CD14 and toll-like receptor 4: a link between infection and acute coronary events?

Nattokinase attenuates endothelial inflammation through the activation of SRF and THBS1

Natto contains a potent fibrinolytic enzyme called nattokinase (NK), which has thrombolytic, antihypertensive, antiatherosclerotic and lipid-lowering effects. Although NK has been recognized for its beneficial effect on humans with atherosclerotic cardiovascular disease (ASCVD), the underlying mechanisms involved in vascular inflammation-atherosclerosis development remain largely unknown. The current study aimed to explore the effects of NK on gene regulation, autophagy, necroptosis and inflammasome in vascular inflammation. The transcriptional profiles of NK in endothelial cells (ECs) by RNA sequencing (RNA-seq) revealed that NK affected THBS1, SRF and SREBF1 mRNA expression. In Q-PCR analysis, SRF and THBS1 were upregulated but SREBF1 was unaffected in ECs treated with NK. NK treatment induced autophagy and inhibited NLRP3 inflammasome and necroptosis in ECs. Furthermore, the inhibition of SRF or THBS1 by siRNA suppressed autophagy and enhanced the NLRP3 inflammasome and necroptosis. In a mouse model, NK reduced vascular inflammation by activating autophagy and inhibiting NLRP3 inflammasome and necroptosis. Our findings provide the first evidence that NK upregulates SRF and THBS1 genes, subsequently increasing autophagy and decreasing necroptosis and NLRP3 inflammasome formation to reduce vascular inflammation. Therefore, NK could serve as nutraceuticals or adjuvant therapies to reduce vascular inflammation and possible atherosclerosis progression.

High-dose oral vitamin D supplementation for prevention of infections in children aged 0 to 59 months: a systematic review and meta-analysis

CONTEXT

Vitamin D plays an important role in immune function, and the deficiency thereof has been associated with several infections, most notably respiratory tract infections. However, data from intervention studies investigating the effect of high-dose vitamin D supplementation on infections have been inconclusive.

OBJECTIVE

The aim of this study was to evaluate the level of evidence regarding the efficacy of vitamin D supplementation above the standard dose (400 IU) in preventing infections in apparently healthy children < 5 years of age.

DATA SOURCES

PubMed, Scopus, Science Direct, Web of Science, Google Scholar, CINAHL, and MEDLINE electronic databases were searched between August 2022 and November 2022. Seven studies met the inclusion criteria.

DATA EXTRACTION

Meta-analyses of outcomes in more than one study were performed using Review Manager software. Heterogeneity was evaluated using the I2 statistic. Randomized controlled trials in which vitamin D was supplemented at > 400 IU compared with placebo, no treatment, or standard dose were included.

DATA ANALYSIS

Seven trials that enrolled a total of 5748 children were included. Odds ratios (ORs) with 95%CIs were calculated using random- and fixed-effects models. There was no significant effect of high-dose vitamin D supplementation on the incidence of upper respiratory tract infection (OR, 0.83; 95%CI, 0.62-1.10). There was a 57% (95%CI, 0.30-0.61), 56% (95%CI, 0.27-0.07), and 59% (95%CI, 0.26-0.65) reduction in the odds of influenza/cold, cough, and fever incidence, respectively, with daily supplementation of vitamin D > 1000 IU. No effect was found on bronchitis, otitis media, diarrhea/gastroenteritis, primary care visits for infections, hospitalizations, or mortality.

CONCLUSION

High-dose vitamin D supplementation provided no benefit in preventing upper respiratory tract infections (moderate certainty of evidence) but reduced the incidence influenza/cold (moderate certainty of evidence), cough, and fever (low certainty of evidence). These findings are based on a limited number of trials and should be interpreted with caution. Further research is needed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42022355206.

