Checkpoint inhibitors (CPI) and autoimmune chronic inflammatory diseases (ACIDs): tolerance and loss of tolerance in the occurrence of immuno-rheumatologic manifestations

What do we know about co-stimulatory and co-inhibitory immune checkpoint signals in ankylosing spondylitis?

Ankylosing spondylitis is the main entity of a family of inflammatory diseases affecting many musculoskeletal (sacroiliac joints, spine, and peripheral joints) and extra-musculoskeletal sites, termed spondyloarthritis. While it is debated whether disease onset is primarily driven by autoimmune or autoinflammatory processes, what is certain is that both innate and adaptive immune responses orchestrate local and systemic inflammation, which leads to chronic pain and immobility. Immune checkpoint signals are one key player in keeping the immune system in check and in balance, but their role in disease pathogenesis is still rather elusive. Therefore, we ran a MEDLINE search utilizing the PubMed platform for a variety of immune checkpoint signals in regard to ankylosing spondylitis. In this review, we summarize the experimental and genetic data available and evaluate the relevance of immune checkpoint signalling in the pathogenesis of ankylosing spondylitis. Markers such as PD-1 and CTLA-4 have been extensively studied and facilitate the concept of an impaired negative immune regulation in ankylosing spondylitis. Other markers are either neglected completely or insufficiently examined, and the data is conflicting. Still, some of those markers remain interesting targets to decipher the pathogenesis of ankylosing spondylitis and to develop new treatment strategies.

PEG-Sheddable Nanodrug Remodels Tumor Microenvironment to Promote Effector T Cell Infiltration and Revise Their Exhaustion for Breast Cancer Immunotherapy

Low infiltration of cytotoxic T lymphocytes and their exhaustion manifest the two concurrent main hurdles for achieving effective tumor immunotherapy of triple-negative breast cancer. It is found that Galectin-9 blockage can revise the exhaustion of effector T cells, meanwhile the repolarization of protumoral M2 tumor-associated macrophages (TAMs) into tumoricidal M1-like ones can recruit effector T cells infiltrating into tumor to boost immune responses. Herein, a sheddable PEG-decorated and M2-TAMs targeted nanodrug incorporating Signal Transducer and Activator of Transcription 6 inhibitor (AS) and anti-Galectin-9 antibody (aG-9) is prepared. The nanodrug responds to acidic tumor microenvironment (TME) with the shedding of PEG corona and the release of aG-9, exerting local blockade of PD-1/Galectin-9/TIM-3 interaction to augment effector T cells via exhaustion reversing. Synchronously, targeted repolarization of M2-TAMs into M1 phenotype by AS-loaded nanodrug is achieved, which promotes tumor infiltration of effector T cells and thus synergizes with aG-9 blockade to boost the therapeutic efficacy. Besides, the PEG-sheddable approach endows nanodrug with stealth ability to reduce immune-related adverse effects caused by AS and aG-9. This PEG sheddable nanodrug holds the potential to reverse the immunosuppressive TME and increase effector T cell infiltration, which dramatically enhances immunotherapy in highly malignant breast cancer.

Abnormal DNA methylation analysis of leucine-rich glioma-inactivated 1 antibody encephalitis reveals novel methylation-driven genes related to prognostic and clinical features

BACKGROUND

Aberrant DNA methylation occurs commonly during pathogenesis of neuroimmunological diseases and is of clinical value in various encephalitis subtypes. However, knowledge of the impact of DNA methylation changes on pathogenesis of leucine-rich glioma-inactivated 1 (LGI1) antibody encephalitis remains limited.

METHODS

A total of 44 cytokines and 10 immune checkpoint moleculars (ICMs) in the serum of patients with LGI1 encephalitis and healthy donors (HDs) were measured to evaluate the association of them with clinical parameters. Genome-wide DNA methylation profiles were performed in peripheral blood mononuclear cell (PBMC) from LGI1 encephalitis patients and HDs using reduced representation bisulfite sequencing (RRBS) and validated for the methylation status by pyrosequencing. MicroRNA profiles were acquired in serum exosome by small RNA sequencing. Targeted cytokines expression was assessed at the presence or absence of miR-2467-5p in PBMCs and the culture media, and the binding of miR-2467-5p and its targeted genes was validated by luciferase assay.

