Neopterin, CD4+CD28− lymphocytes and the extent and severity of coronary artery disease

CD28null T cells in aging and diseases: From biology to assessment and intervention

CD28null T cells, an atypical subset characterized by the loss of CD28 costimulatory molecule expression, exhibit functional variants and progressively expand with age. Moreover, T cells with these phenotypes are found in both typical and atypical humoral immune responses. Consequently, they accumulate during infectious diseases, autoimmune disorders, cardiovascular conditions, and neurodegenerative ailments. To provide an in-depth review of the current knowledge regarding CD28null T cells, we specifically focus on their phenotypic and functional characteristics as well as their physiological roles in aging and diseases. While uncertainties regarding the clinical utility remains, we will review the following two crucial research perspectives to explore clinical translational applications of the research on this specific T cell subset: 1) addressing the potential utility of CD28null T cells as immunological markers for prognosis and adverse outcomes in both aging and disease, and 2) speculating on the potential of targeting CD28null T cells as an interventional strategy for preventing or delaying immune aging processes and disease progression.

T cell markers recount the course of immunosenescence in healthy individuals and chronic kidney disease

Aging results in substantial changes in almost all cellular subpopulations within the immune system, including functional and phenotypic alterations. T lymphocytes, as the main representative population of cellular immunity, have been extensively studied in terms of modifications and adjustments during aging. Phenotypic alterations are attributed to three main mechanisms; a reduction of naïve T cell population with a shift to more differentiated forms, a subsequent oligoclonal expansion of naïve T cells characterized by repertoire restriction, and replicative insufficiency after repetitive activation. These changes and the subsequent phenotypic disorders are comprised in the term "immunosenescence". Similar changes seem to occur in chronic kidney disease, with T cells of young patients resembling those of healthy older individuals. A broad range of surface markers can be utilized to identify immunosenescent T cells. In this review, we will discuss the most important senescence markers and their potential connection with impaired renal function.

Accelerated immunosenescence in rheumatoid arthritis: impact on clinical progression

Patients with rheumatoid arthritis (RA) develop features of accelerated ageing, including immunosenescence. These changes include decreased thymic functionality, expansion of late-differentiated effector T cells, increased telomeric attrition, and excessive production of cytokines (senescence-associated secretory phenotype). The progression of RA has been associated with the early development of age-related co-morbidities, including osteoporosis, cardiovascular complications, and cognitive impairment. Here I review data supporting the hypothesis that immune-senescence contributes to the aggravation of both articular and extra-articular manifestations. Of note, poor cognitive functions in RA were associated with senescent CD28- T cells, inflammaging, and autoantibodies against brain antigens. The pathways of immune-to-brain communication are discussed and provide the rationale for the cognitive impairment reported in RA.

NK Cells Contribute to the Immune Risk Profile in Kidney Transplant Candidates

Background: A previously proposed immune risk profile (IRP), based on T cell phenotype and CMV serotype, is associated with mortality in the elderly and increased infections post-kidney transplant. To evaluate if NK cells contribute to the IRP and if the IRP can be predicted by a clinical T cell functional assays, we conducted a cross sectional study in renal transplant candidates to determine the incidence of IRP and its association with specific NK cell characteristics and ImmuKnow® value.

Material and Methods: Sixty five subjects were enrolled in 5 cohorts designated by age and dialysis status. We determined T and NK cell phenotypes by flow cytometry and analyzed multiple factors contributing to IRP.

Results: We identified 14 IRP+ [CMV seropositivity and CD4/CD8 ratio < 1 or being in the highest quintile of CD8+ senescent (28CD–/CD57+) T cells] individuals equally divided amongst the cohorts. Multivariable linear regression revealed a distinct IRP+ group. Age and dialysis status did not predict immune senescence in kidney transplant candidates. NK cell features alone could discriminate IRP– and IRP+ patients, suggesting that NK cells significantly contribute to the overall immune status in kidney transplant candidates and that a combined T and NK cell phenotyping can provide a more detailed IRP definition. ImmuKnow® value was negatively correlated to age and significantly lower in IRP+ patients and predicts IRP when used alone or in combination with NK cell features.

