates in cell growth, differentiation, and signal transduction. Recent studies showed that HMGB1 has a bidirectional regulatory effect on tumors by regulating TLR4/MYD88/NF-κB and RAGE/AMPK/mTOR signaling pathways. On the one hand, it is highly expressed in a variety of tumors, promoting tumor proliferation and invasion, while on the other hand, it induces autophagy and apoptosis of tumor cells and stimulates tumor-infiltrating lymphocytes to produce an anti-tumor immune response. At present, HMGB1 could be used as a target to regulate the drug resistance and prognostication in cancer. Clinical applications of HMGB1 in cancer need further in-depth studies.

Tumor-necrosis factor α-rich environment alters type-I interferon response to viral stimuli in patients with juvenile idiopathic arthritis by altering myeloid dendritic cell phenotype

The balance between the tumor-necrosis factor α (TNFα) and type-I interferon (T1IFN) pathways is crucial for proper immune function. Dysregulation of either pathway can contribute to autoimmune diseases development. Even though TNFα blockade has shown promising results in various autoimmune diseases, the effect on the balance between TNFα and T1IFN is elusive. We used targeted anti-TNFα therapies in juvenile idiopathic arthritis (JIA) as an experimental approach to study the cross-regulation between TNFα and type-I IFN. We found that TNFα-rich environment affected viral defense through the attenuation of T1IFN responses and affected the phenotype and distribution of myeloid dendritic cells, which are engaged in early viral infections. Anti-TNFα therapy normalized the observed deviations in JIA patients. We hypothesize that the inadequate immune response caused by a high TNFα environment could be projected to more frequent or lengthy viral infections and possibly play a role in the process of JIA disease development.

Current Landscape of Cancer Immunotherapy: Harnessing the Immune Arsenal to Overcome Immune Evasion

Cancer immune evasion represents a leading hallmark of cancer, posing a significant obstacle to the development of successful anticancer therapies. However, the landscape of cancer treatment has significantly evolved, transitioning into the era of immunotherapy from conventional methods such as surgical resection, radiotherapy, chemotherapy, and targeted drug therapy. Immunotherapy has emerged as a pivotal component in cancer treatment, harnessing the body's immune system to combat cancer and offering improved prognostic outcomes for numerous patients. The remarkable success of immunotherapy has spurred significant efforts to enhance the clinical efficacy of existing agents and strategies. Several immunotherapeutic approaches have received approval for targeted cancer treatments, while others are currently in preclinical and clinical trials. This review explores recent progress in unraveling the mechanisms of cancer immune evasion and evaluates the clinical effectiveness of diverse immunotherapy strategies, including cancer vaccines, adoptive cell therapy, and antibody-based treatments. It encompasses both established treatments and those currently under investigation, providing a comprehensive overview of efforts to combat cancer through immunological approaches. Additionally, the article emphasizes the current developments, limitations, and challenges in cancer immunotherapy. Furthermore, by integrating analyses of cancer immunotherapy resistance mechanisms and exploring combination strategies and personalized approaches, it offers valuable insights crucial for the development of novel anticancer immunotherapeutic strategies.

Unleashing the power of immune checkpoints: Post-translational modification of novel molecules and clinical applications

Immune checkpoint molecules play a pivotal role in the initiation, regulation, and termination of immune responses. Tumor cells exploit these checkpoints to dampen immune cell function, facilitating immune evasion. Clinical interventions target this mechanism by obstructing the binding of immune checkpoints to their ligands, thereby restoring the anti-tumor capabilities of immune cells. Notably, therapies centered on immune checkpoint inhibitors, particularly PD-1/PD-L1 and CTLA-4 blocking antibodies, have demonstrated significant clinical promise. However, a considerable portion of patients still encounter suboptimal efficacy and develop resistance. Recent years have witnessed an exponential surge in preclinical and clinical trials investigating novel immune checkpoint molecules such as TIM3, LAG3, TIGIT, NKG2D, and CD47, along with their respective ligands. The processes governing immune checkpoint molecules, from their synthesis to transmembrane deployment, interaction with ligands, and eventual degradation, are intricately tied to post-translational modifications. These modifications encompass glycosylation, phosphorylation, ubiquitination, neddylation, SUMOylation, palmitoylation, and ectodomain shedding. This discussion proceeds to provide a concise overview of the structural characteristics of several novel immune checkpoints and their ligands. Additionally, it outlines the regulatory mechanisms governed by post-translational modifications, offering insights into their potential clinical applications in immune checkpoint blockade.

