TIM3 comes of age as an inhibitory receptor

Microdroplet-enhanced chip platform for high-throughput immunotherapy marker screening from extracellular vesicle RNAs and membrane proteins

Extracellular vesicles (EVs) are considered as promising candidates for predicting patients who respond to immunotherapy. Nevertheless, simultaneous detection of multiple EVs markers still presents significant technical challenges. In this work, we developed a high-throughput microdroplet-enhanced chip (MEC) platform, which utilizes thousands of individual microchambers (∼pL) as reactors, accelerating the detection efficiency of the CRISPR/Cas systems and increasing the sensitivity by up to 100-fold (aM level). Ten biomarkers (including 5 RNAs and 5 proteins) from patients' EVs are successfully detected on one chip, and the comprehensive markers show increased accuracy (AUC 0.911) than the individual marker for the efficacy prediction of immunotherapy. This platform provides a high-throughput yet sensitive strategy for screening immunotherapy markers in clinical.

Spatial analyses revealed CXCL5 and SLC6A14 as the markers of microvascular invasion in intrahepatic cholangiocarcinoma

BACKGROUND

Microvascular invasion (MVI) is a critical prognostic factor in intrahepatic cholangiocarcinoma (ICC), strongly associated with postoperative recurrence. However, the phenotypic features and spatial organization of MVI remain inadequately understood.

METHODS

We performed a spatial transcriptomic analysis on 29,632 spots from six ICC samples, manually delineating MVI clusters using the cloupe software. Key biomarkers were identified and validated in an independent cohort of 135 ICC patients. Functional and survival analyses were conducted to assess clinical relevance, and cell-cell communication pathways were investigated.

RESULTS

MVI regions exhibited heightened proliferation, angiogenesis, and epithelial-mesenchymal transition, driven by increased expression of transcription factors SOX10, ZEB1, and SNAI2. CXCL5 and SLC6A14 were identified as potential MVI biomarkers and showed high expression in tumor-invasive areas. Serum CXCL5 demonstrated strong predictive power for vascular invasion (AUC = 0.92) and intrahepatic metastasis (AUC = 0.96). High expression of both CXCL5 and SLC6A14 was associated with the worst survival outcomes. MVI regions were enriched with immunosuppressive MRC1+ macrophages and exhibited elevated immune checkpoint expression, including HAVCR2 and TIGHT, indicative of immune resistance. Cell-cell communication analysis revealed CXCL5-CXCR2 and LGALS9-HAVCR2 as key ligand-receptor pairs contributing to the immunosuppressive microenvironment.

CONCLUSIONS

This study identifies CXCL5 and SLC6A14 as key biomarkers of MVI, highlighting their roles in tumor proliferation, immune resistance, and poor clinical outcomes. These findings provide valuable insights into the spatial organization of MVI and its contribution to ICC progression, offering potential therapeutic targets.

Features and prognostic significance of soluble TIM-3 and its ligands Gal-9 and CEACAM1 levels in the diagnostic bone marrow of adult acute myeloid leukemia patients

The prognostic significance of soluble immune checkpoint molecule TIM-3 and its ligands in the plasma has been illustrated in various solid tumors, but such study in newly diagnosed acute myeloid leukemia (AML) remains absent. Soluble TIM-3, Gal-9, and CEACAM1 levels in bone marrow plasma samples collected from 90 adult AML patients at diagnosis and 12 healthy donors were measured by enzyme-linked immunosorbent assays, and 16 AML patients were simultaneously tested cell membrane TIM-3 expression by multicolor flow cytometry. AML patients had significantly elevated soluble TIM-3 levels and similar soluble Gal-9 and CEACAM1 levels compared with healthy donors (P = 0.0003, 0.26, and 0.96, respectively). In the whole cohort, a high soluble TIM-3 level was the sole independent adverse prognostic factor for relapse-free survival (RFS) (P = 0.0060), and together with adverse European LeukemiaNet genetic risk they were independent poor prognostic factors for event-free survival (P = 0.0030 and 0.0040, respectively). A high soluble CEACAM1 level was significantly related to lower RFS (P = 0.028). In addition, a high soluble Gal-9 level had a significant association with lower RFS in patients receiving allogeneic hematopoietic stem cell transplantation at the first complete remission (P = 0.037). Furthermore, soluble TIM-3 level tended to have positive correlation with the percentage of nonblast myeloid TIM-3+ cells in nucleated cells in AML (r = 0.48, P = 0.073). Therefore, the high soluble TIM-3 level in the diagnostic BM plasma predicted poor outcome in adult AML patients, and a high sGal-9 level was associated with relapse after allogeneic hematopoietic stem cell transplantation.

Machine learning-optimized targeted detection of alternative splicing

RNA sequencing (RNA-seq) is widely adopted for transcriptome analysis but has inherent biases that hinder the comprehensive detection and quantification of alternative splicing. To address this, we present an efficient targeted RNA-seq method that greatly enriches for splicing-informative junction-spanning reads. Local splicing variation sequencing (LSV-seq) utilizes multiplexed reverse transcription from highly scalable pools of primers anchored near splicing events of interest. Primers are designed using Optimal Prime, a novel machine learning algorithm trained on the performance of thousands of primer sequences. In experimental benchmarks, LSV-seq achieves high on-target capture rates and concordance with RNA-seq, while requiring significantly lower sequencing depth. Leveraging deep learning splicing code predictions, we used LSV-seq to target events with low coverage in GTEx RNA-seq data and newly discover hundreds of tissue-specific splicing events. Our results demonstrate the ability of LSV-seq to quantify splicing of events of interest at high-throughput and with exceptional sensitivity.

A comprehensive review of immune checkpoint inhibitors for cancer treatment

Immunology-based therapies are emerging as an effective cancer treatment, using the body's immune system to target tumors. Immune checkpoints, which regulate immune responses to prevent tissue damage and autoimmunity, are often exploited by cancer cells to avoid destruction. The discovery of checkpoint proteins like PD-1/PD-L1 and CTLA-4 was pivotal in developing cancer immunotherapy. Immune checkpoint inhibitors (ICIs) have shown great success, with FDA-approved drugs like PD-1 inhibitors (Nivolumab, Pembrolizumab, Cemiplimab), PD-L1 inhibitors (Atezolizumab, Durvalumab, Avelumab), and CTLA-4 inhibitors (Ipilimumab, Tremelimumab), alongside LAG-3 inhibitor Relatlimab. Research continues on new checkpoints like TIM-3, VISTA, B7-H3, BTLA, and TIGIT. Biomarkers like PDL-1 expression, tumor mutation burden, interferon-γ presence, microbiome composition, and extracellular matrix characteristics play a crucial role in predicting responses to immunotherapy with checkpoint inhibitors. Despite their effectiveness, not all patients experience the same level of benefit, and organ-specific immune-related adverse events (irAEs) such as rash or itching, colitis, diarrhea, hyperthyroidism, and hypothyroidism may occur. Given the rapid advancements in this field and the variability in patient outcomes, there is an urgent need for a comprehensive review that consolidates the latest findings on immune checkpoint inhibitors, covering their clinical status, biomarkers, resistance mechanisms, strategies to overcome resistance, and associated adverse effects. This review aims to fill this gap by providing an analysis of the current clinical status of ICIs, emerging biomarkers, mechanisms of resistance, strategies to enhance therapeutic efficacy, and assessment of adverse effects. This review is crucial to furthering our understanding of ICIs and optimizing their application in cancer therapy.

