The immunoinhibitory PD-1/PD-L1 pathway in inflammatory blood vessel disease

Exosomal long non-coding RNAs in lung cancer: A review

Lung cancer is one of the most threatening malignancies among the different kinds of tumors. The incidence and mortality rate are increasing especially in male. Advances in diagnosis and treatment have been achieve in recent years. However, the lung tumor cells also developing chemo- and radio-resistance. Novel approaches and new treatments are stilled needed to develop for early diagnosis and treatment. Recently, long non-coding RNAs (lncRNAs) original exosomes were proved different expression in lung tumor, which mediate multiple biological processes and is responsible for tumor proliferation and metastasis. In this review, we focus on the emerging roles of both lncRNAs and exosomal lncRNAs in lung cancer and their roles on angiogenesis, metastasis, diagnosis, drug resistance, and immune regulation of lung cancer. Exosome lncRNAs were proved to serve as regulatory factors for gene expression, mediating intercellular communication, and participating in the occurrence and development of various diseases. In addition, exosomes lnc RNA has advantages on the early diagnosis of lung cancer, tumor cell metastasis, drug resistance, and immune regulation. Exosome lncRNAs an provide some unique ideas on how to improve the efficiency of diagnosis and treatment of lung cancer in the future.

PD-1 immunology in the kidneys: a growing relationship

In recent years, knowledge regarding immune regulation has expanded rapidly, and major advancements have been made in immunotherapy for immune-associated disorders, particularly cancer. The programmed cell death 1 (PD-1) pathway is a cornerstone in immune regulation. It comprises PD-1 and its ligands mediating immune tolerance mechanisms and immune homeostasis. Accumulating evidence demonstrates that the PD-1 axis has a crucial immunosuppressive role in the tumor microenvironment and autoimmune diseases. PD-1 receptors and ligands on immune cells and renal parenchymal cells aid in maintaining immunological homeostasis in the kidneys. Here, we present a comprehensive review of PD-1 immunology in various kidney disorders, including renal cell carcinoma, glomerulonephritis, kidney transplantation, renal aging, and renal immune-related adverse events secondary to PD-1 immunotherapy.

Inhibitory immune checkpoints suppress the surveillance of senescent cells promoting their accumulation with aging and in age-related diseases

The accumulation of pro-inflammatory senescent cells within tissues is a common hallmark of the aging process and many age-related diseases. This modification has been called the senescence-associated secretory phenotype (SASP) and observed in cultured cells and in cells isolated from aged tissues. Currently, there is a debate whether the accumulation of senescent cells within tissues should be attributed to increased generation of senescent cells or to a defect in their elimination from aging tissues. Emerging studies have revealed that senescent cells display an increased expression of several inhibitory immune checkpoint ligands, especially those of the programmed cell death protein-1 (PD-1) ligand-1 (PD-L1) proteins. It is known that the PD-L1 ligands, especially those of cancer cells, target the PD-1 receptor of cytotoxic CD8+ T and natural killer (NK) cells disturbing their functions, e.g., evoking a decline in their cytotoxic activity and promoting their exhaustion and even apoptosis. An increase in the level of the PD-L1 protein in senescent cells was able to suppress their immune surveillance and inhibit their elimination by cytotoxic CD8+ T and NK cells. Senescent cells are known to express ligands for several inhibitory immune checkpoint receptors, i.e., PD-1, LILRB4, NKG2A, TIM-3, and SIRPα receptors. Here, I will briefly describe those pathways and examine whether these inhibitory checkpoints could be involved in the immune evasion of senescent cells with aging and age-related diseases. It seems plausible that an enhanced inhibitory checkpoint signaling can prevent the elimination of senescent cells from tissues and thus promote the aging process.

Correlation between PD-1/PD-L1 and RANKL/OPG in chronic apical periodontitis model of Sprague-Dawley rats

Chronic apical periodontitis (CAP) is characterized by inflammation and destruction of the apical periodontium that is of pulpal origin, appearing as an apical radiolucent area, and does not produce clinical symptoms. Little is known about whether the PD-1/PD-L1 ratio is associated with the balance between RANKL and OPG in CAP. The relationship between PD-1/PD-L1 and RANKL/OPG in CAP is investigated in this study. A CAP rat model was established using Sprague-Dawley rats. The pulp chambers were exposed to the oral cavity to allow bacterial contamination. The apical tissues of the bilateral mandibular first molars were analyzed for histological morphology using hematoxylin and eosin (H&E) staining. Immunohistochemistry and qRT-PCR were used to determine the expression of PD-1, PD-L1, OPG, and RANKL mRNA and proteins in periapical tissues and mandibular samples, respectively. The radiological images indicated a poorly defined low-density shadow and alveolar bone resorption after periodontitis induction. Histological analysis revealed an infiltration of inflammatory cells and alveolar bone resorption in the periapical tissues. Mandibular mRNA and periapical protein expression of PD-1, PD-L1, and RANKL was upregulated 7-28 days after periodontitis induction, while the expression of OPG was downregulated. No significant relationship was observed between PD-1/PD-L1 and RANKL/OPG at either mRNA or protein levels in CAP. There is an increased expression of PD-1, PD-L1, and RANKL and a decreased expression of OPG, indicating progression of CAP.

Evaluation of the effectiveness and safety of combining PD-1/PD-L1 inhibitors with anti-angiogenic agents in unresectable hepatocellular carcinoma: a systematic review and meta-analysis

BACKGROUND

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality globally, particularly when diagnosed at an unresectable stage. Traditional treatments for advanced HCC have limited efficacy, prompting the exploration of combination therapies. This systematic review and meta-analysis evaluate the effectiveness and safety of combining PD-1/PD-L1 inhibitors with anti-angiogenic agents in patients with unresectable HCC.

METHODS

A comprehensive literature search was conducted in PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science, including studies up to June 2024. Randomized controlled trials (RCTs) comparing combination therapy (PD-1/PD-L1 inhibitors with anti-angiogenic agents) to monotherapy or standard treatments in unresectable HCC patients were included. Data were synthesized using random-effects models, with pooled hazard ratios (HRs) for overall survival (OS) and progression-free survival (PFS), and risk ratios (RRs) for objective response rate (ORR) and adverse events (AEs).

RESULTS

Five Phase III RCTs involving 1515 patients were included. Combination therapy significantly improved OS (HR: 0.71, 95% CI: 0.60-0.85) and PFS (HR: 0.64, 95% CI: 0.53-0.77) compared to monotherapy or standard treatments. The pooled OR for ORR was 1.27 (95% CI: 1.57-2.11), indicating a higher response rate with combination therapy. However, the risk of AEs was also higher in the combination therapy group (RR: 1.04, 95% CI: 1.02-1.06). Subgroup analyses revealed consistent benefits across different types of PD-1/PD-L1 inhibitors and anti-angiogenic agents, with no significant publication bias detected.

CONCLUSIONS

The combination of PD-1/PD-L1 inhibitors with anti-angiogenic agents offers significant benefits in improving OS and PFS in patients with unresectable HCC, although it is associated with an increased risk of adverse events.

Tumor necrosis factor receptor 2 promotes endothelial cell-mediated suppression of CD8+ T cells through tuning glycolysis in chemoresistance of breast cancer

BACKGROUND

T cells play a pivotal role in chemotherapy-triggered anti-tumor effects. Emerging evidence underscores the link between impaired anti-tumor immune responses and resistance to paclitaxel therapy in triple-negative breast cancer (TNBC). Tumor-related endothelial cells (ECs) have potential immunoregulatory activity. However, how ECs regulate T cell activity during TNBC chemotherapy remains poorly understood.

METHODS

Single-cell analysis of ECs in patients with TNBC receiving paclitaxel therapy was performed using an accessible single-cell RNA sequencing (scRNA-seq) dataset to identify key EC subtypes and their immune characteristics. An integrated analysis of a tumor-bearing mouse model, immunofluorescence, and a spatial transcriptome dataset revealed the spatial relationship between ECs, especially Tumor necrosis factor receptor (TNFR) 2+ ECs, and CD8+ T cells. RNA sequencing, CD8+ T cell proliferation assays, flow cytometry, and bioinformatic analyses were performed to explore the immunosuppressive function of TNFR2 in ECs. The downstream metabolic mechanism of TNFR2 was further investigated using RNA sequencing, cellular glycolysis assays, and western blotting.

