Tim-3, a negative regulator of anti-tumor immunity

Immunotherapeutic strategies in pancreatic ductal adenocarcinoma (PDAC): current perspectives and future prospects

Pancreatic ductal adenocarcinoma (PDAC) is among the deadliest human malignancies with a dismal prognosis. During PDAC progression, the immune response is affected as cancer cells evade detection and elimination. Recently, there have been advances in the treatment of PDAC using immunotherapy, although a lot more work is yet to be done. In this review, we discuss these advances, challenges and potentials. We focus on existing and potential immune targets for PDAC, drugs used to target them, and some clinical trials conducted so far with them. Finally, novel targets in the tumour microenvironment such as stromal cells and other potential future areas to explore including bacterial therapy and the use of neoantigens in immunotherapy are highlighted.

Elevated serum levels of checkpoint molecules in patients with adult Still's disease

BACKGROUND

The interaction between galectin-9 (Gal-9) and its ligand, T cell immunoglobulin, and mucin-containing-molecule-3 (TIM-3), one of the coinhibitory receptors, transduce the inhibitory signaling to regulate immune responses. The dysregulated expression of checkpoint molecules has been reported under various inflammatory or autoimmune conditions. The aim of this study is to investigate the levels of these checkpoint molecules and their associations between proinflammatory markers in patients with adult Still's disease (ASD).

METHODS

Serum samples were collected from 47 patients with active ASD, 116 patients with rheumatoid arthritis (RA), and 37 healthy controls (HCs). Serum levels of Gal-9, soluble TIM-3 (sTIM-3), and IL-18 were determined using enzyme-linked immunosorbent assay (ELISA). Results were compared with the clinical features of ASD.

RESULTS

Serum Gal-9 levels in patients with ASD (median: 21.57 ng/ml, interquartile range IQR [11.41-39.72]) were significantly higher compared to those in patients with RA (7.58 ng/ml, IQR [5.57-10.20] p < 0.001) as well as those in HCs (4.51 ng/ml, [IQR; 3.58-5.45], p < 0.001). Similarly, serum sTIM-3 levels in patients with ASD were significantly higher than those in patients with RA and HCs. Serum levels of Gal-9 or sTIM-3 showed positive correlations with IL-18 levels (Gal-9; r = 0.90, p < 0.001, sTIM-3; r = 0.78, p < 0.001) in patients with ASD. Serum levels of Gal-9 or sTIM-3 correlated with serum ferritin (Gal-9; r = 0.77, p < 0.001, sTIM-3; r = 0.71, p < 0.001) and ASD disease activity score (Pouchot's score, Gal-9; r = 0.66, p < 0.001, sTIM-3; r = 0.59, p < 0.001), whereas there was no significant correlation between serum Gal-9 or sTIM-3 and CRP. ASD patients with chronic arthritis phenotype had a significantly higher Gal-9/ferritin and sTIM-3/ferritin ratio than those without this phenotype. After immunosuppressive treatment, Gal-9 and sTIM-3 levels showed a significant decline in parallel to the disease activity scores.

CONCLUSIONS

Serum levels of the coinhibitory checkpoint molecules were elevated and correlated with disease activity in patients with ASD. These coinhibitory checkpoint molecules may be implicated in the autoinflammatory process seen in ASD.

Role of Epigenetic Modifications in Inhibitory Immune Checkpoints in Cancer Development and Progression

A balance between co-inhibitory and co-stimulatory signals in the tumor microenvironment (TME) is critical to suppress tumor development and progression, primarily via maintaining effective immunosurveillance. Aberrant expression of immune checkpoints (ICs), including programmed cell death protein 1 (PD-1), cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), T cell immunoglobulin and mucin-domain containing-3 (TIM-3), lymphocyte-activation gene 3 (LAG-3) and T cell immunoreceptor with Ig and ITIM domains (TIGIT), can create an immune-subversive environment, which helps tumor cells to evade immune destruction. Recent studies showed that epigenetic modifications play critical roles in regulating the expression of ICs and their ligands in the TME. Reports showed that the promoter regions of genes encoding ICs/IC ligands can undergo inherent epigenetic alterations, such as DNA methylation and histone modifications (acetylation and methylation). These epigenetic aberrations can significantly contribute to the transcriptomic upregulation of ICs and their ligands. Epigenetic therapeutics, including DNA methyltransferase and histone deacetylase inhibitors, can be used to revert these epigenetic anomalies acquired during the progression of disease. These discoveries have established a promising therapeutic modality utilizing the combination of epigenetic and immunotherapeutic agents to restore the physiological epigenetic profile and to re-establish potent host immunosurveillance mechanisms. In this review, we highlight the roles of epigenetic modifications on the upregulation of ICs, focusing on tumor development, and progression. We discuss therapeutic approaches of epigenetic modifiers, including clinical trials in various cancer settings and their impact on current and future anti-cancer therapies.

Advances in Anti-Cancer Immunotherapy: Car-T Cell, Checkpoint Inhibitors, Dendritic Cell Vaccines, and Oncolytic Viruses, and Emerging Cellular and Molecular Targets

Unlike traditional cancer therapies, such as surgery, radiation and chemotherapy that are typically non-specific, cancer immunotherapy harnesses the high specificity of a patient’s own immune system to selectively kill cancer cells. The immune system is the body’s main cancer surveillance system, but cancers may evade destruction thanks to various immune-suppressing mechanisms. We therefore need to deploy various immunotherapy-based strategies to help bolster the anti-tumour immune responses. These include engineering T cells to express chimeric antigen receptors (CARs) to specifically recognise tumour neoantigens, inactivating immune checkpoints, oncolytic viruses and dendritic cell (DC) vaccines, which have all shown clinical benefit in certain cancers. However, treatment efficacy remains poor due to drug-induced adverse events and immunosuppressive tendencies of the tumour microenvironment. Recent preclinical studies have unveiled novel therapies such as anti-cathepsin antibodies, galectin-1 blockade and anti-OX40 agonistic antibodies, which may be utilised as adjuvant therapies to modulate the tumour microenvironment and permit more ferocious anti-tumour immune response.

Immune checkpoints in tumor microenvironment and their relevance to the development of cancer stem cells

Cancer is the second cause of mortality in the world after cardiovascular disease. Various studies attribute the emergence of therapeutic resistance in tumors to the presence of cancer stem cells or cancer-initiating cells (CSC/CIC). These relatively rare cells because of their typical stemness features, are responsible for tumor cell progression and recurrence. Moreover, CSCs have immunomodulatory capabilities and through orchestrating, some immunological profiles can stay safe from host anticancer immunity, and provide immunotherapy resistance in cancer patients. Many studies have shown that CSCs by producing immune system inhibitory factors and interacting with immune checkpoint molecules like CD47, PDL-1, CTLA4, Tim3, and LAG3, are able to communicate with tumor microenvironment (TME) components and protect cancer cells from immune clearance. In this review, we summarize the CSCs immunological mechanisms and comprehensively discuss interactions between these cells and factors that are present in the TME to repress immune system responses and enhance tumor survival. Therefore, it seems that further studies on this topic will open new doors to improve the therapeutic approaches of malignant cancers.

