Soluble TIM-3 as a biomarker of progression and therapeutic response in cancers and other of human diseases

Exploring immune checkpoint inhibitors: Focus on PD-1/PD-L1 axis and beyond

Immunotherapy emerges as a promising approach, marked by recent substantial progress in elucidating how the host immune response impacts tumor development and its sensitivity to various treatments. Immune checkpoint inhibitors have revolutionized cancer therapy by unleashing the power of the immune system to recognize and eradicate tumor cells. Among these, inhibitors targeting the programmed cell death protein 1 (PD-1) and its ligand (PD-L1) have garnered significant attention due to their remarkable clinical efficacy across various malignancies. This review delves into the mechanisms of action, clinical applications, and emerging therapeutic strategies surrounding PD-1/PD-L1 blockade. We explore the intricate interactions between PD-1/PD-L1 and other immune checkpoints, shedding light on combinatorial approaches to enhance treatment outcomes and overcome resistance mechanisms. Furthermore, we discuss the expanding landscape of immune checkpoint inhibitors beyond PD-1/PD-L1, including novel targets such as CTLA-4, LAG-3, TIM-3, and TIGIT. Through a comprehensive analysis of preclinical and clinical studies, we highlight the promise and challenges of immune checkpoint blockade in cancer immunotherapy, paving the way for future advancements in the field.

Serum soluble Tim‑3 is elevated in patients with cervical cancer and is higher in advanced clinical stages

T-cell immunoglobulin and mucin domain-containing protein-3 (Tim-3) is an immune checkpoint molecule that is expressed generally on the cell membrane of immune and cancer cells and is implicated as a negative regulator of anti-tumour immune responses; this occurs through the interaction of Tim-3 with galectin-9. Although the function of membrane Tim-3 is well known, the role of soluble Tim-3 (sTim-3) has been poorly explored. The aim of the present study was to compare the serum levels of sTim-3 in the cervical cancer group of patients vs. the control group, to determine the association between the serum levels of sTim-3 with the clinicopathological characteristics of patients with cervical cancer and with serum galectin-9 levels. The concentrations of serum sTim-3 and galectin-9 were determined using ELISA. A receiver operating characteristic (ROC) curve was performed to determine the diagnostic value of sTim-3. The Mann-Whitney and Kruskall-Wallis tests were used to compare the serum sTim-3 concentrations between the control and cervical cancer groups and among the clinical subgroups. The association between the concentrations of sTim-3 and galectin-9 was determined using Spearman's rank correlation coefficient. sTim-3 expression was higher in patients with cervical cancer compared with control patients. The ROC curve revealed that sTim-3 has diagnostic potential, with a specificity of 95% and a sensitivity of 85.19%. sTim-3 was higher in patients with International Federation of Gynaecology and Obstetrics (FIGO) stage IV compared with those with FIGO stages I, II and III. A moderate positive correlation (ρ=0.41) was identified between sTim-3 and galectin-9. This was the first report of changes in the serum concentrations of sTim-3 in patients with cervical cancer and their diagnostic value. The association between sTim-3 with cervical cancer progression, and the positive correlation between the serum concentrations of sTim-3 and galectin-9 suggested that both proteins might be involved in the immune dysregulation in cervical cancer, but this requires further exploration.

Characterization of alternative sPD-1 isoforms reveals that ECD sPD-1 signature predicts an efficient antitumor response

Soluble PD-1 is a dissociated form of membrane PD-1 broadly present in cancer, infections, or autoimmune diseases. However, the clinical significance of sPD-1 remains controversial due to the uncertainty of its isoforms, origin, and production mechanism. Here, using antibodies specifically binding to the intracellular domain of PD-1, we identified two sPD-1 isoforms in cancers at the protein level: FL sPD-1 containing both the extra- and intracellular domains of PD-1, and ECD sPD-1 containing only the extracellular fragment. Subsequently, we tracked their origin and found that in tumor models, both sPD-1 isoforms were generated by activated CD8 T cells highly expressing membrane PD-1. However, ECD sPD-1 was released from live PD-1+T cells by matrix metalloproteinases, while FL sPD-1 production was accompanied by PD-1+T cell death. Therefore, only ECD sPD-1 predicts effective immune response and better tumor outcome. Our study distinguished sPD-1 isoforms and highlighted ECD sPD-1 as a prognostic biomarker in cancer.

