The soluble forms of CD28, CD86 and CTLA-4 constitute possible immunological markers in patients with abdominal aortic aneurysm

Assessing the causal relationship between circulating immune cells and abdominal aortic aneurysm by bi-directional Mendelian randomization analysis

Although there is an association between abdominal aortic aneurysm (AAA) and circulating immune cell phenotypes, the exact causal relationship remains unclear. This study aimed to explore the causal relationships between immune cell phenotypes and AAA risk using a bidirectional two-sample Mendelian randomization approach. Data from genome-wide association studies pertaining to 731 immune cell traits and AAA were systematically analyzed. Using strict selection criteria, we identified 339 immune traits that are associated with at least 3 single nucleotide polymorphisms. A comprehensive MR analysis was conducted using several methods including Inverse Variance Weighted, Weighted Median Estimator, MR-Egger regression, Weighted Mode, and Simple Median methods. CD24 on switched memory cells (OR = 0.922, 95% CI 0.914-0.929, P = 2.62e-79) at the median fluorescence intensities level, and SSC-A on HLA-DR + natural killer cells (OR = 0.873, 95% CI 0.861-0.885, P = 8.96e-81) at the morphological parameter level, exhibited the strongest causal associations with AAA. In the reverse analysis, no significant causal effects of AAA on immune traits were found. The study elucidates the causal involvement of multiple circulating immune cell phenotypes in AAA development, signifying their potential as diagnostic markers or therapeutic targets. These identified immune traits may be crucial in modulating AAA-related inflammatory pathways.

sCD163, sCD28, sCD80, and sCTLA-4 as soluble marker candidates for detecting immunosenescence

BACKGROUND

Inflammaging, the characteristics of immunosenescence, characterized by continuous chronic inflammation that could not be resolved. It is not only affect older people but can also occur in young individuals, especially those suffering from chronic inflammatory conditions such as autoimmune disease, malignancy, or chronic infection. This condition led to altered immune function and as consequent immune function is reduced. Detection of immunosenescence has been done by examining the immune risk profile (IRP), which uses flow cytometry. These tests are not always available in health facilities, especially in developing countries and require fresh whole blood samples. Therefore, it is necessary to find biomarkers that can be tested using stored serum to make it easier to refer to the examination. Here we proposed an insight for soluble biomarkers which represented immune cells activities and exhaustion, namely sCD163, sCD28, sCD80, and sCTLA-4. Those markers were reported to be elevated in chronic diseases that caused early aging and easily detected from serum samples using ELISA method, unlike IRP. Therefore, we conclude these soluble markers are beneficial to predict pathological condition of immunosenescence.

AIM

To identify soluble biomarkers that could replace IRP for detecting immunosenescence.

CONCLUSION

Soluble costimulatory molecule suchsCD163, sCD28, sCD80, and sCTLA-4 are potential biomarkers for detecting immunosenescence.

Identification of immune-related signatures and pathogenesis differences between thoracic aortic aneurysm patients with bicuspid versus tricuspid valves via weighted gene co-expression network analysis

BACKGROUND

Thoracic aortic aneurysm (TAA) occurs due to pathological aortal dilation, and both individuals with normal tricuspid aortic valves (TAV) or abnormal bicuspid aortic valves (BAV), the latter being a congenital condition, are at risk. However, some differences are present between TAA/BAV and TAA/TAV with respect to their pathophysiological processes and molecular mechanisms, but their exact nature is still mostly unknown. Therefore, it is necessary to elucidate TAA developmental differences among BAV vs. TAV patients.

METHODS

Publically-available gene expression datasets, aortic tissue derived from TAA/BAV and TAA/TAV individuals, were analyzed by weighted gene co-expression network analysis (WGCNA) to identify gene modules associated with those conditions. Gene Ontology (GO) enrichment analysis was performed on those modules to identify the enriched genes within those modules, which were verified by Gene Set Variation Analysis (GSVA) on a dataset derived from aortic smooth muscle cell gene expression between TAA/TAV and TAV/BAV patients. Immune cell infiltration patterns were then analyzed by CIBERSORT, and a protein-protein interaction (PPI) network was constructed based on WGCNA and enrichment analysis results to identify hub genes, followed by validation via stepwise regression analysis. Three signatures most strongly associated with TAA/TAV were confirmed by receiver operating characteristic (ROC) and decision curve analyses (DCA) between prior-established training and testing gene sets.