Comprehensive immunohistochemical analysis of immune checkpoint molecules in adult T cell leukemia/lymphoma

Acute or lymphomatous type adult T cell leukemia/lymphoma (ATLL) is an aggressive hematopoietic malignancy with poor prognosis. We previously reported that programmed cell death ligand 1 (PD-L1) expression could predict ATLL outcomes. However, the roles of other immune checkpoint molecules remain largely unknown in ATLL. Our aim in this study was to explore the clinicopathological impacts of immune checkpoint molecules in ATLL. Immunohistochemistry was performed in 69 ATLL patients with antibodies against the following: PD-L1, programmed cell death ligand 2 (PD-L2), OX40, OX40 ligand (OX40L), CD137, CD137 ligand (CD137L), Galectin-9, T cell immunoglobulin mucin-3 (Tim-3), cytotoxic T lymphocyte associated protein-4 (CTLA-4), lymphocyte activating-3 (LAG-3), CD80, CD86, glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR), GITR ligand (GITRL), and programmed death-1 (PD-1). Immune checkpoint molecules were variably expressed on neoplastic and/or microenvironmental cells. Expression of PD-1, OX40L, Galectin-9, and PD-L1 was nearly mutually exclusive on neoplastic cells, suggesting that immune checkpoint pathways differ in patients. Microenvironmental expression of PD-L1, OX40L, and Tim-3 was significantly associated with better overall survival (log-rank test; P =0.0004, 0.0394, and 0.0279, respectively). Univariate and multivariate analyses with clinical prognostic factors identified microenvironmental expression of PD-L1 and OX40L, and age (> 70 years) as significant prognostic factors. This is the first comprehensive analysis of ATLL immune checkpoint molecules. Our results may provide information on new therapeutic strategies in ATLL.

TIM-3: An emerging target in the liver diseases

T cell immunoglobulin domain and mucin domain-containing molecule 3 (TIM-3) is found expression in the surface of terminally differentiated T cells and belongs to the TIM family of type Ⅰ transmembrane proteins. It binds to the ligand Galectin-9 and mediates T cell apoptosis. As the research progresses, TIM-3 is also expressed in Th17, NK, monocyte, which binds to ligand and induce immune peripheral tolerance in both mice and man. Numerous researches have demonstrated that TIM-3 influences liver diseases, including liver-associated chronic viral infection, liver fibrosis, liver cancer et al and suggest new approaches to intervention. Currently, targeted therapy of TIM-3 is a new treatment in the field of immunization. Although many studies have proven that TIM-3 has an inhibitory effect in vivo, the specific mechanism is not clear. Herein, we summarize the important role of TIM-3 in the regulation of liver disease and prospects for future clinical research. TIM-3 will provide new targets for improving clinical liver disease.

Translational Biomarkers and Rationale Strategies to Overcome Resistance to Immune Checkpoint Inhibitors in Solid Tumors

Immune checkpoint inhibitors (ICIs) targeting the programed cell-death protein 1 (PD-1) or its ligand PD-L1 and cytotoxic T-lymphocyte antigen 4 (CTLA-4) pathways have improved the survival for patients with solid tumors. Unfortunately, durable clinical responses are seen in only 10-40% of patients at the cost of potential immune-related adverse events. In the tumor microenvironment (TME), tumor cells can influence the microenvironment by releasing extracellular signals and generating peripheral immune tolerance, while the immune cells can affect the initiation, growth, proliferation, and evolution of cancer cells. Currently, translational biomarkers that predict responses to ICIs include high PD-L1 tumor proportion score, defective DNA mismatch repair, high microsatellite instability, and possibly high tumor mutational burden. Characterization of immune cells in the TME, such as tumor-infiltrating lymphocytes, T-cell gene expression profile, T-cell receptor sequencing, and peripheral blood biomarkers are being explored as promising biomarkers. Recent neoadjuvant studies have integrated the real-time assessment of both molecular and immune biomarkers using the tissue and blood specimens simultaneously and longitudinally. This review summarizes the current knowledge and progress in developing translational biomarkers and rational combinational strategies to improve the efficacy of ICIs tailored to individual cancer patients.

Molecular and immune correlates of TIM-3 (HAVCR2) and galectin 9 (LGALS9) mRNA expression and DNA methylation in melanoma

BACKGROUND

The T cell immunoglobulin and mucin-domain containing-3 receptor TIM-3 (also known as hepatitis A virus cellular receptor 2, encoded by HAVCR2) and its ligand galectin 9 (LGALS9) are promising targets for immune checkpoint inhibition immunotherapies. However, little is known about epigenetic regulation of the encoding genes. This study aimed to investigate the association of TIM-3 and LGALS9 DNA methylation with gene expression, patients' survival, as well as molecular and immune correlates in malignant melanoma.

RESULTS

Methylation of all six TIM-3 CpGs correlated significantly with TIM-3 mRNA levels (P ≤ 0.05). A strong inverse correlation (Spearman's ρ = - 0.49) was found in promoter regions, while a strong positive correlation (ρ = 0.63) was present in the gene body of TIM-3. High TIM-3 mRNA expression (hazard ratio (HR) = 0.88, 95% confidence interval (CI) [0.81-0.97], P = 0.007) was significantly associated with better overall survival. Seven of the eight LGALS9 CpG sites correlated significantly with LGALS9 mRNA levels (P ≤ 0.003). Methylation at five CpG sites showed a strong inverse correlation (Spearman's ρ = - 0.67) and at two sites a weak positive correlation (Spearman's ρ = 0.15). High LGALS9 mRNA expression was significantly associated with increased overall survival (HR = 0.83, 95%CI [0.75-0.93], P = 0.001). In addition, we found significant correlations between TIM-3 and LGALS9 methylation and mRNA expression with immune cell infiltrates and significant differences among distinct immune cell subsets.

CONCLUSIONS

Our study points toward an epigenetic regulation of TIM-3 and LGALS9 via DNA methylation and might provide an avenue for the development of a predictive biomarker for response to immune checkpoint blockade.

Significance of TIM3 expression in cancer: From biology to the clinic

Targeting inhibitory immune checkpoint molecules has dramatically changed treatment paradigms in medical oncology. Understanding the best strategies to unleash a pre-existing immune response or to induce an efficient immune response against tumors has emerged as a research priority. In this work, we focus on a novel target for cancer immunotherapy, the inhibitory receptor T-cell immunoglobulin and mucin domain 3 (TIM3). This narrative review describes TIM3 biology in different (tumor-infiltrating) immune cells, particularly in the immunosuppressive regulatory T cells and dysfunctional/exhausted cytotoxic T lymphocytes, but also in cells that confer innate immunity - natural killer and dendritic cells. We discuss the functional role of TIM3, its expression and its clinical significance in a variety of tumors, and confront the heterogeneous results emerging from different studies, including clinical trials of immunotherapy. Finally, this work summarizes the principal early-phase clinical trials exploring TIM3 blockade and discusses some future perspectives.

Novel immune checkpoint targets: moving beyond PD-1 and CTLA-4

The emergence of immune checkpoint inhibitors (ICIs), mainly including anti-programmed cell death protein 1/programmed cell death ligand 1 (PD-1/PD-L1) and anti-cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) monoclonal antibodies (mAbs), has shaped therapeutic landscape of some type of cancers. Despite some ICIs have manifested compelling clinical effectiveness in certain tumor types, the majority of patients still showed de novo or adaptive resistance. At present, the overall efficiency of immune checkpoint therapy remains unsatisfactory. Exploring additional immune checkpoint molecules is a hot research topic. Recent studies have identified several new immune checkpoint targets, like lymphocyte activation gene-3 (LAG-3), T cell immunoglobulin and mucin-domain containing-3 (TIM-3), T cell immunoglobulin and ITIM domain (TIGIT), V-domain Ig suppressor of T cell activation (VISTA), and so on. The investigations about these molecules have generated promising results in preclinical studies and/or clinical trials. In this review, we discussed the structure and expression of these newly-characterized immune checkpoints molecules, presented the current progress and understanding of them. Moreover, we summarized the clinical data pertinent to these recent immune checkpoint molecules as well as their application prospects.

