Effector Memory T cells Are Associated With Atherosclerosis in Humans and Animal Models

Systematic review and quantitative meta-analysis of age-dependent human T-lymphocyte homeostasis

Objective

To evaluate and quantitatively describe age-dependent homeostasis for a broad range of total T-cells and specific T-lymphocyte subpopulations in healthy human subjects.

Methods

A systematic literature review was performed to identify and collect relevant quantitative information on T-lymphocyte counts in human blood and various organs. Both individual subject and grouped (aggregated) data on T-lymphocyte observations in absolute and relative values were digitized and curated; cell phenotypes, gating strategies for flow cytometry analyses, organs from which observations were obtained, subjects' number and age were also systematically inventoried. Age-dependent homeostasis of each T-lymphocyte subpopulation was evaluated via a weighted average calculation within pre-specified age intervals, using a piece-wise equal-effect meta-analysis methodology.

Results

In total, 124 studies comprising 11722 unique observations from healthy subjects encompassing 20 different T-lymphocyte subpopulations - total CD45+ and CD3+ lymphocytes, as well as specific CD4+ and CD8+ naïve, recent thymic emigrants, activated, effector and various subpopulations of memory T-lymphocytes (total-memory, central-memory, effector-memory, resident-memory) - were systematically collected and included in the final database for a comprehensive analysis. Blood counts of most T-lymphocyte subpopulations demonstrate a decline with age, with a pronounced decrease within the first 10 years of life. Conversely, memory T-lymphocytes display a tendency to increase in older age groups, particularly after ~50 years of age. Notably, an increase in T-lymphocyte numbers is observed in neonates and infants (0 - 1 year of age) towards less differentiated T-lymphocyte subpopulations, while an increase into more differentiated subpopulations emerges later (1 - 5 years of age).

Conclusion

A comprehensive systematic review and meta-analysis of T-lymphocyte age-dependent homeostasis in healthy humans was performed, to evaluate immune T-cell profiles as a function of age and to characterize generalized estimates of T-lymphocyte counts across age groups. Our study introduces a quantitative description of the fundamental parameters characterizing the maintenance and evolution of T-cell subsets with age, based on a comprehensive integration of available organ-specific and systems-level flow cytometry datasets. Overall, it provides the most up-to-date view of physiological T-cell dynamics and its variance and may be used as a consistent reference for gaining further mechanistic understanding of the human immune status in health and disease.

Association of T-Cell Phenotypes With Peri-Coronary Inflammation in People With and Without HIV and Without Cardiovascular Disease

BACKGROUND

Persistent immune activation is linked to elevated cardiovascular diseases in people with HIV on antiretroviral therapy. The fat attenuation index (FAI) is a measure of peri-coronary inflammation that independently predicts cardiovascular disease risk in people without HIV. Whether FAI is associated with immune activation is unknown.

METHODS

Peripheral blood T-cell activation and homing phenotypes were measured in people with HIV (n=58) and people without HIV (n=16) without known cardiovascular disease who underwent coronary computed tomography angiography and had FAI measurements. A cross-sectional analysis of an observational cohort was performed. The primary aim was to evaluate associations of T-cell activation and phenotypes with the outcome variables, FAI values of the right coronary artery and left anterior descending artery, which were assessed using multivariable regression models adjusted for age, natal sex, race, low-density lipoprotein cholesterol, body mass index, and use of lipid-lowering medication.

RESULTS

T cells from people with HIV showed greater activation, as measured by cluster of differentiation (CD) 38/human leukocyte antigen - DR isotype coexpression on CD4 central memory and terminally-differentiated effector memory subsets and on CD8 effector memory (TEM), than did cells from people without HIV. Expression of the chemokine receptor C-C Chemokine Receptor 2 was reduced on CD4 central memory and TEM and CD8 TEM and terminally-differentiated effector memory subsets in people with HIV. Among all participants, PD-1 (programmed cell death 1) in CD8 central memory was associated with worsened peri-coronary inflammation of the right coronary artery, whereas perforin/granzyme B on CD8 TEM was associated with improved peri-coronary inflammation of the right coronary artery and left anterior descending artery in adjusted analyses. When accounting for HIV serostatus, CD38/human leukocyte antigen - DR isotype coexpression on CD8 central memory, TEM, and terminally-differentiated effector memory cells was associated with more peri-coronary inflammation of the left anterior descending artery.

CONCLUSIONS

The associations between T-cell activation with FAI are novel and suggest that T-cell activation may be an important driver of peri-coronary inflammation, occurring at an early stage of atherosclerosis, even before the development of clinical disease.

Transient High Salt Intake Promotes T-Cell-Mediated Hypertensive Vascular Injury

BACKGROUND

Dietary high salt (HS) intake has a strong impact on cardiovascular diseases. Here, we investigated the link between HS-aggravated immune responses and the development of hypertensive vascular disease.

METHODS

ApolipoproteinE-deficient mice were transiently treated with HS (1% NaCl) via drinking water for 2 weeks, followed by a washout period, and subsequent Ang II (angiotensin II) infusion (1000 ng/kg per min for 10 days) to induce abdominal aortic aneurysms/dissections and inflammation.

RESULTS

While transient HS intake alone triggered nonpathologic infiltration of activated T cells into the aorta, subsequent Ang II infusion increased mortality and the incidence of abdominal aortic aneurysms/dissections and atherosclerosis compared with hypertensive control mice. There were no differences in blood pressure between both groups. In transient HS-treated hypertensive mice, the aortic injury was associated with increased inflammation, accumulation of neutrophils, monocytes, CD69+CD4+ T cells, as well as CD4+ and CD8+ memory T cells. Mechanistically, transient HS intake increased expression levels of aortic RORγt as well as splenic CD4+TH17 and CD8+TC1 T cells in Ang II-treated mice. Isolated aortas of untreated mice were incubated with supernatants of TH17, TH1, or TC1 cells polarized in vitro under HS or normal conditions which revealed that secreted factors of HS-differentiated TH17 and TC1 cells, but not TH1 cells accelerated endothelial dysfunction.

CONCLUSIONS

Our data suggest that transient HS intake induces a subclinical T-cell-mediated aortic immune response, which is enhanced by Ang II. We propose a 2-hit model, in which HS acts as a predisposing factor to enhance hypertension-induced TH17 and TC1 polarization and aortic disease.

Immunoproteasomal Inhibition With ONX-0914 Attenuates Atherosclerosis and Reduces White Adipose Tissue Mass and Metabolic Syndrome in Mice

BACKGROUND

Atherosclerosis is the major underlying pathology of cardiovascular disease and is driven by dyslipidemia and inflammation. Inhibition of the immunoproteasome, a proteasome variant that is predominantly expressed by immune cells and plays an important role in antigen presentation, has been shown to have immunosuppressive effects.

METHODS

We assessed the effect of ONX-0914, an inhibitor of the immunoproteasomal catalytic subunits LMP7 (proteasome subunit β5i/large multifunctional peptidase 7) and LMP2 (proteasome subunit β1i/large multifunctional peptidase 2), on atherosclerosis and metabolism in LDLr-/- and APOE*3-Leiden.CETP mice.

RESULTS

ONX-0914 treatment significantly reduced atherosclerosis, reduced dendritic cell and macrophage levels and their activation, as well as the levels of antigen-experienced T cells during early plaque formation, and Th1 cells in advanced atherosclerosis in young and aged mice in various immune compartments. Additionally, ONX-0914 treatment led to a strong reduction in white adipose tissue mass and adipocyte progenitors, which coincided with neutrophil and macrophage accumulation in white adipose tissue. ONX-0914 reduced intestinal triglyceride uptake and gastric emptying, likely contributing to the reduction in white adipose tissue mass, as ONX-0914 did not increase energy expenditure or reduce total food intake. Concomitant with the reduction in white adipose tissue mass upon ONX-0914 treatment, we observed improvements in markers of metabolic syndrome, including lowered plasma triglyceride levels, insulin levels, and fasting blood glucose.

CONCLUSIONS

We propose that immunoproteasomal inhibition reduces 3 major causes underlying cardiovascular disease, dyslipidemia, metabolic syndrome, and inflammation and is a new target in drug development for atherosclerosis treatment.

T Cells in Atherosclerosis: Key Players in the Pathogenesis of Vascular Disease

Atherosclerosis is a chronic inflammatory disease characterized by the accumulation of lipid-rich plaques within arterial walls. T cells play a pivotal role in the pathogenesis of atherosclerosis in which they help orchestrate immune responses and contribute to plaque development and instability. Here, we discuss the recognition of atherosclerosis-related antigens that may trigger T cell activation together with additional signaling from co-stimulatory molecules and lesional cytokines. Although few studies have indicated candidates for the antigen specificity of T cells in atherosclerosis, further research is needed. Furthermore, we describe the pro-atherogenic and atheroprotective roles of diverse subsets of T cells such as CD4+ helper, CD8+ cytotoxic, invariant natural killer, and γδ T cells. To classify and quantify T cell subsets in atherosclerosis, we summarize current methods to analyze cellular heterogeneity including single cell RNA sequencing and T cell receptor (TCR) sequencing. Further insights into T cell biology will help shed light on the immunopathology of atherosclerosis, inform potential therapeutic interventions, and pave the way for precision medicine approaches in combating cardiovascular disease.

