Disruption of the CCL1-CCR8 axis inhibits vascular Treg recruitment and function and promotes atherosclerosis in mice

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

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

Sensing antibody functions with a novel CCR8-responsive engineered cell

Human chemokine receptor 8 (CCR8) is a promising drug target for immunotherapy of cancer and autoimmune diseases. Monoclonal antibody-based CCR8 targeted treatment shows significant inhibition in tumor growth. The inhibition of CCR8 results in the improvement of antitumor immunity and patient survival rates by regulating tumor-resident regulatory T cells. Recently monoclonal antibody drug development targeting CCR8 has become a research hotspot, which also promotes the advancement of antibody evaluation methods. Therefore, we constructed a novel engineered customized cell line HEK293-cAMP-biosensor-CCR8 combined with CCR8 and a cAMP-biosensor reporter. It can be used for the detection of anti-CCR8 antibody functions like specificity and biological activity, in addition to the detection of antibody-dependent cell-mediated cytotoxicity and antibody-dependent-cellular-phagocytosis. We obtained a new CCR8 mAb 22H9 and successfully verified its biological activities with HEK293-cAMP-biosensor-CCR8. Our reporter cell line has high sensitivity and specificity, and also offers a rapid kinetic detection platform for evaluating anti-CCR8 antibody functions.

Identification of a non-canonical chemokine-receptor pathway suppressing regulatory T cells to drive atherosclerosis

CCL17 is produced by conventional dendritic cells (cDCs), signals through CCR4 on regulatory T cells (Tregs), and drives atherosclerosis by suppressing Treg functions through yet undefined mechanisms. Here we show that cDCs from CCL17-deficient mice display a pro-tolerogenic phenotype and transcriptome that is not phenocopied in mice lacking its cognate receptor CCR4. In the plasma of CCL17-deficient mice, CCL3 was the only decreased cytokine/chemokine. We found that CCL17 signaled through CCR8 as an alternate high-affinity receptor, which induced CCL3 expression and suppressed Treg functions in the absence of CCR4. Genetic ablation of CCL3 and CCR8 in CD4+ T cells reduced CCL3 secretion, boosted FoxP3+ Treg numbers, and limited atherosclerosis. Conversely, CCL3 administration exacerbated atherosclerosis and restrained Treg differentiation. In symptomatic versus asymptomatic human carotid atheroma, CCL3 expression was increased, while FoxP3 expression was reduced. Together, we identified a non-canonical chemokine pathway whereby CCL17 interacts with CCR8 to yield a CCL3-dependent suppression of atheroprotective Tregs.

ILC2-mediated immune crosstalk in chronic (vascular) inflammation

Crosstalk between innate and adaptive immunity is pivotal for an efficient immune response and to maintain immune homeostasis under steady state conditions. As part of the innate immune system, type 2 innate lymphoid cells (ILC2s) have emerged as new important regulators of tissue homeostasis and repair by fine-tuning innate-adaptive immune cell crosstalk. ILC2s mediate either pro- or anti-inflammatory immune responses in a context dependent manner. Inflammation has proven to be a key driver of atherosclerosis, resembling the key underlying pathophysiology of cardiovascular disease (CVD). Notably, numerous studies point towards an atheroprotective role of ILC2s e.g., by mediating secretion of type-II cytokines (IL-5, IL-13, IL-9). Boosting these protective responses may be suitable for promising future therapy, although these protective cues are currently incompletely understood. Additionally, little is known about the mechanisms by which chemokine/chemokine receptor signaling shapes ILC2 functions in vascular inflammation and atherosclerosis. Hence, this review will focus on the latest findings regarding the protective and chemokine/chemokine receptor guided interplay between ILC2s and other immune cells like T and B cells, dendritic cells and macrophages in atherosclerosis. Further, we will elaborate on potential therapeutic implications which result or could be distilled from the dialogue of ILC2s with cells of the immune system in cardiovascular diseases.

Soybean (Glycine max) INFOGEST Colonic Digests Attenuated Inflammatory Responses Based on Protein Profiles of Different Varieties

Soybean compounds have been established to modulate inflammation, but less is known about how whole soybean compositions work together after digestion. The objective was to evaluate and compare the anti-inflammatory responses of different soybean varieties under simulated gastrointestinal digestion, with additional consideration of the glycinin:β-conglycinin ratio (GBR). Soybean colonic digests (SCD) inhibited cyclooxygenase (COX)-2 (25-82%), 5-lipoxidase (LOX) (18-35%), and inducible nitric oxide (iNOS) (8-61%). Varieties 88, GN3, and 93 were the most effective inhibitors. SCD (1 mg/mL) of varieties 81 and GN1 significantly (p < 0.05) reduced nitrite production by 44 and 47%, respectively, compared to lipopolysaccharide (LPS)-stimulated macrophages. SCD effectively reduced pro-inflammatory cytokine interleukin (IL)-6 (50 and 80% for 96 and GN1, respectively). Western blot results showed a decrease in the expression of iNOS, p65, and p50. The GBR was in the range of 0.05-1.57. Higher ratio correlated with higher production of IL-1β (r = 0.44) and tumor necrosis factor-alpha (TNF-α, r = 0.56). Inflammatory microarray results showed a significant decrease in expression of markers granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-6 in cells treated with GN1 SCD compared to LPS. The results suggested that SCD exerted its anti-inflammatory potential through nuclear factor kappa B (NF-κΒ) pathway inhibition by decreasing the levels of NF-κB-dependent cytokines and subunits, and inhibition of pro-inflammatory enzyme activity.

