TIGIT in cancer immunotherapy

Immunophenotypical characterization of immune checkpoint receptor expression in cynomolgus monkeys and human healthy volunteers in resting and in T-cell stimulatory conditions in vitro

Immunotherapeutics targeting immune checkpoint receptors or their ligands (i.e., immune checkpoint inhibitors), have been groundbreaking in the field of oncology, radically changing the approach to treatment and improving the clinical outcomes of an ever-expanding list of solid tumors and hematological malignancies. However, immune checkpoint inhibitors (ICI) are not devoid of side effects, collectively regarded as immune-related adverse events (irAE); they are not easily uncovered in preclinical immunotoxicological investigations and are often due to the very low expression of their targets in immunologically-unchallenged non-clinical species. We have characterized expression of a broad range of immune checkpoint receptors in peripheral blood mononuclear cell (PBMC) subpopulations from cynomolgus monkeys and healthy human volunteers, under resting and T-cell stimulatory conditions by multicolor flow cytometry to inform appropriate species selection for modeling potential irAE in immunotherapeutic preclinical research. Focusing on the response of the main lymphocyte populations to interleukin (IL)-2 alone, or in combination with anti-CD3 and anti-CD28 antibodies, checkpoints with shared similarities and key differences between the two species were identified. The results of this first study provide a database for the expression and response to stimulation for immune checkpoint receptors and can help guide future model selection in the design of preclinical studies involving immunotherapeutics directed against these targets.

Emerging Immunotherapy Targets in Early Drug Development

Immunotherapy has significantly changed the treatment paradigm for solid tumors, with immune checkpoint inhibitors now established in the management of many malignancies. Despite initial success, durable responses remain limited to a subset of patients, often less than 30%, due to both intrinsic and acquired resistance mechanisms. These challenges have prompted the development of next-generation immunotherapies. Recent efforts have expanded the scope of immunotherapy beyond PD-1/PD-L1 and CTLA-4 inhibition, focusing on new immune targets currently under investigation in early phase clinical trials. These include novel immune checkpoint inhibitors, immunomodulators targeting the tumor microenvironment, and bispecific antibodies. This review provides a comprehensive overview of emerging immune targets currently being investigated in early drug development, discussing their mechanisms of action, preliminary clinical outcomes, and potential future directions.

Preclinical application of a CD155 targeting chimeric antigen receptor T cell therapy for digestive system cancers

Despite intensive multimodal therapy, the prognosis for patients with digestive system cancers remains poor. Cancer cell heterogeneity and immunosuppressive microenvironments are the main barriers to the effective CAR-T cell therapy with solid malignancies. In parallel, tumor-associated macrophages (TAMs) are essential for tumor immunosuppressive microenvironment formation. The limited efficacy of CAR-T cell therapy with solid malignancies prompted us to test whether new therapeutic target could enhance the antitumor activity of CAR-T cells with several digestive system cancer types. We determined CD155 expression in multiple human digestive system cancers, including gastric cancer, esophagus cancer, pancreatic cancer, and colon cancer, normal tissue samples and patient-derived M2-like tumor-associated macrophages. We developed a CD155-based CAR comprising the extracellular domain of human TIGIT, 4-1BB, and CD3z signaling domains (BBz). Furthermore, we validated the killing efficacy and safety of CD155-BBz CAR-T cells in vitro and in vivo using in-house established preclinical tumor models. CD155 was strongly and homogenously expressed in digestive system cancers but mildly in normal tissues, indicating it could be an ideal target for CAR-T cell therapy, moreover, TAMs that express CD155 possess an immunosuppressive M2-like profile. We found that CD155-BBz CAR-T cells can mediate significant antitumor activity in vivo, which induces complete tumor regression and long-lasting immunologic memory of established solid tumors in xenograft models. Our study indicates that CD155 is a promising target for digestive system cancer therapy, and CD155-targeting CAR-T cells perform a detecting power in digestive system cancer clinical trials.

Optimization of Immunotherapy Strategies Based on Spatiotemporal Heterogeneity of Tumour-Associated Tissue-Resident Memory T Cells

Tissue-resident memory T cells (TRMs) reside in peripheral tissues and provide rapid immune defence against local infection and tumours. Tumour-associated TRMs share common tissue-resident features and formation mechanisms, representing some unique subsets of tumour-infiltrating lymphocytes (TILs). However, differences in the tumour microenvironment(TME) and tumour evolution stage result in TRMs exhibiting temporal and spatial heterogeneity of phenotype and function not only at different stages, before and after treatment, but also between tumours originating from different tissues, primary and metastatic cancer, and tumour and adjacent normal tissue. The infiltration of TRMs is often associated with immunotherapy response and favourable prognosis; however, due to different definitions, it has been shown that some subtypes of TRMs can also have a negative impact. Therefore, it is crucial to precisely characterise the TRM subpopulations that can influence the therapeutic efficacy and clinical prognosis of various solid tumours. Here, we review the spatiotemporal heterogeneity of tumour-associated TRMs, as well as the differences in their impact on clinical outcomes. We also explore the relationship between TRMs and immune checkpoint blockade (ICB) and TIL therapy, providing insights into potential new targets and strategies for immunotherapy.

Advances in research on flavonoids in tumor immunotherapy (Review)

Cancer immunotherapy is an approach used in anti‑tumor treatment; however, its efficacy is limited to specific tumor types that are inherently sensitive to immune system modulation. Expanding the scope of indications and enhancing the efficacy of cancer immunotherapy are key goals for continued advancement. Flavonoids modulate the tumor‑immunosuppressive microenvironment. Integrating flavonoids with immunotherapeutic modalities, including cancer vaccines, immune checkpoint inhibitors and adoptive immune‑cell therapy, has potential in terms of augmenting the therapeutic efficacy of immunotherapy. The present review aimed to summarize flavonoids that enhance cancer immunotherapy, focusing on their underlying mechanisms and the application of nanotechnology to overcome inherent limitations such as poor solubility, low bioavailability, rapid metabolism, and instability under physiological conditions, thereby highlighting the potential of flavonoids in advancing cancer immunotherapy.

TIGIT antibody with PVR competitive ability enhances cancer immunotherapy and capable of eliciting anti-tumour immune memory

BACKGROUND

T-cell immunoreceptor with immunoglobulin (Ig) and ITIM domains (TIGIT) is a checkpoint receptor thought to be involved in mediating T-cell exhaustion and dysfunction of natural killer (NK) cells in tumours and is emerging as novel promising targets in immunotherapy, however, the ligand binding and the efficacy of its antibody still need to be further explored.

METHODS

Four different TIGIT antibodies in characteristics of antigen binding, in vitro effects on activated T cells, Fc region functions and tumour inhibition in animal models were compared. The antibody as monotherapy and combined with anti-PD-L1 antibody, effects on PBMC in ex vivo coculture with autologous human CRC organoids as well as PK profile were evaluated.

RESULTS

Studies demonstrated that TIGIT antibody with PVR-competitive ability as monotherapy resulted in inhibition of tumour growth, sustained anti-tumour immune memory in tumour re-challenge mice, enhanced anti-tumour therapy in combination with anti-PD-L1. Ex vivo coculture assay suggested that TIGIT antibody treatment activated immune cells and promoted infiltration and tumour killing ability of autologous PBMC in human CRC organoids.

CONCLUSIONS

Our study broadens the knowledge of TIGIT antibody in cancer immunotherapy and may benefit future development of next-generation checkpoint inhibitors with improved clinical outcomes.

Immune checkpoint inhibitor (ICI) therapy in central nervous system cancers: State-of-the-art and future outlook

Invasive central nervous system (CNS) cancers are an area where the development of breakthrough therapies is urgently needed. For instance, conditions such as glioblastoma multiforme (GBM) are associated with poor clinical prognosis, with the majority of trials offering no improvement to marginally enhanced survival. Unleashing the potential of targeting the immune system in CNS cancers has gained attention in recent years. Inhibition of immune checkpoints such as CTLA-4, PD-1/PD-L1, TIM-3, and LAG-3 has been attempted in recent trials. While potentially offering a notable edge over other immunotherapies, multi-organ adverse events have been found with the administration of immune checkpoint inhibitors (ICIs). The present review captures the state-of-the-art evidence on ICI treatments in different CNS cancers. Also, we discuss the value of combinational therapies involving ICIs as well as next-generation therapeutics such as bispecific antibodies targeting PD-1/LAG-3/TIM-3 and CRISPR-Cas9-edited PD-1-knock-out checkpoint-resistant CAR T-cells.