Conclusion: NK cells contribute to overall immune senescence in kidney transplant candidates.

Inflammation Is Strongly Associated With Cardiorespiratory Fitness, Sex, BMI, and the Metabolic Syndrome in a Self-reported Healthy Population: HUNT3 Fitness Study

OBJECTIVE

To investigate whether C-reactive protein (CRP, a general marker of inflammation), neopterin (activated macrophages), lactoferrin (activated neutrophils), and endothelial function (flow-mediated vasodilation [FMD]) are associated with cardiorespiratory fitness (peak oxygen uptake [VO_2peak]), sex, body mass index (BMI), and the metabolic syndrome (MetSyn) in a healthy adult population.

PATIENTS AND METHODS

This was a cross-sectional association study based on the population-based HUNT3 Fitness Study performed from May 15, 2007, through June 23, 2008. Seven hundred forty self-reported healthy respondents (327 women) identified as having the MetSyn were age- and sex-matched with 692 controls (307 women) from the same cohort. Associations between the inflammatory biomarkers and VO_2peak, FMD, and the MetSyn were analyzed by multivariate linear regression.

RESULTS

The CRP level was negatively associated with VO_2peak (P<.001), positively associated with the MetSyn (with a stronger effect in men) (P<.001) and BMI (with a stronger effect in women) (P<.01), but not with FMD (P=.34). Lactoferrin was positively associated with the MetSyn (P<.001), but neither neopterin nor lactoferrin were associated with VO_2peak or FMD.

CONCLUSION

The CRP level was strongly associated with VO_2peak and the MetSyn, but not with FMD. The associations among inflammation, VO_2peak, and the MetSyn were strongly influenced by sex and BMI. These data support that low cardiorespiratory fitness should be considered an etiologic factor contributing to systemic inflammation and that reducing body weight and improving VO_2peak are methods that may positively affect CRP levels.

T-cell senescence contributes to abnormal glucose homeostasis in humans and mice

Chronic inflammation is a driving force for the development of metabolic disease including diabetes and obesity. However, the functional characteristics of T-cell senescence in the abnormal glucose homeostasis are not fully understood. We studied the patients visiting a hospital for routine health check-ups, who were divided into two groups: normal controls and people with prediabetes. Gene expression profiling of peripheral blood mononuclear cells from normal controls and patients with type 2 diabetes was undertaken using microarray analysis. We also investigated the immunometabolic characteristics of peripheral and hepatic senescent T cells in the normal subjects and patients with prediabetes. Moreover, murine senescent T cells were tested functionally in the liver of normal or mice with metabolic deterioration caused by diet-induced obesity. Human senescent (CD28^-CD57⁺) CD8⁺ T cells are increased in the development of diabetes and proinflammatory cytokines and cytotoxic molecules are highly expressed in senescent T cells from patients with prediabetes. Moreover, we demonstrate that patients with prediabetes have higher concentrations of reactive oxygen species (ROS) in their senescent CD8⁺ T cells via enhancing capacity to use glycolysis. These functional properties of senescent CD8⁺ T cells contribute to the impairment of hepatic insulin sensitivity in humans. Furthermore, we found an increase of hepatic senescent T cells in mouse models of aging and diet-induced obesity. Adoptive transfer of senescent CD8⁺ T cells also led to a significant deterioration in systemic abnormal glucose homeostasis, which is improved by ROS scavengers in mice. This study defines a new clinically relevant concept of T-cell senescence-mediated inflammatory responses in the pathophysiology of abnormal glucose homeostasis. We also found that T-cell senescence is associated with systemic inflammation and alters hepatic glucose homeostasis. The rational modulation of T-cell senescence would be a promising avenue for the treatment or prevention of diabetes.

