Role of LAG-3 in regulatory T cells

Unlocking therapeutic potential: Targeting lymphocyte activation Gene-3 (LAG-3) with fibrinogen-like protein 1 (FGL1) in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) represents an autoimmune disorder that affects multiple systems. In the treatment of this condition, the focus primarily revolves around inflammation suppression and immunosuppression. Consequently, targeted therapy has emerged as a prevailing approach. Currently, the quest for highly sensitive and specifically effective targets has gained significant momentum in the context of SLE treatment. Lymphocyte activation gene-3 (LAG-3) stands out as a crucial inhibitory receptor that binds to pMHC-II, thereby effectively dampening autoimmune responses. Fibrinogen-like protein 1 (FGL1) serves as the principal immunosuppressive ligand for LAG-3, and their combined action demonstrates a potent immunosuppressive effect. This intricate mechanism paves the way for potential SLE treatment by targeting LAG-3 with FGL1. This work provides a comprehensive summary of LAG-3's role in the pathogenesis of SLE and elucidates the feasibility of leveraging FGL1 as a therapeutic approach for SLE management. It introduces a novel therapeutic target and opens up new avenues of therapeutic consideration in the clinical context of SLE treatment.

Novel insights into immune cells modulation of tumor resistance

Tumor resistance poses a significant challenge to effective cancer treatment, making it imperative to explore new therapeutic strategies. Recent studies have highlighted the profound involvement of immune cells in the development of tumor resistance. Within the tumor microenvironment, macrophages undergo polarization into the M2 phenotype, thus promoting the emergence of drug-resistant tumors. Neutrophils contribute to tumor resistance by forming extracellular traps. While T cells and natural killer (NK) cells exert their impact through direct cytotoxicity against tumor cells. Additionally, dendritic cells (DCs) have been implicated in preventing tumor drug resistance by stimulating T cell activation. In this review, we provide a comprehensive summary of the current knowledge regarding immune cell-mediated modulation of tumor resistance at the molecular level, with a particular focus on macrophages, neutrophils, DCs, T cells, and NK cells. The targeting of immune cell modulation exhibits considerable potential for addressing drug resistance, and an in-depth understanding of the molecular interactions between immune cells and tumor cells holds promise for the development of innovative therapies. Furthermore, we explore the clinical implications of these immune cells in the treatment of drug-resistant tumors. This review emphasizes the exploration of novel approaches that harness the functional capabilities of immune cells to effectively overcome drug-resistant tumors.

Exploring the molecular landscape of lymphocyte activation gene-3: A literature review

Molecular structure and cellular distribution of lymphocyte activation gene-3 (LAG-3) have been studied extensively since 1990. However, several unresolved questions remain. It is well-established that LAG-3 plays a significant role in maintaining immune homeostasis. The presence of deficiencies in LAG-3 has been observed to be linked with autoimmune disorders, whereas the excessive expression of LAG-3 within the tumor microenvironment hinders immune responses, particularly those mediated by lymphocytes, thereby facilitating immune evasion. Consequently, investigations into these 2 aspects have become a prominent focus in both fundamental and clinical research. The objective of this review is to examine the functions and molecular characteristics of LAG-3, as well as its current clinical applications in the context of tumor immune escape and autoimmune disease. The ultimate aim is to explore and propose novel immune therapy approach.

Indirect suppression of CD4 T cell activation through LAG-3-mediated trans-endocytosis of MHC class II

Blockade of immune checkpoint receptors has shown outstanding efficacy for tumor immunotherapy. Promising treatment with anti-lymphocyte-activation gene-3 (LAG-3) has already been recognized as the next efficacious treatment, but there is still limited understanding of the mechanism of LAG-3-mediated immune suppression. Here, utilizing high-resolution molecular imaging, we find a mechanism of CD4 T cell suppression via LAG-3, in which LAG-3-bound major histocompatibility complex (MHC) class II molecules on antigen-presenting cells (APCs) gather at the central region of an immunological synapse and are trans-endocytosed by T cell receptor-driven internalization motility toward CD4 and CD8 T cells expressing LAG-3. Downregulation of MHC class II molecules on APCs thus results in the attenuation of their antigen-presentation function and impairment of CD4 T cell activation. From these data, anti-LAG-3 treatment is suggested to have potency to directly block the inhibitory signaling via LAG-3 and simultaneously reduce MHC class II expression on APCs by LAG-3-mediated trans-endocytosis for recovery from T cell exhaustion.

Immune checkpoint pathways in glioblastoma: a diverse and evolving landscape

Immune checkpoint (IC) inhibition in glioblastoma (GBM) has not shown promising results in the last decade compared to other solid tumors. Several factors contributing to the lack of immunotherapy response include the profound immunosuppressive nature of GBM, highly redundant signaling pathways underlying immune checkpoints, and the negative immunogenic impact of current standard of care on the tumor microenvironment. In this review, we will discuss various ICs in the context of GBM, their interplay with the tumor immune microenvironment, relevant pre-clinical and clinical studies, and the impact of current treatment modalities on GBM IC blockade therapy. Understanding the molecular mechanisms that drive ICs, and how they contribute to an immunosuppressive tumor microenvironment is critical in advancing IC inhibition therapy in GBM. Furthermore, revisiting current treatment modalities and their impact on the immune landscape is instrumental in designing future combinatorial therapies that may overcome treatment resistance.

Advances in immunotherapy for breast cancer and feline mammary carcinoma: From molecular basis to novel therapeutic targets

The role of inflammation in cancer is a topic that has been investigated for many years. As established, inflammation emerges as a defining characteristic of cancer, presenting itself as a compelling target for therapeutic interventions in the realm of oncology. Controlling the tumor microenvironment (TME) has gained paramount significance, modifying not only the effectiveness of immunotherapy but also modulating the outcomes and prognoses of standard chemotherapy and other anticancer treatments. Immunotherapy has surfaced as a central focus within the domain of tumor treatments, using immune checkpoint inhibitors as cancer therapy. Immune checkpoints and their influence on the tumor microenvironment dynamic are presently under investigation, aiming to ascertain their viability as therapeutic interventions across several cancer types. Cancer presents a significant challenge in humans and cats, where female breast cancer ranks as the most prevalent malignancy and feline mammary carcinoma stands as the third most frequent. This review seeks to summarize the data about the immune checkpoints cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), lymphocyte activation gene-3 (LAG-3), programmed cell death protein-1 (PD-1), V-domain Ig suppressor of T cell activation (VISTA), and T-cell immunoglobulin and mucin domain 3 (TIM-3) respective ongoing investigations as prospective targets for therapy for human breast cancer, while also outlining findings from studies reported on feline mammary carcinoma (FMC), strengthening the rationale for employing FMC as a representative model in the exploration of human breast cancer.

Progesterone receptor impairs immune respond and down-regulates sensitivity to anti-LAG3 in breast cancer

BACKGROUND

Progesterone receptor (PR) serves as a crucial prognostic and predictive marker in breast cancer. Nonetheless, the interplay between PR and the tumor immune microenvironment remains inadequately understood. This investigation employs bioinformatics analyses, mouse models, and clinical specimens to elucidate the impact of PR on immune microenvironment and identify potential targets for immunotherapy, furnishing valuable guidance for clinical practice.

METHODS

Analysis of immune infiltration score by Xcell between PR-positive and PR-negative breast cancer tumors. Construction of overexpression mouse progesterone receptor (mPgr) EMT-6 cell was to explore the tumor immune microenvironment. Furthermore, anti- Lymphocyte-activation gene 3 (LAG3) therapy aimed to investigate whether PR could influence the effectiveness of immune treatments.

RESULTS

Overexpression mPgr inhibited tumor growth in vitro, but promoted tumor growth in Balb/c mouse. Flow cytometry showed that the proportion and cytotoxicity of CD8+T cells in tumor of overexpressing mPgr group were significantly reduced. The significant reduction in overexpressing mPgr group was found in the proportions of LAG3+CD8+ T cells and LAG3+ Treg T cells. Anti-LAG3 treatment resulted in reduced tumor growth in EV group mouse rather than in overexpressing mPgr group. Patents derived tumor fragment (PDTF) also showed higher anti-tumor ability of CD3+T cell in patents' tumor with PR <20% after anti-human LAG3 treatment in vitro.