RESULTS

There existed significant difference in 22 cytokines/chemokines and 6 ICMs between LGI1 encephalitis patients and HDs. Decreased PDCD1 with increased ICAM1 could predict unfavorable prognosis in one-year follow-up for LGI1 encephalitis patients. Fifteen of cytokines/chemokines and ICMs presented DNA-methylated changes in the promoter and gene body using RRBS in which five were verified as methylation status by pyrosequencing, and the methylation level of CSF3, CCL2, and ICAM1 was conversely associated with their expression in PBMCs. By combining RRBS data with exosome-derived microRNA sequencing, we found that hypomethylated-driven hsa-miR-2467-5p presented elevated expression in serum exosomes and PBMCs in LGI1 encephalitis. Mechanically, miR-2467-5p significantly induced reduced expression of CSF3 and PDCD1 by binding with their 3`UTR while enhanced CCL15 expression, but not significantly correlated with peripheral blood CD19 + B cell proportion of LGI1 encephalitis patients.

CONCLUSIONS

Our results provided convincing evidence for DNA methylation changes, microRNA profiles in serum exosome for LGI1 encephalitis, and we also identified several novel cytokines related to clinical features in which some represented epigenetic modification of methylated-driven pattern and microRNA modulation. Our study contributed to develop treatment for epigenetic pathogenesis in LGI1 encephalitis.

Presence of PD-1 similarity genes in monocytes may promote the development of type 1 diabetes mellitus and poor prognosis of pancreatic cancer

INTRODUCTION

To identify proteins and corresponding genes that share sequential and structural similarity with programmed cell death protein-1 (PD-1) in patients with type 1 diabetes mellitus (T1DM) via bioinformatics analysis.

RESEARCH DESIGN AND METHODS

All proteins with immunoglobulin V-set domain were screened in the human protein sequence database, and the corresponding genes were obtained in the gene sequence database. GSE154609 was downloaded from the GEO database, which contained peripheral blood CD14+ monocyte samples from patients with T1DM and healthy controls. The difference result and the similar genes were intersected. Analysis of gene ontology and Kyoto encyclopedia of genes and genomes pathways was used to predict potential functions using the R package 'cluster profiler'. The expression differences of intersected genes were analyzed in The Cancer Genome Atlas pancreatic cancer dataset and GTEx database using t-test. The correlation between the overall survival and disease-free progression of patients with pancreatic cancer was analyzed using Kaplan-Meier survival analysis.

RESULTS

2068 proteins with immunoglobulin V-set domain similar to PD-1 and 307 corresponding genes were found. 1705 upregulated differentially expressed genes (DEGs) and 1335 downregulated DEGs in patients with T1DM compared with healthy controls were identified. A total of 21 genes were overlapped with the 307 PD-1 similarity genes, including 7 upregulated and 14 downregulated. Of these, mRNA levels of 13 genes were significantly increased in patients with pancreatic cancer. High expression of MYOM3 and HHLA2 was significantly correlated with shorter overall survival of patients with pancreatic cancer, while high expression of FGFRL1, CD274, and SPEG was significantly correlated with shorter disease-free survival of patients with pancreatic cancer.

CONCLUSIONS

Genes encoding immunoglobulin V-set domain similar to PD-1 may contribute to the occurrence of T1DM. Of these genes, MYOM3 and SPEG may serve as potential biomarkers for the prognosis of pancreatic cancer.

Exploring Gene Expression Profiles in Primary Central Nervous System Vasculitis

OBJECTIVE

This study was undertaken to explore the gene expression profile of primary central nervous system vasculitis (PCNSV).

METHODS

Brain specimens of 4 patients with granulomatous vasculitis (GV), 5 with lymphocytic vasculitis (LV), 4 with amyloid β-related angiitis (ABRA), and 4 normal controls were studied. RNA-sequencing was performed using the Illumina Hiseq-4,000 platform and the Illumina TruSeq Total-RNA library. Student t test and false discovery rate tests were performed for each of the differentially expressed transcripts. Ingenuity Pathway Analysis was used for the pathway expression analysis. CIBERSORT was used to estimate the abundances of different immune cell subsets in the tissues based on gene expression data.

RESULTS

Transcripts differentially expressed between PCNSV and normal brain indicated that endosomal, mitochondrial, and ribosome dysfunction, alterations in protein synthesis, and noncoding RNAs might be involved in PCNSV. Pathway analysis revealed the activation of dendritic cell maturation and antigen processing as well as neuroinflammation in PCNSV versus normal brain, whereas oxidative phosphorylation was inhibited. CIBERSORT estimation of immune cell subsets suggested that activated NK cells, M1 macrophages, memory B cells, and follicular helper T cells were likely to be more prevalent in PCNSV samples. Naïve CD4 T cells and monocytes were mainly estimated to be present in GV and ABRA. Plasma cell and γδ T-cell signatures were mainly found in LV and normal brain. GV showed higher levels of genes associated with macrophage activities and T cells. ABRA showed higher levels of long noncoding RNAs and miR-616. LV showed higher levels of genes encoding immunoglobulins.