Host immunity associated with spontaneous suppression of viremia in therapy-naïve young rhesus macaques following neonatal SHIV infection

IMPORTANCE

Despite the advent of highly active anti-retroviral therapy, people are still dying from HIV-related causes, many of whom are children, and a protective vaccine or cure is needed to end the HIV pandemic. Understanding the nature and activation states of immune cell subsets during infection will provide insights into the immunologic milieu associated with viremia suppression that can be harnessed via therapeutic strategies to achieve a functional cure, but these are understudied in pediatric subjects. We evaluated humoral and adaptive host immunity associated with suppression of viremia in rhesus macaques infected soon after birth with a pathogenic SHIV. The results from our study provide insights into the immune cell subsets and functions associated with viremia control in young macaques that may translate to pediatric subjects for the design of future anti-viral strategies in HIV-1-infected infants and children and contribute to an understudied area of HIV-1 pathogenesis in pediatric subjects.

Exploring the effect of Weifuchun capsule on the toll-like receptor pathway mediated HES6 and immune regulation against chronic atrophic gastritis

ETHNOPHARMACOLOGICAL RELEVANCE

Weifuchun capsule (WFC) is a traditional Chinese patent medicine for chronic atrophic gastritis (CAG) in clinic. However, the mechanism of action of WFC for CAG still remains unclear due to its complex composition.

AIM OF THE STUDY

The study was projected to uncover the mechanism of action of WFC and the corresponding pharmacodynamic substance of WFC against CAG as well as providing a standard example for the research of traditional Chinese medicine (TCM) from the perspective of the network and the system.

MATERIALS AND METHODS

We identified the compounds of WFC through LC-MS/MS analysis and performed a systematic network targets analysis for WFC in the treatment of CAG which thoroughly described the mechanism of action of WFC for CAG. Based on analysis integrating omics data and algorithms, we focused on the specific immune regulatory role of WFC in the treatment of CAG, especially on a hub pathway, Toll-like receptor signaling pathway and thus deciphered the role of WFC in immune regulation, anti-inflammation and mediation of HES6. In experiments part, MNNG-GES-1-cell line and rat models were used to validate our findings.

RESULTS

In this study, compounds of WFC are identified through LC‒MS/MS and network target analysis is performed to dissect the specific immunoregulatory effect as well as mediation of HES6, a newly discovered biomolecule related to gastritis carcinoma progression, of WFC on CAG through the Toll-like receptor signaling pathway. Based on cell line and rat models, we verify the mechanism of action of WFC for CAG in inhibiting inflammatory cytokines, regulating immune cells like T cells and macrophages, related genes including TLR2 and CD14. It is also validated that WFC inhibits the expression of HES6 (P < 0.05).

CONCLUSION

Based on the combination of computational strategy and experiments, our study offers a comprehensive analysis to reveal the role of WFC in regulating immune response, inhibiting inflammation in the treatment of CAG, and provides a standard example for the research of TCM from the perspective of the network and the system.

Perinatal presepsin assessment: a new sepsis diagnostic tool?

Perinatal sepsis constitutes a medical emergency and is still one of the major causes of mortality and morbidity. The possibility of an early diagnosis of sepsis is still debated and controversial. In particular, clinical symptoms can be hidden by the association of sepsis with other perinatal diseases and/or by therapeutic strategies performed. In this context, there is evidence that the accuracy of standard of care diagnostic parameters (i.e. blood culture, C-reactive protein, procalcitonin) can be biased by additional confounding factors (gestational age, birth-weight, acute-chronic hypoxia). Therefore, the inclusion in clinical daily practice of new biomarkers of sepsis is of utmost importance. Of a panel of biomarkers, Presepsin (P-SEP) plays an important role in the development and response of the immune system and as an early marker of sepsis both in adult and pediatric patients. Therefore, in the present review we aim to offer an overview of the role of P-SEP in the early detection of perinatal sepsis as a trustworthy marker according to actual statements of official international institutions. Future perspectives regard the possibility of a longitudinal non-invasive biological fluids P-SEP assessment thus limiting the sample stress in high risk newborns.

Modulation of gene expression on a transcriptome-wide level following human neural stem cell transplantation in aged mouse stroke brains

INTRODUCTION

Neural stem cell (NSC) transplantation offers great potential for treating ischemic stroke. Clinically, ischemia followed by reperfusion results in robust cerebrovascular injury that upregulates proinflammatory factors, disrupts neurovascular units, and causes brain cell death. NSCs possess multiple actions that can be exploited for reducing the severity of neurovascular injury. Our previous studies in young adult mice showed that human NSC transplantation during the subacute stage diminishes stroke pathophysiology and improves behavioral outcome.