Adipocytes control hematopoiesis and inflammation through CD40 signaling

The co-stimulatory CD40-CD40L dyad plays an important role in chronic inflammatory diseases associated with aging. Although CD40 is mainly expressed by immune cells, CD40 is also present on adipocytes. We aimed to delineate the role of adipocyte CD40 in the aging hematopoietic system and evaluated the effects of adipocyte CD40 deficiency on cardiometabolic diseases. Adult adipocyte CD40-deficient mice (AdiCD40KO) mice had a decrease in bone marrow hematopoietic stem cells (Lin-Sca+cKit+, LSK) and common lymphoid progenitors, which was associated with increased bone marrow adiposity and T-cell activation, along with elevated plasma corticosterone levels, a phenotype that became more pronounced with age. Atherosclerotic AdiCD40koApoE-/- (CD40AKO) mice also displayed changes in the LSK population, showing increased myeloid and lymphoid multipotent progenitors, and augmented corticosterone levels. Increased T-cell activation could be observed in bone marrow, spleen, and adipose tissue, while the numbers of B cells were decreased. Although atherosclerosis was reduced in CD40AKO mice, plaques contained more activated T cells and larger necrotic cores. Analysis of peripheral adipose tissue in a diet-induced model of obesity revealed that obese AdiCD40KO mice had increased T-cell activation in adipose tissue and lymphoid organs, but decreased weight gain and improved insulin sensitivity, along with increased fat oxidation. In conclusion, adipocyte CD40 plays an important role in maintaining immune cell homeostasis in bone marrow during aging and chronic inflammatory diseases, particularly of the lymphoid populations. Although adipocyte CD40 deficiency reduces atherosclerosis burden and ameliorates diet-induced obesity, the accompanying T-cell activation may eventually aggravate cardiometabolic diseases.

Impaired tolerance to the autoantigen LL-37 in acute coronary syndrome

Background

LL-37 is the only member of the cathelicidin family of antimicrobial peptides in humans and is an autoantigen in several autoimmune diseases and in acute coronary syndrome (ACS). In this report, we profiled the specific T cell response to the autoimmune self-antigen LL-37 and investigated the factors modulating the response in peripheral blood mononuclear cells (PBMCs) of healthy subjects and ACS patients.

Methods and results

The activation induced marker (AIM) assay demonstrated differential T cell profiles characterized by the persistence of CD134 and CD137, markers that impair tolerance and promote immune effector and memory response, in ACS compared to Controls. Specifically, CD8+CD69+CD137+ T cells were significantly increased by LL-37 stimulation in ACS PBMCs. T effector cell response to LL-37 were either HLA dependent or independent as determined by blocking with monoclonal antibody to either Class-I HLA or Class-II HLA. Blocking of immune checkpoints PD-1 and CTLA-4 demonstrated the control of self-reactive T cell response to LL-37 was modulated predominantly by CTLA-4. Platelets from healthy controls down-modulated CD8+CD69+CD137+ T cell response to LL-37 in autologous PBMCs. CD8+CD69+CD137+ T cell AIM profile negatively correlated with platelet count in ACS patients.

Conclusions

Our report demonstrates that the immune response to the autoantigen LL-37 in ACS patients is characterized specifically by CD8+CD69+CD137+ T cell AIM profile with persistent T cell activation and the generation of immunologic memory. The results provide potentially novel insight into mechanistic pathways of antigen-specific immune signaling in ACS.

CAR-T Cells with Phytohemagglutinin (PHA) Provide Anti-Cancer Capacity with Better Proliferation, Rejuvenated Effector Memory, and Reduced Exhausted T Cell Frequencies

The development of genetic modification techniques has led to a new era in cancer treatments that have been limited to conventional treatments such as chemotherapy. intensive efforts are being performed to develop cancer-targeted therapies to avoid the elimination of non-cancerous cells. One of the most promising approaches is genetically modified CAR-T cell therapy. The high central memory T cell (Tcm) and stem cell-like memory T cell (Tscm) ratios in the CAR-T cell population increase the effectiveness of immunotherapy. Therefore, it is important to increase the populations of CAR-expressing Tcm and Tscm cells to ensure that CAR-T cells remain long-term and have cytotoxic (anti-tumor) efficacy. In this study, we aimed to improve CAR-T cell therapy's time-dependent efficacy and stability, increasing the survival time and reducing the probability of cancer cell growth. To increase the sub-population of Tcm and Tscm in CAR-T cells, we investigated the production of a long-term stable and efficient cytotoxic CAR-T cell by modifications in the cell activation-dependent production using Phytohemagglutinin (PHA). PHA, a lectin that binds to the membranes of T cells and increases metabolic activity and cell division, is studied to increase the Tcm and Tscm population. Although it is known that PHA significantly increases Tcm cells, B-lymphocyte antigen CD19-specific CAR-T cell expansion, its anti-cancer and memory capacity has not yet been tested compared with aCD3/aCD28-amplified CAR-T cells. Two different types of CARs (aCD19 scFv CD8-(CD28 or 4-1BB)-CD3z-EGFRt)-expressing T cells were generated and their immunogenic phenotype, exhausted phenotype, Tcm-Tscm populations, and cytotoxic activities were determined in this study. The proportion of T cell memory phenotype in the CAR-T cell populations generated by PHA was observed to be higher than that of aCD3/aCD28-amplified CAR-T cells with similar and higher proliferation capacity. Here, we show that PHA provides long-term and efficient CAR-T cell production, suggesting a potential alternative to aCD3/aCD28-amplified CAR-T cells.

Specific Loss of ABCA1 (ATP-Binding Cassette Transporter A1) Suppresses TCR (T-Cell Receptor) Signaling and Provides Protection Against Atherosclerosis

BACKGROUND

ABCA1 (ATP-binding cassette transporter A1) mediates cholesterol efflux to apo AI to maintain cellular cholesterol homeostasis. The current study aims to investigate whether T-cell-specific deletion of ABCA1 modulates the phenotype/function of T cells and the development of atherosclerosis.

METHODS

Mice with T-cell-specific deletion of ABCA1 on low-density lipoprotein receptor knockout (Ldlr^-/-) background (Abca1^CD4-/CD4-Ldlr^-/-) were generated by multiple steps of (cross)-breedings among Abca1^flox/flox, CD4-Cre, and Ldlr^-/- mice.

RESULTS

Deletions of ABCA1 greatly suppressed cholesterol efflux to apo AI but slightly reduced membrane lipid rafts on T cells probably due to the upregulation of ABCG1. Moreover, ABCA1 deficiency impaired TCR (T-cell receptor) signaling and inhibited the survival and proliferation of T cells as well as the formation of effector memory T cells. Despite the comparable levels of plasma total cholesterol after Western-type diet feeding, Abca1^CD4-/CD4-Ldlr^-/- mice showed significantly attenuated arterial accumulations of T cells and smaller atherosclerotic lesions than Abca1^+/+Ldlr^-/-controls, which were associated with reduced surface CCR5 (CC motif chemokine receptor 5) and CXCR3 (CXC motif chemokine receptor 3), decreased antiapoptotic Bcl-2 (B-cell lymphoma 2) and Bcl-xL (B-cell lymphoma extra-large), and hampered abilities to produce IL (interleukin)-2 and IFN (interferon)-γ by ABCA1-deficient T cells.

CONCLUSIONS

ABCA1 is essential for T-cell cholesterol homeostasis. Deletion of ABCA1 in T cells impairs TCR signaling, suppresses the survival, proliferation, differentiation, and function of T cells, thereby providing atheroprotection in vivo.

Immunological mechanisms of exercise therapy in dyslipidemia

Numerous studies demonstrated the strong link between dyslipidemia and the cardiovascular risk. Physical activity and exercise represent effective prevention and therapy strategies for dyslipidemia and at the same time counteract numerous comorbidities that often accompany the disease. The physiological mechanisms are manifold, and primary mechanisms might be an increased energy consumption and associated adaptations of the substrate metabolism. Recent studies showed that there are bidirectional interactions between dyslipidemia and the immune system. Thus, abnormal blood lipids may favor pro-inflammatory processes, and at the same time inflammatory processes may also promote dyslipidemia. Physical activity has been shown to affect numerous immunological processes and has primarily anti-inflammatory effects. These are manifested by altered leukocyte subtypes, cytokine patterns, stress protein expression, and by reducing hallmarks of immunosenescence. The aim of this review is to describe the effects of exercise on the treatment dyslipidemia and to discuss possible immunological mechanisms against the background of the current literature.

Crosstalk between dendritic cells and T lymphocytes during atherogenesis: Focus on antigen presentation and break of tolerance

Atherosclerosis is a chronic disease resulting from an impaired lipid and immune homeostasis, where the interaction between innate and adaptive immune cells leads to the promotion of atherosclerosis-associated immune-inflammatory response. Emerging evidence has suggested that this response presents similarities to the reactivity of effector immune cells toward self-epitopes, often as a consequence of a break of tolerance. In this context, dendritic cells, a heterogeneous population of antigen presenting cells, play a key role in instructing effector T cells to react against foreign antigens and T regulatory cells to maintain tolerance against self-antigens and/or to patrol for self-reactive effector T cells. Alterations in this delicate balance appears to contribute to atherogenesis. The aim of this review is to discuss different DC subsets, and their role in atherosclerosis as well as in T cell polarization. Moreover, we will discuss how loss of T cell tolerogenic phenotype participates to the immune-inflammatory response associated to atherosclerosis and how a better understanding of these mechanisms might result in designing immunomodulatory therapies targeting DC-T cell crosstalk for the treatment of atherosclerosis-related inflammation.