CONCLUSIONS

The mPgr promotes tumor growth by downregulating the infiltration and function of cytotoxic cell. LAG3 may be a target of ER-positive breast cancer immunotherapy. The high expression of PR hinders the sensitivity to anti-LAG3 treatment.

Surface Immune Checkpoints as Potential Biomarkers in Physiological Pregnancy and Recurrent Pregnancy Loss

Due to the genetic diversity between the mother and the fetus, heightened control over the immune system during pregnancy is crucial. Immunological parameters determined by clinicians in women with idiopathic recurrent spontaneous abortion (RSA) include the quantity and activity of Natural Killer (NK) and Natural Killer T (NKT) cells, the quantity of regulatory T lymphocytes, and the ratio of pro-inflammatory cytokines, which indicate imbalances in Th1 and Th2 cell response. The processes are controlled by immune checkpoint proteins (ICPs) expressed on the surface of immune cells. We aim to investigate differences in the expression of ICPs on T cells, T regulatory lymphocytes, NK cells, and NKT cells in peripheral blood samples collected from RSA women, pregnant women, and healthy multiparous women. We aim to discover new insights into the role of ICPs involved in recurrent pregnancy loss. Peripheral blood mononuclear cells (PBMCs) were isolated by gradient centrifugation from blood samples obtained from 10 multiparous women, 20 pregnant women (11-14th week of pregnancy), and 20 RSA women, at maximum of 72 h after miscarriage. The PBMCs were stained for flow cytometry analysis. Standard flow cytometry immunophenotyping of PBMCs was performed using antibodies against classical lymphocyte markers, including CD3, CD4, CD8, CD56, CD25, and CD127. Additionally, ICPs were investigated using antibodies against Programmed Death Protein-1 (PD-1, CD279), T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3, CD366), V-domain Ig suppressor of T cell activation (VISTA), T cell immunoglobulin and ITIM domain (TIGIT), and Lymphocyte activation gene 3 (LAG-3). We observed differences in the surface expression of ICPs in the analyzed subpopulations of lymphocytes between early pregnancy and RSA, after miscarriage, and in women. We noted diminished expression of PD-1 on T lymphocytes (p = 0.0046), T helper cells (CD3CD4 positive cells, p = 0.0165), T cytotoxic cells (CD3CD8 positive cells, p = 0.0046), T regulatory lymphocytes (CD3CD4CD25CD127 low positive cells, p = 0.0106), and NKT cells (CD3CD56/CD16 positive cells, p = 0.0438), as well as LAG-3 on lymphocytes T (p = 0.0225) T helper, p = 0.0426), T cytotoxic cells (p = 0.0458) and Treg (p = 0.0293), and cells from RSA women. Impaired expression of TIM-3 (p = 0.0226) and VISTA (p = 0.0039) on CD8 cytotoxic T and NK (TIM3 p = 0.0482; VISTA p = 0.0118) cells was shown, with an accompanying increased expression of TIGIT (p = 0.0211) on NKT cells. The changes in the expression of surface immune checkpoints indicate their involvement in the regulation of pregnancy. The data might be utilized to develop specific therapies for RSA women based on the modulation of ICP expression.

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.

Inhibitory co-receptor Lag3 supports Foxp3+ regulatory T cell function by restraining Myc-dependent metabolic programming

Lymphocyte activation gene 3 (Lag3) is an inhibitory co-receptor expressed on activated T cells and has been proposed to regulate regulatory T (Treg) cell function. However, its precise modality and mechanisms remain elusive. We generated Treg cell-specific Lag3-mutant mouse models and found that Lag3 was essential for Treg cell control of autoimmunity. RNA sequencing analysis revealed that Lag3 mutation altered genes associated with metabolic processes, especially Myc target genes. Myc expression in Lag3-mutant Treg cells was increased to the level seen in conventional T helper (Th)1-type effector cells and directly correlated with their metabolic profiles and in vivo suppressive functions. The phosphatidylinositol 3-kinase (PI3K)-Akt-Rictor pathway was activated in Lag3-mutant Treg cells, and inhibiting PI3K, Rictor, or lactate dehydrogenase A (Ldha), a key Myc target enzyme converting pyruvate to lactate, was sufficient to restore normal metabolism and suppressive function in Lag3-mutant Treg cells. These findings indicate that Lag3 supports Treg cell suppression partly by tuning Myc-dependent metabolic programming.

Revamping Hepatocellular Carcinoma Immunotherapy: The Advent of Microbial Neoantigen Vaccines

Immunotherapy has revolutionized the treatment paradigm for hepatocellular carcinoma (HCC). However, its efficacy varies significantly with each patient's genetic composition and the complex interactions with their microbiome, both of which are pivotal in shaping anti-tumor immunity. The emergence of microbial neoantigens, a novel class of tumor vaccines, heralds a transformative shift in HCC therapy. This review explores the untapped potential of microbial neoantigens as innovative tumor vaccines, poised to redefine current HCC treatment modalities. For instance, neoantigens derived from the microbiome have demonstrated the capacity to enhance anti-tumor immunity in colorectal cancer, suggesting similar applications in HCC. By harnessing these unique neoantigens, we propose a framework for a personalized immunotherapeutic response, aiming to deliver a more precise and potent treatment strategy for HCC. Leveraging these neoantigens could significantly advance personalized medicine, potentially revolutionizing patient outcomes in HCC therapy.

Neurotrophic factor Neuritin modulates T cell electrical and metabolic state for the balance of tolerance and immunity

The adaptive T cell response is accompanied by continuous rewiring of the T cell's electric and metabolic state. Ion channels and nutrient transporters integrate bioelectric and biochemical signals from the environment, setting cellular electric and metabolic states. Divergent electric and metabolic states contribute to T cell immunity or tolerance. Here, we report that neuritin (Nrn1) contributes to tolerance development by modulating regulatory and effector T cell function. Nrn1 expression in regulatory T cells promotes its expansion and suppression function, while expression in the T effector cell dampens its inflammatory response. Nrn1 deficiency causes dysregulation of ion channel and nutrient transporter expression in Treg and effector T cells, resulting in divergent metabolic outcomes and impacting autoimmune disease progression and recovery. These findings identify a novel immune function of the neurotrophic factor Nrn1 in regulating the T cell metabolic state in a cell context-dependent manner and modulating the outcome of an immune response.

Expression and Prognostic Significance of LAG-3, TIGIT, VISTA, and IDO1 in Endometrial Serous Carcinoma

Endometrial serous carcinoma (ESC) is an uncommon, aggressive type of endometrial cancer. While immune checkpoint blockade has emerged as a promising treatment option for endometrial carcinomas, research on the expression of immune checkpoints that could serve as prospective immunotherapy targets in ESC is limited. We examined the prevalence and prognostic value of lymphocyte-activation gene 3 (LAG-3), T-cell immunoglobulin and ITIM domain (TIGIT), V-domain immunoglobulin (Ig) suppressor of T-cell activation (VISTA), and indoleamine 2,3-dioxygenase 1 (IOD1) in 94 cases of ESC and correlated their expression with CD8+ and FOXP3+ tumor-infiltrating lymphocytes (TILs). We observed a positive correlation among LAG-3, TIGIT, and VISTA expressed on immune cells, and among these markers and CD8+ and FOXP3+ TIL densities. In Kaplan-Meier survival analysis, tumors with high levels of LAG-3 and TIGIT expression had better progression-free survival (PFS) and overall survival (OS) than those with lower levels of expression (LAG-3: PFS, P = .03, OS, P = .04; TIGIT: PFS, P = .01, OS, P = .009). In multivariate analysis, only high TIGIT expression was of independent prognostic value for better OS. VISTA expression in immune or tumor cells, and IDO1 expression in tumor cells, did not show a significant association with survival. Our data indicate that LAG-3, TIGIT, and VISTA immune checkpoints have roles in the microenvironment of ESC, and their expression patterns highlight the complex interactions among the different components of this system. High levels of these markers, together with high CD8+ TIL, suggest the potential immunogenicity of a subset of these tumors. Further studies are needed to elucidate the roles of various immune components in the ESC microenvironment and their association with intrinsic tumor properties.

