Soluble LAG3 acts as a potential prognostic marker of gastric cancer and its positive correlation with CD8+T cell frequency and secretion of IL-12 and INF-γ in peripheral blood

Advances in LAG3 cancer immunotherapeutics

Cancer treatment has entered the age of immunotherapy. Immune checkpoint inhibitor (ICI) therapy has shown robust therapeutic potential in clinical practice, with significant improvements in progression-free survival (PFS) and overall survival (OS). Recently, checkpoint blockade of the lymphocyte activation gene 3 (LAG3) inhibitory receptor (IR) in combination with programmed death protein 1 (PD1) inhibition has been FDA approved in patients with advanced melanoma. This has encouraged the clinical evaluation of new LAG3-directed biologics in combination with other checkpoint inhibitors. Several of these studies are evaluating bispecific antibodies that target exhausted T (TEX) cells expressing multiple IRs. This review discusses the current understanding of LAG3 in regulating antitumor immunity and the ongoing clinical testing of LAG3 inhibition in cancer.

The Role of YY1 in the Regulation of LAG-3 Expression in CD8 T Cells and Immune Evasion in Cancer: Therapeutic Implications

The treatment of cancers with immunotherapies has yielded significant milestones in recent years. Amongst these immunotherapeutic strategies, the FDA has approved several checkpoint inhibitors (CPIs), primarily Anti-Programmed Death-1 (PD-1) and Programmed Death Ligand-1/2 (PDL-1/2) monoclonal antibodies, in the treatment of various cancers unresponsive to immune therapeutics. Such treatments resulted in significant clinical responses and the prolongation of survival in a subset of patients. However, not all patients responded to CPIs, due to various mechanisms of immune resistance. One such mechanism is that, in addition to PD-1 expression on CD8 T cells, other inhibitory receptors exist, such as Lymphocyte Activation Gene 3 (LAG-3), T cell Immunoglobulin Mucin 3 (TIM3), and T cell immunoreceptor with Ig and ITIM domains (TIGIT). These inhibitory receptors might be active in the presence of the above approved CPIs. Clearly, it is clinically challenging to block all such inhibitory receptors simultaneously using conventional antibodies. To circumvent this difficulty, we sought to target a potential transcription factor that may be involved in the molecular regulation of more than one inhibitory receptor. The transcription factor Yin Yang1 (YY1) was found to regulate the expression of PD-1, LAG-3, and TIM3. Therefore, we hypothesized that targeting YY1 in CD8 T cells should inhibit the expression of these receptors and, thus, prevent the inactivation of the anti-tumor CD8 T cells by these receptors, by corresponding ligands to tumor cells. This strategy should result in the prevention of immune evasion, leading to the inhibition of tumor growth. In addition, this strategy will be particularly effective in a subset of cancer patients who were unresponsive to approved CPIs. In this review, we discuss the regulation of LAG-3 by YY1 as proof of principle for the potential use of targeting YY1 as an alternative therapeutic approach to preventing the immune evasion of cancer. We present findings on the molecular regulations of both YY1 and LAG-3 expressions, the direct regulation of LAG-3 by YY1, the various approaches to targeting YY1 to evade immune evasion, and their clinical challenges. We also present bioinformatic analyses demonstrating the overexpression of LAG-3, YY1, and PD-L1 in various cancers, their associations with immune infiltrates, and the fact that when LAG-3 is hypermethylated in its promoter region it correlates with a better overall survival. Hence, targeting YY1 in CD8 T cells will result in restoring the anti-tumor immune response and tumor regression. Notably, in addition to the beneficial effects of targeting YY1 in CD8 T cells to inhibit the expression of inhibitory receptors, we also suggest targeting YY1 overexpressed in the tumor cells, which will also inhibit PD-L1 expression and other YY1-associated pro-tumorigenic activities.

Lymphocyte-activation gene 3 in cancer immunotherapy: function, prognostic biomarker and therapeutic potentials

Lymphocyte-activation gene 3 (LAG-3) has emerged as a key immune checkpoint regulating immune responses in the context of cancer. The inhibitory effect of LAG-3-expressing T cells contributes to suppressing anti-tumor immunity and promoting tumor progression. This review discusses the function of LAG-3 in immune suppression, its interactions with ligands, and its potential as a prognostic biomarker for cancers. We also explore therapeutic strategies targeting LAG-3, including monoclonal antibodies, small molecule inhibitors, and CAR T cells. This review summarizes the current preclinical and clinical studies on LAG-3, highlighting the potential of therapeutic regimens targeting LAG-3 to enhance antitumor immunity and improve patients' outcomes. Further studies are needed to fully elucidate the mechanism of action of LAG-3 and optimize its application in tumor therapy.

Deciphering LAG-3: unveiling molecular mechanisms and clinical advancements

Treatment based on immune checkpoint blockade has revolutionized cancer therapy. Despite the remarkable success achieved and the preclinical development of multiple checkpoint inhibitors targeting other checkpoints, only antibodies targeting the PD-1/PD-L1 axis and CTLA-4 have been approved for patient treatment, especially in solid tumors. Currently, with the approval of relatlimab, a LAG-3 blocking antibody, a third player, has been used in the fight against cancer. The endorsement of relatlimab marks a significant milestone in cancer immunotherapy, opening new avenues for combination therapies and enhancing treatment outcomes. However, the complex biology of LAG-3 may hinder its full development as a therapeutic alternative. In this review, we provide in-depth insight into the biology of LAG-3 and its current and future development in cancer treatment.

Advances in understanding the role of immune checkpoint LAG-3 in tumor immunity: a comprehensive review

Lymphocyte activation gene 3 (LAG-3), also known as CD223, is an emerging immune checkpoint that follows PD-1 and CTLA-4. Several LAG-3 targeting inhibitors in clinical trials and the combination of relatlimab (anti-LAG-3) and nivolumab (anti-PD-1) have been approved for treating - unresectable or metastatic melanoma. Despite the encouraging clinical potential of LAG-3, the physiological function and mechanism of action in tumors are still not well understood. In this review, we systematically summarized the structure of LAG-3, ligands of LAG-3, cell-specific functions and signaling of LAG-3, and the current status of LAG-3 inhibitors under development.

Effects of HOX family regulator-mediated modification patterns and immunity characteristics on tumor-associated cell type in endometrial cancer

Endometrial cancer (UCEC) is one of three major malignant tumors in women. The HOX gene regulates tumor development. However, the potential roles of HOX in the expression mechanism of multiple cell types and in the development and progression of tumor microenvironment (TME) cell infiltration in UCEC remain unknown. In this study, we utilized both the The Cancer Genome Atlas (TCGA) database and International Cancer Genome Consortium (ICGC) database to analyze transcriptome data of 529 patients with UCEC based on 39 HOX genes, combing clinical information, we discovered HOX gene were a pivotal factor in the development and progression of UCEC and in the formation of TME diversity and complexity. Here, a new scoring system was developed to quantify individual HOX patterns in UCEC. Our study found that patients in the low HOX score group had abundant anti-tumor immune cell infiltration, good tumor differentiation, and better prognoses. In contrast, a high HOX score was associated with blockade of immune checkpoints, which enhances the response to immunotherapy. The Real-Time quantitative PCR (RT-qPCR) and Immunohistochemistry (IHC) exhibited a higher expression of the HOX gene in the tumor patients. We revealed that the significant upregulation of the HOX gene in the epithelial cells can activate signaling pathway associated with tumour invasion and metastasis through single-cell RNA sequencing (scRNA-seq), such as nucleotide metabolic proce and so on. Finally, a risk prognostic model established by the positive relationship between HOX scores and cancer-associated fibroblasts (CAFs) can predict the prognosis of individual patients by scRNA-seq and transcriptome data sets. In sum, HOX gene may serve as a potential biomarker for the diagnosis and prediction of UCEC and to develop more effective therapeutic strategies.

Soluble immune checkpoints: implications for cancer prognosis and response to immune checkpoint therapy and conventional therapies

Longitudinal sampling of tumor tissue from patients with solid cancers, aside from melanoma and a few other cases, is often unfeasible, and thus may not capture the plasticity of interactions between the tumor and immune system under selective pressure of a given therapy. Peripheral blood analyses provide salient information about the human peripheral immunome while offering technical and practical advantages over traditional tumor biopsies, and should be utilized where possible alongside interrogation of the tumor. Some common blood-based biomarkers used to study the immune response include immune cell subsets, circulating tumor DNA, and protein analytes such as cytokines. With the recent explosion of immune checkpoint inhibitors (ICI) as a modality of treatment in multiple cancer types, soluble immune checkpoints have become a relevant area of investigation for peripheral immune-based biomarkers. However, the exact functions of soluble immune checkpoints and their roles in cancer for the most part remain unclear. This review discusses current literature on the production, function, and expression of nine soluble immune checkpoints - sPD-L1, sPD-1, sCTLA4, sCD80, sTIM3, sLAG3, sB7-H3, sBTLA, and sHVEM - in patients with solid tumors, and explores their role as biomarkers of response to ICI as well as to conventional therapies (chemotherapy, radiotherapy, targeted therapy, and surgery) in cancer patients.