T cell cholesterol efflux suppresses apoptosis and senescence and increases atherosclerosis in middle aged mice

Atherosclerosis is a chronic inflammatory disease driven by hypercholesterolemia. During aging, T cells accumulate cholesterol, potentially affecting inflammation. However, the effect of cholesterol efflux pathways mediated by ATP-binding cassette A1 and G1 (ABCA1/ABCG1) on T cell-dependent age-related inflammation and atherosclerosis remains poorly understood. In this study, we generate mice with T cell-specific Abca1/Abcg1-deficiency on the low-density-lipoprotein-receptor deficient (Ldlr^-/-) background. T cell Abca1/Abcg1-deficiency decreases blood, lymph node, and splenic T cells, and increases T cell activation and apoptosis. T cell Abca1/Abcg1-deficiency induces a premature T cell aging phenotype in middle-aged (12-13 months) Ldlr^-/- mice, reflected by upregulation of senescence markers. Despite T cell senescence and enhanced T cell activation, T cell Abca1/Abcg1-deficiency decreases atherosclerosis and aortic inflammation in middle-aged Ldlr^-/- mice, accompanied by decreased T cells in atherosclerotic plaques. We attribute these effects to T cell apoptosis downstream of T cell activation, compromising T cell functionality. Collectively, we show that T cell cholesterol efflux pathways suppress T cell apoptosis and senescence, and induce atherosclerosis in middle-aged Ldlr^-/- mice.

Atherosclerosis and multi-organ-associated pathologies

Atherosclerosis is a chronic inflammatory disease of the vascular system that is characterized by the deposition of modified lipoproteins, accumulation of immune cells, and formation of fibrous tissue within the vessel wall. The disease occurs in vessels throughout the body and affects the functions of almost all organs including the lymphoid system, bone marrow, heart, brain, pancreas, adipose tissue, liver, kidneys, and gastrointestinal tract. Atherosclerosis and associated factors influence these tissues via the modulation of local vascular functions, induction of cholesterol-associated pathologies, and regulation of local immune responses. In this review, we discuss how atherosclerosis interferers with functions of different organs via several common pathways and how the disturbance of immunity in atherosclerosis can result in disease-provoking dysfunctions in multiple tissues. Our growing appreciation of the implication of atherosclerosis and associated microenvironmental conditions in the multi-organ pathology promises to influence our understanding of CVD-associated disease pathologies and to provide new therapeutic opportunities.

Atherosclerosis Impairs Naive CD4 T-Cell Responses via Disruption of Glycolysis

Objective

CD4 T cells are important regulators of atherosclerotic progression. The metabolic profile of CD4 T cells controls their signaling and function, but how atherosclerosis affects T-cell metabolism is unknown. Here, we sought to determine the impact of atherosclerosis on CD4 T-cell metabolism and the contribution of such metabolic alterations to atheroprogression.

Approach and Results

Using PCR arrays, we profiled the expression of metabolism genes in CD4 T cells from atherosclerotic apolipoprotein-E knockout mice fed a Western diet. These cells exhibited dysregulated expression of genes critically involved in glycolysis and fatty acid degradation, compared with those from animals fed a standard laboratory diet. We examined how T-cell metabolism was changed in either Western diet–fed apolipoprotein-E knockout mice or samples from patients with cardiovascular disease by measuring glucose uptake, activation, and proliferation in CD4 T cells. We found that naive CD4 T cells from Western diet–fed apolipoprotein-E knockout mice failed to uptake glucose and displayed impaired proliferation and activation, compared with CD4 T cells from standard laboratory diet–fed animals. Similarly, we observed that naive CD4 T-cell frequencies were reduced in the circulation of human subjects with high cardiovascular disease compared with low cardiovascular disease. Naive T cells from high cardiovascular disease subjects also showed reduced proliferative capacity.

Conclusions

These results highlight the dysfunction that occurs in CD4 T-cell metabolism and immune responses during atherosclerosis. Targeting metabolic pathways within naive CD4 T cells could thus yield novel therapeutic approaches for improving CD4 T-cell responses against atheroprogression.

T-Cell Molecular Modulation Responses in Atherosclerosis Anergy

Atherosclerosis continues to be a major cause of death in patients with cardiovascular diseases. The cooperative role of immunity has been recently considered in atherosclerotic plaque inflammation, especially adaptive immune response by T cells. In this review, we examine the possible role of T cells in atherosclerosis-mediated inflammation and conceivable therapeutic strategies that can ameliorate complications of atherosclerosis. The cytokines secreted by T-lymphocyte subsets, different pathophysiological profiles of microRNAs (miRs), and the growth factor/receptor axis have diverse effects on the inflammatory cycle of atherosclerosis. Manipulation of miRNA expression and prominent growth factor receptors involved in inflammatory cytokine secretion in atherosclerosis can be considered diagnostic biomarkers in the induction of anergy and blockade of atherosclerotic development. This manuscript reviews immunomodulation of T cells responses in atherosclerosis anergy.

The Immunophenotyping Changes of Peripheral CD4+ T Lymphocytes and Inflammatory Markers of Class III Obesity Subjects After Laparoscopic Gastric Sleeve Surgery - A Follow-Up Study

Purpose

Obesity is a chronic disorder characterized by a low-grade inflammatory state and immune cell irregularities. The study aimed to follow up on the changes in the peripheral CD4+ T lymphocytes and the pro-inflammatory cytokines; IL-6, TNF-alpha, MCP-1, and IL-10 at baseline and 12 weeks post-surgical intervention by the laparoscopic gastric sleeve (LGS) in morbidly obese patients (class III obesity subjects).

Materials and Methods

A prospective longitudinal research included 24 class III obesity subjects with a BMI > 40 kg/m². The subjects were enrolled from the Metabolic/Surgical Department at Hamad Medical Corporation (HMC)-Qatar. Fasting blood samples were collected at admission to LGS for weight loss and after 12 weeks of LGS. The immunophenotype of CD4+ T-cell populations; naïve (CD45RA⁺and CD27⁺), central memory T cells (CD45RO⁺ and CD27⁺), and effector memory (CD45RO⁺and CD27^-) and T-regulatory cell (CD4+CD25+ FoxP3+) were identified using flow cytometry. Plasma pro-inflammatory cytokines and adipokines were evaluated. A control group of lean subjects was used to compare changes of T-regulatory and inflammatory biomarkers with postoperative changes in obese patients.

Results

The means (SD) of age and BMI of class III obesity subjects was 32.32 (8.36) years and 49.02 (6.28) kg/m^2, respectively. LGS caused a significant reduction in BMI by 32%, p<0.0001. LGS intervention significantly decreased CD4+ T-lymphocytes and effector memory (TEM) cells but increased T-regulatory (Treg), naïve, and central memory (TCM) cells, with all p values < 0.05. The increase of Treg cells postoperative is significantly lower compared to lean subjects, p < 0.05. A significant reduction of plasma IL-6, TNF-α, and MCP-1, but IL-10 significantly increased after LGS, with all p<0.05. Adiponectin/leptin ratio improved after LGS by 2.9 folds, p<0.0001.

Conclusion

Weight loss by LGS accomplished a substantial rise of Treg and decreased EM T-lymphocytes with a shift from pro-inflammatory to the anti-inflammatory pattern.

Effect of Lipids and Lipoproteins on Hematopoietic Cell Metabolism and Commitment in Atherosclerosis

Hematopoiesis is the process that leads to multiple leukocyte lineage generation within the bone marrow. This process is maintained throughout life thanks to a nonstochastic division of hematopoietic stem cells (HSCs), where during each division, one daughter cell retains pluripotency while the other differentiates into a restricted multipotent progenitor (MPP) that converts into mature, committed circulating cell. This process is tightly regulated at the level of cellular metabolism and the shift from anaerobic glycolysis, typical of quiescent HSC, to oxidative metabolism fosters HSCs proliferation and commitment. Systemic and local factors influencing metabolism alter HSCs balance under pathological conditions, with chronic metabolic and inflammatory diseases driving HSCs commitment toward activated blood immune cell subsets. This is the case of atherosclerosis, where impaired systemic lipid metabolism affects HSCs epigenetics that reflects into increased differentiation toward activated circulating subsets.

Aim of this review is to discuss the impact of lipids and lipoproteins on HSCs pathophysiology, with a focus on the molecular mechanisms influencing cellular metabolism. A better understanding of these aspects will shed light on innovative strategies to target atherosclerosis-associated inflammation.

Identification of human immune cell subtypes most responsive to IL-1β-induced inflammatory signaling using mass cytometry

IL-1β is a key mediator of the cytokine storm linked to high morbidity and mortality from COVID-19, and IL-1β blockade with anakinra and canakinumab during COVID-19 infection has entered clinical trials. Using mass cytometry of human peripheral blood mononuclear cells, we identified effector memory CD4⁺ T cells and CD4^-CD8^low/-CD161⁺ T cells, specifically those positive for the chemokine receptor CCR6, as the circulating immune subtypes with the greatest response to IL-1β. This response manifested as increased phosphorylation and, thus, activation of the proinflammatory transcription factor NF-κB and was also seen in other subsets, including CD11c⁺ myeloid dendritic cells, classical monocytes, two subsets of natural killer cells (CD16^-CD56^brightCD161^- and CD16^-CD56^dimCD161⁺), and lineage^- (Lin^-) cells expressing CD161 and CD25. IL-1β also induced a rapid but less robust increase in the phosphorylation of the kinase p38 as compared to that of NF-κB in most of these immune cell subsets. Prolonged IL-1β stimulation increased the phosphorylation of the transcription factor STAT3 and to a lesser extent that of STAT1 and STAT5 across various immune cell types. IL-1β-induced production of IL-6 likely led to the activation of STAT1 and STAT3 at later time points. Interindividual heterogeneity and inhibition of STAT activation by anakinra raise the possibility that assays measuring NF-κB phosphorylation in response to IL-1β in CCR6⁺ T cell subtypes could identify those patients at higher risk of cytokine storm and most likely to benefit from IL-1β-neutralizing therapies.