CD28null pro-atherogenic CD4 T-cells explain the link between CMV infection and an increased risk of cardiovascular death

An increased risk of cardiovascular death in Cytomegalovirus (CMV)-infected individuals remains unexplained, although it might partly result from the fact that CMV infection is closely associated with the accumulation of CD28^null T-cells, in particular CD28^null CD4 T-cells. These cells can directly damage endothelium and precipitate cardiovascular events. However, the current paradigm holds that the accumulation of CD28^null T-cells is a normal consequence of aging, whereas the link between these T-cell populations and CMV infection is explained by the increased prevalence of this infection in older people. Resolving whether CMV infection or aging triggers CD28^null T-cell expansions is of critical importance because, unlike aging, CMV infection can be treated.

Methods: We used multi-color flow-cytometry, antigen-specific activation assays, and HLA-typing to dissect the contributions of CMV infection and aging to the accumulation of CD28^null CD4 and CD8 T-cells in CMV+ and CMV- individuals aged 19 to 94 years. Linear/logistic regression was used to test the effect of sex, age, CMV infection, and HLA-type on CD28^null T-cell frequencies.

Results: The median frequencies of CD28^null CD4 T-cells and CD28^null CD8 T-cells were >12-fold (p=0.000) but only approximately 2-fold higher (p=0.000), respectively, in CMV+ (n=136) compared with CMV- individuals (n=106). The effect of CMV infection on these T-cell subsets was confirmed by linear regression. Unexpectedly, aging contributed only marginally to an increase in CD28^null T-cell frequencies, and only in CMV+ individuals. Interestingly, the presence of HLA-DRB1*0301 led to an approximately 9-fold reduction of the risk of having CD28^null CD4 T-cell expansions (OR=0.108, p=0.003). Over 75% of CMV-reactive CD4 T-cells were CD28^null.

Conclusion: CMV infection and HLA type are major risk factors for CD28^null CD4 T-cell-associated cardiovascular pathology. Increased numbers of CD28^null CD8 T-cells are also associated with CMV infection, but to a lesser extent. Aging, however, makes only a negligible contribution to the expansion of these T-cell subsets, and only in the presence of CMV infection. Our results open up new avenues for risk assessment, prevention, and treatment.

Impact of Treg on other T cell subsets in progression of fibrosis in experimental lung fibrosis

Idiopathic pulmonary fibrosis is an irreversible, progressive and lethal lung disease. Regulatory T cells (Tregs) and Th17 cells both are involved in lung fibrosis. But there are only few reports regarding the effect of Treg on other T cell subsets in experimental lung fibrosis. The aim of this study was to investigate the impact of Treg on Th17, CD4+CD28-T, CD4+CD28+T and CD8 + T cell subsets that could drive lung fibrosis. To reach the goal of our study, first we depleted Tregs by anti-CD25 mAb injection in experimental C57BL/6 mice model. It has been demonstrated in our study that depletion of Treg ameliorates bleomycin-induced lung fibrosis by immune modulating Th17 and other important T cell subsets response in lung. Our flow cytometry data revealed that the percentages of Th17, CD4+CD28-T, CD4+CD28+T and CD8 + T cell subsets were decreased in experimental lung fibrosis after Treg depletion. We also observed significant downregulation of IL-17 A in Treg-depleted mice after bleomycin delivery. In addition, the study also suggested that Treg depletion led to considerable upregulation of IFN-γ after bleomycin administration. Therefore, Th17 cells, CD8 + T cells, CD4+CD28- and CD4+CD28+ T cell subsets all are controlled by regulatory T cell, help in progression of fibrosis in experimental lung fibrosis.