Implications of LAG3 and CTLA4 immune checkpoints beyond PD-1/PD-L1 as a potential target in determining the prognosis of uveal melanoma patients

BackgroundResponse rate of PD-1/PD-L1 immunotherapeutic blockade agents in uveal melanoma (UM) is poor. Lymphocyte activation gene 3 (LAG3) and cytotoxic T-lymphocyte-associated protein 4 (CTLA4) are the two promising immune checkpoint targets. Therefore, our aim was to explore at how these proteins were expressed in tumour tissue and serum, as well as their prognostic implications in UM.

METHODS

The expression of LAG3, CTLA-4, CD3, CD4, CD8 and FOXP3 was determined by immunohistochemistry in 54 enucleated UM tissue samples. mRNA expression level of LAG3 and CTLA-4 was determined by quantitative real-time PCR and corroborated by western blotting. Furthermore, soluble form of LAG3, CTLA-4 and CCR8 expression in serum was measured in 40 UM patients using ELISA.

RESULT

The expression of LAG3, CTLA-4, CD3, CD4, CD8 and FOXP3 was observed in 30%, 33%, 41%, 35%, 50% and 39% of the cases, respectively. Loss of nBAP1 expression was significantly correlated with CD8+expression (p=0.012) but not with tumour infiltrating lymphocytes. LAG3 and CTLA-4 mRNA levels were higher in UM compared with normal uveal tissues. Higher LAG3 expression with CD8+expression was associated with lower metastasis-free survival (MFS) (p=0.049), but not with CTLA-4 in UM patients. MFS rate was reduced in patients having lower levels of CCR8 protein (p=0.050) and increased level of LAG3 protein (p=0.001).

CONCLUSION

Our findings suggest that higher levels of LAG3 in UM with histopathologically high-risk parameters predict high metastatic potential and that it could be used as a targeted immunotherapy alone or in combination with PD-1/PD-L1 blockade agents.

Overcoming Lot-to-Lot Variability in Protein Activity Using Epitope-Specific Calibration-Free Concentration Analysis

Concentration determination is a fundamental hallmark of protein reagent characterization, providing a means to ensure reproducibility and unify measurements from various assays. However, lot-to-lot differences in protein activity often still occur, leading to uncertainty in the accuracy of downstream measurements. Here, we postulate that those differences are caused by a misrepresentation of the protein concentration as measured by traditional total protein techniques, which can include multiple types of inactive protein species. To overcome this, we developed a standardized method to quantify a protein's active concentration via calibration-free concentration analysis (CFCA). As a pilot study, we compare the biophysical and immunoassay responses from three batches of recombinant soluble lymphocyte-activation gene 3 (sLAG3), as defined by either their total or active concentrations. Defining the sLAG3 reagents by their assay-specific concentration improved consistency in reported kinetic binding parameters and decreased immunoassay lot-to-lot coefficients of variation (CVs) by over 600% compared to the total protein concentration. These findings suggest that the total concentration of a protein reagent may not be the ideal metric to correlate in-assay signals between lots, and by instead quantifying the concentrations of a reagent's assay-specific epitopes, CFCA may prove a useful tool in overcoming lot-to-lot variability.

Soluble lymphocyte activation gene-3 (sLAG3) and CD4/CD8 ratio dynamics as predictive biomarkers in patients undergoing immune checkpoint blockade for solid malignancies

BACKGROUND

The search for biomarkers to identify suitable candidates for immune checkpoint inhibitor (ICI) therapy remains ongoing. We evaluate how soluble levels of the next generation immune checkpoint Lymphocyte Activation Gene-3 (sLAG-3) and its association with circulating T lymphocyte subsets could pose as a novel biomarker to predict outcome to ICI therapy.

METHODS

Circulating levels of sLAG3 were analyzed using multiplex immunoassay in n = 84 patients undergoing ICI therapy for advanced solid cancer, accompanied by flow cytometry analyses of peripheral blood mononuclear cells (PBMCs).

RESULTS

Uni- and multivariate analysis shows that patients with higher sLAG3 concentrations before ICI therapy had a significantly impaired progression-free (PFS) and overall survival (OS) (HRPFS: 1.005 [95%CI: 1.000-1.009], p = 0.039; HROS: 1.006 [95%CI: 1.001-1.011], p = 0.015). The CD4/CD8 cell ratio and its dynamics during therapy were strong predictors of PFS and OS with patients with a decreasing ratio between baseline and after 1-2 cycles having an improved median OS compared to patients with increasing values (p = 0.012, HR: 3.32). An immunological score combining sLAG3 and the CD4/CD8 ratio showed the highest predictive potential (HROS: 10.3).

CONCLUSION

Pending prospective validation, sLAG3 and correlating circulating T-cell subsets can be used as a non-invasive predictive marker to predict outcome to ICI therapy to help identifying ideal ICI candidates in the future.

Soluble Immune Checkpoint Molecules as Predictors of Efficacy in Immuno-Oncology Combination Therapy in Advanced Renal Cell Carcinoma

Immuno-oncology (IO) combination therapy is the first-line treatment for advanced renal cell carcinoma (RCC). However, biomarkers for predicting the response to IO combination therapy are lacking. Here, we investigated the association between the expression of soluble immune checkpoint molecules and the therapeutic efficacy of IO combination therapy in advanced RCC. The expression of soluble programmed cell death-1 (sPD-1), soluble programmed cell death ligand-1 (sPD-L1), soluble PD-L2 (sPD-L2), and lymphocyte activation gene-3 (sLAG-3) was assessed in plasma samples from 42 patients with advanced RCC who received first-line IO combination therapy. All IMDC risk classifications were represented among the patients, including 14.3, 57.1, and 28.6% with favorable, intermediate, and poor risk, respectively. Univariate analysis revealed that prior nephrectomy, sPD-L2 levels, and sLAG-3 levels were significant factors affecting progression-free survival (PFS), whereas multivariate analyses suggested that sPD-L2 and sLAG-3 levels were independent prognostic factors for PFS. In a univariate analysis of the overall survival, prior nephrectomy and sPD-L2 levels were significant factors; no significant differences were observed in the multivariate analysis. No significant correlation was observed between the sPD-L2 and sLAG-3 levels and PD-L2 and LAG-3 expression via immunohistochemistry. In conclusion, sPD-L2 and sLAG-3 expression may serve as a potential biomarker for predicting IO combination therapy efficacy.

LAG-3, TIM-3, and TIGIT: Distinct functions in immune regulation

LAG-3, TIM-3, and TIGIT comprise the next generation of immune checkpoint receptors being harnessed in the clinic. Although initially studied for their roles in restraining T cell responses, intense investigation over the last several years has started to pinpoint the unique functions of these molecules in other immune cell types. Understanding the distinct processes that these receptors regulate across immune cells and tissues will inform the clinical development and application of therapies that either antagonize or agonize these receptors, as well as the profile of potential tissue toxicity associated with their targeting. Here, we discuss the distinct functions of LAG-3, TIM-3, and TIGIT, including their contributions to the regulation of immune cells beyond T cells, their roles in disease, and the implications for their targeting in the clinic.

Lymphocyte-activation gene 3 (LAG-3) as a promising immune checkpoint in cancer immunotherapy: From biology to the clinic

In recent years, there have been notable advancements in the field of cancer immunotherapy, namely in the area of immune checkpoint inhibition. The Lymphocyte-activation gene 3 (LAG-3) has garnered attention as a potentially valuable focus of study in this particular field. The present study examines the biological aspects of LAG-3, its clinical consequences, and the potential therapeutic opportunities associated with its modulation. LAG-3, similar to CD4, has a regulatory role in modulating the immune system. The upregulation of this protein inside the neoplastic milieu hampers the immune system's ability to mount an effective response, hence enabling the evasion of cancer cells from immune surveillance. The LAG-3 protein interacts with ligands, inhibiting cytotoxic immune cells such as CD8+ T cells and NK cells. The potential of LAG-3 inhibitors presents intriguing prospects. Integrating these medicines with established treatments like PD-1/PD-L1 or CTLA-4 inhibitors can broaden the range of available therapy choices and address resistance issues. The advent of personalized therapy is imminent, as evidenced by the utilization of predictive biomarkers such as LAG-3 expression to inform individualized therapeutic approaches. Additionally, inhibitors of LAG-3 exhibit promise in addressing immunological depletion and resistance by revitalizing T cells and producing durable immune responses. The realization of LAG-3's promise necessitates global collaboration and equal access. Multinational trials are expected to ascertain the efficacy of the intervention in various patient groups.

The role of immune checkpoints in antitumor response: a potential antitumor immunotherapy

Immunotherapy aims to stimulate the immune system to inhibit tumor growth or prevent metastases. Tumor cells primarily employ altered expression of human leukocyte antigen (HLA) as a mechanism to avoid immune recognition and antitumor immune response. The antitumor immune response is primarily mediated by CD8+ cytotoxic T cells (CTLs) and natural killer (NK) cells, which plays a key role in the overall anti-tumor immune response. It is crucial to comprehend the molecular events occurring during the activation and subsequent regulation of these cell populations. The interaction between antigenic peptides presented on HLA-I molecules and the T-cell receptor (TCR) constitutes the initial signal required for T cell activation. Once activated, in physiologic circumstances, immune checkpoint expression by T cells suppress T cell effector functions when the antigen is removed, to ensures the maintenance of self-tolerance, immune homeostasis, and prevention of autoimmunity. However, in cancer, the overexpression of these molecules represents a common method through which tumor cells evade immune surveillance. Numerous therapeutic antibodies have been developed to inhibit immune checkpoints, demonstrating antitumor activity with fewer side effects compared to traditional chemotherapy. Nevertheless, it's worth noting that many immune checkpoint expressions occur after T cell activation and consequently, altered HLA expression on tumor cells could diminish the clinical efficacy of these antibodies. This review provides an in-depth exploration of immune checkpoint molecules, their corresponding blocking antibodies, and their clinical applications.