RESULTS

In this study, we identified an immunoregulatory EC subtype, characterized by enhanced TNFR2 expression in non-responders. By a mouse model of TNBC, we revealed a dynamic reduction in the proportion of the CD8+ T cell-contacting tumor vessels that could co-localize spatially with CD8+ T cells during chemotherapy and an increased expression of TNFR2 by ECs. TNFR2 suppresses glycolytic activity in ECs by activating NF-κB signaling in vitro. Tuning endothelial glycolysis enhances programmed death-ligand (PD-L) 1-dependent inhibitory capacity, thereby inducing CD8+ T cell suppression. In addition, TNFR2+ ECs showed a greater spatial affinity for exhausted CD8+ T cells than for non-exhausted CD8+ T cells. TNFR2 blockade restores impaired anti-tumor immunity in vivo, leading to the loss of PD-L1 expression by ECs and enhancement of CD8+ T cell infiltration into the tumors.

CONCLUSIONS

These findings reveal the suppression of CD8+ T cells by ECs in chemoresistance and indicate the critical role of TNFR2 in driving the immunosuppressive capacity of ECs via tuning glycolysis. Targeting endothelial TNFR2 may serve as a potent strategy for treating TNBC with paclitaxel.

Androgen aggravates aortic aneurysms via suppression of PD-1 in mice

Androgen has long been recognized for its pivotal role in the sexual dimorphism of cardiovascular diseases, including aortic aneurysms (AAs), a devastating vascular disease with a higher prevalence and fatality rate in men than in women. However, the mechanism by which androgen mediates AAs is largely unknown. Here, we found that male, not female, mice developed AAs when exposed to aldosterone and high salt (Aldo-salt). We revealed that androgen and androgen receptors (ARs) were crucial for this sexually dimorphic response to Aldo-salt. We identified programmed cell death protein 1 (PD-1), an immune checkpoint, as a key link between androgen and AAs. Furthermore, we demonstrated that administration of anti-PD-1 Ab and adoptive PD-1-deficient T cell transfer reinstated Aldo-salt-induced AAs in orchiectomized mice and that genetic deletion of PD-1 exacerbated AAs induced by a high-fat diet and angiotensin II (Ang II) in nonorchiectomized mice. Mechanistically, we discovered that the AR bound to the PD-1 promoter to suppress the expression of PD-1 in the spleen. Thus, our study unveils a mechanism by which androgen aggravates AAs by suppressing PD-1 expression in T cells. Moreover, our study suggests that some patients with cancer might benefit from screenings for AAs during immune checkpoint therapy.

Relapses in giant cell arteritis: Updated review for clinical practice

Giant cell arteritis (GCA), the most common primary vasculitis in adults, is a granulomatous systemic vasculitis usually affecting the aorta and its major branches, particularly the carotid and vertebral arteries. Although remission can be achieved in most patients with GCA using high-dose glucocorticoids (GC), relapses are frequent, occurring in >40% of GC-only treated patients, mostly during the first two years after diagnosis. Relapsing courses lead to high GC exposure, increasing the risk of treatment-related adverse effects. Although tocilizumab is an efficacious GC-sparing therapy that allows increased sustained remission and reduced cumulative GC doses, relapses are common after drug discontinuation. This narrative review examines the most relevant features of relapses in GCA, including its definition, classification, frequency, clinical, laboratory, and imaging characteristics, chronology, probable pathophysiology, and predictive factors. In addition, we discuss treatment options for relapsing patients and the effect of relapses on patient outcomes.

A scoping review of vasculitis as an immune-related adverse event from checkpoint inhibitor therapy of cancer: Unraveling the complexities at the intersection of immunology and vascular pathology

BACKGROUND/PURPOSE

Vasculitis as an immune-related adverse event (irAE) from checkpoint inhibitor therapy (ICI) to treat cancer is a rare clinical event, and little is known regarding its nosology, clinical manifestations, or response to treatment and outcomes.

METHODS

To address these gaps, we used the Preferred Reporting Items for Systemic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) framework to further define this complication. Two independent PUBMED searches in September and November of 2022 revealed 127 publications with 37 excluded from title by relevance, 43 excluded by article type, and 23 excluded due to lack of biopsy results, or biopsy negative for vasculitis. Twenty-nine documented cases from 24 publications were included for final analysis. Basic demographics, ICI details, timing of onset of vasculitis symptoms, irAE treatment and outcomes were collected. The vasculitides were classified using 2022 ACR/EULAR Vasculitis Classification Criteria as well as 2012 Revised Chapel-Hill Nomenclature. Adaptations from Naidoo et al. 2023 [1] consensus definitions for irAEs were used and efforts were made to classify steroid-responsive versus unresponsive irAEs.

RESULTS

Of the 29 cases reviewed, the average age of patients was 62.1 ± 11.0, composed of 58.6 % (n = 17) male and 41.3 % (n = 12) female. Prominent cancer types were lung cancer (41.4 %; n = 12), melanoma (41.4 %; n = 12), and renal cancer (10.3 %; n = 3), with majority being stage 4 (75.9 %, n = 22) and stage 3 (10.3 %, n = 3). Only 8 cases met the ACR/EULAR criteria, and by Chapel-Hill Nomenclature, approximately a third were small-vessel vasculitis (31.0 %; n = 9) with n = 4 positive for ANCA. Most biopsies were taken from the skin (37.9 %, n = 11) and kidney (24.1 %, n = 7). Patients were either treated with single (65.5 %, n = 19), dual (17.2 %; n = 5), or sequential (17.2 %; n = 5) ICI regimen which included anti-PD-1 therapy in all but one case, with mean of 8.7 ± 10.5 cycles received. Mean time to onset of symptoms from start of ICI was 7.2 ± 7.8 months, with 55.2 % occurring >3 months since the initial immunotherapy. Vasculitis treatment included glucocorticoids in 96 % of cases and immunotherapy was often discontinued (44.8 %; n = 13). Clinical improvement of irAE was documented in 86.2 % (n = 25). Data were missing in terms of fate of ICI (34.5 %; n = 10) and tumor outcomes (41.4 %; n = 12). Cancer progressed in 20.7 % (n = 6), stable in 34.5 % (n = 10) cases, and 6 patients died of all-causes.

CONCLUSION

Vasculitis as an irAE appears clinically heterogeneous and rare. Among reported cases with adequate documentation, vasculitis is of delayed onset following the initiation of immunotherapy. Outcomes of ICI-vasculitis were generally favorable, responding to glucocorticoids and immunotherapy withdrawal. There is an urgent need for more standardized reporting of rare irAEs such as vasculitis to clarify clinical risks, classification, relationship to immunotherapy and outcomes.

The role of the immunosuppressive PD-1/PD-L1 checkpoint pathway in the aging process and age-related diseases

The accumulation of senescent cells within tissues is a hallmark of the aging process. Senescent cells are also commonly present in many age-related diseases and in the cancer microenvironment. The escape of abnormal cells from immune surveillance indicates that there is some defect in the function of cytotoxic immune cells, e.g., CD8+ T cells and natural killer (NK) cells. Recent studies have revealed that the expression of programmed death-ligand 1 (PD-L1) protein is abundantly increased in senescent cells. An increase in the amount of PD-L1 protein protects senescent cells from clearance by the PD-1 checkpoint receptor in cytotoxic immune cells. In fact, the activation of the PD-1 receptor suppresses the cytotoxic properties of CD8+ T and NK cells, promoting a state of immunosenescence. The inhibitory PD-1/PD-L1 checkpoint pathway acts in cooperation with immunosuppressive cells; for example, activation of PD-1 receptor can enhance the differentiation of regulatory T cells (Treg), myeloid-derived suppressor cells (MDSC), and M2 macrophages, whereas the cytokines secreted by immunosuppressive cells stimulate the expression of the immunosuppressive PD-L1 protein. Interestingly, many signaling pathways known to promote cellular senescence and the aging process are crucial stimulators of the expression of PD-L1 protein, e.g., epigenetic regulation, inflammatory mediators, mTOR-related signaling, cGAS-STING pathway, and AhR signaling. It seems that the inhibitory PD-1/PD-L1 immune checkpoint axis has a crucial role in the accumulation of senescent cells and thus it promotes the aging process in tissues. Thus, the blockade of the PD-1/PD-L1 checkpoint signaling might be a potential anti-aging senolytic therapy. KEY MESSAGES: Senescent cells accumulate within tissues during aging and age-related diseases. Senescent cells are able to escape immune surveillance by cytotoxic immune cells. Expression of programmed death-ligand 1 (PD-L1) markedly increases in senescent cells. Age-related signaling stimulates the expression of PD-L1 protein in senescent cells. Inhibitory PD-1/PD-L1 checkpoint pathway suppresses clearance of senescent cells.

Immune Checkpoint Inhibitor-induced Polymyalgia Rheumatica

Polymyalgia rheumatica (PMR) immune-related adverse events (ICI-PMRs) represent a novel, distinct entity, despite many clinical, laboratory, and imaging similarities to classical PMR. Important questions remain in differentiating ICI-PMR from classical PMR, as well as other immune-related adverse events and PMR mimics. Despite this, ICI-PMR currently takes treatment cues from classical PMR, albeit with considerations relevant to cancer immunotherapy. Comparisons between ICI-PMR and classical PMR may provide further bidirectional insights, especially given that important questions remain unanswered about both diseases. The cause of classical PMR remains poorly understood, and ICI-PMR may represent a model of induced PMR, with important therapeutic implications.