Immunotherapy for head and neck cancer: Fundamentals and therapeutic development

Squamous cell carcinoma of the head and neck (SCCHN) has been treated by multidisciplinary therapy consisting of surgery, radiotherapy, and cancer chemotherapy, but the recent advent of immunotherapy has produced significant changes in treatment systems and the results of these therapies. Immunotherapy has greatly improved the outcome of recurrent metastatic SCCHN, and the development of new treatment methods based on immunotherapy is now being applied not only to recurrent metastatic cases but also to locally advanced cases. To understand and practice cancer immunotherapy, it is important to understand the immune environment surrounding cancer, and the changes to which it is subject. Currently, the anti-PD-1 antibody drugs nivolumab and pembrolizumab are the only immunotherapies with proven efficacy in head and neck cancer. However, anti-PD-L1 and anti-CTLA-4 antibody drugs have also been shown to be useful in other types of cancer and are being incorporated into clinical practice. In head and neck cancer, numerous clinical trials have aimed to improve efficacy and safety by combining immunotherapy with other drug therapies and treatment modalities. Combinations of immunotherapy with cancer drugs with different mechanisms of action (cytotoxic agents, molecular-targeted agents, immune checkpoint inhibitors), as well as with radiation therapy and surgery are being investigated, and have the potential to significantly change medical care for these patients. The application of cancer immunotherapy not only to daily clinical practice but also to further therapeutic development requires a clear and complete understanding of the fundamentals of cancer immunotherapy, and knowledge of the numerous clinical studies conducted, both past and present. The results of these trials are numerous, both positive and negative, and a comprehensive understanding of this wide range of completed and ongoing clinical trials is critical to a systematic and comprehensive understanding of their scope and lessons learnt. In this article, after outlining the concepts of ``cancer immune cycle,'' ``cancer immune editing,'' and ``tumor microenvironment'' to provide an understanding of the basics of cancer immunity, we summarize the basics and clinical trial data on representative immune checkpoint inhibitors used in various cancer types, as well as recent therapeutic developments in cancer immunotherapy and the current status of these new treatments.

Multi-Layered Mechanisms of Immunological Tolerance at the Maternal-Fetal Interface

Pregnancy represents an immunological paradox where the maternal immune system must tolerate the semi-allogeneic fetus expressing paternally-derived Ags. Accumulating evidence over decades has revealed that successful pregnancy requires the active development of robust immune tolerance mechanisms. This review outlines the multi-layered processes that establish fetomaternal tolerance, including the physical barrier of the placenta, restricted chemokine-mediated leukocyte trafficking, lack of sufficient alloantigen presentation, the presence of immunosuppressive regulatory T cells and tolerogenic decidual natural killer cells, expression of immune checkpoint molecules, specific glycosylation patterns conferring immune evasion, and unique metabolic/hormonal modulations. Interestingly, many of the strategies that enable fetal tolerance parallel those employed by cancer cells to promote angiogenesis, invasion, and immune escape. As such, further elucidating the mechanistic underpinnings of fetal-maternal tolerance may reciprocally provide insights into developing novel cancer immunotherapies as well as understanding the pathogenesis of gestational complications linked to dysregulated tolerance processes.

Distinct Localization, Transcriptional Profiles, and Functionality in Early Life Tonsil Regulatory T Cells

CD4+ regulatory T cells (Tregs) are key orchestrators of the immune system, fostering the establishment of protective immunity while preventing deleterious responses. Infancy and childhood are crucial periods of rapid immunologic development, but how Tregs mediate immune responses at these earliest timepoints of human life is poorly understood. In this study, we compare blood and tissue (tonsil) Tregs across pediatric and adult subjects to investigate age-related differences in Treg biology. We observed increased FOXP3 expression and proportions of Tregs in tonsil compared with paired blood samples in children. Within tonsil, early life Tregs accumulated in extrafollicular regions with cellular interactions biased toward CD8+ T cells. Tonsil Tregs in both children and adults expressed transcriptional profiles enriched for lineage defining signatures and canonical functionality compared with blood, suggesting tissue as the primary site of Treg activity. Early life tonsil Tregs transcriptional profiles were further defined by pathways associated with activation, proliferation, and polyfunctionality. Observed differences in pediatric tonsil Treg transcriptional signatures were associated with phenotypic differences, high proliferative capacity, and robust production of IL-10 compared with adult Tregs. These results identify tissue as a major driver of Treg identity, provide new insights into developmental differences in Treg biology across the human lifespan, and demonstrate unique functional properties of early life Tregs.

IL-10-modulated dendritic cells from birch pollen- and hazelnut-allergic patients facilitate Treg-mediated allergen-specific and cross-reactive tolerance

BACKGROUND

Approximately 70% of individuals allergic to birch pollen (Bet v 1.01 [Bet]) develop a secondary food allergy (e.g., hazelnut: Cor a 1.04 [Cor]), due to allergen cross-reactivity. However, standard immunotherapy for type I allergies often does not improve the food allergy sufficiently. We analyzed the allergen-specific and cross-reactive suppressive capacity of primary human regulatory T cells (Treg) induced by autologous IL-10-modulated dendritic cells (IL-10 DC) in vitro and in vivo.

METHODS

CD4+ T cells of patients with birch pollen and associated hazelnut allergies were differentiated into Bet-specific or non-specific induced Treg (iTreg). After Bet- or Cor-specific restimulation the phenotype, proliferation, and suppressive capacity of iTreg subsets were analyzed. iTreg function was further investigated in humanized mouse models of airway and intestinal allergy, generated by engraftment of peripheral blood mononuclear cells from allergic donors into immunodeficient animals.

RESULTS

After IL-10 DC priming and allergen-specific restimulation (Bet or Cor), non-specific control iTreg remained anergic, whereas Bet-specific iTreg proliferated extensively and exhibited a regulatory phenotype (enhanced expression of CTLA-4, PD-1, TNFR2, IL-10). Accordingly, activated Bet-specific iTreg displayed a high capacity to suppress Bet- and Cor-induced responder Th2 cell responses in vitro, indicating induction of both allergen-specific (birch) and cross-reactive tolerance (hazelnut). In vivo, the beneficial effect of Bet-specific iTreg was verified in humanized mouse models of allergic airway and intestinal inflammation, resulting in reduced allergen-induced clinical symptoms, and immune responses.

CONCLUSION

Human IL-10 DC-induced iTreg facilitate allergen-specific and cross-reactive tolerance. Therefore, they are potential candidates for regulatory cell therapy in allergic and autoimmune diseases.

Current Trends and Innovative Approaches in Cancer Immunotherapy

Immunotherapy is one of the most promising therapeutic approaches in the field of cancer treatment. As a tumor progresses, tumor cells employ an array of immune-regulatory mechanisms to suppress immune responses within the tumor microenvironment. Using our understanding of these mechanisms, cancer immunotherapy has been developed to enhance the immune system's effectiveness in treating cancer. Numerous cancer immunotherapies are currently in clinical use, yet many others are either in different stages of development or undergoing clinical studies. In this paper, we briefly discuss the features and current status of cancer immunotherapies. This includes the application of monoclonal antibodies, immune checkpoint inhibitors, adoptive cell therapy, cytokine therapy, cancer vaccines, and gene therapy, all of which have gained significant recognition in clinical practice. Additionally, we discuss limitations that may hinder successful clinical utilization and promising strategies, such as combining immunotherapy with nanotechnology.