Regulatory T cells in gastric cancer: Key controllers from pathogenesis to therapy

Gastric cancer (GC) is a highly aggressive malignancy that remains a significant contributor to cancer-related mortality worldwide, despite a decline in incidence in recent years. Early-stage GC poses a diagnostic challenge due to its asymptomatic nature, leading to poor prognoses for most patients. Conventional treatment approaches, including chemotherapy and surgery, have shown limited efficacy in improving outcomes for GC patients. The advent of immune checkpoint inhibitors (ICIs) has revolutionized cancer therapy, yielding durable responses across various malignancies. However, the clinical benefits of ICIs in GC have been modest, underscoring the need for a comprehensive understanding of immune cell functions within the GC tumor microenvironment (TME). Regulatory T cells (Tregs), a subset of T lymphocytes, play a pivotal role in GC development and progression and serve as prognostic biomarkers for GC patients. This review aims to elucidate the multifaceted roles of Tregs in the pathogenesis, progression, and prognosis of gastric cancer, and establish their actual and future potential as therapeutic targets. By providing insights into the intricate interplay between Tregs and the TME, this review strives to stimulate further investigation and facilitate the development of targeted Treg-based therapeutic strategies for GC.

Immune checkpoints and cancer immunotherapies: insights into newly potential receptors and ligands

Checkpoint markers and immune checkpoint inhibitors have been increasingly identified and developed as potential immunotherapeutic targets in various human cancers. Despite valuable efforts to discover novel immune checkpoints and their ligands, the precise roles of their therapeutic functions, as well as the broad identification of their counterpart receptors, remain to be addressed. In this context, it has been suggested that various putative checkpoint receptors can be induced upon activation. In the tumor microenvironment, T cells, as crucial immune response against malignant diseases as well as other immune central effector cells, such as natural killer cells, are regulated via co-stimulatory or co-inhibitory signals from immune or tumor cells. Studies have shown that exposure of T cells to tumor antigens upregulates the expression of inhibitory checkpoint receptors, leading to T-cell dysfunction or exhaustion. Although targeting immune checkpoint regulators has shown relative clinical efficacy in some tumor types, most trials in the field of cancer immunotherapies have revealed unsatisfactory results due to de novo or adaptive resistance in cancer patients. To overcome these obstacles, combinational therapies with newly discovered inhibitory molecules or combined blockage of several checkpoints provide a rationale for further research. Moreover, precise identification of their receptors counterparts at crucial checkpoints is likely to promise effective therapies. In this review, we examine the prospects for the application of newly emerging checkpoints, such as T-cell immunoglobulin and mucin domain 3, lymphocyte activation gene-3, T-cell immunoreceptor with Ig and ITIM domains (TIGIT), V-domain Ig suppressor of T-cell activation (VISTA), new B7 family proteins, and B- and T-cell lymphocyte attenuator, in association with immunotherapy of malignancies. In addition, their clinical and biological significance is discussed, including their expression in various human cancers, along with their roles in T-cell-mediated immune responses.

LAG-3 Inhibitors: Novel Immune Checkpoint Inhibitors Changing the Landscape of Immunotherapy

One of the most important steps forward in the management of cancer was the discovery of immunotherapy. It has become an essential pillar in the treatment paradigm of cancer patients. Unfortunately, despite the various options presented with immune checkpoint inhibitors (ICIs), the benefit is still limited to select patients and the vast majority of these patients gain either minimal benefit or eventually progress, leaving an unmet need for the development of novel therapeutic agents and strategies. Lymphocyte activation gene-3 (LAG-3), an immune checkpoint receptor protein, is a molecule found on the surface of activated T-cells. It plays a major role in negatively regulating T-cell function thereby providing tumors with an immune escape in the tumor microenvironment (TME). Given its importance in regulating the immune system, LAG-3 has been considered as a promising target in oncology and precision medicine. To date, two LAG-3-directed agents (eftilagimod alpha and relatlimab) have been approved in combination with programmed death-1 (PD-1) inhibitors in the setting of advanced solid tumors. In this review, we discuss the structure of LAG-3, its mechanism of action, and its interaction with its ligands. We also shed light on the emerging treatments targeting LAG-3 for the treatment of solid tumors.

Multiplex serum immune profiling reveals circulating LAG-3 is associated with improved patient survival in high grade serous ovarian cancer

OBJECTIVE

High grade serous ovarian cancer (HGSOC) exhibits low response rates to clinically available immunotherapies. Nevertheless, emerging research has demonstrated that certain immune factors are predictive for HGSOC patient clinical outcomes, with our own groups previous work demonstrating that intratumoral levels of the immune checkpoint receptor LAG-3 is associated with improved patient survival. In this current study we sought to uncover non-invasive circulating immune prognostic and predictive signatures in HGSOC.

METHODS

A multiplex approach was employed that examined circulating levels of immune checkpoint receptors LAG-3 and PD-1 along with 48 common cytokine and chemokines in a cohort of 75 HGSOC treatment naïve patient serum samples.

RESULTS

Elevated serum LAG-3 was significantly associated with improved progression-free survival (PFS) and overall survival (OS) in HGSOC, while circulating PD-1 levels were largely unrelated with patient clinical outcomes. Cytokine and chemokine analysis revealed lower IL-15 expression correlated with improved PFS and OS, while increased IL-1α, IL-1Ra, IL-6, IL8 and VEGF were significantly associated with preoperative CA-125 levels. ROC analysis demonstrated that serum LAG-3 levels exhibited consistent reasonable predictability as a single agent.

CONCLUSIONS

Serum-derived LAG-3 was identified out of a diverse array of chemokine and cytokines as the immune-based factor most significantly associated with improved HGSOC survival. These findings suggest that LAG-3 could be implemented as a non-invasive patient predictive marker for improved HGSOC clinical outcomes.

Prediction of risk and overall survival of pancreatic cancer from blood soluble immune checkpoint-related proteins

Background

Immune checkpoint inhibition holds promise as a novel treatment for pancreatic ductal adenocarcinoma (PDAC). The clinical significance of soluble immune checkpoint (ICK) related proteins have not yet fully explored in PDAC.

Methods

We comprehensively profiled 14 soluble ICK-related proteins in plasma in 70 PDAC patients and 70 matched healthy controls. Epidemiological data of all subjects were obtained through structured interviews, and patients' clinical data were retrieved from electronical health records. We evaluated the associations between the biomarkers with the risk of PDAC using unconditional multivariate logistic regression. Consensus clustering (k-means algorithm) with significant biomarkers was performed to identify immune subtypes in PDAC patients. Prediction models for overall survival (OS) in PDAC patients were developed using multivariate Cox proportional hazards regression. Harrell's concordance index (C-index), time-dependent receiver operating characteristic (ROC) curve and calibration curve were utilized to evaluate performance of prediction models. Gene expressions of the identified ICK-related proteins in tumors from TCGA were analyzed to provide insight into underlying mechanisms.

Results

Soluble BTLA, CD28, CD137, GITR and LAG-3 were significantly upregulated in PDAC patients (all q < 0.05), and elevation of each of them was correlated with PDAC increased risk (all p < 0.05). PDAC patients were classified into soluble immune-high and soluble immune-low subtypes, using these 5 biomarkers. Patients in soluble immune-high subtype had significantly poorer OS than those in soluble immune-low subtype (log-rank p = 9.7E-03). The model with clinical variables and soluble immune subtypes had excellent predictive power (C-index = 0.809) for the OS of PDAC patients. Furthermore, the immune subtypes identified with corresponding genes' expression in PDAC tumor samples in TCGA showed an opposite correlation with OS to that of immune subtypes based on blood soluble ICK-related proteins (log-rank p =0.02). The immune-high subtype tumors displayed higher cytolytic activity (CYT) score than immune-low subtype tumors (p < 2E-16).

Conclusion

Five soluble ICK-related proteins were identified to be significantly associated with the risk and prognosis of PDAC. Patients who were classified as soluble immune-low subtype based on these biomarkers had better overall survival than those of the soluble immune-high subtype.

Immune Checkpoint Profiling in Humanized Breast Cancer Mice Revealed Cell-Specific LAG-3/PD-1/TIM-3 Co-Expression and Elevated PD-1/TIM-3 Secretion

Checkpoint blockade is particularly based on PD-1/PD-L1-inhibiting antibodies. However, an efficient immunological tumor defense can be blocked not only by PD-(L)1 but also by the presence of additional immune checkpoint molecules. Here, we investigated the co-expression of several immune checkpoint proteins and the soluble forms thereof (e.g., PD-1, TIM-3, LAG-3, PD-L1, PD-L2 and others) in humanized tumor mice (HTM) simultaneously harboring cell line-derived (JIMT-1, MDA-MB-231, MCF-7) or patient-derived breast cancer and a functional human immune system. We identified tumor-infiltrating T cells with a triple-positive PD-1, LAG-3 and TIM-3 phenotype. While PD-1 expression was increased in both the CD4 and CD8 T cells, TIM-3 was found to be upregulated particularly in the cytotoxic T cells in the MDA-MB-231-based HTM model. High levels of soluble TIM-3 and galectin-9 (a TIM-3 ligand) were detected in the serum. Surprisingly, soluble PD-L2, but only low levels of sPD-L1, were found in mice harboring PD-L1-positive tumors. Analysis of a dataset containing 3039 primary breast cancer samples on the R2 Genomics Analysis Platform revealed increased TIM-3, galectin-9 and LAG-3 expression, not only in triple-negative breast cancer but also in the HER2⁺ and hormone receptor-positive breast cancer subtypes. These data indicate that LAG-3 and TIM-3 represent additional key molecules within the breast cancer anti-immunity landscape.