The Role of Cytokines in Cholesterol Accumulation in Cells and Atherosclerosis Progression

Atherosclerosis is the most common cardiovascular disease and is the number one cause of death worldwide. Today, atherosclerosis is a multifactorial chronic inflammatory disease with an autoimmune component, accompanied by the accumulation of cholesterol in the vessel wall and the formation of atherosclerotic plaques, endothelial dysfunction, and chronic inflammation. In the process of accumulation of atherogenic lipids, cells of the immune system, such as monocytes, macrophages, dendritic cells, etc., play an important role, producing and/or activating the production of various cytokines—interferons, interleukins, chemokines. In this review, we have tried to summarize the most important cytokines involved in the processes of atherogenesis.

Tumor-infiltrating regulatory T cells as targets of cancer immunotherapy

Regulatory T cells (Tregs) are abundant in tumor tissues, raising a question of whether immunosuppressive tumor-infiltrating Tregs (TI-Tregs) can be selectively depleted or functionally attenuated to evoke effective anti-tumor immune responses by conventional T cells (Tconvs), without perturbing Treg-dependent immune homeostasis in healthy organs and causing autoimmunity. Here, we review current cancer immunotherapy strategies, including immune checkpoint blockade (ICB) antibodies against CTLA-4 and PD-1 and discuss their effects on TI-Tregs. We also discuss approaches that exploit differentially regulated molecules on the cell surface (e.g., CTLA-4) and intracellularly (e.g., T cell receptor signaling molecules) between TI-Tregs and Tconvs as well as their dependence on cytokines (e.g., IL-2) and metabolites (e.g., lactate). We envisage that targeting TI-Tregs could be effective as a monotherapy and/or when combined with ICB antibodies.

Characteristics and pathogenesis of chemokines in the post-stroke stage

Chemokines, as small molecular proteins, play a crucial role in the immune and inflammatory responses after stroke. A large amount of evidence showed chemokines and their receptors were increasingly recognized as potential targets for stroke treatment, which were involved in the processing of neovascularization, neurogenesis, and neural network reconstruction. In this review, we summarized the characteristics of chemokine alterations throughout the post-stroke nerve repair phase to gain insight into the pathological mechanisms of chemokines and find effective therapeutic targets for stroke.

Monocyte secretory profiling in a clinical and MEFV genotype-characterized cohort of Danish familial Mediterranean fever patients: diagnostic potential of CCL1 and CXCL1

OBJECTIVE

The autoinflammatory disease familial Mediterranean fever (FMF), characterized by recurrent attacks of sterile fever, serosal, and/or synovial inflammation, is caused by variants in the Mediterranean fever gene, MEFV, coding for the pyrin inflammasome sensor. The diagnosis of FMF is mainly based on clinical symptoms and confirmed by detection of disease-associated MEFV variants. However, the diagnosis is challenging among patients carrying variants of uncertain clinical significance (VUS). In this study, we aimed to identify potential FMF discriminatory diagnostic markers in a cohort of clinically characterized FMF patients.

METHOD

We established a cohort of clinically and MEFV genotype-characterized FMF patients by enrolling patients from major Danish hospitals (n = 91). The secretory profile of pyrin inflammasome-activated monocytes from healthy donors (HDs) and MEFV-characterized FMF patients (n = 28) was assessed by analysing cell supernatants for a custom-designed panel of 23 cytokines, chemokines, and soluble tumour necrosis factor receptors associated with monocyte and macrophage function.

RESULTS

MEFV genotypes in Danish FMF patients were associated with age at symptom onset (p < 0.05), FMF among relatives (p < 0.01), proportion of patients in colchicine treatment (p < 0.01), and treatment response (p < 0.05). Secretion of chemokines CCL1 and CXCL1 from pyrin-activated FMF monocytes was significantly decreased compared to HDs (p < 0.05), and could discriminate FMF patients with 'non-confirmatory' MEFV genotypes from HDs with 80.0% and 70.0% sensitivity for CCL1 and CXCL1, respectively (p < 0.05).

CONCLUSION

Our data suggest that a functional diagnostic assay based on CCL1 or CXCL1 levels in pyrin-activated patient monocytes may contribute to FMF diagnosis in patients with VUS.

MMP9-Associated Tumor Stem Cells, CCL1-Silenced Dendritic Cells, and Cytokine-Induced Killer Cells Have a Remarkable Therapeutic Efficacy for Acute Myeloid Leukemia by Activating T Cells

Purpose

Dendritic cells (DC) are specialized antigen-presenting cells, and cytokine-induced killer (CIK) cells have a specific killing activity to a variety of tumors. However, the underlining mechanism and function of DC-CIK cells in acute myeloid leukemia (AML) remain largely elusive.

