CTLA-4 is a second receptor for the B cell activation antigen B7

Cell-Int: a cell-cell interaction assay to identify native membrane protein interactions

Intercellular protein-protein interactions (PPIs) have pivotal roles in biological functions and diseases. Membrane proteins are therefore a major class of drug targets. However, studying such intercellular PPIs is challenging because of the properties of membrane proteins. Current methods commonly use purified or modified proteins that are not physiologically relevant and hence might mischaracterize interactions occurring in vivo. Here, we describe Cell-Int: a cell interaction assay for studying plasma membrane PPIs. The interaction signal is measured through conjugate formation between two populations of cells each expressing either a ligand or a receptor. In these settings, membrane proteins are in their native environment thus being physiologically relevant. Cell-Int has been applied to the study of diverse protein partners, and enables to investigate the inhibitory potential of blocking antibodies, as well as the retargeting of fusion proteins for therapeutic development. The assay was also validated for screening applications and could serve as a platform for identifying new protein interactors.

Emerging innovative treatment strategies for advanced clear cell renal cell carcinoma

Dramatic advances in biological discoveries, since the 1990s, have continued to reshape the treatment paradigm of metastatic renal cell carcinoma (RCC). Von Hippel Lindau (VHL) gene alterations are associated with pro-angiogenic activity and are central to the pathogenesis of clear cell RCC (ccRCC), the most predominant histologic subtype of RCC. Antiangiogenic strategies revolving around this VHL/HIF/VEGF axis have been shown to improve survival in metastatic ccRCC. The discovery of immune checkpoints and agents that target their inhibition introduced a new treatment paradigm for patients with RCC. While initially approved as monotherapy, studies investigating immune checkpoint inhibitor combinations have led to their approval as the new standard of care, providing durable responses and unprecedented improvements in clinical outcome. Despite these advances, the projected 14 390 deaths in 2024 from RCC underscore the need to continue efforts in expanding and optimizing treatment options for patients with metastatic RCC. This article reviews key findings that have transformed the way we understand and treat metastatic RCC, in addition to highlighting novel treatment strategies that are currently under development.

Context-restricted PD-(L)1 checkpoint agonism by CTLA4-Ig therapies inhibits T cell activity

T cell surface CTLA4 sequesters the costimulatory ligands CD80 and CD86 on antigen-presenting cells (APCs) to prevent autoimmunity. Therapeutic immunosuppression by recombinant CTLA4-immunoglobulin (Ig) fusion proteins, including abatacept, is also attributed to CD80/CD86 blockade. Recent studies show that CTLA4-Ig binding to APC surface cis-CD80:PD-L1 complexes can release the inhibitory ligand PD-L1, but whether this contributes to T cell inhibition remains unclear. Here, we show that PD-L1 liberation by CTLA4-Ig is strictly limited, both in extent and context, relative to PD-L1-competing anti-CD80 antibodies. At APC surface CD80:PD-L1 ratios exceeding 2:1, CTLA4-Ig therapies fail to release PD-L1 regardless of their CD80 affinity. Additionally, introducing flexibility into CTLA4-Ig by modifying its rigid homodimer interface produces biologics that retain bivalent CD80 binding without dissociating cis-bound PD-L1. These findings demonstrate that CTLA4-Ig therapies liberate PD-L1 through a CD80 reorientation mechanism that imposes a strict context dependence to their PD-1 checkpoint agonism and resultant T cell inhibition.

Combination anti-PD-1 and anti-CTLA-4 therapy generates waves of clonal responses that include progenitor-exhausted CD8+ T cells

Combination checkpoint blockade with anti-PD-1 and anti-CTLA-4 antibodies has shown promising efficacy in melanoma. However, the underlying mechanism in humans remains unclear. Here, we perform paired single-cell RNA and T cell receptor (TCR) sequencing across time in 36 patients with stage IV melanoma treated with anti-PD-1, anti-CTLA-4, or combination therapy. We develop the algorithm Cyclone to track temporal clonal dynamics and underlying cell states. Checkpoint blockade induces waves of clonal T cell responses that peak at distinct time points. Combination therapy results in greater magnitude of clonal responses at 6 and 9 weeks compared to single-agent therapies, including melanoma-specific CD8+ T cells and exhausted CD8+ T cell (TEX) clones. Focused analyses of TEX identify that anti-CTLA-4 induces robust expansion and proliferation of progenitor TEX, which synergizes with anti-PD-1 to reinvigorate TEX during combination therapy. These next generation immune profiling approaches can guide the selection of drugs, schedule, and dosing for novel combination strategies.

Immune checkpoint inhibitors in infectious disease

Following success in cancer immunotherapy, immune checkpoint blockade is emerging as an exciting potential treatment for some infectious diseases, specifically two chronic viral infections, HIV and hepatitis B. Here, we will discuss the function of immune checkpoints, their role in infectious disease pathology, and the ability of immune checkpoint blockade to reinvigorate the immune response. We focus on blockade of programmed cell death 1 (PD-1) to induce durable immune-mediated control of HIV, given that anti-PD-1 can restore function to exhausted HIV-specific T cells and also reverse HIV latency, a long-lived form of viral infection. We highlight several key studies and future directions of research in relation to anti-PD-1 and HIV persistence from our group, including the impact of immune checkpoint blockade on the establishment (AIDS, 2018, 32, 1491), maintenance (PLoS Pathog, 2016, 12, e1005761; J Infect Dis, 2017, 215, 911; Cell Rep Med, 2022, 3, 100766) and reversal of HIV latency (Nat Commun, 2019, 10, 814; J Immunol, 2020, 204, 1242), enhancement of HIV-specific T cell function (J Immunol, 2022, 208, 54; iScience, 2023, 26, 108165), and investigating the effects of anti-PD-1 and anti-CTLA-4 in vivo in people with HIV on ART with cancer (Sci Transl Med, 2022, 14, eabl3836; AIDS, 2021, 35, 1631; Clin Infect Dis, 2021, 73, e1973). Our future work will focus on the impact of anti-PD-1 in vivo in people with HIV on ART without cancer and potential combinations of anti-PD-1 with other interventions, including therapeutic vaccines or antibodies and less toxic immune checkpoint blockers.

Breaking tolerance: the autoimmune aspect of atherosclerosis

Atherosclerotic cardiovascular disease (ASCVD) is a chronic inflammatory disease of the arterial walls and is characterized by the accumulation of lipoproteins that are insufficiently cleared by phagocytes. Following the initiation of atherosclerosis, the pathological progression is accelerated by engagement of the adaptive immune system. Atherosclerosis triggers the breakdown of tolerance to self-components. This loss of tolerance is reflected in defective expression of immune checkpoint molecules, dysfunctional antigen presentation, and aberrations in T cell populations - most notably in regulatory T (Treg) cells - and in the production of autoantibodies. The breakdown of tolerance to self-proteins that is observed in ASCVD may be linked to the conversion of Treg cells to 'exTreg' cells because many Treg cells in ASCVD express T cell receptors that are specific for self-epitopes. Alternatively, or in addition, breakdown of tolerance may trigger the activation of naive T cells, resulting in the clonal expansion of T cell populations with pro-inflammatory and cytotoxic effector phenotypes. In this Perspective, we review the evidence that atherosclerosis is associated with a breakdown of tolerance to self-antigens, discuss possible immunological mechanisms and identify knowledge gaps to map out future research. Rational approaches aimed at re-establishing immune tolerance may become game changers in treating ASCVD and in preventing its downstream sequelae, which include heart attacks and strokes.

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.