Immune checkpoints and cancer in the immunogenomics era

Immune checkpoints have been the subject of a wave of new studies. Among these checkpoints are tytotoxic T-lymphocyte-associated antigen 4, checkpoints programmed death-1 and programmed death-ligand 1; their blockades have been approved by the Food and Drug Administration for therapy of melanoma and other types of cancers. Immunogenomics, which combines the latest nucleic acid sequencing strategy with immunotherapy, provides precise information about genomic alterations (e.g. mutations) and enables a paradigm shift of immune checkpoint therapy from tumor types to molecular signatures. Studying these critical checkpoints in relation to genomic mutations and neoantigens has produced groundbreaking results. This article examines these studies and delves into the relationships between immune checkpoint blockade and tumors harboring certain genomic mutations. Moreover, this article reviews recent studies on resistance to immune checkpoint therapy.

Dok-3 deficient mice display different immune clustering and Tim-3 expression

Background

Dok-3 has been shown to play an important role in immune system. Tim-3 also has been recognized as an important immune regulator which involves in many diseases. The relationship of them is still unclear.

Methods

We detected the expression of Tim-3 on spleen immune cells from Dok-3 deficient mice and control mice by flow cytometry.

Results

In this article, we found that Dok-3^−/− mice display almost entirely different immune clustering characteristics compared with wild type 129 mice. The CD4 T cells and CD8 T cells decreased and DC cells, macrophages, MDSCs increased when the Dok-3 gene knocked-out. The Tim-3 expression on CD4 T cells, CD8 T cells, NK cells, DC cells increased when the Dok-3 gene knocked-out. The macrophages and MDSCs just display the opposite results.

Conclusions

Although Dok-3^−/− mice display different immune clustering and Tim-3 expression, the mechanism still needs further study.

Electronic supplementary material

The online version of this article (10.1186/s40001-019-0384-7) contains supplementary material, which is available to authorized users.

Tailoring Nanomaterials for Targeting Tumor-Associated Macrophages

Advances in the field of nanotechnology together with an increase understanding of tumor immunology have paved the way for the development of more personalized cancer immuno-nanomedicines. Nanovehicles, due to their specific physicochemical properties, are emerging as key translational moieties in tackling tumor-promoting, M2-like tumor-associated macrophages (TAMs). Cancer immuno-nanomedicines target TAMs primarily by blocking M2-like TAM survival or affecting their signaling cascades, restricting macrophage recruitment to tumors and re-educating tumor-promoting M2-like TAMs to the tumoricidal, M1-like phenotype. Here, the TAM effector mechanisms and strategies for targeting TAMs are summarized, followed by a focus on the mechanistic considerations in the development of novel immuno-nanomedicines. Furthermore, imaging TAMs with nanoparticles so as to forecast a patient's clinical outcome, describing treatment options, and observing therapy responses is also discussed. At present, strategies that target TAMs are being investigated not only at the basic research level but also in early clinical trials. The significance of TAM-targeting biomaterials is highlighted, with the goal of facilitating future clinical translation.

Interaction of Breast Cancer and Insulin Resistance on PD1 and TIM3 Expression in Peripheral Blood CD8 T Cells

Epidemiological evidence points to a link between insulin resistance (IR) and breast cancer (BrCA). Insulin plays a role in CD8+ T cells (CD8T) differentiation and function and affects adipocytokines levels. CD8T activity in BrCA is associated with favorable outcome; while PD1 and TIM3 are markers of CD8T exhaustion and play critical roles in the negative regulation of T cell responses. Patients with (BrCA) have high expression levels of PD1 on circulating. Therefore, we hypothesized that BrCA and IR could affect PD1 and/or TIM3 expression on circulating CD8T. We determine PD1 and TIM3 expression on CD8T and analyze the relationship of CD8T phenotype with serum insulin and plasma adipocytokines levels in the different groups. We enrolled four groups of treatment-naive patients: women without neoplasms (Neo-)/without IR (IR-), Neo-/with IR (IR+), BrCa/IR- and BrCa/IR+. We found interactions between BrCA and IR with respect to TIM3 on naïve and central memory (CM) CD8T subsets. Furthermore, BrCA had a greater PD1 + TIM3- CD8T frequency in CD8T subsets than Neo-. IR+ presented a significantly lower PD1 + TIM3- frequency in CD8T subsets compare to Non-IR. In addition, we found a negative correlation between insulin levels, HOMA and frequency of PD1 + TIM3- in CD8T and a positive correlation between adiponectin levels and the frequency PD1 + TIM3- in CD8T. The increased expression of PD1 on different subsets of CD8T from BrCa patients is consistent with immunological tolerance, whereas IR has a contrary effect. IR could have a deleterious role in the activation of CD8T that can be relevant to new BrCa immunotherapy.

Recent Advances in Polymeric Nanomedicines for Cancer Immunotherapy

Immunotherapy has emerged as a promising approach to treat cancer, since it facilitates eradication of cancer by enhancing innate and/or adaptive immunity without using cytotoxic drugs. Of the immunotherapeutic approaches, significant clinical potentials are shown in cancer vaccination, immune checkpoint therapy, and adoptive cell transfer. Nevertheless, conventional immunotherapies often involve immune-related adverse effects, such as liver dysfunction, hypophysitis, type I diabetes, and neuropathy. In an attempt to address these issues, polymeric nanomedicines are extensively investigated in recent years. In this review, recent advances in polymeric nanomedicines for cancer immunotherapy are highlighted and thoroughly discussed in terms of 1) antigen presentation, 2) activation of antigen-presenting cells and T cells, and 3) promotion of effector cells. Also, the future perspectives to develop ideal nanomedicines for cancer immunotherapy are provided.

Using the Spleen as an In Vivo Systemic Immune Barometer Alongside Osteosarcoma Disease Progression and Immunotherapy with α-PD-L1

Indications for immunotherapies are still unclear, and there is a great need for real-time patient immune status monitoring. In this study, we confirmed that the local and systemic immune profiles of an orthotopic osteosarcoma model with or without luciferase transfection were statistically equivalent. Next, we used flow cytometry to describe systemic immune cell populations influenced by osteosarcoma disease progression. When compared to vehicle-inoculated sham mice, it was found that tumor-bearing mice had significant immunophenotype disturbances at approximately 11 weeks after inoculation (at which time 90% of primary tumor-bearing mice have fulminant pulmonary metastases). Percent populations of natural killer cells and T regulatory cells were increased in the spleens of tumor-bearing mice (p < 0.0083) compared to shams. Additionally, T lymphocytes from spleens of tumor-bearing mice showed increased Tim-3/PD-1 exhaustion status (p < 0.0083). There were also increases in the percent populations of myeloid cells and overall M1/M2 macrophage marker expression on tumor-bearing mice spleens versus controls (p < 0.00714). Finally, treatment with 20 μg α-PD-L1 decreased T-cell exhaustion back to sham status, with a corresponding increase in CTLA-4 expression on cytotoxic T cells in the majority of mice tested. Checkpoint inhibition also increased splenic monocyte maturation and returned macrophage M1/M2 marker expression back to sham status. These data suggest that cancer induces systemic immune dysregulation and that these changes may be elucidated and utilized for treatment purposes by sampling the systemic immune environment via the spleen. In addition, treatment with the checkpoint inhibitor α-PD-L1 may neutralize but not overcome the systemic immunological changes induced by a progressing malignancy.