ST6GalNAc-I regulates tumor cell sialylation via NECTIN2/MUC5AC-mediated immunosuppression and angiogenesis in non-small cell lung cancer

Glycosylation controls immune evasion, tumor progression, and metastasis. However, how tumor cell sialylation regulates immune evasion remains poorly characterized. ST6GalNAc-I, a sialyltransferase that conjugates sialic acid to the glycans in glycoproteins, was overexpressed in an aggressive-type KPA (KrasG12D/+ Trp53R172H/+ Ad-Cre) lung adenocarcinoma (LUAD) model and patient samples. Proteomic and biochemical analysis indicated that ST6GalNAc-I mediated NECTIN2 sialylation in LUAD cells. ST6GalNAc-I-deficient tumor cells cocultured with T cells were more susceptible to T cell-mediated tumor cell killing, indicating a key role for NECTIN2 in T cell dysfunction. Mice injected with St6galnac-I-knockdown syngeneic cells showed reduced lung tumor incidence and Nectin2/Tigit-associated immunosuppression. ST6GalNAc-I-deficient cells exhibited reduced P-DMEA metabolite levels, while administration of P-DMEA promoted LUAD cell proliferation via MUC5AC. MUC5AC interacted and colocalized with PRRC1 in the Golgi, suggesting a potential role for PRRC1 in MUC5AC glycosylation. Mice injected with ST6GalNAc-I/MUC5AC-deficient cells (human LUAD) exhibited reduced lung tumor incidence, angiogenesis, and liver metastases. Mechanistically, ST6GalNAc-I/MUC5AC regulates VCAN-V1, a key factor in tumor matrix remodeling during angiogenesis and metastasis. These findings demonstrate that ST6GalNAc-I-mediated sialylation of NECTIN2/MUC5AC is critical for immune evasion and tumor angiogenesis. Targeting this pathway may prevent LUAD development and/or metastasis.

TP53 mutations and TET2 deficiency cooperate to drive leukemogenesis and establish an immunosuppressive environment

Mutations and deletions in TP53 are associated with adverse outcomes in patients with myeloid malignancies, and there is an urgent need for the development of improved therapies for TP53-mutant leukemias. Here, we identified mutations in TET2 as the most common co-occurring mutation in patients with TP53-mutant acute myeloid leukemia (AML). In mice, combined hematopoietic-specific deletion of TET2 and TP53 resulted in enhanced self-renewal compared with deletion of either gene alone. Tp53/Tet2 double-KO mice developed serially transplantable AML. Both mice and patients with AML with combined TET2/TP53 alterations upregulated innate immune signaling in malignant granulocyte-monocyte progenitors, which had leukemia-initiating capacity. A20 governs the leukemic maintenance by triggering aberrant noncanonical NF-κB signaling. Mice with Tp53/Tet2 loss had expansion of monocytic myeloid-derived suppressor cells (MDSCs), which impaired T cell proliferation and activation. Moreover, mice and patients with AML with combined TP53/TET2 alterations displayed increased expression of the TIGIT ligand, CD155, on malignant cells. TIGIT-blocking antibodies augmented NK cell-mediated killing of Tp53/Tet2 double-mutant AML cells, reduced leukemic burden, and prolonged survival in Tp53/Tet2 double-KO mice. These findings describe a leukemia-promoting link between TET2 and TP53 mutations and highlight therapeutic strategies to overcome the immunosuppressive bone marrow environment in this adverse subtype of AML.

Construction of a stromal cell-related prognostic signature based on a 101-combination machine learning framework for predicting prognosis and immunotherapy response in triple-negative breast cancer

Background

Triple-negative breast cancer (TNBC) is a highly aggressive subtype with limited therapeutic targets and poor immunotherapy outcomes. The tumor microenvironment (TME) plays a key role in cancer progression. Advances in single-cell transcriptomics have highlighted the impact of stromal cells on tumor progression, immune suppression, and immunotherapy. This study aims to identify stromal cell marker genes and develop a prognostic signature for predicting TNBC survival outcomes and immunotherapy response.

Methods

Single-cell RNA sequencing (scRNA-seq) datasets were retrieved from the Gene Expression Omnibus (GEO) database and annotated using known marker genes. Cell types preferentially distributed in TNBC were identified using odds ratios (OR). Bulk transcriptome data were analyzed using Weighted correlation network analysis (WGCNA) to identify myCAF-, VSMC-, and Pericyte-related genes (MVPRGs). A consensus MVP cell-related signature (MVPRS) was developed using 10 machine learning algorithms and 101 model combinations and validated in training and validation cohorts. Immune infiltration and immunotherapy response were assessed using CIBERSORT, ssGSEA, TIDE, IPS scores, and an independent cohort (GSE91061). FN1, a key gene in the model, was validated through qRT-PCR, immunohistochemistry, RNA interference, CCK-8 assay, apoptosis assay and wound-healing assay.

Results

In TNBC, three stromal cell subpopulations-myofibroblastic cancer-associated fibroblasts (myCAF), vascular smooth muscle cells (VSMCs), and pericytes-were enriched, exhibiting high interaction frequencies and strong associations with poor prognosis. A nine-gene prognostic model (MVPRS), developed from 23 prognostically significant genes among the 259 MVPRGs, demonstrated excellent predictive performance and was validated as an independent prognostic factor. A nomogram integrating MVPRS, age, stage, and tumor grade offered clinical utility. High-risk group showed reduced immune infiltration and increased activity in tumor-related pathways like ANGIOGENESIS and HYPOXIA, while low-risk groups responded better to immunotherapy based on TIDE and IPS scores. FN1, identified as a key oncogene, was highly expressed in TNBC tissues and cell lines, promoting proliferation and migration while inhibiting apoptosis.

Conclusion

This study reveals TNBC microenvironment heterogeneity and introduces a prognostic signature based on myCAF, VSMC, and Pericyte marker genes. MVPRS effectively predicts TNBC prognosis and immunotherapy response, providing guidance for personalized treatment. FN1 was validated as a key oncogene impacting TNBC progression and malignant phenotype, with potential as a therapeutic target.

TIGIT blockade increases efficacy of PD-1 blockade combined with radiation therapy in triple-negative breast cancer model

BACKGROUND AND PURPOSE

T-cell immunoreceptor with Ig and ITIM domains (TIGIT) suppresses functions of CD8+ T cells, and radiation therapy (RT) induces stimulation of regulatory T cells (Tregs), thereby limiting antitumor efficacy. This study aims to investigate the role of TIGIT in the immunosuppressive tumor environment and evaluate the potential of TIGIT blockade (αTIGIT) to enhance antitumor immune responses.

METHODS

We analyzed public transcriptomic data to identify the expression patterns of TIGIT on T cells in breast cancer and its prognostic impact. In addition, a murine TNBC model was utilized to evaluate the effects of αPD-1, local RT, and αTIGIT. T cells in tumors, tumor-draining lymph nodes (TdLNs), and the spleen were analyzed to assess the antitumor immune responses upon the treatments.

RESULTS

The analysis revealed that TIGIT is predominantly expressed on T cells within breast cancer, and the expression of TIGIT was associated with poor outcomes in TNBC patients. In the murine model, the combination of αPD-1 and RT increased TIGIT+CD226+CD8+ TILs, which are crucial for the efficacy of αTIGIT. Adding αTIGIT to αPD-1 and RT (αPD-1/RT) resulted in a synergistic antitumor effect, which was accompanied by increased infiltration of CD8+ TILs in both irradiated and nonirradiated tumors by the triple combination therapy compared to αPD-1/RT. The triple combination therapy also resulted in a less exhausted phenotype among CD8+ TILs and increased the proliferation of splenic CD8+ T cells. Moreover, αTIGIT significantly reduced Tregs in tumors, TdLNs, and the spleen when combined with αPD-1/RT.

CONCLUSION

αTIGIT exhibits synergistic effects when added to αPD-1/RT by increasing the infiltration and activation of CD8+ TILs while reducing Tregs. The study suggests that αTIGIT could be an effective strategy to enhance the antitumor efficacy of αPD-1 and RT in TNBC.

Comprehensive overview of antibody drug-related clinical studies in gynecology: insights from ClinicalTrials.gov

Antibodies have been widely used globally over the past decade and play an increasingly important role in modern medicine. Notably, significant advancements have been achieved in the realm of gynecology, particularly in gynecological cancers. This study endeavors to present a thorough overview of antibody-related drug clinical studies in gynecology registered on ClinicalTrials.gov, focusing on the basic characteristics of trials, geographical distribution, administration routes, indications, and targets. The analysis indicates a rising prevalence of antibody-drug conjugates (ADCs), bispecific antibodies, and Fc-fusion proteins. This study will help develop new ideas for future research on antibodies in gynecology.

Potential Roles of Serum Exosomal CD155 and its Impact on NK Cell Immunosuppression in Hepatocellular Carcinoma

Background

Targeted therapies directed at tumor immune checkpoint, like programmed death-ligand (PD-L)1/programmed death (PD)-1, have shown remarkable progress. Nevertheless, treatment efficacy in hepatocellular carcinoma (HCC) is notably compromised due to the intricate immune microenvironment. Exploring alternative checkpoints beyond PD-L1/PD-1, including those not located on the cell surface, may improve our understanding of their roles in areas like diagnostic potential and immune tolerance in HCC.

Aims

To explore the roles of serum exosomal CD155 (exo-CD155) in HCC.

Study Design

Experimental study.

