Reduction in CD16/CD56 and CD16/CD3/CD56 Natural Killer Cells in Coronary Artery Disease

Overexpression of circulating CD38+ NK cells in colorectal cancer was associated with lymph node metastasis and poor prognosis

Introduction

Lymph node metastasis (LNM) is a critical prognostic factor for colorectal cancer (CRC). Due to the potential influence of immune system on CRC progression, investigation into lymphocyte subsets as clinical markers has gained attention. The objective of this study was to assess the capability of lymphocyte subsets in evaluating the lymph node status and prognosis of CRC.

Methods

Lymphocyte subsets, including T cells (CD3+), natural killer cells (NK, CD3- CD56+), natural killer-like T cells (NK-like T, CD3+ CD56+), CD38+ NK cells (CD3- CD56+ CD38+) and CD38+ NK-like T cells (CD3+ CD56+ CD38+), were detected by flow cytometry. Univariate and multivariate analyses were used to assess the risk factors of LNM. The prognostic role of parameters was evaluated by survival analysis.

Results

The proportion of CD38+ NK cells within the NK cell population was significantly higher in LNM-positive patients (p <0.0001). However, no significant differences were observed in the proportions of other lymphocyte subsets. Poorer histologic grade (odds ratio [OR] =4.76, p =0.03), lymphovascular invasion (LVI) (OR =22.38, p <0.01), and CD38+ NK cells (high) (OR =4.54, p <0.01) were identified as independent risk factors for LNM. Furthermore, high proportion of CD38+ NK cells was associated with poor prognosis of CRC patients (HR=2.37, p =0.03).

Conclusions

It was demonstrated that the proportion of CD38+ NK cells was a marker overexpressed in LNM-positive patients compared with LNM-negative patients. Moreover, an elevated proportion of CD38+ NK cells is a risk factor for LNM and poor prognosis in CRC.

CD8+ T and NK cells characterized by upregulation of NPEPPS and ABHD17A are associated with the co-occurrence of type 2 diabetes and coronary artery disease

Background

Coronary artery disease (CAD) and type 2 diabetes mellitus (T2DM) are closely related. The function of immunocytes in the pathogenesis of CAD and T2DM has not been extensively studied. The quantitative bioinformatics analysis of the public RNA sequencing database was applied to study the key genes that mediate both CAD and T2DM. The biological characteristics of associated key genes and mechanism of CD8+ T and NK cells in CAD and T2DM are our research focus.

Methods

With expression profiles of GSE66360 and GSE78721 from the Gene Expression Omnibus (GEO) database, we identified core modules associated with gene co-expression relationships and up-regulated genes in CAD and T2DM using Weighted Gene Co-expression Network Analysis (WGCNA) and the 'limma' software package. The enriched pathways of the candidate hub genes were then explored using GO, KEGG and GSEA in conjunction with the immune gene set (from the MSigDB database). A diagnostic model was constructed using logistic regression analysis composed of candidate hub genes in CAD and T2DM. Univariate Cox regression analysis revealed hazard ratios (HRs), 95% confidence intervals (CIs), and p-values for candidate hub genes in diagnostic model, while CIBERSORT and immune infiltration were used to assess the immune microenvironment. Finally, monocytes from peripheral blood samples and their immune cell ratios were analyzed by flow cytometry to validate our findings.

Results

Sixteen candidate hub genes were identified as being correlated with immune infiltration. Univariate Cox regression analysis revealed that NPEPPS and ABHD17A were highly correlated with the diagnosis of CAD and T2DM. The results indicate that CD8+ T cells (p = 0.04) and NKbright cells (p = 3.7e-3) are significantly higher in healthy controls than in individuals with CAD or CAD combined with T2DM. The bioinformatics results on immune infiltration were well validated by flow cytometry.

Conclusions

A series of bioinformatics studies have shown ABHD17A and NPEPPS as key genes for the co-occurrence of CAD and T2DM. Our study highlights the important effect of CD8+ T and NK cells in the pathogenesis of both diseases, indicating that they may serve as viable targets for diagnosis and therapeutic intervention.