β-Catenin in Dendritic Cells Negatively Regulates CD8 T Cell Immune Responses through the Immune Checkpoint Molecule Tim-3

Recent studies have demonstrated that β-catenin in dendritic cells (DCs) serves as a key mediator in promoting both CD4 and CD8 T cell tolerance, although the mechanisms underlying how β-catenin exerts its functions remain incompletely understood. Here, we report that activation of β-catenin leads to the up-regulation of inhibitory molecule T-cell immunoglobulin and mucin domain 3 (Tim-3) in type 1 conventional DCs (cDC1s). Using a cDC1-targeted vaccine model with anti-DEC-205 engineered to express the melanoma antigen human gp100 (anti-DEC-205-hgp100), we demonstrated that CD11c-β-cateninactive mice exhibited impaired cross-priming and memory responses of gp100-specific CD8 T (Pmel-1) cells upon immunization with anti-DEC-205-hgp100. Single-cell RNA sequencing (scRNA-seq) analysis revealed that β-catenin in DCs negatively regulated transcription programs for effector function and proliferation of primed Pmel-1 cells, correlating with suppressed CD8 T cell immunity in CD11c-β-cateninactive mice. Further experiments showed that treating CD11c-β-cateninactive mice with an anti-Tim-3 antibody upon anti-DEC-205-hgp100 vaccination led to restored cross-priming and memory responses of gp100-specific CD8 T cells, suggesting that anti-Tim-3 treatment likely synergizes with DC vaccines to improve their efficacy. Indeed, treating B16F10-bearing mice with DC vaccines using anti-DEC-205-hgp100 in combination with anti-Tim-3 treatment resulted in significantly reduced tumor growth compared with treatment with the DC vaccine alone. Taken together, we identified the β-catenin/Tim-3 axis as a potentially novel mechanism to inhibit anti-tumor CD8 T cell immunity and that combination immunotherapy of a DC-targeted vaccine with anti-Tim-3 treatment leads to improved anti-tumor efficacy.

Establishment of novel anti-TIM-3 antibodies interfering with its binding to ligands

The T cell immunoglobulin and mucin-domain containing-3 (TIM-3) receptor has gained significant attention as a promising target for cancer immunotherapy. The inhibitory effect of T cells by TIM-3 is mediated through the interaction between TIM-3 and its ligands. Ligand-blocking anti-TIM-3 antibodies possess the potential to reactivate antigen-specific T cells and augment anti-tumor immunity. However, the precise ligand-receptor interactions disrupted by the administration of TIM-3 blocking Abs have yet to be fully elucidated. In this study, we have developed a panel of monoclonal antibodies targeting human TIM-3, namely MsT001, MsT065, MsT229, and MsT286. They exhibited high sensitivities (10 pg/mL) and affinities (3.70 × 10-9 to 4.61 × 10-11 M) for TIM-3. The TIM-3 antibodies recognized distinct epitopes, including linear epitopes (MsT001 and MsT065), and a conformational epitope (MsT229 and MsT286). Additionally, the MsT229 and MsT286 displayed reactivity towards cynomolgus TIM-3. The interactions between TIM-3/Gal-9, TIM-3/HMGB-1, and TIM-3/CEACAM-1 disrupt the binding of MsT229 and MsT286, while leaving the binding of MsT001 and MsT065 unaffected. The inhibitory effect on the interaction between Gal-9 and TIM-3 was found to be dose-dependently in the presence of either MsT229 or MsT286. The findings suggested that the involvement of conformational epitopes in TIM-3 is crucial for its interaction with ligands, and we successfully generated novel anti-TIM-3 Abs that exhibit inhibitory potential. In conclusion, our finding offers valuable insights -on the comprehension and targeting of human TIM-3.