Methods

We separated and analyzed serum exosomes from HCC patients. We quantified the concentrations of serum soluble CD155 (sCD155) and serum exo-CD155, and examined their association with disease progression, hepatitis B surface antigen (HBsAg) presence, and the concentrations of α-fetoprotein fraction L3 (AFP-L3) or alpha-fetoprotein (AFP). Additionally, we assessed the diagnostic effect through the receiver operating characteristic (ROC) curve, and the immune suppressive effect on natural killer (NK) cells of exo-CD155.

Results

This study reveal elevated exo-CD155 levels in all HCC patients, with a significant increase in early-stage patients, exhibiting normal AFP/AFP-L3 or HBsAg-positive status. Exo-CD155 is linked to the progression of HCC and shows significant diagnostic effectiveness for the disease. Furthermore, the incubation of NK-92MI with exosomes derived from HCC patients leads to a substantial reduction in immune function, which can be partially counteracted with an antibody that blocks T cell immune receptor immunoglobulin and ITIM domains, (TIGIT)-blocking antibody.

Conclusion

These results disclose exo-CD155 shows promise for serving as a biomarker for HCC, especially in early-stage patients or those with normal AFP/AFP-L3 levels. Moreover, serum exosomes from HCC patients suppress NK cell immune functions through the TIGIT/CD155 pathway, contributing to immune tolerance in HCC.

Immunotherapy in OSCC: Current trend and challenges

OBJECTIVES

Oral Cancer is one of the most prevalent malignant tumors of the head and neck. The three primary clinical treatments available till now for oral cancer are chemotherapy, radiation, and surgery. The goal of this review was to outline the basic principles of immunotherapy along with various immunotherapeutic agents on Oral Squamous Cell Carcinoma.

MATERIALS AND METHODS

A comprehensive search in PubMed, Scopus, and Google Scholar was performed using relevant keywords. All the articles, both English as well as non-English were included also with inclusion data from high-incidence countries (South-east Asia) and the compilation was ten done after getting the data reviewed from two pathologists who were blinded to the data.

RESULTS

All the data has been compiled and the various sections in the manuscript provides an insight into the current trends in immunotherapy.

CONCLUSIONS

Advanced research studies are needed to counteract the hurdles associated with immunotherapy so that a greater proportion of patients can be treated.

CLINICAL RELEVANCE

One of the more recent developments that is promising is immunotherapy, which can be quite beneficial when used as a monotherapy or an adjuvant treatment. This more recent treatment approach could serve as the fourth pillar in cancer care, alongside radiation, chemotherapy, and surgery. Because immunotherapy relies on the patient's immunological environment, careful patient selection is essential to its effectiveness.

Immuno-PET Imaging of a 68Ga-Labeled Single-Domain Antibody for Detecting Tumor TIGIT Expression

Preclinical studies have shown that the expression of T cell immunoglobulin and the immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) in the tumor microenvironment is associated with the efficacy of anti-TIGIT-based immunotherapy. This study aimed to develop a TIGIT single-domain antibody (sdAb)-based positron emission tomography (PET) radiotracer, [68Ga]Ga-NOTA-NABT3A1, and evaluate its characteristics. The NABT3A1 was modified with a NOTA derivative and radiolabeled with 68Ga. In vitro stability of [68Ga]Ga-NOTA-NABT3A1 was assessed in phosphate-buffered saline (PBS) and fetal bovine serum (FBS), along with its specificity for TIGIT stably transfected A375 Human melanoma cells (A375-TIGIT) was performed. In vivo imaging was conducted on A375-TIGIT tumor-bearing nude mice at different time points after the injection of [68Ga]Ga-NOTA-NABT3A1. The synthesized [68Ga]Ga-NOTA-NABT3A1 achieved a radiochemical yield of 70.56 ± 1.14% and purity levels of 95.80 ± 0.58% in PBS and 96.79 ± 1.69% in FBS at 2 h. Immuno-PET imaging revealed specific accumulation of [68Ga]Ga-NOTA-NABT3A1 in A375-TIGIT tumor-bearing nude mice, with a maximum uptake of 3.86 ± 0.29% injected dose/g at 0.5 h. Biodistribution and immunohistochemical analyses confirmed the in vivo imaging results. In conclusion, we successfully synthesized an NABT3A1-derived PET radiotracer with the potential to noninvasively assess TIGIT expression in tumors.

Revealing the mechanisms and therapeutic potential of immune checkpoint proteins across diverse protein families

Host immune responses to antigens are tightly regulated through the activation and inhibition of synergistic signaling networks that maintain homeostasis. Stimulatory checkpoint molecules initiate attacks on infected or tumor cells, while inhibitory molecules halt the immune response to prevent overreaction and self-injury. Multiple immune checkpoint proteins are grouped into families based on common structural domains or origins, yet the variability within and between these families remains largely unexplored. In this review, we discuss the current understanding of the mechanisms underlying the co-suppressive functions of CTLA-4, PD-1, and other prominent immune checkpoint pathways. Additionally, we examine the IgSF, PVR, TIM, SIRP, and TNF families, including key members such as TIGIT, LAG-3, VISTA, TIM-3, SIRPα, and OX40. We also highlight the unique dual role of VISTA and SIRPα in modulating immune responses under specific conditions, and explore potential immunotherapeutic pathways tailored to the distinct characteristics of different immune checkpoint proteins. These insights into the unique advantages of checkpoint proteins provide new directions for drug discovery, emphasizing that emerging immune checkpoint molecules could serve as targets for novel therapies in cancer, autoimmune diseases, infectious diseases, and transplant rejection.

Multifaceted functions of tissue-resident memory T cells in tumorigenesis and cancer immunotherapy

Tissue-resident memory T (TRM) cells are well reported as a strong protective first line of defense against foreign antigens in non-lymphoid tissues. Moreover, TRM cells have demonstrated critical protective roles in antitumor immunity, contributing to enhanced survival and tumor growth inhibition across various cancer types. However, surprisingly, recent studies suggest that TRM cells can exhibit paradoxical effects, potentially promoting tumor progression under certain conditions and leading to adverse outcomes during antitumor immune responses. Understanding the complexities of TRM cell functions will enable us to harness their potential in advancing cancer immunotherapy more effectively. Therefore, this review comprehensively investigates the dual roles of TRM cells in different tumor contexts, highlighting their protective functions in combating cancers and their unfavorable potential to exacerbate tumor development. Additionally, we explore the implications of TRM cell behaviors for future cancer treatment strategies, emphasizing the need for further research to optimize the therapeutic exploitation of TRM cells while mitigating their deleterious effects.

Expanding horizons of cancer immunotherapy: hopes and hurdles

Background

Tumor displays various forms of tumor heterogeneity including immune heterogeneity that allow cancer cells to survive during conventional anticancer drug interventions. Thus, there is a strong rationale for overcoming anticancer drug resistance by employing the components of immune cells. Using the immune system to target tumor cells has revolutionized treatment. Recently, significant progress has been achieved at preclinical and clinical levels to benefit cancer patients.

Approach

A review of literature from the past ten years across PubMed, Scopus, and Web of Science focused on immunotherapy strategies. These include immune checkpoint inhibitors (ICIs), tumor-infiltrating lymphocyte therapy, antibody-drug conjugates (ADCs), cancer vaccines, CAR T-cell therapy, and the role of the gut microbiome.

Conclusion

While immunotherapy outcomes have improved, particularly for tumor types such as melanoma and non-small cell lung cancer (NSCLC), challenges persist regarding predictive biomarker identification and better management. Ongoing research on modifiers of immune function like gut microbiome-derived metabolites, next-generation ADCs, and new classes of biologics is warranted. Overall, continued investigation toward optimizing synergistic immunotherapeutic combinations through strategic drug delivery systems is imperative for preclinical and clinical success in cancer patients.

Reprogramming the breast tumor immune microenvironment: cold-to-hot transition for enhanced immunotherapy

This review discusses reprogramming the breast tumor immune microenvironment from an immunosuppressive cold state to an immunologically active hot state. A complex interplay is revealed, in which the accumulation of metabolic byproducts-such as lactate, reactive oxygen species (ROS), and ammonia-is shown to impair T-cell function and promote tumor immune escape. It is demonstrated that the tumor microenvironment (TME) is dominated by immunosuppressive cytokines, including interleukin-10 (IL-10), transforming growth factorβ (TGFβ), and IL-35. Notably, IL-35 is produced by regulatory T cells and breast cancer cells. The conversion of conventional T cells into IL-35-producing induced regulatory T cells, along with the inhibition of pro-inflammatory cytokine secretion, contributes to the suppression of anti-tumor immunity. It is further demonstrated that key immune checkpoint molecules-such as PD-1, PDL1, CTLA-4, TIM-3, LAG-3, and TIGIT-are upregulated within the TME, leading to Tcell exhaustion and diminished immune responses. The blockade of these checkpoints is shown to restore T-cell functionality and is proposed as a strategy to convert cold tumors into hot ones with robust effector cell infiltration. The therapeutic potential of chimeric antigen receptor (CAR)T cell therapy is also explored, and targeting specific tumor-associated antigens, such as glycoproteins and receptor tyrosine kinases, is highlighted. It is suggested that CART cell efficacy can be enhanced by combining these cells with immune checkpoint inhibitors and other immunomodulatory agents, thereby overcoming the barriers imposed by the immunosuppressive TME. Moreover, the role of the microbiome in regulating estrogen metabolism and systemic inflammation is reviewed. Alterations in the gut microbiota are shown to affect the TME, and microbiome-based interventions are proposed as an additional means to facilitate the cold-to-hot transition. It is concluded that by targeting the metabolic and immunological pathways that underpin immune suppression-through combination strategies involving checkpoint blockade, CART cell therapies, and microbiome modulation-the conversion of the breast TME from cold to hot can be achieved. This reprogramming is anticipated to enhance immune cell infiltration and function, thereby improving the overall efficacy of immunotherapies and leading to better clinical outcomes for breast cancer patients.