Phase I studies of davoceticept (ALPN-202), a PD-L1-dependent CD28 co-stimulator and dual PD-L1/CTLA-4 inhibitor, as monotherapy and in combination with pembrolizumab in advanced solid tumors (NEON-1 and NEON-2)

BACKGROUND

Davoceticept (ALPN-202) is an Fc fusion of a CD80 variant immunoglobulin domain designed to mediate programmed death-ligand 1 (PD-L1)-dependent CD28 co-stimulation while inhibiting the PD-L1 and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) checkpoints. The safety and efficacy of davoceticept monotherapy and davoceticept and pembrolizumab combination therapy in adult patients with advanced solid tumors were explored in NEON-1 and NEON-2, respectively.

METHODS

In NEON-1 (n=58), davoceticept 0.001-10 mg/kg was administered intravenous either once weekly (Q1W) or once every 3 weeks (Q3W). In NEON-2 (n=29), davoceticept was administered intravenously at 2 dose levels (0.1 or 0.3 mg/kg) Q1W or Q3W with pembrolizumab (400 mg once every 6 weeks). In both studies, primary endpoints included incidence of dose-limiting toxicities (DLT); type, incidence, and severity of adverse events (AEs) and laboratory abnormalities; and seriousness of AEs. Secondary endpoints included antitumor efficacy assessed using RECIST v1.1, pharmacokinetics, anti-drug antibodies, and pharmacodynamic biomarkers.

RESULTS

The incidence of treatment-related AEs (TRAEs) and immune-related adverse events (irAEs) was 67% (39/58) and 36% (21/58) with davoceticept monotherapy, and 62% (18/29) and 31% (9/29) with davoceticept and pembrolizumab combination, respectively. The incidence of ≥grade (Gr)3 TRAEs and ≥Gr3 irAEs was 12% (7/58) and 5% (3/58) with davoceticept monotherapy, and 24% (7/29) and 10% (3/29) with davoceticept and pembrolizumab combination, respectively. One DLT of Gr3 immune-related gastritis occurred during davoceticept monotherapy 3 mg/kg Q3W. During davoceticept combination with pembrolizumab, two Gr5 cardiac DLTs occurred; one instance each of cardiogenic shock (0.3 mg/kg Q3W, choroidal melanoma metastatic to the liver) and immune-mediated myocarditis (0.1 mg/kg Q3W, microsatellite stable metastatic colorectal adenocarcinoma), prompting early termination of both studies. Across both studies, five patients with renal cell carcinoma (RCC) exhibited evidence of clinical benefit (two partial response, three stable disease).

CONCLUSIONS

Davoceticept was generally well tolerated as monotherapy at intravenous doses up to 10 mg/kg. Evidence of clinical activity was observed with davoceticept monotherapy and davoceticept in combination with pembrolizumab, notably in RCC. However, two fatal cardiac events occurred with the combination of low-dose davoceticept and pembrolizumab. Future clinical investigation with davoceticept should not consider combination with programmed death-1-inhibitor anticancer mechanisms, until its safety profile is more fully elucidated.

TRIAL REGISTRATION NUMBER

NEON-1 (NCT04186637) and NEON-2 (NCT04920383).

Immune Checkpoint Inhibitors for Pediatric Cancers: Is It Still a Stalemate?

The knowledge surrounding the application of immune checkpoint inhibitors (ICIs) in the treatment of pediatric cancers is continuously expanding and evolving. These therapies work by enhancing the body's natural immune response against tumors, which may have been suppressed by certain pathways. The effectiveness of ICIs in treating adult cancers has been widely acknowledged. However, the results of early phase I/II clinical trials that exclusively targeted the use of ICIs for treating different pediatric cancers have been underwhelming. The response rates to ICIs have generally been modest, except for cases of pediatric classic Hodgkin lymphoma. There seems to be a notable disparity in the immunogenicity of childhood cancers compared to adult cancers, potentially accounting for this phenomenon. On average, childhood cancers tend to have significantly fewer neoantigens. In recent times, there has been a renewed sense of optimism regarding the potential benefits of ICI therapies for specific groups of children with cancer. In initial research, individuals diagnosed with pediatric hypermutated and SMARCB1-deficient cancers have shown remarkable positive outcomes when treated with ICI therapies. This is likely due to the underlying biological factors that promote the expression of neoantigens and inflammation within the tumor. Ongoing trials are diligently assessing the effectiveness of ICIs for pediatric cancer patients in these specific subsets. This review aimed to analyze the safety and effectiveness of ICIs in pediatric patients with different types of highly advanced malignancies.

mTOR Deletion Alleviates CD4+ T-Cell Dysfunction in Sepsis through Reducing CTLA4 Accumulation Mediated by Rescuing Autophagy

Sepsis has been the leading cause of death in ICU patients. CD4+ T cells are the mainstay of the body's immune system, and the depletion of CD4+ T cells in sepsis is of great concern. Cytotoxic T lymphocyte-associated protein 4 (CTLA4) is a negative immunomodulator for T cell activation and degradation through the autophagy-lysosome pathway. Mammalian target of rapamycin (mTOR) is the most classical upstream regulator of autophagy. With a mouse model of sepsis through cecal ligation and puncture (CLP), T cell specific-mTOR/tuberous sclerosis complex 1 (TSC1)-knockout mice, and bafilomycin A1, a specific autophagosome-lysosome (A-L) fusion inhibitor, we primarily proved that mTOR could modulate the expression and accumulation of CTLA4 by regulating the onset process of autophagy such as A-L fusion. Given such a regulatory relationship, targeting mTOR could provide new light to improve immune function in sepsis, and the prospect of using rapamycin in the clinic would be worth exploring further.

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.

Endolysosomal transient receptor potential mucolipins and two-pore channels: implications for cancer immunity

Past research has identified that cancer cells sustain several cancer hallmarks by impairing function of the endolysosomal system (ES). Thus, maintaining the functional integrity of endolysosomes is crucial, which heavily relies on two key protein families: soluble hydrolases and endolysosomal membrane proteins. Particularly members of the TPC (two-pore channel) and TRPML (transient receptor potential mucolipins) families have emerged as essential regulators of ES function as a potential target in cancer therapy. Targeting TPCs and TRPMLs has demonstrated significant impact on multiple cancer hallmarks, including proliferation, growth, migration, and angiogenesis both in vitro and in vivo. Notably, endosomes and lysosomes also actively participate in various immune regulatory mechanisms, such as phagocytosis, antigen presentation, and the release of proinflammatory mediators. Yet, knowledge about the role of TPCs and TRPMLs in immunity is scarce. This prompts a discussion regarding the potential role of endolysosomal ion channels in aiding cancers to evade immune surveillance and destruction. Specifically, understanding the interplay between endolysosomal ion channels and cancer immunity becomes crucial. Our review aims to comprehensively explore the current knowledge surrounding the roles of TPCs and TRPMLs in immunity, whilst emphasizing the critical need to elucidate their specific contributions to cancer immunity by pointing out current research gaps that should be addressed.

Immune Regulation and Immune Therapy in Melanoma: Review with Emphasis on CD155 Signalling

Melanoma is commonly diagnosed in a younger population than most other solid malignancies and, in Australia and most of the world, is the leading cause of skin-cancer-related death. Melanoma is a cancer type with high immunogenicity; thus, immunotherapies are used as first-line treatment for advanced melanoma patients. Although immunotherapies are working well, not all the patients are benefitting from them. A lack of a comprehensive understanding of immune regulation in the melanoma tumour microenvironment is a major challenge of patient stratification. Overexpression of CD155 has been reported as a key factor in melanoma immune regulation for the development of therapy resistance. A more thorough understanding of the actions of current immunotherapy strategies, their effects on immune cell subsets, and the roles that CD155 plays are essential for a rational design of novel targets of anti-cancer immunotherapies. In this review, we comprehensively discuss current anti-melanoma immunotherapy strategies and the immune response contribution of different cell lineages, including tumour endothelial cells, myeloid-derived suppressor cells, cytotoxic T cells, cancer-associated fibroblast, and nature killer cells. Finally, we explore the impact of CD155 and its receptors DNAM-1, TIGIT, and CD96 on immune cells, especially in the context of the melanoma tumour microenvironment and anti-cancer immunotherapies.