Acidosis significantly alters immune checkpoint expression profiles of T cells from oesophageal adenocarcinoma patients

Tumour acidosis contributes to cancer progression by inhibiting anti-tumour immunity. However, the effect of acidosis on anti-tumour T cell phenotypes in oesophageal adenocarcinoma (OAC) is unknown. Therefore, this study investigated the effect of acidosis on anti-tumour T cell profiles and if immune checkpoint blockade (ICB) could enhance anti-tumour T cell immunity under acidosis. Acidic conditions substantially altered immune checkpoint expression profiles of OAC patient-derived T cells, upregulating TIM-3, LAG-3 and CTLA-4. Severe acidosis (pH 5.5) significantly decreased the percentage of central memory CD4⁺ T cells, an effect that was attenuated by ICB treatment. ICB increased T cell production of IFN-γ under moderate acidosis (pH 6.6) but not severe acidosis (pH 5.5) and decreased IL-10 production by T cells under severe acidic conditions only. A link between lactate and metastasis was also depicted; patients with nodal metastasis had higher serum lactate levels (p = 0.07) which also positively correlated with circulating levels of pro-angiogenic factor Tie-2. Our findings establish that acidosis-induced upregulation of immune checkpoints on T cells may potentially contribute to immune evasion and disease progression in OAC. However, acidic conditions curtailed ICB efficacy, supporting a rationale for utilizing systemic oral buffers to neutralize tumour acidity to improve ICB efficacy. Study schematic-PBMCs were isolated from OAC patients (A) and expanded ex vivo for 7 days using anti-CD3/28 +IL-2 T cell activation protocol (B) and further cultured for 48 h under increasing acidic conditions in the absence or presence of immune checkpoint blockade (nivolumab, ipilimumab or dual nivolumab + ipilimumab) (C). Immunophenotyping was then carried out to assess immune checkpoint expression profiles and anti-tumour T cell phenotypes (D). Serum lactate was assessed in OAC patients (E-F) and levels were correlated with patient demographics (G) and the levels of circulating immune/pro-angiogenic cytokines that were determined by multiplex ELISA (H). Key Findings-severe acidic conditions upregulated multiple immune checkpoints on T cells (I). Efficacy of ICB was curtailed under severe acidic conditions (J). Circulating lactate levels positively correlated with circulating levels of pro-angiogenic factor tie-2 and higher serum lactate levels were found in patients who had nodal metastasis (K).

Clinical Significance of Soluble LAG-3 (sLAG-3) in Patients With Cervical Cancer Determined via Enzyme-Linked Immunosorbent Assay With Monoclonal Antibodies

Background: The tumor microenvironment and tumor immunity have become the focus of research on tumor diagnosis and treatment. Lymphocyte activation gene-3 (LAG-3, CD223) is a newly discovered immunosuppressive receptor that is abnormally expressed in various tumor microenvironments and plays an important role as an immune checkpoint in the tumor immune response. Objective: We developed a novel enzyme-linked immunosorbent assay kit, examined the levels of soluble LAG-3 (sLAG-3) in the serum of patients with cervical cancer, and identified new biomarkers for cervical cancer development. Methods: To investigate the potential biological function of sLAG-3, we generated and characterized 2 novel anti-LAG-3 monoclonal antibodies, namely 4F4 and 4E12. We performed western blotting, immunofluorescence, and immunohistochemistry using hybridoma technology and an enzyme-linked immunosorbent assay kit for detecting human sLAG-3 based on an improved double-antibody sandwich enzyme-linked immunosorbent assay method. The stability and sensitivity of these kits were also assessed. Results: We screened and characterized 2 novel monoclonal antibodies against human LAG-3. The enzyme-linked immunosorbent assay kit also includes a wide range of tests. Using this enzyme-linked immunosorbent assay system, we found that the expression level of sLAG-3 in the peripheral blood of patients with cervical cancer significantly decreased as the disease progressed (P < .0001). Multivariate logistic regression analysis revealed that low sLAG-3 expression was an independent predictor of cervical cancer and related diseases (P < .05). Furthermore, receiver operating characteristic curve analysis showed that sLAG-3 had diagnostic value for cervical cancer metastasis (P < .0001). Conclusion: These data suggest that sLAG-3 is a potential biomarker for cervical cancer development. Therefore, this kit has a certain application value in the diagnosis of cervical cancer.

Molecular Pathways and Mechanisms of LAG3 in Cancer Therapy

Immunotherapy targeting coinhibitory receptors has been highly successful in treating a wide variety of malignancies; however, only a subset of patients exhibits durable responses. The first FDA-approved immunotherapeutics targeting coinhibitory receptors PD1 and CTLA4, alone or in combination, significantly improved survival but were also accompanied by substantial toxicity in combination. The third FDA-approved immune checkpoint inhibitor targets LAG3, a coinhibitory receptor expressed on activated CD4+ and CD8+ T cells, especially in settings of long-term antigenic stimulation, such as chronic viral infection or cancer. Mechanistically, LAG3 expression limits both the expansion of activated T cells and the size of the memory pool, suggesting that LAG3 may be a promising target for immunotherapy. Importantly, the mechanism(s) by which LAG3 contributes to CD8+ T-cell exhaustion may be distinct from those governed by PD1, indicating that the combination of anti-LAG3 and anti-PD1 may synergistically enhance antitumor immunity. Clinical studies evaluating the role of anti-LAG3 in combination with anti-PD1 are underway, and recent phase III trial results in metastatic melanoma demonstrate both the efficacy and safety of this combination. Further ongoing clinical trials are evaluating this combination across multiple tumor types and the adjuvant setting, with accompanying translational and biomarker-focused studies designed to elucidate the molecular pathways that lead to improved antitumor T-cell responses following dual blockade of PD1 and LAG3. Overall, LAG3 plays an important role in limiting T-cell activation and has now become part of the repertoire of combinatorial immunotherapeutics available for the treatment of metastatic melanoma.

Integrated analysis of Helicobacter pylori-related prognostic gene modification patterns in the tumour microenvironment of gastric cancer

Background

Helicobacter pylori (HP) infection is one of the leading causes of gastric cancer (GC). However, the interaction between HP and the TME, and its carcinogenic mechanism remains unknown.

Methods

The HP-related prognostic genes were identified based on HP infection-related gene markers and HP infection sample datasets by risk method and NMF algorithm. Principal component analysis (PCA) algorithm was used to constructed the HPscore system. The “limma” R package was employed to determine differentially expressed genes. In addition, the R packages, such as “xCell” and “GSVA”, was used to analyze the relationship between the HPscore and tumor microenvironment. Finally, quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to verify the expression levels of 28 HP-related prognostic genes in tissues.

Results

We successfully identified 28 HP-related prognostic genes that accurately classified the GC population. There are significant differences in survival between different subgroups (high-, low-risk and cluster_1,2). Thereafter, the HPscore system was constructed to evaluate the signatures of the 28 HP-related prognostic genes. The overall survival rate in the high-HPscore group was poor and immunological surveillance was reduced, whereas the low-HPscore group had a survival advantage and was related to the inflammatory response. HPscore was also strongly correlated with the tumour stage, TME cell infiltration and stemness. The qRT-PCR results showed that DOCK4 expression level of 28 HP-related prognostic genes was higher in gastric cancer tissues than in adjacent tissues.

Conclusions

HP signatures play a crucial role in the TME and tumourigenesis. HPscore evaluation of a single tumour sample can help identify the TME characteristics and the carcinogenic mechanism of GC patients infected with HP, based on which personalized treatment can be administered.

The relationship between soluble lymphocyte activation gene-3 and coronary artery disease

Background

Soluble lymphocyte activation gene 3 (sLAG3) may be used for diagnosis or prognosis in various diseases. However, the relationship between sLAG3 and coronary artery disease (CAD) are still unclear. This study aimed to investigate the levels of sLAG3 in patients with CAD, and its potential clinical association with the disease.

Methods

A total of 66 subjects (49 patients with CAD and 17 control subjects without CAD) were enrolled. The sLAG3 level was measured using enzyme-linked immunosorbent assay (ELISA) kits. Clinical variables included demographics, biochemical markers, coronary angiography status, and ejection fraction of the heart (EF) were collected, and Gensini scores were calculated. LAG3 gene data was extracted from three datasets (GSE23561, GSE61144, GSE60993) in Gene Expression Omnibus (GEO) to compare differential expression between CAD and control subjects.

Results

The sLAG3 level was significantly lower in the CAD vs. the controls (P < 0.05), and negatively associated with CAD [odds ratio (OR): 0.212, 95% confidential interval (CI): 0.060–0.746, P < 0.05]. Furthermore, the area under the curve (AUC) of sLAG3 level was significant (P < 0.05). The sLAG3 level in subjects with body mass index (BMI) ≥ 24 kg/m² was lower compared to those with BMI < 24 kg/m² (P < 0.05). The sLAG3 level was also negatively associated with BMI and diabetes mellitus (P < 0.05), though not associated with the Gensini scores or EF (P > 0.05). Lastly, the LAG3 gene expression in peripheral whole blood of patients with CAD were down-regulated compared to healthy controls (P < 0.05).