New Therapeutic Targets TIGIT, LAG-3 and TIM-3 in the Treatment of Advanced, Non-Small-Cell Lung Cancer

The introduction of immunotherapy and target therapy into clinical practice has become a chance for many patients with cancer to prolong their survival while maintaining optimal quality of life. Treatment of lung cancer is excellent evidence of the progress of medical therapies. An understanding of the mechanisms of tumor development has led to the evolution of new methods of treatment. Immunoreceptors of T cells with the immunoglobulin domain ITIM, TIM-3 (T-cell immunoglobulin- and mucin domain-3-containing molecule 3), and LAG-3 (lymphocyte activation gene-3) represent new interesting therapeutic targets. The combination of anti-PD-1 and anti-CTLA-4 blockade has proven the possibility of strengthening the anti-tumor response by acting via two separate mechanisms. Adding additional checkpoints to the PD-1 blockade offers hope for further improvements in the effects of the treatment of patients and expanding the group responding to immunotherapy. This paper presents new promising molecular targets along with studies demonstrating the treatment results using them.

Expression of the TIGIT axis and the CD39/CD73 purinergic pathway in bone metastasis-derived immune cells

BACKGROUND

Bone metastases (BM) represent one of the most common sites of metastasis. The study aimed to compare the composition of immune cell infiltration from aspirates of different BM prior to systemic therapy.

METHOD

Phenotypic and functional analyses were conducted via multiparametric flow cytometry (MFC) on BM-derived aspirates obtained from patients with breast cancer (BC, n = 6), patients with prostate cancer (PC, n = 5), patients with non-small-cell lung cancer (NSCLC) (n = 7), patients with myeloma (MM, n = 10) and bone aspirates from age-matched non-malignant controls (NMC, n = 10).

RESULTS

Across all tumors aspirates the fraction of CD8+ T cells was reduced. In contrast, infiltration by immunosuppressive CD56+CD16-NK and CD163+CD86+ M2-like macrophages was increased in BM compared to NMC aspirates. BM-derived CD8+ T cells aberrantly co-expressed TIGIT with PVRIG or CD39. Similarly, BM-derived cytotoxic NK cells co-expressed TIGIT and PVRIG. In addition, BM-derived M2-like macrophages exhibited an increased subset of cells co-expressing either TIGIT and PVRL4 or CD112 and CD155. Using a myeloma model, functional in vitro studies showed that blockade of TIGIT and CD39 leads to increased PBMC-mediated lysis of myeloma cells.

CONCLUSION

The study shows that an altered immune cell composition is present in BM across the different tumor entities. Additionally, molecules of the TIGIT checkpoint as well as of the purinergic pathway are aberrantly expressed by BM-infiltrating CD8+ T cells, NK cells and macrophages and also functionally relevant for tumor cell lysis.

Multi-omics identification of a polyamine metabolism related signature for hepatocellular carcinoma and revealing tumor microenvironment characteristics

Background

Accumulating evidence indicates that elevated polyamine levels are closely linked to tumor initiation and progression. However, the precise role of polyamine metabolism in hepatocellular carcinoma (HCC) remains poorly understood.

Methods

We conducted differential expression analysis on bulk RNA sequencing data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) to identify 65 polyamine metabolism-related genes. By employing unsupervised consensus clustering, AddModuleScore, single-sample gene set enrichment analysis (ssGSEA), and weighted gene co-expression network analysis (WGCNA), we identified polyamine metabolism-related genes at both the bulk RNA-seq and single-cell RNA-seq (scRNA-seq) levels. Utilizing 101 machine learning algorithms, we constructed a polyamine metabolism-related signature (PMRS) and validated its predictive power across training, testing, and external validation cohorts. Additionally, we developed a prognostic nomogram model by integrating PMRS with clinical variables. To explore immune treatment sensitivity, we assessed tumor mutation burden (TMB), tumor immune dysfunction and exclusion (TIDE) score, mutation frequency, and immune checkpoint genes expression. Immune cell infiltration was analyzed using the CIBERSORT algorithm. Finally, RT-qPCR experiments were conducted to validate the expression of key genes.

Results

Using 101 machine learning algorithms, we established a polyamine metabolism-related signature comprising 9 genes, which exhibited strong prognostic value for HCC patients. Further analysis revealed significant differences in clinical features, biological functions, mutation profiles, and immune cell infiltration between high-risk and low-risk groups. Notably, TIDE analysis and immune phenotype scoring (IPS) demonstrated distinct immune treatment sensitivities between the two risk groups. RT-qPCR validation confirmed that these 9 genes were highly expressed in normal cells but significantly downregulated in tumor cells.

Conclusions

Our study developed a polyamine metabolism-based prognostic risk signature for HCC, which may provide valuable insights for personalized treatment strategies in HCC patients.

Immune-Based Therapies in Pancreatic Cancer: a Systematic Review of Ongoing Clinical Trials (2020-2022)

INTRODUCTION

Immune-based treatment strategies have emerged across solid organ malignancies largely with the development of immune checkpoint inhibitors. To date, these strategies have not improved clinical outcomes in pancreatic ductal adenocarcinoma (PDAC).

METHODS

Here, we perform a systematic review to summarize available evidence for recent immune-based treatment strategies in PDAC. We analyze trends in activated clinical trials queried from clinicaltrials.gov in the years 2020-2022. We review study design, sponsorship, and trends in the phase of development. There is a growing emergence of multiple new classes of immune-based targets and combination strategies in early-phase development.

RESULTS

Immune-based clinical trials in PDAC are highly collaborative including primarily stakeholders in government, industry, and academic medical centers. In this period, a majority of trials have integrated a non-randomized design (83.2%), including a trend towards an increase in Phase I/II clinical trials. This analysis found a growing list of studies using combinations including inhibitors of vascular endothelial growth factors (VEGF), an expanded set of vaccine-based strategies, and the use of Bispecific T-Cell Engagers (BiTEs). Immune checkpoint inhibitors have been a mainstay of combination strategies including the use of new immune checkpoint inhibitors (CD40, TIGIT).

CONCLUSION

Immune-based strategies in PDAC have expanded across new targets and the complexities of combinatory approaches. Integrating this work across key stakeholders remains of critical importance to improve clinical outcomes.

CD155 blockade enhances allogeneic natural killer cell-mediated antitumor response against osteosarcoma

BACKGROUND

Allogeneic bone marrow transplant (alloBMT) is curative for hematologic malignancies through the graft-versus-tumor (GVT) effect but has been ineffective for solid tumors like osteosarcoma (OS). OS expresses CD155 which interacts strongly with inhibitory receptors TIGIT and CD96 but also binds to activating receptor DNAM-1 on natural killer (NK) cells. CD155 has never been targeted after alloBMT. Combining adoptively transferred allogeneic NK (alloNK) cells with CD155 blockade after alloBMT may enhance a GVT effect against OS.

METHODS

Murine NK cells were activated and expanded ex vivo with superagonist interleukin (IL)-15/IL-15Rα. AlloNK and syngeneic NK (synNK) cell phenotype, cytotoxicity, cytokine production, and degranulation against CD155-expressing murine OS cell line K7M2 were assessed in vitro. Mice bearing pulmonary OS metastases underwent alloBMT and alloNK cell infusion with anti-CD155 either before or after tumor induction, with select groups receiving anti-DNAM-1 pretreated alloNK cells. Tumor growth, graft-versus-host disease and survival were monitored, and differential gene expression of lung tissue was assessed by RNA microarray.

RESULTS

AlloNK cells exhibited superior cytotoxicity against CD155-expressing OS compared with synNK cells, and this activity was enhanced by CD155 blockade. CD155 blockade increased alloNK cell degranulation and interferon gamma production through DNAM-1. In vivo, CD155 blockade with alloNK infusion increased survival when treating OS that relapsed after alloBMT. No benefit was seen for treating established OS before alloBMT. Combining CD155 and anti-DNAM-1 pretreated alloNK did not affect survival and tumor control benefits seen with CD155 blockade alone. RNA microarray showed mice treated with alloNK and CD155 blockade had increased expression of cytotoxicity genes and the NKG2D ligand H60a, whereas mice treated with anti-DNAM-1 pretreated alloNK cells resulted in upregulation of NK cell inhibitory receptor genes. Whereas blocking DNAM-1 on alloNK abrogated cytotoxicity, blocking NKG2D had no effect, implying DNAM-1:CD155 engagement drives alloNK activation against OS.