INTERPRETATION

RNA sequencing confirmed PCNSV heterogeneity. ANN NEUROL 2023;93:120-130.

Mucocutaneous adverse events to immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy. Since the approval of ipilimumab in 2011, a total of nine ICIs have gained indications for various solid and hematologic malignancies. The expanding use of ICIs in oncology underscores the need for diagnosis and treatment expertise in immune related adverse events (irAE). Cutaneous toxicities are the earliest and most common irAE in this class of therapy. In addition to the more frequent reactions including vitiligo, lichenoid dermatitis, psoriasiform dermatitis, other less common skin toxicities including bullous dermatoses, neutrophilic dermatoses, and autoimmune dermato-rheumatologic diseases have been reported. Even though less than 3% of cutaneous irAEs (irCAEs) are classified as grade 3 or higher events, irCAEs can greatly impact quality of life. Appropriate management of irCAEs is critical to avoid unwarranted interruptions or discontinuation of lifesaving immunotherapy.

Bridging the Gap: Connecting the Mechanisms of Immune-Related Adverse Events and Autoimmunity Through PD-1

The emergence of anti-cytotoxic T-lymphocyte antigen 4 (anti-CTLA-4), anti-programmed cell death 1 ligand (anti-PD-1), and anti-PD-L1 antibodies as immune checkpoint inhibitors (ICIs) revolutionized the treatment of numerous types of tumors. These antibodies, both alone and in combination, provide great clinical efficacy as evidenced by tumor regression and increased overall patients' survival. However, with this success comes multiple challenges. First, while patients who respond to ICIs have outstanding outcomes, there remains a large proportion of patients who do not respond at all. This all-or-none response has led to looking downstream of programmed cell death 1 (PD-1) for additional therapeutic targets and for new combination therapies. Second, a majority of patients who receive ICIs go on to develop immune-related adverse events (irAEs) characterized by end-organ inflammation with T-cell infiltrates. The hallmarks of these clinically observed irAEs share many similarities with primary autoimmune diseases. The contribution of PD-1 to peripheral tolerance is a major mechanism for protection against expansion of self-reactive T-cell clones and autoimmune disease. In this review, we aim to bridge the gaps between our cellular and molecular knowledge of PD-1 signaling in T cells, ICI-induced irAEs, and autoimmune diseases. We will highlight shared mechanisms and the potential for new therapeutic strategies.

Targeting LAG3/GAL-3 to overcome immunosuppression and enhance anti-tumor immune responses in multiple myeloma

Immune profiling in patients with monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), and multiple myeloma (MM) provides the framework for developing novel immunotherapeutic strategies. Here, we demonstrate decreased CD4⁺ Th cells, increased Treg and G-type MDSC, and upregulation of immune checkpoints on effector/regulatory and CD138⁺ cells in MM patients, compared MGUS/SMM patients or healthy individuals. Among the checkpoints profiled, LAG3 was most highly expressed on proliferating CD4⁺ Th and CD8⁺ Tc cells in MM patients BMMC and PBMC. Treatment with antibody targeting LAG3 significantly enhanced T cells proliferation and activities against MM. XBP1/CD138/CS1-specific CTL generated in vitro displayed anti-MM activity, which was further enhanced following anti-LAG3 treatment, within the antigen-specific memory T cells. Treg and G-type MDSC weakly express LAG3 and were minimally impacted by anti-LAG3. CD138⁺ MM cells express GAL-3, a ligand for LAG3, and anti-GAL-3 treatment increased MM-specific responses, as observed for anti-LAG3. Finally, we demonstrate checkpoint inhibitor treatment evokes non-targeted checkpoints as a cause of resistance and propose combination therapeutic strategies to overcome this resistance. These studies identify and validate blockade of LAG3/GAL-3, alone or in combination with immune strategies including XBP1/CD138/CS1 multipeptide vaccination, to enhance anti-tumor responses and improve patient outcome in MM.

Lupus susceptibility region containing CTLA4 rs17268364 functionally reduces CTLA4 expression by binding EWSR1 and correlates IFN-α signature

Background

Dysregulation of T cells mediated immune responses is a hallmark in the development of systemic lupus erythematosus (SLE). Recent genome wide association study (GWAS) revealed the genetic contribution of variants located in the cytotoxic T lymphocyte-associated protein-4 (CTLA4)-inducible T cell co-stimulator (ICOS) intergenic region to SLE susceptibility. Our aim is to find a functional variant in this region.