METHODS

We employed a well-established and commonly used stroke model, middle cerebral artery occlusion with subsequent reperfusion (MCAO/R). Here, we assessed the outcomes of hNSC transplantation 48 h post-MCAO (24 h post-transplant) in aged mouse brains in response to stroke because aging is a crucial risk factor for cerebral ischemia. Next, we tested whether administration of the integrin α5β1 inhibitor, ATN-161, prior to hNSC transplantation further affects stoke outcome as compared with NSCs alone. RNA sequencing (RNA-seq) was used to assess the impact of hNSC transplantation on differentially expressed genes (DEGs) on a transcriptome-wide level.

RESULTS

Here, we report that hNSC-engrafted brains with or without ATN-161 showed significantly reduced infarct size, and attenuated the induction of proinflammatory factors and matrix metalloproteases. RNA-seq analysis revealed DEGs and molecular pathways by which hNSCs induce a beneficial post-stroke outcome in aged stroke brains. 811 genes were differentially expressed (651 downregulated and 160 upregulated) in hNSC-engrafted stroke brains. Functional pathway analysis identified enriched and depleted pathways in hNSC-engrafted aged mouse stroke brains. Depletion of pathways following hNSC-engraftment included signaling involving neuroinflammation, acute phase response, leukocyte extravasation, and phagosome formation. On the other hand, enrichment of pathways in hNSC-engrafted brains was associated with PPAR signaling, LXR/RXR activation, and inhibition of matrix metalloproteases. Hierarchical cluster analysis of DEGs in hNSC-engrafted brains indicate decreased expression of genes encoding TNF receptors, proinflammatory factors, apoptosis factors, adhesion and leukocyte extravasation, and Toll-like receptors.

CONCLUSIONS

Our study is the first to show global transcripts differentially expressed following hNSC transplantation in the subacute phase of stroke in aged mice. The outcome of our transcriptome study would be useful to develop new therapies ameliorating early-stage stroke injury.

Coronary atherosclerosis severity is closely associated with decreased GLP-1R positivity among CD16+ pro-inflammatory and patrolling monocyte subsets

Background and aims

Glucagon Like Peptide-1 Receptor (GLP-1R) activation reduces pro-inflammatory responses of human monocytes, their accumulation in the vascular wall and foam cell formation inhibiting atherosclerogenesis. This suggests that reduction of circulating GLP-1-1R positive monocytes may have pro-atherogenic effects. It is unknown whether different CD14/CD16 monocytes subsets display GLP-1R and whether their relative proportions correlate with atherosclerosis severity. We evaluated the association between GLP-1R positivity in different CD14/CD16 monocyte subsets and coronary atherosclerosis severity.

Methods

Relative amounts of classical (CD14+/CD16-), intermediate pro-inflammatory (CD14+/CD16+) and non-classical patrolling (CD14-/CD16+) subsets of total circulating monocytes and the proportions of GLP-1R positive monocytes in these subsets were determined in 13 control subjects and 10 dyslipidemic ischemic heart disease (IHD) patients with severe angiographic proven coronary atherosclerosis using flow cytometry analysis. Atherosclerosis severity was calculated by SYNTAX score.

Results

In univariable analysis, severe atherosclerosis was associated with decreased proportion of classical monocytes and two fold increased CD16⁺ pro-inflammatory and patrolling subsets as compared with controls (p = 0.01, p = 0.02 and p = 0.01, respectively). Frequency of GLP-1R positive monocytes was decreased in both CD16⁺ subsets (p = 0.02 and p = 0.05, respectively) and negatively correlated with atherosclerosis severity (r = -0.65, p = 0.005 and r = -0.44, p = 0.05, respectively).

