Promotion of tissue inflammation by the immune receptor Tim-3 expressed on innate immune cells

Impairment of Gal-9 and Tim-3 crosstalk between Tregs and Th17 cells drives tobacco smoke-induced airway inflammation

Overexpression of T-cell immunoglobulin and mucin-domain containing-3 (TIM-3) on T cells has been observed in smokers. However, whether and how galectin-9 (Gal-9)/TIM-3 signal between T-regulatory cells (Tregs) and type 17 helper (Th17) cells contributes to tobacco smoke-induced airway inflammation remains unclear. Here, we aimed to explore the role of the Gal-9/TIM-3 signal between Tregs and Th17 cells during chronic tobacco smoke exposure. Tregs phenotype and the expression of TIM-3 on CD4+ T cells were detected in a mouse model of experimental emphysema. The role of TIM-3 in CD4+ T cells was explored in a HAVCR2-/- mouse model and in mice that received recombinant anti-TIM3. The crosstalk between Gal-9 and Tim-3 was evaluated by coculture Tregs with effector CD4+ T cells. We also invested the expression of Gal-9 in Tregs in patients with COPD. Our study revealed that chronic tobacco smoke exposure significantly reduces the frequency of Tregs in the lungs of mice and remarkably shapes the heterogeneity of Tregs by downregulating the expression of Gal-9. We observed a pro-inflammatory but restrained phenotypic transition of CD4+ T cells after tobacco smoke exposure, which was maintained by TIM-3. The restrained phenotype of CD4+ T cells was perturbed when TIM-3 was deleted or neutralised. Tregs from the lungs of mice with emphysema displayed a blunt ability to inhibit the differentiation and proliferation of Th17 cells. The inhibitory function of Tregs was partially restored by using recombinant Gal-9. The interaction between Gal-9 and TIM-3 inhibits the differentiation of Th17 cells and promotes apoptosis of CD4+ T cells, possibly by interfering with the expression of retinoic acid receptor-related orphan receptor gamma t. The expression of Gal-9 in Tregs was reduced in patients with COPD, which was associated with Th17 response and lung function. These findings present a new paradigm that impairment of Gal-9/Tim-3 crosstalk between Tregs and Th17 cells during chronic tobacco smoke exposure promotes tobacco smoke-induced airway/lung inflammation.

Galectin-9 and Tim-3 are upregulated in response to microglial activation induced by the peptide Amyloid-β (25-35)

Galectins are a group of β-galactoside-binding lectins associated with regulating immunological response. In the brains of AD patients and 5xFAD (familial AD) mice, galectin-3 (Gal-3) was highly upregulated and found to be expressed in microglia associated with Aβ plaques. However, the participation of other galectins, specifically galectin-9 (Gal-9) and T-cell immunoglobulin and mucin domain 3 (Tim-3) receptors, are unknown in the inflammatory response. The experimental model of the Aβ25-35 peptide will allow us to study the mechanisms of neuroinflammation and describe the changes in the expression of the Gal-9 and Tim-3 receptor. This study aimed to evaluate whether Aβ25-35 peptide administration into the lateral ventricles of rats upregulated Gal-9 and Tim-3 implicated in the modulation of neuroinflammation. The vehicle or Aβ25-35 peptide (1 μg/μL) was bilaterally administered into the lateral ventricles of the rat, and control group. After the administration of the Aβ25-35 peptide, animals were tested for learning (day 29) and spatial memory (day 30) in the novel object recognition test (NOR). On day 31, hippocampus was examined for morphological changes by Nilss stain, biochemical changes by NO2 and MDA, immunohistochemical analysis by astrocytes (GFAP), microglia (Iba1), Gal-9 and Tim-3, and western blot. Our results show the administration of the Aβ25-35 peptide into the lateral ventricles of rats induce memory impairment in the NOR by increases the oxidative stress and inflammatory response. This result is associated with an upregulation of Gal-9 and Tim-3 predominantly detected in the microglia cells of Aβ25-35-treated rats with respect to the control group. Gal-9 and Tim-3 are upregulated in activated microglia that could modulate the inflammatory response and damage in neurodegenerative processes induced by the Aβ25-35 peptide. Therefore, we suggest that Gal-9 and Tim-3 participate in the inflammatory process induced by the administration of the Aβ25-35 peptide.

The diversity of inhibitory receptor co-expression patterns of exhausted CD8+ T cells in oropharyngeal carcinoma

Exhausted CD8+ T cells (Texs) are characterized by the expression of various inhibitory receptors (IRs), whereas the functional attributes of these co-expressed IRs remain limited. Here, we systematically characterized the diversity of IR co-expression patterns in Texs from both human oropharyngeal squamous cell carcinoma (OPSCC) tissues and syngeneic OPSCC model. Nearly 60% of the Texs population co-expressed two or more IRs, and the number of co-expressed IRs was positively associated with superior exhaustion and cytotoxicity phenotypes. In OPSCC patients, programmed cell death-1 (PD-1) blockade significantly enhanced PDCD1-based co-expression with other IR genes, whereas dual blockades of PD-1 and cytotoxic T lymphocyte-associated protein 4 (CTLA-4) significantly upregulated CTLA4-based co-expression with other IR genes. Collectively, our findings demonstrate that highly diverse IR co-expression is a leading feature of Texs and represents their functional states, which might provide essential clues for the rational selection of immune checkpoint inhibitors in treating OPSCC.

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

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

Macrophage Tim-3 maintains intestinal homeostasis in DSS-induced colitis by suppressing neutrophil necroptosis

T-cell immunoglobulin domain and mucin domain-3 (Tim-3) is a versatile immunomodulator that protects against intestinal inflammation. Necroptosis is a type of cell death that regulates intestinal homeostasis and inflammation. The mechanism(s) underlying the protective role of macrophage Tim-3 in intestinal inflammation is unclear; thus, we investigated whether specific Tim-3 knockdown in macrophages drives intestinal inflammation via necroptosis. Tim-3 protein and mRNA expression were assessed via double immunofluorescence staining and single-cell RNA sequencing (sc-RNA seq), respectively, in the colonic tissues of patients with inflammatory bowel disease (IBD) and healthy controls. Macrophage-specific Tim3-knockout (Tim-3M-KO) mice were generated to explore the function and mechanism of Tim-3 in dextran sodium sulfate (DSS)-induced colitis. Necroptosis was blocked by pharmacological inhibitors of receptor-interacting protein kinase (RIP)1, RIP3, and reactive oxygen species (ROS). Additionally, in vitro experiments were performed to assess the mechanisms of neutrophil necroptosis induced by Tim-3 knockdown macrophages. Although Tim-3 is relatively inactive in macrophages during colon homeostasis, it is highly active during colitis. Compared to those in controls, Tim-3M-KO mice showed increased susceptibility to colitis, higher colitis scores, and increased pro-inflammatory mediator expression. Following the administration of RIP1/RIP3 or ROS inhibitors, a significant reduction in intestinal inflammation symptoms was observed in DSS-treated Tim-3M-KO mice. Further analysis indicated the TLR4/NF-κB pathway in Tim-3 knockdown macrophages mediates the TNF-α-induced necroptosis pathway in neutrophils. Macrophage Tim-3 regulates neutrophil necroptosis via intracellular ROS signaling. Tim-3 knockdown macrophages can recruit neutrophils and induce neutrophil necroptosis, thereby damaging the intestinal mucosal barrier and triggering a vicious cycle in the development of colitis. Our results demonstrate a protective role of macrophage Tim-3 in maintaining gut homeostasis by inhibiting neutrophil necroptosis and provide novel insights into the pathogenesis of IBD.

Evaluation of changes in exhausted T lymphocytes and miRNAs expression in the different trimesters of pregnancy in pregnant women

BACKGROUND

Throughout the three trimesters of a typical pregnancy, we looked at changes in the expression of miRNAs and exhausted T lymphocytes for this study.

METHODS AND RESULTS

Fifty healthy subjects were included in this study. The frequency of exhausted T lymphocytes was measured in isolated PBMCs using flow cytometry. PD-1, TIM-3, and related miRNAs gene expression were assessed using qRT-PCR. The analyses revealed a significant decline in PD-1 and Tim-3 expression in PBMCs from RPL women (p = 0.0003 and p = 0.001, respectively). In addition, PD-1 and TIM-3 expression increased significantly in the 2nd trimester compared with the 1st trimester of healthy pregnant women (p < 0.0001 and p = 0.0002, respectively). PD-1 and TIM-3 expression was down-regulated in the 3rd trimester compared with the 1st and 2nd trimesters. In the present study, we demonstrated that TIM-3+/CD4+, TIM-3+/CD8+, PD-1+/CD4+, and PD-1+/CD8 + exhausted T lymphocytes increased in the circulation of women in the 2nd trimester compared to the 1st and 3rd trimester. In the 3rd trimester, the expression of miR-16-5p increased significantly (p < 0.0001). miR-125a-3p expression was down and upregulated in 2nd (p < 0.0001) and 3rd (p = 0.0007) trimesters compared to 1st trimester, respectively. This study showed a significant elevation of miR-15a-5p in 3rd trimester compared to 1st trimester of pregnant women (p = 0.0002).