Immune checkpoint blockade opens a new way to cancer immunotherapy

Among the main promising systems to triggering therapeutic antitumor immunity is the blockade of immune checkpoints. Immune checkpoint pathways regulate the control and eradication of infections, malignancies, and resistance against a host of autoantigens. Initiation point of the immune response is T cells, which have a critical role in this pathway. As several immune checkpoints are initiated by ligand-receptor interactions, they can be freely blocked by antibodies or modulated by recombinant forms of ligands or receptors. Antibodies against cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) were the first immunotherapeutics that achieved the US Food and Drug Administration approval. Preliminary clinical results with the blockers of additional immune checkpoint proteins, such as programmed cell death protein 1 (PD-1) indicate extensive and different chances to boost antitumor immunity with the objective of conferring permanent clinical effects. This study provides an overview of the immune checkpoint pathways, including CTLA-4, PD-1, lymphocyte activation gene 3, T-cell immunoglobulin and mucin domain 3, B7-H3, and diacylglycerol kinase α and implications of their inhibition in the cancer therapy.

Tim-3 blockade promotes iNKT cell function to inhibit HBV replication

Increased expression of T cell immunoglobulin and mucin domain-3 (Tim-3) on invariant natural killer T (iNKT) cells is reported in chronic hepatitis B virus (HBV) infection. However, whether Tim-3 regulates iNKT cells in chronic HBV condition remains unclear. In this study, our results showed that the expression of Tim-3 was up-regulated on hepatic iNKT cells from HBV-transgenic (Tg) mice or iNKT cells stimulated with α-galactosylceramide (α-Galcer). Compared with Tim-3- iNKT cells, Tim-3+ iNKT cells expressed more IFN-γ, IL-4 and CD107a, indicating a strong relationship between Tim-3 and iNKT cell activation. Constantly, treatment of Tim-3 blocking antibodies significantly enhanced the production of IFN-γ, TNF-α, IL-4 and CD107a in iNKT cells both in vivo and in vitro. This Tim-3- mediated suppression of iNKT cells was further confirmed in Tim-3 knockout (KO) mice. Moreover, Tim-3 blockade promoted α-Galcer-triggered inhibition of HBV replication, displaying as the decreased HBV DNA and HBsAg level in serum, and down-regulated pgRNA expression in liver tissues. Collectively, our data, for the first time, demonstrated the potential role of Tim-3 blockade in promoting iNKT cell-mediated HBV inhibition. Therefore, combination of α-Galcer with Tim-3 blockade might be a promising approach in chronic hepatitis B therapy.

TIM-3 is a potential prognostic marker for patients with solid tumors: A systematic review and meta-analysis

Accumulated studies have demonstrated the important role of T cell immunoglobulin- and mucin-domain-containing molecule-3 (TIM-3) in various solid tumors and indicated its correlation with patients’ survival. To further verify the prognostic significance of TIM-3 in cancer patients and its correlation with tumor, we performed this meta-analysis including seven studies searched from PubMed, Web of Science, and Embase till July 2016. A total of 869 patients were used to analyze the association between TIM-3 expression and patients’ overall survival (OS). The pooled results showed that higher expression of TIM-3 was significantly correlated to shorter OS (7 studies, HR=1.89; 95% CI: 1.38-2.57; P< 0.001). In addition, higher TIM-3 expression was associated with advanced tumor stage (3 studies, III/IV vs. I/II, RR=2.02; 95% CI: 1.45–2.81; P< 0.001). In conclusion, our study highlights the role of TIM-3 as a potential prognostic marker and a promising therapeutic target in solid tumors.

Elevated Galectin-9 Suppresses Th1 Effector Function and Induces Apoptosis of Activated CD4+ T Cells in Osteoarthritis

T cell immunoglobulin and mucin domain 3 (Tim-3) is a critical regulatory molecule found on activated Th1 cells, exhausted CD8⁺ T cells, and resting monocytes/macrophages. Galectin-9 (Gal-9) is an identified ligand for Tim-3. Interaction between Tim-3 and Gal-9 is thought to inhibit Th1 responses. The regulation and function of Tim-3 and Gal-9 in osteoarthritis (OA) have not been intensively investigated. We found that in peripheral blood, CD4⁺ T cells, but not CD8⁺ T cells or CD14⁺ monocytes, from OA patients presented significantly elevated Tim-3 and Gal-9 expression compared to those from healthy controls (HC). The CD4⁺ T cells from OA did not present altered Th1, Th2, and Th17 composition in the peripheral blood, but secreted less Th1 cytokine interleukin 2 (IL-2) and interferon gamma (IFN-γ) after activation. Further investigation demonstrated that Gal-9 induced high levels of apoptosis in activated CD4⁺ T cells from OA patients. Inhibition of Gal-9 resulted in significantly higher IL-2 and IFN-γ expression that was directly correlated with the number of non-apoptotic cells. In the synovial fluid, both secreted Gal-9 and surface Gal-9 levels were significantly higher in less-severe grade 2 OA patients than in more-severe grade 4 OA patients. Surface Tim-3 was also higher in synovial fluid CD8⁺ T cells and CD14⁺ monocytes from grade 2 OA patients and lower in grade 4 OA patients. Together, these results suggested that Tim-3 and Gal-9 could downregulate T cell inflammation in OA, and could be utilized as a novel therapeutic strategy.

Tumor cell-intrinsic Tim-3 promotes liver cancer via NF-κB/IL-6/STAT3 axis

T-cell immunoglobulin and mucin-domain containing-3 (Tim-3), mediating immune exhaustion in tumor microenvironment, has become a promising target for tumor therapy. However, the exact mechanisms for tumor cell-intrinsic Tim-3 in tumor development and its potential contribution in Tim-3-targeted therapy strategy have not been elucidated yet. In this study, we showed that human liver cancer tissues contained high ratio of Tim-3-expressing hepatocytes, and cytokines rich in tumor microenvironment and HBV involved in Tim-3 upregulation in malignant hepatocytes. We demonstrated that hepatocyte-specific Tim-3 overexpression enhances tumor cell growth, whereas Tim-3 inhibition on malignant hepatocytes by anti-Tim-3 antibodies or RNAi suppresses tumor growth both in vitro and in Tim-3 knockout mice. Mechanistically, the hepatocyte-Tim-3 receptor activates NF-κB phosphorylation, which in turn stimulates IL-6 secretion and STAT3 phosphorylation. Our results identify tumor cell-intrinsic functions of Tim-3 in tumorigenesis and suggest that blocking Tim-3 in tumor cells might contribute to the clinical efficacy of anti-Tim-3 antibody treatment in the future tumor therapy.

FOXOs in cancer immunity: Knowns and unknowns

In the tumor microenvironment (TME), cancer cells, stromal cells, and immune cells, along with their extracellular factors, have profound effects on either promoting or repressing anti-cancer immunity. Accumulating evidence has shown the paradoxical intrinsic role of the Forkhead box O (FOXO) family of transcription factors in cancer, which can act as a tumor repressor while also maintaining cancer stem cells. FOXOs also regulate cancer immunity. FOXOs promote antitumor activity through negatively regulating the expression of immunosuppressive proteins, such as programmed death 1 ligand 1 (PD-L1), and vascular endothelial growth factor (VEGF) in tumor cells or stromal cells, which can shape an immunotolerant state in the TME. FOXOs also intrinsically control the anti-tumor immune response as well as the homeostasis and development of immune cells, including T cells, B cells, natural killer (NK) cells, macrophages, and dendritic cells. As a cancer repressor, reviving the activity of Foxo1 forces tumor-infiltrating activated regulatory T (T_reg) cells to egress from tumor tissues. As a promoter of cancer development, Foxo3 and Foxo1 negatively regulate cytotoxicity of both CD8⁺ T cells and NK cells against tumor cells. In this review, we focus on the complex role of FOXOs in regulating cancer immunity due to the various roles that they play in cancer cells, stromal cells, and immune cells. We also speculate on some possible additional roles of FOXOs in cancer immunity based on findings regarding FOXOs in non-cancer settings, such as infectious disease.