Soluble Immune Checkpoint Protein and Lipid Network Associations with All-Cause Mortality Risk: Trans-Omics for Precision Medicine (TOPMed) Program

Adverse cardiovascular events are emerging with the use of immune checkpoint therapies in oncology. Using datasets in the Trans-Omics for Precision Medicine program (Multi-Ethnic Study of Atherosclerosis, Jackson Heart Study [JHS], and Framingham Heart Study), we examined the association of immune checkpoint plasma proteins with each other, their associated protein network with high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C), and the association of HDL-C- and LDL-C-associated protein networks with all-cause mortality risk. Plasma levels of LAG3 and HAVCR2 showed statistically significant associations with mortality risk. Colocalization analysis using genome wide-association studies of HDL-C or LDL-C and protein quantitative trait loci from JHS and the Atherosclerosis Risk in Communities identified TFF3 rs60467699 and CD36 rs3211938 variants as significantly colocalized with HDL-C; in contrast, none colocalized with LDL-C. The measurement of plasma LAG3, HAVCR2, and associated proteins plus targeted genotyping may identify patients at increased mortality risk.

RECQL4 affects MHC class II-mediated signalling and favours an immune-evasive signature that limits response to immune checkpoint inhibitor therapy in patients with malignant melanoma

BACKGROUND

Cancer immunotherapy has transformed metastatic cancer treatment, yet challenges persist regarding therapeutic efficacy. RECQL4, a RecQ-like helicase, plays a central role in DNA replication and repair as part of the DNA damage response, a pathway implicated in enhancing efficacy of immune checkpoint inhibitor (ICI) therapies. However, its role in patient response to ICI remains unclear.

METHODS

We analysed whole exome and bulk RNA sequencing data from a pan-cancer cohort of 25 775 patients and cutaneous melanoma cohorts (untreated: n = 471, anti-progressive disease [PD]-1 treated: n = 212). RECQL4 copy number variations and expression levels were assessed for patient outcomes. We performed gene set enrichment analysis to identify RECQL4-dependent signalling pathways and explored the association between RECQL4 levels and immunoscores. We evaluated the interplay of ICI response and RECQL4 expression in melanoma cohorts of 95 responders and 85 non-responders prior to and after ICI-targeted therapy and tested the prognostic power of RECQL4. Finally, we generated genetically engineered RECQL4 variants and conducted comprehensive multi-omic profiling, employing techniques such as liquid chromatography with tandem mass spectrometry, to elucidate mechanistic insights.

RESULTS

We identified RECQL4 as a critical negative regulator of poor prognosis and response to ICI therapy, but also demonstrated its suitability as an independent biomarker in melanoma. High tumour purity and limited signatures of tumour immunogenicity associated with response to anti-PD-1 correlated with high RECQL4 activity. We found alterations in the secretion profile of immune regulatory factors and immune-related pathways robustly suppressed in tumours with high RECQL4 levels, underscoring its crucial role in fostering immune evasion. Mechanistically, we identified RECQL4-mediated regulation of major histocompatibility complex class II molecule expression and uncovered class II major histocompatibility complex transactivator as a mediator bridging this regulation.

CONCLUSIONS

Our findings unraveled the pivotal role of RECQL4 in immune modulation and its potential as both a predictive biomarker and therapeutic target for optimising immunotherapeutic strategies across various cancer types.