Conclusions

Increased skewing of the classical monocyte population toward CD16⁺ pro-inflammatory and patrolling subsets accompanied by decreased in GLP-1R positivity are associated with coronary atherosclerosis severity in IHD patients with dyslipidemia. Although the effect of potential confounders cannot be ruled out, our data suggest that failure of GLP-1R-dependent anti-inflammatory/anti-atherogenic control results in innate immune system dysfunction and can promote atherosclerogenesis.

Immunomodulatory Function of Polyvinylpyrrolidone (PVP)-Functionalized Gold Nanoparticles in Vibrio-Stimulated Sea Urchin Immune Cells

We investigated the role of the gold nanoparticles functionalized with polyvinylpyrrolidone (PVP–AuNPs) on the innate immune response against an acute infection caused by Vibrio anguillarum in an in vitro immunological nonmammalian next-generation model, the sea urchin Paracentrotus lividus. To profile the immunomodulatory function of PVP–AuNPs (0.1 μg mL⁻¹) in sea urchin immune cells stimulated by Vibrio (10 μg mL⁻¹) for 3 h, we focused on the baseline immunological state of the donor, and we analysed the topography, cellular metabolism, and expression of human cell surface antigens of the exposed cells, as well as the signalling leading the interaction between PVP–AuNPs and the Vibrio-stimulated cells. PVP–AuNPs are not able to silence the inflammatory signalling (TLR4/p38MAPK/NF-κB signalling) that involves the whole population of P. lividus immune cells exposed to Vibrio. However, our findings emphasise the ability of PVP–AuNPs to stimulate a subset of rare cells (defined here as Group 3) that express CD45 and CD14 antigens on their surface, which are known to be involved in immune cell maturation and macrophage activation in humans. Our evidence on how PVP–AuNPs may stimulate sea urchin immune cells represents an important starting point for planning new research work on the topic.

Effect of Advanced Glycation End-Products and Excessive Calorie Intake on Diet-Induced Chronic Low-Grade Inflammation Biomarkers in Murine Models

Chronic Low-Grade Inflammation (CLGI) is a non-overt inflammatory state characterized by a continuous activation of inflammation mediators associated with metabolic diseases. It has been linked to the overconsumption of Advanced Glycation End-Products (AGEs), and/or macronutrients which lead to an increase in local and systemic pro-inflammatory biomarkers in humans and animal models. This review provides a summary of research into biomarkers of diet-induced CLGI in murine models, with a focus on AGEs and obesogenic diets, and presents the physiological effects described in the literature. Diet-induced CLGI is associated with metabolic endotoxemia, and/or gut microbiota remodeling in rodents. The mechanisms identified so far are centered on pro-inflammatory axes such as the interaction between AGEs and their main receptor AGEs (RAGE) or increased levels of lipopolysaccharide. The use of murine models has helped to elucidate the local and systemic expression of CLGI mediators. These models have enabled significant advances in identification of diet-induced CLGI biomarkers and resultant physiological effects. Some limitations on the translational (murine → humans) use of biomarkers may arise, but murine models have greatly facilitated the testing of specific dietary components. However, there remains a lack of information at the whole-organism level of organization, as well as a lack of consensus on the best biomarker for use in CLGI studies and recommendations as to future research conclude this review.

Soluble CD14 Subtype in Peripheral Blood is a Biomarker for Early Diagnosis of Sepsis

OBJECTIVE

To study the value of serum soluble CD14 subtype (sCD14-ST) in early diagnosis of sepsis.

METHODS

Seventy-two patients were diagnosed with systemic inflammatory response syndrome, sepsis, or septic shock. Peripheral blood was collected at 0, 12, 24, and 48 hours after admission to the hospital. Levels of sCD14-ST, procalcitonin (PCT), hypersensitive C-reactive protein (CRP), and white blood cells (WBC) were determined.

RESULTS

Levels of sCD14-ST in the patients with septic shock were higher than those in the other patients (P < .01) and peaked at 48 h. PCT and CRP levels were similar in the patients at admission but increased by 5 times to 10 times in the next 48 h, especially in the patients with septic shock. WBC levels remained high and did not change dramatically. Receiver operating characteristic analysis revealed that the area under the curve, sensitivity, and specificity values of sCD14-ST to diagnose sepsis were much higher than those of the other markers.