Advancements in Personalized CAR-T Therapy: Comprehensive Overview of Biomarkers and Therapeutic Targets in Hematological Malignancies

Chimeric antigen receptor T-cell (CAR-T) therapy is a novel anticancer therapy using autologous or allogeneic T-cells. To date, six CAR-T therapies for specific B-cell acute lymphoblastic leukemia (B-ALL), non-Hodgkin lymphomas (NHL), and multiple myeloma (MM) have been approved by the Food and Drug Administration (FDA). Significant barriers to the effectiveness of CAR-T therapy include cytokine release syndrome (CRS), neurotoxicity in the case of Allogeneic Stem Cell Transplantation (Allo-SCT) graft-versus-host-disease (GVHD), antigen escape, modest antitumor activity, restricted trafficking, limited persistence, the immunosuppressive microenvironment, and senescence and exhaustion of CAR-Ts. Furthermore, cancer drug resistance remains a major problem in clinical practice. CAR-T therapy, in combination with checkpoint blockades and bispecific T-cell engagers (BiTEs) or other drugs, appears to be an appealing anticancer strategy. Many of these agents have shown impressive results, combining efficacy with tolerability. Biomarkers like extracellular vesicles (EVs), cell-free DNA (cfDNA), circulating tumor (ctDNA) and miRNAs may play an important role in toxicity, relapse assessment, and efficacy prediction, and can be implicated in clinical applications of CAR-T therapy and in establishing safe and efficacious personalized medicine. However, further research is required to fully comprehend the particular side effects of immunomodulation, to ascertain the best order and combination of this medication with conventional chemotherapy and targeted therapies, and to find reliable predictive biomarkers.

Expression of immune checkpoint molecules TIGIT and TIM-3 by tumor-infiltrating lymphocytes predicts poor outcome in sinonasal mucosal melanoma

BACKGROUND

Sinonasal mucosal melanoma (SNMM) is a rare but aggressive tumor with a poor prognosis. The co-inhibitory receptors T cell immunoglobulin and mucinodomain containing-3 (TIM-3), lymphocyte activation gene-3 (LAG-3) and T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) are promising new targets in anti-cancer immunotherapy. The expression profiles of these immune checkpoint molecules (ICMs) and potential prognostic implications have not been characterized in SNMM yet.

METHODS

Immunohistochemical staining for TIGIT, LAG-3 and TIM-3 was performed on tumor tissue samples from 27 patients with primary SNMM. Associations between ICM expression and demographic parameters, AJCC tumor stage, overall survival, and recurrence-free survival were retrospectively analyzed.

RESULTS

SNMM patients with low numbers of TIGIT+ and TIM-3+ tumor infiltrating lymphocytes (TILs) in the primary tumor survived significantly longer than patients with a high degree of TIGIT+ and TIM-3+ TILs. High infiltration with TIM-3+ or TIGIT+ lymphocytes was associated with the higher T4 stage and decreased 5-year survival.

CONCLUSION

We identified high densities of TIM-3+ and TIGIT+ TILs as strong negative prognostic biomarkers in SNMM. This suggests that TIM-3 and TIGIT contribute to immunosuppression in SNMM and provides a rationale for novel treatment strategies based on this next generation of immune checkpoint inhibitors. Prospective studies with larger case numbers are warranted to confirm our findings and their implications for immunotherapy.

Cutting Edge: LAG3 Dimerization Is Required for TCR/CD3 Interaction and Inhibition of Antitumor Immunity

Lymphocyte activation gene 3 (LAG3) is an inhibitory receptor that plays a critical role in controlling T cell tolerance and autoimmunity and is a major immunotherapeutic target. LAG3 is expressed on the cell surface as a homodimer but the functional relevance of this is unknown. In this study, we show that the association between the TCR/CD3 complex and a murine LAG3 mutant that cannot dimerize is perturbed in CD8+ T cells. We also show that LAG3 dimerization is required for optimal inhibitory function in a B16-gp100 tumor model. Finally, we demonstrate that a therapeutic LAG3 Ab, C9B7W, which does not block LAG3 interaction with its cognate ligand MHC class II, disrupts LAG3 dimerization and its association with the TCR/CD3 complex. These studies highlight the functional importance of LAG3 dimerization and offer additional approaches to therapeutically target LAG3.

Rosmarinic acid activates the Ras/Raf/MEK/ERK signaling pathway to regulate CD8+ T cells and autophagy to clear Chlamydia trachomatis in reproductive tract-infected mice

Chlamydia trachomatis (CT) is the leading cause of bacterial sexually transmitted diseases worldwide, which can cause diseases such as pelvic inflammatory disease, and cervical and fallopian tube inflammation, and poses a threat to human health. Rosmarinic acid (RosA) is an active ingredient of natural products with anti-inflammatory and immunomodulatory effects. This study aimed to investigate the role of RosA in inhibiting autophagy-regulated immune cells-CD8+ T cells via the Ras/Raf/MEK/ERK signaling pathway in a CT-infected mouse model. Mice were inoculated with CT infection solution vaginally, and the mechanistic basis of RosA treatment was established using H&E staining, flow cytometry, immunofluorescence, transmission electron microscopy, and western blot. The key factors involved in RosA treatment were further validated using the MEK inhibitor cobimetinib. Experimental results showed that both RosA and the reference drug azithromycin could attenuate the pathological damage to the endometrium caused by CT infection; flow cytometry showed that peripheral blood CD8+ T cells increased after CT infection and decreased after treatment with RosA and the positive drug azithromycin (positive control); immunofluorescence showed that endometrial CD8 and LC3 increased after CT infection and decreased after RosA and positive drug treatment; the results of transmission electron microscopy showed that RosA and the positive drug azithromycin inhibited the accumulation of autophagosomes; western bolt experiments confirmed the activation of autophagy proteins LC3Ⅱ/Ⅰ, ATG5, Beclin-1, and p62 after CT infection, as well as the inhibition of Ras/Raf/MEK/ERK signaling. RosA and azithromycin inhibition of autophagy proteins activates Ras/Raf/MEK/ERK signaling. In addition, the MEK inhibitor cobimetinib attenuated RosA's protective effect on endometrium by further activating CD8+ T cells on a CT-induced basis, while transmission electron microscopy, immunofluorescence, and western blots showed that cobimetinib blocked ERK signals activation and further induced phagocytosis on a CT-induced basis. These data indicated that RosA can activate the Ras/Raf/MEK/ERK signaling pathway to inhibit autophagy, and RosA could also regulate the activation of immune cells-CD8+T cells to protect the reproductive tract of CT-infected mice.

Regulatory T Cell Dysfunction in Autoimmune Diseases

Regulatory T cells (Tregs), a suppressive subpopulation of T cells, are potent mediators of peripheral tolerance, responsible for immune homeostasis. Many autoimmune diseases exhibit disruptions in Treg function or quantity, resulting in an imbalance between protective and pathogenic immune cells. Selective expansion or manipulation of Tregs is a promising therapeutic approach for autoimmune diseases. However, the extensive diversity of Treg subpopulations and the multiple approaches used for Treg identification leads to high complexity, making it difficult to develop a successful treatment capable of modulating Tregs. In this review, we describe the suppressive mechanisms, subpopulations, classification, and identification methodology for Tregs, and their role in the pathogenesis of autoimmune diseases.

Many Faces of Regulatory T Cells: Heterogeneity or Plasticity?

Regulatory T cells (Tregs) are essential for maintaining the immune balance in normal and pathological conditions. In autoimmune diseases and transplantation, they restrain the loss of self-tolerance and promote engraftment, whereas in cancer, an increase in Treg numbers is mostly associated with tumor growth and poor prognosis. Numerous markers and their combinations have been used to identify Treg subsets, demonstrating the phenotypic diversity of Tregs. The complexity of Treg identification can be hampered by the unstable expression of some markers, the decrease in the expression of a specific marker over time or the emergence of a new marker. It remains unclear whether such phenotypic shifts are due to new conditions or whether the observed changes are due to initially different populations. In the first case, cellular plasticity is observed, whereas in the second, cellular heterogeneity is observed. The difference between these terms in relation to Tregs is rather blurred. Considering the promising perspectives of Tregs in regenerative cell-based therapy, the existing confusing data on Treg phenotypes require further investigation and analysis. In our review, we introduce criteria that allow us to distinguish between the heterogeneity and plasticity of Tregs normally and pathologically, taking a closer look at their diversity and drawing the line between two terms.