Methods

The genetic association results in the CTLA4-ICOS region from previous GWAS were adopted to select the potential variant which was further replicated in two independent cohorts (Henan cohort 2053 SLE patients and 1845 healthy controls, Beijing cohort 2303 SLE patients and 19,262 healthy). In order to explore the functional significance in SLE, bioinformatics with validation experiments (including electrophoretic mobility shift assay and luciferase reporter assay) and mRNA expression analysis were also performed.

Results

A variant located in the CTLA4-ICOS intergenic region, rs17268364, was associated with susceptibility to SLE patients in Chinese populations (risk allele, p_meta = 7.02×10⁻¹¹, OR 1.19, 95%CI 1.13–1.26). The bioinformatics suggested that rs17268364 might affect the expression of CTLA4, not ICOS. The rs17268364 risk G allele containing sequence reduced the expression of the reporter gene by binding transcriptional repressor Ewing sarcoma breakpoint region 1 (EWSR1). Following genotype-mRNA expression, the analysis also showed the risk allele of rs17268364 was associated with low CTLA4 expression in lupus nephritis (LN) patients. Healthy individuals carrying rs17268364 risk G allele was significantly correlated with higher levels of IFN-α signature including increased lymphocyte antigen 6E (LY6E) (p=0.031), interferon-stimulated gene 15 (ISG15) (p=0.038), interferon regulatory factor 9 (IRF9) (p=0.028), and interferon regulatory factor 5 (IRF5) (p=0.040) mRNA expression.

Conclusions

The present study confirmed the functional role of rs17268364 in the CTLA4-ICOS intergenic region that increased SLE susceptibility in the Chinese population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02664-y.

Therapeutic Development Based on the Immunopathogenic Mechanisms of Psoriasis

Psoriasis, a complex inflammatory autoimmune skin disorder that affects 2–3% of the global population, is thought to be genetically predetermined and induced by environmental and immunological factors. In the past decades, basic and clinical studies have significantly expanded knowledge on the molecular, cellular, and immunological mechanisms underlying the pathogenesis of psoriasis. Based on these pathogenic mechanisms, the current disease model emphasizes the role of aberrant Th1 and Th17 responses. Th1 and Th17 immune responses are regulated by a complex network of different cytokines, including TNF-α, IL-17, and IL-23; signal transduction pathways downstream to the cytokine receptors; and various activated transcription factors, including NF-κB, interferon regulatory factors (IRFs), and signal transducer and activator of transcriptions (STATs). The biologics developed to specifically target the cytokines have achieved a better efficacy and safety for the systemic management of psoriasis compared with traditional treatments. Nevertheless, the current therapeutics can only alleviate the symptoms; there is still no cure for psoriasis. Therefore, the development of more effective, safe, and affordable therapeutics for psoriasis is important. In this review, we discussed the current trend of therapeutic development for psoriasis based on the recent discoveries in the immune modulation of the inflammatory response in psoriasis.

Thromboembolic events associated with immune checkpoint inhibitors: A real-world study of data from the food and drug administration adverse event reporting system (FAERS) database

BACKGROUND

Although there have been a few studies reporting thromboembolic events (TEEs) in patients treated with immune checkpoint inhibitors (ICIs), the detailed profile of the TEEs and the prothrombotic effects of ICIs remain mostly unknown.

METHODS

Data from January 2004 to December 2019 in the FAERS database were retrieved. We investigated the clinical characteristics of the TEEs and conducted disproportionality analysis by using reporting odds ratios (ROR) to compare ICIs with the full database and other anti-cancer agents.

RESULTS

We identified 1855 reports of TEEs associated with ICIs. Affected patients tended to be male (59.68%) and older than 65 (47.12%). The case-fatality rate of the reported TEEs was high (38%). The median time to onset (TTO) of all cases was 42 (interquartile range [IQR] 15-96) days and the median TTO of fatal cases (31 [IQR 13-73] days) was significantly shorter than non-fatal cases (50 [IQR 20-108] days, p = 0.000002). ICIs showed increased risks of VTE (ROR 2.81, 95% CI 2.69-2.95) and ATE (ROR 1.44, 95% CI 1.37-1.52) compared with the full database. Compared with protein kinase inhibitors, ICIs showed an increased risk of VTE (ROR 1.23, 95% CI 1.17-1.29), but only anti-PD-L1 showed an increased risk of cerebral ATE (ROR 1.38, 95% CI 1.08-1.76). Compared with chemotherapy, ICIs showed an increased risk of PE (ROR 1.14, 95% CI 1.07-1.21).