Nanoparticle-Mediated Synergistic Chemoimmunotherapy for Cancer Treatment

Until now, there has been a lack of effective strategies for cancer treatment. Immunotherapy has high potential in treating several cancers but its efficacy is limited as a monotherapy. Chemoimmunotherapy (CIT) holds promise to be widely used in cancer treatment. Therefore, identifying their involvement and potential synergy in CIT approaches is decisive. Nano-based drug delivery systems (NDDSs) are ideal delivery systems because they can simultaneously target immune cells and cancer cells, promoting drug accumulation, and reducing the toxicity of the drug. In this review, we first introduce five current immunotherapies, including immune checkpoint blocking (ICB), adoptive cell transfer therapy (ACT), cancer vaccines, oncolytic virus therapy (OVT) and cytokine therapy. Subsequently, the immunomodulatory effects of chemotherapy by inducing immunogenic cell death (ICD), promoting tumor killer cell infiltration, down-regulating immunosuppressive cells, and inhibiting immune checkpoints have been described. Finally, the NDDSs-mediated collaborative drug delivery systems have been introduced in detail, and the development of NDDSs-mediated CIT nanoparticles has been prospected.

Immunomodulatory Precision: A Narrative Review Exploring the Critical Role of Immune Checkpoint Inhibitors in Cancer Treatment

An immune checkpoint is a signaling pathway that regulates the recognition of antigens by T-cell receptors (TCRs) during an immune response. These checkpoints play a pivotal role in suppressing excessive immune responses and maintaining immune homeostasis against viral or microbial infections. There are several FDA-approved immune checkpoint inhibitors (ICIs), including ipilimumab, pembrolizumab, and avelumab. These ICIs target cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed cell death protein 1 (PD-1), and programmed death ligand 1 (PD-L1). Furthermore, ongoing efforts are focused on developing new ICIs with emerging potential. In comparison to conventional treatments, ICIs offer the advantages of reduced side effects and durable responses. There is growing interest in the potential of combining different ICIs with chemotherapy, radiation therapy, or targeted therapies. This article comprehensively reviews the classification, mechanism of action, application, and combination strategies of ICIs in various cancers and discusses their current limitations. Our objective is to contribute to the future development of more effective anticancer drugs targeting immune checkpoints.

Molecular insights into clinical trials for immune checkpoint inhibitors in colorectal cancer: Unravelling challenges and future directions

Colorectal cancer (CRC) is a complex disease with diverse etiologies and clinical outcomes. Despite considerable progress in development of CRC therapeutics, challenges remain regarding the diagnosis and management of advanced stage metastatic CRC (mCRC). In particular, the five-year survival rate is very low since mCRC is currently rarely curable. Over the past decade, cancer treatment has significantly improved with the introduction of cancer immunotherapies, specifically immune checkpoint inhibitors. Therapies aimed at blocking immune checkpoints such as PD-1, PD-L1, and CTLA-4 target inhibitory pathways of the immune system, and thereby enhance anti-tumor immunity. These therapies thus have shown promising results in many clinical trials alone or in combination. The efficacy and safety of immunotherapy, either alone or in combination with CRC, have been investigated in several clinical trials. Clinical trials, including KEYNOTE-164 and CheckMate 142, have led to Food and Drug Administration approval of the PD-1 inhibitors pembrolizumab and nivolumab, respectively, for the treatment of patients with unresectable or metastatic microsatellite instability-high or deficient mismatch repair CRC. Unfortunately, these drugs benefit only a small percentage of patients, with the benefits of immunotherapy remaining elusive for the vast majority of CRC patients. To this end, primary and secondary resistance to immunotherapy remains a significant issue, and further research is necessary to optimize the use of immunotherapy in CRC and identify biomarkers to predict the response. This review provides a comprehensive overview of the clinical trials involving immune checkpoint inhibitors in CRC. The underlying rationale, challenges faced, and potential future steps to improve the prognosis and enhance the likelihood of successful trials in this field are discussed.

Factors Governing B Cell Recognition of Autoantigen and Function in Type 1 Diabetes

Islet autoantibodies predict type 1 diabetes (T1D) but can be transient in murine and human T1D and are not thought to be directly pathogenic. Rather, these autoantibodies signal B cell activity as antigen-presenting cells (APCs) that present islet autoantigen to diabetogenic T cells to promote T1D pathogenesis. Disrupting B cell APC function prevents T1D in mouse models and has shown promise in clinical trials. Autoantigen-specific B cells thus hold potential as sophisticated T1D biomarkers and therapeutic targets. B cell receptor (BCR) somatic hypermutation is a mechanism by which B cells increase affinity for islet autoantigen. High-affinity B and T cell responses are selected in protective immune responses, but immune tolerance mechanisms are known to censor highly autoreactive clones in autoimmunity, including T1D. Thus, different selection rules often apply to autoimmune disease settings (as opposed to protective host immunity), where different autoantigen affinity ceilings are tolerated based on variations in host genetics and environment. This review will explore what is currently known regarding B cell signaling, selection, and interaction with T cells to promote T1D pathogenesis.

Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) gene polymorphisms in a cohort of Egyptian patients with immune thrombocytopenia (ITP)

BACKGROUND

Immune thrombocytopenia (ITP) is characterized by immune response dysregulations. Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) plays a central role in immune checkpoint pathways and preventing autoimmune diseases by regulating immune tolerance. We aimed to explore the potential association between CTLA-4 gene polymorphisms and ITP as well as study their impact on the response to therapy.

METHODS

We investigated two CTLA-4 single-nucleotide polymorphisms (SNPs; rs: 231775 and rs: 3087243) using real-time PCR as well as the plasma levels of CTLA-4 by ELISA in 88 patients with ITP and 44 healthy participants (HC).

RESULTS

CTLA-4 (rs: 3087243) A > G polymorphism analysis showed most HC had the homozygous AA genotype, which was statistically significant compared to patients with ITP. Plasma levels of CTLA4 were statistically lower in patients with acute ITP. There was no correlation between CTLA-4 (rs: 231775 and rs: 3087243) A/G SNPs were not correlated to the response to all lines of therapy assessed (corticosteroids, thrombopoietin receptor agonists, splenectomy, and rituximab).

CONCLUSION

CTLA-4 CT 60 A/G may affect the susceptibility of ITP, but both CTLA-4 + 49 A/G and CT60 A/G did not impact the response of patients with ITP to different lines of therapy.

Extracellular Vesicles, Circulating Tumor Cells, and Immune Checkpoint Inhibitors: Hints and Promises

Immune checkpoint inhibitor (ICI) therapy has revolutionized the treatment of cancer, in particular lung cancer, while the introduction of predictive biomarkers from liquid biopsies has emerged as a promising tool to achieve an effective and personalized therapy response. Important progress has also been made in the molecular characterization of extracellular vesicles (EVs) and circulating tumor cells (CTCs), highlighting their tremendous potential in modulating the tumor microenvironment, acting on immunomodulatory pathways, and setting up the pre-metastatic niche. Surface antigens on EVs and CTCs have proved to be particularly useful in the case of the characterization of potential immune escape mechanisms through the expression of immunosuppressive ligands or the transport of cargos that may mitigate the antitumor immune function. On the other hand, novel approaches, to increase the expression of immunostimulatory molecules or cargo contents that can enhance the immune response, offer premium options in combinatorial clinical strategies for precision immunotherapy. In this review, we discuss recent advances in the identification of immune checkpoints using EVs and CTCs, their potential applications as predictive biomarkers for ICI therapy, and their prospective use as innovative clinical tools, considering that CTCs have already been approved by the Food and Drug Administration (FDA) for clinical use, but providing good reasons to intensify the research on both.