Purinergic Signaling in Controlling Macrophage and T Cell Functions During Atherosclerosis Development

Atherosclerosis is a hardening and narrowing of arteries causing a reduction of blood flow. It is a leading cause of death in industrialized countries as it causes heart attacks, strokes, and peripheral vascular disease. Pathogenesis of the atherosclerotic lesion (atheroma) relies on the accumulation of cholesterol-containing low-density lipoproteins (LDL) and on changes of artery endothelium that becomes adhesive for monocytes and lymphocytes. Immunomediated inflammatory response stimulated by lipoprotein oxidation, cytokine secretion and release of pro-inflammatory mediators, worsens the pathological context by amplifying tissue damage to the arterial lining and increasing flow-limiting stenosis. Formation of thrombi upon rupture of the endothelium and the fibrous cup may also occur, triggering thrombosis often threatening the patient’s life. Purinergic signaling, i.e., cell responses induced by stimulation of P2 and P1 membrane receptors for the extracellular nucleotides (ATP, ADP, UTP, and UDP) and nucleosides (adenosine), has been implicated in modulating the immunological response in atherosclerotic cardiovascular disease. In this review we will describe advancements in the understanding of purinergic modulation of the two main immune cells involved in atherogenesis, i.e., monocytes/macrophages and T lymphocytes, highlighting modulation of pro- and anti-atherosclerotic mediated responses of purinergic signaling in these cells and providing new insights to point out their potential clinical significance.

Adaptive Immune Responses in Human Atherosclerosis

Atherosclerosis is a chronic inflammatory disease that is initiated by the deposition and accumulation of low-density lipoproteins in the artery wall. In this review, we will discuss the role of T- and B-cells in human plaques at different stages of atherosclerosis and the utility of profiling circulating immune cells to monitor atherosclerosis progression. Evidence supports a proatherogenic role for intraplaque T helper type 1 (Th1) cells, CD4⁺CD28^null T-cells, and natural killer T-cells, whereas Th2 cells and regulatory T-cells (Treg) have an atheroprotective role. Several studies indicate that intraplaque T-cells are activated upon recognition of endogenous antigens including heat shock protein 60 and oxidized low-density lipoprotein, but antigens derived from pathogens can also trigger T-cell proliferation and cytokine production. Future studies are needed to assess whether circulating cellular biomarkers can improve identification of vulnerable lesions so that effective intervention can be implemented before clinical manifestations are apparent.

Emergence of T cell immunosenescence in diabetic chronic kidney disease

Background

Type 2 diabetes is an important challenge given the worldwide epidemic and is the most important cause of end-stage renal disease (ESRD) in developed countries. It is known that patients with ESRD and advanced renal failure suffer from immunosenescence and premature T cell aging, but whether such changes develop in patients with less severe chronic kidney disease (CKD) is unclear.

Method

523 adult patients with type 2 diabetes were recruited for this study. Demographic data and clinical information were obtained from medical chart review. Immunosenescence, or aging of the immune system was assessed by staining freshly-obtained peripheral blood with immunophenotyping panels and analyzing cells using multicolor flow cytometry.

Result

Consistent with previously observed in the general population, both T and monocyte immunosenescence in diabetic patients positively correlate with age. When compared to diabetic patients with preserved renal function (estimated glomerular filtration rate > 60 ml/min), patients with impaired renal function exhibit a significant decrease of total CD3⁺ and CD4⁺ T cells, but not CD8⁺ T cell and monocyte numbers. Immunosenescence was observed in patients with CKD stage 3 and in patients with more severe renal failure, especially of CD8⁺ T cells. However, immunosenescence was not associated with level of proteinuria level or glucose control. In age, sex and glucose level-adjusted regression models, stage 3 CKD patients exhibited significantly elevated percentages of CD28^-, CD127^-, and CD57⁺ cells among CD8⁺ T cells when compared to patients with preserved renal function. In contrast, no change was detected in monocyte subpopulations as renal function declined. In addition, higher body mass index (BMI) is associated with enhanced immunosenescence irrespective of CKD status.

Conclusion

The extent of immunosenescence is not significantly associated with proteinuria or glucose control in type 2 diabetic patients. T cells, especially the CD8⁺ subsets, exhibit aggravated characteristics of immunosenescence during renal function decline as early as stage 3 CKD. In addition, inflammation increases since stage 3 CKD and higher BMI drives the accumulation of CD8⁺CD57⁺ T cells. Our study indicates that therapeutic approaches such as weight loss may be used to prevent the emergence of immunosenescence in diabetes before stage 3 CKD.

Naive CD8+ T Cells Expressing CD95 Increase Human Cardiovascular Disease Severity

OBJECTIVE

Cardiovascular disease (CVD) remains a significant global health concern with a high degree of mortality. While CD4⁺ T cells have been extensively studied in CVD, the importance of CD8⁺ T cells in this disease, despite their abundance and increased activation in human atherosclerotic plaques, remains largely unknown. Thus, the objective of this study was to compare peripheral T-cell signatures between humans with a high (severe) risk of CVD (including myocardial infarction or stroke) and those with a low risk of CVD. Approach and Results: Using mass cytometry, we uncovered a naive CD8⁺ T (T_N) cell population expressing CD95 (termed CD95⁺CD8⁺ stem cell memory T [CD8 T_SCM] cells) that was enriched in patients with high compared with low CVD. This T-cell subset enrichment within individuals with high CVD was a relative increase and resulted from the loss of CD95^lo cells within the T_N compartment. We found that CD8 T_SCM cells positively correlated with CVD risk in humans, while CD8⁺ T_N cells were inversely correlated. Atherosclerotic apolipoprotein E-deficient (ApoE^-/-) mice also displayed respective 7- and 2-fold increases in CD8⁺ T_SCM frequencies within the peripheral blood and aorta-draining paraaortic lymph nodes compared with C57BL/6J mice. CD8⁺ T_SCM cells were 1.7-fold increased in aortas from western diet fed ApoE^-/- mice compared with normal laboratory diet-fed ApoE^-/- mice. Importantly, transfer of T_SCM cells into immune-deficient Rag.Ldlr recipient mice that lacked T cells increased atherosclerosis, illustrating the importance of these cells in atherogenesis.

CONCLUSIONS

CD8⁺ T_SCM cells are increased in humans with high CVD. As these T_SCM cells promote atherosclerosis, targeting them may attenuate atherosclerotic plaque progression.

The Role of T Cells Reactive to the Cathelicidin Antimicrobial Peptide LL-37 in Acute Coronary Syndrome and Plaque Calcification

The human cationic anti-microbial peptide LL-37 is a T cell self-antigen in patients with psoriasis, who have increased risk of cardiovascular events. However, the role of LL-37 as a T cell self-antigen in the context of atherosclerosis remains unclear. The objective of this study was to test for the presence of T cells reactive to LL-37 in patients with acute coronary syndrome (ACS). Furthermore, the role of T cells reactive to LL-37 in atherosclerosis was assessed using apoE-/- mice immunized with the LL-37 mouse ortholog, mCRAMP. Peripheral blood mononuclear cells (PBMCs) from patients with ACS were stimulated with LL-37. PBMCs from stable coronary artery disease (CAD) patients or self-reported subjects served as controls. T cell memory responses were analyzed with flow cytometry. Stimulation of PBMCs with LL-37 reduced CD8+ effector T cell responses in controls and patients with stable CAD but not in ACS and was associated with reduced programmed cell death protein 1 (PDCD1) mRNA expression. For the mouse studies, donor apoE-/- mice were immunized with mCRAMP or adjuvant as controls, then T cells were isolated and adoptively transferred into recipient apoE-/- mice fed a Western diet. Recipient mice were euthanized after 5 weeks. Whole aortas and hearts were collected for analysis of atherosclerotic plaques. Spleens were collected for flow cytometric and mRNA expression analysis. Adoptive transfer experiments in apoE-/- mice showed a 28% reduction in aortic plaque area in mCRAMP T cell recipient mice (P < 0.05). Fifty six percent of adjuvant T cell recipient mice showed calcification in atherosclerotic plaques, compared to none in the mCRAMP T cell recipient mice (Fisher's exact test P = 0.003). Recipients of T cells from mice immunized with mCRAMP had increased IL-10 and IFN-γ expression in CD8+ T cells compared to controls. In conclusion, the persistence of CD8+ effector T cell response in PBMCs from patients with ACS stimulated with LL-37 suggests that LL-37-reactive T cells may be involved in the acute event. Furthermore, studies in apoE-/- mice suggest that T cells reactive to mCRAMP are functionally active in atherosclerosis and may be involved in modulating plaque calcification.

Metabolic adaptations of cells at the vascular-immune interface during atherosclerosis

Metabolic reprogramming is a physiological cellular adaptation to intracellular and extracellular stimuli that couples to cell polarization and function in multiple cellular subsets. Pathological conditions associated to nutrients overload, such as dyslipidaemia, may disturb cellular metabolic homeostasis and, in turn, affect cellular response and activation, thus contributing to disease progression. At the vascular/immune interface, the site of atherosclerotic plaque development, many of these changes occur. Here, an intimate interaction between endothelial cells (ECs), vascular smooth muscle cells (VSMCs) and immune cells, mainly monocytes/macrophages and lymphocytes, dictates physiological versus pathological response. Furthermore, atherogenic stimuli trigger metabolic adaptations both at systemic and cellular level that affect the EC layer barrier integrity, VSMC proliferation and migration, monocyte infiltration, macrophage polarization, lymphocyte T and B activation. Rewiring cellular metabolism by repurposing “metabolic drugs” might represent a pharmacological approach to modulate cell activation at the vascular immune interface thus contributing to control the immunometabolic response in the context of cardiovascular diseases.