Conclusion

The sLAG3 level was negatively associated with the occurrence but not severity of CAD. Meanwhile, the sLAG3 was negatively associated with BMI and diabetes mellitus, suggesting the reduced sLAG3 might be a novel risk factor for developing CAD.

Application progress of liquid biopsy in gastric cancer

Gastric cancer (GC) is one of the most common malignant tumors globally. Guiding the individualized treatment of GC is the focus of research. Obtaining representative biological samples to study the biological characteristics of GC is the focus of diagnosis and treatment of GC. Liquid biopsy technology can use high-throughput sequencing technology to detect biological genetic information in blood. Compared with traditional tissue biopsy, liquid biopsy can determine the dynamic changes of tumor. As a noninvasive auxiliary diagnostic method, liquid biopsy can provide diagnostic and prognostic information concerning the progression of the disease. Liquid biopsy includes circulating tumor cells, circulating tumor DNA, circulating tumor RNA, tumor educated platelets, exosomes, and cytokines. This article describes the classification of liquid biopsy and its application value in the occurrence, development, and therapeutic efficacy of GC.

LAG-3 as a Potent Target for Novel Anticancer Therapies of a Wide Range of Tumors

LAG-3 (Lymphocyte activation gene 3) protein is a checkpoint receptor that interacts with LSEC-tin, Galectin-3 and FGL1. This interaction leads to reduced production of IL-2 and IFN-γ. LAG-3 is widely expressed in different tumor types and modulates the tumor microenvironment through immunosuppressive effects. Differential expression in various tumor types influences patient prognosis, which is often associated with coexpression with immune checkpoint inhibitors, such as TIM-3, PD-1 and CTLA-4. Here, we discuss expression profiles in different tumor types. To date, many clinical trials have been conducted using LAG-3 inhibitors, which can be divided into anti-LAG-3 monoclonal antibodies, anti-LAG-3 bispecifics and soluble LAG-3-Ig fusion proteins. LAG-3 inhibitors supress T-cell proliferation and activation by disallowing for the interaction between LAG-3 to MHC-II. The process enhances anti-tumor immune response. In this paper, we will review the current state of knowledge on the structure, function and expression of LAG-3 in various types of cancer, as well as its correlation with overall prognosis, involvement in cell-based therapies and experimental medicine. We will consider the role of compounds targeting LAG-3 in clinical trials both as monotherapy and in combination, which will provide data relating to the efficacy and safety of proposed drug candidates.

Advances in molecular biomarkers research and clinical application progress for gastric cancer immunotherapy

Gastric cancer is characterized by high morbidity and mortality worldwide. Early-stage gastric cancer is mainly treated with surgery, while for advanced gastric cancer, the current treatment options remain insufficient. In the 2022 NCCN Guidelines for Gastric Cancer, immunotherapy is listed as a first-line option for certain conditions. Immunotherapy for gastric cancer mainly targets the PD-1 molecule and achieves therapeutic effects by activating T cells. In addition, therapeutic strategies targeting other molecules, such as CTLA4, LAG3, Tim3, TIGIT, and OX40, have also been developed to improve the treatment efficacy of gastric cancer immunotherapy. This review summarizes the molecular biomarkers of gastric cancer immunotherapy and their clinical trials.

Circulating and Tumor-Infiltrating Immune Checkpoint-Expressing CD8+ Treg/T Cell Subsets and Their Associations with Disease-Free Survival in Colorectal Cancer Patients

Simple Summary

Colorectal cancer is one of the leading causes of global cancer-related mortality. Tumor-infiltrating effector immune cells play critical roles in tumor control, and their activity can dictate disease outcomes. In this study, we provide evidence of the associations between different CD8⁺ T cell subpopulations with disease-free survival (DFS) in CRC patients. We report associations between higher levels of certain circulating and tumor-infiltrating CD8⁺ T cell subsets and improved clinical outcomes in CRC patients.

Abstract

T cells in the tumor microenvironment (TME) have diverse roles in anti-tumor immunity, including orchestration of immune responses and anti-tumor cytotoxic attack. However, different T cell subsets may have opposing roles in tumor progression, especially in inflammation-related cancers such as colorectal cancer (CRC). In this study, we phenotypically characterized CD3⁺CD4^- (CD8⁺) T cells in colorectal tumor tissues (TT), normal colon tissues (NT) and in circulation of CRC patients. We investigated the expression levels of key immune checkpoints (ICs) and Treg-related markers in CD8⁺ T cells. Importantly, we investigated associations between different tumor-infiltrating CD8⁺ T cell subpopulations and disease-free survival (DFS) in CRC patients. We found that FoxP3 expression and ICs including PD-1, CTLA-4, TIM-3, and LAG-3 were significantly increased in tumor-infiltrating CD8⁺ T cells compared with NT and peripheral blood. In the TME, we found that TIM-3 expression was significantly increased in patients with early stages and absent lymphovascular invasion (LVI) compared to patients with advanced stages and LVI. Importantly, we report that high levels of certain circulating CD8⁺ T cell subsets (TIM-3-expressing, FoxP3⁻Helios⁻TIM-3⁺ and FoxP3⁻Helios⁺TIM-3⁺ cells) in CRC patients were associated with better DFS. Moreover, in the TME, we report that elevated levels of CD25⁺ and TIM-3⁺ T cells, and FoxP3⁺Helios⁻TIM-3⁺ Tregs were associated with better DFS.

Novel Immune Checkpoints in Esophageal Cancer: From Biomarkers to Therapeutic Targets

Esophageal cancer ranks as the sixth most common cause of cancer death worldwide. Due to the limited efficacy of conventional therapeutic strategies, including surgery, chemotherapy, and radiotherapy, treatments are still far from satisfactory in terms of survival, prompting the search for novel treatment methods. Immune checkpoints play crucial roles in immune evasion mediated by tumor cells, and successful clinical outcomes have been achieved via blocking these pathways. However, only a small fraction of patients can benefit from current immune checkpoint inhibitors targeting programmed cell death ligand-1 (PD-L1) and cytotoxic T-lymphocyte-associated protein-4. Unfortunately, some patients show primary and/or acquired resistance to immune checkpoint inhibitors. Until now, novel immune checkpoint pathways have rarely been studied in esophageal cancer, and there is a great need for biomarkers to predict who will benefit from existing strategies. Herein, we primarily discuss the roles of new immune checkpoints as predictive biomarkers and therapeutic targets for esophageal cancer. In addition, we summarize the ongoing clinical trials and provide future research directions targeting these pathways.

A Comprehensive Analysis of Plasma Cytokines and Metabolites Shows an Association between Galectin-9 and Changes in Peripheral Lymphocyte Subset Percentages Following Coix Seed Consumption

We previously reported that healthy adult males who consumed coix seeds for 1 week demonstrated an increased intestinal abundance of Faecalibacterium prausnitzii and altered peripheral lymphocyte subset percentages. However, the mechanism underlining these effects has not been elucidated. Therefore, cytokines and metabolites in plasma obtained in this study are comprehensively analyzed. A total of 56 cytokines and 52 metabolites in the plasma are quantified. Among them, 14 cytokines and 9 metabolites show significant changes in their levels following coix seed consumption. We examine the relationship between these changes and those in peripheral lymphocyte subset percentages and intestinal abundance of F. prausnitzii, which is also considerably altered following coix seed consumption. The galectin-9 concentration considerably decreased after coix seed consumption, and these changes correlate with those in cytotoxic T cells and pan T cells. Therefore, galectin-9 is possibly involved in the changes in peripheral lymphocyte subset percentages induced by coix seed consumption.

Concurrent Chemoradiotherapy Increases the Levels of Soluble Immune Checkpoint Proteins in Patients with Locally Advanced Cervical Cancer

Purpose

Concurrent chemoradiotherapy (CCRT) has been widely applied to locally advanced cervical cancer (LACC) patients, inducing the massive release of antigen and systematic immunomodulatory effects. However, its effect on the soluble immune checkpoint proteins (sICPs) remains unclear, which might play a key role in the immune response. Therefore, the current study explored changes in the levels of 16 sICPs in LACC patients during CCRT.

Methods

We prospectively enrolled fifty-one LACC patients treated with CCRT and collected patients' blood before, during and after CCRT. The levels of 16 sICPs were measured using the Luminex platform, and the changes were measured using Friedman test with Bonferroni's posttest. One month after CCRT, the tumor response was evaluated according to the RECIST 1.1 guidelines.

Results

The levels of soluble T-cell immunoglobulin and mucin-domain containing-3 (sTIM-3) significantly increased during CCRT (P = 0.041), while those of the soluble B and T lymphocyte attenuator (sBTLA), sCD40, soluble glucocorticoid-induced tumor necrosis factor receptor ligand (sGITRL), sCD80, sCD86, sPD-1, sPD-L1, sCTLA-4, and soluble inducible T-cell costimulator (sICOS) significantly increased after CCRT (all P < 0.05). Other sICPs showed no significant changes throughout the CCRT (all P > 0.05). 41 (80%), 8 (16%), and 2 (4%) patients showed complete response (CR), partial response (PR), and stable disease (SD) after CCRT, respectively. Interestingly, the level of soluble lymphocyte-activation gene 3 (sLAG-3) was significantly higher among the PR/SD patients as compared to the CR after CCRT (P = 0.009).