On the significance of Tim-3 expression in pancreatic cancer

OBJECTIVE

We aim to explore the connection between Tim-3 expression in both cancerous pancreatic and pericarcinous tissues and the clinicopathological features of pancreatic cancer. We will also preliminarily assess the role and significance of Tim-3 in the diagnosis, treatment, and prognosis of pancreatic cancer.

METHODS

Cancerous pancreatic and pericarcinous tissues from 50 patients with pancreatic cancer and six healthy pancreatic tissues were collected from the pathological specimens of traumatic patients to distinguish Tim-3 expression using immunohistochemistry. Tim-3 expression was observed to be correlated with cell invasion, metastasis, and recurrence of pancreatic cancer.

RESULTS

1. For the immunohistochemical method, Tim-3 expression in pancreatic cancer tissues was observed to be elevated and statistically significant (P < .01) compared to pericarcinous and normal pancreatic tissues. No statistically significant difference (P > .05) was observed between Tim-3 expression in pericarcinous and normal pancreatic tissues. 2. While Tim-3 expression was observed to be closely related to the history of smoking, fasting blood glucose, tumor size, TNM stage, it was not observed to be related to gender, age, tumor location, pathological type, and degree of tumor differentiation.

CONCLUSION

1. Tim-3 expression in pancreatic cancer tissues was high. 2. The high Tim-3 expression in pancreatic cancer tissues may be closely related to cell invasion, metastasis, and the recurrence of pancreatic cancer.

Phosphatidylserine-Induced Conformational Modulation of Immune Cell Exhaustion-Associated Receptor TIM3

In the face of chronic cancers and protracted viral infections, human immune cells are known to adopt an exhausted state in which their effector functions are lost. In recent years, a number of inhibitory receptors have been connected to the immune cell exhaustion phenotype; furthermore, ligands capable of activating these receptors have been discovered. The molecular mechanisms by which these ligands affect the exhausted states of immune cells, however, are largely unknown. Here, we present the results of molecular dynamics simulations of one potential exhaustion-associated system: the complex of human inhibitory receptor TIM3 (hTIM3) and its ligand phosphatidylserine (PSF). We find that PSF fundamentally alters the electrostatic environment within hTIM3's Ca²⁺ binding site, facilitating the formation of a salt bridge and freeing a tyrosine-containing strand. This liberated tyrosine then collapses into a nearby hydrophobic pocket, anchoring a modified conformational ensemble typified by a β-strand rearrangement. The "electrostatic switching/hydrophobic anchoring" mechanism of conformational modulation reported here suggests a new type of process by which TIM3 activation might be achieved. This work also highlights strategies by which PSF-mediated conformational change could be controlled, either through administration of small molecules, execution of mutations, or modification of receptor phosphorylation states.

Stimulation of Camel Polyclonal Antibody against Human T cell Immunoglobulin and Mucin 3

Background: T cell Immunoglobulin, Mucin (TIM)-3, is a type I transmembrane glycoprotein belonging to TIM family. This receptor expresses on T helper type 1 (Th1) cells that binds to galectin-9 (Gal9); inducing an inhibitory signal. As a result, apoptosis of Th1 cells occurs and cytotoxicity of CD8 T cells becomes evident in vitro. Therefore, this immunomodulatory molecule may be used as a novel target for clinical purposes. The production of camel polyclonal antibodies against TIM-3-expressing cell line was the purpose of this study. Objectives: In this study, we aimed to use HEK 293 cells expressing human TIM-3 to obtain camel polyclonal antibody against TIM-3 by immunization. Materials and Methods: A pre-synthesized human TIM-3cDNA was inserted into pcDNA3.1 plasmid and the new construct was transfected in HEK cell. TIM-3 expression was confirmed by qRT-PCR and flow cytometry. A camel (6 months old) was immunized with the lysate prepared from rTIM-3 expressing HEK cells 4 times. The anti-TIM-3 antibody level was evaluated using ELISA method. Results: TIM-3 was successfully cloned in HEK cells with 88% success rate. High level of anti-TIM-3 antibody was detected in the serum of the camel immunized with the recombinant cell lysate, after final injection. Conclusions: Our rhTIM-3 cell display system can be useful for future diagnostic or therapeutic approaches.

Trial watch: Immune checkpoint blockers for cancer therapy

Immune checkpoint blockers (ICBs) are literally revolutionizing the clinical management of an ever more diversified panel of oncological indications. Although considerable attention persists around the inhibition of cytotoxic T lymphocyte-associated protein 4 (CTLA4) and programmed cell death 1 (PDCD1, best known as PD-1) signaling, several other co-inhibitory T-cell receptors are being evaluated as potential targets for the development of novel ICBs. Moreover, substantial efforts are being devoted to the identification of biomarkers that reliably predict the likelihood of each patient to obtain clinical benefits from ICBs in the absence of severe toxicity. Tailoring the delivery of specific ICBs or combinations thereof to selected patient populations in the context of precision medicine programs constitutes indeed a major objective of the future of ICB-based immunotherapy. Here, we discuss recent preclinical and clinical advances on the development of ICBs for oncological indications.

T-cell immunoglobulin mucin-3 expression in invasive ductal breast carcinoma: Clinicopathological correlations and association with tumor infiltration by cytotoxic lymphocytes

As a negative regulatory molecule, T-cell immunoglobulin and mucin domain-3 (Tim-3) is closely associated with tumor immunological tolerance. The aim of this study was to investigate Tim-3 expression in invasive ductal breast cancer (IDC), its effect on clinicopathological parameters and its association with cytotoxic lymphocyte infiltration. Tim-3 protein expression was measured in 150 paraffin-embedded IDC specimens and 100 paired normal breast tissue specimens by immunohistochemistry. It was demonstrated that the infiltration of the tumor by CD8⁺ T cells was significantly higher compared with that of normal tissue, and the Tim-3 expression on CD8⁺ T cells was higher in IDC tissue compared with that in normal tissue; the differences were statistically significant (both P-values=0.000). The median expression level of Tim-3 on tumor cells was significantly associated with clinicopathological parameters such as age, axillary lymph node metastasis and TNM stage (P=0.015, 0.001 and 0.027, respectively). The expression of Tim-3 on CD8⁺ T cells was correlated with lymph node metastasis, World Health Organization (WHO) grade and molecular classification (P=0.000, 0.004 and 0.000, respectively). Additionally, the number of tumor-infiltrating CD8⁺ T cells was associated with primary tumor size, lymph node metastasis, WHO grade, Ki-67 and molecular classification (P=0.017, 0.002, 0.007, 0.003 and 0.000, respectively). Thus, Tim-3 may promote the development and progression of breast cancer and affect the tumor microenvironment; thus, it may be used as an independent prognostic factor for IDC patients.

Analysis of Tim-3 as a therapeutic target in prostate cancer

Tim-3 (T-cell immunoglobulin domain and mucin domain-containing molecule 3) is a newly discovered immunomodulatory protein, which plays an important role in immunity regulation. Recent evidence suggests that Tim-3 is differentially regulated in a variety of tumors and has potential as a therapeutic target. The aim of this study was to investigate the effect of Tim-3 on the development of prostate cancer. Tim-3 expressing on peripheral CD4+ T and CD8+ T cells was analyzed by flow cytometry. The relationships between Tim-3 expression and clinicopathological features were analyzed. Immunohistochemical expression of Tim-3 was examined in our large numbers of paraffin-fixed prostate tissues. Flow cytometry revealed that expression of Tim-3 was significantly increased on both CD4+ and CD8+ T cells in prostate cancer patients than that in benign prostate hyperplasia patients. Also, the level of Tim-3 on CD4+ T cells was positively correlated with CD8+ T cells in patients. Further analyses revealed that the levels of Tim-3 on CD4+ T cells and CD8+ T cells exhibited different expression patterns in terms of localization depending on pathological category of prostate cancer and metastasis. Immunohistochemical analysis revealed that positive staining of Tim-3 in prostate cancer but little or no staining of Tim-3 was observed in benign prostate hyperplasia epithelium. Tim-3 may affect the development and progression of prostate cancer, which may provide knowledge for using Tim-3 as a novel therapy for effective prostate cancer management.