Comparative analysis of calcified soft tissues revealed shared deregulated pathways

Introduction

Calcification of soft tissues is a common age-related pathology that primarily occurs within vascular tissue. The mechanisms underlying pathological calcification in humans and tissue specificity of the process is still poorly understood. Previous studies examined calcified tissues on one to one basis, thus preventing comparison of deregulated pathways across tissues.

Purpose

This study aimed to establish common and tissue-specific changes associated with calcification in aorta, artery tibial, coronary artery and pituitary gland in subjects from the Genotype-Tissue Expression (GTEx) dataset using its RNA sequencing and histological data.

Methods

We used publicly available data from the GTEx database https://gtexportal.org/home/aboutGTEx. All GTEx tissue samples were derived by the GTEx consorcium from deceased donors, with age from 20 to 79, both men and women. GTEx study authorization was obtained via next-of-kin consent for the collection and banking of de-identified tissue samples for scientific research. Hematoxylin and eosin (H&E) staining of arteries were manually graded based on the presence of calcification on a scale from zero to four, where zero designates absence of calcification and four designates severe calcification. Samples with fat contamination and mislabeled tissues were excluded, which left 430 aorta, 595 artery tibial, 124 coronary artery, and 283 pituitary samples for downstream gene expression analysis. Transcript levels of protein-coding genes were associated with calcification grade using sex, age bracket and cause of death as covariates, and tested for pathway enrichment using gene set enrichment analysis.

Results

We identified calcification deposits in 28 (6.5%) aortas, 121 (20%), artery tibials, 54 (43%), coronary arteries, and 24 (8%) pituitary glands of GTEx subjects. We observed an age-dependent increase in incidence of calcification in all vascular tissues, but not in pituitary. Subjects with calcification in the artery tibial were significantly more likely to have calcification in the coronary artery (OR = 2.56, p = 6.3e-07). Markers of calcification previously established in preclinical and in vitro studies, e.g., BMP2 and RUNX2, were deregulated in the calcified tibial and coronary arteries, confirming the relevance of these genes to human pathology. Differentially expressed genes associated with calcification poorly overlapped across tissues suggesting tissue-specific nuances in mechanisms of calcification. Nevertheless, calcified arteries unanimously down-regulated pathways of intracellular transport and up-regulated inflammatory pathways suggesting these as universal targets for pathological calcification. In particular, PD-1 and PD-L1 genes were up-regulated in calcified tissues but not in the blood of the same subjects, suggesting that localized inflammation contributes to pathological calcification.

Conclusion

Pathological calcification is a prevalent disease of aging that shares little changes in expression in individual genes across tissues. However, our analysis suggests that it potentially can be targeted by alleviating local inflammation of soft tissues.

ER stress modulates the immune regulatory ability in gut M2 cells of patients with ulcerative colitis

This study aims to characterize the impaired immune regulatory function of Mφ obtained from UC patient colon lavage fluid (CLF). Mφs were the largest proportion (21.3 4.0%) of the CLF-derived cellular components. Less abundant and weaker immune suppressive function were observed in M2 Mφs (M2 cells) of the ulcerative colitis (UC) group. High levels of endoplasmic reticulum (ER) stress associated molecules were detected in UC M2 cells. The spliced X box binding protein-1 (XBP1) gene was negatively correlated with programmed death ligand-1 (PD-L1) in UC M2 cells. XBP1 promoted the expression of ring-finger protein 20 (Rnf20) in M2 cells. Rnf20 reduced PD-L1 abundance in UC M2 cells and impaired the immune suppressive ability. Inhibition of Rnf20 restored the immune regulating capacity of M2 cells and suppressed experimental colitis.

Androgen aggravates aortic aneurysms via suppressing PD-1 in mice

Androgen has long been recognized for its pivotal role in the sexual dimorphism of cardiovascular diseases, including aortic aneurysms, a devastating vascular disease with a higher prevalence and mortality rate in men than women. However, the molecular mechanism by which androgen mediates aortic aneurysms is largely unknown. Here, we report that male but not female mice develop aortic aneurysms in response to aldosterone and high salt (Aldo-salt). We demonstrate that both androgen and androgen receptors (AR) are crucial for the sexually dimorphic response to Aldo-salt. We identify T cells expressing programmed cell death protein 1 (PD-1), an immune checkpoint molecule important in immunity and cancer immunotherapy, as a key link between androgen and aortic aneurysms. We show that intraperitoneal injection of anti-PD-1 antibody reinstates Aldo-salt-induced aortic aneurysms in orchiectomized mice. Mechanistically, we demonstrate that AR binds to the PD-1 promoter to suppress its expression in the spleen. Hence, our study reveals an important but unexplored mechanism by which androgen contributes to aortic aneurysms by suppressing PD-1 expression in T cells. Our study also suggests that cancer patients predisposed to the risk factors of aortic aneurysms may be advised to screen for aortic aneurysms during immune checkpoint therapy.

Divergent roles of PD-L1 in immune regulation during ischemia-reperfusion injury

Ischemia-reperfusion (I/R) injury is a type of pathological injury that commonly arises in various diseases. Various forms of immune response are involved in the process of I/R injury. As a member of the B7 costimulatory molecule family, programmed death 1-ligand 1 (PD-L1) is an important target for immune regulation. Therefore, PD-L1 may be implicated in the regulation of I/R injury. This review briefly describes the immune response during I/R injury and how PD-L1 is involved in its regulation by focusing on findings from various I/R models. Despite the limited number of studies in this field of research, PD-L1 has shown sufficient potential as a clinical therapeutic target.

PD-1 Alleviates Cisplatin-Induced Muscle Atrophy by Regulating Inflammation and Oxidative Stress

Skeletal muscle atrophy is an important characteristic of cachexia, which can be induced by chemotherapy and significantly contributes to functional muscle impairment. Inflammation and oxidative stress are believed to play important roles in the muscle atrophy observed in cachexia, but whether programmed cell death protein 1 (PD-1) is affected by this condition remains unclear. PD-1 is a membrane protein that is expressed on the surface of many immune cells and plays an important role in adaptive immune responses and autoimmunity. Thus, we investigated the role and underlying mechanism of PD-1 in cisplatin-induced muscle atrophy in mice. We found that PD-1 knockout dramatically contributed to skeletal muscle atrophy. Mechanistically, we found that E3 ubiquitin-protein ligases were significantly increased in PD-1 knockout mice after cisplatin treatment. In addition, we found that PD-1 knockout significantly exacerbated cisplatin-induced skeletal muscle inflammation and oxidative stress. Moreover, we found that there were significant increases in ferroptosis-related and autophagy-related genes in PD-1 knockout mice after cisplatin treatment. These data indicate that PD-1 plays an important role in cisplatin-induced skeletal muscle atrophy.

Cardiotoxicity associated with immune checkpoint inhibitors: Current status and future challenges

Immune checkpoint inhibitors (ICIs) are the most notable breakthrough in tumor treatment. ICIs has been widely used in tumor patients, but its wide range of immune-related adverse events (irAEs) should not be ignored. irAEs can be involved in any organ system, including immune-related cardiotoxicity. Although the cardiotoxicity induced by immune checkpoint inhibitors is rare, it is extremely lethal and has attracted increasing attention. PD-1 and PD-L1 are expressed in human cardiomyocytes, so the application of PD-1/PDL-1 inhibitors can cause many adverse reactions to the cardiovascular system. This review summarizes the latest epidemiological evidence on the cardiovascular toxicity of programmed cell death protein-1(PD-1)/programmed cell death ligand-1(PD-L1) inhibitors and the clinical manifestations, as well as the potential pathological mechanisms. These updates may provide a novel perspective for monitoring early toxicity and establishing appropriate treatment for patients with ICI-related cardiotoxicity.

[Granulomatous vasculitides and vasculitides with extravascular granulomatosis]

Vasculitides are inflammatory diseases of blood vessels caused by autoimmune or infectious processes, which are associated with alterations and destruction of the vascular wall. From a histopathological point of view, granulomatous vasculitides can be distinguished from necrotizing vasculitides with respect to the pattern of inflammation. Granulomatous vasculitides are characterized by intramural, predominantly lymphohistiocytic infiltrates with the formation of giant cells. They include giant cell arteritis (GCA) and Takayasu arteritis (TAK). By contrast, anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) belongs to the group of necrotizing vasculitides. AAV includes granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). In addition to systemic necrotizing small vessel vasculitis, GPA and EGPA are characterized by extravascular granulomatous necrotizing inflammation mainly affecting the upper and/or lower respiratory tract, in EGPA with eosinophilic infiltrates. These granulomatous lesions are part of the autoimmune process and associated with tissue damage.