CONCLUSIONS

Expression pattern of PD-1 and TIM3 in exhausted T lymphocytes is different not only between normal pregnant and RPL women but also in different trimesters of pregnancy. So, our results showed the role of these markers in the modulation lymphocytes activity in different stages of pregnancy.

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

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

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

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

Immune checkpoint inhibitors in metastatic melanoma therapy (Review)

An increase in the incidence of melanoma has been observed in recent decades, which poses a significant challenge due to its poor prognosis in the advanced and metastatic stages. Previously, chemotherapy and high doses of interleukin-2 were available treatments for melanoma; however, they offered limited survival benefits and were associated with severe toxicities. The treatment of metastatic melanoma has been transformed by new developments in immunotherapy. Immune checkpoint inhibitors (ICIs), monoclonal antibodies that target cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), programmed cell death protein 1 (PD-1) and its ligand, PDL-1, have emerged as promising therapeutic options. Commonly used ICIs, such as ipilimumab, nivolumab and pembrolizumab, have been found to be associated with an improved median overall survival, recurrence-free survival and response rates compared to traditional chemotherapies. Combination therapies involving different types of ICIs, such as anti-PD1 with anti-CTLA-4, have further enhanced the overall survival and response rates by targeting various phases of T-cell activation. Additionally, the development of novel biomarkers has facilitated the assessment of responses to ICI therapy, with tissue and serum-based prognostic and predictive biomarkers now available. The increased response observed with ICIs also provides potential for immune-related adverse effects on various organ systems. Further research is required to evaluate the efficacy and safety of various combinations of ICIs, while ongoing clinical trials explore the potential of newer ICIs. Concerns regarding the development of resistance to ICIs also warrant attention. The present review summarizes and discusses the advent of ICIs with a marked significant breakthrough in the treatment of metastatic melanoma, providing improved outcomes compared to traditional therapies.

The Use of Immune Regulation in Treating Head and Neck Squamous Cell Carcinoma (HNSCC)

Immunotherapy has emerged as a promising new treatment modality for head and neck cancer, offering the potential for targeted and effective cancer management. Squamous cell carcinomas pose significant challenges due to their aggressive nature and limited treatment options. Conventional therapies such as surgery, radiation, and chemotherapy often have limited success rates and can have significant side effects. Immunotherapy harnesses the power of the immune system to recognize and eliminate cancer cells, and thus represents a novel approach with the potential to improve patient outcomes. In the management of head and neck squamous cell carcinoma (HNSCC), important contributions are made by immunotherapies, including adaptive cell therapy (ACT) and immune checkpoint inhibitor therapy. In this review, we are focusing on the latter. Immune checkpoint inhibitors target proteins such as programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) to enhance the immune response against cancer cells. The CTLA-4 inhibitors, such as ipilimumab and tremelimumab, have been approved for early-stage clinical trials and have shown promising outcomes in terms of tumor regression and durable responses in patients with advanced HNSCC. Thus, immune checkpoint inhibitor therapy holds promise in overcoming the limitations of conventional therapies. However, further research is needed to optimize treatment regimens, identify predictive biomarkers, and overcome potential resistance mechanisms. With ongoing advancements in immunotherapy, the future holds great potential for transforming the landscape of oral tumor treatment and providing new hope for patients.

Tim-3 deficiency aggravates cadmium nephrotoxicity via regulation of NF-κB signaling and mitochondrial damage

Kidney is the target organ of serious cadmium injury. Kidney damage caused by cadmium exposure is greatly influenced by the inflammatory response and mitochondrial damage. T cell immunoglobulin domain and mucin domain 3 (Tim-3) is an essential protein that functions as a negative immunological checkpoint to regulate inflammatory responses. Mice were given cadmium treatments at various dosages (0, 1.5, 3, 4.5 mg/kg) and times (0, 3, 5, 7 days) to assess the effects of cadmium on kidney damage. We found that the optimal way to induce kidney injury in mice was to inject 4.5 mg/kg of cadmium intraperitoneally for five days. It is interesting that giving mice 4.5 mg/kg of cadmium intravenously for seven days drastically lowered their survival rate. After cadmium exposure, Tim-3 knockout mice exhibited higher blood concentrations of urea nitrogen and creatinine compared to control mice. Tim-3 impacted the expression of oxidative stress-associated genes such as UDP glucuronosyltransferase family 1 member A9 (Ugt1a9), oxidative stress-induced growth inhibitor 2 (Osgin2), and S100 calcium binding protein A8 (S100a8), according to RNA-seq and real-time RT-PCR data. Tim-3 deficiency also resulted in activated nuclear factor-kappa B (NF-κB) signaling pathway. The NF-κB inhibitor 2-[(aminocarbonyl)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide (TPCA-1) significantly alleviated cell apoptosis, oxidative stress response, and renal tubule inflammation in Tim-3 knockout mice exposed to cadmium. Furthermore, cadmium caused obvious B-cell lymphoma protein 2 (Bcl-2)-associated X (Bax) translocation from cytoplasm to mitochondria, which can be inhibited by TPCA-1. In conclusion, Tim-3 prevented mitochondrial damage and NF-κB signaling activation, hence providing protection against cadmium nephrotoxicity.

Expression of B7-H3 and TIM-3 in gastric-type endocervical adenocarcinoma: prevalence, association with PD-L1 expression, and prognostic significance

Gastric-type endocervical adenocarcinoma (GEA) is the second most common subtype of endocervical adenocarcinoma and has a poor prognosis. Anti-programmed death-1 and anti-programmed death-ligand 1 (PD-L1) inhibitors have emerged as a major treatment option for GEA; however, data on the expression of other immune checkpoints in GEA are limited. We analyzed the expression of T-cell immunoglobulin and mucin-domain containing-3 (TIM-3) and B7 homolog 3 protein (B7-H3) in 58 GEA and investigated their prognostic significance as well as association with PD-L1 expression and other known prognostic factors. Applying the tumor proportion score (TPS) with a cutoff of 1%, B7-H3 and TIM-3 were present in 48.3% and 17.2% of cases, respectively. Applying the combined positive score (CPS) with a cutoff of 1, TIM-3 expression was present in 70.7% of cases. Moreover, the expression of three checkpoints (B7-H3, TIM-3, and PD-L1) was incompletely overlapping. Patients with B7-H3 positive tumors (by TPS) or TIM-3 positive tumors (by TPS) had significantly worse recurrence-free survival (RFS) and overall survival (OS) (log-rank). Using CPS, patients with TIM-3 positive tumors showed significantly worse RFS (log-rank). Similarly, B7-H3 positivity (by TPS) and TIM-3 positivity (by TPS) were associated with worse RFS and OS in univariate analysis. TIM-3 positivity (by CPS) was associated with worse RFS in univariate analysis and the final Cox multivariate analysis. In conclusion, our results show that (1) B7-H3 and TIM-3 are frequently expressed in GEA and their expression overlaps incompletely with PD-L1; and (2) both B7-H3 and TIM-3 are independent negative prognostic markers in GEA.

Targeting the immune microenvironment for ovarian cancer therapy

Ovarian cancer (OC) is an aggressive malignancy characterized by a complex immunosuppressive tumor microenvironment (TME). Immune checkpoint inhibitors have emerged as a breakthrough in cancer therapy by reactivating the antitumor immune response suppressed by tumor cells. However, in the case of OC, these inhibitors have failed to demonstrate significant improvements in patient outcomes, and existing biomarkers have not yet identified promising subgroups. Consequently, there remains a pressing need to understand the interplay between OC tumor cells and their surrounding microenvironment to develop effective immunotherapeutic approaches. This review aims to provide an overview of the OC TME and explore its potential as a therapeutic strategy. Tumor-infiltrating lymphocytes (TILs) are major actors in OC TME. Evidence has been accumulating regarding the spontaneous TILS response against OC antigens. Activated T-helpers secrete a wide range of inflammatory cytokines with a supportive action on cytotoxic T-cells. Simultaneously, mature B-cells are recruited and play a significant antitumor role through opsonization of target antigens and T-cell recruitment. Macrophages also form an important subset of innate immunity (M1-macrophages) while participating in the immune-stimulation context. Finally, OC has shown to engage a significant natural-killer-cells immune response, exerting direct cytotoxicity without prior sensitization. Despite this initial cytotoxicity, OC cells develop various strategies to induce an immune-tolerant state. To this end, multiple immunosuppressive molecules are secreted to impair cytotoxic cells, recruit regulatory cells, alter antigen presentation, and effectively evade immune response. Consequently, OC TME is predominantly infiltrated by immunosuppressive cells such as FOXP3+ regulatory T-cells, M2-polarized macrophages and myeloid-derived suppressor cells. Despite this strong immunosuppressive state, PD-1/PD-L1 inhibitors have failed to improve outcomes. Beyond PD-1/PD-L1, OC expresses multiple other immune checkpoints that contribute to immune evasion, and each representing potential immune targets. Novel immunotherapies are attempting to overcome the immunosuppressive state and induce specific immune responses using antibodies adoptive cell therapy or vaccines. Overall, the OC TME presents both opportunities and obstacles. Immunotherapeutic approaches continue to show promise, and next-generation inhibitors offer exciting opportunities. However, tailoring therapies to individual immune characteristics will be critical for the success of these treatments.