Neoadjuvant nivolumab with or without relatlimab in resectable non-small-cell lung cancer: a randomized phase 2 trial

Antibodies targeting the immune checkpoint molecules PD-1, PD-L1 and CTLA-4, administered alone or in combination with chemotherapy, are the standard of care in most patients with metastatic non-small-cell lung cancers. When given before curative surgery, tumor responses and improved event-free survival are achieved. New antibody combinations may be more efficacious and tolerable. In an ongoing, open-label phase 2 study, 60 biomarker-unselected, treatment-naive patients with resectable non-small-cell lung cancer were randomized to receive two preoperative doses of nivolumab (anti-PD-1) with or without relatlimab (anti-LAG-3) antibody therapy. The primary study endpoint was the feasibility of surgery within 43 days, which was met by all patients. Curative resection was achieved in 95% of patients. Secondary endpoints included pathological and radiographic response rates, pathologically complete resection rates, disease-free and overall survival rates, and safety. Major pathological (≤10% viable tumor cells) and objective radiographic responses were achieved in 27% and 10% (nivolumab) and in 30% and 27% (nivolumab and relatlimab) of patients, respectively. In 100% (nivolumab) and 90% (nivolumab and relatlimab) of patients, tumors and lymph nodes were pathologically completely resected. With 12 months median duration of follow-up, disease-free survival and overall survival rates at 12 months were 89% and 93% (nivolumab), and 93% and 100% (nivolumab and relatlimab). Both treatments were safe with grade ≥3 treatment-emergent adverse events reported in 10% and 13% of patients per study arm. Exploratory analyses provided insights into biological processes triggered by preoperative immunotherapy. This study establishes the feasibility and safety of dual targeting of PD-1 and LAG-3 before lung cancer surgery.ClinicalTrials.gov Indentifier: NCT04205552 .

Defining Human Regulatory T Cells beyond FOXP3: The Need to Combine Phenotype with Function

Regulatory T cells (Tregs) are essential to maintain immune homeostasis by promoting self-tolerance. Reduced Treg numbers or functionality can lead to a loss of tolerance, increasing the risk of developing autoimmune diseases. An overwhelming variety of human Tregs has been described, based on either specific phenotype, tissue compartment, or pathological condition, yet the bulk of the literature only addresses CD25-positive and CD127-negative cells, coined by naturally occurring Tregs (nTregs), most of which express the transcription factor Forkhead box protein 3 (FOXP3). While the discovery of FOXP3 was seminal to understanding the origin and biology of nTregs, there is evidence in humans that not all T cells expressing FOXP3 are regulatory, and that not all Tregs express FOXP3. Namely, the activation of human T cells induces the transient expression of FOXP3, irrespective of whether they are regulatory or inflammatory effectors, while some induced T cells that may be broadly defined as Tregs (e.g., Tr1 cells) typically lack demethylation and do not express FOXP3. Furthermore, it is unknown whether and how many nTregs exist without FOXP3 expression. Several other candidate regulatory molecules, such as GITR, Lag-3, GARP, GPA33, Helios, and Neuropilin, have been identified but subsequently discarded as Treg-specific markers. Multiparametric analyses have uncovered a plethora of Treg phenotypes, and neither single markers nor combinations thereof can define all and only Tregs. To date, only the functional capacity to inhibit immune responses defines a Treg and distinguishes Tregs from inflammatory T cells (Teffs) in humans. This review revisits current knowledge of the Treg universe with respect to their heterogeneity in phenotype and function. We propose that it is unavoidable to characterize human Tregs by their phenotype in combination with their function, since phenotype alone does not unambiguously define Tregs. There is an unmet need to align the expression of specific markers or combinations thereof with a particular suppressive function to coin functional Treg entities and categorize Treg diversity.

Prostaglandin E2 in the Tumor Microenvironment, a Convoluted Affair Mediated by EP Receptors 2 and 4

The involvement of the prostaglandin E2 (PGE2) system in cancer progression has long been recognized. PGE2 functions as an autocrine and paracrine signaling molecule with pleiotropic effects in the human body. High levels of intratumoral PGE2 and overexpression of the key metabolic enzymes of PGE2 have been observed and suggested to contribute to tumor progression. This has been claimed for different types of solid tumors, including, but not limited to, lung, breast, and colon cancer. PGE2 has direct effects on tumor cells and angiogenesis that are known to promote tumor development. However, one of the main mechanisms behind PGE2 driving cancerogenesis is currently thought to be anchored in suppressed antitumor immunity, thus providing possible therapeutic targets to be used in cancer immunotherapies. EP2 and EP4, two receptors for PGE2, are emerging as being the most relevant for this purpose. This review aims to summarize the known roles of PGE2 in the immune system and its functions within the tumor microenvironment. SIGNIFICANCE STATEMENT: Prostaglandin E2 (PGE2) has long been known to be a signaling molecule in cancer. Its presence in tumors has been repeatedly associated with disease progression. Elucidation of its effects on immunological components of the tumor microenvironment has highlighted the potential of PGE2 receptor antagonists in cancer treatment, particularly in combination with immune checkpoint inhibitor therapeutics. Adjuvant treatment could increase the response rates and the efficacy of immune-based therapies.

Exploring the therapeutic potential of regulatory T cell in rheumatoid arthritis: Insights into subsets, markers, and signaling pathways

Rheumatoid arthritis (RA) is a complex autoimmune inflammatory rheumatic disease characterized by an imbalance between immunological reactivity and immune tolerance. Regulatory T cells (Tregs), which play a crucial role in controlling ongoing autoimmunity and maintaining peripheral tolerance, have shown great potential for the treatment of autoimmune inflammatory rheumatic diseases such as RA. This review aims to provide an updated summary of the latest insights into Treg-targeting techniques in RA. We focus on current therapeutic strategies for targeting Tregs based on discussing their subsets, surface markers, suppressive function, and signaling pathways in RA.

The Role of Regulatory T Cells and Their Therapeutic Potential in Hypertensive Disease of Pregnancy: A Literature Review

Hypertensive disorders of pregnancy (HDP), including preeclampsia (PE) and gestational hypertension (GH), are major causes of maternal and foetal morbidity and mortality. This review elucidates the role of regulatory T cells (Tregs) in the immunological aspects of HDP and explores their therapeutic potential. Tregs, which play a critical role in maintaining immune homeostasis, are crucial in pregnancy to prevent immune-mediated rejection of the foetus. The review highlights that Tregs contribute to immunological adaptation in normal pregnancy, ensuring foetal acceptance. In contrast, HDP is associated with Treg dysfunction, which is marked by decreased numbers and impaired regulatory capacity, leading to inadequate immune tolerance and abnormal placental development. This dysfunction is particularly evident in PE, in which Tregs fail to adequately modulate the maternal immune response against foetal antigens, contributing to the pathophysiology of the disorder. Therapeutic interventions aiming to modulate Treg activity represent a promising avenue for HDP management. Studies in animal models and limited clinical trials suggest that enhancing Treg functionality could mitigate HDP symptoms and improve pregnancy outcomes. However, given the multifactorial nature of HDP and the intricate regulatory mechanisms of Tregs, the review explores the complexities of translating in vitro and animal model findings into effective clinical therapies. In conclusion, while the precise role of Tregs in HDP is still being unravelled, their central role in immune regulation during pregnancy is indisputable. Further research is needed to fully understand the mechanisms by which Tregs contribute to HDP and to develop targeted therapies that can safely and effectively harness their regulatory potential for treating hypertensive diseases of pregnancy.