Mass cytometry analysis reveals altered immune profiles in patients with coronary artery disease

Objective

The importance of inflammation in atherosclerosis is well accepted, but the role of the adaptive immune system is not yet fully understood. To further explore this, we assessed the circulating immune cell profile of patients with coronary artery disease (CAD) to identify discriminatory features by mass cytometry.

Methods

Mass cytometry was performed on patient samples from the BioHEART-CT study, gated to detect 82 distinct cell subsets. CT coronary angiograms were analysed to categorise patients as having CAD (CAD+) or having normal coronary arteries (CAD-).

Results

The discovery cohort included 117 patients (mean age 61 ± 12 years, 49% female); 79 patients (68%) were CAD+. Mass cytometry identified changes in 15 T-cell subsets, with higher numbers of proliferating, highly differentiated and cytotoxic cells and decreases in naïve T cells. Five T-regulatory subsets were related to an age and gender-independent increase in the odds of CAD incidence when expressing CCR2 (OR 1.12), CCR4 (OR 1.08), CD38 and CD45RO (OR 1.13), HLA-DR (OR 1.06) and Ki67 (OR 1.22). Markers of proliferation and differentiation were also increased within B cells, while plasmacytoid dendritic cells were decreased. This combination of changes was assessed using SVM models in discovery and validation cohorts (area under the curve = 0.74 for both), confirming the robust nature of the immune signature detected.

Conclusion

We identified differences within immune subpopulations of CAD+ patients which are indicative of a systemic immune response to coronary atherosclerosis. This immune signature needs further study via incorporation into risk scoring tools for the precision diagnosis of CAD.

The Increased TIGIT-Expressing CD3+CD56+ Cells Are Associated with Coronary Artery Disease and Its Inflammatory Environment

We aimed to examine the correlation of T-cell immunoglobulin and ITIM domain (TIGIT)-expressing CD3 + CD56 + cells (TNKS) with coronary artery disease (CAD), atherosclerotic lesion progression, and inflammatory environment. A total of 199 subjects, including 98 patients with acute coronary syndrome (ACS), 52 patients with chronic coronary syndrome (CCS), and 49 control subjects, were recruited in the study. The TIGIT-expressing TNKS were quantified by flow cytometric analysis; the severity of coronary artery lesions was evaluated by the Gensini score. Whole blood cells were stimulated with interleukin-2 (IL-2), interleukin-7 (IL-7), and interleukin-15 (IL-15) in presence or absence of STAT, PI3K, and P38 MAPK inhibitors, respectively. The TIGIT-expressing TNKS was significantly increased in patients with CAD, ACS, and CCS compared to the control group (P < 0.05). The TIGIT-expressing TNKS were independent predictors of CAD, ACS and CCS (P < 0.05). The TIGIT-expressing TNKS were positively associated with Gensini score (P < 0.05). The TIGIT-expressing TNKS was positively correlated with age, and being male (P < 0.05). The inflammatory microenviroment with increased IL-2, IL-7, and IL-15 contributed to upregulation of TIGIT expression in TNKS. PI3K and P38 MAPK inhibitors could inhibit the upregulation of TIGIT expression in TNKS induced by IL-2, IL-7, and IL-15. The TIGIT-expressing TNKS may be involved in common pathogenesis of ACS and CCS, and atherosclerotic lesion progression. Meanwhile, the increased TIGIT-expressing TNKS might be associated with a proatherogenic microenvironment or inflammatory microenvironment. PI3K and P38 MAPK signaling pathways were involved in the regulation of TIGIT expression.