Modern cancer therapy: cryoablation meets immune checkpoint blockade

Cryoablation, as a minimally invasive technology for the treatment of tumors, destroys target tumors with lethal low temperatures. It simultaneously releases a large number of tumor-specific antigens, pro-inflammatory cytokines, and nucleoproteins, known as "danger signals", activating the body's innate and adaptive immune responses. However, tumor cells can promote the inactivation of immune effector cells by reprogramming immune checkpoints, leading to the insufficiency of these antigens to induce an immune response capable of eradicating the tumor. Immune checkpoint blockers rejuvenate exhausted T cells by blocking immune checkpoints that induce programmed death of T cells, and are therefore considered a promising therapeutic strategy to enhance the immune effects of cryoablation. In this review, we provide a detailed explanation of the immunological mechanisms of cryoablation and articulate the theoretical basis and research progress of the treatment of cancer with cryoablation combined with immune checkpoint blockers. Preliminary data indicates that this combined treatment strategy exhibits good synergy and has been proven to be safe and effective.

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.

A comprehensive review of dermatomyositis treatments - from rediscovered classics to promising horizons

INTRODUCTION

Dermatomyositis (DM) is a rare inflammatory disease with diverse cutaneous and systemic manifestations, often associated with myositis-specific antibodies. Managing patients with refractory DM, or individuals presenting pecific complications, like calcinosis or rapidly progressive interstitial lung disease, presents unique challenges.

AREAS COVERED

This review explores current and promising treatment options for DM, drawing from clinical studies, case series, and case reports that consider the underlying disease pathophysiology.

EXPERT OPINION

Recent advancements have improved our understanding and management of DM. The discovery of distinct DM autoantibodies and their correlation with specific clinical phenotypes has transformed patient categorization and enhanced our knowledge of the pathogenesis of the disease. Intravenous immunoglobulin, a well-established treatment in dermatomyositis, has regained prominence and a large randomized clinical trial has reaffirmed its efficacy, confirming it as an effective therapeutic option in this group of patients. Identification of the type I interferon pathway as a key pathogenic mechanism in DM has opened up new avenues for more effective treatment strategies. Blocking the JAK/STAT pathway offers potential for improved management of refractory patients and prevention of highly morbid complications. These recent advancements have significantly impacted the management and care of dermatomyositis patients, enabling tailored approaches, targeted interventions, and improved outcomes for individuals affected by this complex condition.

The JAK-STAT Pathway as a Therapeutic Strategy in Cancer Patients with Immune Checkpoint Inhibitor-Induced Colitis: A Narrative Review

Immunotherapy has emerged as a pivotal component in the treatment of various malignancies, encompassing lung, skin, gastrointestinal, and head and neck cancers. The foundation of this therapeutic approach lies in immune checkpoint inhibitors (ICI). While ICIs have demonstrated remarkable efficacy in impeding the neoplastic progression of these tumours, their use may give rise to substantial toxicity, notably in the gastrointestinal domain, where ICI colitis constitutes a significant aspect. The optimal positioning of Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway inhibitors in the therapeutic management of ICI colitis remains unclear. Numerous reports have highlighted notable improvements in ICI colitis through the application of pan-JAK-STAT inhibitors, with tofacitinib, in particular, reporting evident clinical remission of colitis. The precise mechanism by which JAK-STAT inhibitors may impact the pathogenetic process of ICI colitis remains inadequately understood. However, there is speculation regarding their potential role in modulating memory resident CD8+ T lymphocytes. The elucidation of this mechanism requires further extensive and robust evidence, and ongoing JAK-STAT-based trials are anticipated to contribute valuable insights.

Immune checkpoint blockade in hematological malignancies: current state and future potential

Malignant cells are known to evade immune surveillance by engaging immune checkpoints which are negative regulators of the immune system. By restoring the T-lymphocyte mediated anti-tumor effect, immune checkpoint inhibitors (ICI) have revolutionized the treatment of solid tumors but have met rather modest success in hematological malignancies. Currently, the only FDA approved indications for ICI therapy are in classic hodgkin lymphoma and primary mediastinal B cell lymphoma. Multiple clinical trials have assessed ICI therapy alone and in combination with standard of care treatments in other lymphomas, plasma cell neoplasms and myeloid neoplasms but were noted to have limited efficacy. These trials mostly focused on PD-1/PDL-1 and CTLA-4 inhibitors. Recently, there has been an effort to target other T-lymphocyte checkpoints like LAG-3, TIM-3, TIGIT along with improving strategies of PD-1/PDL-1 and CTLA-4 inhibition. Drugs targeting the macrophage checkpoint, CD47, are also being tested. Long term safety and efficacy data from these ongoing studies are eagerly awaited. In this comprehensive review, we discuss the mechanism of immune checkpoint inhibitors, the key takeaways from the reported results of completed and ongoing studies of these therapies in the context of hematological malignancies.

Anti-CTLA-4 nanobody as a promising approach in cancer immunotherapy

Cancer is one of the most common diseases and causes of death worldwide. Since common treatment approaches do not yield acceptable results in many patients, developing innovative strategies for effective treatment is necessary. Immunotherapy is one of the promising approaches that has been highly regarded for preventing tumor recurrence and new metastases. Meanwhile, inhibiting immune checkpoints is one of the most attractive methods of cancer immunotherapy. Cytotoxic T lymphocyte-associated protein-4 (CTLA-4) is an essential immune molecule that plays a vital role in cell cycle modulation, regulation of T cell proliferation, and cytokine production. This molecule is classically expressed by stimulated T cells. Inhibition of overexpression of immune checkpoints such as CTLA-4 receptors has been confirmed as an effective strategy. In cancer immunotherapy, immune checkpoint-blocking drugs can be enhanced with nanobodies that target immune checkpoint molecules. Nanobodies are derived from the variable domain of heavy antibody chains. These small protein fragments have evolved entirely without a light chain and can be used as a powerful tool in imaging and treating diseases with their unique structure. They have a low molecular weight, which makes them smaller than conventional antibodies while still being able to bind to specific antigens. In addition to low molecular weight, specific binding to targets, resistance to temperature, pH, and enzymes, high ability to penetrate tumor tissues, and low toxicity make nanobodies an ideal approach to overcome the disadvantages of monoclonal antibody-based immunotherapy. In this article, while reviewing the cellular and molecular functions of CTLA-4, the structure and mechanisms of nanobodies' activity, and their delivery methods, we will explain the advantages and challenges of using nanobodies, emphasizing immunotherapy treatments based on anti-CTLA-4 nanobodies.

High CTLA-4 transcriptomic expression correlates with high expression of other checkpoints and with immunotherapy outcome

Background

CTLA-4 impedes the immune system's antitumor response. There are two Food and Drug Administration-approved anti-CTLA-4 agents - ipilimumab and tremelimumab - both used together with anti-PD-1/PD-L1 agents.

Objective

To assess the prognostic implications and immunologic correlates of high CTLA-4 in tumors of patients on immunotherapy and those on non-immunotherapy treatments.

Design/methods

We evaluated RNA expression levels in a clinical-grade laboratory and clinical correlates of CTLA-4 and other immune checkpoints in 514 tumors, including 489 patients with advanced/metastatic cancers and full outcome annotation. A reference population (735 tumors; 35 histologies) was used to normalize and rank transcript abundance (0-100 percentile) to internal housekeeping gene profiles.