The dual role of regulatory T cells in hepatitis B virus infection and related hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a major contributor to cancer-related deaths worldwide. Hepatitis B virus (HBV) infection is a major etiologic factor leading to HCC. While there have been significant advancements in controlling HBV replication, achieving a complete cure for HBV-related HCC (HBV-HCC) remains an intricate challenge. HBV persistence is attributed to a myriad of mechanisms, encompassing both innate and adaptive immune responses. Regulatory T cells (Tregs) are pivotal in upholding immune tolerance and modulating excessive immune activation. During HBV infection, Tregs mediate specific T cell suppression, thereby contributing to both persistent infection and the mitigation of liver inflammatory responses. Studies have demonstrated an augmented expression of circulating and intrahepatic Tregs in HBV-HCC, which correlates with impaired CD8+ T cell function. Consequently, Tregs play a dual role in the context of HBV infection and the progression of HBV-HCC. In this comprehensive review, we discuss pertinent studies concerning Tregs in HBV infection, HBV-related cirrhosis and HCC. Furthermore, we summarize Treg responses to antiviral therapy and provide Treg-targeted therapies specific to HBV and HCC.

LAG-3- and CXCR5-expressing CD4 T cells display progenitor-like properties during chronic visceral leishmaniasis

Maintenance of CD4 T cells during chronic infections is vital for limiting pathogen burden and disease recrudescence. Although inhibitory receptor expression by CD4 T cells is commonly associated with immune suppression and exhaustion, such cell-intrinsic mechanisms that control activation are also associated with cell survival. Using a mouse model of visceral leishmaniasis (VL), we discovered a subset of lymphocyte activation gene 3 (LAG-3)-expressing CD4 T cells that co-express CXCR5. Although LAG3+CXCR5+ CD4 T cells are present in naive mice, they expand during VL. These cells express gene signatures associated with self-renewal capacity, suggesting progenitor-like properties. When transferred into Rag1-/- mice, these LAG3+CXCR5+ CD4 T cells differentiated into multiple effector types upon Leishmania donovani infection. The transcriptional repressor B cell lymphoma-6 was partially required for their maintenance. Altogether, we propose that the LAG3+CXCR5+ CD4 T cell subset could play a role in maintaining CD4 T cell responses during persistent infections.

Targeting tumor-infiltrating tregs for improved antitumor responses

Immunotherapies have revolutionized the landscape of cancer treatment. Regulatory T cells (Tregs), as crucial components of the tumor immune environment, has great therapeutic potential. However, nonspecific inhibition of Tregs in therapies may not lead to enhanced antitumor responses, but could also trigger autoimmune reactions in patients, resulting in intolerable treatment side effects. Hence, the precision targeting and inhibition of tumor-infiltrating Tregs is of paramount importance. In this overview, we summarize the characteristics and subpopulations of Tregs within tumor microenvironment and their inhibitory mechanisms in antitumor responses. Furthermore, we discuss the current major strategies targeting regulatory T cells, weighing their advantages and limitations, and summarize representative clinical trials targeting Tregs in cancer treatment. We believe that developing therapies that specifically target and suppress tumor-infiltrating Tregs holds great promise for advancing immune-based therapies.

Development of LAG-3/FGL1 blocking peptide and combination with radiotherapy for cancer immunotherapy

Aside from antibodies, peptides show great potential as immune checkpoint inhibitors (ICIs) due to several advantages, such as better tumor penetration and lower cost. Lymphocyte-activation gene 3 (LAG-3) is an immune checkpoint which can induce T cell dysfunction through interaction with its soluble ligand fibrinogen like protein-1 (FGL1). Here, we found that LAG-3 expression was higher than programmed cell death protein 1 (PD-1) in multiple human cancers by TCGA databases, and successfully identified a LAG-3 binding peptide LFP-6 by phage display bio-panning, which specifically blocks the interaction of LAG-3/FGL1 but not LAG-3/MHC-II. Subsequently, d-amino acids were introduced to substitute the N- and C-terminus of LFP-6 to obtain the proteolysis-resistant peptide LFP-D1, which restores T cell function in vitro and inhibits tumor growth in vivo. Further, a bispecific peptide LFOP targeting both PD-1/PD-L1 and LAG-3/FGL1 was designed by conjugating LFP-D1 with PD-1/PD-L1 blocking peptide OPBP-1(8-12), which activates T cell with enhanced proliferation and IFN-γ production. More importantly, LFOP combined with radiotherapy significantly improve the T cell infiltration in tumor and elevate systemic antitumor immune response. In conclusion, we developed a novel peptide blocking LAG-3/FGL1 which can restore T cell function, and the bispecific peptide synergizes with radiotherapy to further enhance the antitumor immune response.

Upregulation of CD8+ regulatory T cells following liver-directed AAV gene therapy

Liver-directed AAV gene therapy represents a unique treatment modality for a host of diseases. This is due, in part, to the induction of tolerance to transgene products. Despite the plethora of recognized regulatory cells in the body, there is currently a lack of literature supporting the induction of non-CD4+ regulatory cells following hepatic AAV gene transfer. In this work, we show that CD8+ regulatory T cells are up-regulated in PBMCs of mice following capsid only and therapeutic transgene AAV administration. Further, we demonstrate that hepatic AAV gene transfer results in a significant increase in CD8+ regulatory T cells following experimental autoimmune encephalomyelitis induction. Notably, this response occurred only in therapeutic vector treated animals, not capsid only controls. Understanding the role these cells play in treatment efficacy will result in the development of improved AAV vectors that take advantage of the full gamut of regulatory cells within the body.

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

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

The paradoxical role of cytokines and chemokines at the tumor microenvironment: a comprehensive review

Tumor progression and eradication have long piqued the scientific community's interest. Recent discoveries about the role of chemokines and cytokines in these processes have fueled renewed interest in related research. These roles are frequently viewed as contentious due to their ability to both suppress and promote cancer progression. As a result, this review critically appraised existing literature to discuss the unique roles of cytokines and chemokines in the tumor microenvironment, as well as the existing challenges and future opportunities for exploiting these roles to develop novel and targeted treatments. While these modulatory molecules play an important role in tumor suppression via enhanced cancer-cell identification by cytotoxic effector cells and directly recruiting immunological effector cells and stromal cells in the TME, we observed that they also promote tumor proliferation. Many cytokines, including GM-CSF, IL-7, IL-12, IL-15, IL-18, and IL-21, have entered clinical trials for people with advanced cancer, while the FDA has approved interferon-alpha and IL-2. Nonetheless, low efficacy and dose-limiting toxicity limit these agents' full potential. Conversely, Chemokines have tremendous potential for increasing cancer immune-cell penetration of the tumor microenvironment and promoting beneficial immunological interactions. When chemokines are combined with cytokines, they activate lymphocytes, producing IL-2, CD80, and IL-12, all of which have a strong anticancer effect. This phenomenon opens the door to the development of effective anticancer combination therapies, such as therapies that can reverse cancer escape, and chemotaxis of immunosuppressive cells like Tregs, MDSCs, and TAMs.

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.

Leveraging Lymphatic System Targeting in Systemic Lupus Erythematosus for Improved Clinical Outcomes

The role of advanced drug delivery strategies in drug repositioning and minimizing drug attrition rates, when applied early in drug discovery, is poised to increase the translational impact of various therapeutic strategies in disease prevention and treatment. In this context, drug delivery to the lymphatic system is gaining prominence not only to improve the systemic bioavailability of various pharmaceutical drugs but also to target certain specific diseases associated with the lymphatic system. Although the role of the lymphatic system in lupus is known, very little is done to target drugs to yield improved clinical benefits. In this review, we discuss recent advances in drug delivery strategies to treat lupus, the various routes of drug administration leading to improved lymph node bioavailability, and the available technologies applied in other areas that can be adapted to lupus treatment. Moreover, this review also presents some recent findings that demonstrate the promise of lymphatic targeting in a preclinical setting, offering renewed hope for certain pharmaceutical drugs that are limited by efficacy in their conventional dosage forms. These findings underscore the potential and feasibility of such lymphatic drug-targeting approaches to enhance therapeutic efficacy in lupus and minimize off-target effects of the pharmaceutical drugs. SIGNIFICANCE STATEMENT: The World Health Organization estimates that there are currently 5 million humans living with some form of lupus. With limited success in lupus drug discovery, turning to effective delivery strategies with existing drug molecules, as well as those in the early stage of discovery, could lead to better clinical outcomes. After all, effective delivery strategies have been proven to improve treatment outcomes.