Expansions of Cytotoxic CD4+CD28- T Cells Drive Excess Cardiovascular Mortality in Rheumatoid Arthritis and Other Chronic Inflammatory Conditions and Are Triggered by CMV Infection

A large proportion of cardiovascular (CV) pathology results from immune-mediated damage, including systemic inflammation and cellular proliferation, which cause a narrowing of the blood vessels. Expansions of cytotoxic CD4⁺ T cells characterized by loss of CD28 (“CD4⁺CD28⁻ T cells” or “CD4⁺CD28^null cells”) are closely associated with cardiovascular disease (CVD), in particular coronary artery damage. Direct involvement of these cells in damaging the vasculature has been demonstrated repeatedly. Moreover, CD4⁺CD28⁻ T cells are significantly increased in rheumatoid arthritis (RA) and other autoimmune conditions. It is striking that expansions of this subset beyond 1–2% occur exclusively in CMV-infected people. CMV infection itself is known to increase the severity of autoimmune diseases, in particular RA and has also been linked to increased vascular pathology. A review of the recent literature on immunological changes in CVD, RA, and CMV infection provides strong evidence that expansions of cytotoxic CD4⁺CD28⁻ T cells in RA and other chronic inflammatory conditions are limited to CMV-infected patients and driven by CMV infection. They are likely to be responsible for the excess CV mortality observed in these situations. The CD4⁺CD28⁻ phenotype convincingly links CMV infection to CV mortality based on a direct cellular-pathological mechanism rather than epidemiological association.

Decreased circulating neopterin is associated with increased arterial elasticity: a beneficial role of periodontal treatment

BACKGROUND

The aim of this study was to evaluate the effect of periodontal treatment on arterial elasticity and circulating neopterin in patients with moderate to severe periodontitis in a Chinese population.

METHODS

One hundred and eight patients with moderate to severe periodontitis were eligible to take part in the study and were randomized into two groups. The treatment group received intensive periodontal treatment, while the control group received control periodontal treatment. All parameters, including brachial-ankle pulse wave velocity (baPWV), ankle brachial index (ABI), serum neopterin (NP), high-sensitivity C-reactive protein (hs-CRP), Interleukin-6 (IL-6), were evaluated before treatment and 1 month after treatment.

RESULTS

The parameters including NP, hs-CRP, IL-6 and baPWV decreased significantly after 1 month in the treatment group (p < 0.05 for all comparisons) but not in the control group (p > 0.05). There was no significant difference in the change of ABI between the two groups (p = 0.231). A positive correlation was found between the decreased circulating NP and increased arterial elasticity in the treatment group (r = 0.947, p < 0.001).

CONCLUSIONS

This study demonstrates for the first time that the fall in circulating NP induced by periodontal treatment contributes to increased arterial elasticity in patients with moderate and severe periodontitis.

The story of CD4+ CD28- T cells revisited: solved or still ongoing?

CD4⁺CD28⁻ T cells are a unique type of proinflammatory T cells characterised by blockade of costimulatory CD28 receptor expression at the transcriptional level, which is still reversible by IL-12. In healthy individuals older than 65 years, these cells may accumulate to up to 50% of total CD4⁺ T lymphocytes as in many immune-mediated diseases, immunodeficiency, and specific infectious diseases. Here we focus on CD4⁺CD28⁻ T cells in chronic immune-mediated diseases, summarizing various phenotypic and functional characteristics, which vary depending on the underlying disease, disease activity, and concurrent treatment. CD4⁺CD28⁻ T cells present as effector/memory cells with increased replicative history and oligoclonality but reduced apoptosis. As an alternative costimulatory signal instead of CD28, not only natural killer cell receptors and Toll-like receptors, but also CD47, CTLA-4, OX40, and 4-1BB have to be considered. The proinflammatory and cytotoxic capacities of these cells indicate an involvement in progression and maintenance of chronic immune-mediated disease. So far it has been shown that treatment with TNF-α blockers, abatacept, statins, and polyclonal antilymphocyte globulins (ATG) mediates reduction of the CD4⁺CD28⁻ T cell level. The clinical relevance of targeting CD4⁺CD28⁻ T cells as a therapeutic option has not been examined so far.

Sex differences in independent factors associated with coronary artery disease

BACKGROUND

Women undergoing coronary angiography (CA) due to chest pain are more likely to present with less extensive coronary artery disease (CAD) than men, which might be attributed to different effects of cardiovascular risk factors on coronary atherogenesis between sexes. The aim of the present study was to evaluate sex differences in independent factors associated with obstructive and non-obstructive CAD in a large consecutive cohort of patients undergoing elective CA.