RESULTS

WGCNA delineated 2 gene modules being associated with TAA/TAV vs. TAA/BAV; both were enriched for immune-associated genes, such as those relating to immune responses, etc., under enrichment analysis. TAA/TAV and TAA/BAV tissues also had differing infiltrating immune cell proportions, particularly with respect to dendritic, mast and CD4 memory T cells. Identified three signatures, CD86, integrin beta 2 (ITGB2) and alpha M (ITGAM), as yielding the strongest associations with TAA/TAV onset, which was verified by areas under the curve (AUC) at levels approximating 0.8 or above under ROC analysis, indicating their predictive value for TAA/TAV onset. However, we did not examine possible confounding variables, so there are many alternative explanations for this association.

CONCLUSIONS

TAA/TAV pathogenesis was found to be more associated with immune-related gene expression compared to TAA/BAV, and the identification of three strongly-associated genes could facilitate their usage as future biomarkers for diagnosing the likelihood of TAA/TAV onset vs. TAA/BAV, as well as for developing future treatments.

Prediction of risk and overall survival of pancreatic cancer from blood soluble immune checkpoint-related proteins

Background

Immune checkpoint inhibition holds promise as a novel treatment for pancreatic ductal adenocarcinoma (PDAC). The clinical significance of soluble immune checkpoint (ICK) related proteins have not yet fully explored in PDAC.

Methods

We comprehensively profiled 14 soluble ICK-related proteins in plasma in 70 PDAC patients and 70 matched healthy controls. Epidemiological data of all subjects were obtained through structured interviews, and patients' clinical data were retrieved from electronical health records. We evaluated the associations between the biomarkers with the risk of PDAC using unconditional multivariate logistic regression. Consensus clustering (k-means algorithm) with significant biomarkers was performed to identify immune subtypes in PDAC patients. Prediction models for overall survival (OS) in PDAC patients were developed using multivariate Cox proportional hazards regression. Harrell's concordance index (C-index), time-dependent receiver operating characteristic (ROC) curve and calibration curve were utilized to evaluate performance of prediction models. Gene expressions of the identified ICK-related proteins in tumors from TCGA were analyzed to provide insight into underlying mechanisms.

Results

Soluble BTLA, CD28, CD137, GITR and LAG-3 were significantly upregulated in PDAC patients (all q < 0.05), and elevation of each of them was correlated with PDAC increased risk (all p < 0.05). PDAC patients were classified into soluble immune-high and soluble immune-low subtypes, using these 5 biomarkers. Patients in soluble immune-high subtype had significantly poorer OS than those in soluble immune-low subtype (log-rank p = 9.7E-03). The model with clinical variables and soluble immune subtypes had excellent predictive power (C-index = 0.809) for the OS of PDAC patients. Furthermore, the immune subtypes identified with corresponding genes' expression in PDAC tumor samples in TCGA showed an opposite correlation with OS to that of immune subtypes based on blood soluble ICK-related proteins (log-rank p =0.02). The immune-high subtype tumors displayed higher cytolytic activity (CYT) score than immune-low subtype tumors (p < 2E-16).

Conclusion

Five soluble ICK-related proteins were identified to be significantly associated with the risk and prognosis of PDAC. Patients who were classified as soluble immune-low subtype based on these biomarkers had better overall survival than those of the soluble immune-high subtype.

Blood immunological profile of abdominal aortic aneurysm based on autoimmune injury

Abdominal aortic aneurysm (AAA) occupies a large part of aorta aneurysm, and if there's no timely intervention or treatment, the risks of rupture and death would rise sharply. With the depth of research in AAA, more and more evidence showed correlations between AAA and autoimmune injury. Currently, a variety of bioactive peptides and cells have been confirmed to be related with AAA progression. Despite the tremendous progress, more than half researches were sampling from lesion tissues, which would be difficult to obtain. Given that the intrusiveness and convenience, serological test take advantages in initial diagnosis. Here we review blood biomarkers associated with autoimmune injury work in AAA evolution, aiming to make a profile on blood immune substances of AAA and provide a thought for potential clinical practice.