Immune Modulation with RANKL Blockade through Denosumab Treatment in Patients with Cancer

Denosumab is a fully human mAb that binds receptor activator of NFκB ligand (RANKL). It is routinely administered to patients with cancer to reduce the incidence of new bone metastasis. RANK-RANKL interactions regulate bone turnover by controlling osteoclast recruitment, development, and activity. However, these interactions also can regulate immune cells including dendritic cells and medullary thymic epithelial cells. Inhibition of the latter results in reduced thymic negative selection of T cells and could enhance the generation of tumor-specific T cells. We examined whether administering denosumab could modify modulate circulating immune cells in patients with cancer. Blood was collected from 23 patients with prostate cancer and 3 patients with renal cell carcinoma, all of whom had advanced disease and were receiving denosumab, prior to and during denosumab treatment. Using high-dimensional mass cytometry, we found that denosumab treatment by itself induced modest effects on circulating immune cell frequency and activation. We also found minimal changes in the circulating T-cell repertoire and the frequency of new thymic emigrants with denosumab treatment. However, when we stratified patients by whether they were receiving chemotherapy and/or steroids, patients receiving these concomitant treatments showed significantly greater immune modulation, including an increase in the frequency of natural killer cells early and classical monocytes later. We also saw broad induction of CTLA-4 and TIM3 expression in circulating lymphocytes and some monocyte populations. These findings suggest that denosumab treatment by itself has modest immunomodulatory effects, but when combined with conventional cancer treatments, can lead to the induction of immunologic checkpoints. See related Spotlight by Nasrollahi and Davar, p. 383.

Early-Responsive Immunoregulation Therapy Improved Microenvironment for Bone Regeneration Via Engineered Extracellular Vesicles

Overactivated inflammatory reactions hinder the bone regeneration process. Timely transformation of microenvironment from pro-inflammatory to anti-inflammatory after acute immune response is favorable for osteogenesis. Macrophages play an important role in the immune response to inflammation. Therefore, this study adopts TIM3 high expression extracellular vesicles (EVs) with immunosuppressive function to reshape the early immune microenvironment of bone injury, mainly by targeting macrophages. These EVs can be phagocytosed by macrophages, thereby increasing the infiltration of TIM3-positive macrophages (TIM3+ macrophages) and M2 subtypes. The TIM3+ macrophage group has some characteristics of M2 macrophages and secretes cytokines, such as IL-10 and TGF-β1 to regulate inflammation. TIM3, which is highly expressed in the engineered EVs, mediates the release of anti-inflammatory cytokines by inhibiting the p38/MAPK pathway and promotes osseointegration by activating the Bmp2 promoter to enhance macrophage BMP2 secretion. After evenly loading the engineered EVs into the hydrogel, the continuous and slow release of EVsTIM3OE recruits more anti-inflammatory macrophages during the early stages of bone defect repair, regulating the immune microenvironment and eliminating the adverse effects of excessive inflammation. In summary, this study provides a new strategy for the treatment of refractory wounds through early inflammation control.

Dendritic cells as orchestrators of anticancer immunity and immunotherapy

Dendritic cells (DCs) are a heterogeneous group of antigen-presenting innate immune cells that regulate adaptive immunity, including against cancer. Therefore, understanding the precise activities of DCs in tumours and patients with cancer is important. The classification of DC subsets has historically been based on ontogeny; however, single-cell analyses are now additionally revealing a diversity of functional states of DCs in cancer. DCs can promote the activation of potent antitumour T cells and immune responses via numerous mechanisms, although they can also be hijacked by tumour-mediated factors to contribute to immune tolerance and cancer progression. Consequently, DC activities are often key determinants of the efficacy of immunotherapies, including immune-checkpoint inhibitors. Potentiating the antitumour functions of DCs or using them as tools to orchestrate short-term and long-term anticancer immunity has immense but as-yet underexploited therapeutic potential. In this Review, we outline the nature and emerging complexity of DC states as well as their functions in regulating adaptive immunity across different cancer types. We also describe how DCs are required for the success of current immunotherapies and explore the inherent potential of targeting DCs for cancer therapy. We focus on novel insights on DCs derived from patients with different cancers, single-cell studies of DCs and their relevance to therapeutic strategies.