Methods

Gene expression profiles of leukemia patients were obtained from TCGA, DC cell components were evaluated using the quanTIseq method, and cancer stem cell scores were estimated using machine learning methods. The transcriptomes were obtained in DC-CIK cells from normal and AML patients by high-throughput sequencing. Large differentially expressed mRNAs were verified by RT-qPCR assay, and MMP9 and CCL1 were selected for subsequent studies in vivo and in vitro experiments.

Results

Significant positive correlations were found with DC versus cancer stem cells (p = 0.008) and the expression of MMP9 versus cancer stem cells (p = 0.018). MMP9 and CCL1 were found to be highly expressed in DC-CIK cells from AML patients. DC-CIK cells with MMP9 and CCL1 knockout alone had little effect on leukemia cells, while knockdown of MMP9 and CCL1 in DC-CIK cells increased cytotoxicity, suppressed proliferation, and induced apoptosis of leukemia cells. In addition, we proved that MMP9- and CCL1-silenced DC-CIK cells significantly elevated the CD³⁺CD⁴⁺ and CD³⁺CD⁸⁺ cells and lowered the CD4⁺PD-1⁺ and CD8⁺PD-1⁺ T cells. Meanwhile, blockage of MMP9 and CCL1 in DC-CIK cells dramatically increased IL-2 and IFN-γ, increased CD107aþ (LAMP-1) and granzyme B (GZMB), and downregulated PD-1, CTLA4, TIM3, and LAG3 T cells from AML patients and AML model mice. Furthermore, activated T cells in DC-CIK cells knocking down MMP9 and CCL1 also prevented proliferation and accelerated apoptosis of AML cells.

Conclusion

Our findings demonstrated that blockage of MMP9 and CCL1 in DC-CIK cells could markedly enhance the therapeutic efficiency in AML via activating T cells.

Interleukin-38 in atherosclerosis

Chronic inflammation caused by immune cells and their mediators is a characteristic of atherosclerosis. Interleukin-38 (IL-38), a member of the IL-1 family, exerts multiple anti-inflammatory effects via specific ligand-receptor interactions. Upon recognizing a specific receptor, IL-38 restrains mitogen-activated protein kinase (MAPK), nuclear factor kappa B (NK-κB), or other inflammation-related signaling pathways in inflammatory disease. Further research has shown that IL-38 also displays anti-atherosclerotic effects and reduces the occurrence and risk of cardiovascular events. On the one hand, IL-38 can regulate innate and adaptive immunity to inhibit inflammation, reduce pathological neovascularization, and inhibit apoptosis. On the other hand, it can curb obesity, reduce hyperlipidemia, and restrain insulin resistance to reduce cardiovascular disease risk. Therefore, this article expounds on the vital function of IL-38 in the development of atherosclerosis to provide a theoretical basis for further in-depth studies of IL-38 and insights on the prophylaxis and treatment of atherosclerosis.

Research progress on Th17 and T regulatory cells and their cytokines in regulating atherosclerosis

Background

Coronary heart disease due to atherosclerosis is the leading cause of death worldwide. Atherosclerosis is considered a chronic inflammatory state in the arterial wall that promotes disease progression and outcome, and immune cells play an important role in the inflammatory process.

Purpose

We review the mechanisms of CD4+ T subsets, i.e., helper T17 (Th17) cells and regulatory T cells (Tregs), in regulating atherosclerosis, focusing on the role of interleukin (IL)-17, IL-10, and other cytokines in this disease and the factors influencing the effects of these cytokines.

Results

IL-17 secreted by Th17 cells can promote atherosclerosis, but few studies have reported that IL-17 can also stabilize atherosclerotic plaques. Tregs play a protective role in atherosclerosis, and Th17/Treg imbalance also plays an important role in atherosclerosis.

Conclusion

The immune response is important in regulating atherosclerosis, and studying the mechanism of action of each immune cell on atherosclerosis presents directions for the treatment of atherosclerosis. Nevertheless, the current studies are insufficient for elucidating the mechanism of action, and further in-depth studies are needed to provide a theoretical basis for clinical drug development.

The Effects of Hypoxic Preconditioned Murine Mesenchymal Stem Cells on Post-Infarct Arrhythmias in the Mouse Model

Ventricular arrhythmias associated with myocardial infarction (MI) have a significant impact on mortality in patients following heart attack. Therefore, targeted reduction of arrhythmia represents a therapeutic approach for the prevention and treatment of severe events after infarction. Recent research transplanting mesenchymal stem cells (MSC) showed their potential in MI therapy. Our study aimed to investigate the effects of MSC injection on post-infarction arrhythmia. We used our murine double infarction model, which we previously established, to more closely mimic the clinical situation and intramyocardially injected hypoxic pre-conditioned murine MSC to the infarction border. Thereafter, various types of arrhythmias were recorded and analyzed. We observed a homogenous distribution of all types of arrhythmias after the first infarction, without any significant differences between the groups. Yet, MSC therapy after double infarction led to a highly significant reduction in simple and complex arrhythmias. Moreover, RNA-sequencing of samples from stem cell treated mice after re-infarction demonstrated a significant decline in most arrhythmias with reduced inflammatory pathways. Additionally, following stem-cell therapy we found numerous highly expressed genes to be either linked to lowering the risk of heart failure, cardiomyopathy or sudden cardiac death. Moreover, genes known to be associated with arrhythmogenesis and key mutations underlying arrhythmias were downregulated. In summary, our stem-cell therapy led to a reduction in cardiac arrhythmias after MI and showed a downregulation of already established inflammatory pathways. Furthermore, our study reveals gene regulation pathways that have a potentially direct influence on arrhythmogenesis after myocardial infarction.