Immunotherapeutic strategies beyond the PD-1/PD-L1 pathway in head and neck squamous cell carcinoma - A scoping review on current developments in agents targeting TIM-3, TIGIT, LAG-3, and VISTA

Head and neck squamous cell carcinoma (HNSCC) poses a considerable challenge due to its high incidence and mortality rates. Immunotherapy targeting PD-(L)1 emerges as a promising approach for HNSCC, as it has the potential to trigger a broad and long-lasting anti-tumor response. Nevertheless, the effectiveness of immunotherapy encounters hurdles, and only a small proportion of patients benefit, with many eventually experiencing relapse. Consequently, there is a pursuit of strategies to enhance overall treatment outcomes. Understanding the mechanisms driving resistance to PD-(L)1 inhibition and devising strategies to overcome these challenges are vital for advancing more effective treatments. Furthermore, gaining insights into the mechanisms of action and safety profiles of novel combination therapies is critical for their successful adoption in clinical practice. As a result, current research is dedicated to investigating various immunotherapeutic agents beyond the PD-1/PD-L1 axis. This review offers a comprehensive overview of the existing immunotherapy strategies in HNSCC with a focus on TIM-3, TIGIT, LAG-3, and VISTA. The aim is to lay a strong foundation for the continual advancement of therapies for HNSCC.

The emerging role of TIM-3 in colorectal cancer: a promising target for immunotherapy

INTRODUCTION

Colorectal cancer (CRC) imposes a substantial worldwide health burden, necessitating innovative strategies to enhance therapeutic outcomes. T cell immunoglobulin-3 (Tim-3), an immune checkpoint, enhances immunological tolerance. Tim-3's role in CRC surpasses its conventional function as an indicator of dysfunction in T lymphocytes.

AREAS COVERED

This review provides an all-inclusive summary of the structural and functional attributes of Tim-3's involvement in the case of CRC. It explores the implications of Tim-3 expression in CRC with regard to tumor progression, clinical characteristics, and therapeutic approaches. Furthermore, it delves into the intricate signaling pathways and molecular mechanisms through which Tim-3 exerts its dual function in both immunity against tumors and immune evasion.

EXPERT OPINION

Understanding Tim-3's complicated network of interactions in CRC has significant consequences for the development of novel immunotherapeutic strategies targeted toward restoring anti-tumor immune responses and improving patient survival. Tim-3 is an important and valuable target for CRC patient risk classification and treatment because it regulates a complex network of strategies for suppressing immune responses, including causing T cell exhaustion, increasing Treg (regulatory T-cell) proliferation, and altering antigen-presenting cell activity.

Revolutionizing cancer treatment: the rise of personalized immunotherapies

Interest in biological therapy for cancer has surged due to its precise targeting of cancer cells and minimized impact on surrounding healthy tissues. This review discusses various biological cancer therapies, highlighting advanced alternatives over conventional chemotherapy alone. It explores DNA and RNA-based vaccines, T-cell modifications, adoptive cell transfer, CAR T cell therapy, angiogenesis inhibitors, and the combination of immunotherapy with chemotherapy, offering a holistic view of the potential in cancer treatment. Additionally, it discusses the role of nanotechnology in increasing the efficacy of cancer-targeting drugs, as well as cytokine and immunoconjugate therapies for bolstering immune system effectiveness against neoplastic cells. The potential of gene potential for precise targeting of cancer-linked genes and the application of oncolytic viruses against virus-associated cancers are also discussed. The review identifies significant advancements in the targeted treatment of cancer by biological methods. It acknowledges the challenges, including drug resistance and the need for high specificity in certain therapies, while also highlighting the effectiveness of cancer vaccines, modified T-cells, and oncolytic viruses. Biological therapies are a promising frontier in cancer treatment, offering the potential for more personalized and effective therapeutic strategies. Despite existing challenges, ongoing research and clinical trials are fundamental for overcoming current limitations and enhancing the efficacy of biological therapies in cancer care.

Tim-3 pathway dysregulation and targeting in sepsis-induced immunosuppression

Sepsis is a major medical problem which causes millions of deaths worldwide every year. The host immune response in sepsis is characterized by acute inflammation and a simultaneous state of immunosuppression. In the later stage of sepsis, immunosuppression is a crucial factor that increases the susceptibility of septic patients to secondary infection and mortality. It is characterized by T cell exhaustion, excessive production of anti-inflammatory cytokines, hyperproliferation of immune suppressor cells and aberrant expression of immune checkpoint molecules. T cell immunoglobulin and mucin domain 3 (Tim-3), an immune checkpoint molecule, is found on the surface of various cells, including macrophages, NK cells, NKT cells, and T cells. There are four different ligands for Tim-3, and accumulating evidence indicates that Tim-3 and its ligands play a crucial role in regulating immune cell dysfunction during sepsis. Anti-Tim-3 antibodies have been applied in the field of cancer immunotherapy and have achieved positive therapeutic effects in some clinical trials. However, the therapeutic efficacy of Tim-3 blockade is still controversial in animal models of sepsis. These challenges highlight the need for a deeper understanding of Tim-3 signaling in sepsis. This review examines the comprehensive effect of Tim-3 signaling in the development of sepsis-induced immunosuppression and the therapeutic efficacy of Tim-3 blockade.

Neoadjuvant immunotherapy and oncolytic virotherapy in HPV positive and HPV negative skin cancer: A comprehensive review

Skin cancer is the most common new cancer among Caucasians. This cancer has different types, of which non-melanoma skin cancer is the most common type. Various factors affect this disease, one of which is viral infections, including HPV. This virus plays an important role in skin cancer, especially cSCCs. There are various options for the treatment of skin cancer, and today special attention has been paid to treatments based on therapeutic goals, immunotherapy and combination therapy. In this study, we have investigated treatments based on immunotherapy and virotherapy and the effect of HPV virus on the effectiveness of these treatments in skin cancer. Treatments based on virotherapy are performed for a long time in combination with other common treatments such as radiotherapy and chemotherapy in order to have a greater effect and lower its side effects, which include: shortness of breath, tachycardia, lowering blood pressure in the patient. Also, the most important axis of immunotherapy is to focus on PD1-PDL1, despite abundant evidence on the importance of immunotherapy, many studies investigate the use of immunotherapy inhibitors in the adjuvant and neoadjuvant setting in various cancers. Also, previous findings show conflicting evidence of the effect of HPV status on the response to immunotherapy.