The innate face of Giant Cell Arteritis: Insight into cellular and molecular innate immunity pathways to unravel new possible biomarkers of disease

Giant cell arteritis (GCA) is an inflammatory chronic disease mainly occurring in elderly individuals. The pathogenesis of GCA is still far from being completely elucidated. However, in susceptible arteries, an aberrant immune system activation drives the occurrence of vascular remodeling which is mainly characterized by intimal hyperplasia and luminal obstruction. Vascular damage leads to ischemic manifestations involving extra-cranial branches of carotid arteries, mostly temporal arteries, and aorta. Classically, GCA was considered a pathological process resulting from the interaction between an unknown environmental trigger, such as an infectious agent, with local dendritic cells (DCs), activated CD4 T cells and effector macrophages. In the last years, the complexity of GCA has been underlined by robust evidence suggesting that several cell subsets belonging to the innate immunity can contribute to disease development and progression. Specifically, a role in driving tissue damage and adaptive immunity activation was described for dendritic cells (DCs), monocytes and macrophages, mast cells, neutrophils and wall components, such as endothelial cells (ECs) and vascular smooth muscle cells (VSMCs). In this regard, molecular pathways related to cytokines, chemokines, growth factors, vasoactive molecules and reactive oxygen species may contribute to the inflammatory process underlying GCA. Altogether, innate cellular and molecular pathways may clarify many pathogenetic aspects of the disease, paving the way for the identification of new biomarkers and for the development of new treatment targets for GCA. This review aims to deeply dissect past and new evidence on the innate immunological disruption behind GCA providing a comprehensive description of disease development from the innate perspective.

Case Report: Good cardiac tolerance to Toripalimab in a CVD patient with oral melanoma

Primary oral melanoma is extremely rare, and the prognosis is very poor. With the development of immunotherapy, melanoma’s treatment landscape changed dramatically. Toripalimab, a recombinant programmed death receptor 1 (PD-1) monoclonal antibody, has been approved as second-line therapy for metastatic melanoma. However, the cardiac toxicity of Toripalimab is seldom reported. This article describes the application of Toripalimab on a patient who suffered from primary oral melanoma accompanied with arrhythmic mitral valve prolapse (AMVP).

Case Summary: A 55-year-old Chinese female was diagnosed with BRAF wild-type oral malignant melanoma by excisional biopsy and genetic test. The melanoma quickly progressed after complete tumor resection. Combined therapy after surgical resection was applied to control the progression of melanoma. Due to this patient’s basic cardiovascular situation, sacubitril–valsartan, spironolactone, and bisoprolol were used to maintain cardiac function. After five antitumor treatment courses, we re-evaluated the patient systemically from the symptom, physical examination, and auxiliary examination. The result showed that the patient who received Toripalimab combined with chemotherapy and radiotherapy did not present severe side effects on the cardiovascular system. The cardiac function remained well.

Conclusions: This case provided evidence of Toripalimab combined with chemotherapy on melanoma patients with complex cardiovascular diseases. Toripalimab demonstrated a manageable safety profile and durable clinical response. In addition, the standard CHF treatment plays a vital role in the protection of cardiac function. In a cancer patient with complex cardiovascular diseases, standard prophylactic CHF treatment should be applied at an early stage.

Prediction of Immune-Related Adverse Events Induced by Immune Checkpoint Inhibitors With a Panel of Autoantibodies: Protocol of a Multicenter, Prospective, Observational Cohort Study

Introduction: Immune checkpoint inhibitor (ICI) therapy is markedly improving the prognosis of patients with several types of cancer. On the other hand, the growth in the use of these drugs in oncology is associated with an increase in multiple immune-related adverse events (irAEs), whose optimal prevention and management remain unclear. In this context, there is a need for reliable and validated biomarkers to predict the occurrence of irAEs in patients treated with ICIs. Thus, the main objective of this study is to evaluate the diagnostic performance of a sensitive routinely available panel of autoantibodies consisting of antinuclear antibodies, rheumatoid factor, and antineutrophil cytoplasmic antibodies to identify patients at risk of developing irAEs.

Methods and Analysis: A multicenter, prospective, observational, cohort study has been designed to be conducted in patients diagnosed with cancer amenable to ICI therapy. Considering the percentage of ICI-induced irAEs to be 25% and a loss to follow-up of 5%, it has been estimated that a sample size of 294 patients is required to detect an expected sensitivity of the autoantibody panel under study of 0.90 with a confidence interval (95%) of no less than 0.75. For 48 weeks, patients will be monitored through the oncology outpatient clinics of five hospitals in Spain. Immune-related adverse events will be defined and categorized according to CTCAE v. 5.0. All the patients will undergo ordinary blood tests at specific moments predefined per protocol and extraordinary blood tests at the time of any irAE being detected. Ordinary and extraordinary samples will be frozen and stored in the biobank until analysis in the same autoimmunity laboratory when the whole cohort reaches week 48. A predictive model of irAEs will be constructed with potential risk factors of immune-related toxicity including the autoantibody panel under study.

Ethics and Dissemination: This protocol was reviewed and approved by the Ethical Committee of the Basque Country and the Spanish Agency of Medicines and Medical Devices. Informed consent will be obtained from all participants before their enrollment. The authors declare that the results will be submitted to an international peer-reviewed journal for their prompt dissemination.

T-Cell Aging-Associated Phenotypes in Autoimmune Disease

The aging process causes profound restructuring of the host immune system, typically associated with declining host protection against cancer and infection. In the case of T cells, aging leads to the accumulation of a diverse set of T-cell aging-associated phenotypes (TASP), some of which have been implicated in driving tissue inflammation in autoimmune diseases. T cell aging as a risk determinant for autoimmunity is exemplified in two classical autoimmune conditions: rheumatoid arthritis (RA), a disease predominantly affecting postmenopausal women, and giant cell arteritis (GCA), an inflammatory vasculopathy exclusively occurring during the 6th-9th decade of life. Pathogenic T cells in RA emerge as a consequence of premature immune aging. They have shortening and fragility of telomeric DNA ends and instability of mitochondrial DNA. As a result, they produce a distinct profile of metabolites, disproportionally expand their endoplasmic reticulum (ER) membranes and release excess amounts of pro-inflammatory effector cytokines. Characteristically, they are tissue invasive, activate the inflammasome and die a pyroptotic death. Patients with GCA expand pathogenic CD4+ T cells due to aberrant expression of the co-stimulatory receptor NOTCH1 and the failure of the PD-1/PD-L1 immune checkpoint. In addition, GCA patients lose anti-inflammatory Treg cells, promoting tissue-destructive granulomatous vasculitis. In summary, emerging data identify T cell aging as a risk factor for autoimmune disease and directly link TASPs to the breakdown of T cell tolerance and T-cell-induced tissue inflammation.

Large-vessel vasculitis

Large-vessel vasculitis (LVV) manifests as inflammation of the aorta and its major branches and is the most common primary vasculitis in adults. LVV comprises two distinct conditions, giant cell arteritis and Takayasu arteritis, although the phenotypic spectrum of primary LVV is complex. Non-specific symptoms often predominate and so patients with LVV present to a range of health-care providers and settings. Rapid diagnosis, specialist referral and early treatment are key to good patient outcomes. Unfortunately, disease relapse remains common and chronic vascular complications are a source of considerable morbidity. Although accurate monitoring of disease activity is challenging, progress in vascular imaging techniques and the measurement of laboratory biomarkers may facilitate better matching of treatment intensity with disease activity. Further, advances in our understanding of disease pathophysiology have paved the way for novel biologic treatments that target important mediators of disease in both giant cell arteritis and Takayasu arteritis. This work has highlighted the substantial heterogeneity present within LVV and the importance of an individualized therapeutic approach. Future work will focus on understanding the mechanisms of persisting vascular inflammation, which will inform the development of increasingly sophisticated imaging technologies. Together, these will enable better disease prognostication, limit treatment-associated adverse effects, and facilitate targeted development and use of novel therapies.

BMSCs improve TNBS-induced colitis in rats by inducing Treg differentiation by expressing PD-L1

OBJECTIVES

Bone marrow-derived mesenchymal stem cells (BMSCs) show promise in treating inflammatory bowel disease. We tested if BMSCs improve Trinitro-benzene-sulfonic acid (TNBS)-induced colitis by inducing Treg differentiation by modulating programmed cell death 1 ligand 1(PD-L1).