A Novel Panel of Plasma Proteins Predicts Progression in Prodromal Alzheimer's Disease

BACKGROUND

A cheap and minimum-invasive method for early identification of Alzheimer's disease (AD) pathogenesis is key to disease management and the success of emerging treatments targeting the prodromal phases of the disease.

OBJECTIVE

To develop a machine learning-based blood panel to predict the progression from mild cognitive impairment (MCI) to dementia due to AD within a four-year time-to-conversion horizon.

METHODS

We created over one billion models to predict the probability of conversion from MCI to dementia due to AD and chose the best-performing one. We used Alzheimer's Disease Neuroimaging Initiative (ADNI) data of 379 MCI individuals in the baseline visit, from which 176 converted to AD dementia.

RESULTS

We developed a machine learning-based panel composed of 12 plasma proteins (ApoB, Calcitonin, C-peptide, CRP, IGFBP-2, Interleukin-3, Interleukin-8, PARC, Serotransferrin, THP, TLSP 1-309, and TN-C), and which yielded an AUC of 0.91, accuracy of 0.91, sensitivity of 0.84, and specificity of 0.98 for predicting the risk of MCI patients converting to dementia due to AD in a horizon of up to four years.

CONCLUSION

The proposed machine learning model was able to accurately predict the risk of MCI patients converting to dementia due to AD in a horizon of up to four years, suggesting that this model could be used as a minimum-invasive tool for clinical decision support. Further studies are needed to better clarify the possible pathophysiological links with the reported proteins.

Heterogeneity of ILC2s in the Intestine; Homeostasis and Pathology

Group 2 innate lymphoid cells (ILC2s) were identified in 2010 as a novel lymphocyte subset lacking antigen receptors, such as T-cell or B-cell receptors. ILC2s induce local immune responses characterized by producing type 2 cytokines and play essential roles for maintaining tissue homeostasis. ILC2s are distributed across various organs, including the intestine where immune cells are continuously exposed to external antigens. Followed by luminal antigen stimulation, intestinal epithelial cells produce alarmins, such as IL-25, IL-33, and thymic stromal lymphopoietin, and activate ILC2s to expand and produce cytokines. In the context of parasite infection, the tuft cell lining in the epithelium has been revealed as a dominant source of intestinal IL-25 and possesses the capability to regulate ILC2 homeostasis. Neuronal systems also regulate ILC2s through neuropeptides and neurotransmitters, and interact with ILC2s bidirectionally, a process termed “neuro-immune crosstalk”. Activated ILC2s produce type 2 cytokines, which contribute to epithelial barrier function, clearance of luminal antigens and tissue repair, while ILC2s are also involved in chronic inflammation and tissue fibrosis. Recent studies have shed light on the contribution of ILC2s to inflammatory bowel diseases, mainly comprising ulcerative colitis and Crohn’s disease, as defined by chronic immune activation and inflammation. Modern single-cell analysis techniques provide a tissue-specific picture of ILC2s and their roles in regulating homeostasis in each organ. Particularly, single-cell analysis helps our understanding of the uniqueness and commonness of ILC2s across tissues and opens the novel research area of ILC2 heterogeneity. ILC2s are classified into different phenotypes depending on tissue and phase of inflammation, mainly inflammatory and natural ILC2 cells. ILC2s can also switch phenotype to ILC1- or ILC3-like subsets. Hence, recent studies have revealed the heterogeneity and plasticity of ILC2, which indicate dynamicity of inflammation and the immune system. In this review, we describe the regulatory mechanisms, function, and pathological roles of ILC2s in the intestine.

IL-38 in modulating hyperlipidemia and its related cardiovascular diseases

Hyperlipidemia is confirmed to be associated with several health problems that include the combination of diabetes mellitus, obesity, and hypertension, ie, metabolic syndrome. Although the lipid-lowering therapy is an effective treatment in hyperlipidemia and its related cardiovascular diseases (CVDs), the persistence of high atherosclerotic risk is notable which could not be simply explained as a phenomenon of hyperlipidemia. Concerning on this notion, it is imperative to identify novel biomarkers which could monitor treatment and predict adverse cardiovascular events. It is demonstrated that the chronic inflammatory response caused by immune cells is a characteristic of hyperlipidemia and atherosclerosis. Notably, among several inflammatory related cytokines, interleukin 38 (IL-38), as a member of the IL-1 family, plays an important role in anti-inflammatory response by binding with its receptor which inhibits the downstream signaling pathways. In addition, IL-38 suppresses the expression of inflammatory factors mainly through the mitogen-activated protein kinase (MAPK). At the cellular level, IL-38 could inhibit the CD4 positive T lymphocyte into T-helper 17 (Th-17) lymphocyte which further enhances the immunosuppressive activity of the T-regulatory lymphocyte (T-reg) to inhibit the inflammatory response. Consistently, IL-38 is shown to be strongly correlated to development of hyperlipidemic related CVDs. In this review, the roles of IL-38 in the development of hyperlipidemia are fully summarized. Furthermore, a theoretical basis for further in-depth research of IL-38 for treatment of hyperlipidemia is also provided.