Immune checkpoints in B-cell Lymphoma: Still an Unmet challenge from Basic research to clinical practice

In the last decade, advancements in immunotherapy knowledge have highlighted CTLA-4, PD-1, LAG-3, TIM-3, and TIGIT, decisive immune checkpoints exhibiting within the tumor microenvironment (TME), as fundamental objects for cancer immunotherapy. The widespread clinical use of immune checkpoint inhibitors (ICls), employing PD-1/PD-L1 or CTLA-4 antibodies to obstruct crucial checkpoint regulators, is noted in treating B-cell lymphoma patients. Nevertheless, the prolonged advantages of the currently employed treatments against CTLA-4, PD-1, and PD-L1 are uncommon among patients. Thus, recent focus has been progressively moved to additional immune checkpoints on T cells, like LAG-3, TIM-3, and TIGIT, which are now seen as reassuring targets for treatment and broadly acknowledged. There are several types of immunecheckpoint molecules expressed by T cells, and inhibitors targeting immune checkpoints can revive and amplify the immune response of T lymphocytes against tumors, a crucial aspect in lymphoma therapy. However, there is little knowledge about their regulation. Herein, we discuss the anti-tumor effects and functions of ICIs in controlling T-cell activity, as well as the progress in combined application with other immunotherapies.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Fyn, an important molecule in the brain, is a potential therapeutic target for brain tumours

Under normal physiological conditions, Fyn, a nonreceptor tyrosine kinase, is involved in signal transduction pathways in the nervous system and in the formation and activation of T lymphocytes. Fyn is a member of the Src family of kinases (SFKs) and plays a role in cell morphogenic transformation, motility, proliferation, and death, which in turn influences the development and progression of various cancer types. SFKs are overexpressed or hyperactive in tumours, and they are engaged in several signalling pathways that lead to tumour development. Inhibition of Fyn can enhance patient outcomes and prolong survival. Thus, Fyn is a desirable therapeutic target in a variety of tumour types. To lay the groundwork for further investigation and targeted therapy in tumours, in this article, we review the most recent findings on the function of Fyn in tumours, with an emphasis on its role in gliomas. Understanding the function of Fyn during tumourigenesis and development and in resistance to anticancer therapeutic agents can aid in the development and application of innovative medicines that specifically target this kinase, thus improving the management of cancers.

Concurrent intratumoural Treg cell depletion and CD8+ T cell expansion via a cleavable anti-4-1BB-interleukin-15 fusion protein

Potent agonists of the inducible co-stimulatory receptor 4-1BB are too toxic for patients with advanced cancer. Here, on the basis of observations of a weak agonist of 4-1BB depleting regulatory T (Treg) cells within the tumour microenvironment without leading to substantial restoration of dysfunctional cytotoxic T cells (CTLs), we show that effective tumour control can be achieved via concurrent Treg cell depletion and CTL expansion through an anti-4-1BB antibody fused to interleukin-15 (IL-15) via a peptide sensitive to tumour proteases. In mouse models of advanced cancers, intraperitoneal injection of the bifunctional protein attenuated the activity of the interleukin mostly in the periphery of the primary tumour while allowing for the expansion of CTLs within the tumour microenvironment, led to more effective tumour inhibition and to lower systemic toxicity than treating the cancers with combinatorial treatment with unlinked anti-4-1BB antibody and IL-15, and reduced the resistance of tumours to checkpoint blockade. Concurrent eradication of Treg cells and activation of tumour-infiltrating lymphocytes may represent a general strategy for the effective control of advanced metastatic tumours.

Siglec-G Suppresses CD8+ T Cells Responses through Metabolic Rewiring and Can be Targeted to Enhance Tumor Immunotherapy

CD8+ T cells play a critical role in cancer immune-surveillance and pathogen elimination. However, their effector function can be severely impaired by inhibitory receptors such as programmed death-1 (PD-1) and T cell immunoglobulin domain and mucin domain-3 (Tim-3). Here Siglec-G is identified as a coinhibitory receptor that limits CD8+ T cell function. Siglec-G is highly expressed on tumor-infiltrating T cells and is enriched in the exhausted T cell subset. Ablation of Siglec-G enhances the efficacy of adoptively transferred T cells and chimeric antigen receptor (CAR) T cells in suppressing solid tumors growth. Mechanistically, sialoglycan ligands, such as CD24 on tumor cells, activate the Siglec-G-SHP2 axis in CD8+ T cells, impairing metabolic reprogramming from oxidative phosphorylation to glycolysis, which dampens cytotoxic T lymphocyte (CTL) activation, expansion, and cytotoxicity. These findings discover a critical role for Siglec-G in inhibiting CD8+ T cell responses, suggesting its potential therapeutic effect in adoptive T cell therapy and tumor immunotherapy.

Unravelling the Reasons Behind Limited Response to Anti-PD Therapy in ATC: A Comprehensive Evaluation of Tumor-Infiltrating Immune Cells and Checkpoints

Inhibiting the immune checkpoint (ICP) PD-1 based on PD-L1 expression status has revolutionized the treatment of various cancers, yet its efficacy in anaplastic thyroid carcinoma (ATC) remains limited. The therapeutic response depends upon multiple factors, particularly the conduciveness of the tumor's immune milieu. This study comprehensively evaluated and classified ATC's immune microenvironment (IME) to elucidate the factors behind suboptimal response to anti-PD therapy. Utilizing multiplex-immunofluorescence and immunohistochemistry, we retrospectively analyzed 26 cases of ATC for expression of ICPs PD-L1, PD-1, CTLA4, TIM3, and Galectin-9 and tumor-infiltrating cytotoxic T lymphocytes (CTL)-the effector cells, the anti-tumor NK cells, the immune-inhibitory myeloid-derived suppressor (MDSC) and regulatory T (Treg) cells, and B lymphocytes. Most ATCs (65%) exhibited PD-L1 positivity, but only 31%, in addition, had abundant CTL (type I IME), a combination associated with a better response to ICP inhibition. Additionally, PD-1 expression levels on CTL were low/absent in most cases-a "target-missing" situation-unfavorable for an adequate therapeutic response. All but one ATC showed nuclear Galectin-9 expression. The documentation of nuclear expression of Galectin-9 akin to benign thyroid is a first, and its role in ATC pathobiology needs further elucidation. In addition to less abundant PD-1 expression on CTL, the presence of MDSC, Treg, and exhausted cytotoxic T lymphocytes in the immune milieu of ATC can contribute to anti-PD resistance. TIM3, the most frequently expressed ICP on CTL, followed by CTLA4, provides alternate therapeutic targets in ATC. The co-expression of multiple immune checkpoints is of great interest for ATC since these data also open the avenue for combination therapies.

Inflammation in myelodysplastic syndrome pathogenesis

Inflammation is a key driver of the progression of preleukemic myeloid conditions, such as clonal hematopoiesis of indeterminate potential (CHIP) and clonal cytopenia of undetermined significance (CCUS), to myelodysplastic syndromes (MDS). Inflammation is a critical mediator in the complex interplay of the genetic, epigenetic, and microenvironmental factors contributing to clonal evolution. Under inflammatory conditions, somatic mutations in TET2, DNMT3A, and ASXL1, the most frequently mutated genes in CHIP and CCUS, induce a competitive advantage to hematopoietic stem and progenitor cells, which leads to their clonal expansion in the bone marrow. Chronic inflammation also drives metabolic reprogramming and immune system deregulation, further promoting the expansion of malignant clones. This review underscores the urgent need to fully elucidate the role of inflammation in MDS initiation and highlights the potential of the therapeutical targeting of inflammatory pathways as an early intervention in MDS.