Promising immunotherapy targets: TIM3, LAG3, and TIGIT joined the party

Immune checkpoint inhibitors (ICIs) have shown great promise as immunotherapy for restoring T cell function and reactivating anti-tumor immunity. The US Food and Drug Administration (FDA) approved the first immune checkpoint inhibitor, ipilimumab, in 2011 for advanced melanoma patients, leading to significant improvements in survival rates. Subsequently, other immune checkpoint-targeting antibodies were tested. Currently, seven ICIs, namely ipilimumab (anti-cytotoxic T lymphocyte-associated protein 4 [CTLA4]), pembrolizumab, nivolumab (anti-programmed cell death protein 1 [PD-1]), atezolizumab, avelumab, durvalumab, and cemiplimab (anti-PD-L1), have been approved for various cancer types. However, the efficacy of antibodies targeting CTLA4 or PD-1/programmed death-ligand 1 (PD-L1) remains suboptimal. Consequently, ongoing studies are evaluating the next generation of ICIs, such as lymphocyte activation gene-3 (LAG3), T cell immunoglobulin and mucin-domain containing 3 (TIM3), and T cell immunoglobulin and ITIM domain (TIGIT). Our review provides a summary of clinical trials evaluating these novel immune checkpoints in cancer treatment.

The role of TIM-3 in sepsis: a promising target for immunotherapy?

Sepsis remains a significant cause of mortality and morbidity worldwide, with limited effective treatment options. The T-cell immunoglobulin and mucin domain-containing molecule 3 (TIM-3) has emerged as a potential therapeutic target in various immune-related disorders. This narrative review aims to explore the role of TIM-3 in sepsis and evaluate its potential as a promising target for immunotherapy. We discuss the dynamic expression patterns of TIM-3 during sepsis and its involvement in regulating immune responses. Furthermore, we examine the preclinical studies investigating the regulation of TIM-3 signaling pathways in septic models, highlighting the potential therapeutic benefits and challenges associated with targeting TIM-3. Overall, this review emphasizes the importance of TIM-3 in sepsis pathogenesis and underscores the promising prospects of TIM-3-based immunotherapy as a potential strategy to combat this life-threatening condition.

Beyond T cell exhaustion: TIM-3 regulation of myeloid cells

T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3) is an important immune checkpoint molecule initially identified as a marker of IFN-γ-producing CD4+ and CD8+ T cells. Since then, our understanding of its role in immune responses has significantly expanded. Here, we review emerging evidence demonstrating unexpected roles for TIM-3 as a key regulator of myeloid cell function, in addition to recent work establishing TIM-3 as a delineator of terminal T cell exhaustion, thereby positioning TIM-3 at the interface between fatigued immune responses and reinvigoration. We share our perspective on the antagonism between TIM-3 and T cell stemness, discussing both cell-intrinsic and cell-extrinsic mechanisms underlying this relationship. Looking forward, we discuss approaches to decipher the underlying mechanisms by which TIM-3 regulates stemness, which has remarkable potential for the treatment of cancer, autoimmunity, and autoinflammation.

Inhibitory receptors of plasmacytoid dendritic cells as possible targets for checkpoint blockade in cancer