Synergistic combination therapy using cowpea mosaic virus intratumoral immunotherapy and Lag-3 checkpoint blockade

Immune checkpoint therapy (ICT) for cancer can yield dramatic clinical responses; however, these may only be observed in a minority of patients. These responses can be further limited by subsequent disease recurrence and resistance. Combination immunotherapy strategies are being developed to overcome these limitations. We have previously reported enhanced efficacy of combined intratumoral cowpea mosaic virus immunotherapy (CPMV IIT) and ICT approaches. Lymphocyte-activation gene-3 (LAG-3) is a next-generation inhibitory immune checkpoint with broad expression across multiple immune cell subsets. Its expression increases on activated T cells and contributes to T cell exhaustion. We observed heightened efficacy of a combined CPMV IIT and anti-LAG-3 treatment in a mouse model of melanoma. Further, LAG-3 expression was found to be increased within the TME following intratumoral CPMV administration. The integration of CPMV IIT with LAG-3 inhibition holds significant potential to improve treatment outcomes by concurrently inducing a comprehensive anti-tumor immune response, enhancing local immune activation, and mitigating T cell exhaustion.

The B7:CD28 family and friends: Unraveling coinhibitory interactions

Immune responses must be tightly regulated to ensure both optimal protective immunity and tolerance. Costimulatory pathways within the B7:CD28 family provide essential signals for optimal T cell activation and clonal expansion. They provide crucial inhibitory signals that maintain immune homeostasis, control resolution of inflammation, regulate host defense, and promote tolerance to prevent autoimmunity. Tumors and chronic pathogens can exploit these pathways to evade eradication by the immune system. Advances in understanding B7:CD28 pathways have ushered in a new era of immunotherapy with effective drugs to treat cancer, autoimmune diseases, infectious diseases, and transplant rejection. Here, we discuss current understanding of the mechanisms underlying the coinhibitory functions of CTLA-4, PD-1, PD-L1:B7-1 and PD-L2:RGMb interactions and less studied B7 family members, including HHLA2, VISTA, BTNL2, and BTN3A1, as well as their overlapping and unique roles in regulating immune responses, and the therapeutic potential of these insights.

Bibliometric analysis of evolutionary trajectory and prospective directions of LAG-3 in cancer

Objectives

Perform a bibliometric analysis on the role of LAG-3 in the domain of cancer, elucidate the prevailing areas of research, and visually depict the evolutionary trajectory and prospective directions of LAG-3 research over the past twenty-three decades.

Materials and methods

Between 2000 and 2023, a comprehensive review of scholarly articles pertaining to LAG-3 research in the context of cancer was carried out using the Web of Science Core Collection (WoSCC) database. Bibliometric analysis can be conducted by taking advantage of VOSviewer (version 1.6.16) and CiteSpace (version 6.2.R4). Create a network diagram to visually represent various authors, countries, and organizations while assessing the publishing years, journals, references, and keywords.

Results

In conclusion, 1841 records were identified and published in 587 publications. These records were authored by 12,849 individuals affiliated with 2491 institutes across 74 countries. There has been a substantial surge in publications subsequent to 2013. The USA, China, and Germany gave the majority of records, amounting to 69.69%. American institutions actively engage in collaboration with institutions located in other countries. Triebel, F., Vignali, Dario A. A., Workman, Creg J. Drake, Charles G., and Elkord, Eyad are highly regarded authors in their respective fields. However, it is worth noting that Triebel exhibits limited collaboration with other writers. The examination of the role of LAG-3 in cancer and its potential for use in clinical settings is a discernible trend, as seen by keyword analysis.

Conclusion

The scientific interest in and attention towards LAG-3 has experienced a significant rise since 2013. The United States is leading the way, with China following closely behind. Promoting collaboration among writers, nations, and institutions with varied backgrounds is imperative. The discipline of immunotherapy is currently seeing ongoing progress. A thorough investigation of the distinctive cis ligand TCR-CD3 complex of LAG-3 and its signal transduction mechanism is necessary. Additionally, it is worthwhile to explore novel combinations of LAG-3 therapy.

Immune checkpoint inhibitors associated cardiovascular immune-related adverse events

Immune checkpoint inhibitors (ICIs) are specialized monoclonal antibodies (mAbs) that target immune checkpoints and their ligands, counteracting cancer cell-induced T-cell suppression. Approved ICIs like cytotoxic T-lymphocyte antigen-4 (CTLA-4), programmed death-1 (PD-1), its ligand PD-L1, and lymphocyte activation gene-3 (LAG-3) have improved cancer patient outcomes by enhancing anti-tumor responses. However, some patients are unresponsive, and others experience immune-related adverse events (irAEs), affecting organs like the lung, liver, intestine, skin and now the cardiovascular system. These cardiac irAEs include conditions like myocarditis, atherosclerosis, pericarditis, arrhythmias, and cardiomyopathy. Ongoing clinical trials investigate promising alternative co-inhibitory receptor targets, including T cell immunoglobulin and mucin domain-containing protein 3 (Tim-3) and T cell immunoreceptor with immunoglobulin and ITIM domain (TIGIT). This review delves into the mechanisms of approved ICIs (CTLA-4, PD-1, PD-L1, and LAG-3) and upcoming options like Tim-3 and TIGIT. It explores the use of ICIs in cancer treatment, supported by both preclinical and clinical data. Additionally, it examines the mechanisms behind cardiac toxic irAEs, focusing on ICI-associated myocarditis and atherosclerosis. These insights are vital as ICIs continue to revolutionize cancer therapy, offering hope to patients, while also necessitating careful monitoring and management of potential side effects, including emerging cardiac complications.

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.

Clinicopathological comparison between PTCL-TBX21 and PTCL-GATA3 in Japanese patients

AIM

Peripheral T-cell lymphoma not otherwise specified (PTCL-NOS) is a heterogeneous disease that can be classified into the PTCL-TBX21 and PTCL-GATA3 subtypes.

METHODS

In this study, we compared the clinicopathological features of PTCL-NOS in a Japanese cohort, classified using an IHC algorithm.

RESULTS

One hundred patients with PTCL-NOS were categorized as having PTCL-TBX21 (n = 55), PTCL-GATA3 (n = 24), or PTCL-unclassified (n = 21). When comparing PTCL-TBX21 and PTCL-GATA3, PTCL-TBX21 showed significantly lower CD4 positivity (p = 0.047), lower counts of high endothelial venules (p = 0.032), and a tendency for a better response to initial treatment (p = 0.088). Gene expression analysis using the nCounter system showed higher expression of tumor immunity-related genes, such as PD-L1, LAG3, and IDO1, in PTCL-TBX21 than in PTCL-GATA3. PTCL-GATA3 had significantly worse overall survival (OS) than those with PTCL-TBX21 (p = 0.047), although a similar tendency was observed for progression-free survival (PFS) (p = 0.064). PTCL-GATA3 was a prognostic factor for OS in univariate analysis (HR 2.02; 95% CI, 1.09-3.77; p = 0.027), although multivariate analysis did not show significance (HR 2.07; 95% CI, 0.93-4.61; p = 0.074). In the PFS analysis, PTCL-GATA3 was an independent prognostic factor by univariate analysis (HR 1.96; 95% CI, 1.08-3.56; p = 0.027) and multivariate analysis (HR 2.34; 95% CI, 1.07-5.11; p = 0.032).

CONCLUSION

The classification of PTCL-NOS into PTCL-TBX21 and PTCL-GATA3 is useful for predicting the prognosis of Japanese patients and stratifying the administration of tumor immune checkpoint inhibitors in clinical practice.

Sialic acid-modified der p 2 allergen exerts immunomodulatory effects on human PBMCs

Background

House dust mite extract-based allergen immunotherapy (AIT) to treat house dust mite allergy is substantially effective but still presents some safety and efficacy concerns that warrant improvement. Several major allergen-based approaches to increase safety and efficacy of AIT have been proposed. One of them is the use of the group 2 allergen, Der p 2.