Effects of Tim-3 silencing on the viability of fibroblast-like synoviocytes and lipopolysaccharide-induced inflammatory reactions

The objective of the present study was to investigate the effects of Tim-3 silencing on cell viability and lipopolysaccharide (LPS)-induced inflammatory reactions in fibroblast-like synoviocytes (FLS). T-cell immunoglobulin mucin domain molecule (Tim)-3 expression in FLS obtained from patients with rheumatoid arthritis (RA) and normal controls were detected by western blot analysis and reverse transcription-polymerase chain reaction (RT-PCR). Small interfering (si)RNA was transfected using Lipofectamine^® 2000 to decrease Tim-3 expression. Following transfection, FLS were stimulated by LPS. An MTT assay, RT-PCR and western blot analysis were performed to measure cell viability, Toll-like receptor 4 (TLR4) signaling pathway-related protein expression and inflammatory cytokine release, respectively. The results of the present study indicated that Tim-3 expression was increased in FLS from patients with RA compared with FLS from healthy controls. Transfection of Tim-3 siRNA significantly decreased Tim-3 expression in FLS from patients with RA. Notably, Tim-3 silencing decreased FLS cell viability. Following stimulation with LPS, cell viability and the expression of TLR4, myeloid differentiation protein gene 88 (MyD88) and nuclear factor-κB (NF-κB) p65 were enhanced in FLS. By contrast, Tim-3 silencing attenuated LPS-induced cell proliferation and the expression of TLR4, MyD88 and NF-κB p65. In addition, LPS significantly increased levels of cytokines in the supernatant, including tumor necrosis factor-α, interferon-γ and interleukin-6 (P<0.01). By contrast, Tim-3 silencing significantly decreased LPS-induced cytokine release (P<0.01). However, Tim-3 silencing did not affect TLR4, MyD88 and NF-κB p65 expression and the release of cytokines in cells that did not undergo treatment with LPS. Therefore, the results of the present study indicate that Tim-3 silencing decreases the viability of FLS in RA and attenuates the LPS-induced inflammatory reaction.

Immune checkpoint inhibitor combinations in solid tumors: opportunities and challenges

The emergence of immune 'checkpoint inhibitors' such as cytotoxic T-lymphocyte antigen 4 (CTLA-4) and programmed death receptor 1 (PD-1) has revolutionized treatment of solid tumors including melanoma, lung cancer, among many others. The goal of checkpoint inhibitor combination therapy is to improve clinical response and minimize toxicities. Rational design of checkpoint combinations considers immune-mediated mechanisms of antitumor activity: immunogenic cell death, antigen release and presentation, activation of T-cell responses, lymphocytic infiltration into tumors and depletion of immunosuppression. Potential synergistic combinations include checkpoint blockade with conventional (radiation, chemotherapy and targeted therapies) and newer immunotherapies (cancer vaccines, oncolytic viruses, among others). Reliable biomarkers are necessary to define patients who will achieve best clinical benefit with minimal toxicity in combination therapy.

Tumor immunotherapy: drug-induced neoantigens (xenogenization) and immune checkpoint inhibitors

More than 40 years ago, we discovered that novel transplantation antigens can be induced in vivo or in vitro by treating murine leukemia with dacarbazine. Years later, this phenomenon that we called "Chemical Xenogenization" (CX) and more recently, "Drug-Induced Xenogenization" (DIX), was reproduced by Thierry Boon with a mutagenic/carcinogenic compound (i.e. N-methyl-N'-nitro-N-nitrosoguanidine). In both cases, the molecular bases of DIX rely on mutagenesis induced by methyl adducts to oxygen-6 of DNA guanine. In the present review we illustrate the main DIX-related immune-pharmacodynamic properties of triazene compounds of clinical use (i.e. dacarbazine and temozolomide).In recent years, tumor immunotherapy has come back to the stage with the discovery of immune checkpoint inhibitors (ICpI) that show an extraordinary immune-enhancing activity. Here we illustrate the salient biochemical features of some of the most interesting ICpI and the up-to-day status of their clinical use. Moreover, we illustrate the literature showing the direct relationship between somatic mutation burden and susceptibility of cancer cells to host's immune responses.When DIX was discovered, we were not able to satisfactorily exploit the possible presence of triazene-induced neoantigens in malignant cells since no device was available to adequately enhance host's immune responses in clinical settings. Today, ICpI show unprecedented efficacy in terms of survival times, especially when elevated mutation load is associated with cancer cells. Therefore, in the future, mutation-dependent neoantigens obtained by appropriate pharmacological intervention appear to disclose a novel approach for enhancing the therapeutic efficacy of ICpI in cancer patients.

Preoperative Tim‑3 expression on peripheral NK cells is correlated with pathologic TNM staging in colorectal cancer

Previous research has indicated that T cell immunoglobulin and mucin domain 3 (Tim-3) serves an important regulatory role in lymphocytes and in several cancers. However, the association between Tim‑3 expression on various lymphocyte subsets and human colorectal cancer (CRC) has not been elucidated. The present study aimed to characterize Tim‑3 expression on peripheral lymphocytes, including cluster of differentiation CD3+CD56‑ T cells, CD3‑CD56+ natural killer (NK) cells and CD3+CD56+ natural killer T (NKT) cells, in patients with CRC. The frequency of T cells, NK cells and NKT cells expressing Tim‑3 was assessed by multicolor flow cytometry of peripheral blood collected from 36 preoperative CRC patients and 38 healthy donors. The expression of Tim‑3 on lymphocyte subsets from 53 postoperative blood samples of CRC patients was also analyzed. There were fewer circulating NK cells in patients with CRC compared with healthy controls (P=0.0027); NK cell expression of Tim‑3 was also significantly decreased (P=0.0239). The frequency of circulating NK cells and Tim‑3+ NK cells was negatively correlated with clinical cancer stage, compared with healthy controls, but not with other clinicopathological parameters or serum concentrations of CRC biomarkers. Furthermore, the expression of Tim‑3 in NK cells was higher in CRC patients without metastasis. Notably, NK cell Tim‑3 expression in CRC patients was significantly restored following surgical resection of the primary tumor. In conclusion, the present study indicates the presence of an altered frequency and expression of Tim‑3 in peripheral NK cells in CRC patients. Preoperative Tim‑3 expression on peripheral NK cells is correlated with differential staging in colorectal cancer, and may be useful as a serum biomarker.