Deletion of the protein tyrosine phosphatase PTPN22 for adoptive T cell therapy facilitates CTL effector function but promotes T cell exhaustion

BACKGROUND

Adoptive cell therapy (ACT) is a promising strategy for treating cancer, yet it faces several challenges such as lack of long-term protection due to T cell exhaustion induced by chronic TCR stimulation in the tumor microenvironment. One benefit of ACT, however, is that it allows for cellular manipulations, such as deletion of the phosphotyrosine phosphatase non-receptor type 22 (PTPN22), which improves CD8+ T cell antitumor efficacy in ACT. We tested whether Ptpn22KO cytolytic T cells (CTLs) were also more effective than Ptpn22WT CTL in controlling tumors in scenarios that favor T cell exhaustion.

METHODS

Tumor control by Ptpn22WT and Ptpn22KO CTL was assessed following adoptive transfer of low numbers of CTL to mice with subcutaneously implanted MC38 tumors. Tumor infiltrating lymphocytes were isolated for analysis of effector functions. An in vitro assay was established to compare CTL function in response to acute and chronic restimulation with antigen-pulsed tumor cells. The expression of effector and exhaustion-associated proteins by Ptpn22WT and Ptpn22KO T cells was followed over time in vitro and in vivo using the ID8 tumor model. Finally, the effect of PD-1 and TIM-3 blockade on Ptpn22KO CTL tumor control was assessed using monoclonal antibodies and CRISPR/Cas9-mediated knockout.

RESULTS

Despite having improved effector function at the time of transfer, Ptpn22KO CTL became more exhausted than Ptpn22WT CTL, characterized by more rapid loss of effector functions, and earlier and higher expression of inhibitory receptors (IRs), particularly the terminal exhaustion marker TIM-3. TIM-3 expression, under the control of the transcription factor NFIL3, was induced by IL-2 signaling which was enhanced in Ptpn22KO cells. Antitumor responses of Ptpn22KO CTL were improved following PD-1 blockade in vivo, yet knockout or antibody-mediated blockade of TIM-3 did not improve but further impaired tumor control, indicating TIM-3 signaling itself did not drive the diminished function seen in Ptpn22KO CTL.

CONCLUSIONS

This study questions whether TIM-3 plays a role as an IR and highlights that genetic manipulation of T cells for ACT needs to balance short-term augmented effector function against the risk of T cell exhaustion in order to achieve longer-term protection.

Extracellular vesicles derived from nasopharyngeal carcinoma induce the emergence of mature regulatory dendritic cells using a galectin-9 dependent mechanism

Nasopharyngeal carcinoma-derived small extracellular vesicles (NPCSEVs) have an immunosuppressive impact on the tumour microenvironment. In this study, we investigated their influence on the generation of tolerogenic dendritic cells and the potential involvement of the galectin-9 (Gal9) they carry in this process. We analysed the phenotype and immunosuppressive properties of NPCSEVs and explored the ability of DCs exposed to NPCSEVs (NPCSEV-DCs) to regulate T cell proliferation. To assess their impact at the pathophysiological level, we performed real-time fluorescent chemoattraction assays. Finally, we analysed phenotype and immunosuppressive functions of NPCSEV-DCs using a proprietary anti-Gal9 neutralising antibody to assess the role of Gal9 in this effect. We described that NPCSEV-DCs were able to inhibit T cell proliferation despite their mature phenotype. These mature regulatory DCs (mregDCs) have a specific oxidative metabolism and secrete high levels of IL-4. Chemoattraction assays revealed that NPCSEVs could preferentially recruit NPCSEV-DCs. Finally, and very interestingly, the reduction of the immunosuppressive function of NPCSEV-DCs using an anti-Gal9 antibody clearly suggested an important role for vesicular Gal9 in the induction of mregDCs. These results revealed for the first time that NPCSEVs promote the emergence of mregDCs using a galectin-9 dependent mechanism and open new perspectives for antitumour immunotherapy targeting NPCSEVs.

Immunomodulation exerted by galectins: a land of opportunity in rare cancers

Rare cancers represent only 5% of newly diagnosed malignancies. However, in some cases, they account for up to 50% of the deaths attributed to cancer in their corresponding organ. Part of the reason is that treatment options are generally quite limited, non-specific, and very often, only palliative. Needless to say, research for tailored treatments is warranted. Molecules that exert immunomodulation of the tumor microenvironment are attractive drug targets. One such group is galectins. Thus, in this review we summarize the current knowledge about galectin-mediated immunomodulation in rare cancers, highlighting the research opportunities in each case.

A new emerging target in cancer immunotherapy: Galectin-9 (LGALS9)

Over the past few decades, advances in immunological knowledge have led to the identification of novel immune checkpoints, reinvigorating cancer immunotherapy. Immunotherapy, represented by immune checkpoint inhibitors, has become the leader in the precision treatment of cancer, bringing a new dawn to the treatment of most cancer patients. Galectin-9 (LGALS9), a member of the galectin family, is a widely expressed protein involved in immune regulation and tumor pathogenesis, and affects the prognosis of various types of cancer. Galectin-9 regulates immune homeostasis and tumor cell survival through its interaction with its receptor Tim-3. In the review, based on a brief description of the signaling mechanisms and immunomodulatory activities of galectin-9 and Tim-3, we summarize the targeted expression patterns of galectin-9 in a variety of malignancies and the promising mechanisms of anti-galectin-9 therapy in stimulating anti-tumor immune responses.

Immunotherapy with Monoclonal Antibodies for Acute Myeloid Leukemia: A Work in Progress

In the last few years, molecularly targeted agents and immune-based treatments (ITs) have significantly changed the landscape of anti-cancer therapy. Indeed, ITs have been proven to be very effective when used against metastatic solid tumors, for which outcomes are extremely poor when using standard approaches. Such a scenario has only been partially reproduced in hematologic malignancies. In the context of acute myeloid leukemia (AML), as innovative drugs are eagerly awaited in the relapsed/refractory setting, different ITs have been explored, but the results are still unsatisfactory. In this work, we will discuss the most important clinical studies to date that adopt ITs in AML, providing the basis to understand how this approach, although still in its infancy, may represent a promising therapeutic tool for the future treatment of AML patients.

Targeting LAG-3, TIM-3, and TIGIT for cancer immunotherapy

In one decade, immunotherapy based on immune checkpoint blockades (ICBs) has become a new pillar of cancer treatment following surgery, radiation, chemotherapy, and targeted therapies. However, not all cancer patients benefit from single or combination therapy with anti-CTLA-4 and anti-PD-1/PD-L1 monoclonal antibodies. Thus, an increasing number of immune checkpoint proteins (ICPs) have been screened and their effectiveness evaluated in preclinical and clinical trials. Lymphocyte activation gene-3 (LAG-3), T cell immunoglobulin and mucin-domain-containing-3 (TIM-3), and T cell immunoreceptor with immunoglobulin and tyrosine-based inhibitory motif (ITIM) domain (TIGIT) constitute the second wave of immunotherapy targets that show great promise for use in the treatment of solid tumors and leukemia. To promote the research and clinical application of ICBs directed at these targets, we summarize their discovery, immunotherapy mechanism, preclinical efficiency, and clinical trial results in this review.

Immune checkpoint molecule Tim-3 promotes NKT cell apoptosis and predicts poorer prognosis in Sepsis

BACKGROUND

Sepsis is a leading cause of death among critically ill patients, which is defined as life-threatening organ dysfunction caused by a deregulated host immune response to infection. Immune checkpoint molecule Tim-3 plays important and complex roles in regulating immune responses and in inducing immune tolerance. Although immune checkpoint blockade would be expected as a promising therapeutic strategy for sepsis, but the underlying mechanism remain unknown, especially under clinical conditions.

METHODS

Tim-3 expression and apoptosis in NKT cells were compared in septic patients (27 patients with sepsis and 28 patients with septic shock). Phenotypic and functional characterization of Tim-3+ NKT cells were analysed, and then the relationship between Tim-3 + NKT cells and clinical prognosis were investigated in septic patients. α-lactose (Tim-3/Galectin-9 signalling inhibitor) and Tim-3 mutant mice (targeting mutation of the Tim-3 cytoplasmic domain) were utilized to evaluate the protective effect of Tim-3 signalling blockade following septic challenge.