Antibody-Mediated Inhibition of CTLA4 Aggravates Atherosclerotic Plaque Inflammation and Progression in Hyperlipidemic Mice

T cell-driven inflammation plays a critical role in the initiation and progression of atherosclerosis. The co-inhibitory protein Cytotoxic T-Lymphocyte Associated protein (CTLA) 4 is an important negative regulator of T cell activation. Here, we studied the effects of the antibody-mediated inhibition of CTLA4 on experimental atherosclerosis by treating 6-8-week-old Ldlr-/- mice, fed a 0.15% cholesterol diet for six weeks, biweekly with 200 μg of CTLA4 antibodies or isotype control for six weeks. 18F-fluorodeoxyglucose Positron Emission Tomography-Computed Tomography showed no effect of the CTLA4 inhibition of activity in the aorta, spleen, and bone marrow, indicating that monocyte/macrophage-driven inflammation was unaffected. Correspondingly, flow cytometry demonstrated that the antibody-mediated inhibition of CTLA4 did not affect the monocyte populations in the spleen. αCTLA4 treatment induced an activated T cell profile, characterized by a decrease in naïve CD44-CD62L+CD4+ T cells and an increase in CD44+CD62L- CD4+ and CD8+ T cells in the blood and lymphoid organs. Furthermore, αCTLA4 treatment induced endothelial activation, characterized by increased ICAM1 expression in the aortic endothelium. In the aortic arch, which mainly contained early atherosclerotic lesions at this time point, αCTLA4 treatment induced a 2.0-fold increase in the plaque area. These plaques had a more advanced morphological phenotype and an increased T cell/macrophage ratio, whereas the smooth muscle cell and collagen content decreased. In the aortic root, a site that contained more advanced plaques, αCTLA4 treatment increased the plaque T cell content. The short-term antibody-mediated inhibition of CTLA4 thus accelerated the progression of atherosclerosis by inducing a predominantly T cell-driven inflammation, and resulted in the formation of plaques with larger necrotic cores and less collagen. This indicates that existing therapies that are based on αCTLA4 antibodies may promote CVD development in patients.

T Lymphocyte Subsets Associated With Prevalent Diabetes in Veterans With and Without Human Immunodeficiency Virus

BACKGROUND

A higher proportion of circulating memory CD4+ T cells is associated with prevalent diabetes mellitus in the general population. Given the broad changes in adaptive immunity, including memory T-cell expansion, and rising prevalence of diabetes in the human immunodeficiency virus (HIV) population, we assessed whether similar relationships were present in persons with HIV (PWH).

METHODS

Multiple CD4+ and CD8+ T-cell subsets were measured by flow cytometry, and prevalent diabetes cases were adjudicated by 2 physicians for PWH and HIV-negative participants in the Veterans Aging Cohort Study. Multivariable logistic regression models evaluated the association of T-cell subsets and diabetes stratified by HIV status, adjusted for cytomegalovirus serostatus and traditional risk factors.

RESULTS

Among 2385 participants (65% PWH, 95% male, 68% African American), higher CD45RO+ memory CD4+ T cells and lower CD38+ CD4+ T cells were associated with prevalent diabetes, and had a similar effect size, in both the PWH and HIV-negative (P ≤ .05 for all). Lower CD38+CD8+ T cells were also associated with diabetes in both groups.

CONCLUSIONS

The CD4+ and CD8+ T-cell subsets associated with diabetes are similar in PWH and HIV-negative individuals, suggesting that diabetes in PWH may be related to chronic immune activation.

Allogeneic ADSCs Induce the Production of Alloreactive Memory-CD8 T Cells through HLA-ABC Antigens

We investigated the immunogenicity of allogeneic human adipose-derived mesenchymal stem cells (ADSCs) through the production of alloreactive-CD8 T and -memory CD8 T cells, based on their human leukocyte antigen (HLA) expression. In surface antigen analysis, ADSCs do not express co-stimulatory molecules, but expresses HLA-ABC, which is further increased by exposure to the pro-inflammatory cytokines as well as IFN-γ alone. For immunogenicity analysis, allogeneic ADSCs cultured in xenofree medium (XF-ADSCs) were incubated with the recipient immune cells for allogeneic-antigen stimulation. As a result, XF-ADSCs induced IFN-γ and IL-17A release by alloreactive-CD8 T cells and the production of alloreactive-CD8 T cell through a direct pathway, although they have immunomodulatory activity. In the analysis of alloreactive memory CD8 T cells, XF-ADSCs also significantly induced the production of CFSE-low-CD8 TEM and -CD8 TCM cells. However, HLA-blocking antibodies significantly inhibited the production of CFSE-low memory-CD8 T cells, indicating that HLAs are the main antigens responsible for the development of allogeneic ADSCs' immunogenicity. These results suggested that HLA surface antigens expressed in allogeneic MSCs should be solved in order to address concerns related to the immunogenicity problem.

Sex as a Determinant of Responses to a Coronary Artery Disease Self-Antigen Identified by Immune-Peptidomics

A significant body of work implicates the adaptive immune response in atherosclerosis, the main underlying cause of coronary artery disease (CAD), yet specific antigens involved remain to be fully identified. The pathobiology of CAD is influenced by sex with many factors that may be involved in the underlying mechanisms. Given the reported sexual dimorphic nature of immune-inflammatory responses, we investigated the influence of sex on potential CAD self-antigens from acute coronary syndrome (ACS) patients using immune-precipitation of soluble HLA Class-I/peptide complexes and mass spectrometry. Relevance of identified self-antigens to atherosclerosis, the major underlying cause of CAD, was tested in the apoE–/– atherosclerotic mouse model. Soluble HLA Class-I complexes from ACS patients and self-reported controls were immune-precipitated and subjected to elution, denaturation and size-exclusion to obtain HLA-bound peptides. Peptides were then subjected to mass spectrometry and patient-unique self-peptides were grouped as common to both female and male, or unique to either sex. Three peptides common to both female and male patients (COL6A1, CDSN, and SAA2), and 2 peptides each unique to female (COL1A1 and COL5A2) or male (SAA1 and KRT 9) patients were selected and mouse homologs of the peptides were screened for self-reactive immune responses in apoE–/– mice. The screening step revealed potential sex-influenced immune responses which was associated with differential immune profiles. Based on the frequency in patient plasma, COL6A1, COL5A2, and KRT 9 peptides were then tested in immunization studies. Neither COL5A2 nor KRT 9 peptide immunization resulted in significant effects on atherosclerosis compared to controls. On the other hand, female mice immunized with COL6A1 peptide had significantly reduced atherosclerosis whereas male mice had significantly increased atherosclerosis, associated with differential immune profiles. Our study identified potential self-antigens involved in atherosclerosis using the immune peptidome of CAD patients. Altering self-reactive immune responses to COL6A1 in apoE–/– mice resulted in differential effects on atherosclerosis burden with sex as a determinant of outcome.

Innate and adaptive immune cell subsets as risk factors for coronary heart disease in two population-based cohorts

BACKGROUND AND AIMS

Cell-mediated immunity is implicated in atherosclerosis. We evaluated whether innate and adaptive immune cell subsets in peripheral blood are risk factors for coronary heart disease.

METHODS

A nested case-cohort study (n = 2155) was performed within the Multi-Ethnic Study of Atherosclerosis (MESA) and the Cardiovascular Health Study (CHS). Cases of incident myocardial infarction (MI) and incident angina (n = 880 total cases) were compared with a cohort random sample (n = 1275). Immune cell phenotypes (n = 34, including CD14⁺ monocytes, natural killer cells, γδ T cells, CD4⁺, CD8⁺ and CD19⁺ lymphocyte subsets) were measured from cryopreserved cells by flow cytometry. Cox proportional hazards models with adjustment for cardiovascular disease risk factors were used to evaluate associations of cell phenotypes with incident MI and a composite phenotype of incident MI or incident angina (MI-angina) over a median 9.3 years of follow-up. Th1, Th2, Th17, T regulatory (CD4⁺CD25⁺CD127^-), naive (CD4⁺CD45RA⁺), memory (CD4⁺CD45RO⁺), and CD4⁺CD28^- cells were specified as primary hypotheses. In secondary analyses, 27 additional cell phenotypes were investigated.

RESULTS

After correction for multiple testing, there were no statistically significant associations of CD4⁺ naive, memory, CD28^-, or T helper cell subsets with MI or MI-angina in MESA, CHS, or combined-cohort meta analyses. Null associations were also observed for monocyte subsets, natural killer cells, γδ T cells, CD19⁺ B cell and differentiated CD4⁺ and CD8⁺ cell subsets.

CONCLUSIONS

The proportions of peripheral blood monocyte and lymphocyte subsets are not strongly related to the future occurrence of MI or angina in adults free of autoimmune disease.

Associations of Innate and Adaptive Immune Cell Subsets With Incident Type 2 Diabetes Risk: The MESA Study

OBJECTIVE

Cell-mediated immunity is implicated in glucose homeostasis and insulin resistance. Whether the levels of innate and adaptive immune cells in peripheral blood are risk factors for incident type 2 diabetes (T2D) remains unknown. We hypothesized that the proportions of naive, memory, CD28-, Th17, and T regulatory CD4+ cells would be associated with incident T2D. In secondary analyses, we evaluated the relationships of 28 additional immune cell phenotypes with T2D.

DESIGN

Immune cell phenotypes (n = 33) were measured by flow cytometry using cryopreserved cells collected from 1113 participants of the Multi-Ethnic Study of Atherosclerosis (MESA) at the baseline examination (2000-2002). Cox proportional hazards models were used to evaluate associations of immune cell phenotypes with incident T2D over a median follow-up of 9.1 years, adjusted for age, sex, race/ethnicity, educational status, and body mass index.