Elevated frequencies of CD8 T cells expressing PD-1, CTLA-4 and Tim-3 within tumour from perineural squamous cell carcinoma patients

Perineural spread of tumour cells along cranial nerves is a severe complication of primary cutaneous squamous cell carcinomas of the head and neck region. While surgical excision of the tumour is the treatment of choice, removal of all the tumour is often complicated by the neural location and recurrence is frequent. Non-invasive immune treatments such as checkpoint inhibitor blockade may be useful in this set of tumours although little is understood about the immune response to perineural spread of squamous cell carcinomas. Immunohistochemistry studies suggest that perineural tumour contains a lymphocyte infiltrate but it is difficult to quantitate the different proportions of immune cell subsets and expression of checkpoint molecules such as PD-1, Tim-3 and CTLA-4. Using flow cytometry of excised perineural tumour tissue, we show that a T cell infiltrate is prominent in addition to less frequent B cell, NK cell and NKT cell infiltrates. CD8 T cells are more frequent than other T cells in the tumour tissue. Amongst CD8 T cells, the frequency of Tim-3, CTLA-4 and PD-1 expressing cells was significantly greater in the tumour relative to the blood, a pattern that was repeated for Tim-3, CTLA-4 and PD-1 amongst non-CD8 T cells. Using immunohistochemistry, PD-1 and PD-L1-expression could be detected in close proximity amongst perineural tumour tissue. The data suggest that perineural SCC contains a mixture of immune cells with a predominant T cell infiltrate containing CD8 T cells. Elevated frequencies of tumour-associated Tim-3⁺, CTLA-4⁺ and PD-1⁺ CD8 T cells suggests that a subset of patients may benefit from local antibody blockade of these checkpoint inhibitors.

Role of TIM-3 in ovarian cancer

Evidences have suggested that immunotherapy for ovarian cancer is effective. Immune checkpoints have emerged in the field of cancer immunotherapy. Multiple studies have shown negative regulation of TIM-3 expression on CD4⁺ and CD8⁺ T cells and other immunocytes. Overexpression of TIM-3 in innate immune cells has been found in certain types of tumor. The blockade of TIM-3 leads to sustained anti-tumor reactions. TIM-3 plays an inhibitive role for immunity in ovarian cancer. TIM-3 is involved in the development of various subtypes of ovarian cancer and thus has the potential to be a therapeutic target for treatment of ovarian cancer.

Tim-3 Up-regulation in Patients with Gastric Cancer and Peptic Ulcer Disease

Background:

T-cell immunoglobulin and mucin domain protein-3 (Tim-3), an inhibitory immunoregulatory receptor, has been recently implicated in tumor biology and tumor-associated immune suppression. In the present study, expression of Tim-3 was evaluated in gastric cancer (GC) and peptic ulcer disease (PUD) at both mRNA and protein levels.

Methods:

A total of 133 gastric tissue biopsies, comprising 43 from GC cases, 48 from PUD and 42 from non-ulcer dyspepsia (NUD) serving as controls were collected. Additionally, non-neoplastic adjacent tissue biopsies were also obtained from 6 patients with GC. Infection with Helicobacter pylori was determined by the rapid urease test for all participants and H&E staining was conducted for GC and PUD patients. Tim-3 relative mRNA expression was determined by SYBR Green based Real-Time PCR using β-actin as a reference gene. Tim-3 protein expression was also studied by immunohistochemistry in 7 GC, 7 PUD and 10 NUD tissue samples.

Results:

Tim-3 was expressed at higher levels in GC (p=0.030) and PUD (p=0.022) cases compared to he NUD group. Among paired samples obtained from gastric cancer patients, tumor tissues showed elevated Tim-3 expression (p=0.019) in comparison with adjacent non-neoplastic biopsies. Tim-3 mRNA findings were supported by detection of more Tim-3 protein in cancerous (p=0.002) and ulcerative (p=0.01) tissues than in controls. Tim-3 was similarly expressed in H. pylori positive and negative cases.

Conclusion:

Higher Tim-3 expression in patients with gastric cancer and peptic ulcer implies that it might be involved in immune regulation and establishment of these gastrointestinal diseases. Targeted immunotherapy by blocking of inhibitory receptors like Tim-3 could be a promising approach for gastric cancer treatment.

Radiotherapy in the age of cancer immunology: Current concepts and future developments

Major advances in the knowledge of cancer biology and its interactions with tumor immune environment led to the emergence, in the last five years of new immunotherapy-based treatment strategies in cancer patients. At the same time, improvement in radiation technique and progress in radiobiology allowed in the last decade to expand the applications of radiotherapy in a growing number of settings. At present, there are strong theoretical basis to propose immune-enhanced radiation therapy that may represent in the future a new paradigm of treatment, combining the intrinsic power of radiotherapy to elicit a specific, systemic, tumor-directed immune response with modern highly conformal and precise dose delivery, in order to maximize response at the major site of disease and obtain durable disease control. The aim of this review is to describe the principal mechanisms of immune modulation of response to radiation and investigational strategies to harness the potential of radiation-inducible immune response: radiation therapy is expected to be not just a local treatment but the cornerstone of a multimodal strategy that might achieve long-lasting tumor remission at the primary site and systemic efficacy metastatic lesions.

Blockade of high mobility group box 1 augments antitumor T-cell response induced by peptide vaccination as a co-adjuvant

High mobility group box 1 (HMGB1) is a member of the family of damage-associated molecular patterns, which cause inflammation and trigger innate immunity through Toll-like receptors 2/4 and the receptor for advanced glycation end products. We examined the effect of glycyrrhizin, a selective inhibitor of HMGB1, on the induction of CTLs in mice. B6 mice, either OT-1 spleen cell-transferred or untransferred, were immunized with an s.c. injection of OVA_257-264 peptide with topical imiquimod, and glycyrrhizin was mixed with the antigen peptide. Proliferation of OT-1 cells after immunization was enhanced by glycyrrhizin. The effect of glycyrrhizin was confirmed in other adjuvant systems, such as CpG oligonucleotide and monophosphoryl lipid A, but glycyrrhizin was not effective in Freund's incomplete adjuvant system. The augmenting effects of glycyrrhizin were also observed in other synthetic HMGB1 inhibitors, gabexate mesilate, nafamostat, and sivelestat. Thus, the effects are common to the HMGB1 inhibitors. Induction of CTLs detected by γ-interferon enzyme-linked immunospot assay was similarly augmented by glycyrrhizin. In a therapeutic vaccine model, glycyrrhizin inhibited the growth of s.c. transplanted EG.7 tumors. Expression of inflammatory cytokines in the skin inoculation site was downregulated by glycyrrhizin. These results suggest that HMGB1 inhibitors might be useful as a co-adjuvant for peptide vaccination with an innate immunity receptor-related adjuvant.

T cell immunoglobulin and mucin domain-containing molecule 3 on CD14+ monocytes serves as a novel biological marker for diabetes duration in type 2 diabetes mellitus

Aims/Introduction

Type 2 diabetes is a worldwide disease that is associated with increased rates of obesity and reduced physical activity. Obesity‐associated insulin resistance in type 2 diabetes is a disorder in the balance between pro‐inflammatory and anti‐inflammatory signals. T cell immunoglobulin and mucin domain‐containing molecule 3 (Tim‐3) has been reported as an important regulatory inflammation molecule, and plays a pivotal role in several inflammation‐related diseases.

Materials and Methods

Peripheral blood mononuclear cells were obtained from type 2 diabetes patients (n = 31) and healthy donors (n = 18), and Tim‐3 expression on peripheral blood mononuclear cells was evaluated by flow cytometry.

Results

We showed the downregulated expression of Tim‐3 on CD14⁺ monocytes from type 2 diabetes patients. In addition, the upregulated expression of Tim‐3 on peripheral CD4⁺ T cells and CD8⁺ T cells was observed in the present study. The correlation analysis between Tim‐3 expression on CD14⁺ monocytes and diabetes duration showed the longer diabetes duration time, the lower Tim‐3 expression on CD14 monocytes.

Conclusions

The present results suggest that Tim‐3 might participate in the progression of type 2 diabetes by its negative regulation on these immune cells, and Tim‐3 on CD14⁺ monocytes serves as a novel biological marker for diabetes duration in type 2 diabetes patients.