RESULTS

BMSCs were isolated and transfected with PD-L1 siRNA. Sprague-Dawley rats were randomly divided into 4 groups: normal, model, BMSC control, and PD-L1 siRNA BMSC. Colitis was induced by TNBS, except in the normal group. On d4, the BMSC control and PD-L1 siRNA BMSC groups were intravenously injected with BMSCs at a dose of 5 × 10⁶ cells in phosphate-buffered saline (PBS; volume matched). BMSCs were later verified to have reached the colon tissue. BMSC control showed significantly better clinical symptoms and reduced histopathological colitis severity; PD-L1 siRNA BMSC group showed no difference. PD-L1 siRNA reduced: spleen and mesenteric lymph node Tregs, PD-L1, interleukin-10 (IL10), phosphate and tension homology deleted on chromosome ten (PTEN); colon p-Akt and p-mTOR were increased.

CONCLUSIONS

We found that BMSCs can induce Treg differentiation by inhibiting the Akt/mTOR pathway via PD-L1; this significantly improved symptoms and pathology in our ulcerative colitis rat models.

Immune Checkpoint Inhibitor Therapy Induces Inflammatory Activity in the Large Arteries of Lymphoma Patients under 50 Years of Age

Background: Immune checkpoint inhibitors (ICI) have transformed the management of various cancers. Serious and potentially fatal cardiovascular toxicity, as well as a progression of atherosclerosis, have been described, mainly in elderly and comorbid patients. Methods: We investigated 117 arterial segments of 12 young (under 50 years of age), otherwise healthy lymphoma patients pre/post-ICI treatment using 2-[18F]fluorodeoxyglucose (FDG) positron emission tomography (PET). Maximum FDG standardized uptake values (SUVmax) and target-to-background ratios (TBRs) were calculated along arterial segments. Additionally, metabolic activities (SUVmax) of the bone marrow, spleen, and liver were analyzed. The levels of high-sensitivity C-reactive protein (hsCRP) were assessed. Results: ICI therapy induced arterial inflammatory activity, detected by increased TBR in arterial segments without pre-existing inflammation (TBRneg_pre = 1.20 ± 0.22 vs. TBRneg_post = 1.71 ± 0.45, p < 0.001), whereas already-inflamed lesions remained unchanged. Dormant calcified segments (Hounsfield Units-HU ≥ 130) showed a significant increase in TBR values after ICI treatment (TBRcalc_pre = 1.36 ± 0.38 vs. TBRcalc_post = 1.76 ± 0.42, p < 0.001). FDG uptake measured in other organs and hsCRP levels remained unchanged after ICI therapy. Conclusions: Although the effects of ICI therapy on arterial inflammation are still incompletely understood, cancer immunotherapy might be a critical moderator of atherosclerosis with a subsequently increased risk of future cerebro- and/or cardiovascular events in young oncological patients.

A brief report on incidence, radiographic feature and prognostic significance of brain MRI changes after anti-PD-1/PD-L1 therapy in advanced non-small cell lung cancer

INTRODUCTION

Neurologic immune-related adverse events (nirAEs) are uncommon but potentially lethal complications of immune checkpoint inhibitor (ICI) treatment. However, the incidence, radiographic features and prognostic significance of brain magnetic resonance imaging (MRI) changes after ICI treatment remain largely unknown.

METHODS

Consecutive patients with advanced non-small cell lung cancer (NSCLC) at three participating institutions receiving anti-PD-1/PD-L1 therapy from June 2017 to September 2020 were screened, and those who received brain MRI within 6 weeks before ICI initiation and at least one follow-up brain MRI after ICI treatment were included. Serial brain MRI images were independently reviewed by two experienced radiologists.

RESULTS

With a median follow-up of 13.2 months, 27 (20.0%) of the 135 enrolled patients developed certain kind of brain MRI aberration. The 1-, 2- and 3-year cumulative incidence of brain MRI aberration was 17.1%, 36.3% and 52.2%, respectively. Brain MRI aberration indicative of stroke, mimicking typical white matter lesions and presenting as T2-hyperintensity suggestive of CNS vasculitis or encephalitis, was documented in 11, 9 and 4 patients, respectively. Patients with brain MRI aberration had higher clinical benefit rate (p = 0.030), longer progression-free survival (p = 0.015) and a tendency of improved overall survival (p = 0.054).

CONCLUSIONS

Brain MRI aberrations developed after ICI treatment are not uncommon, and their manifestations vary a lot. Patients developing brain MRI aberrations tended to have better prognosis, which needed to be further investigated.

Cellular signaling pathways of T cells in giant cell arteritis

Giant cell arteritis (GCA) is a commonly occurring large vacuities characterized by angiopathy of medium and large-sized vessels. GCA granulomatous formation plays an important role in the pathogenesis of GCA. Analysis of T cell lineages and signaling pathways in GCA have revealed the essential role of T cells in the pathology of GCA. T cells are the dominant population present in GCA lesions. CD4+ T cell subtypes that are present include Th1, Th2, Th9, Th17, follicular helper T (Tfh) cells, and regulatory T (Treg) cells. CD8 T cells can primarily differentiate into cytotoxic CD8+ T lymphocytes and Treg cells. The instrumental part of GCA is the interplay between dendritic cells, macrophages and endothelial cells, which can result in the vascular injury and the characteristics granulomatous infiltrates formation. During the inflammatory loop of GCA, several signaling pathways have been reported to play an essential role in recruiting, activating and differentiating T cells, including T-cell receptor (TCR) signaling, vascular endothelial growth factor (VEGF)-Jagged-Notch signaling and the Janus kinase and signal transducer and activator of transcription (STAT) pathway (JAK-STAT) pathway. In this review, we have focused on the role of T cells and their potential signaling mechanism (s) that are involved in the pathogenesis of GCA. A better understanding of the role of T cells mediated complicated orchestration during the homeostasis and the changes could possibly favor developments of novel treatment strategies against immunological disorders associated with GCA.

Effect of Si-Miao-Yong-An decoction on the differentiation of monocytes, macrophages, and regulatory T cells in ApoE-/- mice

ETHNOPHARMACOLOGICAL RELEVANCE

Si-Miao-Yong-An decoction (SMYAD) is a renowned traditional Chinese medicinal formula. SMYAD was originally recorded in the "Shi Shi Mi Lu", which was edited by medical scientist Chen Shi'duo during the Qing Dynasty. SMYAD has been traditionally used to treat thromboangiitis obliterans. At present, it is mainly used in clinical applications and research of cardiovascular diseases.

AIM OF THE STUDY

To explore the effects of SMYAD on the pathological changes of atherosclerosis (AS) and the differentiation of monocytes, macrophages, and regulatory T (Treg) cells in apolipoprotein E knockout (ApoE-/-) mice.

MATERIALS AND METHODS

Eight C57BL/6J mice, which were fed with normal diet for 16 weeks, were used as control group. Forty ApoE-/- mice were randomly divided into model group, atorvastatin group, SMYAD low-dose (SMYAD-LD) group, SMYAD medium-dose (SMYAD-MD) group, and SMYAD high-dose (SMYAD-HD) group. ApoE-/- mice were fed with western diet (WD) for 8 weeks, and the drugs were continuously administered for 8 weeks. The levels of serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were measured by the esterase method. Morphological changes of the aortic sinus in mice were observed by hematoxylin-eosin (HE) staining, the lipid infiltration of the aorta and aortic sinus were observed by oil red O staining, and the spleen index was calculated. The proportion of Ly6Chigh and Ly6Clow monocyte subsets, macrophages, and their M1 phenotype, as well as Treg cells in spleen were measured by flow cytometry. The expressions of cluster of differentiation 36 (CD36), scavenger receptor A1 (SRA1), lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), F4/80, and fork head frame protein 3 (FOXP3) in aortic sinus were assessed by immunohistochemical staining. The serum levels of oxidized low density lipoprotein (ox-LDL), interleukin-1β (IL-1β), IL-18, transforming growth factor-β (TGF-β), and IL-10 were measured by enzyme-linked immunosorbent assays (ELISA).

RESULTS

Compared with the model group, the level of serum TC and LDL-C decreased in the SMYAD group, the pathological changes of aortic sinus decreased, and lipid infiltration of aorta and aortic sinus also decreased. These decreases were accompanied by a significant downregulation of CD36, SRA1, and LOX-1. Furthermore, the proportions of Ly6Chigh pro-inflammatory monocyte subsets, macrophages, and their M1 phenotypes in spleen decreased significantly, while the proportion of Treg cells increased. In addition, while the expression of F4/80 decreased, the expression of FOXP3 increased in the aorta sinus. The levels of serum pro-inflammatory factors IL-1β and IL-18 decreased.

CONCLUSIONS

SMYAD can improve the pathological changes associated with AS and can inhibit lipid deposition in ApoE-/- mice induced by WD diet. The likely mechanism is the inhibition of the differentiation and recruitment of monocytes and macrophages, the promotion of the differentiation and recruitment of Treg cells, as well as the reduction of the secretion of pro-inflammatory factors.