CONCLUSION

Compared with PCT, CRP, and WBC, sCD14-ST is a better biomarker for the early diagnosis of sepsis.

Monocytes and macrophages in ANCA-associated vasculitis

Anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitides (AAV) are characterized by inflammation of small-to-medium-sized blood vessels and the presence of autoantibodies against cytoplasmic proteases sited in neutrophils and monocytes. Increasing evidence indicates a substantial role of monocytes and macrophages in the pathogenesis of AAV. Activated monocytes and macrophages contribute to necroinflammation in peripheral vasculitic lesions as well as to central and peripheral mechanisms of autoimmunity. The intermediate monocyte subset (CD14⁺⁺CD16⁺) is increased and monocytes show elevated expression of CD14, Toll-like receptor 2/4, MHCII and integrins, likely reflecting activation and increased monocyte extravasation. Monocytes differentiate locally predominantly into alternatively activated (M2) macrophages, which are known for cell-clearance and phagocytosis, but may ultimately lead to fibrosis. Phagocytotic function of macrophages can be impaired by surface expression of cytoplasmic proteases on apoptotic neutrophils and causes release of inflammatory cytokines and immunogenic contents, presumably resulting in a vicious circle of increased neutrophil, T and B cell activation and consequent ANCA production. Considering their crucial role in initiating necroinflammation as well as fibrogenesis, monocytes and macrophages may represent a logic first-line target for new treatment options in AAV.

Complement activation is associated with poor outcome after out-of-hospital cardiac arrest

BACKGROUND

Cardiopulmonary resuscitation after cardiac arrest initiates a whole-body ischemia-reperfusion injury, which may activate the innate immune system, including the complement system. We hypothesized that complement activation and subsequent release of soluble endothelial activation markers were associated with cerebral outcome including death.

METHODS

Outcome was assessed at six months and defined by cerebral performance category scale (1-2; good outcome, 3-5; poor outcome including death) in 232 resuscitated out-of-hospital cardiac arrest patients. Plasma samples obtained at admission and day three were analysed for complement activation products C3bc, the soluble terminal complement complex (sC5b-9), and soluble CD14. Endothelial cell activation was measured by soluble markers syndecan-1, sE-selectin, thrombomodulin, and vascular cell adhesion molecule.

RESULTS

Forty-nine percent of the patients had good outcome. C3bc and sC5b-9 were significantly higher at admission compared to day three (p < 0.001 for both) and in patients with poor compared to good outcome (p = 0.03 and p < 0.001, respectively). Unadjusted, higher sC5b-9 at admission was associated with poor outcome (odds ratio 1.08 (95% CI 1.01-1.14), p = 0.024). Adjusted, sC5b-9 was still associated with outcome, but the association became non-significant when time to return-of-spontaneous-circulation above 25 min was included as a covariate. Endothelial cell activation markers increased from admission to day three, but only sE-selectin and thrombomodulin were significantly higher in patients with poor versus good outcome (p = 0.004 and p = 0.03, respectively) and correlated to sCD14 and sC5b-9/C3bc, respectively.

CONCLUSION

Complement system activation, reflected by sC5b-9 at admission, leading to subsequent endothelial cell activation, was associated with poor outcome in out-of-hospital cardiac arrest patients.

Role of Periodontal Infection, Inflammation and Immunity in Atherosclerosis

BACKGROUND

Inflammation plays a major role in the development and progression of cardiovascular disease (CVD) morbidity and mortality. The well-established relationship between periodontal disease (PD) and CVD may be causal. Left untreated, PD can lead to high systemic inflammation, thus contributing to inflammatory CVD, such as atherosclerosis. Multiple mechanisms have been proposed to elucidate the causal relationship between PD and its contribution to CVD.

OBJECTIVE

This review article highlights the current evidence supporting the role of PD in the development and progression of atherosclerosis.

METHODS

After creating a list of relevant medical subject heading (MeSH) terms, a systematic search within PubMed in English for each MeSH term between 2000 and 2019 was used to generate evidence for this review article.