Conclusions

This study revealed that CCRT might elevate the serum levels of sTIM-3, sBTLA, sCD40, sGITRL, sCD80, sCD86, sPD-1, sPD-L1, sCTLA-4, and sICOS in the patients with LACC. The sLAG-3 level was higher in the patients with poor response to CCRT. These findings revealed the dynamic changes in the sICPs levels during CCRT, which might be helpful in designing optimal treatment strategies for LACC patients.

Key Players of the Immunosuppressive Tumor Microenvironment and Emerging Therapeutic Strategies

The tumor microenvironment (TME) is a complex, dynamic battlefield for both immune cells and tumor cells. The advent of the immune checkpoint inhibitors (ICI) since 2011, such as the anti-cytotoxic T-lymphocyte associated protein (CTLA)-4 and anti-programmed cell death receptor (PD)-(L)1 antibodies, provided powerful weapons in the arsenal of cancer treatments, demonstrating unprecedented durable responses for patients with many types of advanced cancers. However, the response rate is generally low across tumor types and a substantial number of patients develop acquired resistance. These primary or acquired resistance are attributed to various immunosuppressive elements (soluble and cellular factors) and alternative immune checkpoints in the TME. Therefore, a better understanding of the TME is absolutely essential to develop therapeutic strategies to overcome resistance. Numerous clinical studies are underway using ICIs and additional agents that are tailored to the characteristics of the tumor or the TME. Some of the combination treatments are already approved by the Food and Drug Administration (FDA), such as platinum-doublet chemotherapy, tyrosine kinase inhibitor (TKI) -targeting vascular endothelial growth factor (VEGF) combined with anti-PD-(L)1 antibodies or immuno-immuno combinations (anti-CTLA-4 and anti-PD-1). In this review, we will discuss the key immunosuppressive cells, metabolites, cytokines or chemokines, and hypoxic conditions in the TME that contribute to tumor immune escape and the prospect of relevant clinical trials by targeting these elements in combination with ICIs.

The Impact of Esophageal Oncological Surgery on Perioperative Immune Function; Implications for Adjuvant Immune Checkpoint Inhibition

Background

Immune checkpoint inhibitors (ICIs) are being investigated for their role as an adjunct in the multimodal treatment of esophageal adenocarcinoma (EAC). The most effective time to incorporate ICIs remains unknown. Our study profiles systemic anti-tumor immunity perioperatively to help inform the optimal timing of ICIs into current standards of care for EAC patients.

Methods

Systemic immunity in 11 EAC patients was phenotyped immediately prior to esophagectomy (POD-0) and post-operatively (POD)-1, 3, 7 and week 6. Longitudinal serological profiling was conducted by ELISA. The frequency of circulating lymphocytes, activation status, immune checkpoint expression and damage-associated molecular patterns was assessed by flow cytometry.

Results

The frequency of naïve T-cells significantly increased in circulation post-esophagectomy from POD-0 to POD-7 (p<0.01) with a significant decrease in effector memory T-cells by POD7 followed by a subsequent increase by week 6 (p<0.05). A significant increase in activated circulating CD27⁺ T-cells was observed from POD-0 to POD-7 (p<0.05). The percentage of PD-1⁺ and CTLA-4⁺ T-cells peaked on POD-1 and was significantly decreased by week 6 (p<0.01). There was a significant increase in soluble PD-1, PD-L2, TIGIT and LAG-3 from POD-3 to week 6 (p<0.01). Increased checkpoint expression correlated with those who developed metastatic disease early in their postoperative course. Th1 cytokines and co-stimulatory factors decreased significantly in the immediate post-operative setting, with a reduction in IFN-γ, IL-12p40, IL-1RA, CD28, CD40L and TNF-α. A simultaneous increase was observed in Th2 cytokines in the immediate post-operative setting, with a significant increase in IL-4, IL-10, IL-16 and MCP-1 before returning to preoperative levels at week 6.

Conclusion

Our study highlights the prevailing Th2-like immunophenotype post-surgery. Therefore, shifting the balance in favour of a Th1-like phenotype would offer a potent therapeutic approach to promote cancer regression and prevent recurrence in the adjuvant setting and could potentially propagate anti-tumour immune responses perioperatively if administered in the immediate neoadjuvant setting. Consequently, this body of work paves the way for further studies and appropriate trial design is needed to further interrogate and validate the use of ICI in the multimodal treatment of locally advanced disease in the neoadjuvant and adjuvant setting.

Phase I, multicenter, open-label study of intravenous VCN-01 oncolytic adenovirus with or without nab-paclitaxel plus gemcitabine in patients with advanced solid tumors

BACKGROUND

VCN-01 is an oncolytic adenovirus (Ad5 based) designed to replicate in cancer cells with dysfunctional RB1 pathway, express hyaluronidase to enhance virus intratumoral spread and facilitate chemotherapy and immune cells extravasation into the tumor. This phase I clinical trial was aimed to find the maximum tolerated dose/recommended phase II dose (RP2D) and dose-limiting toxicity (DLT) of the intravenous delivery of the replication-competent VCN-01 adenovirus in patients with advanced cancer.

METHODS

Part I: patients with advanced refractory solid tumors received one single dose of VCN-01. Parts II and III: patients with pancreatic adenocarcinoma received VCN-01 (only in cycle 1) and nab-paclitaxel plus gemcitabine (VCN-concurrent on day 1 in Part II, and 7 days before chemotherapy in Part III). Patients were required to have anti-Ad5 neutralizing antibody (NAbs) titers lower than 1/350 dilution. Pharmacokinetic and pharmacodynamic analyses were performed.

RESULTS

26% of the patients initially screened were excluded based on high NAbs levels. Sixteen and 12 patients were enrolled in Part I and II, respectively: RP2D were 1×1013 viral particles (vp)/patient (Part I), and 3.3×1012 vp/patient (Part II). Fourteen patients were included in Part III: there were no DLTs and the RP2D was 1×1013 vp/patient. Observed DLTs were grade 4 aspartate aminotransferase increase in one patient (Part I, 1×1013 vp), grade 4 febrile neutropenia in one patient and grade 5 thrombocytopenia plus enterocolitis in another patient (Part II, 1×1013 vp). In patients with pancreatic adenocarcinoma overall response rate were 50% (Part II) and 50% (Part III). VCN-01 viral genomes were detected in tumor tissue in five out of six biopsies (day 8). A second viral plasmatic peak and increased hyaluronidase serum levels suggested replication after intravenous injection in all patients. Increased levels of immune biomarkers (interferon-γ, soluble lymphocyte activation gene-3, interleukin (IL)-6, IL-10) were found after VCN-01 administration.

CONCLUSIONS

Treatment with VCN-01 is feasible and has an acceptable safety. Encouraging biological and clinical activity was observed when administered in combination with nab-paclitaxel plus gemcitabine to patients with pancreatic adenocarcinoma.

TRIAL REGISTRATION NUMBER

NCT02045602.

Soluble Immune Checkpoints Are Dysregulated in COVID-19 and Heavy Alcohol Users With HIV Infection

Immune checkpoints (ICPs) consist of paired receptor-ligand molecules that exert inhibitory or stimulatory effects on immune defense, surveillance, regulation, and self-tolerance. ICPs exist in both membrane and soluble forms in vivo and in vitro. Imbalances between inhibitory and stimulatory membrane-bound ICPs (mICPs) in malignant cells and immune cells in the tumor immune microenvironment (TIME) have been well documented. Blockades of inhibitory mICPs have emerged as an immense breakthrough in cancer therapeutics. However, the origin, structure, production regulation, and biological significance of soluble ICPs (sICPs) in health and disease largely remains elusive. Soluble ICPs can be generated through either alternative mRNA splicing and secretion or protease-mediated shedding from mICPs. Since sICPs are found in the bloodstream, they likely form a circulating immune regulatory system. In fact, there is increasing evidence that sICPs exhibit biological functions including (1) regulation of antibacterial immunity, (2) interaction with their mICP compartments to positively or negatively regulate immune responses, and (3) competition with their mICP compartments for binding to the ICP blocking antibodies, thereby reducing the efficacy of ICP blockade therapies. Here, we summarize current data of sICPs in cancer and infectious diseases. We particularly focus on sICPs in COVID-19 and HIV infection as they are the two ongoing global pandemics and have created the world's most serious public health challenges. A "storm" of sICPs occurs in the peripheral circulation of COVID-19 patients and is associated with the severity of COVID-19. Similarly, sICPs are highly dysregulated in people living with HIV (PLHIV) and some sICPs remain dysregulated in PLHIV on antiretroviral therapy (ART), indicating these sICPs may serve as biomarkers of incomplete immune reconstitution in PLHIV on ART. We reveal that HIV infection in the setting of alcohol misuse exacerbates sICP dysregulation as PLHIV with heavy alcohol consumption have significantly elevated plasma levels of many sICPs. Thus, both stimulatory and inhibitory sICPs are present in the bloodstream of healthy people and their balance can be disrupted under pathophysiological conditions such as cancer, COVID-19, HIV infection, and alcohol misuse. There is an urgent need to study the role of sICPs in immune regulation in health and disease.