Results

The most common tumor types were colorectal (140/514, 27%), pancreatic (55/514, 11%), breast (49/514, 10%), and ovarian cancers (43/514, 8%). Overall, 87 of 514 tumors (16.9%) had high CTLA-4 transcript expression (⩾75th percentile rank). Cancers with the largest proportion of high CTLA-4 transcripts were cervical cancer (80% of patients), small intestine cancer (33.3%), and melanoma (33.3%). High CTLA-4 RNA independently/significantly correlated with high PD-1, PD- L2, and LAG3 RNA levels (and with high PD-L1 in univariate analysis). High CTLA-4 RNA expression was not correlated with survival from the time of metastatic disease [N = 272 patients who never received immune checkpoint inhibitors (ICIs)]. However, in 217 patients treated with ICIs (mostly anti-PD-1/anti-PD- L1), progression-free survival (PFS) and overall survival (OS) were significantly longer among patients with high versus non-high CTLA-4 expression [hazard ratio, 95% confidence interval: 0.6 (0.4-0.9) p = 0.008; and 0.5 (0.3-0.8) p = 0.002, respectively]; results were unchanged when 18 patients who received anti-CTLA-4 were omitted. Patients whose tumors had high CTLA-4 and high PD-L1 did best; those with high PD-L1 but non-high CTLA-4 and/or other expression patterns had poorer outcomes for PFS (p = 0.004) and OS (p = 0.009) after immunotherapy.

Conclusion

High CTLA-4, especially when combined with high PD-L1 transcript expression, was a significant positive predictive biomarker for better outcomes (PFS and OS) in patients on immunotherapy.

CD80-Fc fusion protein as a potential cancer immunotherapy strategy

The activation of T lymphocytes is a crucial component of the immune response, and the presence of CD80, a membrane antigen, is necessary for T-cell activation. CD80 is usually expressed on antigen-presenting cells (APCs), which can interact with cluster of differentiation 28 (CD28) or programmed cell death ligand 1 (PD-L1) to promote T-cell proliferation, differentiation and function by activating costimulatory signal or blocking inhibitory signal. Simultaneously, CD80 on the APCs also interacts with cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) on the surface of T cells to suppress the response of specific effector T cells, particularly in the context of persistent antigenic stimulation. Due to the pivotal role of CD80 in the immune response, the CD80-Fc fusion protein has emerged as a promising approach for cancer immunotherapy. This review primarily focused on the crucial role of CD80 in the cancer immunotherapy. We also reviewed the current advancements in the research of CD80-Fc fusion proteins. Finally, we deliberated on the challenges encountered by CD80-Fc fusion proteins and proposed the potential strategies that could yield the benefits for patients.

A Peripheral Blood Signature of Increased Th1 and Myeloid Cells Combined with Serum Inflammatory Mediators Is Associated with Response to Abatacept in Rheumatoid Arthritis Patients

Abatacept (CTLA4-Ig)-a monoclonal antibody which restricts T cell activation-is an effective treatment for rheumatoid arthritis (RA). Nevertheless, only 50% of RA patients attain clinical responses, while predictors of response are rather limited. Herein, we aimed to investigate for early biomarkers of response to abatacept, based on a detailed immunological profiling of peripheral blood (PB) cells and serum proteins. We applied flow cytometry and proteomics analysis on PB immune cells and serum respectively, of RA patients starting abatacept as the first biologic agent. After 6 months of treatment, 34.5% of patients attained response. At baseline, Th1 and FoxP3+ T cell populations were positively correlated with tender joint counts (p-value = 0.047 and p-value = 0.022, respectively). Upon treatment, CTLA4-Ig effectively reduced the percentages of Th1 and Th17 only in responders (p-value = 0.0277 and p-value = 0.0042, respectively). Notably, baseline levels of Th1 and myeloid cell populations were significantly increased in PB of responders compared to non-responders (p-value = 0.009 and p-value = 0.03, respectively). Proteomics analysis revealed that several inflammatory mediators were present in serum of responders before therapy initiation and strikingly 10 amongst 303 serum proteins were associated with clinical responses. Finally, a composite index based on selected baseline cellular and proteomics' analysis could predict response to abatacept with a high sensitivity (90%) and specificity (88.24%).

Immune checkpoints in rheumatoid arthritis: progress and promise

Rheumatoid arthritis (RA) is one of the most prevalent autoimmune inflammatory conditions, and while the mechanisms driving pathogenesis are yet to be completely elucidated, self-reactive T cells and immune checkpoint pathways have a clear role. In this review, we provide an overview of the importance of checkpoint pathways in the T cell response and describe the involvement of these in RA development and progression. We discuss the relationship between immune checkpoint therapy in cancer and autoimmune adverse events, draw parallels with the involvement of immune checkpoints in RA pathobiology, summarise emerging research into some of the lesser-known pathways, and the potential of targeting checkpoint-related pathways in future treatment approaches to RA management.

Immunotherapy and biomarkers in patients with lung cancer with tuberculosis: Recent advances and future Directions

Lung cancer (LC) and tuberculosis (TB) are two major global public health problems, and the incidence of LC-TB is currently on the rise. Therefore effective clinical interventions are crucial for LC-TB. The aim of this review is to provide up-to-date information on the immunological profile and therapeutic biomarkers in patients with LC-TB. We discuss the immune mechanisms involved, including the immune checkpoints that play an important role in the treatment of patients with LC-TB. In addition, we explore the susceptibility of patients with LC to TB and summarise the latest research on LC-TB. Finally, we discuss future prospects in this field, including the identification of potential targets for immune intervention. In conclusion, this review provides important insights into the complex relationship between LC and TB and highlights new advances in the detection and treatment of both diseases.

Combinatorial blockade for cancer immunotherapy: targeting emerging immune checkpoint receptors

The differentiation, survival, and effector function of tumor-specific CD8+ cytotoxic T cells lie at the center of antitumor immunity. Due to the lack of proper costimulation and the abundant immunosuppressive mechanisms, tumor-specific T cells show a lack of persistence and exhausted and dysfunctional phenotypes. Multiple coinhibitory receptors, such as PD-1, CTLA-4, VISTA, TIGIT, TIM-3, and LAG-3, contribute to dysfunctional CTLs and failed antitumor immunity. These coinhibitory receptors are collectively called immune checkpoint receptors (ICRs). Immune checkpoint inhibitors (ICIs) targeting these ICRs have become the cornerstone for cancer immunotherapy as they have established new clinical paradigms for an expanding range of previously untreatable cancers. Given the nonredundant yet convergent molecular pathways mediated by various ICRs, combinatorial immunotherapies are being tested to bring synergistic benefits to patients. In this review, we summarize the mechanisms of several emerging ICRs, including VISTA, TIGIT, TIM-3, and LAG-3, and the preclinical and clinical data supporting combinatorial strategies to improve existing ICI therapies.

Expression of PD-1 and PD-L1 in Endometrial Cancer: Molecular and Clinical Significance

The landscape of diagnosing and treating endometrial cancer is undergoing a profound transformation due to the integration of molecular analysis and innovative therapeutic approaches. For several decades, the cornerstone treatments for endometrial cancer have included surgical resection, cytotoxic chemotherapy, hormonal therapy, and radiation therapy. However, in recent years, the concept of personalised medicine has gained momentum, reshaping the way clinicians approach cancer treatment. Tailoring treatments based on specific biomarkers has evolved into a standard practice in both initial and recurrent therapy protocols. This review aims to provide an in-depth exploration of the current state of molecular analysis and treatment strategies in the context of endometrial cancer, focusing on the immunological aspect of the PD-1/PD-L1 axis. Furthermore, it seeks to shed light on emerging and innovative approaches that hold promise for the future modulation of endometrial cancer treatments. In essence, as researchers delve into the complex molecular landscape of endometrial cancer and harness the understanding of the PD-1/PD-L1 axis, we are paving the way for more targeted, effective, and personalised therapies that have the potential to significantly improve the outcomes and quality of life for patients with this challenging disease.