Phosphatidylserine externalization as immune checkpoint in cancer

Cancer is the second leading cause of mortality worldwide. Despite recent advances in cancer treatment including immunotherapy with immune checkpoint inhibitors, new unconventional biomarkers and targets for the detection, prognosis, and treatment of cancer are still in high demand. Tumor cells are characterized by mutations that allow their unlimited growth, program their local microenvironment to support tumor growth, and spread towards distant sites. While a major focus has been on altered tumor genomes and proteomes, crucial signaling molecules such as lipids have been underappreciated. One of these molecules is the membrane phospholipid phosphatidylserine (PS) that is usually found at cytosolic surfaces of cellular membranes but can be rapidly and massively shuttled to the extracellular leaflet of the plasma membrane during apoptosis to serve as a limiting factor for immune responses. These immunosuppressive interactions are exploited by tumor cells to evade the immune system. In this review, we describe mechanisms of immune regulation in tumors, discuss if PS may constitute an inhibitory immune checkpoint, and describe current and future strategies for targeting PS to reactivate the tumor-associated immune system.

Tumor Microenvironment Drives the Cross-Talk Between Co-Stimulatory and Inhibitory Molecules in Tumor-Infiltrating Lymphocytes: Implications for Optimizing Immunotherapy Outcomes

This review explores some of the complex mechanisms underlying antitumor T-cell response, with a specific focus on the balance and cross-talk between selected co-stimulatory and inhibitory pathways. The tumor microenvironment (TME) fosters both T-cell activation and exhaustion, a dual role influenced by the local presence of inhibitory immune checkpoints (ICs), which are exploited by cancer cells to evade immune surveillance. Recent advancements in IC blockade (ICB) therapies have transformed cancer treatment. However, only a fraction of patients respond favorably, highlighting the need for predictive biomarkers and combination therapies to overcome ICB resistance. A crucial aspect is represented by the complexity of the TME, which encompasses diverse cell types that either enhance or suppress immune responses. This review underscores the importance of identifying the most critical cross-talk between inhibitory and co-stimulatory molecules for developing approaches tailored to patient-specific molecular and immune profiles to maximize the therapeutic efficacy of IC inhibitors and enhance clinical outcomes.

Tim-3 Deficiency Ameliorates Motor Deficits and Neuroinflammation in MPP+/MPTP-Induced Parkinson's Disease Models via the NF-κB/NLRP3 Pathway

Parkinson's disease (PD) is a common neurodegenerative disorder, and neuroinflammation plays a pivotal role in its pathogenesis. T-cell immunoglobulin and mucin-domain-containing molecule 3 (Tim-3) is a crucial immunoregulatory mediator in various diseases; however, its roles and underlying molecular mechanisms in PD remain unclear. We established in vitro and in vivo 1-methyl-4-phenylpyridinium (MPP+)/1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD models in Tim-3-knockout BV2 cells and mice, respectively. Motor function was assessed through behavioral tests, including pole, traction, forced swimming, and open field tests. Immunofluorescence was used to examine dopaminergic neuron loss and glial activation. The expression levels of nuclear factor-kappa B (NF-κB)/nucleotide-binding oligomerization domain-like receptor 3 (NLRP3) pathway components were evaluated by western blotting. Proinflammatory cytokines were measured via enzyme-linked immunosorbent assay (ELISA). Compared with the wild-type, Tim-3 expression was significantly increased in the PD model, and Tim-3 deficiency mitigated MPTP-induced motor deficits, dopaminergic neuron loss, and glial cell activation. Furthermore, Tim-3 deficiency suppressed neuroinflammation by negatively modulating the NF-κB/NLRP3 pathway, thereby downregulating the expression of the proinflammatory cytokines IL-1β, IL-18, IL-6, and TNF-α. These findings indicate that Tim-3 plays a proinflammatory role in PD by regulating the NF-κB/NLRP3 pathway, highlighting Tim-3 as a promising therapeutic target for PD.

New Developments and Therapeutic Drug Monitoring Options in Costimulatory Blockade in Solid Organ Transplantation: A Systematic Critical Review

PURPOSE

In this review, the authors summarized the latest developments in costimulatory blockade to prevent rejection after solid organ transplantation (SOT) and discussed possibilities for future research and the need for therapeutic drug monitoring (TDM) of these agents.

METHODS

Studies about costimulatory blockers in SOT in humans or animal transplant models in the past decade (2014-2024) were systematically reviewed in PubMed, European Union clinical trials (EudraCT), and ClinicalTrials.gov.

RESULTS

Seventy-five registered clinical trials and 58 published articles were found on costimulation blockade of the CD28-CD80/86, CD40-CD40L, and OX40-OX40L pathways. Belatacept, an antagonist of the CD28-CD80/86 pathway, is the only approved costimulatory agent in SOT, hence accounting for most of the research. Other identified costimulatory blocking agents included abatacept and CD28 antagonists tegoprubart, dazodalibep, and TNX-1500. Although tegoprubart was unsuccessful in pancreas transplantation in nonhuman primates, trials in human kidney transplantation are underway. Dazodalibep trials faced recruitment challenges. TNX-1500 was unsuccessful in animal studies and is currently not pursued in humans. After discontinuation of iscalimab (CD40-CD154 pathway antagonist) in SOT, the alternatives, bleselumab and KPL404, showed promising results in kidney transplantation and cardiac xenotransplantation. Studies on secondary costimulatory pathway antagonists, such as OX40-OX40L, have only used animal models. Despite the low interindividual variability in pharmacokinetics (PK) in all studied agents, TDM could be useful for optimizing dosing in PK/pharmacodynamic (PD) studies.

CONCLUSIONS

The routine use of costimulation blockade in SOT is hindered by problems in efficacy compared with the standard of care. Costimulatory inhibitors could be combined in a calcineurin inhibitor-free regimen. Future PK/pharmacodynamic studies in costimulatory agents and personalized medicine could warrant TDM of these agents.

Impaired mitochondrial oxidative phosphorylation induces CD8+ T cell exhaustion

CD8+ T cells play a crucial role in anti-tumor immunity, but their function can be impaired by exhaustion induced by prolonged antigen stimulation. Mitochondrial dysfunction, a hallmark of the tumor microenvironment (TME), has been linked to various pathologies, but its specific role in CD8+ T cell exhaustion remains underexplored. Here, we established an in vitro model of CD8+ T cell exhaustion by co-culturing OVA-specific OT1 CD8+ T cells with OVA-expressing MC38 tumor cells. Next, we investigated the impact of mitochondrial dysfunction on exhaustion using pharmacological inhibitors targeting the electron transport chain. The role of the mitochondrial complex I component NDUFA10 was further examined through genetic knockout in CD8+ T cells using CRISPR-Cas9. Inhibition of the mitochondrial electron transport chain significantly accelerated CD8+ T cell exhaustion in vitro. Knockout of NDUFA10 in CD8+ T cells led to enhanced tumor growth and increased exhaustion of tumor-infiltrating CD8+ T cells in a Rag1-/- tumor-bearing transfer model. This study highlights the critical role of mitochondrial function in regulating CD8+ T cell exhaustion and anti-tumor activity, providing new insights into the metabolic underpinnings of immune dysfunction in cancer.