Objective

We sought to investigate the immunomodulatory effects of sialic acid-modified major allergen recombinant Der p 2 (sia-rDer p 2) on PBMCs from healthy volunteers.

Methods

We activated PBMCs with anti-CD3/CD28 antibodies and incubated them at 37°C for 6 days in the presence or absence of either native rDer p 2 or α2-3 sialic acid-modified rDer p 2 (sia-rDer p 2). We assessed the changes in CD4+ T-cell activation and proliferation by flow cytometry and changes in T-lymphocyte cytokine production in cell culture supernatant by ELISA.

Results

We observed that PBMCs treated with sia-rDer p 2 presented with a markedly decreased expression of CD69 and an increased abundance of LAG-3+ lymphocytes compared with cells treated with rDer p 2. Moreover, PBMCs treated with sia-rDer p 2 showed a reduced production of IL-4, IL-13, and IL-5 and displayed a higher IL-10/IL-5 ratio compared with rDer p 2-treated PBMCs.

Conclusions

We demonstrate that sia-rDer p 2 might be a safer option than native rDer p 2 for Der p 2-specific AIT. This is most relevant in the early phase of AIT that is often characterized by heightened TH2 responses, because sia-rDer p 2 does not enhance the production of TH2 cytokines.

Anti-PD-L1-Based Bispecific Antibodies Targeting Co-Inhibitory and Co-Stimulatory Molecules for Cancer Immunotherapy

Targeting PD-L1 via monospecific antibodies has shown durable clinical benefits and long-term remissions where patients exhibit no clinical cancer signs for many years after treatment. However, the durable clinical benefits and long-term remissions by anti-PD-L1 monotherapy have been limited to a small fraction of patients with certain cancer types. Targeting PD-L1 via bispecific antibodies (referred to as anti-PD-L1-based bsAbs) which can simultaneously bind to both co-inhibitory and co-stimulatory molecules may increase the durable antitumor responses in patients who would not benefit from PD-L1 monotherapy. A growing number of anti-PD-L1-based bsAbs have been developed to fight against this deadly disease. This review summarizes recent advances of anti-PD-L1-based bsAbs for cancer immunotherapy in patents and literatures, and discusses their anti-tumor efficacies in vitro and in vivo. Over 50 anti-PD-L1-based bsAbs targeting both co-inhibitory and co-stimulatory molecules have been investigated in biological testing or in clinical trials since 2017. At least eleven proteins, such as CTLA-4, LAG-3, PD-1, PD-L2, TIM-3, TIGIT, CD28, CD27, OX40, CD137, and ICOS, are involved in these investigations. Twenty-two anti-PD-L1-based bsAbs are being evaluated to treat various advanced cancers in clinical trials, wherein the indications include NSCLC, SNSCLC, SCLC, PDA, MBNHL, SCCHN, UC, EC, TNBC, CC, and some other malignancies. The released data from clinical trials indicated that most of the anti-PD-L1-based bsAbs were well-tolerated and showed promising antitumor efficacy in patients with advanced solid tumors. However, since the approved and investigational bsAbs have shown much more significant adverse reactions compared to PD-L1 monospecific antibodies, anti-PD-L1-based bsAbs may be further optimized via molecular structure modification to avoid or reduce these adverse reactions.

Beyond FOXP3: a 20-year journey unravelling human regulatory T-cell heterogeneity

The initial idea of a distinct group of T-cells responsible for suppressing immune responses was first postulated half a century ago. However, it is only in the last three decades that we have identified what we now term regulatory T-cells (Tregs), and subsequently elucidated and crystallized our understanding of them. Human Tregs have emerged as essential to immune tolerance and the prevention of autoimmune diseases and are typically contemporaneously characterized by their CD3+CD4+CD25high CD127lowFOXP3+ phenotype. It is important to note that FOXP3+ Tregs exhibit substantial diversity in their origin, phenotypic characteristics, and function. Identifying reliable markers is crucial to the accurate identification, quantification, and assessment of Tregs in health and disease, as well as the enrichment and expansion of viable cells for adoptive cell therapy. In our comprehensive review, we address the contributions of various markers identified in the last two decades since the master transcriptional factor FOXP3 was identified in establishing and enriching purity, lineage stability, tissue homing and suppressive proficiency in CD4+ Tregs. Additionally, our review delves into recent breakthroughs in innovative Treg-based therapies, underscoring the significance of distinct markers in their therapeutic utilization. Understanding Treg subsets holds the key to effectively harnessing human Tregs for immunotherapeutic approaches.

Advances in new targets for immunotherapy of small cell lung cancer

Small cell lung cancer (SCLC) is one of the highly aggressive malignancies characterized by rapid growth and early metastasis, but treatment options are limited. For SCLC, carboplatin or cisplatin in combination with etoposide chemotherapy has been considered the only standard of care, but the standard first-line treatment only results in 10-month survival. The majority of patients relapse within a few weeks to months after treatment, despite the relatively sensitive response to chemotherapy. Over the past decade, immunotherapy has made significant progress in the treatment of SCLC patients. However, there have been limited improvements in survival rates for SCLC patients with the current immune checkpoint inhibitors PD-1/PD-L1 and CTLA-4. In the face of high recurrence rates, small beneficiary populations, and low survival benefits, the exploration of new targets for key molecules and signals in SCLC and the development of drugs with novel mechanisms may provide fresh hope for immunotherapy in SCLC. Therefore, the aim of this review was to explore four new targets, DLL3, TIGIT, LAG-3, and GD2, which may play a role in the immunotherapy of SCLC to find useful clues and strategies to improve the outcome for SCLC patients.

Targeted Mevalonate Pathway and Autophagy in Antitumor Immunotherapy

Tumors of the digestive system are currently one of the leading causes of cancer-related death worldwide. Despite considerable progress in tumor immunotherapy, the prognosis for most patients remains poor. In the tumor microenvironment (TME), tumor cells attain immune escape through immune editing and acquire immune tolerance. The mevalonate pathway and autophagy play important roles in cancer biology, antitumor immunity, and regulation of the TME. In addition, there is metabolic crosstalk between the two pathways. However, their role in promoting immune tolerance in digestive system tumors has not previously been summarized. Therefore, this review focuses on the cancer biology of the mevalonate pathway and autophagy, the regulation of the TME, metabolic crosstalk between the pathways, and the evaluation of their efficacy as targeted inhibitors in clinical tumor immunotherapy.

Soluble Forms of Immune Checkpoints and Their Ligands as Potential Biomarkers in the Diagnosis of Recurrent Pregnancy Loss-A Preliminary Study

Immune checkpoints (ICPs) serve as regulatory switches on immune-competent cells. Soluble ICPs consist of fragments derived from ICP molecules typically located on cell membranes. Research has demonstrated that they perform similar functions to their membrane-bound counterparts but are directly present in the bloodstream. Effective control of the maternal immune system is vital for a successful pregnancy due to genetic differences between the mother and fetus. Abnormalities in the immune response are widely acknowledged as the primary cause of spontaneous abortions. In our research, we introduce a novel approach to understanding the immune-mediated mechanisms underlying recurrent miscarriages and explore new possibilities for diagnosing and preventing pregnancy loss. The female participants in the study were divided into three groups: RSA (recurrent spontaneous abortion), pregnant, and non-pregnant women. The analysis of soluble forms of immune checkpoints and their ligands in the serum of the study groups was conducted using the Luminex method Statistically significant differences in the concentrations of (ICPs) were observed between physiological pregnancies and the RSA group. Among patients with RSA, we noted reduced concentrations of sGalectin-9, sTIM-3, and sCD155, along with elevated concentrations of LAG-3, sCD80, and sCD86 ICPs, in comparison to physiological pregnancies. Our study indicates that sGalectin-9, TIM-3, sLAG-3, sCD80, sCD86, sVISTA, sNectin-2, and sCD155 could potentially serve as biological markers of a healthy, physiological pregnancy. These findings suggest that changes in the concentrations of soluble immune checkpoints may have the potential to act as markers for early pregnancy loss.