The Microbiome in Advanced Melanoma: Where Are We Now?

PURPOSE OF REVIEW

This review summarizes recent data linking gut microbiota composition to ICI outcomes and gut microbiota-specific interventional clinical trials in melanoma.

RECENT FINDINGS

Preclinical and clinical studies have demonstrated the effects of the gut microbiome modulation upon ICI response in advanced melanoma, with growing evidence supporting the ability of the gut microbiome to restore or improve ICI response in advanced melanoma through dietary fiber, probiotics, and FMT. Immune checkpoint inhibitors (ICI) targeting the PD-1, CTLA-4, and LAG-3 negative regulatory checkpoints have transformed the management of melanoma. ICIs are FDA-approved in advanced metastatic disease, stage III resected melanoma, and high-risk stage II melanoma and are being investigated more recently in the management of high-risk resectable melanoma in the peri-operative setting. The gut microbiome has emerged as an important tumor-extrinsic modulator of both response and immune-related adverse event (irAE) development in ICI-treated cancer in general, and melanoma in particular.

The bladder cancer immune micro-environment in the context of response to immune checkpoint inhibition

Treatment with neoadjuvant cisplatin-based chemotherapy followed by radical cystectomy is the default treatment for muscle-invasive bladder cancer (BC). However, with the encouraging results of immune checkpoint inhibitiors (ICI) directed against PD-1/PD-L1 and CTLA-4 in recent years, the treatment landscape of BC is rapidly changing. In addition, it is becoming clear that the effect of ICI is highly dependent on the interaction between tumor cells and the tumor immune micro-environment (TIME). Different immune cells are involved in an anti-tumor response in BC. Cytotoxic CD8+ T-cells are the main effector cells, aided by other immune cells including other T-cells, B-cells and pro-inflammatory macrophages. As part of the ongoing anti-tumor immune response, lymphocytes aggregate in clusters called tertiary lymphoid structures (TLS). Tumor mutational burden (TMB) and infiltration of immune cells into the tumor are both important factors for establishing an anti-tumor immune response. In contrast, transforming growth factor beta (TGF-β) signaling in cancer-associated fibroblasts (CAFs) prevents infiltration of lymphocytes and potentially has an immunosuppressive effect. In conclusion, the effect of ICI seems to be reliant on a combination of tumor-intrinsic and TIME-related parameters. More research is needed to fully understand the underlying biological mechanisms to further improve patient care.

Both intratumoral regulatory T cell depletion and CTLA-4 antagonism are required for maximum efficacy of anti-CTLA-4 antibodies

Anti-CTLA-4 antibodies have successfully elicited durable tumor regression in the clinic; however, long-term benefit is limited to a subset of patients for select cancer indications. The incomplete understanding of their mechanism of action has hindered efforts at improvement, with conflicting hypotheses proposing either antagonism of the CTLA-4:B7 axis or Fc effector-mediated regulatory T cell (Treg) depletion governing efficacy. Here, we report the engineering of a nonantagonistic CTLA-4 binding domain (b1s1e2) that depletes intratumoral Tregs as an Fc fusion. Comparison of b1s1e2-Fc to 9d9, an antagonistic anti-CTLA-4 antibody, allowed for interrogation of the separate contributions of CTLA-4 antagonism and Treg depletion to efficacy. Despite equivalent levels of intratumoral Treg depletion, 9d9 achieved more long-term cures than b1s1e2-Fc in MC38 tumors, demonstrating that CTLA-4 antagonism provided additional survival benefit. Consistent with prior reports that CTLA-4 antagonism enhances priming, treatment with 9d9, but not b1s1e2-Fc, increased the percentage of activated T cells in the tumor-draining lymph node (tdLN). Treg depletion with either construct was restricted to the tumor due to insufficient surface CTLA-4 expression on Tregs in other compartments. Through intratumoral administration of diphtheria toxin in Foxp3-DTR mice, we show that depletion of both intratumoral and nodal Tregs provided even greater survival benefit than 9d9, consistent with Treg-driven restraint of priming in the tdLN. Our data demonstrate that anti-CTLA-4 therapies require both CTLA-4 antagonism and intratumoral Treg depletion for maximum efficacy-but that potential future therapies also capable of depleting nodal Tregs could show efficacy in the absence of CTLA-4 antagonism.

Mechanisms underlying response and resistance to immune checkpoint blockade in cancer immunotherapy

Cancer immunotherapies targeting immune checkpoint pathways, such as programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), have achieved unprecedented therapeutic success in treating various types of cancer. The prominent and persistent clinical responses to immune checkpoint blockade (ICB) therapy are currently constrained to a subset of patients. Owing to discrete individual tumor and immune heterogeneity, most patients fail to benefit from ICB treatment, demonstrating either primary or acquired resistance. A thorough comprehension of the mechanisms restricting the efficacy of immune checkpoint inhibitors (ICIs) is required to extend their clinical applicability to a broader spectrum of patients and cancer types. Numerous studies are presently investigating potential prognostic markers of responsiveness, the complex dynamics underlying the therapeutic and adverse effects of ICB, and tumor immune evasion throughout the course of immunotherapy. In this article, we have reviewed the extant literature elucidating the mechanisms underlying the response and resistance to ICB, with a particular emphasis on PD-1 and CTLA-4 pathway blockade in the context of anti-tumor immunity. Furthermore, we aimed to explore potential approaches to overcome cancer therapeutic resistance and develop a rational design for more personalized ICB-based combinational regimens.

Mechanisms of Altered Immune Response in Skin Melanoma

Melanoma, a deadly form of skin cancer, poses significant challenges to the host immune system, allowing tumor cells to evade immune surveillance and persist. This complex interplay between melanoma and the immune system involves a multitude of mechanisms that impair immune recognition and promote tumor progression. This review summarizes the intricate strategies employed by melanoma cells to evade the immune response, including defective immune recognition, immune checkpoint activation, and the role of regulatory T-cells, myeloid-derived suppressor cells, and exosomes in suppressing anti-tumor immunity. Additionally, we discuss potential therapeutic targets aimed at reversing immune evasion in melanoma, highlighting the importance of understanding these mechanisms for developing more effective immunotherapies. Improved insights into the interactions between melanoma and the immune system will aid in the development of novel treatment strategies to enhance anti-tumor immune responses and improve patient outcomes.

New developments in the mechanism and application of immune checkpoint inhibitors in cancer therapy (Review)

The use of immune checkpoint inhibitors (ICIs) has been demonstrated in the treatment of numerous types of cancer and ICIs have remained a key focus of cancer research. However, improvements in survival rates only occur in a subset of patients, due to the complexity of drug resistance. Therefore, further investigations are required to identify predictive biomarkers that distinguish responders and non‑responders. Combined therapeutics involving ICIs and other modalities demonstrate potential in overcoming resistance to ICIs; however, further preclinical and clinical trials are required. Concurrently, prompt recognition and intervention of immune‑related adverse events are crucial to optimize the use of ICIs in clinical treatment. The present study aimed to review the current literature surrounding the mechanisms and application of ICIs, with the aim of providing a theoretical basis for clinicians.

Efficacy of COVID-19 mRNA vaccination in patients with autoimmune disorders: humoral and cellular immune response

BACKGROUND

The impact of immunosuppressive therapies on the efficacy of vaccines to SARS-CoV-2 is not completely clarified. We analyzed humoral and T cell-mediated response after COVID-19 mRNA vaccine in immunosuppressed patients and patients with common variable immunodeficiency disease (CVID).

PATIENTS

We enrolled 38 patients and 11 healthy sex- and age-matched controls (HC). Four patients were affected by CVID and 34 by chronic rheumatic diseases (RDs). All patients with RDs were treated by corticosteroid therapy and/or immunosuppressive treatment and/or biological drugs: 14 patients were treated with abatacept, 10 with rituximab, and 10 with tocilizumab.