CONCLUSION

There is overwhelming evidence in the current literature that supports an association between PD and CVD that is independent of known CVD risk factors. However, the supporting evidence that PD directly causes CVD in humans continues to remain elusive. Multiple biologically plausible mechanisms have been proposed and investigated, yet most studies are limited to mouse models and in vitro cell cultures. Additional studies testing the various proposed mechanisms in longitudinal human studies are required to provide deeper insight into the mechanistic link between these 2 related diseases.

The Multifaceted Nature of Streptococcal Antigen I/II Proteins in Colonization and Disease Pathogenesis

Streptococci are Gram-positive bacteria that belong to the natural microbiota of humans and animals. Certain streptococcal species are known as opportunistic pathogens with the potential to cause severe invasive disease. Antigen I/II (AgI/II) family proteins are sortase anchored cell surface adhesins that are nearly ubiquitous across streptococci and contribute to many streptococcal diseases, including dental caries, respiratory tract infections, and meningitis. They appear to be multifunctional adhesins with affinities to various host substrata, acting to mediate attachment to host surfaces and stimulate immune responses from the colonized host. Here we will review the literature including recent work that has demonstrated the multifaceted nature of AgI/II family proteins, focusing on their overlapping and distinct functions and their important contribution to streptococcal colonization and disease.

The role of innate immunity in Alzheimer's disease

The amyloid hypothesis has dominated Alzheimer's disease (AD) research for almost 30 years. This hypothesis hinges on the predominant clinical role of the amyloid beta (Aβ) peptide in propagating neurofibrillary tangles (NFTs) and eventual cognitive impairment in AD. Recent research in the AD field has identified the brain-resident macrophages, known as microglia, and their receptors as integral regulators of both the initiation and propagation of inflammation, Aβ accumulation, neuronal loss, and memory decline in AD. Emerging studies have also begun to reveal critical roles for distinct innate immune pathways in AD pathogenesis, which has led to great interest in harnessing the innate immune response as a therapeutic strategy to treat AD. In this review, we will highlight recent advancements in our understanding of innate immunity and inflammation in AD onset and progression. Additionally, there has been mounting evidence suggesting pivotal contributions of environmental factors and lifestyle choices in AD pathogenesis. Therefore, we will also discuss recent findings, suggesting that many of these AD risk factors influence AD progression via modulation of microglia and immune responses.

Chemerin facilitates intervertebral disc degeneration via TLR4 and CMKLR1 and activation of NF-kB signaling pathway

Now days, obesity is a major risk factor for intervertebral disc degeneration (IDD). However, adipokine, such as chemerin is a novel cytokine, which is secreted by adipose tissue, and are thought to be played major roles in various degenerative diseases. Obese individuals are known to have high concentration of serum chemerin. Our purpose was to study whether chemerin acts as a biochemical relationship between obesity, and IDD. In this study, we found that the expression level of chemerin was significantly increased in the human degenerated nucleus pulposus (NP) tissues, and had higher level in the obese people than the normal people. Chemerin significantly increased the inflammatory mediator level, contributing to ECM degradation in nucleus pulposus cells (NPCs). Furthermore, chemerin overexpression aggravates the puncture-induced IVDD progression in rats, while knockdown CMKLR1 reverses IVDD progression. Chemerin activates the NF-kB signaling pathway via its receptors CMKLR1, and TLR4 to release inflammatory mediators, which cause matrix degradation, and cell aging. These findings generally provide novel evidence supporting the causative role of obesity in IDD, which is essentially important to literally develop novel preventative or generally therapeutic treatment in the disc degenerative disorders.