RESULTS

There is a close correlation between Tim-3 expression and the functional status of NKT cells in septic patients, Upregulated Tim-3 expression promoted NKT cell activation and apoptosis during the early stage of sepsis, and it was associated with worse disease severity and poorer prognosis in septic patients. Blockade of the Tim-3/Galectin-9 signal axis using α-lactose inhibited in vitro apoptosis of NKT cells isolated from septic patients. Impaired activity of Tim-3 protected mice following septic challenge.

CONCLUSIONS

Overall, these findings demonstrated that immune checkpoint molecule Tim-3 in NKT cells plays a critical role in the immunopathogenesis of septic patients. Blockade of immune checkpoint molecule Tim-3 may be a promising immunomodulatory strategy in future clinical practice for the management of sepsis.

The role of macrophages polarization in sepsis-induced acute lung injury

Sepsis presents as a severe infectious disease frequently documented in clinical settings. Characterized by its systemic inflammatory response syndrome, sepsis has the potential to trigger multi-organ dysfunction and can escalate to becoming life-threatening. A common fallout from sepsis is acute lung injury (ALI), which often progresses to acute respiratory distress syndrome (ARDS). Macrophages, due to their significant role in the immune system, are receiving increased attention in clinical studies. Macrophage polarization is a process that hinges on an intricate regulatory network influenced by a myriad of signaling molecules, transcription factors, epigenetic modifications, and metabolic reprogramming. In this review, our primary focus is on the classically activated macrophages (M1-like) and alternatively activated macrophages (M2-like) as the two paramount phenotypes instrumental in sepsis' host immune response. An imbalance between M1-like and M2-like macrophages can precipitate the onset and exacerbate the progression of sepsis. This review provides a comprehensive understanding of the interplay between macrophage polarization and sepsis-induced acute lung injury (SALI) and elaborates on the intervention strategy that centers around the crucial process of macrophage polarization.

Biomarkers for immune checkpoint inhibition in sarcomas - are we close to clinical implementation?

Sarcomas are a group of diverse and complex cancers of mesenchymal origin that remains poorly understood. Recent developments in cancer immunotherapy have demonstrated a potential for better outcomes with immune checkpoint inhibition in some sarcomas compared to conventional chemotherapy. Immune checkpoint inhibitors (ICIs) are key agents in cancer immunotherapy, demonstrating improved outcomes in many tumor types. However, most patients with sarcoma do not benefit from treatment, highlighting the need for identification and development of predictive biomarkers for response to ICIs. In this review, we first discuss United States (US) Food and Drug Administration (FDA)-approved and European Medicines Agency (EMA)-approved biomarkers, as well as the limitations of their use in sarcomas. We then review eight potential predictive biomarkers and rationalize their utility in sarcomas. These include gene expression signatures (GES), circulating neutrophil-to-lymphocyte ratio (NLR), indoleamine 2,3-dioxygenase (IDO), lymphocyte activation gene 3 (LAG-3), T cell immunoglobin and mucin domain-containing protein 3 (TIM-3), TP53 mutation status, B cells, and tertiary lymphoid structures (TLS). Finally, we discuss the potential for TLS as both a predictive and prognostic biomarker for ICI response in sarcomas to be implemented in the clinic.

How can Cytokine-induced killer cells overcome CAR-T cell limits

The successful treatment of patients affected by B-cell malignancies with Chimeric Antigen Receptor (CAR)-T cells represented a breakthrough in the field of adoptive cell therapy (ACT). However, CAR-T therapy is not an option for every patient, and several needs remain unmet. In particular, the production of CAR-T cells is expensive, labor-intensive and logistically challenging; additionally, the toxicities deriving from CAR-T cells infusion, such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), have been documented extensively. Alternative cellular therapy products such as Cytokine-induced killer (CIK) cells have the potential to overcome some of these obstacles. CIK cells are a heterogeneous population of polyclonal CD3+CD56+ T cells with phenotypic and functional properties of NK cells. CIK cell cytotoxicity is exerted in a major histocompatibility complex (MHC)-unrestricted manner through the engagement of natural killer group 2 member D (NKG2D) molecules, against a wide range of hematological and solid tumors without the need for prior antigen exposure or priming. The foremost potential of CIK cells lies in the very limited ability to induce graft-versus-host disease (GvHD) reactions in the allogeneic setting. CIK cells are produced with a simple and extremely efficient expansion protocol, which leads to a massive expansion of effector cells and requires a lower financial commitment compared to CAR-T cells. Indeed, CAR-T manufacturing involves the engineering with expensive GMP-grade viral vectors in centralized manufacturing facilities, whereas CIK cell production is successfully performed in local academic GMP facilities, and CIK cell treatment is now licensed in many countries. Moreover, the toxicities observed for CAR-T cells are not present in CIK cell-treated patients, thus further reducing the costs associated with hospitalization and post-infusion monitoring of patients, and ultimately encouraging the delivery of cell therapies in the outpatient setting. This review aims to give an overview of the limitations of CAR-T cell therapy and outline how the use of CIK cells could overcome such drawbacks thanks to their unique features. We highlight the undeniable advantages of using CIK cells as a therapeutic product, underlying the opportunity for further research on the topic.

Role of Next Generation Immune Checkpoint Inhibitor (ICI) Therapy in Philadelphia Negative Classic Myeloproliferative Neoplasm (MPN): Review of the Literature

The Philadelphia chromosome-negative (Ph-) myeloproliferative neoplasms (MPNs), which include essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis (MF), are enduring and well-known conditions. These disorders are characterized by the abnormal growth of one or more hematopoietic cell lineages in the body's stem cells, leading to the enlargement of organs and the manifestation of constitutional symptoms. Numerous studies have provided evidence indicating that the pathogenesis of these diseases involves the dysregulation of the immune system and the presence of chronic inflammation, both of which are significant factors. Lately, the treatment of cancer including hematological malignancy has progressed on the agents aiming for the immune system, cytokine environment, immunotherapy agents, and targeted immune therapy. Immune checkpoints are the molecules that regulate T cell function in the tumor microenvironment (TME). The first line of primary immune checkpoints are programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1), and cytotoxic T-lymphocyte antigen-4 (CTLA-4). Immune checkpoint inhibitor therapy (ICIT) exerts its anti-tumor actions by blocking the inhibitory pathways in T cells and has reformed cancer treatment. Despite the impressive clinical success of ICIT, tumor internal resistance poses a challenge for oncologists leading to a low response rate in solid tumors and hematological malignancies. A Phase II trial on nivolumab for patients with post-essential thrombocythemia myelofibrosis, primary myelofibrosis, or post-polycythemia myelofibrosis was performed (Identifier: NCT02421354). This trial tested the efficacy of a PD-1 blockade agent, namely nivolumab, but was terminated prematurely due to adverse events and lack of efficacy. A multicenter, Phase II, single-arm open-label study was conducted including pembrolizumab in patients with primary thrombocythemia, post-essential thrombocythemia or post-polycythemia vera myelofibrosis that were ineligible for or were previously treated with ruxolitinib. This study showed that pembrolizumab treatment did not have many adverse events, but there were no pertinent clinical responses hence it was terminated after the first stage was completed. To avail the benefits from immunotherapy, the paradigm has shifted to new immune checkpoints in the TME such as lymphocyte activation gene-3 (LAG-3), T cell immunoglobulin and mucin domain 3 (TIM-3), T cell immunoglobulin and ITIM domain (TIGIT), V-domain immunoglobulin-containing suppressor of T cell activation (VISTA), and human endogenous retrovirus-H long terminal repeat-associating protein 2 (HHLA2) forming the basis of next-generation ICIT. The primary aim of this article is to underscore and elucidate the significance of next-generation ICIT in the context of MPN. Specifically, we aim to explore the potential of monoclonal antibodies as targeted immunotherapy and the development of vaccines targeting specific MPN epitopes, with the intent of augmenting tumor-related immune responses. It is anticipated that these therapeutic modalities rooted in immunotherapy will not only expand but also enhance the existing treatment regimens for patients afflicted with MPN. Preliminary studies from our laboratory showed over-expressed MDSC and over-expressed VISTA in MDSC, and in progenitor and immune cells directing the need for more clinical trials using next-generation ICI in the treatment of MPN.

Human galectin-9 potently enhances SARS-CoV-2 replication and inflammation in airway epithelial cells

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has caused a global economic and health crisis. Recently, plasma levels of galectin-9 (Gal-9), a β-galactoside-binding lectin involved in immune regulation and viral immunopathogenesis, were reported to be elevated in the setting of severe COVID-19 disease. However, the impact of Gal-9 on SARS-CoV-2 infection and immunopathology remained to be elucidated. In this study, we demonstrate that Gal-9 treatment potently enhances SARS-CoV-2 replication in human airway epithelial cells (AECs), including immortalized AECs and primary AECs cultured at the air-liquid interface. Gal-9-glycan interactions promote SARS-CoV-2 attachment and entry into AECs in an angiotensin-converting enzyme 2 (ACE2)-dependent manner, enhancing the binding of the viral spike protein to ACE2. Transcriptomic analysis revealed that Gal-9 and SARS-CoV-2 infection synergistically induced the expression of key pro-inflammatory programs in AECs, including the IL-6, IL-8, IL-17, EIF2, and TNFα signaling pathways. Our findings suggest that manipulation of Gal-9 should be explored as a therapeutic strategy for SARS-CoV-2 infection.