METHODS

Total antibody titer to SARS-CoV-2 spike protein was assessed by electrochemiluminescence immunoassay, CD4 and CD4-CD8 T cell-mediated immune response was analyzed by interferon-γ (IFN-γ) release assay, the production of IFN-γ-inducible (CXCL9 and CXCL10) and innate-immunity chemokines (MCP-1, CXCL8, and CCL5) by cytometric bead array after stimulation with different spike peptides. The expression of CD40L, CD137, IL-2, IFN-γ, and IL-17 on CD4 and CD8 T cells, evaluating their activation status, after SARS-CoV-2 spike peptides stimulation, was analyzed by intracellular flow cytometry staining. Cluster analysis identified cluster 1, namely the "high immunosuppression" cluster, and cluster 2, namely the "low immunosuppression" cluster.

RESULTS

After the second dose of vaccine, only abatacept-treated patients, compared to HC, showed a reduced anti-spike antibody response (mean: 432 IU/ml ± 562 vs mean: 1479 IU/ml ± 1051: p = 0.0034), and an impaired T cell response, compared with HC. In particular, we found a significantly reduced release of IFN-γ from CD4 and CD4-CD8 stimulated T cells, compared with HC (p = 0.0016 and p = 0.0078, respectively), reduced production of CXCL10 and CXCL9 from stimulated CD4 (p = 0.0048 and p = 0.001) and CD4-CD8 T cells (p = 0.0079 and p = 0.0006). Multivariable General Linear Model analysis confirmed a relationship between abatacept exposure and impaired production of CXCL9, CXCL10, and IFN-γ from stimulated T cells. Cluster analysis confirms that cluster 1 (including abatacept and half of rituximab treated cases) showed a reduced IFN-γ response, as well as reduced monocyte-derived chemokines All groups of patients demonstrated the ability to generate specific CD4 T activated cells after spike proteins stimulation. After the third dose of vaccine, abatacept-treated patients acquired the ability to produce a strong antibody response, showing an anti-S titer significantly higher compared to that obtained after the second dose (p = 0.0047), and comparable with the anti-S titer of the other groups.

CONCLUSIONS

Patients treated with abatacept showed an impaired humoral immune response to two doses of COVID-19 vaccine. The third vaccine dose has been demonstrated to be useful to induce a more robust antibody response to balance an impaired T cell-mediated one. All patients, exposed to different immunosuppressive drugs, were able to produce specific CD4-activated T cells, after spike proteins stimulation.

TRIAL REGISTRATION

Local Ethical Committee NP4187.

CD44 is a potential immunotherapeutic target and affects macrophage infiltration leading to poor prognosis

CD44 plays a key role in the communication of CSCs with the microenvironment and the regulation of stem cell properties. UALCAN was used to analyze the expression of CD44 in bladder cancer (BLCA) and normal tissue. The UALCAN was utilized to analyze the prognostic value of CD44 in BLCA. The TIMER database was used to explore the relationship between CD44 and PD-L1; CD44 and tumor-infiltrating immune cells. The regulatory effect of CD44 on PD-L1 was verified by cell experiments in vitro. IHC confirmed the results of the bioinformatics analysis. GeneMania and Metascape were used to analyze protein-protein interaction (PPI) investigations and functional enrichment analysis. We found that BLCA patients with high CD44 expression had worse survival than those with low CD44 expression (P < 0.05). IHC and the TIMER database results showed that CD44 expression was positively correlated with PD-L1 expression (P < 0.05). At the cellular level, the expression of PD-L1 was significantly inhibited after CD44 expression was inhibited by siRNA. Immune infiltration analysis showed that CD44 expression levels in BLCA were significantly correlated with immune infiltration levels of different immune cells. IHC staining results further confirmed that the expression of CD44 in tumor cells was positively associated with the number of CD68⁺ macrophages and CD163⁺ macrophages (P < 0.05). Our results suggest that CD44 is a positive regulator of PD-L1 in BLCA and may be a key regulator of tumor macrophages infiltration and may be involved in M2 macrophage polarization. Our study provided new insights into the prognosis and immunotherapy of BLCA patients through macrophage infiltration and immune checkpoints.

Modulation of T cell function and survival by the tumor microenvironment

Cancer immunotherapy is shifting paradigms in cancer care. T cells are an indispensable component of an effective antitumor immunity and durable clinical responses. However, the complexity of the tumor microenvironment (TME), which consists of a wide range of cells that exert positive and negative effects on T cell function and survival, makes achieving robust and durable T cell responses difficult. Additionally, tumor biology, structural and architectural features, intratumoral nutrients and soluble factors, and metabolism impact the quality of the T cell response. We discuss the factors and interactions that modulate T cell function and survive in the TME that affect the overall quality of the antitumor immune response.

Relationship between the tumor microenvironment and the efficacy of the combination of radiotherapy and immunotherapy

Activating and recruiting the immune system is critical for successful cancer treatment. Since the discovery of immune checkpoint inhibitors, immunotherapy has become the standard of care for many types of cancers. However, many patients fail to respond to immunotherapy. Further research is needed to understand the mechanisms of resistance and adjuvant therapies that can help sensitize patients to immunotherapies. Here, we will discuss how radiotherapy can change the tumor microenvironment and work synergistically with immunotherapy. We will examine different pre-clinical models focusing on their limitations and their unique advantages in studying the efficacy of treatments and the tumor microenvironment. We will also describe emerging findings from clinical trials testing the combination of immunotherapy and radiotherapy.

Immunotherapy or targeted therapy: What will be the future treatment for anaplastic thyroid carcinoma?

Anaplastic thyroid carcinoma (ATC) is a rare and aggressive form of thyroid carcinoma (TC). Currently, there are no effective treatments for this condition. In the past few years, targeted therapy and immunotherapy have made significant progress in ATC treatment. Several common genetic mutations have been found in ATC cells, involving different molecular pathways related to tumor progression, and new therapies that act on these molecular pathways have been studied to improve the quality of life of these patients. In 2018, the FDA approved dabrafenib combined with trametinib to treat BRAF-positive ATC, confirming its therapeutic potential. At the same time, the recent emergence of immunotherapy has also attracted wide attention from researchers. While immunotherapy for ATC is still in the experimental stage, numerous studies have shown that immunotherapy is a potential therapy for ATC. In addition, it has also been found that the combination of immunotherapy and targeted therapy may enhance the anti-tumor effect of targeted therapy. In recent years, there has been some progress in the study of targeted therapy or immunotherapy combined with radiotherapy or chemotherapy, showing the prospect of combined therapy in ATC. In this review, we analyze the response mechanism and potential effects of targeted therapy, immunotherapy, and combination therapy in ATC treatment and explore the future of treatment for ATC.

A lesion-selective albumin-CTLA4Ig as a safe and effective treatment for collagen-induced arthritis

BACKGROUND

CTLA4Ig is a dimeric fusion protein of the extracellular domain of cytotoxic T-lymphocyte protein 4 (CTLA4) and an Fc (Ig) fragment of human IgG₁ that is approved for treating rheumatoid arthritis. However, CTLA4Ig may induce adverse effects. Developing a lesion-selective variant of CTLA4Ig may improve safety while maintaining the efficacy of the treatment.

METHODS

We linked albumin to the N-terminus of CTLA4Ig (termed Alb-CTLA4Ig) via a substrate sequence of matrix metalloproteinase (MMP). The binding activities and the biological activities of Alb-CTLA4Ig before and after MMP digestion were analyzed by a cell-based ELISA and an in vitro Jurkat T cell activation assay. The efficacy and safety of Alb-CTLA4Ig in treating joint inflammation were tested in mouse collagen-induced arthritis.