Impaired functional responses in follicular lymphoma CD8+TIM-3+ T lymphocytes following TCR engagement

Upregulation of T cell immunoglobulin-3 (TIM-3) has been associated with negative regulation of the immune response in chronic infection and cancer, including lymphoma. Here, we investigated the possible correlation between TIM-3 expression by ex vivo cytotoxic T cells (CTL) from follicular lymphoma (FL) biopsies and their functional unresponsiveness that could limit the favorable impact of CTL on disease progression. We report a high percentage of CD8⁺TIM-3⁺T cells in lymph nodes of FL patients. When compared to their CD8⁺TIM-3^- counterparts, CD8⁺TIM-3⁺ T cells exhibited defective cytokine production following TCR engagement. Furthermore, CD8⁺TIM-3⁺ T cells display ex vivo markers of lytic granule release and remain unresponsive to further TCR-induced activation of the lytic machinery. Although confocal microscopy showed that TIM-3 expression on CD8⁺ T cells correlated with minor alterations of immunological synapse, a selective reduction of ERK signaling in CD8⁺TIM-3⁺T cells was observed by phospho-flow analysis. Finally, short relapse-free survival despite rituximab(R)-chemotherapy was observed in patients with high content of TIM-3⁺ cells and a poor infiltrate of granzyme B⁺ T cells in FL lymph nodes. Together, our data indicate that, besides selective TCR early signaling defects, TIM-3 expression correlates with unresponsiveness of ex vivo CD8⁺ T cells in FL. They show that scores based on the combination of exhaustion and cytolytic markers in FL microenvironment might be instrumental to identify patients at early risk of relapses following R-chemotherapy.

Differential expression and biochemical activity of the immune receptor Tim-3 in healthy and malignant human myeloid cells

The T cell immunoglobulin and mucin domain 3 (Tim-3) is a plasma membrane-associated receptor which is involved in a variety of biological responses in human immune cells. It is highly expressed in most acute myeloid leukaemia (AML) cells and therefore may serve as a possible target for AML therapy. However, its biochemical activities in primary human AML cells remain unclear. We therefore analysed the total expression and surface presence of the Tim-3 receptor in primary human AML blasts and healthy primary human leukocytes isolated from human blood. We found that Tim-3 expression was significantly higher in primary AML cells compared to primary healthy leukocytes. Tim-3 receptor molecules were distributed largely on the surface of primary AML cells, whereas in healthy leukocytes Tim-3 protein was mainly expressed intracellularly. In primary human AML blasts, both Tim-3 agonistic antibody and galectin-9 (a Tim-3 natural ligand) significantly upregulated mTOR pathway activity. This was in line with increased accumulation of hypoxia-inducible factor 1 alpha (HIF-1α) and secretion of VEGF and TNF-α. Similar results were obtained in primary human healthy leukocytes. Importantly, in both types of primary cells, Tim-3-mediated effects were compared with those induced by lipopolysaccharide (LPS) and stem cell factor (SCF). Tim-3 induced comparatively moderate responses in both AML cells and healthy leukocytes. However, Tim-3, like LPS, mediated the release of both TNF-α and VEGF, while SCF induced mostly VEGF secretion and did not upregulate TNF-α release.

Abnormal expression of Tim-3 antigen on peripheral blood T cells is associated with progressive disease in osteosarcoma patients

T‐cell immunoglobulin and mucin‐domain‐3‐containing molecule 3 (TIM‐3) plays a pivotal role in immune regulation and has been found in various tumors. However, the prevalence and distribution of Tim‐3 in osteosarcoma (OS) is still unclear. The aim of this study was to investigate the prevalence and distribution of Tim‐3 in OS. Tim‐3 on peripheral T cells from 82 OS patients and 60 healthy controls were examined by flow cytometry. Plasma levels of IL‐2, IFN‐γ, and TNF‐α were measured by ELSIA. Tim‐3 on both CD4⁺ T and CD8⁺ T cells were significantly upregulated in OS patients compared with healthy controls, Tim‐3⁺ CD4⁺ T, and Tim‐3⁺ CD8⁺ T cells were both negatively associated with serum levels of IL‐2 and IFN‐γ and TNF‐α. In addition, Tim‐3 showed similar levels in patients with different tumor sites. Nevertheless, patients with advanced tumor stage, metastasis, and pathological tumor fracture displayed significantly higher Tim‐3 on both CD4⁺ T cells and CD8⁺ T cells than those with early tumor stage, without metastasis and pathological tumor fracture. Moreover, high Tim‐3 on peripheral CD4⁺ T cells or CD8⁺ T were significantly related to poor overall survival (P = 0.014, P = 0.035, respectively). In conclusion, Tim‐3 may be a potential diagnostic and prognostic biomarker for OS progression.

Negative regulation of TIM-3 expression in AML cell line (HL-60) using miR-330-5p

BACKGROUND

Uncontrolled proliferation and accumulation of leukaemic stem cells (LSCs) in bone marrow leads to acute myeloma leukaemia (AML). T cell immunoglobulin and mucine domain (TIM)-3 is a specific surface marker for LSCs and is highly expressed on LSCs compared with normal bone marrow cells, haematopoietic stem cells. Studies have indicated that microRNAs can affect AML progression through targeting different genes expressions like TIM-3. So, based on bioinformatics assessments, we predicted that miR-330-5p may highly inhibit TIM-3 expression. The purpose of the present study was to prove the silencing effect of miR-330-5p on TIM-3 gene expression in AML cell line (HL-60) in vitro.

METHODS

HL-60 cells were cultured in RPMI 1640 supplied with 10% FBS. TIM-3 expression was induced in the cells using phorbol myristate acetate (PMA). The cells were transfected with miR-330-5p and then, the gene and protein expression of TIM-3 were measured using q-RT-PCR and flow-cytometry methods, respectively.

RESULTS

The results of our bioinformatics surveys revealed that miR-330-5p has high predicted ability to silence TIM-3 gene expression. Accordingly, our experiments confirmed that miR-330-5p is able to strongly silence TIM-3 expression (98.15% silencing) in HL-60 cell line (p = 0.0001).

CONCLUSION

According to our results, miR-330-5p has a strong inhibitory effect on TIM-3 expression in AML cell line. Thus, the bioinformatics prediction of Mirwalk and Target Scan softwares for silencing effect of miR-330-5p on TIM-3 is confirmed.

Tim-3 and Tim-4 as the potential targets for antitumor therapy

Both Tim-3 and Tim-4 belong to the T-cell immunoglobulin and mucin domain (Tim) gene family, which plays a critical role in immunoregulation. Tim-3 has been suggested as a negative regulator of anti-tumor immunity due to its function on inducing T cells exhaustion in cancer. In addition to its expression on exhausted T cells, Tim-3 also has been reported to up-regulate on nature killer (NK) cells and promote NK cells functionally exhausted in cancer. While Tim-3 selectively expression on most types of leukemia stem cells, it promotes the progression of acute myeloid leukemia. Recently, data from experimental models of tumor discovered that Tim-3 and Tim-4 up-regulation on tumor associated dendritic cells and macrophages attenuated the anti-tumor effects of cancer vaccines and chemotherapy. Moreover, co-blockage of Tim-3 and PD-1, Tim-3 and CD137, Tim-3 and carcinoembryonic antigen cell adhesion molecule 1 (CEACAM1) could enhance cell-mediated immunity in advanced tumor, and combined treatment with anti-Tim-3 and anti-Tim-4 mAbs further increase the efficacy of cancer vaccines. The therapeutic manipulation of TIM-3 and TIM-4 may provide a novel strategy to improve the clinical efficacy of cancer immunotherapy.