METHODS

Data from 7819 patients (2653 women and 5184 men), including cardiovascular risk factors, clinical presentation, CAD severity and treatment decisions were analysed.

RESULTS

Women were older than men (65 ± 11 vs. 63 ± 11 years, p < 0.001); low-density lipoprotein cholesterol (LDL; 125 ± 38 vs. 122 ± 37 mg/dL, p < 0.001) and high-density lipoprotein cholesterol (HDL) cholesterol levels (62 ± 18 vs. 51 ± 15 mg/dL, p < 0.001) were higher in women; and smokers were more frequently men (14.4 vs. 20.1%, p < 0.001). Men more frequently had an obstructive CAD (41.1 vs. 65.6%, p < 0.001). Multivariable analyses revealed age, HDL cholesterol, hypercholesterolaemia, diabetes mellitus, arterial hypertension and a positive family history being associated with obstructive CAD in both sexes, whereas smoking was independently associated with obstructive CAD only in women. The association of hypercholesterolaemia with obstructive CAD was stronger in men. For non-obstructive CAD, no sex-specific associated factors could be identified.

CONCLUSION

The impact of smoking and hypercholesterolaemia on coronary atherosclerosis is different between women and men. This might be taken into account when planning individual interventions to reduce cardiovascular risk.

How immunosuppressive therapy affects T cells from kidney transplanted patients of different age: the role of latent cytomegalovirus infection

The average age of patients receiving renal transplantation is increasing as programmes have been established which support the donation of organs from elderly donors to older recipients. Little is known about the effect of immunosuppressive therapy on the immune system of older patients. In this study, T cell function and the composition of the T cell repertoire were analysed in immunosuppressed renal transplant recipients of different age and cytomegalovirus (CMV) status in comparison to age- and CMV-matched controls. Independent of age and CMV status, the production of interleukin (IL)-2 and interferon (IFN)-γ by T cells was decreased in the patient groups and autologous serum from patients was capable of inhibiting the proliferation of CD3⁺ T cells. CXCR5 expression on T cells was increased in patients versus controls reflecting reduced endogenous IL-2 signalling under immunosuppressive therapy. In CMV-seronegative patients kidney transplantation and immunosuppressive therapy did not induce changes in the CD8⁺ T cell pool, but there was a moderate increase in CD4⁺CD28⁻ effector T cells when compared to age-matched controls. In contrast, latent CMV infection triggered a shift from early to late differentiated CD4⁺ and CD8⁺ T cells in patients and controls. This shift was most pronounced in elderly transplant patients under immunosuppressive therapy. In conclusion, our results demonstrate that immunosuppressive therapy following kidney transplantation is effective in patients older than 65 years. Latent CMV infection, however, accelerates age-related changes in the T cell repertoire in elderly people under immunosuppressive therapy. These patients should therefore be monitored with special care.

Circulating cells as predictors of secondary manifestations of cardiovascular disease: design of the CIRCULATING CELLS study

Biomarkers for primary or secondary risk prediction of cardiovascular disease (CVD) are urgently needed to improve individual treatment and clinical trial design. The vast majority of biomarker discovery studies has concentrated on plasma/serum as an easily accessible source. Although numerous markers have been identified, their added predictive value on top of traditional risk factors has been limited, as the biological specimen does not specifically reflect expression profiles related with CVD progression and because the signal is often diluted by marker release from other organs. In contrast to serum markers, circulating cells serve as indicators of the actual disease state due to their active role in the pathogenesis of CVD and are responsible for the majority of secreted biomarkers. Therefore, the CIRCULATING CELLS study was initiated, focusing on the cellular effectors of atherosclerosis in the circulation. In total, 714 patients with coronary artery disease (CAD) symptoms were included. Blood cell fractions (monocytes, T-lymphocytes, platelets, granulocytes, PBMC) of all individual patients were isolated and stored for analysis. Concomitantly, extensive flow cytometric characterization of these populations was performed. From each patient, a detailed clinical profile together with extensive questionnaires about medical history and life style was obtained. Various high-throughput -omics approaches (protein, mRNA, miRNA) are currently being undertaken. Data will be integrated with advanced bioinformatics for discovery and validation of secondary risk markers for adverse events. Overall, the CIRCULATING CELLS study grants the interesting possibility that it will both identify novel biomarkers and provide useful insights into the pathophysiology of CAD in patients.