Parkin paves the path to antitumor immunity: Expanding Parkin's role as a tumor suppressor

Parkin, a ring-between-ring-type E3 ubiquitin ligase, first shown to play a critical role in autosomal recessive juvenile Parkinsonism, has recently emerged as a key player in cancer biology. Parkin is now known to serve as a tumor suppressor, and its deregulation frequently promotes tumorigenesis. In this issue of the JCI, Perego et al. expand that role by showing that Parkin expression stimulated an interferon (IFN) response to modulate CD8+ T cell activity. These findings suggest that, in addition to directly inhibiting tumor progression, Parkin enhances antitumor immune responses, highlighting it as a promising therapeutic target for cancer treatment.

Palmitoylation of TIM-3 promotes immune exhaustion and restrains antitumor immunity

T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3) is an immune checkpoint that has critical roles in immune exhaustion. However, little is known about the mechanisms that regulate TIM-3 surface expression and turnover. Here, we report that human TIM-3 is palmitoylated by the palmitoyltransferase DHHC9 at residue cysteine 296 (Cys296). Palmitoylation stabilized TIM-3 by preventing binding to E3 ubiquitin ligase HRD1, thereby suppressing its polyubiquitination and degradation. DHHC9 knockdown attenuated chimeric antigen receptor T (CAR-T) cell exhaustion, and a peptidic inhibitor of TIM-3 palmitoylation accelerated TIM-3 degradation and enhanced antitumor immunity mediated by CAR-T cells and natural killer (NK) cells. In hepatocellular carcinoma, DHHC9 expression correlated with TIM-3 expression in CD8+ T cells and NK cells, and high DHHC9 expression was associated with shorter survival in patients with high TIM-3. These findings demonstrate that palmitoylation of TIM-3 catalyzed by DHHC9 promotes its stability, resulting in immune exhaustion and impaired antitumor immunity.

Integrated bioinformatic analysis and experimental validation for exploring the key immune checkpoint of COPD

BACKGROUND

There is growing evidence indicating immune inflammation is a key factor in the progression of chronic obstructive pulmonary disease (COPD). Immune checkpoints (ICs) are crucial targets for modulating the functional activation and differentiation of immune cells, particularly in relation to immune inflammation and the regulation of T cell activation and exhaustion. However, the precise mechanisms of ICs in COPD remain understood.

METHODS

COPD datasets were obtained from the Gene Expression Omnibus (GEO) and analyzed using GEO2R and Limma to identify differentially expressed genes. LASSO regression was then applied to screen ICs closely associated with COPD. Finally, target genes were selected based on gene expression profiles. Gene ontology (GO), immune infiltration analysis, and gene set enrichment analysis (GSEA) were utilized to assess the relationship between IC genes (ICGs) and immune cells. Subsequently, tobacco-exposed mice, anti-Tim3-treated mice, and HAVCR2-knockout mice were generated, with flow cytometry being used to confirm the results.

RESULTS

Through the analysis of GSE38974 and LASSO regression, five ICGs were identified. Subsequent validation using GSE20257 and GSE76925 confirmed these findings. Gene expression profiling highlighted HAVCR2 as having the strongest correlation with COPD. Further investigation through immune infiltration analysis, GO, and GSEA indicated a link between HAVCR2 and CD8+ T cells in COPD. Flow cytometry experiments demonstrated high Tim3 expression in CD8+ T cells of mice exposed to tobacco, promoting Tc1 and inhibiting Tc17, thus affecting CD8+ Tem activation and CD8+ Tcm formation, leading to an immune imbalance within CD8+ T cells.

CONCLUSION

Prolonged exposure to tobacco upregulates Tim3 in CD8+ T cells, triggering its regulatory effects on Tc1/Tc17. Knocking out HAVCR2 further upregulated the expression of CD8+ Tem while suppressing the expression of CD8+ Tcm, indicating that Tim3 plays a role in the activation and differentiation of CD8+ T cells in the context of tobacco exposure.

NFIL3/Tim3 axis regulates effector Th1 inflammation in COPD mice

Background

IFN-γ+CD4+ cells (type 1 helper T cells, Th1) represent a critical component of the inflammatory environment in the lungs of chronic obstructive pulmonary disease (COPD). Identifying influencing factors related to COPD-associated Th1 cells will enhance our understanding of the inflammatory mechanisms involved and facilitate the development of targeted interventions.

Method

We describe T-cell immunoglobulin and mucin-domain containing-3 (Tim3) as a key gene regulating COPD-associated Th1 cells through single-cell sequencing, flow cytometry and knockout mice.

Results

Our findings indicate that Havcr2 expression gradually increases during CD4+ T cell activation in COPD mice, with Tim3 being highly expressed on both CD4+ T cells and Th1 cells. Notably, the knockout of HAVCR2 further promotes the infiltration of CD4+ T cells and the expression of IFN-γ in the lungs, resulting in a more severe emphysema phenotype, although it does not significantly affect TNF-α expression. Additionally, NFIL3, an upstream regulator of Tim3, is also highly expressed in the CD4+ T cells of COPD mice. Mice with NFIL3 knockout exhibit phenotypes similar to those of HAVCR2 knockout mice, along with a significant downregulation of Tim3 expression. In vitro, we simulated the activation process by polarizing primary CD4+ Tn cells from COPD mice and observed that NFIL3/Tim3 expression was significantly upregulated following Th1 polarization.

Conclusion

Our study demonstrates that the NFIL3/Tim3 axis plays a role in Th1 imbalance in the lungs of COPD by inhibiting Th1 differentiation.

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.

Spatial Context of Immune Checkpoints as Predictors of Overall Survival in Patients with Resectable Colorectal Cancer Independent of Standard Tumor-Node-Metastasis Stages

SIGNIFICANCE

The identification of specific spatial patterns of immune checkpoint expression that correlate with overall survival in patients with colon cancer suggests a potential prognostic tool for risk stratification and treatment selection. These findings pave the way for the development of novel therapeutic strategies to enhance antitumor immune responses.

Molecular Hydrogen Therapy in Aneurysmal SAH With RA and Newly-diagnosed SLE, Complicated With Acute Ischemic Infarction: A Case Report of Improved Immune Markers Including Tr1 Cells, Breg Cells and TIM3 Expression on Tc Cells

BACKGROUND/AIM

Most nontraumatic subarachnoid hemorrhages (SAHs) are caused by ruptured saccular aneurysms, often resulting in a devastating clinical event characterized by high mortality and significant morbidity among survivors. Numerous studies have confirmed the neuroprotective effects of the molecular hydrogen due to its unique biological properties.

CASE REPORT

We present the case of a 44-year-old female with aneurysmal SAH with rheumatoid arthritis (RA) and newly diagnosed systemic lupus erythematosus (SLE), complicated by acute ischemic infarction. Despite surgical, pharmacological and non-pharmacological interventions, including embolization of the aneurysm, immunosuppressant, non-vitamin K antagonist oral anticoagulant (NOAC), and plasmapheresis, loss of consciousness continued. The patient began daily treatment with hydrogen capsules, resulting in increased in Treg cells, Breg cells, increased TIM3+ expression on Tc cells, and the conversion of anti-dsDNA from positive to negative. Her clinical symptoms stabilized without adverse effects.

CONCLUSION

This case highlights the potential benefits of molecular hydrogen therapy in managing aneurysmal SAH with underlying autoimmune disease, warranting further research.