The TLR/MyD88 signalling cascade in inflammation and gastric cancer: the immune regulatory network of Helicobacter pylori

Helicobacter pylori-induced chronic gastritis represents a well-established risk factor for gastric cancer (GC). However, the mechanism by which chronic inflammation caused by H. pylori induces the development of GC is unclear. H. pylori can influence host cell signalling pathways to induce gastric disease development and mediate cancer promotion and progression. Toll-like receptors (TLRs), as pattern recognition receptors (PRRs), play a key role in the gastrointestinal innate immune response, and their signalling has been implicated in the pathogenesis of an increasing number of inflammation-associated cancers. The core adapter myeloid differentiation factor-88 (MyD88) is shared by most TLRs and functions primarily in H. pylori-triggered innate immune signalling. MyD88 is envisioned as a potential target for the regulation of immune responses and is involved in the regulation of tumourigenesis in a variety of cancer models. In recent years, the TLR/MyD88 signalling pathway has received increasing attention for its role in regulating innate and adaptive immune responses, inducing inflammatory activation and promoting tumour formation. In addition, TLR/MyD88 signalling can manipulate the expression of infiltrating immune cells and various cytokines in the tumour microenvironment (TME). In this review, we discuss the pathogenetic regulatory mechanisms of the TLR/MyD88 signalling cascade pathway and its downstream molecules in H. pylori infection-induced-associated GC. The focus is to elucidate the immunomolecular mechanisms of pathogen recognition and innate immune system activation of H. pylori in the TME of inflammation-associated GC. Ultimately, this study will provide insight into the mechanism of H. pylori-induced chronic inflammation-induced GC development and provide thoughts for GC prevention and treatment strategies.

Immunotherapeutic Approaches for the Treatment of Glioblastoma Multiforme: Mechanism and Clinical Applications

Glioma is one of the most aggressive types of primary brain tumor with a high-grade glioma known as glioblastoma multiforme (GBM). Patients diagnosed with GBM usually have an overall survival rate of less than 18 months after conventional therapy. This bleak prognosis underlines the need to consider new therapeutic interventions for GBM treatment to overcome current treatment limitations. By highlighting different immunotherapeutic approaches currently in preclinical and clinical trials, including immune checkpoint inhibitors, chimeric antigen receptors T cells, natural killer cells, vaccines, and combination therapy, this review aims to discuss the mechanisms, benefits, and limitations of immunotherapy in treating GBM patients.

Checkpoint Inhibitors in Acute Myeloid Leukemia

The prognosis of acute myeloid leukemia (AML) remains unsatisfactory. Among the reasons for the poor response to therapy and high incidence of relapse, there is tumor cell immune escape, as AML blasts can negatively influence various components of the immune system, mostly weakening T-cells. Since leukemic cells can dysregulate immune checkpoints (ICs), receptor-based signal transductors that lead to the negative regulation of T-cells and, eventually, to immune surveillance escape, the inhibition of ICs is a promising therapeutic strategy and has led to the development of so-called immune checkpoint inhibitors (ICIs). ICIs, in combination with conventional chemotherapy, hypomethylating agents or targeted therapies, are being increasingly tested in cases of AML, but the results reported are often conflicting. Here, we review the main issues concerning the immune system in AML, the main pathways leading to immune escape and the results obtained from clinical trials of ICIs, alone or in combination, in newly diagnosed or relapsed/refractory AML.

T-cell immunoglobulin and mucin-domain containing-3 (TIM-3): Solving a key puzzle in autoimmune diseases

Dysfunctional immune cells participate in the pathogenesis of a variety of autoimmune diseases, although the specific mechanisms remain elusive and effective clinical interventions are lacking. Recent research on immune checkpoint molecules has revealed significant expression of T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3) on the surfaces of various immune cells. These include different subsets of T cells, macrophages, dendritic cells, natural killer cells, and mast cells. Further investigation into its protein structure, ligands, and intracellular signaling pathway activation mechanisms has found that TIM-3, by binding with different ligands, is involved in the regulation of crucial biological processes such as proliferation, apoptosis, phenotypic transformation, effector protein synthesis, and cellular interactions of various immune cells. The TIM-3-ligand axis plays a pivotal role in the pathogenesis of numerous conditions, including autoimmune diseases, infections, cancers, transplant rejection, and chronic inflammation. This article primarily focuses on the research findings of TIM-3 in the field of autoimmune diseases, with a special emphasis on the structure and signaling pathways of TIM-3, its types of ligands, and the potential mechanisms implicated in systemic lupus erythematosus, multiple sclerosis, rheumatoid arthritis, as well as other autoimmune diseases and chronic inflammation. The latest research results in the field of immunology suggest that TIM-3 dysfunction affects various immune cells and participates in the pathogenesis of diseases. Monitoring the activity of its receptor-ligand axis can serve as a novel biological marker for disease clinical diagnosis and prognosis evaluation. More importantly, the TIM-3-ligand axis and the downstream signaling pathway molecules may become key targets for targeted intervention treatment of autoimmune-related diseases.

TIM-3 increases the abundance of type-2 dendritic cells during Leishmania donovani infection by enhancing IL-10 production via STAT3

The outcome of the disease visceral leishmaniasis (VL), caused by Leishmania donovani (LD), largely relies on the relative dominance of host-protective type-1 T helper (Th1) cell response versus disease-promoting type-2 T helper (Th2) cell response. The Th1 and Th2 responses, in turn, are believed to be elicited by type-1 conventional dendritic cells (cDC1) and type-2 conventional DCs (cDC2), respectively. However, it is still unknown which DC subtype (cDC1 or cDC2) predominates during chronic LD infection and the molecular mechanism governing such occurrence. Here we report that in chronically infected mice, the splenic cDC1-cDC2 balance shifted toward the cDC2 subtype and that the receptor T cell immunoglobulin and mucin protein-3 (TIM-3) expressed by DCs played a key role in mediating this effect. Transfer of TIM-3-silenced DCs in fact prevented the predominance of the cDC2 subtype in mice with chronic LD infection. We also found that LD actually upregulated TIM-3 expression on DCs by triggering a TIM-3-mediated signaling pathway STAT3 (signal transducer and activator of transcription 3)→interleukin (IL)-10→c-Src→transcription factors Ets1, Ets2, USF1, and USF2. Notably, TIM-3 promoted STAT3 activation via a non-receptor tyrosine kinase Btk. Adoptive transfer experiments further demonstrated a critical role for STAT3-driven TIM-3 upregulation on DCs in increasing cDC2 abundance in chronically infected mice, which ultimately aided disease pathogenesis by augmenting Th2 responses. These findings document a new immunoregulatory mechanism contributing to disease pathology during LD infection and define TIM-3 as a key mediator of this process.

Tackling of Immunorefractory Tumors by Targeting Alternative Immune Checkpoints

Physiologically, well known or traditional immune checkpoints (ICs), such as CTLA-4 and PD-1, are in place to promote tolerance to self-antigens and prevent generation of autoimmunity. In cancer, the ICs are effectively engaged by the tumor cells or stromal ells from the tumor microenvironment through expression of cognate ligands for the ICs present on the cell surface of CD8+ T lymphocytes. The ligation of ICs on CD8+ T lymphocytes triggers inhibitory signaling pathways, leading to quiescence or an exhaustion of CD8+ T lymphocytes. This results in failure of immunotherapy. To overcome this, several FDA-approved therapeutic antibodies are available, but the clinical outcome is quite variable due to the resistance encountered through upregulated expression of alternate ICs such as VISTA, LAG-3, TIGIT and TIM-3. This review focuses on the roles played by the traditional as well as alternate ICs and the contribution of associated signaling pathways in generating such resistance to immunotherapy. Combinatorial targeting of traditional and alternate ICs might be beneficial for immune-refractory tumors.

Activation of CD3+TIM3+ T Cells Contributes to Excessive Inflammatory Response During Glucocorticoid Treatment

Glucocorticoids (GCs) are widely used to treat autoimmune and inflammatory diseases, but recent research has challenged the notion that GCs are universally anti-inflammatory. In this study, we investigated the effects of long-term GC exposure on circulating T cells in a retrospective cohort of 5,476 patients with primary glomerular diseases. Our results revealed that GCs altered the composition pattern of circulating leukocytes and the correlation between circulating lymphocytes and serum cytokines in response to infections, as well as the subsets of CD4+ T cells. Specifically, GCs promoted the loss of CD4+ T cells and increased the proportions of CD3+TIM3+ T cells in response to infections, which correlated with the expression of serum inflammatory cytokines, such as IFNG and IL-10. Using animal models of cecal ligation and puncture, we demonstrated that long-term GC exposure exacerbated apoptosis of CD4+ T cells and cytokine storm during sepsis, which was mechanistically linked to the increase of CD3+TIM3+ T cells. Notably, we found that CD3+TIM3+ T cells expressed high levels of multiple cytokine genes during infections, suggesting a potent role of TIM3 in the regulation of T cell biology. In vitro studies further showed that engagement of anti-TIM3 treatment enhanced the inflammatory activity of CD3+ T cells. Our findings suggest a causal relationship between chronic exposure to GCs and an excessive inflammatory response mediated by T cells during infections, which is, at least partly, driven by dysregulation of CD3+TIM3+ T cells.