CONCLUSIONS

These results demonstrate the safety and efficacy of infusing alloNK cells with CD155 blockade to mount a GVT effect against OS and show benefits are in part through DNAM-1. Defining the hierarchy of receptors that govern alloNK responses is critical to translating alloNK cell infusions and immune checkpoint inhibition for solid tumors treated with alloBMT.

Anti-TIGIT inhibitors plus PD-1 or PD-L1 inhibitors versus PD-1 or PD-L1 inhibitors for first-line treatment of advanced non-small cell lung cancer

OBJECTIVES

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To evaluate the effectiveness and safety of anti-TIGIT inhibitors in combination with PD-1 inhibitors or PD-L1 inhibitors compared to treatment with PD-1 inhibitors or PD-L1 inhibitors in the first-line treatment of advanced NSCLC. To assess the effectiveness and safety of anti-TIGIT inhibitors in combination with chemotherapy and PD-1 inhibitors or PD-L1 inhibitors compared to treatment with chemotherapy plus PD-1 inhibitors or PD-L1 inhibitors in the first-line treatment of advanced NSCLC.

Targeting the poliovirus receptor to activate T cells and induce myeloid-derived suppressor cells to differentiate to pro-inflammatory macrophages via the IFN-γ-p-STAT1-IRF8 axis in cancer therapy

T cell immunoglobulin and ITIM domain (TIGIT) is one of the most important immune checkpoints expressed on lymphocytes, and poliovirus receptor (PVR, also CD155) serves as the most crucial ligand for TIGIT, harboring an important function in cancer cells and influencing the tumor microenvironment (TME). While it's well-established that TIGIT blockade could reverse immunosuppression, the question of whether direct inhibition of PVR yields comparable results remains to be fully elucidated. This study investigated the role of PVR within the TME on the LLC, CT26 and MC38 tumor models and found that direct blockade of PVR on tumor cells could trigger T cell activation, enhance the production of immunostimulatory cytokine IFN-γ, and drive the differentiation of intratumoral myeloid-derived suppressor cells (MDSCs) into pro-inflammatory macrophages through the IFN-γ-p-STAT1-IRF8 axis. Furthermore, this study found that the anti-PVR nanobody monotherapy reduced tumor volume in the CT26 and MC38 tumor models. Combination of anti-PVR nanobody and anti-PD-1 antibody was effective in the LLC, CT26 and MC38 tumor models and had acceptable toxicity. These findings collectively suggest that PVR exhibits considerable promise as a therapeutic target in the development of immunotherapies aimed at augmenting the anti-tumor immune response.

Natural killer cells: the immune frontline against circulating tumor cells

Natural killer (NK) play a key role in controlling tumor dissemination by mediating cytotoxicity towards cancer cells without the need of education. These cells are pivotal in eliminating circulating tumor cells (CTCs) from the bloodstream, thus limiting cancer spread and metastasis. However, aggressive CTCs can evade NK cell surveillance, facilitating tumor growth at distant sites. In this review, we first discuss the biology of NK cells, focusing on their functions within the tumor microenvironment (TME), the lymphatic system, and circulation. We then examine the immune evasion mechanisms employed by cancer cells to inhibit NK cell activity, including the upregulation of inhibitory receptors. Finally, we explore the clinical implications of monitoring circulating biomarkers, such as NK cells and CTCs, for therapeutic decision-making and emphasize the need to enhance NK cell-based therapies by overcoming immune escape mechanisms.

The role of immune checkpoints PD-1 and CTLA-4 in cardiovascular complications leading to heart failure

Immune checkpoints, such as PD-1 and CTLA-4, are crucial regulators of immune responses, acting as gatekeepers to balance immunity against foreign antigens and self-tolerance. These checkpoints play a key role in maintaining cardiac homeostasis by preventing immune-mediated damage to critical organs like the heart. In this study, we explored the involvement of PD-1 and CTLA-4 in cardiovascular complications, particularly atherosclerosis and myocarditis, which can lead to heart failure. We conducted a comprehensive analysis using animal models and clinical data to assess the effects of immune checkpoint inhibition on cardiac function. Our findings indicate that disruption of PD-1 and CTLA-4 pathways exacerbates myocardial inflammation, accelerates atherosclerotic plaque formation, and promotes the development of heart failure. Additionally, we observed that immune checkpoint inhibition in these models led to increased infiltration of T lymphocytes, higher levels of pro-inflammatory cytokines, and enhanced tissue damage. These results suggest that PD-1 and CTLA-4 are critical in preserving cardiac health, and their inhibition can result in severe cardiovascular toxicity. Our study emphasizes the need for careful monitoring of cardiovascular health in patients undergoing immune checkpoint inhibitor therapies.

The Role of NK Cells in Cancer Immunotherapy: Mechanisms, Evasion Strategies, and Therapeutic Advances

Background/Objectives: Natural killer (NK) cells play a crucial role in tumor surveillance by exerting cytotoxic activity and modulating immune responses. However, tumors employ diverse evasion strategies that limit NK cell effectiveness. This review aims to explore the molecular mechanisms of NK cell activation and inhibition in cancer, the influence of the tumor microenvironment, and the latest advancements in NK cell-based immunotherapies, including adoptive NK cell transfer and Chimeric Antigen Receptor-Natural Killer (CAR-NK) cell therapies. Methods: A comprehensive literature review was conducted, prioritizing peer-reviewed studies from the last decade on NK cell biology, tumor immune evasion, and immunotherapeutic applications. The analysis includes data from preclinical models and clinical trials evaluating NK cell expansion strategies, cytokine-based stimulation, and CAR-NK cell therapy developments. Results: NK cells eliminate tumors through cytotoxic granule release, death receptor pathways, and cytokine secretion. However, tumor cells evade NK-mediated immunity by downregulating activating ligands, secreting immunosuppressive molecules, and altering the tumor microenvironment. Novel NK cell-based therapies, such as CAR-NK cells and combination approaches with immune checkpoint inhibitors, enhance NK cell persistence and therapeutic efficacy against both hematologic and solid malignancies. Clinical trials suggest improved safety profiles compared to CAR-T therapies, with reduced cytokine release syndrome and graft-versus-host disease. Conclusions: While NK cell-based immunotherapies hold great promise, challenges remain, including limited persistence and tumor-induced immunosuppression. Addressing these hurdles will be critical for optimizing NK cell therapies and advancing next-generation, off-the-shelf immunotherapeutics for broader clinical applications.

Immune Checkpoint Molecules: A Review on Pathways and Immunotherapy Implications

BACKGROUND

Today, treating cancer patients with monoclonal antibodies (mAbs), by targeting immune checkpoints, is one of the most outstanding immunotherapeutic methods. Immune checkpoints are special molecules having regulatory role in immune system responses. Once these molecules are presented on cancer cells, these cells will be capable of evading the immune system through their own specific pathways. This Evasion can be prevented by counterbalancing immune system responses with immune checkpoints related antibodies.

AIMS

The current study aimed to highlight immunotherapy and its methods, describe the immune checkpoints pathways, outline the immune checkpoint inhibitors (ICIs), and recent advances in this field, and sketch an outlook on the best treatment options for the most prevalent cancers.

MATERIALS & METHODS

This research implemented a narrative review method. A comprehensive literature review on the history, molecular and cellular biology, and the clinical aspects of immune checkpoint molecules was performed to illustrate the pathways involved in various cancers. Also, currently-available and future potential immunotherapies targeting these pathways were extracted from the searched studies.

RESULTS

The immune checkpoint family consists of many molecules, including CTLA-4, PD-1, PD-L1, LAG-3, TIM-3, and TIGIT. Attempts to modify these molecules in cancer treatment led to the development of therapeutic monoclonal antibodies. Most of these antibodies have entered clinical studies and some of them have been approved by the Food and Drug Administration (FDA) to be used in cancer patients' treatment plans.

DISCUSSION

With these novel treatments and the combination therapies they offer, there is also hope for better treatment outcomes for the previously untreatable metastatic cancers. In spite of the beneficial aspects of immune checkpoint therapy, similar to other treatments, they may cause side effects in some patients. Therefore, more studies are needed to reduce the probable side effects and uncover their underlying mechanism.

CONCLUSION

Based on the data shown in this review, there is still a lack of knowledge about the complete properties of ICIs and the possible combination therapies that we may be able to implement to achieve a better treatment response in cancer patients.

Heterogeneity of γδ T-cell subsets and their clinical correlation in patients with AML

Background

γδ T cells are integral elements of the immune system and have shown therapeutic potential in the treatment of acute myeloid leukemia (AML). Nevertheless, the influence of distinct functional subsets, including the activating marker NKG2D, the immune exhaustion marker TIGIT, and the regulatory marker Foxp3, on therapeutic outcomes in AML patients remains unknown.