RESULTS

Alb-CTLA4Ig is stable and inactive under physiological conditions but can be fully activated by MMPs. The binding activity of nondigested Alb-CTLA4Ig was at least 10,000-fold weaker than that of MMP-digested Alb-CTLA4Ig. Nondigested Alb-CTLA4Ig was unable to inhibit Jurkat T cell activation, whereas MMP-digested Alb-CTLA4Ig was as potent as conventional CTLA4Ig in inhibiting the T cells. Alb-CTLA4Ig was converted to CTLA4Ig in the inflamed joints to treat mouse collagen-induced arthritis, showing similar efficacy to that of conventional CTLA4Ig. In contrast to conventional CTLA4Ig, Alb-CTLA4Ig did not inhibit the antimicrobial responses in the spleens of the treated mice.

CONCLUSIONS

Our study indicates that Alb-CTLA4Ig can be activated by MMPs to suppress tissue inflammation in situ. Thus, Alb-CTLA4Ig is a safe and effective treatment for collagen-induced arthritis in mice.

A systematic review and meta-analysis of immune checkpoint therapy in relapsed or refractory non-Hodgkin lymphoma; a friend or foe?

Over the last decades, a revolution has occurred in oncology with the development of immune checkpoint inhibitors (ICIs). Following tremendous successes in solid tumors, interest has risen to explore these inhibitors in hematologic malignancies; while Hodgkin's lymphoma (HL) has shown overwhelming achievements, available data on different types of non-Hodgkin's lymphoma (NHL) vary considerably. To the best of our knowledge, no meta-analysis has assessed the efficacy and safety of ICI therapy in relapsed or refractory NHL patients. Meta-analysis of the included studies (n = 29) indicated PD-1 may probably be the more attractive ICI target rather than PD-L1 and CTLA-4 in NHL patients. Also, there is a plausible correlation between NHL subtypes and response to ICI therapy. While MF, ENKTL, RT, and PMBCL showed promising responses to ICI monotherapy, neither FL nor DLBCL had satisfactory responses; further necessitating novel strategies such as the application of ICIs in combination with other treatment strategies. Notably, among different combinations, BTK inhibitors showed an obvious improvement as compared to ICI monotherapy in both FL and DLBCL, however, the best results were obtained when ICI was combined with anti-CD20 monoclonal antibodies. Finally, while most NHL patients who received ICI treatment have experienced mild AEs, larger trials with long-term follow-up are required to confirm the safety, as well as the efficacy, of ICI therapy in NHL patients.

Immunotherapies in rare cancers

Cancer remains a leading cause of death worldwide, placing a significant burden on healthcare systems as well as the global economy. Rare cancers comprise a group of about 200 cancers that individually occur at extremely low frequencies. In the United States (US), their frequency is approximately 15 cases per 100,000 people, and it is even lower in Europe with approximately 6 cases per 100,000 people. However, combined their frequency of occurrence is much higher than any singular cancer. Cancer treatment and management has tremendously improved in the last decade, particularly with the administration of immune-based therapies. The four most prevalent immune-based therapies are (1) the use of immune-checkpoint inhibitors, (2) macrophage therapy, (3) Chimeric Antigen Receptor (CAR) T cell therapy, and (4) neoantigen-based therapies. In our review, we discuss these various aproaches and their implementation in the treatment of a variety of rare cancers. Furthermore, we discuss their limitations and potential strategies to overcome them to enhance the therapeutic efficacy of these approaches. Finally, our article presents the future directions and other additional immune therapies that may be incorporated into the treatment of rare cancers.

Advances in antibody-based therapy in oncology

Monoclonal antibodies are a growing class of targeted cancer therapeutics, characterized by exquisite specificity, long serum half-life, high affinity and immune effector functions. In this review, we outline key advances in the field with a particular focus on recent and emerging classes of engineered antibody therapeutic candidates, discuss molecular structure and mechanisms of action and provide updates on clinical development and practice.

Efficacy of immune checkpoint inhibitor monotherapy or combined with other small molecule-targeted agents in ovarian cancer

Ovarian cancer is the most lethal female reproductive system tumour. Despite the great advances in surgery and systemic chemotherapy over the past two decades, almost all patients in stages III and IV relapse and develop resistance to chemotherapy after first-line treatment. Ovarian cancer has an extraordinarily complex immunosuppressive tumour microenvironment in which immune checkpoints negatively regulate T cells activation and weaken antitumour immune responses by delivering immunosuppressive signals. Therefore, inhibition of immune checkpoints can break down the state of immunosuppression. Indeed, Immune checkpoint inhibitors (ICIs) have revolutionised the therapeutic landscape of many solid tumours. However, ICIs have yielded modest benefits in ovarian cancer. Therefore, a more comprehensive understanding of the mechanistic basis of the immune checkpoints is needed to improve the efficacy of ICIs in ovarian cancer. In this review, we systematically introduce the mechanisms and expression of immune checkpoints in ovarian cancer. Moreover, this review summarises recent updates regarding ICI monotherapy or combined with other small-molecule-targeted agents in ovarian cancer.

Targeting immune checkpoints in anti-neutrophil cytoplasmic antibodies associated vasculitis: the potential therapeutic targets in the future

Anti-neutrophil cytoplasmic autoantibodies (ANCA) associated vasculitis (AAV) is a necrotizing vasculitis mainly involving small blood vessels. It is demonstrated that T cells are important in the pathogenesis of AAV, including regulatory T cells (Treg) and helper T cells (Th), especially Th2, Th17, and follicular Th cells (Tfh). In addition, the exhaustion of T cells predicted the favorable prognosis of AAV. The immune checkpoints (ICs) consist of a group of co-stimulatory and co-inhibitory molecules expressed on the surface of T cells, which maintains a balance between the activation and exhaustion of T cells. CD28, inducible T-cell co-stimulator (ICOS), OX40, CD40L, glucocorticoid induced tumor necrosis factor receptor (GITR), and CD137 are the common co-stimulatory molecules, while the programmed cell death 1 (PD-1), cytotoxic T lymphocyte-associated molecule 4 (CTLA-4), T cell immunoglobulin (Ig) and mucin domain-containing protein 3 (TIM-3), B and T lymphocyte attenuator (BTLA), V-domain Ig suppressor of T cell activation (VISTA), T-cell Ig and ITIM domain (TIGIT), CD200, and lymphocyte activation gene 3 (LAG-3) belong to co-inhibitory molecules. If this balance was disrupted and the activation of T cells was increased, autoimmune diseases (AIDs) might be induced. Even in the treatment of malignant tumors, activation of T cells by immune checkpoint inhibitors (ICIs) may result in AIDs known as rheumatic immune-related adverse events (Rh-irAEs), suggesting the importance of ICs in AIDs. In this review, we summarized the features of AAV induced by immunotherapy using ICIs in patients with malignant tumors, and then reviewed the biological characteristics of different ICs. Our aim was to explore potential targets in ICs for future treatment of AAV.

The effect of combining PD-1 agonist and low-dose Interleukin-2 on treating systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease involving multiple organs. It is often called "immortal cancer" due to the difficulties in disease treatment. As the cornerstone of immune regulation, the programmed cell death protein 1 (PD-1) has been extensively studied in the context of chronic inflammation due to its ability of regulating immune response and immunosuppression. Recently, more and more studies on rheumatic immune related complications have also focused on PD-1 and proposed that the use of PD-1 agonist could inhibit the activation of lymphocytes and alleviate SLE disease activity. In this review, we summarized the role of PD-1 in SLE, implicating its potential application as a biomarker to predict SLE disease activity; we also proposed that the combination of PD-1 agonist and low-dose IL-2 may have better therapeutic efficacy, shining light on a new direction for developing specific treatment approaches.