HIGHLIGHTS

High RECQL4 expression limits survival and can act as an independent prognostic factor in melanoma patients. RECQL4 has the potential to act as a negative feedback mediator of immune checkpoint-targeted therapy by limiting signatures associated with therapeutic efficacy. RECQL4 favours an immune-evasive phenotype by downregulating major histocompatibility complex class II molecules.

The expression of immune response genes in patients with chronic Chagas disease is shifted toward the levels observed in healthy subjects as a result of treatment with Benznidazole

Introduction

Chagas disease, caused by the Trypanosoma cruzi parasite infection, is a potentially life-threatening neglected tropical disease with a worldwide distribution. During the chronic phase of the disease, there exists a fragile balance between the host immune response and parasite replication that keeps patients in a clinically-silent asymptomatic stage for years or even decades. However, in 40% of patients, the disease progresses to clinical manifestations mainly affecting and compromising the cardiac system. Treatment is recommended in the chronic phase, although there are no early markers of its effectiveness. The aim of this study is to identify differential expression changes in genes involved in the immune response in antigen-restimulated PBMC from chronic patients with Chagas disease due to benznidazole treatment.

Methods

Thus, high-throughput real-time qPCR analysis has been performed to simultaneously determine global changes in the expression of 106 genes involved in the immune response in asymptomatic (IND) and early cardiac manifestations (CCC I) Chagas disease patients pre- and post-treatment with benznidazole.

Results and discussion

The results revealed that 7 out of the 106 analyzed genes were differentially expressed (4 up- and 3 downregulated) after treatment in IND patients and 15 out of 106 (3 up- and 12 downregulated) after treatment of early cardiac Chagas disease patients. Particularly in CCC I patients, regulation of the expression level of some of these genes towards a level similar to that of healthy subjects suggests a beneficial effect of treatment and supports recommendation of benznidazole administration to early cardiac Chagas disease patients. The data obtained also demonstrated that both in asymptomatic patients and in early cardiac chronic patients, after treatment with benznidazole there is a negative regulation of the proinflammatory and cytotoxic responses triggered as a consequence of T. cruzi infection and the persistence of the parasite. This downregulation of the immune response likely prevents marked tissue damage and healing in early cardiac patients, suggesting its positive effect in controlling the pathology.

Soluble form of immune checkpoints in autoimmune diseases

Immune checkpoints are essential regulators of immune responses, either by activating or suppressing them. Consequently, they are regarded as pivotal elements in the management of infections, cancer, and autoimmune disorders. In recent years, researchers have identified numerous soluble immune checkpoints that are produced through various mechanisms and demonstrated biological activity. These soluble immune checkpoints can be produced and distributed in the bloodstream and various tissues, with their roles in immune response dysregulation and autoimmunity extensively documented. This review aims to provide a thorough overview of the generation of various soluble immune checkpoints, such as sPD-1, sCTLA-4, sTim-3, s4-1BB, sBTLA, sLAG-3, sCD200, and the B7 family, and their importance as indicators for the diagnosis and prediction of autoimmune conditions. Furthermore, the review will investigate the potential pathological mechanisms of soluble immune checkpoints in autoimmune diseases, emphasizing their association with autoimmune diseases development, prognosis, and treatment.

Evaluation of soluble co-inhibitors and co-stimulators levels of the immune response in gastric cancer

BACKGROUND

Co-inhibitor and co-stimulator mediators trigger actions that result in immunological homeostasis and are being evaluated as potential therapeutic targets in gastric cancer (GC).

OBJECTIVE

To evaluate the soluble levels of sPD-1, sPD-L1, sPD-L2, sTIM-3, sGal9, sGITR, and sGITRL in GC patients.

METHODS

The cross-sectional study was carried out at the Hospital de Cancer de Pernambuco, Brazil between 2017 and 2018. A total of 74 GC patients and 30 healthy controls were included.