Methods

First, we analyzed RNA-seq data from 167 patients in The Cancer Genome Atlas (TCGA) database, concentrating on the correlations between NKG2D, TIGIT, and Foxp3 gene expressions and their association with prognosis in AML. We employed flow cytometry to assess the expression of these molecular markers on γδ T cells and the Vδ1/Vδ2 subsets in the peripheral blood of 25 de novo AML (AML-DN) patients, 15 patients in complete remission (CR), and 27 healthy controls (HCs). We also analyzed the relationship between the expression frequencies of NKG2D, TIGIT, and Foxp3 on γδ T cells and their subsets, and their clinical outcomes.

Results

Based on data from TCGA database, we found that a high expression level of NKG2D in combination with a low expression level of TIGIT was significantly associated with longer overall survival (OS) in AML patients. Clinical data revealed that γδ T cells from AML-DN patients exhibited higher expression levels of TIGIT and Foxp3, whereas NKG2D expression was lower compared to that of HCs. Notably, the expression of the NKG2D+TIGIT- Vδ1 subset was significantly reduced in AML-DN patients compared to CR patients. Univariate logistic regression and Cox regression analyses further indicated that a high expression of the NKG2D+TIGIT- Vδ1 subset was associated with better clinical prognosis.

Conclusion

This study indicates that NKG2D+TIGIT- Vδ1 T cells are strongly correlated with improved prognosis in AML, and future research should investigate their potential in adoptive immunotherapy to advance more personalized and precise treatment strategies.

Overcoming immunotherapy resistance in glioblastoma: challenges and emerging strategies

Glioblastoma (GBM) is the most common and aggressive primary brain tumor in adults, characterized by rapid proliferation, extensive infiltration, and significant intratumoral heterogeneity. Despite advancements in conventional treatments, including surgery, radiotherapy, and chemotherapy, the prognosis for GBM patients remains poor, with a median survival of approximately 15 months. Immunotherapy has emerged as a promising alternative; however, the unique biological and immunological features, including its immunosuppressive tumor microenvironment (TME) and low mutational burden, render it resistant to many immunotherapeutic strategies. This review explores the key challenges in GBM immunotherapy, focusing on immune evasion mechanisms, the blood-brain barrier (BBB), and the TME. Immune checkpoint inhibitors and CAR-T cells have shown promise in preclinical models but have limited clinical success due to antigen heterogeneity, immune cell exhaustion, and impaired trafficking across the BBB. Emerging strategies, including dual-targeting CAR-T cells, engineered immune cells secreting therapeutic molecules, and advanced delivery systems to overcome the BBB, show potential for enhancing treatment efficacy. Addressing these challenges is crucial for improving GBM immunotherapy outcomes.

Future perspectives on immunotherapy for hepatocellular carcinoma

In recent years, several global phase III trials have shown that combinations of immune checkpoint inhibitors (ICIs) offer superior efficacy and survival compared to multi-kinase inhibitors, establishing them as the gold standard for treating patients with advanced hepatocellular carcinoma (HCC). This success has led to investigations into expanding the use of immunotherapy into various other settings and populations, including neoadjuvant and adjuvant therapies, patients with decompensated liver function and those awaiting liver transplantation. Despite its proven efficacy, a significant number of patients still develop resistance to immunotherapy, highlighting the need for innovative strategies to address this challenge. Approaches aimed at enhancing tumour immunogenicity, such as combining immunotherapy with transarterial chemoembolization or radiation therapies, show significant promise. Additionally, novel immunotherapeutics - such as triplet therapy, bispecific antibodies, adoptive T-cell therapy and cancer vaccines - are in early development for HCC. These agents have demonstrated potential for synergistic effects with existing ICIs, with initial studies yielding positive outcomes. In this review, we offer our future perspective on immunotherapy, emphasizing emerging indications, novel combination strategies and the development of new immunotherapeutic agents. Overall, the future of immunotherapy in HCC is brimming with extraordinary potential, set to transform the treatment landscape and redefine the possibilities for managing this challenging disease.

Emerging immunotherapies in osteosarcoma: from checkpoint blockade to cellular therapies

Osteosarcoma remains a highly aggressive bone malignancy with limited therapeutic options, necessitating novel treatment strategies. Immunotherapy has emerged as a promising approach, yet its efficacy in osteosarcoma is hindered by an immunosuppressive tumor microenvironment and resistance mechanisms. This review explores recent advancements in checkpoint blockade, cellular therapies, and combination strategies aimed at enhancing immune responses. We highlight key challenges, including tumor heterogeneity, poor immune infiltration, and the need for predictive biomarkers. By integrating immunotherapy with chemotherapy, radiotherapy, and targeted therapy, emerging approaches seek to improve treatment outcomes. This review provides a comprehensive analysis of the evolving landscape of osteosarcoma immunotherapy, offering insights into future directions and potential breakthroughs. Researchers and clinicians will benefit from understanding these developments, as they pave the way for more effective and personalized therapeutic strategies in osteosarcoma.

Single-cell atlas of the pregnant equine endometrium before and after implantation†

Embryo implantation in the mare occurs just over one month after fertilization, coinciding with the production of chorionic gonadotropin. The factors that regulate this late implantation in the mare, and whether they are unique to horses or shared with more invasive embryo implantation in other species, remain poorly understood. This study aimed to determine and compare the transcriptome and subpopulations of endometrial cells before and after embryo implantation in the horse. Single-cell RNA sequencing was used to characterize the transcriptome of nearly 97,000 endometrial cells collected from biopsies of the endometrium at the beginning (day 33 of gestation) and after embryo implantation (day 42 of gestation) in mares. Sixteen immune and 24 non-immune cell clusters were identified, representing known major cell populations as well as novel subpopulations of horse immune cells such as resident innate lymphoid cells and mucosal-associated invariant T cells. Contrary to current knowledge, endometrial natural killer (eNK) cells were the most abundant endometrial leukocyte population during implantation in horses. Moreover, eNK cells not only expressed genes that may interact with fetal MHC I, such as LY49F, but also exert immunoregulatory functions independent of MHC I expression, such as CD96/TIGIT. Analogous to other species studied, upregulation of CXCR4 was found in several subpopulations of immune cells. Our results suggest that despite distinctive and later placentation compared with humans, horses share some key similarities in the mechanisms of embryo implantation.

QRICH1 mediates an intracellular checkpoint for CD8+ T cell activation via the CARD11 signalosome

Antigen receptor signaling pathways that control lymphocyte activation depend on signaling hubs and negative regulatory proteins to fine-tune signaling outputs to ensure host defense and avoid pathogenic responses. Caspase recruitment domain-containing protein 11 (CARD11) is a critical signaling scaffold that translates T cell receptor (TCR) triggering into the activation of nuclear factor κB (NF-κB), c-Jun N-terminal kinase (JNK), mechanistic target of rapamycin (mTOR), and Akt. Here, we identify glutamine-rich protein 1 (QRICH1) as a regulator of CARD11 signaling that mediates an intracellular checkpoint for CD8+ T cell activation. QRICH1 associates with CARD11 after TCR engagement and negatively regulates CARD11 signaling to NF-κB. QRICH1 binding to CARD11 is controlled by an autoregulatory intramolecular interaction between QRICH1 domains of previously uncharacterized function. QRICH1 controls the antigen-induced activation, proliferation, and effector status of CD8+ T cells by regulating numerous genes critical for CD8+ T cell function. Our results define a component of antigen receptor signaling circuitry that fine-tunes effector output in response to antigen recognition.

Impact of cannabinoids on cancer outcomes in patients receiving immune checkpoint inhibitor immunotherapy

Cannabinoids relieve pain, nausea, anorexia and anxiety, and improve quality of life in several cancer patients. The immunotherapy with checkpoint inhibitors (ICIs), although very successful in a subset of patients, is accompanied by moderate to severe immune-related adverse events (ir-AE) that often necessitate its discontinuation. Because of their role in symptomatic relief, cannabinoids have been used in combination with immune checkpoint inhibitor (ICI) immunotherapy. A few studies strongly suggest that the use of medicinal cannabis in cancer patients attenuates many of the ir-AE associated with the use of ICI immunotherapy and increase its tolerability. However, no significant beneficial effects on overall survival, progression free survival or cancer relapses were observed; rather, some of the studies noted adverse effects of concurrent administration of cannabinoids with ICI immunotherapy on the clinical benefits of the latter. Because of cannabinoids' well documented immunosuppressive effects mediated through the cannabinoid recptor-2 (CB2), we propose considering this receptor as an inhibitory immune checkpoint per se. A simultaneous neutralization of CB2, concurrent with cannabinoid treatment, may lead to better clinical outcomes in cancer patients receiving ICI immunotherapy. In this regard, cannabinoids such as cannabidiol (CBD) and cannabigerol (CBG), with little agonism for CB2, may be better therapeutic choices. Additional strategies e.g., the use of monoacylglycerol lipase (MAGL) inhibitors that degrade some endocannabinoids as well as lipogenesis and formation of lipid bilayers in cancer cells may also be explored. Future studies should take into consideration gut microbiota, CYP450 polymorphism and haplotypes, cannabinoid-drug interactions as well as genetic and somatic variations occurring in the cannabinoid receptors and their signaling pathways in cancer cells for personalized cannabis-based therapies in cancer patients receiving ICIs. This may lead to rational knowledge-based regimens tailored to individual cancer patients.