The why and how of adaptive immune responses in ischemic cardiovascular disease

Atherosclerotic cardiovascular disease is a major cause of disability and death worldwide. Most therapeutic approaches target traditional risk factors but ignore the fundamental role of the immune system. This is a huge unmet need. Recent evidence indicates that reducing inflammation may limit cardiovascular events. However, the concomitant increase in the risk of lifethreatening infections is a major drawback. In this context, targeting adaptive immunity could constitute a highly effective and safer approach. In this Review, we address the why and how of the immuno-cardiovascular unit, in health and in atherosclerotic disease. We review and discuss fundamental mechanisms that ensure immune tolerance to cardiovascular tissue, and examine how their disruption promotes disease progression. We identify promising strategies to manipulate the adaptive immune system for patient benefit, including novel biologics and RNA-based vaccination strategies. Finally, we advocate for establishing a molecular classification of atherosclerosis as an important milestone in our quest to radically change the understanding and treatment of atherosclerotic disease.

TGF-β-induced CCR8 promoted macrophage transdifferentiation into myofibroblast-like cells

Background: Idiopathic pulmonary fibrosis (IPF) is an interstitial disease of unknown origin, characterized by tissue fibrosis, for which currently there is no effective treatment. Macrophages, the main immune cells in lung tissue, are involved in the whole process of pulmonary fibrosis. In recent years, intercellular transformation has led to wide spread concern among pulmonary fibrosis researchers. Macrophages with flexible heterogeneity and plasticity participate in different physiological processes in the body. Cell chemokine receptor 8 (CCR8) is expressed in a variety of cells and plays a significant chemotactic role in the induction of cell activation and migration. It can also promote the differentiation of macrophages under certain environmental conditions. The current study is intended to explore the role of CCR8 in macrophage to myofibroblast transdifferentiation (MMT) in IPF. Methods: We conducted experiments using CCR8-specific small interfering RNA (siRNA), an autophagy inhibitor (3-methyladenine, 3-MA), and an agonist (rapamycin) to explore the underlying mechanisms of macrophage transdifferentiation into myofibroblast cells in transforming growth factor-beta (TGF-β)-induced pulmonary fibrosis. Results: TGF-β treatment increased the CCR8 protein level in a time- and dose-dependent manner in mouse alveolar macrophages, as well as macrophage transdifferentiation-related markers, including vimentin, collagen 1, and a-SMA, and cell migration. In addition, the levels of autophagy were enhanced in macrophages treated with TGF-β. We found that 3-MA, an autophagy inhibitor, decreased the expression levels of macrophage transdifferentiation-related markers and attenuated cell migration. Furthermore, the inhibition of CCR8 via CCR8-specific siRNA reduced the levels of autophagy and macrophage transdifferentiation-related markers, and inhibited the cell migration. Enhancing autophagy with rapamycin attenuated the inhibition effect of CCR8-specific siRNA on macrophage migration and the increase in myofibroblast marker proteins. Conclusions: Our findings showed that the macrophages exposed to TGF-β had the potential to transdifferentiate into myofibroblasts and CCR8 was involved in the process. The effect of CCR8 on TGF-β-induced macrophage transdifferentiation occurs mainly through autophagy. Targeting CCR8 may be a novel therapeutic strategy for the treatment of IPF.

PCSK9 Imperceptibly Affects Chemokine Receptor Expression In Vitro and In Vivo

Proprotein convertase subtilin/kexin type 9 (PCSK9) is a protease secreted mainly by hepatocytes and in lesser quantities by intestines, pancreas, and vascular cells. Over the years, this protease has gained importance in the field of cardiovascular biology due to its regulatory action on the low-density lipoprotein receptor (LDLR). However, recently, it has also been shown that PCSK9 acts independent of LDLR to cause vascular inflammation and increase the severity of several cardiovascular disorders. We hypothesized that PCSK9 affects the expression of chemokine receptors, major mediators of inflammation, to influence cardiovascular health. However, using overexpression of PCSK9 in murine models in vivo and PCSK9 stimulation of myeloid and vascular cells in vitro did not reveal influences of PCSK9 on the expression of certain chemokine receptors that are known to be involved in the development and progression of atherosclerosis and vascular inflammation. Hence, we conclude that the inflammatory effects of PCSK9 are not associated with the here investigated chemokine receptors and additional research is required to elucidate which mechanisms mediate PCSK9 effects independent of LDLR.