RESULTS

Low levels of sPD1 (p = 0.0179), sPDL2 (p = 0.0003), and sGal9 (p < 0.0001), and higher levels of sPDL1 (p = 0.004), sTIM-3 (p = 0.0072), sGITR (p = 0.0179), and sGITRL (p = 0.0055) compared to the control group. High sPD-1, sTIM-3, and sGal9 levels in stage IV compared I/II and III (p < 0.05). High sPDL1, sGal9, and sGITRL levels in esophagogastric junction compared to body and Pylorus/Antrum groups (p < 0.05). No significant differences were observed in sPD1, sPDL1, sPDL2, sTIM3, sGal9, sGITR, and sGITRL levels between the intestinal, diffuse, and mixed GC groups. Low sGITR levels in GC patients who died within the first 24 months compared to the who survived (p = 0.0332).

CONCLUSIONS

There is an association of sPD1, sTIM-3, and sGal9 with disease progression and sGITR with death, these mediators may be potential prognostic biomarkers in GC.

Monitoring the Immune System in Critically Ill Patients (Review)

Most patients with critical illness, regardless of the cause, develop activation of innate and adaptive immunity. This is often a critical process leading to organ dysfunction.

The aim of the review is to systematize information on monitoring the immune system in critical illness for physicians of different specialties (anesthesiology and intensive care, surgery, general practice, obstetrics and gynecology).

The review includes information from 83 recent national and international publications (mostly from 2023), available in the public domain and found by keyword search.

We have summarized the current understanding of the relationship between infections and the human immune system, as well as the clinical application of traditional markers of immune status. We provided data on novel promising markers for the assessment of immunity in patients with various diseases.

Limitations of the studies reviewed include the need for additional large-scale clinical trials of even the most promising markers, as well as a synthesis of the evidence for their performance. In addition, immune monitoring is likely to increase the cost of patient care, necessitating the development of more affordable research methods.

Conclusion. Almost all disorders in critically ill patients are associated with changes in the immune system. Management of patients based on their immune profile requires determination of a personalized strategy for immune modulation, treatment, and prevention of infection. Advanced monitoring of immune system functions will contribute to the personalization of medicine, and the continuous development of biological technologies will allow to improve its methods.

To develop a prognostic model for neoadjuvant immunochemotherapy efficacy in esophageal squamous cell carcinoma by analyzing the immune microenvironment

Objective

The choice of neoadjuvant therapy for esophageal squamous cell carcinoma (ESCC) is controversial. This study aims to provide a basis for clinical treatment selection by establishing a predictive model for the efficacy of neoadjuvant immunochemotherapy (NICT).

Methods

A retrospective analysis of 30 patients was conducted, divided into Response and Non-response groups based on whether they achieved major pathological remission (MPR). Differences in genes and immune microenvironment between the two groups were analyzed through next-generation sequencing (NGS) and multiplex immunofluorescence (mIF). Variables most closely related to therapeutic efficacy were selected through LASSO regression and ROC curves to establish a predictive model. An additional 48 patients were prospectively collected as a validation set to verify the model's effectiveness.

Results

NGS suggested seven differential genes (ATM, ATR, BIVM-ERCC5, MAP3K1, PRG, RBM10, and TSHR) between the two groups (P < 0.05). mIF indicated significant differences in the quantity and location of CD3+, PD-L1+, CD3+PD-L1+, CD4+PD-1+, CD4+LAG-3+, CD8+LAG-3+, LAG-3+ between the two groups before treatment (P < 0.05). Dynamic mIF analysis also indicated that CD3+, CD8+, and CD20+ all increased after treatment in both groups, with a more significant increase in CD8+ and CD20+ in the Response group (P < 0.05), and a more significant decrease in PD-L1+ (P < 0.05). The three variables most closely related to therapeutic efficacy were selected through LASSO regression and ROC curves: Tumor area PD-L1+ (AUC= 0.881), CD3+PD-L1+ (AUC= 0.833), and CD3+ (AUC= 0.826), and a predictive model was established. The model showed high performance in both the training set (AUC= 0.938) and the validation set (AUC= 0.832). Compared to the traditional CPS scoring criteria, the model showed significant improvements in accuracy (83.3% vs 70.8%), sensitivity (0.625 vs 0.312), and specificity (0.937 vs 0.906).