Exploring the role of TIGIT in patients with Small Cell Lung Cancer as a novel predictor of prognosis and immunotherapy response

BACKGROUND

T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT) is a novel immune checkpoint playing a crucial role in immunosuppression and immune evasion. This study aims to elucidate the expression patterns, characteristics, and possible mechanisms of TIGIT in small cell lung cancer (SCLC).

METHODS

TIGIT expression was analyzed across various cancers and normal tissues using The Cancer Genome Atlas (TCGA). Transcriptomic data from SCLC patients, sourced from the Gene Expression Omnibus (GEO) and literature, were analyzed to assess TIGIT-related characteristics. Immunohistochemistry (IHC) was used to verify TIGIT expression in post-surgical and advanced SCLC samples, focusing on expression characteristics, prognostic value, and treatment response.

RESULTS

TIGIT was significantly overexpressed in various tumors, including SCLC (p < 0.05). Higher expression was associated with better overall survival (OS) (p < 0.05). Notably, a significant positive correlation was observed between TIGIT expression and immune-related metagenes, such as HCK, interferon, and LCK (p < 0.05). Immune infiltration analysis revealed a strong positive correlation between TIGIT expression and immune score in multiple cohorts. Additionally, TIGIT expression correlated positively with immune cells, including CD8 T cells, cytotoxic lymphocytes, and B cells (p < 0.05), and multiple immune checkpoints like BTLA, ICOS, and LAG3 (p < 0.05), while it had a significant negative correlation with the TIDE score (p < 0.05). In the validation section, patients with high TIGIT expression showed significantly prolonged disease-free survival (DFS) and OS (p < 0.05), and demonstrated a better response to adjuvant chemotherapy (ACT) and immunotherapy.

CONCLUSION

TIGIT serves as a biomarker in SCLC, with its high expression indicating favorable prognosis and treatment response. These effects may be due to TIGIT's unique immune landscape and its association with other immune checkpoints.

Treg fitness signatures as a biomarker for disease activity in Juvenile Idiopathic Arthritis

Juvenile Idiopathic Arthritis (JIA) is an autoimmune condition characterised by flares of joint inflammation. However, no reliable biomarker exists to predict the erratic disease course. Normally, regulatory T cells (Tregs) maintain tolerance, with altered Tregs associated with autoimmunity. Treg signatures have shown promise in monitoring other conditions, therefore a Treg gene/protein signature could offer novel biomarker potential for predicting disease activity in JIA. Machine learning on our nanoString Treg 48-gene signature on peripheral blood (PB) Tregs generated a model to distinguish active JIA (active joint count, AJC≥1) Tregs from healthy controls (HC, AUC = 0.9875 on test data). Biomarker scores from this model successfully differentiated inactive (AJC = 0) from active JIA PB Tregs. Moreover, scores correlated with clinical activity scores (cJADAS), and discriminated subclinical disease (AJC = 0, cJADAS≥0.5) from remission (cJADAS<0.5). To investigate altered protein expression as a surrogate measure for Treg fitness in JIA, we utilised spectral flow cytometry and unbiased clustering analysis. Three Treg clusters were of interest in active JIA PB, including TIGIThighCD226highCD25low Teff-like Tregs, CD39-TNFR2-Helioshigh, and a 4-1BBlowTIGITlowID2intermediate Treg cluster predominated in inactive JIA PB (AJC = 0). The ratio of these Treg clusters correlated to cJADAS, and higher ratios could potentially predict inactive individuals that flared by 9-month follow-up. Thus, we demonstrate altered Treg signatures and subsets as an important factor, and useful biomarker, for disease progression versus remission in JIA, revealing genes and proteins contributing to Treg fitness. Ultimately, PB Treg fitness measures could serve as routine biomarkers to guide disease and treatment management to sustain remission in JIA.

TIGIT/PVR axis regulates anti-tumor immunity in hematologic malignancies

Hematologic malignancy stands as a grave form of cancer characterized by its arduous treatment and heightened likelihood of recurrence. Over the recent years, immunotherapy has progressively evolved into a pivotal approach for addressing hematologic malignancies. As a novel inhibitory receptor of NK and T cells, TIGIT is similar to PD-1, and blocking TIGIT can play a huge anti-tumor effect. At present, target TIGIT is still in clinical trials. Within this context, the TIGIT/PVR axis, serving as a pivotal element within the immunomodulatory framework, assumes a critical role in tumor immunity orchestration. This composition delves into the advancement of research concerning the TIGIT/PVR axis within hematologic malignancies, elucidating its mechanism for impeding anti-tumor immune responses. Furthermore, potential therapeutic avenues are explored, encompassing immunotherapeutic strategies aimed at targeting the TIGIT/PVR axis, alongside the conceivable integration with alternative immune checkpoint inhibitors. Ultimately, the paper encapsulates forthcoming research trajectories, aspiring to provide a compass for deeper comprehension of the TIGIT/PVR axis's role within hematologic malignancies, consequently fostering the creation of more potent immunotherapeutic tactics. This review details the therapeutic prospects of TIGIT in hematological malignancies, which is expected to advance research targeting TIGIT in hematological malignancies and bring hope for survival to these patients.

Integrative Bioinformatics Analysis and Experimental Study of NLRP12 Reveal Its Prognostic Value and Potential Functions in Ovarian Cancer

NLRP12 plays a significant role in cellular functional behavior and immune homeostasis, influencing inflammation, tumorigenesis, and prognosis. This study aimed to explore its specific effects on the tumor microenvironment (TME) and its contribution to heterogeneity in ovarian cancer (OV) through bioinformatics analysis and experimental verification. Utilizing various bioinformatics databases and clinical specimens, we investigated NLRP12 expression and its relationship with OV prognosis and immune infiltration. In vitro assays were conducted to assess the impact of NLRP12 on the proliferation and invasion of OV cells. Our findings indicate that NLRP12 is upregulated in OV, with high expression correlating with a negative prognosis. Furthermore, NLRP12 expression demonstrated a positive correlation with the infiltration of various immune cells and the expression of immune checkpoint molecules in OV. Analysis of The Cancer Immunome Atlas (TCIA) database revealed that OV patients with lower NLRP12 expression may exhibit an enhanced response to immunotherapy, particularly CTLA4 blockers, a finding validated in animal experiments. Additionally, the study emphasized the role of NLRP12 in influencing the prognosis of OV patients by promoting epithelial-mesenchymal transition (EMT) in ovarian cancer cells. Finally, we identified a potential therapeutic compound, Schisandrin B (Schi B), which decreases NLRP12 expression in ovarian cancer cells by binding to the transcription factor SPI1 associated with NLRP12. Our findings suggest that NLRP12 serves as a crucial immune-related biomarker predicting poor outcomes in OV, and targeting NLRP12 may represent a promising therapeutic approach for OV patients in the future.

The prognostic significance of epoxide hydrolases in colorectal cancer

Colorectal cancer (CRC) is a common malignant cancer. Epoxide hydrolases (EHs) are involved in the development of cancer by regulating epoxides, but their relationship with CRC is unclear. We used multiple datasets to confirm the expression of different EPHX family members in CRC tissues, and to explore their association with different clinicopathologic characteristics. The Kaplan-Meier method, correlation analysis and random forest algorithm were used to evaluate the prognostic value of EPHX family members for CRC. Finally, the cell experiment verified function of EPHX4 in CRC. The expressions of EPHX1 and EPHX2 were significantly decreased, while those of EPHX3 and EPHX4 were significantly increased in CRC. The expressions of EPHX family members were correlated with some clinicopathologic features and overall survival. The expressions of the EPHX family were positively associated with CD274, CTLA4, HAVCR2, and TIGIT. EPHX2 and EPHX4 were diagnostic and predictive biomarkers for CRC. EPHX4 promoted the malignant phenotype of CRC cells. Our study firstly elucidated the prognostic significance of EPHX family members in CRC and identified novel diagnostic and prognostic biomarkers for CRC.

Fc-competent TIGITx4-1BB bispecific antibody exerts potent long-lasting antitumor activity by potentiating CD8+ T cell activity and Fcγ receptor-mediated modulation of the tumor microenvironment

BACKGROUND

TIGIT was identified as a target immune checkpoint for overcoming resistance to PD-(L)1-blocking antibodies. However, the clinical efficacies of TIGIT antibodies were moderate in monotherapy and mixed in combination with PD-(L)1 antibodies. 4-1BB, a strong inducible costimulatory receptor, is another attractive target in antitumor therapeutics. This study investigated whether ABL112, an Fc-competent bispecific antibody targeting TIGIT and 4-1BB (TIGITx4-1BB), would enhance antitumor activity via Fcγ receptor (FcγR)-mediated macrophage activation and antibody-dependent cell-mediated functions.