RESULTS

Incident T2D was observed for 120 participants. None of the cell phenotypes included in the primary hypotheses were significantly associated with T2D (all P > 0.05). Among the secondary immune cells studied, a higher proportion of CD19+CD27+ B cells was associated with a reduced risk of T2D (hazard ratio: 0.72 (95% confidence interval: 0.56, 0.93), per 1-standard deviation (16%) increase). This association was no longer significant after correction for the multiple cell phenotypes tested (P > 0.0015).

CONCLUSIONS

Our results suggest that the frequencies of several subsets of monocytes, innate lymphocytes, and CD4+ and CD8+ T cells in circulating blood are not related to the future onset of T2D. Higher levels of CD19+CD27+ B cells may be associated with decreased T2D risk.

Low Levels of CD4 + CD28 null T Cells at Baseline Are Associated With First-Time Coronary Events in a Prospective Population-Based Case-Control Cohort

Objective:

CD4 + CD28 null T cells have been shown to be associated with recurrent coronary events and suggested as potential biomarker and therapeutic target. It is unknown whether CD4 + CD28 null T cells associate with first-time cardiovascular events. We examined CD4 + CD28 null T cells in a prospective population-based cohort and in patients with advanced atherosclerosis.

Approach and Results:

CD4 + CD28 null T cells were quantified in 272 individuals experiencing a first-time coronary event during up to 17 years of follow-up and 272 age- and sex-matched controls in a case-control study, nested within the population-based Malmö Diet and Cancer study. The highest tertile of CD4 + CD28 null T cells was associated with a lower incidence of first-time coronary events compared with the lowest tertile (odds ratio, 0.48 [95% CI, 0.29–0.79], P =0.004) when adjusting for Framingham risk factors. This association remained significant for events recorded after >9 years of follow-up, when most coronary events occurred, but not during the first 9 years of follow-up, despite similar odds ratio. Additionally, we analyzed CD4 + CD28 null T cells in 201 patients with advanced atherosclerosis undergoing carotid endarterectomy. The adjusted hazard ratio for cardiovascular events in patients with advanced atherosclerosis was 2.11 (95% CI, 1.10–4.05, P =0.024), comparing the highest with the lowest CD4 + CD28 null T-cell tertile.

Conclusions:

Our findings reveal complex associations between CD4 + CD28 null T cells and cardiovascular disease. Although we confirm the reported positive associations with an adverse prognosis in patients with already established disease, the opposite associations with first-time coronary events in the population-based cohort may limit the clinical use of CD4 + CD28 null T cells.

Contributions of Age-Related Thymic Involution to Immunosenescence and Inflammaging

Immune system aging is characterized by the paradox of immunosenescence (insufficiency) and inflammaging (over-reaction), which incorporate two sides of the same coin, resulting in immune disorder. Immunosenescence refers to disruption in the structural architecture of immune organs and dysfunction in immune responses, resulting from both aged innate and adaptive immunity. Inflammaging, described as a chronic, sterile, systemic inflammatory condition associated with advanced age, is mainly attributed to somatic cellular senescence-associated secretory phenotype (SASP) and age-related autoimmune predisposition. However, the inability to reduce senescent somatic cells (SSCs), because of immunosenescence, exacerbates inflammaging. Age-related adaptive immune system deviations, particularly altered T cell function, are derived from age-related thymic atrophy or involution, a hallmark of thymic aging. Recently, there have been major developments in understanding how age-related thymic involution contributes to inflammaging and immunosenescence at the cellular and molecular levels, including genetic and epigenetic regulation, as well as developments of many potential rejuvenation strategies. Herein, we discuss the research progress uncovering how age-related thymic involution contributes to immunosenescence and inflammaging, as well as their intersection. We also describe how T cell adaptive immunity mediates inflammaging and plays a crucial role in the progression of age-related neurological and cardiovascular diseases, as well as cancer. We then briefly outline the underlying cellular and molecular mechanisms of age-related thymic involution, and finally summarize potential rejuvenation strategies to restore aged thymic function.

Productive Cytomegalovirus Infection Is Associated With Impaired Endothelial Function in ST-Elevation Myocardial Infarction

BACKGROUND

An association between productive cytomegalovirus infection and atherosclerosis was shown recently in several trials, including a previous study of ours. However, the mechanism involved in this association is still under investigation. Here, we addressed the interaction between productive cytomegalovirus infection and endothelial function in patients with ST-elevation myocardial infarction (STEMI).

METHODS

We analyzed the presence of cytomegaloviral DNA in plasma and endothelial function in 33 patients with STEMI and 33 volunteers without cardiovascular diseases, using real-time polymerase chain reaction (PCR) and a noninvasive test of flow-mediated dilation.

RESULTS

Both the frequency of presence and the load of cytomegaloviral DNA were higher in plasma of patients with STEMI than those in controls. This difference was independent of other cardiovascular risk factors (7.38 [1.36-40.07]; P = 0.02). The results of the flow-mediated dilation test were lower in patients in STEMI than in controls (5.0% [2.65%-3.09%] vs 12. %5 [7.5%-15.15%]; P = 0.004) and correlated negatively with the cytomegaloviral DNA load (Spearman R = -0.407; P = 0.019) independently of other cardiovascular risk factors.

CONCLUSIONS

Productive cytomegalovirus infection in patients with STEMI correlated negatively with endothelial function independently of other cardiovascular risk factors. The impact of cytomegalovirus on endothelial function may explain the role of cytomegalovirus in cardiovascular prognosis.

Short-Chain Fatty Acid Propionate Protects From Hypertensive Cardiovascular Damage

Supplemental Digital Content is available in the text.

Background:

Arterial hypertension and its organ sequelae show characteristics of T cell–mediated inflammatory diseases. Experimental anti-inflammatory therapies have been shown to ameliorate hypertensive end-organ damage. Recently, the CANTOS study (Canakinumab Antiinflammatory Thrombosis Outcome Study) targeting interleukin-1β demonstrated that anti-inflammatory therapy reduces cardiovascular risk. The gut microbiome plays a pivotal role in immune homeostasis and cardiovascular health. Short-chain fatty acids (SCFAs) are produced from dietary fiber by gut bacteria and affect host immune homeostasis. Here, we investigated effects of the SCFA propionate in 2 different mouse models of hypertensive cardiovascular damage.

Methods:

To investigate the effect of SCFAs on hypertensive cardiac damage and atherosclerosis, wild-type NMRI or apolipoprotein E knockout–deficient mice received propionate (200 mmol/L) or control in the drinking water. To induce hypertension, wild-type NMRI mice were infused with angiotensin II (1.44 mg·kg^–1·d^–1 subcutaneous) for 14 days. To accelerate the development of atherosclerosis, apolipoprotein E knockout mice were infused with angiotensin II (0.72 mg·kg^–1·d^–1 subcutaneous) for 28 days. Cardiac damage and atherosclerosis were assessed using histology, echocardiography, in vivo electrophysiology, immunofluorescence, and flow cytometry. Blood pressure was measured by radiotelemetry. Regulatory T cell depletion using PC61 antibody was used to examine the mode of action of propionate.

Results:

Propionate significantly attenuated cardiac hypertrophy, fibrosis, vascular dysfunction, and hypertension in both models. Susceptibility to cardiac ventricular arrhythmias was significantly reduced in propionate-treated angiotensin II–infused wild-type NMRI mice. Aortic atherosclerotic lesion area was significantly decreased in propionate-treated apolipoprotein E knockout–deficient mice. Systemic inflammation was mitigated by propionate treatment, quantified as a reduction in splenic effector memory T cell frequencies and splenic T helper 17 cells in both models, and a decrease in local cardiac immune cell infiltration in wild-type NMRI mice. Cardioprotective effects of propionate were abrogated in regulatory T cell–depleted angiotensin II–infused mice, suggesting the effect is regulatory T cell–dependent.

Conclusions:

Our data emphasize an immune-modulatory role of SCFAs and their importance for cardiovascular health. The data suggest that lifestyle modifications leading to augmented SCFA production could be a beneficial nonpharmacological preventive strategy for patients with hypertensive cardiovascular disease.

Shexiang Tongxin Dropping Pill Improves Peripheral Microvascular Blood Flow via Cystathionine-γ-Lyase

Background

To explore the protective effects of Shexiang Tongxin Dropping Pill (STP) in improving peripheral microvascular dysfunction in mice and to explore the involved mechanism.

Material/Methods

A peripheral microvascular dysfunction model was established by combined myocardial infarction (MI) and lipopolysaccharide (LPS) injection in mice. Then, the mice were randomized into a model group (n=10) or an STP group (n=10), which were treated with normal saline and STP, respectively. The cremaster muscle microvascular blood flow velocity and numbers of leukocytes adherent to the venular wall were evaluated before and after drug intervention. We assessed the expression of adhesion molecule CD11b and related transcript factor FOXO1 in leukocytes, cystathionine-γ-lyase (CSE) mRNA expression in the cremaster muscle, and mitochondrial DNA copy numbers.

Results

Compared with those of control mice, the cremaster microvascular blood flow velocity, cremaster CSE expression, and mitochondrial DNA copy number in mice from the model group were significantly lower and leukocyte adhesion and CD11b and FOXO1 expression were significantly higher. Intervention with STP could significantly increase the cremaster microvascular flow velocity (0.480±0.010 mm/s vs. 0.075±0.005 mm/s), mRNA expression of cremaster CSE, and mitochondrial DNA copy number, but it inhibited leukocyte adhesion and decreased leukocyte CD11b and FOXO1 expression.