NAFLD as a continuous driver in the whole spectrum of vascular disease

Vascular disease is the prime determinant to cardiovascular morbidities and mortalities, which comprises the early vascular damage and subsequent cardiovascular events. Non-alcohol Fatty Liver Disease (NAFLD) is a systemic metabolic disorder that drives the progression of vascular disease through complex interactions. Although a causal relationship between NAFLD and cardiovascular disease (CVD) has not been established, a growing number of epidemiological studies have demonstrated an independent association between NAFLD and early vascular disease and subsequent cardiovascular events. In addition, mechanistic studies suggest that NAFLD initiates and accelerates vascular injury by increasing systemic inflammation and oxidative stress, impairing insulin sensitivity and lipid metabolism, and modulating epigenetics, the intestinal flora and hepatic autonomic nervous system; thus, NAFLD is a putative driving force for CVD progression. In this review, we summarize the clinical evidence supporting the association of NAFLD with subclinical vascular disease and cardiovascular events and discuss the potential mechanisms by which NAFLD promotes the progression of vascular disease.

Splenectomy increases blood pressure and abolishes sex differences in renal T-regulatory cells in spontaneously hypertensive rats

Over the past decade there has been increasing support for a role of the immune system in the development of hypertension. Our lab has previously reported that female spontaneously hypertensive rats (SHRs) have a blood pressure (BP)-dependent increase in anti-inflammatory renal regulatory T cells (Tregs), corresponding to lower BP compared with males. However, little is known regarding the mechanism for greater renal Tregs in females. The current study was designed to test the hypothesis that the greater relative abundance of renal Tregs in female SHR is due to greater Treg production. To test this hypothesis, T cell profiles were measured in the spleen by flow cytometry in male and female SHR at 5 and 14 weeks of age. Splenic Tregs did not differ between males and females, suggesting sex differences in renal Tregs is not due to differences in production. To assess the role of the spleen in sex differences in renal Tregs and BP control, rats were randomized to receive sham surgery (CON) or splenectomy (SPLNX) at 12 weeks of age and implanted with telemeters to measure BP. After 2 weeks, kidneys were harvested for flow cytometric analysis of T cells. Splenectomy increased BP in both sexes after 2 weeks. Renal Tregs decreased in both sexes after splenectomy, abolishing the sex differences in renal Tregs. In conclusion, splenic Tregs were comparable in male and female SHRs, suggesting that sex differences in renal Tregs is due to differences in renal Treg recruitment, not Treg production.

Implications for the role of lipopolysaccharide in the development of atherosclerosis

Mounting scientific evidence over decades has established that atherosclerosis is a chronic inflammatory disorder. Among the potentially critical sources of vascular inflammation during atherosclerosis are the components of pathogenic bacteria, especially lipopolysaccharide (LPS). Toll-like receptor (TLR)-4, expressed on different inflammatory cells involved with the recognition of bacterial LPS, has been recognized to have mutations that are prevalent in a number of ethnic groups. Such mutations have been associated with a decreased risk of atherosclerosis. In addition, epidemiological investigations have proposed that LPS confers a risk factor for the development of atherosclerosis. Gram-negative bacteria are the major source of LPS in an individual's serum, which may be generated during subclinical infections. The major cell receptors on inflammatory cells involved in the pathogenesis of atherosclerosis, like macrophages, monocytes, and dendritic cells (DCs), are CD14, MD-2, and LPS binding protein (LBP). These receptors have been blamed for the development of atherosclerosis through dysregulated activation following LPS recognition. Lipoproteins may also play a role in modulating the LPS-induced inflammatory events during atherosclerosis development. In this review article, we attempt to clarify the role of LPS in the initiation and progression of atherosclerotic lesion development.

Innate Lymphoid Cells in Intestinal Homeostasis and Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a heterogeneous state of chronic intestinal inflammation of unknown cause encompassing Crohn’s disease (CD) and ulcerative colitis (UC). IBD has been linked to genetic and environmental factors, microbiota dysbiosis, exacerbated innate and adaptive immunity and epithelial intestinal barrier dysfunction. IBD is classically associated with gut accumulation of proinflammatory Th1 and Th17 cells accompanied by insufficient Treg numbers and Tr1 immune suppression. Inflammatory T cells guide innate cells to perpetuate a constant hypersensitivity to microbial antigens, tissue injury and chronic intestinal inflammation. Recent studies of intestinal mucosal homeostasis and IBD suggest involvement of innate lymphoid cells (ILCs). These lymphoid-origin cells are innate counterparts of T cells but lack the antigen receptors expressed on B and T cells. ILCs play important roles in the first line of antimicrobial defense and contribute to organ development, tissue protection and regeneration, and mucosal homeostasis by maintaining the balance between antipathogen immunity and commensal tolerance. Intestinal homeostasis requires strict regulation of the quantity and activity of local ILC subpopulations. Recent studies demonstrated that changes to ILCs during IBD contribute to disease development. A better understanding of ILC behavior in gastrointestinal homeostasis and inflammation will provide valuable insights into new approaches to IBD treatment. This review summarizes recent research into ILCs in intestinal homeostasis and the latest advances in the understanding of the role of ILCs in IBD, with particular emphasis on the interaction between microbiota and ILC populations and functions.