Effects of drospirenone-ethinylestradiol and/or metformin on CD4(+)CD28(null) T lymphocytes frequency in women with hyperinsulinemia having polycystic ovary syndrome: a randomized clinical trial

OBJECTIVE

To evaluate the long-term effects of drospirenone (DRSP)/ethinylestradiol (EE) alone, metformin alone, and DRSP/EE-metformin on CD4(+)CD28(null) T lymphocytes frequency, a cardiovascular risk marker, in patients with hyperinsulinemic polycystic ovary syndrome (PCOS).

DESIGN

Randomized clinical trial.

INTERVENTIONS

Ninety three patients with hyperinsulinemic PCOS were age matched and body mass index matched and randomized to receive a 6 months daily treatment with DRSP (3 mg)/EE (0.03 mg), or metformin (1500 mg), or DRSP/EE combined with metformin.

MAIN OUTCOME MEASURES

CD4(+)CD28(null) T-cell frequencies.

RESULTS

The DRSP/EE and metformin groups did not show any significant change in the CD4(+)CD28(null) frequency compared to the baseline. Interestingly, a statistically significant decrease in CD4(+)CD28(null) frequency occurred after 6 months of DRSP/EE-metformin (median 3-1.5; P < .01). Of note, this statistically significant association was confirmed after adjusting for baseline values in DRSP/EE-metformin group by analysis of covariance (P < .05).

CONCLUSIONS

In women with hyperinsulinemic PCOS, combined therapy with DRSP/EE and metformin may reduce cardiovascular risk.

CD4(+)CD28(null) T lymphocyte frequency, a new marker of cardiovascular risk: relationship with polycystic ovary syndrome phenotypes

OBJECTIVE

To study the frequency of CD4(+)CD28(null) T cells, which are aggressive T lymphocytes associated with recurrent coronary instability and type 2 diabetes mellitus, in different polycystic ovary syndrome (PCOS) phenotypes and in age- and body mass index-matched healthy women.

DESIGN

Retrospective cohort observational study.

SETTING

Unit of human reproductive pathophysiology, university hospital.

PATIENT(S)

A total of 167 PCOS patients and 102 control subjects.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

CD4(+)CD28(null) T cell frequency, high-sensitive C-reactive protein levels, and other glucose-metabolic parameters.

RESULT(S)

CD4(+)CD28(null) frequency was significantly higher in all PCOS groups than in control subjects. CD4(+)CD28(null) frequency was significantly higher in nonhyperandrogenic phenotype (5.7%, range 3.2-7.1) than in phenotypes with hyperandrogenism (H) + oligoamenorrhea (O) + polycystic ovary (PCO) (3.5%, range 1-5.8), H + O (3%, range 1.8-4.7), and H + PCO (2.63%, range 1.2-4.1). The relative risk of non-H phenotype for PCOS women in the highest quartile for CD4(+)CD28(null) frequency compared with PCOS women with the lowest quartile was 3.2 (95% confidence interval 1.9-5.8).

CONCLUSION(S)

Cardiovascular risk evaluation should be performed in all PCOS phenotypes. In particular, we demonstrated that the non-H phenotype has potentially increased cardiovascular risk in terms of CD4(+)CD28(null) frequency.