Epithelial-mesenchymal transition-related genes in coronary artery disease

Epithelial-mesenchymal transition (EMT) is critical in the development of coronary artery disease (CAD). However, landscapes of EMT-related genes have not been fully established in CAD. We identified the differentially expressed mRNAs and lncRNAs (DElncRNAs) from the Gene Expression Omnibus database. Pearson’s correlation analysis, the least absolute shrinkage and selection operator regression, and support vector machine reverse feature elimination algorithms were used to screen EMT-related lncRNAs. The cis–trans regulatory networks were constructed based on EMT-related lncRNAs. Quantitative real-time polymerase chain reaction was performed to validate the expression of EMT-related genes in a cohort of six patients with CAD and six healthy controls. We further estimated the infiltration of the immune cells in CAD patients with five algorithms, and the correlation between EMT-related genes and infiltrating immune cells was analyzed. We identified eight EMT-related lncRNAs in CAD. The area under curve value was greater than 0.95. The immune analysis revealed significant CD8 T cells, monocytes, and NK cells in CAD and found that EMT-related lncRNAs were correlated with these immune cell subsets. Moreover, SNAI2, an EMT-TF gene, was found in the trans-regulatory network of EMT-related lncRNAs. Further, we found SNAI2 as a biomarker for the diagnosis of CAD but it also had a close correlation with immune cell subsets in CAD. Eight EMT-related lncRNAs and SNAI2 have important significance in the diagnosis of CAD patients.

The Activating Receptors of Natural Killer Cells and Their Inter-Switching Potentials

The global incidence of cancer is on the increase and researchers are prospecting for specific and non-selective therapies derived from the immune system. The killer activating receptors of NK cells are known to be involved in immunosurveillance against tumor and virally-infected cells. These receptors belong to two main categories, namely the immunoglobulin like and C-lectin like families. Though they have different signal pathways, all the killer activating receptors have similar effector functions which include direct cytotoxicity and the release of inflammatory cytokines such as IFN-gamma and TNF-alpha. To transduce signals that exceed the activation threshold for cytotoxicity, most of these receptors require synergistic effort. This review profiles 21 receptors: 13 immunoglobulin-like, 5 lectin-like, and 3 others. It critically explores their structural uniqueness, role in disease, respective transduction signal pathways and their status as current and prospective targets for cancer immunotherapy. While the native ligands of most of these receptors are known, much work is required to prospect for specific antibodies, peptides and multi-target small molecules with high binding affinities.

Identification of novel cardiovascular disease associated metabolites using untargeted metabolomics

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality around the world. Early diagnosis of CVD could provide the opportunity for sensible management and better clinical outcome along with the prevention of further progression of the disease. In the current study, we used an untargeted metabolomic approach to identify possible metabolite(s) that associate well with the CVD and could serve either as therapeutic target or disease-associated metabolite. We identified 26 rationally adjusted unique metabolites that were differentially present in the serum of CVD patients compared with healthy individuals, among them 15 were found to be statistically significant. Out of these metabolites, we identified some novel metabolites like UDP-l-rhamnose and N1-acetylspermidine that have not been reported to be linked with CVD directly. Further, we also found that some metabolites like ethanolamide, solanidine, dimethylarginine, N-acetyl-l-tyrosine, can act as a discriminator of CVD. Metabolites integrating pathway enrichment analysis showed enrichment of various important metabolic pathways like histidine metabolism, methyl histidine metabolism, carnitine synthesis, along with arginine and proline metabolism in CVD patients. Our study provides a great opportunity to understand the pathophysiological role and impact of the identified unique metabolites and can be extrapolated as specific CVD specific metabolites.

Single-Cell Immune Profiling in Coronary Artery Disease: The Role of State-of-the-Art Immunophenotyping With Mass Cytometry in the Diagnosis of Atherosclerosis

Coronary artery disease remains the leading cause of death globally and is a major burden to every health system in the world. There have been significant improvements in risk modification, treatments, and mortality; however, our ability to detect asymptomatic disease for early intervention remains limited. Recent discoveries regarding the inflammatory nature of atherosclerosis have prompted investigation into new methods of diagnosis and treatment of coronary artery disease. This article reviews some of the highlights of the important developments in cardioimmunology and summarizes the clinical evidence linking the immune system and atherosclerosis. It provides an overview of the major serological biomarkers that have been associated with atherosclerosis, noting the limitations of these markers attributable to low specificity, and then contrasts these serological markers with the circulating immune cell subtypes that have been found to be altered in coronary artery disease. This review then outlines the technique of mass cytometry and its ability to provide high-dimensional single-cell data and explores how this high-resolution quantification of specific immune cell subpopulations may assist in the diagnosis of early atherosclerosis in combination with other complimentary techniques such as single-cell RNA sequencing. We propose that this improved specificity has the potential to transform the detection of coronary artery disease in its early phases, facilitating targeted preventative approaches in the precision medicine era.