Update on lymphocyte-activation gene 3 (LAG-3) in cancers: from biological properties to clinical applications

Immunotherapy that targets checkpoints, especially programmed cell death protein 1 and programmed cell death ligand 1, has revolutionized cancer therapy regimens. The overall response rate to mono-immunotherapy, however, is limited, emphasizing the need to potentiate the efficacy of these regimens. The functions of immune cells are modulated by multiple stimulatory and inhibitory molecules, including lymphocyte activation gene 3 (LAG-3). LAG-3 is co-expressed together with other inhibitory checkpoints and plays key roles in immune suppression. Increasing evidence, particularly in the last 5 years, has shown the potential of LAG-3 blockade in anti-tumor immunity. This review provides an update on the biological properties and clinical applications of LAG-3 in cancers.

Presence of Tim3+ and PD-1+ CD8+ T cells identifies microsatellite stable colorectal carcinomas with immune exhaustion and distinct clinicopathological features

Colorectal carcinoma (CRC) is the second leading cause of cancer mortality worldwide. CRC is stratified into two major groups: microsatellite stable (MSS) and microsatellite instability-high (MSI-H). MSS CRC constitutes the majority of cases, has worse overall prognosis, and thus far has failed to respond to immunotherapies targeting the immune checkpoint receptors PD-1, PD-L1, and CTLA-4. Here, we examined the alternate immunotherapy targets Tim-3 and Lag-3, as well as PD-1, on immune cells in a cohort of MSS CRC using immunohistochemistry and flow cytometry together with mutational analysis and clinical data. We found that PD-1 was variably expressed across CD4⁺ tumor-infiltrating lymphocyte (TIL) subtypes, and Tim-3 was mostly restricted to CD4⁺ regulatory T cells. Lag-3, when detected by flow cytometry, was largely co-expressed with Tim-3 and PD-1 in CD4⁺ TILs. Furthermore, Tim-3⁺ PD-1⁺ CD8⁺ TILs accumulated in the tumor and exhibited a dysfunctional or "exhausted" phenotype. Notably, we observed a subset of patients with a high proportion of Tim-3^- PD-1^- CD8⁺ TILs and, conversely, a low proportion of Tim-3⁺ PD-1⁺ CD8⁺ TILs, thus stratifying MSS CRC patients based on a feature of immune exhaustion (MSS-ImmEx). MSS-ImmEx^hi patients had abundant Tim-3⁺ PD-1⁺ CD8⁺ TILs, PD-1⁺ CD4⁺ effector and regulatory T cells, and were enriched for left-sided colon tumors and mutations in the APC tumor-suppressor gene. We further investigated the spatial organization of Tim-3, Lag-3, PD-1, and PD-L1 by immunohistochemistry and found higher levels in the tumor margin; however, MSS-ImmEx^hi tumors exhibited a higher density of Tim-3⁺ cells in the tumor center over MSS-ImmEx^low tumors. Immunofluorescence revealed a higher density of PD-1⁺ /CD8⁺ cells in the tumor center in this group. Our findings identify a subset of MSS CRC that exhibits evidence of higher prior immune activation (MSS-ImmEx^hi ) in which therapies targeting Tim-3 in conjunction with anti-PD-1 or other immunotherapies may provide clinical benefit. This article is protected by copyright. All rights reserved.

Monitoring Circulating Immune Checkpoint Proteins as Predictors of Non-AIDS Morbid Events in People with HIV Initiating Antiretroviral Therapy

Background

Although cell surface immune checkpoint proteins (ICPs) such as PD-1 expressed on T cells are associated with T-cell exhaustion, HIV disease progression, and AIDS events, they have shown limited utility in predicting non-AIDS morbidity. Given that ICPs also exist in soluble forms and are elevated in ART-treated HIV infection, we tested the hypothesis that soluble ICPs may be predictive of non-AIDS events in adults initiating ART.

Methods

Utilizing a nested case–control study from the AIDS Clinical Trials Group ALLRT cohort, we measured plasma levels of 15 soluble inhibitory and activating ICPs by Luminex. Participants (134 cases, 292 matched controls) were evaluated pre-ART, a year post-ART, and immediately preceding a non-AIDS event, which included myocardial infarction (MI)/stroke, malignancy, serious bacterial infection, and nonaccidental death.

Results

Conditional logistic regression analysis determined that higher levels of soluble CD27 were associated with increased risk of non-AIDS events at all time points. Higher levels of CD40 at baseline and pre-event and CD80 at pre-event were associated with increased risk of non-AIDS events. Examining specific non-AIDS events, multiple ICPs were associated with malignancy at baseline and pre-event, whereas only higher CD27 levels were associated with increased risk of MI/stroke at year 1 and pre-event.

Conclusions

While select soluble ICPs were associated with non-AIDS events, CD27 emerged as a consistent marker irrespective of ART. Our data may offer guidance on new targets for early clinical monitoring in people with HIV who remain at greater risk of specific non-AIDS events.

Cancer Immunotherapy with Immune Checkpoint Inhibitors-Biomarkers of Response and Toxicity; Current Limitations and Future Promise

Immune checkpoint inhibitors are monoclonal antibodies that are used to treat over one in three cancer patients. While they have changed the natural history of disease, prolonging life and preserving quality of life, they are highly active in less than 40% of patients, even in the most responsive malignancies such as melanoma, and cause significant autoimmune side effects. Licenced biomarkers include tumour Programmed Death Ligand 1 expression by immunohistochemistry, microsatellite instability, and tumour mutational burden, none of which are particularly sensitive or specific. Emerging tumour and immune tissue biomarkers such as novel immunohistochemistry scores, tumour, stromal and immune cell gene expression profiling, and liquid biomarkers such as systemic inflammatory markers, kynurenine/tryptophan ratio, circulating immune cells, cytokines and DNA are discussed in this review. We also examine the influence of the faecal microbiome on treatment outcome and its use as a biomarker of response and toxicity.

Seven mysteries of LAG-3: a multi-faceted immune receptor of increasing complexity

Despite three decades of research to its name and increasing interest in immunotherapies that target it, LAG-3 remains an elusive co-inhibitory receptor in comparison to the well-established PD-1 and CTLA-4. As such, LAG-3 targeting therapies have yet to achieve the clinical success of therapies targeting other checkpoints. This could, in part, be attributed to the many unanswered questions that remain regarding LAG-3 biology. Of these, we address: (i) the function of the many LAG-3-ligand interactions, (ii) the hurdles that remain to acquire a high-resolution structure of LAG-3, (iii) the under-studied LAG-3 signal transduction mechanism, (iv) the elusive soluble form of LAG-3, (v) the implications of the lack of (significant) phenotype of LAG-3 knockout mice, (vi) the reports of LAG-3 expression on the epithelium, and (vii) the conflicting reports of LAG-3 expression (and potential contributions to pathology) in the brain. These mysteries which surround LAG-3 highlight how the ever-evolving study of its biology continues to reveal ever-increasing complexity in its role as an immune receptor. Importantly, answering the questions which shroud LAG-3 in mystery will allow the maximum therapeutic benefit of LAG-3 targeting immunotherapies in cancer, autoimmunity and beyond.

On Demand Biosensors for Early Diagnosis of Cancer and Immune Checkpoints Blockade Therapy Monitoring from Liquid Biopsy

Recently, considerable interest has emerged in the development of biosensors to detect biomarkers and immune checkpoints to identify and measure cancer through liquid biopsies. The detection of cancer biomarkers from a small volume of blood is relatively fast compared to the gold standard of tissue biopsies. Traditional immuno-histochemistry (IHC) requires tissue samples obtained using invasive procedures and specific expertise as well as sophisticated instruments. Furthermore, the turnaround for IHC assays is usually several days. To overcome these challenges, on-demand biosensor-based assays were developed to provide more immediate prognostic information for clinicians. Novel rapid, highly precise, and sensitive approaches have been under investigation using physical and biochemical methods to sense biomarkers. Additionally, interest in understanding immune checkpoints has facilitated the rapid detection of cancer prognosis from liquid biopsies. Typically, these devices combine various classes of detectors with digital outputs for the measurement of soluble cancer or immune checkpoint (IC) markers from liquid biopsy samples. These sensor devices have two key advantages: (a) a small volume of blood drawn from the patient is sufficient for analysis, and (b) it could aid physicians in quickly selecting and deciding the appropriate therapy regime for the patients (e.g., immune checkpoint blockade (ICB) therapy). In this review, we will provide updates on potential cancer markers, various biosensors in cancer diagnosis, and the corresponding limits of detection, while focusing on biosensor development for IC marker detection.

Immunotherapy for gastric cancer: a 2021 update

Gastric cancer, the fifth most frequent cancer and the fourth leading cause of cancer deaths, accounts for a devastating death rate worldwide. Since the majority of patients with gastric cancer are diagnosed at advanced stages, they are not suitable for surgery and present with locally advanced or metastatic disease. Recent advances in immunotherapy have elicited a considerable amount of attention as viable therapeutic options for several cancer types. This work presents a summary of the currently ongoing clinical trials and critically addresses the efficacy of a large spectrum of immunotherapy approaches in the general population for gastric cancer as well as in relation to tumor genetic profiling.

Serum LAG-3 Predicts Outcome and Treatment Response in Hepatocellular Carcinoma Patients With Transarterial Chemoembolization

Background

Transarterial chemoembolization (TACE) stands for the most commonly utilized therapy for hepatocellular carcinoma (HCC) worldwide. This study was to explore the potential predictive and prognostic roles of LAG-3 and PD-L1 as serum biomarkers in HCC patients underwent TACE treatment.