Association between serum neopterin and inflammatory activation in chronic kidney disease

Background. The serum levels of neopterin, a marker associated with cell-mediated immunity are elevated in chronic kidney disease (CKD). We evaluated serum neopterin levels and investigated its association with markers of inflammation in a cross-section of CKD subjects without known cardiovascular disease. Methods. Serum neopterin levels were measured in 118 patients with stage 3–5 CKD and 41 healthy subjects with normal kidney function (HC). Patients with known cardiovascular disease were excluded. We also estimated highly sensitive CRP (hsCRP) and interluekin-6 (IL-6), tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) in the CKD subjects. All assays were done using commercially available ELISA kits. The correlation between neopterin and markers of inflammation were investigated. Results. Of the CKD population, 82 were in stage 5 (60 stage 5 D), 24 in stage 4, and 12 in stage 3. The mean age was 51.04 ± 1.3 years and 66% were males. The commonest cause of CKD was diabetes (36%). Serum neopterin levels were 5-fold higher in CKD patients as compared to HC (74.8 ± 3.6 versus 15.0 ± 2.8 nmol/L, P < 0.0001). There was a graded increase of serum neopterin from stages 3 to 4 and 5. CKD 5 D patients exhibited significantly higher levels compared to nondialysis stage 5 patients (P < 0.0001). An inverse correlation was noted between serum neopterin and eGFR (r = −0.359, P < 0.0001). Serum neopterin correlated with hsCRP (r = 0.285, P = 0.002), IL-6 (r = 0.212, P = 0.034), and IFN-γ (r = 0.32, P = 0.001) but not with TNF-α. Conclusion. Serum neopterin level is elevated and correlates with the severity of CKD. The elevation correlates with elevation of most, but not all, inflammatory markers. Its role in future development of cardiovascular disease and modulation with anti-inflammatory therapies needs further studies.

Elevated circulating interleukin-27 in patients with coronary artery disease is associated with dendritic cells, oxidized low-density lipoprotein, and severity of coronary artery stenosis

Coronary artery disease (CAD) is an immune-mediated chronic inflammatory disease mainly caused by atherosclerosis. The aims of this study were to investigate the role of interleukin-27 (IL-27) in patients with CAD and the severity of coronary artery lesions, which was evaluated by Gensini score and to investigate the biosynthesis of IL-27 and oxidized low-density lipoprotein (ox-LDL) in vitro using monocyte-derived dendritic cells (DCs). To this aim, plasma levels of IL-27, ox-LDL, and Gensini score were analyzed in patients with CAD (n = 136) and normal subjects (controls, n = 29). IL-27 concentration of the supernatant and the mRNA expression levels of p28 and ebi3, subunits of IL-27, from cultured immature DCs incubated with different concentrations of ox-LDL for 24 h were also analyzed. We found that circulating IL-27 levels were significantly elevated in patients with CAD than in controls (P < 0.01), and positively correlated to ox-LDL and Gensini score. ox-LDL dose-dependently upregulated expression of both IL-27 protein and IL-27 (p28 and EBI3) mRNA in vitro, indicating that ox-LDL can stimulate DCs to produce IL-27. These results demonstrate that IL-27 might regulate the network of immunity and inflammation in the pathogenesis of atherosclerosis.

Pathogenic features of CD4+CD28- T cells in immune disorders

Aging of the immune system contributes to the increased morbidity and mortality of the elderly population and may occur prematurely in patients with immune disorders. One of the main characteristics of immunosenescence is the expansion of CD4(+)CD28(-) T cells in the blood. These cells are effector memory T cells with cytotoxic capacity, and have been recently described to have pathogenic potential in a variety of immune disorders. Interestingly, CD4(+)CD28(-) T cells have now been found to infiltrate target tissues of patients with multiple sclerosis, rheumatoid arthritis, myopathies, acute coronary syndromes, and other immune-related diseases. In this review, we discuss potential factors and mechanisms that may induce the expansion of these cells, as well as their putative pathogenic mechanisms in immune disorders.