Effects of the age/rage axis in the platelet activation

Platelet activity is essential in cardiovascular diseases. Therefore our objective was to evaluate the main effects of activating RAGE in platelets which are still unknown. A search for RAGE expression in different databases showed poor or a nonexistent presence in platelets. We confirmed the expression in platelets and secreted variable of RAGE (sRAGE). Platelets from elderly adults expressed in resting showed 3.2 fold more RAGE from young individuals (p < 0.01) and 3.3 fold with TRAP-6 (p < 0.001). These results could indicate that the expression of RAGE is more inducible in older adults. Then we found that activating RAGE with AGE-BSA-derived from methylglyoxal and subthreshold TRAP-6, showed a considerable increase with respect to the control in platelet aggregation and expression of P-selectin (respectively, p < 0.01). This effect was almost completely blocked by using a specific RAGE inhibitor (FSP-ZM1), confirming that RAGE is important for the function and activation platelet. Finally, we predict the region stimulated by AGE-BSA is located in region V of RAGE and 13 amino acids are critical for its binding. In conclusion, the activation of RAGE affects platelet activation and 13 amino acids are critical for its stimulation, this information is crucial for future possible treatments for CVD.

Immune cell phenotyping in low blood volumes for assessment of cardiovascular disease risk, development, and progression: a pilot study

Background

Cardiovascular disease (CVD) is the leading cause of death in the world. Given the role of immune cells in atherosclerosis development and progression, effective methods for characterizing immune cell populations are needed, particularly among populations disproportionately at risk for CVD.

Results

By using a variety of antibodies combined in one staining protocol, we were able to identify granulocyte, lymphocyte, and monocyte sub-populations by CD-antigen expression from 500 µl of whole blood, enabling a more extensive comparison than what is possible with a complete blood count and differential (CBC). The flow cytometry panel was established and tested in a total of 29 healthy men and women. As a proof of principle, these 29 samples were split by their race/ethnicity: African-Americans (AA) (N = 14) and Caucasians (N = 15). We found in accordance with the literature that AA had fewer granulocytes and more lymphocytes when compared to Caucasians, though the proportion of total monocytes was similar in both groups. Several new differences between AA and Caucasians were noted that had not been previously described. For example, AA had a greater proportion of platelet adhesion on non-classical monocytes when compared to Caucasians, a cell-to-cell interaction described as crucially important in CVD. We also examined our flow panel in a clinical population of AA women with known CVD risk factors (N = 20). Several of the flow cytometry parameters that cannot be measured with the CBC displayed correlations with clinical CVD risk markers. For instance, Framingham Risk Score (FRS) calculated for each participant correlated with immune cell platelet aggregates (PA) (e.g. T cell PA β = 0.59, p = 0.03 or non-classical monocyte PA β = 0.54, p = 0.02) after adjustment for body mass index (BMI).

Conclusion

A flow cytometry panel identified differences in granulocytes, monocytes, and lymphocytes between AA and Caucasians which may contribute to increased CVD risk in AA. Moreover, this flow panel identifies immune cell sub-populations and platelet aggregates associated with CVD risk. This flow cytometry panel may serve as an effective method for phenotyping immune cell populations involved in the development and progression of CVD.

Interruption of Autophagosome Formation in Cardiovascular Disease, an Evidence for Protective Response of Autophagy

BACKGROUND

A heart attack occurs when coronary artery blockage interrupts the blood supply to the heart such as is seen in cardiovascular disease (CVD). Importantly, autophagy is commonly regarded as a host defense mechanism against microbial invaders.