Influencing immunity: role of extracellular vesicles in tumor immune checkpoint dynamics

Immune checkpoint proteins (ICPs) serve as critical regulators of the immune system, ensuring protection against damage due to overly activated immune responses. However, within the tumor environment, excessive ICP activation weakens antitumor immunity. Despite the development of numerous immune checkpoint blockade (ICB) drugs in recent years, their broad application has been inhibited by uncertainties about their clinical efficacy. A thorough understanding of ICP regulation in the tumor microenvironment is essential for advancing the development of more effective and safer ICB therapies. Extracellular vesicles (EVs), which are pivotal mediators of cell-cell communication, have been extensively studied and found to play key roles in the functionality of ICPs. Nonetheless, a comprehensive review summarizing the current knowledge about the crosstalk between EVs and ICPs in the tumor environment is lacking. In this review, we summarize the interactions between EVs and several widely studied ICPs as well as their potential clinical implications, providing a theoretical basis for further investigation of EV-related ICB therapeutic approaches.

Epigenetic agents plus anti-PD-1 reprogram the tumor microenvironment and restore antitumor efficacy in Hodgkin lymphoma

ABSTRACT

DNA methyltransferase inhibitor decitabine plus anti-programmed cell death 1 (DP) therapy was effective in relapsed/refractory classic Hodgkin lymphoma (cHL). However, a subset of patients experienced primary resistance or relapse/progression after DP therapy. In this study, we evaluated the efficacy and safety of a triplet regimen consisting of the histone deacetylase inhibitor chidamide, decitabine, and anti-PD-1 camrelizumab (CDP) in 52 patients who previously received DP therapy. CDP treatment was well tolerated and resulted in an objective response rate of 94% (95% confidence interval [CI], 84-99), with 50% (95% CI, 36-64) of patients achieving complete response (CR). Notably, all patients who were recalcitrant to previous DP treatment exhibited therapeutic responses after CDP therapy, although their CR rate was lower than patients responsive to prior DP. Overall, the median progression-free survival was 29.4 months. Through single-cell RNA sequencing of pretreatment and on-treatment cHL tumor biopsy samples, we observed the heterogeneity of rare malignant Hodgkin Reed/Sternberg (HRS)-like cells. The classical CD30+ HRS-like cells interacted with abundant immunosuppressive IL21+CD4+ T helper cells, forming a positive feedback loop that supported their survival. While the CD30- HRS-like cell population showed potential resistance to anti-PD-1 immunotherapy. CDP treatment promoted the activation of diverse tumor-reactive CD8+ T cells and suppressed the proliferation of IL21+CD4+ T cells by inhibiting STAT1/3 signaling, thereby alleviating their immunosuppressive effects. These findings provide insights into the cHL microenvironment that contributes to anti-PD-1 resistance and highlight the therapeutic effectiveness of dual epi-immunotherapy in overcoming immunotherapy resistance. This trial was registered at www.clinicaltrials.gov as #NCT04233294.

Membrane Antigen Targeting in Acute Myeloid Leukemia Using Antibodies or CAR-T Cells

This review explores the emerging area of the therapeutic use of antibodies and chimeric antigen receptor (CAR)-T cells for the treatment of acute myeloid leukemia (AML). Through a detailed analysis of the existing literature, this paper highlights the different categories of AML antigens for immunotherapeutic targeting, the most recent applications on antibodies, including bispecific immune cell engagers and CAR-T cells, to the therapy of patients with refractory/relapsing AML The studies performed in AML patients using BisAbs and CAR-T cells have shown that only a limited number of AML patients show sustained responses to these therapies, thus underlying AML heterogeneity as a major challenge. Several studies have addressed the potential mechanisms underlying the resistance of AMLs to antibody-directed immunotherapies. A better understanding of the barriers hampering the successful development of AML immunotherapy is required. However, in spite of the limitations, the studies recently carried out have shown the peculiar sensitivity of some AML subtypes to immunotherapy and have provided the basis for future studies, such as multiplex antigen targeting, which hold the promise of successful development.

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.

Hippo pathway in cancer cells induces NCAM1+αSMA+ fibroblasts to modulate tumor microenvironment

Cancer cells adeptly manipulate the tumor microenvironment (TME) to evade host antitumor immunity. However, the role of cancer cell-intrinsic signaling in shaping the immunosuppressive TME remains unclear. Here, we found that the Hippo pathway in cancer cells orchestrates the TME by influencing the composition of cancer-associated fibroblasts (CAFs). In a 4T1 mouse breast cancer model, Hippo pathway kinases, large tumor suppressor 1 and 2 (LATS1/2), promoted the formation of neural cell adhesion molecule 1 (NCAM1)+alpha-smooth muscle actin (αSMA)+ CAFs expressing the transforming growth factor-β, which is associated with T cell inactivation and dysfunction. Depletion of LATS1/2 in cancer cells resulted in a less immunosuppressive TME, indicated by the reduced proportions of NCAM1+αSMA+ CAFs and dysfunctional T cells. Notably, similar Hippo pathway-induced NCAM1+αSMA+ CAFs were observed in human breast cancer, highlighting the potential of TME-manipulating strategies to reduce immunosuppression in cancer immunotherapy.

Discovery of new myositis genetic associations through leveraging other immune-mediated diseases

Genome-wide association studies (GWASs) have been successful at finding associations between genetic variants and human traits, including the immune-mediated diseases (IMDs). However, the requirement of large sample sizes for discovery poses a challenge for learning about less common diseases, where increasing volunteer numbers might not be feasible. An example of this is myositis (or idiopathic inflammatory myopathies [IIM]s), a group of rare, heterogeneous autoimmune diseases affecting skeletal muscle and other organs, severely impairing life quality. Here, we applied a feature engineering method to borrow information from larger IMD GWASs to find new genetic associations with IIM and its subgroups. Combining this approach with two clustering methods, we found 17 IMDs genetically close to IIM, including some common comorbid conditions, such as systemic sclerosis and Sjögren's syndrome, as well as hypo- and hyperthyroidism. All IIM subtypes were genetically similar within this framework. Next, we colocalized IIM signals that overlapped IMD signals, and found seven potentially novel myositis associations mapped to immune-related genes, including BLK, IRF5/TNPO3, and ITK/HAVCR2, implicating a role for both B and T cells in IIM. This work proposes a new paradigm of genetic discovery in rarer diseases by leveraging information from more common IMD, and can be expanded to other conditions and traits beyond IMD.

A novel bioinformatics pipeline for the identification of immune inhibitory receptors as potential therapeutic targets

Despite major successes with inhibitory receptor blockade in cancer, the identification of novel inhibitory receptors as putative drug targets is needed due to lack of durable responses, therapy resistance, and side effects. Most inhibitory receptors signal via immunoreceptor tyrosine-based inhibitory motifs (ITIMs) and previous studies estimated that our genome contains over 1600 ITIM-bearing transmembrane proteins. However, testing and development of these candidates requires increased understanding of their expression patterns and likelihood to function as inhibitory receptor. Therefore, we designed a novel bioinformatics pipeline integrating machine learning-guided structural predictions and sequence-based likelihood models to identify putative inhibitory receptors. Using transcriptomics data of immune cells, we determined the expression of these novel inhibitory receptors, and classified them into previously proposed functional categories. Known and putative inhibitory receptors were expressed across different immune cell subsets with cell type-specific expression patterns. Furthermore, putative immune inhibitory receptors were differentially expressed in subsets of tumour infiltrating T cells. In conclusion, we present an inhibitory receptor pipeline that identifies 51 known and 390 novel human inhibitory receptors. This pipeline will support future drug target selection across diseases where therapeutic targeting of immune inhibitory receptors is warranted.