Emerging Targets for Modulation of Immune Response and Inflammation in Stroke

The inflammatory and immunological responses play a significant role after stroke. The innate immune activation stimulated by microglia during stroke results in the migration of macrophages and lymphocytes into the brain and are responsible for tissue damage. The immune response and inflammation following stroke have no defined targets, and the intricacies of the immunological and inflammatory processes are only partially understood. Innate immune cells enter the brain and meninges during the acute phase, which can cause ischemia damage. Activation of systemic immunity is caused by danger signals sent into the bloodstream by injured brain cells, which is followed by a significant immunodepression that encourages life-threatening infections. Neuropsychiatric sequelae, a major source of post-stroke morbidity, may be induced by an adaptive immune response that is initiated by antigen presentation during the chronic period and is directed against the brain. Thus, the current review discusses the role of immune response and inflammation in stroke pathogenesis, their role in the progression of injury during the stroke, and the emerging targets for the modulation of the mechanism of immune response and inflammation that may have possible therapeutic benefits against stroke.

Decreased expression of ADAM10 on monocytes is associated with chronic allograft dysfunction in kidney transplant recipients

BACKGROUND

Chronic allograft dysfunction (CAD) is a common cause of allograft loss in kidney transplant recipients (KTRs). Our previous study found that elevated serum soluble T cell immunoglobulin mucin-3 (sTim-3) was positively associated with the severity of CAD in KTRs. sTim-3 was reported to be generated from ADAM10/ADAM17-mediated ectodomain shedding of membrane Tim-3 (mTim-3) in humans. However, whether mTim-3 shedding-related molecules participate in the progression of CAD remains unknown. Here, we explored the relationships between different forms of Tim-3, including mTim-3 on different peripheral blood cell subsets, serum and urine sTim-3, and ADAM10/17 expression and active status to investigate their roles in CAD.

METHODS

63 KTRs with stable grafts, 91 KTRs with CAD and 42 healthy controls (HCs) were enrolled. Total Tim-3, pADAM10/17 and mADAM10/17 proteins were semiquantified by western blot. Serum and urine sTim-3 concentrations were determined by ELISA. mTim-3 and ADAM10/17 expression on leukocyte subpopulations was determined by flow cytometry.

RESULTS

The KTR groups displayed significantly higher levels of urine sTim-3 pg/μmol creatinine than the HC group, while no difference was found between the two KTR groups. KTRs with CAD presented reduced nonactive pADAM10 protein but unaltered active mADAM10 when compared to the Stable group; no difference was found between the KTR groups regarding total Tim-3 and p/m ADAM17 protein levels. In addition, the CAD group showed lower mTim-3 expression on BDCA3⁺ DC than the Stable group; no other difference was observed in its expression on B, T, NK, NKT, monocyte subsets and other DC subsets among groups. With the deterioration of allograft function, ADAM10 expression densities on classical, intermediate, and non-classical monocytes were significantly decreased. Correlation analyses revealed that eGFR and serum sTim-3 exhibited weak to modest correlations with ADAM10 on monocyte and DC subsets.

CONCLUSIONS

Our data indicated that ADAM10, especially its decreased expression on monocytes, may play an important role in the progression of CAD in KTRs. However, whether there is an interaction between ADAM10 and mTim-3 in the pathogenesis of CAD in KTRs needs to be further studied.

Combined Immune Checkpoint Blockade Enhances Antiviral Immunity against Bovine Leukemia Virus

Bovine leukemia virus (BLV) is a retrovirus that causes enzootic bovine leukosis (EBL) in cattle and is widespread in many countries, including Japan. Recent studies have revealed that the expression of immunoinhibitory molecules, such as programmed death-1 (PD-1) and PD-ligand 1, plays a critical role in immunosuppression and disease progression during BLV infection. In addition, a preliminary study has suggested that another immunoinhibitory molecule, T-cell immunoglobulin domain and mucin domain-3 (TIM-3), is involved in immunosuppression during BLV infection. Therefore, this study was designed to further elucidate the immunoinhibitory role of immune checkpoint molecules in BLV infection. TIM-3 expression was upregulated on peripheral CD4⁺ and CD8⁺ T cells in BLV-infected cattle. Interestingly, in EBL cattle, CD4⁺ and CD8⁺ T cells infiltrating lymphomas expressed TIM-3. TIM-3 and PD-1 were upregulated and coexpressed in peripheral CD4⁺ and CD8⁺ T cells from BLV-infected cattle. Blockade by anti-bovine TIM-3 monoclonal antibody increased CD69 expression on T cells and gamma interferon (IFN-γ) production from peripheral blood mononuclear cells from BLV-infected cattle. A syncytium formation assay also demonstrated the antiviral effects of TIM-3 blockade against BLV infection. The combined inhibition of TIM-3 and PD-1 pathways significantly enhanced IFN-γ production and antiviral efficacy compared to inhibition alone. In conclusion, the combined blockade of TIM-3 and PD-1 pathways shows strong immune activation and antiviral effects and has potential as a novel therapeutic method for BLV infection. IMPORTANCE Enzootic bovine leukosis caused by bovine leukemia virus (BLV) is an important viral disease in cattle, causing severe economic losses to the cattle industry worldwide. The molecular mechanisms of BLV-host interactions are complex. Previously, it was found that immune checkpoint molecules, such as PD-1, suppress BLV-specific Th1 responses as the disease progresses. To date, most studies have focused only on how PD-1 facilitates escape from host immunity in BLV-infected cattle and the antiviral effects of the PD-1 blockade. In contrast, how T-cell immunoglobulin domain and mucin domain-3 (TIM-3), another immune checkpoint molecule, regulates anti-BLV immune responses is rarely reported. It is also unclear why PD-1 inhibition alone was insufficient to exert anti-BLV effects in previous clinical studies. In this study, the expression profile of TIM-3 in T cells derived from BLV-infected cattle suggested that TIM-3 upregulation is a cause of immunosuppression in infected cattle. Based on these results, anti-TIM-3 antibody was used to experimentally evaluate its function in influencing immunity against BLV. Results indicated that TIM-3 upregulation induced by BLV infection suppressed T-cell activation and antiviral cytokine production. Some T cells coexpressed PD-1 and TIM-3, indicating that simultaneous inhibition of PD-1 and TIM-3 with their respective antibodies synergistically restored antiviral immunity. This study could open new avenues for treating bovine chronic infections.

Myeloid-derived suppressor cells in head and neck squamous cell carcinoma

Myeloid-derived suppressor cells (MDSCs), which originated from hematopoietic stem cells, are heterogeneous population of cells that have different differentiation patterns and widely presented in tumor microenvironment. For tumor research, myeloid suppressor cells have received extensive attention since their discovery due to their specific immunosuppressive properties, and the mechanisms of immunosuppression and therapeutic approaches for MDSCs have been investigated in a variety of different types of malignancies. To improve the efficacy of treatment for head and neck squamous cell carcinoma (HNSCC), a disease with a high occurrence, immunotherapy has gradually emerged in after traditional surgery and subsequent radiotherapy and chemotherapy, and has made some progress. In this review, we introduced the mechanisms on the development, differentiation, and elimination of MDSCs and provided a detailed overview of the mechanisms behind the immunosuppressive properties of MDSCs. We summarized the recent researches on MDSCs in HNSCC, especially for targeting-MDSCs therapy and combination with other types of therapy such as immune checkpoint blockade (ICB). Furthermore, we looked at drug delivery patterns and collected the current diverse drug delivery systems for the improvement that contributed to therapy against MDSCs in HNSCC. Most importantly, we made possible outlooks for the future research priorities, which provide a basis for further study on the clinical significance and therapeutic value of MDSCs in HNSCC.