Conclusions

STP significantly improved peripheral microcirculation, in which increased CSE expression might be the underlying mechanism.

T-cell aging in end-stage renal disease: an evolving story with CMV

Established evidence from the last decade has suggested that chronic cytomegalovirus infection has strong impact on the human immune system, resulting in aggravated aging-associated T-cell changes that are associated with poorer vaccination responses, cardiovascular disease and shortened survival. Patients with end-stage renal disease (ESRD), the most severe form of chronic kidney disease, exhibit premature aging phenotypes in almost all organ systems, including the immune system. Longitudinal studies of T-cell aging in healthy humans have been scanty because it requires a large number of study subjects and a study duration for decades. In recent years, it became clear that ESRD patients with cytomegalovirus (CMV) infection exhibit enhanced aging-related immune changes than CMV-seropositive individuals without renal disease, including chronic inflammation, decreased numbers of naïve CD4+ and CD8+ T cells, increased clonality of memory T cells with skewed repertoire and shortened telomeres. These findings lead to the hypothesis that the uremic milieu and treatment for renal failure can lead to premature aging of T cells independent from CMV infection and suggest that ESRD can be an important disease model for studying human aging. Future studies deciphering the underlying mechanisms of accelerated T cell aging in ESRD patients may eventually reveal additional insights into T-cell persistence and function during aging in CMV-seropositive, non-ESRD individuals.

Keratin 8 is a potential self-antigen in the coronary artery disease immunopeptidome: A translational approach

Background

Inflammation is an important risk factor in atherosclerosis, the underlying cause of coronary artery disease (CAD). Unresolved inflammation may result in maladaptive immune responses and lead to immune reactivity to self-antigens. We hypothesized that inflammation in CAD patients would manifest in immune reactivity to self-antigens detectable in soluble HLA-I/peptide complexes in the plasma.

Methods

Soluble HLA-I/peptide complexes were immuno-precipitated from plasma of male acute coronary syndrome (ACS) patients or age-matched controls and eluted peptides were subjected to mass spectrometry to generate the immunopeptidome. Self-peptides were ranked according to frequency and signal intensity, then mouse homologs of selected peptides were used to test immunologic recall in spleens of male apoE-/- mice fed either normal chow or high fat diet. The peptide detected with highest frequency in patient plasma samples and provoked T cell responses in mouse studies was selected for use as a self-antigen to stimulate CAD patient peripheral blood mononuclear cells (PBMCs).

Results

The immunopeptidome profile identified self-peptides unique to the CAD patients. The mouse homologs tested showed immune responses in apoE-/- mice. Keratin 8 was selected for further study in patient PBMCs which elicited T Effector cell responses in CAD patients compared to controls, associated with reduced PD-1 mRNA expression.

Conclusion

An immunopeptidomic strategy to search for self-antigens potentially involved in CAD identified Keratin 8. Self-reactive immune response to Keratin 8 may be an important factor in the inflammatory response in CAD.

A comprehensive characterization of aggravated aging-related changes in T lymphocytes and monocytes in end-stage renal disease: the iESRD study

Background

Patients with end-stage renal disease (ESRD) exhibit a premature aging phenotype of the immune system. Nevertheless, the etiology and impact of these changes in ESRD patients remain unknown.

Results

Compared to healthy individuals, ESRD patients exhibit accelerated immunosenescence in both T cell and monocyte compartments, characterized by a dramatic reduction in naïve CD4+ and CD8+ T cell numbers but increase in CD8+ T_EMRA cell and proinflammatory monocyte numbers. Notably, within ESRD patients, aging-related immune changes positively correlated not only with increasing age but also with longer dialysis vintage. In multivariable-adjusted logistic regression models, the combination of high terminally differentiated CD8+ T cell level and high intermediate monocyte level, as a composite predictive immunophenotype, was independently associated with prevalent coronary artery disease as well as cardiovascular disease, after adjustment for age, sex, systemic inflammation and presence of diabetes. Levels of terminally differentiated CD8+ T cells also positively correlated with the level of uremic toxin p-cresyl sulfate.

Conclusions

Aging-associated adaptive and innate immune changes are aggravated in ESRD and are associated with cardiovascular diseases. For the first time, our study demonstrates the potential link between immunosenescence in ESRD and duration of exposure to the uremic milieu.

Electronic supplementary material

The online version of this article (10.1186/s12979-018-0131-x) contains supplementary material, which is available to authorized users.

Interferon-α-Mediated Activation of T Cells from Healthy and HIV-Infected Individuals Is Suppressed by Δ9-Tetrahydrocannabinol

Patients with HIV routinely use medicinal cannabinoids to treat neuropathic pain, anxiety, and human immunodeficiency virus (HIV)-associated wasting. However, Δ9-tetrahydrocannabinol (THC), the primary psychoactive cannabinoid in cannabis, suppresses T-cell function and secretion of interferons, both critically important in the antiviral immune response. Interferon-α (IFNα), a key cytokine in T-cell activation and peripheral control of HIV infection, can potentiate responsiveness to interleukin-7 (IL-7), a crucial homeostatic cytokine for peripheral T-cell maintenance. The objective of this investigation was to compare the response of T cells to stimulation by IFNα and IL-7 in T cells from healthy and HIV+ donors in the absence and presence of THC. To compare T-cell responses between healthy and HIV+ donors signaling through IFNα receptor, IFNα-induced expression of IL-7α receptor (IL-7Rα), cognate signaling through IL-7R, and on IL-7-mediated T-cell proliferation were measured by flow cytometry and real-time quantitative polymerase chain reaction. CD8+ T cells from HIV+ donors showed a diminished response to IFNα-induced phosphorylated signal transducer and activator of transcription-1 activation compared with CD8+ T cells from healthy donors, whereas CD4+ T cells from HIV+ donors and healthy donors were comparable. Treatment with IFNα promoted IL-7R expression and potentiated IL-7-induced STAT5 phosphorylation to augment IL-7-mediated proliferation by T cells from healthy and HIV+ donors. Finally, HIV+ donors exhibited reduced sensitivity to THC-mediated suppression by IFNα- and IL-7-mediated stimulation compared with healthy donors. These results further support THC as being immune suppressive while identifying putatively beneficial aspects of cannabinoid-based therapies in HIV+ patients.

Myeloid apolipoprotein E controls dendritic cell antigen presentation and T cell activation

Cholesterol homeostasis has a pivotal function in regulating immune cells. Here we show that apolipoprotein E (apoE) deficiency leads to the accumulation of cholesterol in the cell membrane of dendritic cells (DC), resulting in enhanced MHC-II-dependent antigen presentation and CD4⁺ T-cell activation. Results from WT and apoE KO bone marrow chimera suggest that apoE from cells of hematopoietic origin has immunomodulatory functions, regardless of the onset of hypercholesterolemia. Humans expressing apoE4 isoform (ε4/3–ε4/4) have increased circulating levels of activated T cells compared to those expressing WT apoE3 (ε3/3) or apoE2 isoform (ε2/3–ε2/2). This increase is caused by enhanced antigen-presentation by apoE4-expressing DCs, and is reversed when these DCs are incubated with serum containing WT apoE3. In summary, our study identifies myeloid-produced apoE as a key physiological modulator of DC antigen presentation function, paving the way for further explorations of apoE as a tool to improve the management of immune diseases.

Cholesterol homeostasis can modulate immunity via multiple pathways. Here the authors show that apolipoprotein E, an important regulator of cholesterol, produced by myeloid cells can regulate T cell activation by controlling the antigen presentation activity of dendritic cells in both humans and mice.

Immune cell subset differentiation and tissue inflammation

Immune cells were traditionally considered as major pro-inflammatory contributors. Recent advances in molecular immunology prove that immune cell lineages are composed of different subsets capable of a vast array of specialized functions. These immune cell subsets share distinct duties in regulating innate and adaptive immune functions and contribute to both immune activation and immune suppression responses in peripheral tissue. Here, we summarized current understanding of the different subsets of major immune cells, including T cells, B cells, dendritic cells, monocytes, and macrophages. We highlighted molecular characterization, frequency, and tissue distribution of these immune cell subsets in human and mice. In addition, we described specific cytokine production, molecular signaling, biological functions, and tissue population changes of these immune cell subsets in both cardiovascular diseases and cancers. Finally, we presented a working model of the differentiation of inflammatory mononuclear cells, their interaction with endothelial cells, and their contribution to tissue inflammation. In summary, this review offers an updated and comprehensive guideline for immune cell development and subset differentiation, including subset characterization, signaling, modulation, and disease associations. We propose that immune cell subset differentiation and its complex interaction within the internal biological milieu compose a “pathophysiological network,” an interactive cross-talking complex, which plays a critical role in the development of inflammatory diseases and cancers.

HIV and Cardiovascular Disease: Role of Immunometabolic Perturbations

The successful rollout of anti-retroviral therapy ensured that HIV is increasingly managed as a chronic condition. HIV-positive persons are therefore exhibiting increased cardiovascular complications. This review focuses on the emerging role of "immunometabolism" within the context of HIV-related immune dysregulation and cardiovascular disease onset. Here, persistent immune activation contributes to pathophysiological perturbations during early infection, resulting in immune cell metabolic reprogramming and the activation of coagulation pathways in HIV-positive individuals.