Patterns of Immune Activation in HIV and Non HIV Subjects and Its Relation to Cardiovascular Disease Risk

Introduction

Insight into inflammation patterns is needed to understand the pathophysiology of HIV and related cardiovascular disease (CVD). We assessed patterns of inflammation related to HIV infection and CVD risk assessed with carotid intima media thickness (CIMT).

Methods

A cross-sectional study was performed in Johannesburg, South Africa, including participants with HIV who were virally suppressed on anti-retroviral therapy (ART) as well as HIV-negative participants who were family members or friends to the HIV-positive participants. Information was collected on CVD risk factors and CIMT. Inflammation was measured with the Olink panel ‘inflammation’, allowing to simultaneously assess 92 inflammation markers. Differences in inflammation patterns between HIV-positive and HIV-negative participants were explored using a principal component analysis (PCA) and ANCOVA. The impact of differentiating immune markers, as identified by ANCOVA, on CIMT was assessed using linear regression while adjusting for classic CVD risk factors.

Results

In total, 185 HIV-positive and 104 HIV negative participants, 63% females, median age 40.7 years (IQR 35.4 – 47.7) were included. HIV-positive individuals were older (+6 years, p <0.01) and had a higher CIMT (p <0.01). No clear patterns of inflammation were identified by use of PCA. Following ANCOVA, nine immune markers differed significantly between HIV-positive and HIV-negative participants, including PDL1. PDL1 was independently associated with CIMT, but upon stratification this effect remained for HIV-negative individuals only.

Conclusion

HIV positive patients on stable ART and HIV negative controls had similar immune activation patterns. CVD risk in HIV-positive participants was mediated by inflammation markers included in this study.

Serum anti-AP3D1 antibodies are risk factors for acute ischemic stroke related with atherosclerosis

Atherosclerosis has been considered as the main cause of morbidity, mortality, and disability worldwide. The first screening for antigen markers was conducted using the serological identification of antigens by recombinant cDNA expression cloning, which has identified adaptor-related protein complex 3 subunit delta 1 (AP3D1) as an antigen recognized by serum IgG antibodies of patients with atherosclerosis. Serum antibody levels were examined using the amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA) using a recombinant protein as an antigen. It was determined that the serum antibody levels against AP3D1 were higher in patients with acute ischemic stroke (AIS), transient ischemic attack, diabetes mellitus (DM), cardiovascular disease, chronic kidney disease (CKD), esophageal squamous cell carcinoma (ESCC), and colorectal carcinoma than those in the healthy donors. The area under the curve values of DM, nephrosclerosis type of CKD, and ESCC calculated using receiver operating characteristic curve analysis were higher than those of other diseases. Correlation analysis showed that the anti-AP3D1 antibody levels were highly associated with maximum intima-media thickness, which indicates that this marker reflected the development of atherosclerosis. The results of the Japan Public Health Center-based Prospective Study indicated that this antibody marker is deemed useful as risk factors for AIS.

Rheumatic Immune-Related Adverse Events-A Consequence of Immune Checkpoint Inhibitor Therapy

The advent of immunotherapy has changed the management and therapeutic methods for a variety of malignant tumors in the last decade. Unlike traditional cytotoxic chemotherapy, which works by interfering with cancer cell growth via various pathways and stages of the cell cycle, cancer immunotherapy uses the immune system to reduce malignant cells' ability to escape the immune system and combat cell proliferation. The widespread use of immune checkpoint inhibitors (ICIs) over the past 10 years has presented valuable information on the profiles of toxic adverse effects. The attenuation of T-lymphocyte inhibitory mechanisms by ICIs results in immune system hyperactivation, which, as expected, is associated with various adverse events defined by inflammation. These adverse events, known as immune-related adverse events (ir-AEs), may affect any type of tissue throughout the human body, which includes the digestive tract, endocrine glands, liver and skin, with reports of cardiovascular, pulmonary and rheumatic ir-AEs as well. The adverse events that arise from ICI therapy are both novel and unique compared to those of the conventional treatment options. Thus, they require a multidisciplinary approach and continuous updates on the diagnostic approach and management.

CMTM6-Deficient Monocytes in ANCA-Associated Vasculitis Fail to Present the Immune Checkpoint PD-L1

Objectives

ANCA-associated vasculitides (AAV) affect small- and medium-sized blood vessels. In active disease, vessel wall infiltrates are mainly composed of monocytes and macrophages. Immune checkpoint molecules are crucial for the maintenance of self-tolerance and the prevention of autoimmune diseases. After checkpoint inhibitor therapy, the development of autoimmune vasculitis has been observed. However, defects of immune checkpoint molecules in AAV patients have not been identified yet.

Methods

Monocytes and monocyte-derived macrophages from AAV patients and healthy age-matched controls were tested for surface expression of immunoinhibitory checkpoint programmed cell death ligand-1 (PD-L1). Using in vitro co-culture approaches, the effect of monocyte PD-L1 expression on CD4⁺ T cell activation and proliferation was tested.

Results

Monocytes from AAV patients displayed lower PD-L1 expression and a defective PD-L1 presentation upon activation, an effect that was correlated with disease activity. Lower PD-L1 expression was due to increased lysosomal degradation of PD-L1 in AAV monocytes. We identified a reduced expression of CMTM6, a protein protecting PD-L1 from lysosomal breakdown, as the underlying molecular defect. PD-L1^low AAV monocytes showed increased stimulatory capacity and induced T cell activation and proliferation. Inhibiting lysosomal function corrected this phenotype by increasing PD-L1, thus normalizing the pro-stimulatory behavior of AAV monocytes.

Conclusions

This study identifies a defect of the immunoinhibitory checkpoint PD-L1 in monocytes from patients with AAV. Low expression of CMTM6 results in enhanced lysosomal degradation of PD-L1, thus providing insufficient negative signaling to T cells. Correcting this defect by targeting lysosomal function may represent a novel strategy to treat AAV.

Innate and Adaptive Immunity in Giant Cell Arteritis

Autoimmune diseases can afflict every organ system, including blood vessels that are critically important for host survival. The most frequent autoimmune vasculitis is giant cell arteritis (GCA), which causes aggressive wall inflammation in medium and large arteries and results in vaso-occlusive wall remodeling. GCA shares with other autoimmune diseases that it occurs in genetically predisposed individuals, that females are at higher risk, and that environmental triggers are suspected to beget the loss of immunological tolerance. GCA has features that distinguish it from other autoimmune diseases and predict the need for tailored diagnostic and therapeutic approaches. At the core of GCA pathology are CD4⁺ T cells that gain access to the protected tissue niche of the vessel wall, differentiate into cytokine producers, attain tissue residency, and enforce macrophages differentiation into tissue-destructive effector cells. Several signaling pathways have been implicated in initiating and sustaining pathogenic CD4⁺ T cell function, including the NOTCH1-Jagged1 pathway, the CD28 co-stimulatory pathway, the PD-1/PD-L1 co-inhibitory pathway, and the JAK/STAT signaling pathway. Inadequacy of mechanisms that normally dampen immune responses, such as defective expression of the PD-L1 ligand and malfunction of immunosuppressive CD8⁺ T regulatory cells are a common theme in GCA immunopathology. Recent studies are providing a string of novel mechanisms that will permit more precise pathogenic modeling and therapeutic targeting in GCA and will fundamentally inform how abnormal immune responses in blood vessels lead to disease.

Comprehensive Analysis of the Immune Infiltrates and Aberrant Pathways Activation in Atherosclerotic Plaque

Atherosclerosis is the pathological basis of many cardiovascular and cerebrovascular diseases. The development of gene chip and high-throughput sequencing technologies revealed that the immune microenvironment of coronary artery disease (CAD) in high-risk populations played an important role in the formation and development of atherosclerotic plaques. Three gene expression datasets related to CAD were assessed using high-throughput profiling. CIBERSORT analysis revealed significant differences in five types of immune cells: activated dendritic cells (DCs), T follicular helper cells (Tfhs), resting CD4+ T cells, regulatory T cells (Tregs), and γδ T cells. Immune transcriptome analysis indicated higher levels of inflammatory markers (cytolytic activity, antigen presentation, chemokines, and cytokines) in the cases than in the controls. The level of activated DCs and the lipid clearance signaling score were negatively correlated. We observed a positive correlation between the fraction of Tfhs and lipid biosynthesis. Resting CD4+ T cells and the activity of pathways related to ossification in bone remodeling and glutathione synthesis showed a negative correlation. Gamma delta T cells negatively correlated with IL-23 signaling activity. GSEA revealed a close association with the inflammatory immune microenvironment. The present study revealed that CAD patients may have an inflammatory immune microenvironment and provides a timely update on anti-inflammatory therapies under current investigation.