Zanubrutinib ameliorates lipopolysaccharide-induced acute lung injury via regulating macrophage polarization

Acute lung injury (ALI) is a disease characterized by pulmonary diffusion dysfunction and its exacerbation stage is acute respiratory distress syndrome (ARDS), which may develop to multiple organ failure and seriously threatens human health. ALI has high mortality rates and few effective treatments, thus effective protection measures for ALI are becoming increasingly important. Macrophages play a key regulatory role in the pathogenesis of ALI, and the degree of macrophage polarization is closely related to the severity and prognosis of ALI. In this study, we evaluated the effects of Zanubrutinib (ZB), a BTK small molecule inhibitor approved by the FDA for the treatment of cell lymphoma, on macrophage polarization and acute lung injury. In the in vivo study, we constructed a mouse model of Lipopolysaccharide (LPS)-induced acute lung injury and found that ZB could improve the acute injury of mouse lungs by inhibiting the secretion of proinflammatory factors and promoting the secretion of anti-inflammatory factors, reduce the number of inflammatory cells in alveolar lavage fluid, and then alleviate the inflammatory response. In vivo and in vitro studies have shown that ZB could inhibit the M1 macrophage polarization and promote the M2 macrophage polarization. Subsequent mechanistic studies revealed that ZB could inhibit the macrophage M1 polarization via targeting BTK activation and inhibiting JAK2/STAT1 and TLR4/MyD88/NF-κB signaling pathways, and promote the macrophage M2 polarization by promoting the activation of STAT6 and PI3K / Akt signaling pathways. In summary, ZB has shown therapeutic effect in LPS-induced acute lung injury in mice, which provides a potential candidate drug to treat acute lung injury.

Serum Concentration of the Phytohormone Abscisic Acid Is Associated With Immune-Regulatory Mediators and Is a Potential Biomarker of Disease Severity in Chronic Obstructive Pulmonary Disease

COPD and asthma are two distinct but sometimes overlapping diseases exhibiting varying degrees and types of inflammation on different stages of the disease. Although several biomarkers are defined to estimate the inflammatory endotype and stages in these diseases, there is still a need for new markers and potential therapeutic targets. We investigated the levels of a phytohormone, abscisic acid (ABA) and its receptor, LANCL2, in COPD patients and asthmatics. In addition, PPAR-γ that is activated by ABA in a ligand-binding domain-independent manner was also included in the study. In this study, we correlated ABA with COPD-propagating factors to define the possible role of ABA, in terms of immune regulation, inflammation, and disease stages. We collected blood from 101 COPD patients, 52 asthmatics, and 57 controls. Bronchoscopy was performed on five COPD patients and 29 controls. We employed (i) liquid chromatography–tandem mass spectrometry and HPLC to determine the ABA and indoleamine 2,3-dioxygenase levels, respectively; (ii) real-time PCR to quantify the gene expression of LANCL2 and PPAR-γ; (iii) Flow cytometry to quantify adipocytokines; and (iv) immunoturbidimetry and ELISA to measure CRP and cytokines, respectively. Finally, a multinomial regression model was used to predict the probability of using ABA as a biomarker. Blood ABA levels were significantly reduced in COPD patients and asthmatics compared to age- and gender-matched normal controls. However, PPAR-γ was elevated in COPD patients. Intriguingly, ABA was positively correlated with immune-regulatory factors and was negatively correlated with inflammatory markers, in COPD. Of note, ABA was increased in advanced COPD stages. We thereby conclude that ABA might be involved in regulation of COPD pathogenesis and might be regarded as a potential biomarker for COPD stages.

PD-1/PD-L1 pathway activation restores the imbalance of Th1/Th2 and treg/Th17 cells subtypes in immune thrombocytopenic purpura patients