Epigenetics and Immunometabolism in Diabetes and Aging

SIGNIFICANCE

A strong relationship between hyperglycemia, impaired insulin pathway, and cardiovascular disease in type 2 diabetes (T2D) is linked to oxidative stress and inflammation. Immunometabolic pathways link these pathogenic processes and pose important potential therapeutic targets. Recent Advances: The link between immunity and metabolism is bidirectional and includes the role of inflammation in the pathogenesis of metabolic disorders such as T2D, obesity, metabolic syndrome, and hypertension and the role of metabolic factors in regulation of immune cell functions. Low-grade inflammation, oxidative stress, balance between superoxide and nitric oxide, and the infiltration of macrophages, T cells, and B cells in insulin-sensitive tissues lead to metabolic impairment and accelerated aging.

CRITICAL ISSUES

Inflammatory infiltrate and altered immune cell phenotype precede development of metabolic disorders. Inflammatory changes are tightly linked to alterations in metabolic status and energy expenditure and are controlled by epigenetic mechanisms.

FUTURE DIRECTIONS

A better comprehension of these mechanistic insights is of utmost importance to identify novel molecular targets. In this study, we describe a complex scenario of epigenetic changes and immunometabolism linking to diabetes and aging-associated vascular disease. Antioxid. Redox Signal. 29, 257-274.

Anti-cytomegalovirus IgG antibody titer is positively associated with advanced T cell differentiation and coronary artery disease in end-stage renal disease

Background

Accumulating evidence indicates that persistent human cytomegalovirus (HCMV) infection is associated with several health-related adverse outcomes including atherosclerosis and premature mortality in individuals with normal renal function. Patients with end-stage renal disease (ESRD) exhibit impaired immune function and thus may face higher risk of HCMV-related adverse outcomes. Whether the level of anti-HCMV immune response may be associated with the prognosis of hemodialysis patients is unknown.

Results

Among 412 of the immunity in ESRD study (iESRD study) participants, 408 were HCMV seropositive and were analyzed. Compared to 57 healthy individuals, ESRD patients had higher levels of anti-HCMV IgG. In a multivariate-adjusted logistic regression model, the log level of anti-HCMV IgG was independently associated with prevalent coronary artery disease (OR = 1.93, 95% CI = 1.2~ 3.2, p = 0.01) after adjusting for age, sex, hemoglobin, diabetes, calcium phosphate product and high sensitivity C-reactive protein. Levels of anti-HCMV IgG also positively correlated with both the percentage and absolute number of terminally differentiated CD8+ and CD4+ CD45RA+ CCR7- T_EMRA cells, indicating that immunosenescence may participate in the development of coronary artery disease.

Conclusion

This is the first study showing that the magnitude of anti-HCMV humoral immune response positively correlates with T cell immunosenescence and coronary artery disease in ESRD patients. The impact of persistent HCMV infection should be further investigated in this special patient population.

Electronic supplementary material

The online version of this article (10.1186/s12979-018-0120-0) contains supplementary material, which is available to authorized users.

Decreased circulating T regulatory lymphocytes in obese patients undergoing bariatric surgery

OBJECTIVE

It has been previously demonstrated that T lymphocytes may be involved in the development of hypertension and microvascular remodeling, and that circulating T effector lymphocytes may be increased in hypertension. In particular, Th1 and Th 17 lymphocytes may contribute to the progression of hypertension and microvascular damage while T-regulatory (Treg) lymphocytes seem to be protective in this regard. However, no data is available about patients with severe obesity, in which pronounced microvascular alterations were observed.

DESIGN AND METHODS

We have investigated 32 severely obese patients undergoing bariatric surgery, as well as 24 normotensive lean subjects and 12 hypertensive lean subjects undergoing an elective surgical intervention. A peripheral blood sample was obtained before surgery for assessment of CD4+ T lymphocyte subpopulations. Lymphocyte phenotype was evaluated by flow cytometry in order to assess T-effector and Treg lymphocytes.

RESULTS

A marked reduction of several Treg subpopulations was observed in obese patients compared with controls, together with an increased in CD4+ effector memory T-effector cells.

CONCLUSION

In severely obese patients, Treg lymphocytes are clearly reduced and CD4+ effector memory cells are increased. It may be hypothesized that they might contribute to the development of marked microvascular alterations previously observed in these patients.

Hypercholesterolemia induces T cell expansion in humanized immune mice

Emerging data suggest that hypercholesterolemia has stimulatory effects on adaptive immunity and that these effects can promote atherosclerosis and perhaps other inflammatory diseases. However, research in this area has relied primarily on inbred strains of mice whose adaptive immune system can differ substantially from that of humans. Moreover, the genetically induced hypercholesterolemia in these models typically results in plasma cholesterol levels that are much higher than those in most humans. To overcome these obstacles, we studied human immune system-reconstituted mice (hu-mice) rendered hypercholesterolemic by treatment with adeno-associated virus 8-proprotein convertase subtilisin/kexin type 9 (AAV8-PCSK9) and a high-fat/high-cholesterol Western-type diet (WD). These mice had a high percentage of human T cells and moderate hypercholesterolemia. Compared with hu-mice that had lower plasma cholesterol, the PCSK9-WD mice developed a T cell-mediated inflammatory response in the lung and liver. Human CD4+ and CD8+ T cells bearing an effector memory phenotype were significantly elevated in the blood, spleen, and lungs of PCSK9-WD hu-mice, whereas splenic and circulating regulatory T cells were reduced. These data show that moderately high plasma cholesterol can disrupt human T cell homeostasis in vivo. This process may not only exacerbate atherosclerosis, but also contribute to T cell-mediated inflammatory diseases in the hypercholesterolemia setting.

Mycobacterium tuberculosis protein Rv2220 induces maturation and activation of dendritic cells

Tuberculosis remains a serious health problem worldwide. Characterization of the dendritic cell (DC)-activating mycobacterial proteins has driven the development of effective TB vaccine candidates besides improving the understanding of immune responses. Some studies have emphasized the essential role of protein Rv2220 from M. tuberculosis in mycobacterial growth. Nonetheless, little is known about cellular immune responses to Rv2220. In this study, our aim was to test whether protein Rv2220 induces maturation and activation of DCs. Rv2220-activated DCs appeared to be in a mature state with elevated expression of relevant surface molecules and proinflammatory cytokines. DC maturation caused by Rv2220 was mediated by MAPK and NF-κB signaling pathways. Specifically, Rv2220-matured DCs induced the expansion of memory CD62L^lowCD44^highCD4⁺ T cells in the spleen of mycobacteria-infected mice. Our results suggest that Rv2220 regulates host immune responses through maturation of DCs, a finding that points to a new vaccine candidate against tuberculosis.

Disease trends over time and CD4+CCR5+ T-cells expansion predict carotid atherosclerosis development in patients with systemic lupus erythematosus

BACKGROUND AND AIM

Patients with Systemic Lupus Erythematosus (SLE) present increased cardiovascular mortality compared to the general population. Few studies have assessed the long-term development and progression of carotid atherosclerotic plaque in SLE patients. Our aim was to investigate the association of clinical and laboratory markers of disease activity and classical cardiovascular risk factors (CVRF) with carotid atherosclerosis development in SLE patients in a prospective 5-year study.

METHODS AND RESULTS

Clinical history and information on principal CVRFs were collected at baseline and after 5 years in 40 SLE patients (36 women, mean age 42 ± 9 years; 14.4 ± 7 years of mean disease duration) and 50 age-matched controls. Carotid Doppler ultrasonography was employed to quantify the atherosclerotic burden at baseline and at follow up. Clinimetrics were applied to assess SLE activity over time (SLEDAI). The association between basal circulating T cell subsets (including CD4⁺CCR5⁺; CD4⁺CXCR3⁺; CD4⁺HLADR⁺; CD4⁺CD45RA⁺RO^-, CD4⁺CD45RO⁺RA^- and their subsets) and atherosclerosis development was evaluated. During the 5-year follow up, 32% of SLE patients, developed carotid atherosclerosis compared to 4% of controls. Furthermore, considering SLEDAI changes over time, patients within the highest tertile were those with increased incidence of carotid atherosclerosis independently of CVRF. In addition, increased levels of CD4⁺CCR5⁺ T cells were independently associated with the development of carotid atherosclerosis in SLE patients.

CONCLUSION

Serial clinical evaluations over time, rather than a single point estimation of disease activity or CVRF burden, are required to define the risk of carotid atherosclerosis development in SLE patients. Specific T cell subsets are associated with long-term atherosclerotic progression and may further be of help in predicting vascular disease progression.

QiShenYiQi pill attenuates atherosclerosis by promoting regulatory T cells, inhibiting T helper 17 cells and accelerating cholesterol excretion

OBJECTIVE

The aim of this study was to explore potential immunoregulatory mechanisms underlying the suppressive effect on atherosclerosis of QiShenYiQi pill (QSYQ).

METHODS AND RESULTS

Male ApoE-/- mice were maintained on a Western-type diet and QSYQ treatment for eight weeks. Determination of atherosclerosis demonstrated that QSYQ attenuated plaque formation and decreased the level of blood low-density lipoproteins-cholesterol. QSYQ treatment did not affect body weight but reduced the ratio of liver weight and body weight. Western blots of liver showed that QSYQ increased the expression of liver X receptor alpha and ATP-binding cassette sub-family G member 5. Western blots of atherosclerotic aorta revealed that QSYQ inhibited the expression of cluster of differentiation 36, promoted the expression of forkhead box P3 and decreased interleukin-17A expression. Western blots of spleen showed that QSYQ decreased the expression of mothers against decapentaplegic homolog 2/3 and forkhead box P3, as well as attenuated the expression of spleen interleukin-6, RAR-related orphan receptor gamma and interleukin-17A.

CONCLUSIONS

QSYQ exerted an anti-atherosclerosis effect by promoting regulatory T cells in atherosclerotic lesion, inhibiting T helper 17 cells in plaque and spleen and accelerating liver cholesterol excretion.