Development of Anti-Mouse CC Chemokine Receptor 8 Monoclonal Antibodies for Flow Cytometry

CC chemokine receptor 8 (CCR8) belongs to the class A of G protein-coupled receptor. It is highly expressed on Treg and T helper 2 (T_H2) cells recruited to the inflammation site and is implicated in allergy and asthma. Recently, CCR8+Treg cells have been suggested to be a master regulator in the immunosuppressive tumor microenvironment; therefore, developing sensitive monoclonal antibodies (mAbs) for CCR8 has been desired. This study established a specific and sensitive mAb for mouse CCR8 (mCCR8), which is useful for flow cytometry by using the Cell-Based Immunization and Screening (CBIS) method. The established anti-mCCR8 mAb, C₈Mab-2 (rat IgG_2b, kappa), reacted with mCCR8-overexpressed Chinese hamster ovary-K1 (CHO/mCCR8) cells and P388 (mouse lymphoid neoplasma) or J774-1 (mouse macrophage-like) cells, which express endogenous mCCR8 by flow cytometry. C₈Mab-2, which was established by the CBIS method, could be useful for elucidating the mCCR8-related biological response by flow cytometry.

Influence of oncogenic mutations and tumor microenvironment alterations on extranodal invasion in diffuse large B-cell lymphoma

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is an aggressive subtype of lymphoma, and multiple extranodal involvement (ENI) indicates adverse clinical outcomes. The aim of this study was to investigate the influence of oncogenic mutations and tumor microenvironment alterations on ENI in DLBCL.

METHODS

The clinical features of 1960 patients with newly diagnosed DLBCL were analyzed, and DNA and RNA sequencing was performed on 670 and 349 patients, respectively. Oncogenic mutations and tumor microenvironment alterations were compared according to ENI and evaluated in zebrafish patient-derived tumor xenograft models.

RESULTS

Multiple ENI was significantly associated with poor performance status, advanced stage, elevated serum lactate dehydrogenase, low response rate, and inferior prognosis. Lymphoma invasion of the bones, spleen, bone marrow, liver, and central nervous system were independent unfavorable prognostic factors. MYD88 was frequently mutated in patients with multiple ENI, co-occurred with mutations in CD79B, PIM1, TBL1XR1, BTG1, MPEG1, and PRDM1, and correlated with invasion of the bones, kidney/adrenal glands, breasts, testes, skin, and uterus/ovaries. For tumor microenvironment alterations, patients with multiple ENI showed higher regulatory T-cell (Treg)-recruiting activity, but lower extracellular matrix-encoding gene expression, than those without ENI and with single ENI. Elevated Treg-recruiting activity was related to mutations in B2M, SGK1, FOXO1, HIST1H1E, and ARID1A, and correlated with invasion of the bone marrow and thyroid. Additionally, mutations in MYD88, PIM1, TBL1XR1, SGK1, FOXO1, HIST1H1E, and ARID1A were associated with decreased major histocompatibility complex class I expression. Zebrafish models further revealed relationships between MYD88 mutations and invasion of the kidneys and gonads, as well as B2M mutations and invasion of the bone marrow. Increased CXCR4 expression is linked to bone marrow invasion in an organotropic way.

CONCLUSIONS

Our findings thus contribute to an improved understanding of the biological behavior of multiple ENI and provide a clinical rationale for targeting ENI in DLBCL.

Th17/Treg Imbalance and Atherosclerosis

Atherosclerosis is nowadays recognized as a chronic inflammatory disease of large arteries. In recent years, cellular and molecular biology studies on atherosclerosis confirmed that the occurrence and development are related to inflammation and autoimmunity. A variety of immune cells, cytokines, and transcription factors are involved in this process. Current studies found that T helper cell 17, regulatory T cells, and their cytokines play an important role in the development of atherosclerosis and vulnerable plaque rupture. Here, we provide a review of the up-to-date applications of T helper cell 17, regulatory T cells, cytokines, and their balance in the prognosis and therapy of atherosclerosis.

High serum CCL20 is associated with tumor progression in penile cancer

Serum cancer biomarker has been proven to be very valuable in cancer diagnosis, disease monitoring and prognosis assessment, despite there is still a lack of serum biomarker for penile cancer (PC). Our initial analysis on public GEO dataset identified CCL20 as a top C-C motif ligand (CCL) gene enriched in PC. The patients with PC exhibited markedly higher preoperative serum CCL20 level than healthy control. The area under the curve (AUC) was 0.855 with the sensitivity of 72.4%, and specificity of 93.5% to distinguish PC. Preoperative serum CCL20 level was significantly associated with clinicopathological characteristics including T stage (P=0.005), nodal status (P=0.008), and pelvic lymph node metastasis (P=0.007). PC Patients with high serum CCL20 level had shorter disease-free survival compared to those with low level (P<0.001). Cox regression analysis showed that serum CCL20 level could serve as an independent prognostic factor for disease-free survival with a HR of 3.980 (95% CI: 1.209-13.098, P=0.023). Furthermore, CCL20 expression was observed in PC tissues and cell lines. Knockdown of CCL20 expression markedly suppressed malignant phenotypes (cell proliferation, clonogenesis, apoptosis escape, migration and invasion), attenuated STAT3 and AKT signaling and reduced MMP2/9 secretion in PC cell lines. Consistently, CCL20 and its receptor CCR6 exhibited correlated expression pattern in PC tissues. In conclusion, serum CCL20 level might serve as a potential diagnostic and prognostic cancer biomarker for PC. CCL20 might activate multiple downstream oncogenic signaling pathways (STAT3, AKT, MMP2/9) to promote malignant progression of PC, which may warrant further investigation in the future.