METHODS

A total of 50 blood samples were obtained from cardiovascular (CV) patients in addition to 30 samples that were obtained from healthy individuals and served as controls. Macrophages were isolated in vitro and propagated from the blood samples. Autophagosome formation, cytokine secretion, and apolipoprotein B (ApoB) gene expression were monitored in patient samples and their derived macrophages.

RESULTS

The results showed that autophagy-related (Atg) LC3 and Atg5 genes were significantly down-regulated in all samples obtained from CV patients. Furthermore, the relative gene expression of ApoB, which plays the major role in lipoprotein metabolism, was significantly increased in CV patients. Interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) levels were increased in these blood samples. Interestingly, targeting of ApoB by small interference RNA (siRNA) reduced the production levels of low-density lipoprotein (LDL), IL-6 and TNF-α in patient-derived macrophages. Further, treatment of patient-derived macrophages with rapamycin, an autophagy inducer agent, successfully regulated the production of LDL, IL-6, TNF-α, and ApoB expression via activation of autophagosome formation.

CONCLUSION

The current data reveal the potential disturbance of autophagy in CV patients that accompanied ApoB over-expression. Furthermore, our findings provide evidence for the protective role of autophagy in accumulation of pro-inflammatory cytokines and intracellular LDL degradation in CV patient-derived macrophages.

Characterization of Natural Killer Cells in HIV Patients Beginning Therapy with a High Burden of Cytomegalovirus

BACKGROUND

Active infections with cytomegalovirus (CMV) increase NK cell expression of the inhibitory receptor LIR-1 and the activating receptor NKG2C in transplant recipients. However, the effects of CMV on NK cells are different in HIV patients stable on antiretroviral therapy (ART) and have not been analyzed in young HIV patients beginning ART.

METHODOLOGY

We followed a cohort of 78 Indonesian HIV patients beginning ART. CMV antibodies were measured in plasma before ART (baseline), and after 1, 3, 6, and 12 months. CMV DNA was sought in blood granulocytes at baseline by quantitative PCR assay and a deletion in the NKG2C gene was identified by PCR. NK cell profiles were monitored by flow cytometry in 19 patients stratified by the presence of CMV DNA. Healthy controls (n = 17) were assessed once.

RESULTS

All 78 patients were CMV seropositive and 41 had detectable CMV DNA. CMV DNA+ patients had higher proportions of total NK cells and CD16⁺ NK cells at baseline, but similar expression of LIR-1 and NKp30 on NK cells on ART. However, levels of CMV antibody were inversely related to median LIR-1 expression on NK cells. A dramatic elevation in cells expressing NKG2C was restricted to CMV DNA+ patients heterozygous for the NKG2C deletion. Patients with High NKG2C expression had lower levels of CMV antibodies.

CONCLUSION

A subpopulation of NK cells expressing NKG2C was induced by CMV replication in HIV patients heterozygous for a deletion in this gene. Individuals with an abundant NKG2C⁺ and LIR-1⁺ NK cells displayed lower levels of CMV reactive antibody.

Decrease in the Frequency of Circulating CD56+CD161+ NK Cells in Human Visceral Leishmaniasis

BACKGROUND

Natural Killer (NK) cell plays an important role in the innate immune system and is known to produce IFN-γ at an early stage of infection that is essential to eliminate intracellular infection like Leishmania spp. It is already established that Leishmania parasite inhibits the activity of NK cells, avoiding the encounter with the early innate immune response. This, in turn, favors establishment and further dissemination of the infection.

METHODS

In the present study, we have tried to measure the frequency of different phenotypic subsets of NK cells among visceral leishmaniasis (VL) patients.

RESULTS

We have phenotyped three distinct three distinct subsets (CD56^-CD161⁺, CD56⁺CD161^-, and CD56⁺CD161⁺) of NK (CD3^-) cell using their specific markers CD161 and CD56.

CONCLUSION

Interestingly, we observed selective loss of CD56⁺CD161⁺ subset of circulating NK (CD3^-) cells. Importantly, the other subsets (i.e., CD56^-CD161⁺ and CD56⁺CD161^-) of circulating NK cells remain unaffected as compared with healthy subjects.