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.

Dietary protein modulates intestinal dendritic cells to establish mucosal homeostasis

Dietary proteins are taken up by intestinal dendritic cells (DCs), cleaved into peptides, loaded to major histocompatibility complexes, and presented to T cells to generate an immune response. Amino acid (AA)-diets do not have the same effects because AAs cannot bind to major histocompatibility complex to activate T cells. Here, we show that impairment in regulatory T cell generation and loss of tolerance in mice fed a diet lacking whole protein is associated with major transcriptional changes in intestinal DCs including downregulation of genes related to DC maturation, activation and decreased gene expression of immune checkpoint molecules. Moreover, the AA-diet had a profound effect on microbiome composition, including an increase in Akkermansia muciniphilia and Oscillibacter and a decrease in Lactococcus lactis and Bifidobacterium. Although microbiome transfer experiments showed that AA-driven microbiome modulates intestinal DC gene expression, most of the unique transcriptional change in DC was linked to the absence of whole protein in the diet. Our findings highlight the importance of dietary proteins for intestinal DC function and mucosal tolerance.

Exploration of protein and genetic targets causing atrioventricular block: mendelian-randomization analyses based on eQTL data and pQTL data

BACKGROUND

Atrioventricular block (AVB) is a heterogeneous group of arrhythmias. AVB can lead to sudden arrest of the heart and subsequent syncope or sudden cardiac death. Few scholars have investigated the underlying molecular mechanisms of AVB. Finding molecular markers can facilitate understanding of AVB and exploration of therapeutic targets.

METHODS

Two-sample Mendelian randomization (MR) analysis was undertaken with inverse variance weighted (IVW) model and Wald ratio as the primary approach. Reverse MR analysis was undertaken to identify the associated protein targets and gene targets. Expression quantitative trait loci (eQTL) data from the eQTLGen database and protein quantitative trait loci (pQTL) data from three previous large-scale proteomic studies on plasma were retrieved as exposure data. Genome-wide association study (GWAS) summary data (586 cases and 379,215 controls) for AVB were retrieved from the UK Biobank database. Colocalization analyses were undertaken to identify the effect of filtered markers on outcome data. Databases (DrugBank, Therapeutic Target, PubChem) were used to identify drugs that interacted with targets.

RESULTS

We discovered that 692 genes and 42 proteins showed a significant correlation with the AVB phenotype. Proteins (cadherin-5, sTie-1, Notch 1) and genes (DNAJC30, ABO) were putative molecules to AVB. Drug-interaction analyses revealed anticancer drugs such as tyrosine-kinase inhibitors and TIMD3 inhibitors could cause AVB. Other substances (e.g. toxins, neurological drugs) could also cause AVB.

CONCLUSIONS

We identified the proteins (cadherin-5, sTie-1, Notch 1) and gene (DNAJC30, ABO) targets associated with AVB pathogenesis. Anticancer drugs (tyrosine-kinase inhibitors, TIMD3 inhibitors), toxins, or neurological drugs could also cause AVB.

The miRNA and PD-1/PD-L1 signaling axis: an arsenal of immunotherapeutic targets against lung cancer

Lung cancer is a severe challenge to the health care system with intrinsic resistance to first and second-line chemo/radiotherapies. In view of the sterile environment of lung cancer, several immunotherapeutic drugs including nivolumab, pembrolizumab, atezolizumab, and durvalumab are currently being used in clinics globally with the intention of releasing exhausted T-cells back against refractory tumor cells. Immunotherapies have a limited response rate and may cause immune-related adverse events (irAEs) in some patients. Hence, a deeper understanding of regulating immune checkpoint interactions could significantly enhance lung cancer treatments. In this review, we explore the role of miRNAs in modulating immunogenic responses against tumors. We discuss various aspects of how manipulating these checkpoints can bias the immune system's response against lung cancer. Specifically, we examine how altering the miRNA profile can impact the activity of various immune checkpoint inhibitors, focusing on the PD-1/PD-L1 pathway within the complex landscape of lung cancer. We believe that a clear understanding of the host's miRNA profile can influence the efficacy of checkpoint inhibitors and significantly contribute to existing immunotherapies for lung cancer patients. Additionally, we discuss ongoing clinical trials involving immunotherapeutic drugs, both as standalone treatments and in combination with other therapies, intending to advance the development of immunotherapy for lung cancer.

Machine learning-optimized targeted detection of alternative splicing

RNA-sequencing (RNA-seq) is widely adopted for transcriptome analysis but has inherent biases which hinder the comprehensive detection and quantification of alternative splicing. To address this, we present an efficient targeted RNA-seq method that greatly enriches for splicing-informative junction-spanning reads. Local Splicing Variation sequencing (LSV-seq) utilizes multiplexed reverse transcription from highly scalable pools of primers anchored near splicing events of interest. Primers are designed using Optimal Prime, a novel machine learning algorithm trained on the performance of thousands of primer sequences. In experimental benchmarks, LSV-seq achieves high on-target capture rates and concordance with RNA-seq, while requiring significantly lower sequencing depth. Leveraging deep learning splicing code predictions, we used LSV-seq to target events with low coverage in GTEx RNA-seq data and newly discover hundreds of tissue-specific splicing events. Our results demonstrate the ability of LSV-seq to quantify splicing of events of interest at high-throughput and with exceptional sensitivity.

Rethinking Immune Check Point Inhibitors Use in Liver Transplantation: Implications and Resistance

Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy, including the two most common liver tumors, hepatocellular carcinoma and cholangiocarcinoma, but their use in the peri-transplantation period is controversial. ICI therapy aims to heighten cytotoxic T lymphocytes response against tumors. However, tumor recurrence is common owing to tumor immune response escape involving ablation of CTL response by interfering with antigen presentation, triggering CLT apoptosis and inducing epigenetic changes that promote ICI therapy resistance. ICI can also affect tissue resident memory T cell population, impact tolerance in the post-transplant period, and induce acute inflammation risking graft survival post-transplant. Their interaction with immunosuppression may be key in reducing tumor burden and may thus, require multimodal therapy to treat these tumors. This review summarizes ICI use in the liver transplantation period, their impact on tolerance and resistance, and new potential therapies for combination or sequential treatments for liver tumors.

Innate immune cells in tumor microenvironment: A new frontier in cancer immunotherapy

Innate immune cells, crucial in resisting infections and initiating adaptive immunity, play diverse and significant roles in tumor development. These cells, including macrophages, granulocytes, dendritic cells (DCs), innate lymphoid cells, and innate-like T cells, are pivotal in the tumor microenvironment (TME). Innate immune cells are crucial components of the TME, based on which various immunotherapy strategies have been explored. Immunotherapy strategies, such as novel immune checkpoint inhibitors, STING/CD40 agonists, macrophage-based surface backpack anchoring, ex vivo polarization approaches, DC-based tumor vaccines, and CAR-engineered innate immune cells, aim to enhance their anti-tumor potential and counteract cancer-induced immunosuppression. The proximity of innate immune cells to tumor cells in the TME also makes them excellent drug carriers. In this review, we will first provide a systematic overview of innate immune cells within the TME and then discuss innate cell-based therapeutic strategies. Furthermore, the research obstacles and perspectives within the field will also be addressed.