Upregulation of Tim‐3 is associated with poor prognosis in acute myeloid leukemia

Acute myeloid leukemia (AML) is a heterogeneous hematopoietic malignancy originated from leukemia stem cells (LSC). Emerging evidence suggests T-cell immunoglobulin mucin-3(Tim3) as surface marker for LSC. However, the clinical significance and biology of Tim-3 in AML remain to be determined, especially those LSCs. In public AML databases as well as our data, we separated AML patients into Tim-3^high and Tim-3^low subsets using the X-tile software and evaluated the associations between Tim-3 and overall survival (OS) and disease-free survival (DFS). The Cancer Genome Atlas (TCGA) cohort revealed that high Tim-3 expression in leukemic cells was linked with poor prognosis (DFS: p = 0.018; OS: p = 0.041). Furthermore, multiple regression analysis shows that Tim-3 was an independent factor for the prognosis (HR = 2.26, 95% CI = 1.15-4.44, p = 0.017). Validation cohort of public gene expression omnibus (GEO) confirmed that Tim-3 was a prognostic candidate in AML. Besides, in our internal cohort, we also confirmed that over expression of Tim-3 protein in LSC/LPC made poor prognosis in AML. Additionally, we revealed that the LSC markers AKR1C3, CD34, and MMRN1 were upregulated in the Tim-3^high group of TCGA. We found that the upregulated genes in the Tim-3^high group were mainly enriched in immune response, cytokine binding and cell adhesion molecules, and JAK-STAT signaling pathway, by gene ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Collectively, we revealed that, for the first time, upregulation of Tim-3 in LSCs at the level of gene and protein expression is associated with poor prognosis and the important biological feature of Tim-3 of LSC in AML.

Plasma galectins and metabolites in advanced head and neck carcinomas: evidence of distinct immune characteristics linked to hypopharyngeal tumors

Extra-cellular galectins 1, 3 and 9 (gal-1, -3 and -9) are known to act as soluble immunosuppressive agents in various malignancies. Previous publications have suggested that their expression is dependent on the metabolic status of producing cells and reciprocally that they can influence metabolic pathways in their target cells. Very little is known about the status of gal-1, -3 and -9 in patients bearing head and neck squamous cell carcinomas (HNSCC) and about their relationships with the systemic metabolic condition. This study was conducted in plasma samples from a prospective cohort of 83 HNSCC patients with advanced disease. These samples were used to explore the distribution of gal-1, -3 and -9 and simultaneously to profile a series of 87 metabolites assessed by mass spectrometry. We identified galectin and metabolic patterns within five disease categories defined according to the primary site and human papillomavirus (HPV) status (HPV-positive and -negative oropharyngeal carcinomas, carcinomas of the oral cavity, hypopharynx and larynx carcinomas). Remarkably, samples related to hypopharyngeal carcinomas displayed the highest average concentration of gal-9 (p = .017) and a trend toward higher concentrations of kynurenine, a potential factor of tumor growth and immune suppression. In contrast, there was a tendency toward higher concentrations of fatty acids in samples related to oral cavity. These observations emphasize the diversity of HPV-negative HNSCCs. Depending on their primary site, they evolve into distinct types of immune and metabolic landscapes that seem to be congruent with specific oncogenic mechanisms.

In or out of control: Modulating regulatory T cell homeostasis and function with immune checkpoint pathways

Regulatory T cells (Tregs) are the master regulators of immunity and they have been implicated in different disease states such as infection, autoimmunity and cancer. Since their discovery, many studies have focused on understanding Treg development, differentiation, and function. While there are many players in the generation and function of truly suppressive Tregs, the role of checkpoint pathways in these processes have been studied extensively. In this paper, we systematically review the role of different checkpoint pathways in Treg homeostasis and function. We describe how co-stimulatory and co-inhibitory pathways modulate Treg homeostasis and function and highlight data from mouse and human studies. Multiple checkpoint pathways are being targeted in cancer and autoimmunity; therefore, we share insights from the clinic and discuss the effect of experimental and approved therapeutics on Treg biology.

Prevalence and prognostic significance of PD-L1, TIM-3 and B7-H3 expression in endometrial serous carcinoma

Endometrial serous carcinoma (ESC) is an aggressive type of endometrial carcinoma with a poor prognosis. Immune checkpoint blockade has evolved as a novel treatment option for endometrial cancers; however, data on expression of immune checkpoints that may be potential targets for immunotherapy in ESC are limited. We analyzed the prevalence and prognostic significance of PD-L1, TIM-3 and B7-H3 immune checkpoints in 99 ESC and evaluated their correlation with CD8 + tumor infiltrating lymphocytes. Applying the tumor proportion score (TPS) with a cutoff of 1%, PD-L1, TIM-3 and B7-H3 expression was present in 17%, 10% and 93% of cases, respectively. Applying the combined positive score (CPS) with a cutoff of 1, PD-L1, TIM-3 and B7-H3 expression was present in 63%, 67% and 94% of cases, respectively. Expression of these markers was largely independent of one another. PD-L1 correlated with higher CD8 + T-cell density when evaluated by either TPS (p = 0.02) or CPS (p < 0.0001). TIM-3 correlated with CD8 + T-cell density when evaluated by CPS (p < 0.0001). PD-L1 positivity was associated with improved overall survival (p = 0.038) when applying CPS. No association between PD-L1 expression and survival was found using TPS, and there was no association between TIM-3 or B7-H3 positivity and survival by either TPS or CPS. Using TPS, PD-L1 correlated with a higher tumor stage but not with survival, whereas the converse was true when PD-L1 was evaluated by CPS, suggesting that PD-L1 expression in immune cells correlates with prognosis and is independent of tumor stage. In conclusion, PD-L1, TIM-3 and B7-H3 may be potential therapeutic targets in selected patients with ESC. Further investigation of their roles as predictive biomarkers is needed.

Galectin-9/Tim-3 pathway mediates dopaminergic neurodegeneration in MPTP-induced mouse model of Parkinson’s disease

Galectin-9 (Gal-9) is a crucial immunoregulatory mediator in the central nervous system. Microglial activation and neuroinflammation play a key role in the degeneration of dopaminergic neurons in the substantia nigra (SN) in Parkinson’s disease (PD). However, it remains unknown whether Gal-9 is involved in the pathogenesis of PD. We found that MPP+ treatment promoted the expression of Gal-9 and pro-inflammatory cytokines (IL-6, IL-1β, TNF-α, and MIP-1α) in a concentration-dependent manner in BV2 cells. Gal-9 enhanced neurodegeneration and oxidative stress induced by MPP+ in SH-SY5Y cells and primary neurons. Importantly, deletion of Gal-9 or blockade of Tim-3 ameliorated microglial activation, reduced dopaminergic neuronal loss, and improved motor performance in an MPTP-induced mouse model of PD. These observations demonstrate a pathogenic role of the Gal-9/Tim-3 pathway in exacerbating microglial activation, neuroinflammation, oxidative stress, and dopaminergic neurodegeneration in the pathogenesis of PD.

Expression changes of Tim-3 as one of supplementary indicators for monitoring prognosis of liver pathological changes in chronic HBV infection

Purpose

This study was designed to analyze the liver tissue changes among the CHB patients who received treatment for at least 6 months and follow-up for at least 1 year, together with the correlation between the different disease condition and serum markers.

Methods

One-hundred and eighty-five CHB patients underwent antiviral therapy for at least 6 months were enrolled. In the 12-month follow-up, ultrasonography-guided biopsy was performed. The patients were grouped based on the serum markers and pathological changes in liver tissues. Then we determined the serum markers, virological tests and Tim-3 expression among these groups.

Results

Antiviral therapy significantly reduced liver inflammation indicators and serum Tim-3 level. However, the fibrosis process of liver tissue was not changed, and there are still disputes on the serum marker and hepatic lesion outcomes. Under normal liver function or negative hepatitis B e antigen (HBeAg) of CHB patients, there might be consensus between Tim-3 change and liver pathological outcome. According to the liver tissue inflammation and fibrosis conditions, Tim-3 was positively correlated with liver function indices. Besides, it was also related to fibrosis stage and inflammation grade.

Conclusion

There were inconsistent changes between serum markers and liver tissue conditions after anti-viral therapy. Tim-3 expression was more suitable to indicate the changes of liver inflammatory and fibrosis response to some extent than ALT and AST. It may serve as a certain indicator to predict the CHB prognosis, which could be used as one of the monitoring indicators in liver pathological changes of chronic HBV infection, especially in monitoring liver tissue inflammation.

Cutting edges and therapeutic opportunities on tumor-associated macrophages in lung cancer

Lung cancer is a disease with remarkable heterogeneity. A deep understanding of the tumor microenvironment (TME) offers potential therapeutic strategies against this malignant disease. More and more attention has been paid to the roles of macrophages in the TME. This article briefly summarizes the origin of macrophages, the mutual regulation between anti-tumoral immunity and pro-tumoral statuses derived from macrophage polarization, and the therapeutic opportunities targeting alternately activated macrophages (AAM)-type macrophage polarization. Among them, cellular components including T cells, as well as acellular components represented by IL-4 and IL-13 are key regulators driving the polarization of AAM macrophages. Novel treatments targeting macrophage-associated mechanisms are mainly divided into small molecule inhibitors, monoclonal antibodies, and other therapies to re-acclimate AMM macrophages. Finally, we paid special attention to an immunosuppressive subgroup of macrophages with T cell immunoglobulin and mucin domain-3 (TIM-3) expression. Based on cellular interactions with cancer cells, TIM3+ macrophages facilitate the proliferation and progression of cancer cells, yet this process exposes targets blocking the ligand-receptor recognition. To sum up, this is a systematic review on the mechanism of tumor-associated macrophages (TAM) polarization, therapeutic strategies and the biological functions of Tim-3 positive macrophages that aims to provide new insights into the pathogenesis and treatment of lung cancer.