Cytomegalovirus-induced effector T cells cause endothelial cell damage

Human cytomegalovirus (CMV) infection has been linked to inflammatory diseases that involve vascular endothelial cell damage, but definitive proof for a direct cytopathic effect of CMV in these diseases is lacking. CMV infection is associated with a strong increase in both CD4(+) and CD8(+) T cells with constitutive effector functions that can perpetuate systemic inflammation. We investigated whether CMV-induced immune responses could lead to endothelial damage in humans. We found that terminally differentiated effector CD4(+) and CD8(+) T cells, formed during primary CMV infection and maintained throughout latency, express high levels of CX3CR1 and CXCR3. The ligands of these receptors, fractalkine and IP-10, respectively, are expressed by activated endothelial cells. Peripheral blood mononuclear cells (PBMC) stimulated with CMV antigen produced soluble factors that stimulated endothelial cells to produce both chemokines. Finally, effector cells migrated in a fractalkine- and IP-10-dependent fashion to activated endothelial cells and induced apoptosis in endothelial cells that were stimulated by supernatant from CMV-activated PBMC. Our findings offer an explanation for the accumulation of highly differentiated T cells near to the endothelium in CMV-infected individuals that may result in endothelial damage.

CD4+CD28null cells are expanded and exhibit a cytolytic profile in end-stage renal disease patients on peritoneal dialysis

BACKGROUND

End-stage renal failure patients, including those on peritoneal dialysis (PD), exhibit several nontraditional cardiovascular (CV) risk factors. A role of CD4(+)CD28(null) T lymphocytes in the genesis of coronary artery disease (CAD) has been proposed. We investigated this cell population and examined its phenotype in a cohort of PD patients without CV disease.

METHODS

The frequency of the peripheral blood CD4(+)CD28(null) T-cell compartment and cytotoxic characteristic of these cells (as assessed by perforin and granzyme B expressions) were determined in 33 PD patients without CAD and 20 healthy subjects by two- and three-color flowcytometry. High-sensitivity C-reactive protein (hs-CRP) was determined by enzyme-linked immunosorbent assay. We investigated whether there was a correlation between these cells and traditional CV risk factors.

RESULTS

Compared to healthy controls, CD4(+)CD28(null) T cells were significantly expanded in PD patients (10.30 ± 2.03% versus 3.55 ± 0.67%, mean ± SE, P = 0.0007). Perforin and granzyme B expressions were restricted to CD4(+)CD28(null) T cells compared to CD4(+)CD28(+) T cells (<0.0001). A greater proportion of CD4(+)CD28(null) T cells in PD patients expressed these molecules (P = 0.007 and 0.04). hs-CRP level was increased in PD patients (P < 0.0001) but did not correlate with the CD4(+)CD28(null) T-cell frequency. Increasing age correlated with the CD4(+)CD28(null) cells.

CONCLUSIONS

PD patients exhibit a substantially increased number of circulating CD4(+)CD28(null) T cells that show a cytolytic profile before the onset of clinically significant CAD. Their significance as a nontraditional CV risk factor needs further studies.

Serum neopterin is not increased in obese juveniles

Objective. Cardiovascular disease is associated with inflammation and immune activation, concentrations of immune activation markers like neopterin predict outcome in adults. Methods. Serum neopterin concentrations and early metabolic and pre-atherosclerotic symptoms were analyzed in 295 obese juveniles and 101 normal weight controls of similar age. Additionally, the influence of a 12 months weight reduction program on neopterin levels was investigated in 31 obese juveniles. Results. Intima-media thickness of common carotid arteries (IMT) and the concentrations of C-reactive protein (CRP) were increased in the obese juveniles (P < .001). Also triglycerides, oxidized LDL, fasted insulin levels, HOMA-index, leptin, liver transaminases and uric acid were increased compared to the controls. However, serum neopterin was decreased in the obese versus non-obese juveniles (P < .03). The intervention consisting of regular sports, nutritional devices, and a psychologic attendance led after 12 months to an increase of neopterin concentration (P < .05; paired test). Conclusions. Neopterin concentrations in juvenile obesity behaved considerably different from what was demonstrated in adults, levels did not correlate with metabolic and pre-atherosclerotic symptoms found in early phases although early vascular burden and chronic low grade inflammation was indicated by increased IMT and CRP. Neopterin concentrations increased after a 12 months intervention program.