The novel target：exosoms derived from M2 macrophage

More and more exosome-based therapeutics are being developed with advances in nanotechnology and precision medicine. Exosome is a kind of tiny vesicles with a bilayer of phospholipids, which can transfer biological macromolecules to recipients to influence the biological process. M2 macrophages are closely related to the occurrence and development of serious diseases such as tumor. In addition to the traditional concept of macrophage functions such as opsonization, secretion of cytokines and other soluble factors, some studies have found that the exosome derived from M2 macrophages can influence the development of disease by carrying microRNA, long noncodingRNA and functional proteins to regulate target gene expression as well as related proteins synthesis recently. Here, we outlined the biogenesis of the exosome and its biological functions in disease. Then we focused on elucidating the effects of the exosome derived from M2 macrophages on several diseases and its mechanisms. Finally, we discussed the appropriateness and inappropriateness in existing potential applications based on exosomes and macrophages.

AHR Signaling Dampens Inflammatory Signature in Neonatal Skin γδ T Cells

Background Aryl hydrocarbon receptor (AHR)-deficient mice do not support the expansion of dendritic epidermal T cells (DETC), a resident immune cell population in the murine epidermis, which immigrates from the fetal thymus to the skin around birth. Material and Methods In order to identify the gene expression changes underlying the DETC disappearance in AHR-deficient mice, we analyzed microarray RNA-profiles of DETC, sorted from the skin of two-week-old AHR-deficient mice and their heterozygous littermates. In vitro studies were done for verification, and IL-10, AHR repressor (AHRR), and c-Kit deficient mice analyzed for DETC frequency. Results We identified 434 annotated differentially expressed genes. Gene set enrichment analysis demonstrated that the expression of genes related to proliferation, ion homeostasis and morphology differed between the two mouse genotypes. Importantly, with 1767 pathways the cluster-group “inflammation” contained the majority of AHR-dependently regulated pathways. The most abundant cluster of differentially expressed genes was “inflammation.” DETC of AHR-deficient mice were inflammatory active and had altered calcium and F-actin levels. Extending the study to the AHRR, an enigmatic modulator of AHR-activity, we found approximately 50% less DETC in AHRR-deficient mice than in wild-type-littermates. Conclusion AHR-signaling in DETC dampens their inflammatory default potential and supports their homeostasis in the skin.

Immunobiology of Atherosclerosis: A Complex Net of Interactions

Cardiovascular disease is the leading cause of mortality worldwide, and atherosclerosis the principal factor underlying cardiovascular events. Atherosclerosis is a chronic inflammatory disease characterized by endothelial dysfunction, intimal lipid deposition, smooth muscle cell proliferation, cell apoptosis and necrosis, and local and systemic inflammation, involving key contributions to from innate and adaptive immunity. The balance between proatherogenic inflammatory and atheroprotective anti-inflammatory responses is modulated by a complex network of interactions among vascular components and immune cells, including monocytes, macrophages, dendritic cells, and T, B, and foam cells; these interactions modulate the further progression and stability of the atherosclerotic lesion. In this review, we take a global perspective on existing knowledge about the pathogenesis of immune responses in the atherosclerotic microenvironment and the interplay between the major innate and adaptive immune factors in atherosclerosis. Studies such as this are the basis for the development of new therapies against atherosclerosis.

Exosomes Derived From M2b Macrophages Attenuate DSS-Induced Colitis

Macrophages are commonly classified as M1 macrophages or M2 macrophages. The M2 macrophages are further sub-categorized into M2a, M2b, M2c, and M2d subtypes. The M2a, M2b, and M2c subtypes play roles in anti-inflammatory activity, tissue remodeling, type 2 T helper cell (Th2) activation, and immunoregulation. Previous studies have shown that macrophage exosomes can affect some disease processes. Exosomes are 30-150-nm lipid bilayer membrane vesicles derived from most living cells, with important biological functions. The role of exosomes in preventing the development of autoimmune diseases, including inflammatory bowel disease (IBD), has evoked increasing interest. Here, we analyze the roles of exosomes derived from M2a, M2b, and M2c macrophage phenotypes in dextran sulfate sodium (DSS)-induced colitis. Exosomes were isolated from the supernatant of different types of macrophages and identified via transmission electron microscopy (TEM), western blotting, and NanoSight. The results showed that M2b macrophage exosomes significantly attenuated the severity of DSS-induced colitis in mice. The number of regulatory T (Treg) cells in the spleens of mice with colitis and levels of IL-4 both increased following treatment with M2b macrophage exosomes. In addition, key cytokines associated with colitis (IL-1β, IL-6, and IL-17A) were significantly suppressed, following treatment with M2b macrophage exosomes. The M2b macrophage exosomes exerted protective effects on DSS-induced colitis, mainly mediated by the CC chemokine 1 (CCL1)/CCR8 axis. These findings provide a novel approach for the treatment of IBD.