Methods

A total of 100 HCC patients receiving TACE as well as 30 healthy controls were enrolled in the study. Serum LAG-3 and PD-L1 levels were determined at baseline and 3 day after TACE using enzyme-linked immunosorbent assay (ELISA).

Results

We found serum levels of LAG-3 and PD-L1 were significantly elevated in HCC patients compared with healthy controls. Interestingly, patients with low pre-TACE and post-TACE levels of LAG-3 but not PD-L1 had a high probability of achieving an objective response (OR) after TACE treatment. Additionally, high pre-TACE LAG-3 level was correlated with poor disease outcome, and the patients with both high serum LAG-3 and PD-L1 level had the shorter overall survival (OS) than patients who are either PD-L1 or LAG-3 high or both PD-L1 and LAG-3 low. High pre-TACE serum LAG-3 level was positively associated with more cirrhosis pattern, advanced BCLC stage, pre-TACE alanine aminotransferase (ALT) level, and pre-TACE aspartate aminotransferase (AST) level. Furthermore, in 50 patients who underwent TACE, the serum LAG-3 level was significantly decreased at 3 day after TACE.

Conclusion

Both pre-TACE and post-TACE serum LAG-3 levels could serve as powerful predictors for tumor response of TACE, and high pre-TACE serum LAG-3 level was an indicator for poor prognosis in HCC.

The Role of Soluble LAG3 and Soluble Immune Checkpoints Profile in Advanced Head and Neck Cancer: A Pilot Study

Unresectable recurrent and/or metastatic head and neck squamous cell carcinoma (R/M HNSCC) has a very poor prognosis. Soluble immune checkpoints (sICs) are circulating proteins that result from the alternative splicing of membrane proteins and can modulate the immune response to cancer cells. The aim of our pilot study was to determine the possible role of a comprehensive evaluation of sICs in the classification of prognosis and response to treatment in patients with advanced disease. We evaluated several sICs (CD137, CTLA-4, PD-1, PD-L1, PD-L2, TIM3, LAG3, GITR, HVEM, BTLA, IDO, CD80, CD27, and CD28) from peripheral blood at baseline and investigated the association with clinical characteristics and outcomes. A high baseline soluble LAG3 (sLAG3 > 377 pg/mL) resulted in an association with poor PFS and OS (p = 0.047 and p = 0.003, respectively). Moreover, sLAG3 emerged as an independent prognostic factor using an MVA (p = 0.005). The evaluation of sICs, in particular sLAG3, may be relevant for identifying patients with worse prognoses, or resistance to treatments, and may lead to the development of novel targeted strategies.

How to Best Exploit Immunotherapeutics in Advanced Gastric Cancer: Between Biomarkers and Novel Cell-Based Approaches

Despite extensive research efforts, advanced gastric cancer still has a dismal prognosis with conventional treatment options. Immune checkpoint inhibitors have revolutionized the treatment landscape for many solid tumors. Amongst gastric cancer subtypes, tumors with microsatellite instability and Epstein Barr Virus positive tumors provide the strongest rationale for responding to immunotherapy. Various predictive biomarkers such as mismatch repair status, programmed death ligand 1 expression, tumor mutational burden, assessment of tumor infiltrating lymphocytes and circulating biomarkers have been evaluated. However, results have been inconsistent due to different methodologies and thresholds used. Clinical implementation therefore remains a challenge. The role of immune checkpoint inhibitors in gastric cancer is emerging with data from monotherapy in the heavily pre-treated population already available and studies in earlier disease settings with different combinatorial approaches in progress. Immune checkpoint inhibitor combinations with chemotherapy (CT), anti-angiogenics, tyrosine kinase inhibitors, anti-Her2 directed therapy, poly (ADP-ribose) polymerase inhibitors or dual checkpoint inhibitor strategies are being explored. Moreover, novel strategies including vaccines and CAR T cell therapy are also being trialed. Here we provide an update on predictive biomarkers for response to immunotherapy with an overview of their strengths and limitations. We discuss clinical trials that have been reported and trials in progress whilst providing an account of future steps needed to improve outcome in this lethal disease.

Soluble TIM3 and Its Ligands Galectin-9 and CEACAM1 Are in Disequilibrium During Alcohol-Related Liver Disease and Promote Impairment of Anti-bacterial Immunity

BACKGROUND AND AIMS

Immunoregulatory checkpoint receptors (CR) contribute to the profound immunoparesis observed in alcohol-related liver disease (ALD) and in vitro neutralization of inhibitory-CRs TIM3/PD1 on anti-bacterial T-cells can rescue innate and adaptive anti-bacterial immunity. Recently described soluble-CR forms can modulate immunity in inflammatory conditions, but the contributions of soluble-TIM3 and soluble-PD1 and other soluble-CRs to immune derangements in ALD remain unclear.

METHODS

In Alcoholic Hepatitis (AH; n = 19), alcohol-related cirrhosis (ARC; n = 53) and healthy control (HC; n = 27) subjects, we measured by Luminex technology (i) plasma levels of 16 soluble-CRs, 12 pro/anti-inflammatory cytokines and markers of gut bacterial translocation; (ii) pre-hepatic, post-hepatic and non-hepatic soluble-CR plasma levels in ARC patients undergoing TIPS; (iii) soluble-CRs production from ethanol-treated immunocompetent precision cut human liver slices (PCLS); (iv) whole-blood soluble-CR expression upon bacterial challenge. By FACS, we assessed the relationship between soluble-TIM3 and membrane-TIM3 and rescue of immunity in bacterial-challenged PBMCs.

RESULTS

Soluble-TIM3 was the dominant plasma soluble-CR in ALD vs. HC (p = 0.00002) and multivariate analysis identified it as the main driver of differences between groups. Soluble-CRs were strongly correlated with pro-inflammatory cytokines, gut bacterial translocation markers and clinical indices of disease severity. Ethanol exposure or bacterial challenge did not induce soluble-TIM3 production from PCLS nor from whole-blood. Bacterial challenge prompted membrane-TIM3 hyperexpression on PBMCs from ALD patient's vs. HC (p < 0.002) and was inversely correlated with plasma soluble-TIM3 levels in matched patients. TIM3 ligands soluble-Galectin-9 and soluble-CEACAM1 were elevated in ALD plasma (AH > ARC; p < 0.002). In vitro neutralization of Galectin-9 and soluble-CEACAM1 improved the defective anti-bacterial and anti-inflammatory cytokine production from E. coli-challenged PBMCs in ALD patients.

CONCLUSIONS

Alcohol-related liver disease patients exhibit supra-physiological plasma levels of soluble-TIM3, particularly those with greater disease severity. This is also associated with increased levels of soluble TIM3-ligands and membrane-TIM3 expression on immune cells. Soluble-TIM3 can block the TIM3-ligand synapse and improve anti-bacterial immunity; however, the increased levels of soluble TIM3-binding ligands in patients with ALD negate any potential immunostimulatory effects. We believe that anti-TIM3 neutralizing antibodies currently in Phase I clinical trials or soluble-TIM3 should be investigated further for their ability to enhance anti-bacterial immunity. These agents could potentially represent an innovative immune-based supportive approach to rescue anti-bacterial defenses in ALD patients.

Checkpoint Molecules in Rheumatology-or the Benefits of Being Exhausted

PURPOSE OF REVIEW

This review will focus on the most common co-inhibitory molecules, emphasizing the importance of these in relation to rheumatic disease.

RECENT FINDINGS

Checkpoint molecules are pivotal in determining the outcome of antigen activation. Checkpoint molecules consist of co-stimulatory and co-inhibitory molecules, where the first activates and the latter inhibits the antigen presentation process. Studies show that increased activity of co-inhibitory molecules is associated with a good prognosis in rheumatic diseases. Opposite, when cancer patients are treated with antibodies blocking the inhibitory pathways, autoimmune diseases, including arthritis, develop as immune-related adverse events (IrAE). This emphasizes the importance of these pathways in autoimmune disease. Co-inhibitory molecules are becoming increasingly interesting as future treatment targets in rheumatic conditions. Treatments with antibodies blocking these pathways result in IrAE, often manifesting as autoimmune rheumatic diseases. Therefore, a need to get acquainted with these molecules is growing so we can cope with future challenges in rheumatic diseases.

Research Progress Concerning Dual Blockade of Lymphocyte-Activation Gene 3 and Programmed Death-1/Programmed Death-1 Ligand-1 Blockade in Cancer Immunotherapy: Preclinical and Clinical Evidence of This Potentially More Effective Immunotherapy Strategy

Although various immunotherapies have exerted promising effects on cancer treatment, many patients with cancer continue to exhibit poor responses. Because of its negative regulatory effects on T cells and its biological functions related to immune and inflammatory responses, there has been considerable emphasis on a protein-coding gene named lymphocyte-activation gene 3 (LAG3). Recently, evidence demonstrated marked synergy in its targeted therapy with programmed death-1 and programmed death-1 ligand-1 (PD-1/PD-L1) blockade, and a variety of LAG3 targeted agents are in clinical trials, indicating the important role of LAG3 in immunotherapy. This mini-review discusses preclinical and clinical studies investigating PD-1 pathway blockade in combination with LAG3 inhibition as a potentially more effective immunotherapy strategy for further development in the clinic. This strategy might provide a new approach for the design of more effective and precise cancer immune checkpoint therapies.