Conclusion

NICT treatment may exert anti-tumor effects by enriching immune cells and activating exhausted T cells. Tumor area CD3+, PD-L1+, and CD3+PD-L1+ are closely related to therapeutic efficacy. The model containing these three variables can accurately predict treatment outcomes, providing a reliable basis for the selection of neoadjuvant treatment plans.

Interaction of the Immune System TIM-3 Protein with a Model Cellular Membrane Containing Phosphatidyl-Serine Lipids

T cell transmembrane, Immunoglobulin, and Mucin (TIM) are important immune system proteins which are especially present in T-cells and regulated the immune system by sensing cell engulfment and apoptotic processes. Their role is exerted by the capacity to detect the presence of phosphatidyl-serine lipid polar head in the outer leaflet of cellular membranes (correlated with apoptosis). In this contribution by using equilibrium and enhanced sampling molecular dynamics simulation we unravel the molecular bases and the thermodynamics of TIM, and in particular TIM-3, interaction with phosphatidyl serine in a lipid bilayer. Since TIM-3 deregulation is an important factor of pro-oncogenic tumor micro-environment understanding its functioning at a molecular level may pave the way to the development of original immunotherapeutic approaches.

Post-transplant Inflammatory Bowel Disease Associated with Donor-Derived TIM-3 Deficiency

Inflammatory bowel disease (IBD) occurring following allogeneic stem cell transplantation (aSCT) is a very rare condition. The underlying pathogenesis needs to be better defined. There is currently no systematic effort to exclude loss- or gain-of-function mutations in immune-related genes in stem cell donors. This is despite the fact that more than 100 inborn errors of immunity may cause or contribute to IBD. We have molecularly characterized a patient who developed fulminant inflammatory bowel disease following aSCT with stable 100% donor-derived hematopoiesis. A pathogenic c.A291G; p.I97M HAVCR2 mutation encoding the immune checkpoint protein TIM-3 was identified in the patient's blood-derived DNA, while being absent in DNA derived from the skin. TIM-3 expression was much decreased in the patient's serum, and in vitro-activated patient-derived T cells expressed reduced TIM-3 levels. In contrast, T cell-intrinsic CD25 expression and production of inflammatory cytokines were preserved. TIM-3 expression was barely detectable in the immune cells of the patient's intestinal mucosa, while being detected unambiguously in the inflamed and non-inflamed colon from unrelated individuals. In conclusion, we report the first case of acquired, "transplanted" insufficiency of the regulatory TIM-3 checkpoint linked to post-aSCT IBD.

Intratumoral delivery of a Tim-3 antibody-encoding oncolytic adenovirus engages an effective antitumor immune response in liver cancer

BACKGROUND AND PURPOSE

The use of oncolytic viruses as a gene therapy vector is an area of active biomedical research, particularly in the context of cancer treatment. However, the actual therapeutic success of this approach to tumor elimination remains limited. As such, the present study was developed with the goal of simultaneously enhancing the antitumor efficacy of oncolytic viruses and the local immune response by combining the Ad-GD55 oncolytic adenovirus and an antibody specific for the TIM-3 immune checkpoint molecule (α-TIM-3).

APPROACH AND KEY RESULTS

The results of Virus and cell-mediated cytotoxicity assay, qPCR, and Western immunoblotting showed that Ad-GD55-α-Tim-3 oncolytic adenovirus is capable of inducing α-TIM-3 expression within hepatoma cells upon infection, and Ad-GD55-α-TIM-3 exhibited inhibitory efficacy superior to that of Ad-GD55 when used to treat these tumor cells together with the induction of enhanced intracellular immunity. In vivo experiments revealed that Ad-GD55-α-TIM-3 administration was sufficient to inhibit tumor growth and engage in a more robust local immune response within the simulated tumor immune microenvironment.