CONCLUSIONS

Our study suggested ICIs tend to increase risks of VTE and ATE. The poor clinical outcome and early onset of these events should attract clinical attention.

Immune checkpoint inhibitor treatment and atherosclerotic cardiovascular disease: an emerging clinical problem

Antibody-mediated blockade of co-inhibitory molecules such as cytotoxic T lymphocyte-associated protein 4, PD1 and PDL1 elicits potent antitumor responses and improves the prognosis of many patients with cancer. As these immune checkpoint inhibitors (ICIs) are increasingly prescribed to a diverse patient population, a broad range of adverse effects is emerging. Atherosclerosis, a lipid-driven chronic inflammatory disease of the large arteries, may be aggravated by ICI treatment. In this review, we discuss recent clinical studies that analyze the correlation between ICI use and atherosclerotic cardiovascular disease (CVD). Indeed, several studies report an increased incidence of atherosclerotic CVD after ICI administration, with the occurrence of pathologies such as myocardial infarction, ischemic stroke and coronary artery disease significantly higher after ICI use. Increased awareness and better monitoring of ICI-treated patients can elucidate risk factors that contribute to ICI-induced aggravation of atherosclerosis and identify promising treatment strategies. For now, optimal cardiovascular risk assessment is required to protect ICI-receiving patients and long-term survivors of cancer from the detrimental effects of ICI therapy on atherosclerotic CVD.

Gut Microbiota in Lupus: a Butterfly Effect?

PURPOSE OF REVIEW

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease that typically displays chronic inflammatory tissue damage and miscellaneous circulatory autoantibodies, as well as distinctive type 1 interferon signatures. The etiology of SLE is unclear and currently is attributed to genetic predisposition and environmental triggers. Gut microbiota has recently been considered a critical environmental pathogenic factor in immune-related disorders, and studies are ongoing to uncover the key pathogens and the imputative mechanisms. Fundamental advancements on the role of the microbiota in SLE pathology have been achieved in recent years and are summarized in this review.

RECENT FINDINGS

Recent findings suggested that gut commensals could propagate autoimmunity via molecular mimicry in which ortholog-carrying microbes cross-activate autoreactive T/B cells and trigger the response against host autoantigens, or via bystander activation by stimulating antigen-presenting cells that present autoantigens and enhancing the expression of co-stimulatory molecules and cytokines, thus leading to the loss of self-tolerance and the production of autoantibodies. Additionally, the break of gut barrier and the translocation of gut commensals to inner organs can trigger immune dysregulation and inappropriate systemic inflammation. All these microbiota-mediated mechanisms could contribute to lupus immunopathogenesis and promote disease development in susceptible individuals. Evidence of the causative role of disturbed gut microbiome in SLE is still limited, and the related molecular mechanisms and pathways are largely elusive. However, the modification of gut microbiota, such as pathobiont vaccine, special diet, restricted consortium transplantation, as well as regulatory metabolites supplementation, might be promising strategies for lupus prophylaxis and treatment.

Programmed death ligand-1 (PD-L1) as a predictive marker for immunotherapy in solid tumours: a guide to immunohistochemistry implementation and interpretation

Immunotherapy with checkpoint inhibitors is well established as an effective treatment for non-small cell lung cancer and melanoma. The list of approved indications for treatment with PD-1/PD-L1 checkpoint inhibitors is growing rapidly as clinical trials continue to show their efficacy in patients with a wide range of solid tumours. Clinical trials have used a variety of PD-L1 immunohistochemical assays to evaluate PD-L1 expression on tumour cells, immune cells or both as a potential biomarker to predict response to immunotherapy. Requests to pathologists for PD-L1 testing to guide choice of therapy are rapidly becoming commonplace. Thus, pathologists need to be aware of the different PD-L1 assays, methods of evaluation in different tumour types and the impact of the results on therapeutic decisions. This review discusses the key practical issues relating to the implementation of PD-L1 testing for solid tumours in a pathology laboratory, including evidence for PD-L1 testing, different assay types, the potential interchangeability of PD-L1 antibody clones and staining platforms, scoring criteria for PD-L1, validation, quality assurance, and pitfalls in PD-L1 assessment. This review also explores PD-L1 IHC in solid tumours including non-small cell lung carcinoma, head and neck carcinoma, triple negative breast carcinoma, melanoma, renal cell carcinoma, urothelial carcinoma, gastric and gastroesophageal carcinoma, colorectal carcinoma, hepatocellular carcinoma, and endometrial carcinoma. The review aims to provide pathologists with a practical guide to the implementation and interpretation of PD-L1 testing by immunohistochemistry.