Endocannabinoid signaling in microglia

Microglia, the innate immune cells of the central nervous system (CNS), execute their sentinel, housekeeping and defense functions through a panoply of genes, receptors and released cytokines, chemokines and neurotrophic factors. Moreover, microglia functions are closely linked to the constant communication with other cell types, among them neurons. Depending on the signaling pathway and type of stimuli involved, the outcome of microglia operation can be neuroprotective or neurodegenerative. Accordingly, microglia are increasingly becoming considered cellular targets for therapeutic intervention. Among signals controlling microglia activity, the endocannabinoid (EC) system has been shown to exert a neuroprotective role in many neurological diseases. Like neurons, microglia express functional EC receptors and can produce and degrade ECs. Interestingly, boosting EC signaling leads to an anti-inflammatory and neuroprotective microglia phenotype. Nonetheless, little evidence is available on the microglia-mediated therapeutic effects of EC compounds. This review focuses on the EC signals acting on the CNS microglia in physiological and pathological conditions, namely on the CB1R, CB2R and TRPV1-mediated regulation of microglia properties. It also provides new evidence, which strengthens the understanding of mechanisms underlying the control of microglia functions by ECs. Given the broad expression of the EC system in glial and neuronal cells, the resulting picture is the need for in vivo studies in transgenic mouse models to dissect the contribution of EC microglia signaling in the neuroprotective effects of EC-derived compounds.

Therapeutic Advances in Immunotherapies for Hematological Malignancies

Following the success of immunotherapies such as chimeric antigen receptor transgenic T-cell (CAR-T) therapy, bispecific T-cell engager therapy, and immune checkpoint inhibitors in the treatment of hematologic malignancies, further studies are underway to improve the efficacy of these immunotherapies and to reduce the complications associated with their use in combination with other immune checkpoint inhibitors and conventional chemotherapy. Studies of novel therapeutic strategies such as bispecific (tandem or dual) CAR-T, bispecific killer cell engager, trispecific killer cell engager, and dual affinity retargeting therapies are also underway. Because of these studies and the discovery of novel immunotherapeutic target molecules, the use of immunotherapy for diseases initially thought to be less promising to treat with this treatment method, such as acute myeloid leukemia and T-cell hematologic tumors, has become a reality. Thus, in this coming era of new transplantation- and chemotherapy-free treatment strategies, it is imperative for both scientists and clinicians to understand the molecular immunity of hematologic malignancies. In this review, we focus on the remarkable development of immunotherapies that could change the prognosis of hematologic diseases. We also review the molecular mechanisms, development processes, clinical efficacies, and problems of new agents.

Galectokines: The Promiscuous Relationship between Galectins and Cytokines

Galectins, a family of glycan-binding proteins, are well-known for their role in shaping the immune microenvironment. They can directly affect the activity and survival of different immune cell subtypes. Recent evidence suggests that galectins also indirectly affect the immune response by binding to members of another immunoregulatory protein family, i.e., cytokines. Such galectin-cytokine heterodimers, here referred to as galectokines, add a new layer of complexity to the regulation of immune homeostasis. Here, we summarize the current knowledge with regard to galectokine formation and function. We describe the known and potential mechanisms by which galectokines can help to shape the immune microenvironment. Finally, the outstanding questions and challenges for future research regarding the role of galectokines in immunomodulation are discussed.

Leishmania donovani Impedes Antileishmanial Immunity by Suppressing Dendritic Cells via the TIM-3 Receptor

An immunological hallmark of visceral leishmaniasis (VL), caused by Leishmania donovani, is profound immunosuppression. However, the molecular basis for this immune dysfunction has remained ill defined. Since dendritic cells (DCs) normally initiate antileishmanial immune responses, we investigated whether DCs are dysregulated during L. donovani infection and assessed its role in immunosuppression. Accordingly, we determined the regulatory effect of L. donovani on DCs. Notably, it is still unclear whether L. donovani activates or suppresses DCs. In addition, the molecular mechanism and the relevant receptor (or receptors) mediating the immunoregulatory effect of L. donovani on DCs are largely undefined. Here, we report that L. donovani inhibited DC activation/maturation by transmitting inhibitory signals through the T cell immunoglobulin and mucin protein-3 (TIM-3) receptor and thereby suppressed antileishmanial immune responses. L. donovani in fact triggered TIM-3 phosphorylation in DCs, which in turn recruited and activated a nonreceptor tyrosine kinase, Btk. Btk then inhibited DC activation/maturation by suppressing the NF-κB pathway in an interleukin-10 (IL-10)-dependent manner. Treatment with TIM-3-specific blocking antibody or suppressed expression of TIM-3 or downstream effector Btk made DCs resistant to the inhibitory effects of L. donovani. Adoptive transfer experiments further demonstrated that TIM-3-mediated L. donovani-induced inhibition of DCs plays a crucial role in the suppression of the antileishmanial immune response in vivo. These findings identify TIM-3 as a new regulator of the antileishmanial immune response and demonstrate a unique mechanism for host immunosuppression associated with L. donovani infection. IMPORTANCE Visceral leishmaniasis (VL), a poverty-related disease caused by Leishmania donovani, is ranked by the World Health Organization as the second largest killer parasitic disease in the world. The protective immune response against VL is primarily regulated by dendritic cells (DCs), which upon activation/maturation initiate an antileishmanial immune response. However, it remains obscure whether L. donovani promotes or inhibits DC activation. In addition, the receptor through which L. donovani exerts immunoregulatory effect on DCs is ill defined. Here, we for the first time report that L. donovani inhibits DC activation and maturation via the T cell immunoglobulin and mucin protein-3 (TIM-3) receptor and thereby attenuates the capacity of DCs to trigger antileishmanial immune responses in vivo. In fact, we demonstrate here that suppression of TIM-3 expression in DCs augments antileishmanial immunity. Our study uncovers a unique mechanism by which L. donovani subverts host immune responses and suggests TIM-3 as a potential new target for immunotherapy against VL.

The Fusion of Quantitative Molecular Proteomics and Immune-Oncology: A Step Towards Precision Medicine in Cancer Therapeutics

Innate and adaptive immune systems are built-in homeostatic functions of many multicellular organisms and protect the host against foreign pathogens and infections. Dysregulation of the molecular mechanisms of the immune system can result in autoimmune diseases. The immune system can also be harnessed and manipulated to provide targeted cancer therapies, some of them relying on the blockade of immune-checkpoint receptors. Two prominent immune checkpoints, PD-1/PD-L1 and CTLA-4/CD80, comprise receptor-ligand pairs that prevent the host immune cells from attacking host tissues. However, cancer cells upregulate the respective PD-L1 and CD80 ligands for PD-1 and CTLA-4 and thereby evade the host-immune response. Therapeutic drugs that block PD-1/PD-L1 and CTLA-4/CD80 interactions re-enable the immune system to attack cancer cells, but their prognostic biomarker remains challenging. In this review, we discuss how the use of quantitative molecular imaging can be exploited to predict the response to anti-PD-1/PD-L1 therapies and to identify cancer patients who would benefit from them.

Secreted filarial nematode galectins modulate host immune cells

Lymphatic filariasis (LF) is a mosquito-borne disease caused by filarial nematodes including Brugia malayi. Over 860 million people worldwide are infected or at risk of infection in 72 endemic countries. The absence of a protective vaccine means that current control strategies rely on mass drug administration programs that utilize inadequate drugs that cannot effectively kill adult parasites, thus established infections are incurable. Progress to address deficiencies in the approach to LF control is hindered by a poor mechanistic understanding of host-parasite interactions, including mechanisms of host immunomodulation by the parasite, a critical adaptation for establishing and maintaining infections. The canonical type 2 host response to helminth infection characterized by anti-inflammatory and regulatory immune phenotypes is modified by filarial nematodes during chronic LF. Current efforts at identifying parasite-derived factors driving this modification focus on parasite excretory-secretory products (ESP), including extracellular vesicles (EVs). We have previously profiled the cargo of B. malayi EVs and identified B. malayi galectin-1 and galectin-2 as among the most abundant EV proteins. In this study we further investigated the function of these proteins. Sequence analysis of the parasite galectins revealed highest homology to mammalian galectin-9 and functional characterization identified similar substrate affinities consistent with this designation. Immunological assays showed that Bma-LEC-2 is a bioactive protein that can polarize macrophages to an alternatively activated phenotype and selectively induce apoptosis in Th1 cells. Our data shows that an abundantly secreted parasite galectin is immunomodulatory and induces phenotypes consistent with the modified type 2 response characteristic of chronic LF infection.