CONCLUSION AND IMPLICATIONS

These results highlighted the promising therapeutic effects of Ad-GD55-α-TIM-3 oncolytic adenovirus against HCC in vitro and in vivo. As such, this Ad-GD55-α-TIM-3 oncolytic adenovirus may represent a viable approach to the treatment of hepatocellular carcinoma.

Cancer cell-intrinsic PD-1: Its role in malignant progression and immunotherapy

Programmed cell death protein-1 (PD-1), also called CD279, is coded by the PDCD1 gene and is constitutively expressed on the surface of immune cells. As a receptor and immune checkpoint, PD-1 can bind to programmed death ligand-1/programmed death ligand-2 (PD-L1/PD-L2) in tumor cells, leading to tumor immune evasion. Anti-PD-1 and anti-PD-L1 are important components in tumor immune therapy. PD-1 is also expressed as an intrinsic variant (iPD-1) in cancer cells where it plays important roles in malignant progression as proposed by recent studies. However, iPD-1 has received much less attention compared to PD-1 expressed on immune cells although there is an unmet medical need for fully elucidating the mechanisms of actions to achieve the best response in tumor immunotherapy. iPD-1 suppresses tumorigenesis in non-small cell lung cancer (NSCLC) and colon cancer, whereas it promotes tumorigenesis in melanoma, hepatocellular carcinoma (HCC), pancreatic ductal adenocarcinoma (PDAC), thyroid cancer (TC), glioblastoma (GBM), and triple-negative breast cancer (TNBC). In this review, we focus on the role of iPD-1 in tumorigenesis and development and its molecular mechanisms. We also deeply discuss nivolumab-based combined therapy in common tumor therapy. iPD-1 may explain the different therapeutic effects of anti-PD-1 treatment and provide critical information for use in combined anti-tumor approaches.

N-glycosylation reinforces interaction of immune checkpoint TIM-3 with a small molecule ligand

N-glycosylation of eukaryotic proteins plays roles in protein folding, trafficking, and signal transduction. The biological influence of the process is well understood, whereas the pharmacological impact of protein N-glycosylation is not well under discerned. The role of N-glycosylation on drug binding to protein has been rarely studied. We have modeled the influence of a bi-antennary N-glycan introduced at position N78 on the immune checkpoint TIM-3 (T cell immunoglobulin domain and mucin domain-containing molecule 3) on the interaction with a selective drug antagonist. The bulky N-glycan introduced at the consensus sequence Asn-Val-Thr has no influence on drug binding when the glycan adopts an extended conformation. But in a folded conformation, the glycan can interact directly with the triazoloquinazolinone derivative so as to further stabilize the drug-TIM-3 complex. The non-fucosylated glycan at position N78 markedly consolidates the drug interaction, via an additional H-bond interaction with the α3-mannose residue. It provides a gain of empirical potential energy of interaction (ΔE) of about 30 %. The presence of a more rigid fucosylated N-glycan is a little less favorable, with a gain of ΔE of about 20 %. The folded N-glycan appears to protect the ligand bound to the protein cavity, with the tricyclic core of the heterocyclic molecule sandwiched between two indole rings of tryptophan residues. Similar results were obtained when using a biantennary disialyl N-glycan with a bisecting GlcNAc residue and a tetra-antennary N-glycan. The molecular models illustrate the drug-stabilizing capacity of a bulky N-glycan positioned at a validated glycosylation site (N78 corresponding to N100 for the full-length protein). The modeling approach is useful to delineate further the role of the N-glycan of the immune checkpoint TIM-3 in interaction with small molecule ligands, and to guide the design of more potent compounds. The approach is transposable to other proteins to better comprehend the influence of N-glycans on drug-receptor interactions.