METHODS

TIGIT-dependent 4-1BB activation and TIGIT-blocking activity were assessed using reporter Jurkat T cell lines expressing 4-1BB and TIGIT, respectively. In vivo antitumor activity was confirmed in h4-1BB knock-in mice. The main immune cell subsets associated with the antitumor activity of ABL112 were identified using antibodies for depleting specific immune cell subtypes or FcγR-blocking antibodies. The effects of a combined pembrolizumab or atezolizumab treatment with ABL112 were assessed in two mouse models with different genetic backgrounds. Statistical analysis was performed using one-way or two-way analysis of variance (ANOVA) with Dunnett's multiple-comparison test or one-way ANOVA with Fisher's multiple-comparison test.

RESULTS

ABL112 restored T cell activity by blocking TIGIT-CD155 interactions, based on a TIGIT blockade reporter assay. ABL112, an Fc-competent TIGITx4-1BB bispecific antibody, showed strong FcγRI-dependent 4-1BB activation along with TIGIT-dependent 4-1BB activation. In H22 tumor models expressing high levels of endogenous CD155, both ABL112 and parent TIGIT single-domain Ab showed potent tumor-suppressive activity; however, only ABL112 exerted long-lasting antitumor activity. ABL112 induced a marked decrease in Treg numbers, while augmenting the absolute number of CD8+ T cells and proportion of CD226+ CD8+ T cells. The expressions of CXCL10, CXCL11, IFN-γ, and TNF-α increased, indicating myeloid cell activation and potential modification of the tumor microenvironment to an inflammatory phenotype. ABL112 not only showed outstanding antitumor activity as a monotherapy, but also showed synergistic effects with PD-(L)1 mAb compared with the combined TIGIT-PD-(L)1 mAb treatments.

CONCLUSIONS

Through multiple mechanisms of action, ABL112 exerted potent tumor-killing activity and immune memory response alone or in combination with anti-PD-(L)1 therapies, representing a promising new cancer treatment strategy.

Deep analysis of the trials and major challenges in the first-line treatment for patients with extensive-stage small cell lung cancer

The median overall survival (OS) is approximately 10 months when chemotherapy alone is the first-line treatment for extensive-stage small cell lung cancer (ES-SCLC). The approval of the two PD-L1 inhibitors, atezolizumab and durvalumab, marked the beginning of the immunotherapy era for ES-SCLC. Serplulimab, as the first PD-1 inhibitor to achieve success in the first-line treatment of ES-SCLC, has not only demonstrated significant improvements in patient survival outcomes but also ushered in a new era for PD-1 inhibitors in the treatment of ES-SCLC. Recently, antiangiogenic agents with chemo-immunotherapy have achieved breakthroughs in first-line ES-SCLC treatment. Improving the clinical benefits of individualized treatment for patients with ES-SCLC remains challenging. Challenges include identifying biomarkers for targeted therapy, exploring new treatments, developing new medicines, and classifying SCLC molecular subtypes. This review provides an in-depth analysis of research on first-line ES-SCLC treatment. Additionally, it discusses advances in ES-SCLC treatment.

A combination of PD-1 and TIGIT immune checkpoint inhibitors elicits a strong anti-tumour response in mesothelioma

BACKGROUND

Finding effective and curative treatment for mesothelioma remains challenging. While the introduction of immunotherapy combinations using ipilimumab (anti-CTLA-4) and nivolumab (anti-PD-1) have offered hope for some patients, a large proportion of mesothelioma cases, particularly the epithelial subtype, have minimal benefit from this.

METHODS

Our study was inspired by the results of the AdvanTG-105 phase I clinical trial, which showed partial response with anti-TIGIT/PD-1 treatment in two epithelioid mesothelioma patients. Here, we conducted a comprehensive in vivo experiment involving eight animal treatment groups administered with either PBS (control group), cisplatin/pemetrexed, anti-PD-1, anti-PD-1 + anti-CTLA-4, anti-TIGIT, anti-PD-1 + anti-TIGIT, anti-PD-1 + anti-CTLA-4 + anti-TIGIT, and cisplatin/pemetrexed + anti-PD-1 + anti-TIGIT.

RESULTS

Our results indicate that animals receiving anti-PD-1 + TIGIT exhibited a superior anti-tumour response, with 90% of the treatment group exhibiting an objective response, compared to 60%, 20% and 40% for the standard-of-care anti-PD-1 + CTLA-4, single-agent anti-PD-1 and cisplatin/pemetrexed treatment groups, respectively. Animals receiving anti-PD-1 + TIGIT displayed a significantly reduced average tumour size, with improved weight and survival rates, and fewer adverse effects than those receiving anti-PD-1 + CTLA-4 treatment. Anti-PD-1 + TIGIT-treated animals achieved complete tumour regression, with heightened effector CD8 + T cell and NK cell activity, remaining tumour-free for over 300 days without immune-related adverse events. After initial tumour elimination, anti-PD-1 + TIGIT-treated animals showed no tumour regrowth in the rechallenge experiment.

CONCLUSION

These findings provide rationale for the development of an anti-PD-1 + TIGIT combination immunotherapy trial for mesothelioma patients.

Exploring lung cancer microenvironment: pathways and nanoparticle-based therapies

Lung cancer stands out as a significant global health burden, with staggering incidence and mortality rates primarily linked to smoking and environmental carcinogens. The tumor microenvironment (TME) emerges as a critical determinant of cancer progression and treatment outcomes, comprising a complex interplay of cells, signaling molecules, and extracellular matrix. Through a comprehensive literature review, we elucidate current research trends and therapeutic prospects, aiming to advance our understanding of TME modulation strategies and their clinical implications for lung cancer treatment. Dysregulated immune responses within the TME can facilitate tumor evasion, limiting the efficacy of immune checkpoint inhibitors (ICI). Consequently, TME modulation strategies have become potential avenues to enhance therapeutic responses. However, conventional TME-targeted therapies often face challenges. In contrast, nanoparticle (NP)-based therapies offer promising prospects for improved drug delivery and reduced toxicity, leveraging the enhanced permeability and retention (EPR) effect. Despite NP design and delivery advancements, obstacles like poor tumor cell uptake and off-target effects persist, necessitating further optimization. This review underscores the pivotal role of TME in lung cancer management, emphasizing the synergistic potential of immunotherapy and nano-therapy.

Divide and Conquer-Targeted Therapy for Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is the most aggressive and malignant type of breast cancer with limited treatment options and poor prognosis. One of the most significant impediments in TNBC treatment is the high heterogeneity of this disease, as highlighted by the detection of several molecular subtypes of TNBC. Each subtype is driven by distinct mutations and pathway aberrations, giving rise to specific molecular characteristics closely connected to clinical behavior, outcomes, and drug sensitivity. This review summarizes the knowledge regarding TNBC molecular subtypes and how it can be harnessed to devise tailored treatment strategies instead of blindly using targeted drugs. We provide an overview of novel targeted agents and key insights about new treatment modalities with an emphasis on the androgen receptor signaling pathway, cancer stem cell-associated pathways, phosphatidylinositol 3-kinase (PI3K)/AKT pathway, growth factor signaling, and immunotherapy.

Metabolic deficiencies underlie reduced plasmacytoid dendritic cell IFN-I production following viral infection

Type I Interferons (IFN-I) are central to host protection against viral infections, with plasmacytoid dendritic cells (pDC) being the most significant source, yet pDCs lose their IFN-I production capacity following an initial burst of IFN-I, resulting in susceptibility to secondary infections. The underlying mechanisms of these dynamics are not well understood. Here we find that viral infection reduces the capacity of pDCs to engage both oxidative and glycolytic metabolism. Mechanistically, we identify lactate dehydrogenase B (LDHB) as a positive regulator of pDC IFN-I production in mice and humans; meanwhile, LDHB deficiency is associated with suppressed IFN-I production, pDC metabolic capacity, and viral control following infection. In addition, preservation of LDHB expression is sufficient to partially retain the function of otherwise exhausted pDCs, both in vitro and in vivo. Furthermore, restoring LDHB in vivo in pDCs from infected mice increases IFNAR-dependent, infection-associated pathology. Our work thus identifies a mechanism for balancing immunity and pathology during viral infections, while also providing insight into the highly preserved infection-driven pDC inhibition.

Unleashing the Power of immune Checkpoints: A new strategy for enhancing Treg cells depletion to boost antitumor immunity

Regulatory T (Treg) cells, immunosuppressive CD4+ T cells, can impede anti-tumor immunity, complicating cancer treatment. Since their discovery, numerous studies have been dedicated to understand Treg cell biology, with a focus on checkpoint pathways' role in their generation and function. Immune checkpoints, such as PD-1/PD-L1, CTLA-4, TIGIT, TIM-3, and OX40, are pivotal in controlling Treg cell expansion and activity in the tumor microenvironment (TME), affecting their ability to suppress immune responses. This review examines the complex relationship between these checkpoints and Tregs in the TME, and how they influence tumor immunity. We also discuss the therapeutic potential of targeting these checkpoints to enhance anti-tumor immunity, including the use of immune checkpoint blockade (ICB) therapies and novel approaches such as CCR8-targeted therapies. Understanding the interaction between immune checkpoints and Treg cells can lead to more effective immunotherapeutic strategies, such as combining CCR8-targeted therapies with immune checkpoint inhibitors, to improve patient outcomes in cancer treatment.