Recurrent ocular toxoplasmosis is associated with interferon-gamma deficiency possibly due to genetic origin

OBJECTIVE

Ocular toxoplasmosis (OT) can cause posterior uveitis; causes of recurrent OT are not well understood. We explored clinical, immunological and genetic properties associated with recurrent OT.

METHODS AND ANALYSIS

A recurrent OT patient population (n=9) was identified. Clinical history, ophthalmological findings and immunological properties were assessed. B and T cell immunophenotyping including interferon-gamma (IFN-γ) responses were analysed. An analysis of 592 immunodeficiency genes was performed.

RESULTS

The patients experienced 2-7 OT episodes (average 3.7). The first episode occurred at an average of 23.8 (SD 10.1) years of age. All patients had anterior uveitis, vitritis and various fundus lesions of OT. The patients had lymphocyte maturation abnormalities; the proportion of naive CD4+CD45RA+CCR7+ T cells was high in 5/9 cases, and the percentage of CD4+CD45RA-CCR7- T effector memory cells was reduced in 7/9 cases. An increased percentage of CD19+CD38lowCD21low activated B cells was observed in 5/9 cases. IFN-γ response was reduced in CD4+ (8.45±4.17 vs 21.27±11.0, p=0.025) and CD8+ (39.0±9.9 vs 18.1±18.1, p=0.017) T cells. Genetic analysis revealed several potentially harmful variants in immunologically active ERCC3, MANBA, IRF4, HAVCR2, CARMIL2, CD247, MPO, C2 and CD40 genes.

CONCLUSION

Our recurrent OT cases had deviations in lymphocyte maturation and IFN-γ responses possibly caused by genetic reasons. However, limitations of our study include failure to identify uniform genetic mechanisms. In addition, we cannot rule out the possibility that the immunological abnormalities can be triggered by chronic toxoplasmosis. Despite the limitations, our findings contribute to the understanding of ocular immunity and development of recurrent OT.

Reversal of T-cell exhaustion: Mechanisms and synergistic approaches

T cells suffer from long-term antigen stimulation and insufficient energy supply, leading to a decline in their effector functions, memory capabilities, and proliferative capacity, ultimately resulting in T cell exhaustion and an inability to perform normal immune functions in the tumor microenvironment. Therefore, exploring how to restore these exhausted T cells to a state with effector functions is of great significance. Exhausted T cells exhibit a spectrum of molecular alterations, such as heightened expression of inhibitory receptors, shifts in transcription factor profiles, and modifications across epigenetic, metabolic, and transcriptional landscapes. This review provides a comprehensive overview of various strategies to reverse T cell exhaustion, including immune checkpoint blockade, and explores the potential synergistic effects of combining multiple approaches to reverse T cell exhaustion. It offers new insights and methods for achieving more durable and effective reversal of T cell exhaustion.

Promising Therapeutic Strategies for Hematologic Malignancies: Innovations and Potential

In this review we explore innovative approaches in the treatment of hematologic cancers by combining various therapeutic modalities. We discuss the synergistic potential of combining inhibitors targeting different cellular pathways with immunotherapies, molecular therapies, and hormonal therapies. Examples include combining PI3K inhibitors with proteasome inhibitors, NF-κB inhibitors with immunotherapy checkpoint inhibitors, and neddylation inhibitors with therapies targeting the tumor microenvironment. Additionally, we discuss the potential use of small molecules and peptide inhibitors in hematologic cancer treatment. These multidimensional therapeutic combinations present promising strategies for enhancing treatment efficacy and overcoming resistance mechanisms. However, further clinical research is required to validate their effectiveness and safety profiles in hematologic cancer patients.

Alternative Strategies for Delivering Immunotherapeutics Targeting the PD-1/PD-L1 Immune Checkpoint in Cancer

The programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) immune checkpoint constitutes an inhibitory pathway best known for its regulation of cluster of differentiation 8 (CD8)+ T cell-mediated immune responses. Engagement of PD-L1 with PD-1 expressed on CD8+ T cells activates downstream signaling pathways that culminate in T cell exhaustion and/or apoptosis. Physiologically, these immunosuppressive effects exist to prevent autoimmunity, but cancer cells exploit this pathway by overexpressing PD-L1 to facilitate immune escape. Intravenously (IV) administered immune checkpoint inhibitors (ICIs) that block the interaction between PD-1/PD-L1 have achieved great success in reversing T cell exhaustion and promoting tumor regression in various malignancies. However, these ICIs can cause immune-related adverse events (irAEs) due to off-tumor toxicities which limits their therapeutic potential. Therefore, considerable effort has been channeled into exploring alternative delivery strategies that enhance tumor-directed delivery of PD-1/PD-L1 ICIs and reduce irAEs. Here, we briefly describe PD-1/PD-L1-targeted cancer immunotherapy and associated irAEs. We then provide a detailed review of alternative delivery approaches, including locoregional (LDD)-, oncolytic virus (OV)-, nanoparticle (NP)-, and ultrasound and microbubble (USMB)-mediated delivery that are currently under investigation for enhancing tumor-specific delivery to minimize toxic off-tumor effects. We conclude with a commentary on key challenges associated with these delivery methods and potential strategies to mitigate them.

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.

Quaternary ammoniums activate human dendritic cells and induce a specific T-cell response in vitro

BACKGROUND

In many countries, neuro-muscular blocking agents (NMBAs) are the first cause of perioperative anaphylaxis. Epidemiological studies identified pholcodine, a quaternary ammonium-containing opiate as one of the sensitization sources. However, NMBA anaphylaxis exists in countries where pholcodine was unavailable, prompting the hypothesis of other sensitizing molecules, most likely quaternary ammonium compounds (QACs). Indeed, QACs are commonly used as disinfectants, antiseptics, preservatives, and detergents. Occupational exposure to QACs has been reported as a risk factor for NMBA anaphylaxis, but little is known about the sensitization mechanism and the capacity of these molecules to elicit an immune response. We aimed to establish the immunogenicity of QACs representative of the main existing chemical structures.

METHODS

We measured the sensitization potential of seven QACs (two polyquaterniums, three alkyl-ammoniums and two aromatic ammoniums) by using two standard dendritic cells (DCs) models (THP-1 cell line and monocyte derived-dendritic cells). The allergenicity of the sensitizing compounds was further tested in heterologous and autologous T-cell-DC co-culture models.

RESULTS

Amongst the seven molecules tested, four could modulate activation markers on DCs, and thus can be classified as chemical sensitizers (polyquaterniums-7 and -10, ethylhexadecyldimethylammonium and benzethonium). This activation was accompanied by the secretion of pro-inflammatory and maturation cytokines. Furthermore, activation by polyquaternium-7 could induce T-cell proliferation in heterologous and autologous coculture models, demonstrating that this molecule can induce a specific CD4+ T cell response.

CONCLUSIONS

We provide evidence at the cellular level that some QACs can elicit an immune response, which could be in line with the hypothesis of these molecules' role in NMBA sensitization.