Constructing a ceRNA-immunoregulatory network associated with the development and prognosis of human atherosclerosis through weighted gene co-expression network analysis

There is now overwhelming experimental and clinical evidence that atherosclerosis (AS) is a chronic inflammatory disease. The recent discovery of a new group of mediators known as competing endogenous RNA (ceRNA) offers a unique opportunity for investigating immunoregulation in AS. In this study, we used gene expression profiles from GEO database to construct a lncRNA-miRNA-mRNA ceRNA network during AS plaque development through weighted gene co-expression network analysis (WGCNA). GO annotation and pathway enrichment analysis suggested that the ceRNA network was mainly involved in the immune response. CIBERSORT and GSVA were used to calculate the immune cell infiltration score and identified macrophage as hub immunocyte in plaque development. A macrophage related ceRNA subnetwork was constructed through correlation analysis. Samples from Biobank of Karolinska Endarterectomy (BiKE) were used to identify prognostic factors from the subnetwork and yielded 7 hub factors that can predict ischemic events including macrophage GSVA score and expression value of AL138756.1, CTSB, MAFB, LYN, GRK3, and BID. A nomogram based on the key factors was established. GSEA identified that the PD1 signaling pathway was negatively associated with these prognostic factors which may explain the cardiovascular side effect of immune checkpoint therapy in anti-tumor treatment.

Delicate Role of PD-L1/PD-1 Axis in Blood Vessel Inflammatory Diseases: Current Insight and Future Significance

Immune checkpoint molecules are the antigen-independent generator of secondary signals that aid in maintaining the homeostasis of the immune system. The programmed death ligand-1 (PD-L1)/PD-1 axis is one among the most extensively studied immune-inhibitory checkpoint molecules, which delivers a negative signal for T cell activation by binding to the PD-1 receptor. The general attributes of PD-L1's immune-suppressive qualities and novel mechanisms on the barrier functions of vascular endothelium to regulate blood vessel-related inflammatory diseases are concisely reviewed. Though targeting the PD-1/PD-L1 axis has received immense recognition-the Nobel Prize in clinical oncology was awarded in the year 2018 for this discovery-the use of therapeutic modulating strategies for the PD-L1/PD-1 pathway in chronic inflammatory blood vessel diseases is still limited to experimental models. However, studies using clinical specimens that support the role of PD-1 and PD-L1 in patients with underlying atherosclerosis are also detailed. Of note, delicate balances in the expression levels of PD-L1 that are needed to preserve T cell immunity and to curtail acute as well as chronic infections in underlying blood vessel diseases are discussed. A significant link exists between altered lipid and glucose metabolism in different cells and the expression of PD-1/PD-L1 molecules, and its possible implications on vascular inflammation are justified. This review summarizes the most recent insights concerning the role of the PD-L1/PD-1 axis in vascular inflammation and, in addition, provides an overview exploring the novel therapeutic approaches and challenges of manipulating these immune checkpoint proteins, PD-1 and PD-L1, for suppressing blood vessel inflammation.

Dendritic Cells and T Cells, Partners in Atherogenesis and the Translating Road Ahead

Atherosclerosis is a chronic process associated with arterial inflammation, the accumulation of lipids, plaque formation in vessel walls, and thrombosis with late mortal complications such as myocardial infarction and ischemic stroke. Immune and inflammatory responses have significant effects on every phase of atherosclerosis. Increasing evidence has shown that both innate and adaptive “arms” of the immune system play important roles in regulating the progression of atherosclerosis. Accumulating evidence suggests that a unique type of innate immune cell, termed dendritic cells (DCs), play an important role as central instigators, whereas adaptive immune cells, called T lymphocytes, are crucial as active executors of the DC immunity in atherogenesis. These two important immune cell types work in pairs to establish pro-atherogenic or atheroprotective immune responses in vascular tissues. Therefore, understanding the role of DCs and T cells in atherosclerosis is extremely important. Here, in this review, we will present a complete overview, based on existing knowledge of these two cell types in the atherosclerotic microenvironment, and discuss some of the novel means of targeting DCs and T cells as therapeutic tactics for the treatment of atherosclerosis.

New disappearance of complicated atheromatous plaques on rechallenge with PD-1/PD-L1 axis blockade in non-small cell lung cancer patient: follow up of an unexpected event

Atherosclerosis is considered an irreversible process, with crucial contribution of inflammation and immune cells. Impact of cancer immunotherapy on a partly immune-driven disease, such as atherosclerosis, is poorly understood, but preclinical models suggest its worsening on programmed death/ligand-1 (PD-1/PD-L1) inhibitors. In a previously reported cohort of 11 patients with non-small cell lung cancer (NSCLC) treated with nivolumab and pre-existing complicated atheromatous plaques, 3 patients had a dramatic radiologic reduction of aortic plaques while on nivolumab; of these 3, 2 died receiving no further treatment. The remaining patient was an 83-year-old woman with history of arterial hypertension and hypothyroidism who was diagnosed with locally advanced squamous NSCLC. At relapse, complicated aortic atheromatous plaques were demonstrated on scans. The patient was then treated with nivolumab obtaining stable disease at radiological assessment, which also demonstrated almost complete vanishing of aortic plaques. After relapse and interval treatment with chemotherapy, she experienced new development of aortic atheromatous plaques. At further relapse she received atezolizumab, which yielded disease response and new reduction in aortic plaques, until nearly complete resolution. The observation of a repeated improvement of atheromatous plaques on treatment with PD-1/PD-L1 inhibitors favors the protective role of T cells on atheromatous plaques that is impaired by PD-L1 expression by plaque-associated macrophages. Validation by independent and prospective observation is needed.

Polymyalgia rheumatica with normal inflammatory indices at the time of diagnosis: can we just move a step forward?

The existence of polymyalgia rheumatica (PMR) with normal inflammatory indices at the time of diagnosis still represents a diagnostic conundrum. According to the literature, some patients with PMR following immune checkpoint inhibitory therapy had normal values of both erythrocyte sedimentation rate and C-reactive protein concentrations at the time of diagnosis.

In this short communication we investigated the possibility that in some patients with PMR the main pathogenic mechanism is constituted by inhibition of some checkpoints, such as programmed death receptor-1, programmed death ligand 1, and “cytotoxic” lymphocyte antigen 4. In these patients, the pathogenetic mechanisms underlying PMR can act much more upstream than commonly suggested. Also, we addressed the question of whether these patients should be considered as affected by PMR-like syndromes or by PMR subset.

PD-L1 upregulation by IFN-α/γ-mediated Stat1 suppresses anti-HBV T cell response

Programmed death ligand 1 (PD-L1) has been recently shown to be a major obstacle to antiviral immunity by binding to its receptor programmed death 1 (PD-1) on specific IFN-γ producing T cells in chronic hepatitis B. Currently, IFN-α is widely used to treat hepatitis B virus (HBV) infection, but its antiviral effect vary greatly and the mechanism is not totally clear. We found that IFN-α/γ induced a marked increase of PD-L1 expression in hepatocytes. Signal and activators of transcription (Stat1) was then identified as a major transcription factor involved in IFN-α/γ-mediated PD-L1 elevation both in vitro and in mice. Blockage of the PD-L1/PD-1 interaction by a specific mAb greatly enhanced HBV-specific T cell activity by the gp96 adjuvanted therapeutic vaccine, and promoted HBV clearance in HBV transgenic mice. Our results demonstrate the IFN-α/γ-Stat1-PD-L1 axis plays an important role in mediating T cell hyporesponsiveness and inactivating liver-infiltrating T cells in the hepatic microenvironment. These data raise further potential interest in enhancing the anti-HBV efficacy of IFN-α and therapeutic vaccines.

Giant Cell Arteritis versus Takayasu Arteritis: An Update

Giant cell arteritis (GCA) and Takayasu Arteritis (TAK) are two systemic granulomatous vasculitides affecting medium- and large-sized arteries. Similarities in GCA and TAK regarding the clinical presentation, the systemic inflammatory response and the distribution of the arterial lesions, have triggered a debate over the last decade about whether GCA and TAK represent two different diseases, or are age-associated different clinical phenotypes of the same disease. On the other hand, there are differences regarding epidemiology, several clinical features (eg, polymyalgia rheumatica in GCA) and treatment. The aim of this review is to present the latest data regarding this question and to shed some light on the differences and similarities between GCA and TAK regarding epidemiology, genetics, pathogenesis, histopathology, clinical presentation, imaging and treatment. The existing data in literature support the opinion that GCA and TAK are different clinical entities.