This study aims to investigate the changes of cytokines and the effect of programmed death ligand 1 (PD-L1) signaling pathway on T cell function in patients with immune thrombocytopenic purpura (ITP).Totally, 40 untreated ITP patients were recruited and 30 healthy people were recruited as the healthy control. Then whole blood of ITP patients and healthy control was collected, respectively. The sPD-L1/anti-PD-1 was used to activate or block the programmed death (PD-1)/PD-L1 signaling pathway. The expression of PD-1 and PD-L1 on peripheral blood mononuclear cells (PBMCs) were detected by flow cytometry. PBMCs were treated with cluster of differentiation (CD3), cluster of differentiation 28 (CD28), and phytohaemagglutinin (PHA) for 48 hours. Serum levels of sPD-1, sPD-L1, and cytokines were measured by enzyme-linked immunosorbent assay (ELISA).Compared with the healthy control group, the percentages of PD-1+CD3+CD4+ T cells and PD-L1+HLA-DR+CD11c+ DC cells were increased in ITP patients. The levels of interferon-gamma (IFN-γ), interleukin-17 (IL-17), and sPD-1 in the serum of ITP patients were increased, while IL-4 and transforming growth factor-β (TGF-β) were decreased. Additionally, the level of sPD-1 was negatively correlated with the platelet count. Consistently, after treatment with CD3, CD28, and PHA, IFN-γ and IL-17 levels in culture supernatant of PBMCs from ITP patients were significantly higher than those from healthy controls whereas IL-4 and TGF-β levels were significantly lower. Furthermore, IFN-γ and IL-17 levels secreted by PBMCs from ITP patients decreased after sPD-L1 administration, however, IL-4 and TGF-β levels were increased. The level of IFN-γ in ITP group remained higher after anti-PD-1 blockage, but the levels of IL-4, TGF-β, and IL-17 were not significantly influenced.sPD-1 may cause the dysfunction of PD-1/PD-L1 signaling pathway, and its level is related to the severity of ITP patients. Activation of PD-1/PD-L1 with sPD-L1 may restore the imbalance of Th1/Th2 and Treg/Th17 cell subtypes in ITP patients but anti-PD-1 may exacerbate disease by enhancing IFN-γ production.

PD-L1 Gene Polymorphism and High Level of Plasma Soluble Pd-L1 Protein may be aSsociated with Non-Small Cell Lung Cancer

Background

PD-1 and its ligand PD-L1 belong to the co-inhibition molecules, which can downregulate immune responses. The PD-L1 polymorphism and the level of soluble PD-L1 (sPD-L1) were investigated in non-small cell lung cancer (NSCLC).

Methods

A total of 288 NSCLC patients and 300 controls were enrolled. An A/C polymorphism at position 8923 in the PD-L1 gene was genotyped using the polymerase chain reaction-restriction fragment length polymorphism method.

Results

The prevalence of the 8923C allele was significantly higher in NSCLC patients than controls (10.2% versus 5.3%, p = 0.002, odds ratio 2.03, 95% confidence interval 1.30-3.17; data were adjusted for age and sex). NSCLC patients also showed increased plasma levels of sPD-L1 compared to controls (1.92 ng/mL versus 0.91 ng/mL, p<0.001). Furthermore, lung adenocarcinoma patients had higher sPD-L1 levels than patients with squamous cell carcinoma (p<0.01). However, no association was observed between the different genetic variants and plasma concentrations of sPD-L1.

Conclusions

The PD-L1 8923A/C polymorphism could be associated with increased susceptibility to NSCLC. Plasma levels of sPD-L1 are significantly increased in NSCLC patients, especially those with adenocarcinoma.

Novel biomarkers of abdominal aortic aneurysm disease: identifying gaps and dispelling misperceptions

Abdominal aortic aneurysm (AAA) is a prevalent and potentially life-threatening disease. Early detection by screening programs and subsequent surveillance has been shown to be effective at reducing the risk of mortality due to aneurysm rupture. The aim of this review is to summarize the developments in the literature concerning the latest biomarkers (from 2008 to date) and their potential screening and therapeutic values. Our search included human studies in English and found numerous novel biomarkers under research, which were categorized in 6 groups. Most of these studies are either experimental or hampered by their low numbers of patients. We concluded that currently no specific laboratory markers allow screeing for the disease and monitoring its progression or the results of treatment. Further studies and studies in larger patient groups are required in order to validate biomarkers as cost-effective tools in the AAA disease.

MicroRNA expression signature in human abdominal aortic aneurysms

BACKGROUND

Abdominal aortic aneurysm (AAA) is a dilatation of the aorta affecting most frequently elderly men. Histologically AAAs are characterized by inflammation, vascular smooth muscle cell apoptosis, and extracellular matrix degradation. The mechanisms of AAA formation, progression, and rupture are currently poorly understood. A previous mRNA expression study revealed a large number of differentially expressed genes between AAA and non-aneurysmal control aortas. MicroRNAs (miRNAs), small non-coding RNAs that are post-transcriptional regulators of gene expression, could provide a mechanism for the differential expression of genes in AAA.