Plasmacytoid dendritic cells (pDCs) are the major producers of type I interferons (IFNs), which are essential to mount antiviral and antitumoral immune responses. To avoid exaggerated levels of type I IFNs, which pave the way to immune dysregulation and autoimmunity, pDC activation is strictly regulated by a variety of inhibitory receptors (IRs). In tumors, pDCs display an exhausted phenotype and correlate with an unfavorable prognosis, which largely depends on the accumulation of immunosuppressive cytokines and oncometabolites. This review explores the hypothesis that tumor microenvironment may reduce the release of type I IFNs also by a more pDC-specific mechanism, namely the engagement of IRs. Literature shows that many cancer types express de novo, or overexpress, IR ligands (such as BST2, PCNA, CAECAM-1 and modified surface carbohydrates) which often represent a strong predictor of poor outcome and metastasis. In line with this, tumor cells expressing ligands engaging IRs such as BDCA-2, ILT7, TIM3 and CD44 block pDC activation, while this blocking is prevented when IR engagement or signaling is inhibited. Based on this evidence, we propose that the regulation of IFN secretion by IRs may be regarded as an "innate checkpoint", reminiscent of the function of "classical" adaptive immune checkpoints, like PD1 expressed in CD8+ T cells, which restrain autoimmunity and immunopathology but favor chronic infections and tumors. However, we also point out that further work is needed to fully unravel the biology of tumor-associated pDCs, the neat contribution of pDC exhaustion in tumor growth following the engagement of IRs, especially those expressed also by other leukocytes, and their therapeutic potential as targets of combined immune checkpoint blockade in cancer immunotherapy.

A programmable releasing versatile hydrogel platform boosts systemic immune responses via sculpting tumor immunogenicity and reversing tolerogenic dendritic cells

Immunogenicity improvement is a valuable strategy for tumor immunotherapy. However, immunosuppressive factors bestow tolerogenic phenotype on tumor-infiltrating DCs, which exhibit weak antigen presentation and strong anti-inflammatory cytokines secretion abilities, limiting the effectiveness of tumor immunotherapy even if the tumor has adequate immunogenicity. Herein, we designed a programmable releasing versatile hydrogel platform (PIVOT) to sculpt tumor immunogenicity, increase intratumoral DCs and cDC1s abundance, and reverse the tolerogenic phenotype of DCs, thus promoting their maturation for boosting innate and adaptive immune responses. Responsive to tumoral reactive oxygen species (ROS), the hydrogel splits and promotes the activation of DCs and macrophages. Then, oxaliplatin is first released from PIVOT to sculpt tumor immunogenicity by inducing immunogenic cell death (ICD) and causing tumoral DNA fragments exposure simultaneously. Subsequently, the impaired DNA fragments bind to high mobility group protein 1 (HMGB1) forming the DNA-HMGB1 complex. Moreover, exogenous FMS-like tyrosine kinase 3 ligand (Flt-3L) recruits masses of DCs, especially cDC1s, which will endocytose the complex benefiting from TIM-3 blockade (αTIM3) that can reverse tolerogenic DCs. Finally, the endocytosis activates the cGAS-STING pathway of cDC1s, which promotes the secretion of type I IFN that triggers innate immune responses, and CXCL9 which recruits CD8+ effector T cells to initiate the following adaptive immune response against tumor progress. PIVOT achieves nearly 90 % tumor growth inhibition and induces systemic antitumor immune responses. In conclusion, this study focuses on ICD-mediated tumor immunogenicity sculpture and nucleic acid endocytosis-involved tolerogenic DCs reversal, providing a novel paradigm for enhancing DCs-based antitumor immune responses.

Targeting the NF-κB pathway as a potential regulator of immune checkpoints in cancer immunotherapy

Advances in cancer immunotherapy over the last decade have led to the development of several agents that affect immune checkpoints. Inhibitory receptors expressed on T cells that negatively regulate the immune response include cytotoxic T‑lymphocyte antigen 4 (CTLA4) and programmed cell death protein 1 (PD1), which have been studied more than similar receptors. Inhibition of these proteins and other immune checkpoints can stimulate the immune system to attack cancer cells, and prevent the tumor from escaping the immune response. However, the administration of anti-PD1 and anti-CTLA4 antibodies has been associated with adverse inflammatory responses similar to autoimmune diseases. The current review discussed the role of the NF-κB pathway as a tumor promoter, and how it can govern inflammatory responses and affect various immune checkpoints. More precise knowledge about the communication between immune checkpoints and NF-κB pathways could increase the effectiveness of immunotherapy and reduce the adverse effects of checkpoint inhibitor therapy.