Rheumatic Manifestations in Patients Treated with Immune Checkpoint Inhibitors

Immune checkpoint inhibitors (ICIs) are monoclonal antibodies that activate the immune system, aiming at enhancing antitumor immunity. Their clinical efficacy is well-documented, but the side effects associated with their use are still under investigation. These drugs cause several immune-related adverse events (ir-AEs), some of which stand within the field of rheumatology. Herein, we present a literature review performed in an effort to evaluate all publicly available clinical data regarding rheumatic manifestations associated with ICIs. The most common musculoskeletal ir-AEs are inflammatory arthritis, polymyalgia rheumatica and myositis. Non-musculoskeletal rheumatic manifestations are less frequent, with the most prominent being sicca, vasculitides and sarcoidosis. Cases of systemic lupus erythematosus or scleroderma are extremely rare. The majority of musculoskeletal ir-AEs are of mild/moderate severity and can be managed with steroids with no need for ICI discontinuation. In severe cases, more intense immunosuppressive therapy and permanent ICI discontinuation may be employed. Oncologists should periodically screen patients receiving ICIs for new-onset inflammatory musculoskeletal complaints and seek a rheumatology consultation in cases of persisting symptoms.

Cardiac adverse events of PD-1 and PD-L1 inhibitors in cancer protocol for a systematic review and network meta-analysis: A protocol for systematic review

INTRODUCTION

Programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) inhibitors have been increasingly used in the treatment of cancer. Immunosuppressive therapy can control the cancer well and is suitable for the moderate to severe diseases. However, according to clinical observation, immune-related cardiac adverse events against PD-1or/and PD-L1 are inevitable, but generally reversible. Understanding the cardiac adverse events of PD-1 or/and PD-L1 inhibitors is crucial to improve the anti-cancer efficacy and ensure the life safety of patients. The variability of cardiac adverse events between different immunosuppressants and different cancers is not clear.

METHODS AND ANALYSIS

This protocol established in this study has been reported following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols. We will search the following electronic bibliographic databases: PubMed, Cochrane Library, EMBASE databases and ClinicalTrials.gov from their inception to December 2019. We will use a combination of Medical Subject Heading, and free-text terms with various synonyms to search based on the Eligibility criteria. We will include RCTs on PD-1 or/and PD-L1 inhibitors therapy to analyze. In addition, our study will include some clinical trials. All relevant RCTs will be included, such as early phase I/II, phase III experimental trials, prospective and retrospective observational studies. According to the inclusion and exclusion criteria outlined above, the full texts of each eligible study will be retrieved for further identification by one reviewer. Two authors will screen the titles and abstracts of all records retrieved in above electronic databases independently to find potentially eligible reviews. Data will be extracted by 2 reviewers independently using a pre-designed data extraction form. The other reviewer will validate data. I-square (I) test, substantial heterogeneity, sensitivity analysis and publication bias assessment will be performed accordingly. For our network meta-analysis, we will use Stata 15.0 and WinBUGS 1.4.3.

ETHICS AND DISSEMINATION

Ethics approval and patient consent would be not required because the data of this network meta-analysis mainly are obtained from existing resources. This network meta-analysis will be published in a peer-reviewed journal.

PROSPERO NUMBER

CRD42019142865.

Humanized Mice as an Effective Evaluation System for Peptide Vaccines and Immune Checkpoint Inhibitors

Peptide vaccination was developed for the prevention and therapy of acute and chronic infectious diseases and cancer. However, vaccine development is challenging, because the patient immune system requires the appropriate human leukocyte antigen (HLA) recognition with the peptide. Moreover, antigens sometimes induce a low response, even if the peptide is presented by antigen-presenting cells and T cells recognize it. This is because the patient immunity is dampened or restricted by environmental factors. Even if the immune system responds appropriately, newly-developed immune checkpoint inhibitors (ICIs), which are used to increase the immune response against cancer, make the immune environment more complex. The ICIs may activate T cells, although the ratio of responsive patients is not high. However, the vaccine may induce some immune adverse effects in the presence of ICIs. Therefore, a system is needed to predict such risks. Humanized mouse systems possessing human immune cells have been developed to examine human immunity in vivo. One of the systems which uses transplanted human peripheral blood mononuclear cells (PBMCs) may become a new diagnosis strategy. Various humanized mouse systems are being developed and will become good tools for the prediction of antibody response and immune adverse effects.

Isolated testicular vasculitis due to immune checkpoint inhibitor

Immune checkpoint inhibitors are increasingly being used to treat various malignancies; consequently, more rheumatological side effects, ranging from arthritis to vasculitis, are being reported. Here we present, for the first time, a case of vasculitis involving the testicle in the setting of an immune checkpoint inhibitor. As reported in previous cases, recurrence of a malignancy, as opposed to vasculitis, was initially suspected, thus creating a diagnostic dilemma. These rheumatological side effects have garnered attention as they potentially provide a window into in the pathogenesis of rheumatological diseases.

Gene and miRNA expression in giant cell arteritis-a concise systematic review of significantly modified studies

Giant cell arteritis (GCA) is a systemic vasculitis in individuals older than 50 years, characterized by headaches, visual disturbances, painful scalp, jaw claudication, impairment of limb arteries, and systemic inflammation, among other symptoms. GCA diagnosis is confirmed by a positive temporal artery biopsy (TAB) or by imaging modalities. A prominent acute phase response with inflammation is the hallmark of the disease, predominantly targeting large- and medium-sized arteries leading to stenosis or occlusion of arterial lumen. To date, there are no reliable tissue markers specific for GCA. Scarce reports have indicated the importance of epigenetics in GCA. The current systematic review reports significantly changed candidate biomarkers in TABs of GCA patients compared to non-GCA patients using qPCR.

Hantavirus-Driven PD-L1/PD-L2 Upregulation: An Imperfect Viral Immune Evasion Mechanism

Viruses often subvert antiviral immune responses by taking advantage of inhibitory immune signaling. We investigated if hantaviruses use this strategy. Hantaviruses cause viral hemorrhagic fever (VHF) which is associated with strong immune activation resulting in vigorous CD8+ T cell responses. Surprisingly, we observed that hantaviruses strongly upregulate PD-L1 and PD-L2, the ligands of checkpoint inhibitor programmed death-1 (PD-1). We detected high amounts of soluble PD-L1 (sPD-L1) and soluble PD-L2 (sPD-L2) in sera from hantavirus-infected patients. In addition, we observed hantavirus-induced PD-L1 upregulation in mice with a humanized immune system. The two major target cells of hantaviruses, endothelial cells and monocyte-derived dendritic cells, strongly increased PD-L1 and PD-L2 surface expression upon hantavirus infection in vitro. As an underlying mechanism, we found increased transcript levels whereas membrane trafficking of PD-L1 was not affected. Further analysis revealed that hantavirus-associated inflammatory signals and hantaviral nucleocapsid (N) protein enhance PD-L1 and PD-L2 expression. Cell numbers were strongly reduced when hantavirus-infected endothelial cells were mixed with T cells in the presence of an exogenous proliferation signal compared to uninfected cells. This is compatible with the concept that virus-induced PD-L1 and PD-L2 upregulation contributes to viral immune escape. Intriguingly, however, we observed hantavirus-induced CD8+ T cell bystander activation despite strongly upregulated PD-L1 and PD-L2. This result indicates that hantavirus-induced CD8+ T cell bystander activation bypasses checkpoint inhibition allowing an early antiviral immune response upon virus infection.

Arterial events in cancer patients-the case of acute coronary thrombosis

Patients with cancer are at high risk for both venous and arterial thrombotic complications. A variety of factors account for the greater thrombotic risk, including the underlying malignancy and numerous cancer-directed therapies. The occurrence of an acute thrombotic event in patients with cancer is associated with substantial morbidity and mortality. Acute coronary syndrome (ACS) represents a particularly important cardiovascular complication in cancer patients. With cardio-vascular risk factors becoming more prevalent in an aging cancer population that is surviving longer, questions pertaining to the appropriate management of vascular toxicity are likely to assume even greater value in the coming years. In this article, we review the current understanding of ACS in patients with cancer. The predisposition to thrombosis in a malignant host and the cancer treatments most commonly associated with vascular toxicity are reviewed. Risk prediction and management strategies are discussed, and discrepancies in the clinical evidence are highlighted.

Review: What Is the Current Evidence for Disease Subsets in Giant Cell Arteritis?

Giant cell arteritis (GCA) is an autoimmune vasculitis affecting large and medium‐sized arteries. Ample evidence indicates that GCA is a heterogeneous disease in terms of symptoms, immune pathology, and response to treatment. In the current review, we discuss the evidence for disease subsets in GCA. We describe clinical and immunologic characteristics that may impact the risk of cranial ischemic symptoms, relapse rates, and long‐term glucocorticoid requirements in patients with GCA. In addition, we discuss both proven and putative immunologic targets for therapy in patients with GCA who have an unfavorable prognosis. Finally, we provide recommendations for further research on disease subsets in GCA.