METHODS

To determine differences in miRNA levels between AAA (n = 5) and control (n = 5) infrarenal aortic tissues, a microarray study was carried out. Results were adjusted using Benjamini-Hochberg correction (adjusted p < 0.05). Real-time quantitative RT-PCR (qRT-PCR) assays with an independent set of 36 AAA and seven control tissues were used for validation. Potential gene targets were retrieved from miRNA target prediction databases Pictar, TargetScan, and MiRTarget2. Networks from the target gene set were generated and examined using the network analysis programs, CytoScape® and Ingenuity Pathway Core Analysis®.

RESULTS

A microarray study identified eight miRNAs with significantly different expression levels between AAA and controls (adjusted p < 0.05). Real-time qRT-PCR assays validated the findings for five of the eight miRNAs. A total of 222 predicted miRNA target genes known to be differentially expressed in AAA based on a prior mRNA microarray study were identified. Bioinformatic analyses revealed that several target genes are involved in apoptosis and activation of T cells.

CONCLUSIONS

Our genome-wide approach revealed several differentially expressed miRNAs in human AAA tissue suggesting that miRNAs play a role in AAA pathogenesis.

Circulating soluble CTLA-4 is related to inflammatory markers in the 70 year old population

OBJECTIVE

Measurement of inflammatory mediators is an important tool to assess inflammation. We have, therefore, conducted a survey within the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study to evaluate the inter-relationship between soluble CTLA-4 (sCTLA-4) and other inflammatory markers.

MATERIALS AND METHODS

This is a population-based study, designed to quantify the circulating serum levels of sCTLA-4 and other inflammatory markers such as CRP and pro-inflammatory cytokines and chemokines by in-house ELISA, Immuno-turbidimetry and multiplex ELISA, respectively. A total of 1016 Swedish Caucasians aged 70 years old were recruited. The statistical analysis was performed by ANOVA.

RESULTS

The levels of sCTLA-4 were directly related to the levels of pro-inflammatory cytokines such as IL-6, IL-1alpha, IL-1beta, TNF-alpha, IFN-gamma and chemokines such as IL-8. However, the levels of sCTLA-4 were inversely related to the levels of MCP-1. Also, we could not demonstrate any relation between the levels of sCTLA-4 and CRP or soluble adhesion molecules.

CONCLUSIONS

Circulating sCTLA-4 could be used as a biomarker for inflammation, potentially reflecting dysregulated T lymphocytes.

CTLA4 -1661A/G and 3'UTR long repeat polymorphisms are associated with ulcerative colitis and influence CTLA4 mRNA and protein expression

Reduced cytotoxic T-lymphocyte antigen 4 (CTLA4) expression has been proposed as a risk for autoimmunity. CTLA4 polymorphisms have been associated with several autoimmune diseases, including ulcerative colitis (UC). In this study, we performed genotyping for CTLA4 -1661A/G, -1722T/C and 3' untranslated region (AT)n repeat polymorphisms in 300 Chinese UC patients and in 700 healthy controls, and evaluated the effects of polymorphisms on full-length (flCTLA4) and soluble CTLA4 (sCTLA4) expression in UC patients. The frequency of the -1661G allele was higher in UC patients than in healthy controls (16.5 vs 11.4%, P=0.003, odds ratio (OR)=1.53, 95% confidence interval (95% CI): 1.17-2.01). The prevalence of (AT)n repeats of the CTLA4 gene carrying long alleles (≥116 bp) was more common in UC patients than in healthy controls (22.0 vs 6.3%, P<0.001, OR=4.21, 95% CI: 2.79-6.33), and was associated with extensive colitis (P=0.008). Among UC patients, long-allele carriers expressed lower levels of flCTLA4 and sCTLA4 mRNA and sCTLA4 protein than did short-allele carriers (P<0.001, P<0.001, P<0.001, respectively). CTLA4 gene -1661A/G and long 3' untranslated region (AT)n repeat polymorphisms are associated with UC in Central China. This is likely from decreased expressions of sCTLA4 mRNA and sCTLA4 protein. Our study suggests that CTLA4 has an important role in susceptibility for UC in Central China.