A Single Step in vitro Bioassay Mimicking TLR4-LPS Pathway and the Role of MD2 and CD14 Coreceptors

Acute systemic Gram-negative bacterial infections are accompanied by release of lipopolysaccharide (LPS) endotoxins into the bloodstream and an innate immune host response via the well-known toll like receptor 4 (TLR4) pathway. In this, LPS associates non-covalently with TLR4 to form an activated heterodimer (LPS/MD2/TLR4)₂ complex in vivo, assisted by a coreceptor CD14. This complexation process has been illustrated ex vivo using indirect methods such as cytokine, interleukin, TNF-α measurements and by direct demonstration of sequential binding events on a surface using advanced optics. We are the first ones to carry out homogeneous self-assembly of LPS-rTLR4-MD2 conjugates in vitro in a single step, and further demonstrate the role of CD14 as a catalyst during this process. The assay comprises of LPS, MD2, CD14, and recombinant TLR4-conjugated magnetic particles co-incubated in a buffer at room temperature. The complexes are removed by magnetic separation and the extent of binding is estimated by quantifying the unbound biomolecules in the supernatant using standard biophysical techniques. Our results show that rTLR4-MD2-LPS complexes form in an hour and follow a 1:1:1 stoichiometry, in agreement with the in vivo/ex vivo studies. The assay is also highly specific; addition of known LPS-binding ligands decreased the LPS-rTLR4 complexation, allowing its use as a rapid tool for molecular inhibitor screening.

The Effect of Gamma-Ray-Induced Central Nervous System Injury on Peripheral Immune Response: An In Vitro and In Vivo Study

Radiotherapy to treat brain tumors can potentially harm the central nervous system (CNS). The radiation stimulates a series of immune responses in both the CNS as well as peripheral immune system. To date, studies have mostly focused on the changes occurring in the immune response within the CNS. In this study, we investigated the effect of γ-ray-induced CNS injury on the peripheral immune response using a cell co-culture model and a whole-brain irradiation (WBI) rat model. Nerve cells (SH-SY5Y and U87 MG cells) were γ-ray irradiated, then culture media of the irradiated cells (conditioned media) was used to culture immune cells (THP-1 cells or Jurkat cells). Analyses were performed based on the response of immune cells in conditioned media. Sprague-Dawley rats received WBI at different doses, and were fed for one week to one month postirradiation. Spleen and peripheral blood were then isolated and analyzed. We observed that the number of monocytes in peripheral blood, and the level of NK cells and NKT cells in spleen increased after CNS injury. However, the level of T cells in spleen did not change and the level of B cells in the spleen decreased after γ-ray-induced CNS injury. These findings indicate that CNS injury caused by ionizing radiation induces a series of changes in the peripheral immune system.

Gene expression profiling of lichenoid dermatitis immune-related adverse event from immune checkpoint inhibitors reveals increased CD14+ and CD16+ monocytes driving an innate immune response

BACKGROUND

Cancer patients receiving antibodies abrogating immune checkpoint pathways may develop a diverse array of immune-related adverse events (irAEs), of which lichenoid dermatitis (LD) is the most common. The mechanism driving the emergence of these irAEs remain understudied, underscoring a critical need to determine the unique gene expression profiles and immune composition in LD-irAE.

METHODS

LD-irAE (n = 3) and benign lichenoid keratosis (BLK) control (n = 3) were profiled with NanoString nCounter PanCancer Immune Profiling Panel interrogating the mRNA levels of 770 genes. Immunohistochemical (IHC) studies (n = 14 samples) for CD14, CD16, T-Bet, Gata-3, and FoxP3 were further evaluated using Aperio digital image analysis.

RESULTS

The LD-irAE showed downregulation of 93 mRNA transcripts (P < 0.05) and upregulation of 74 mRNA transcripts (P < 0.04) including toll-like receptor (TLR) 2 and TLR4 (P < 0.05). CD14⁺ and CD16⁺ monocytes quantified by IHC (H-score) were higher in LD-irAE than in the BLK control (P < 0.05). The immune composition of LD-irAE exhibited higher numbers of T-Bet⁺ (Th1) cells compared with Gata-3⁺ (Th2) cells (P = 0.016) and lower numbers of FoxP3 (T regulatory) cells (P = 0.008).

CONCLUSIONS

LD-irAE exhibited activation of CD14/TLR innate immune response with increased CD14⁺ and CD16⁺ monocytes compared with BLK control. CD14/TLR signaling may drive the development of LD-irAE.

Role of intestinal microbiota in the formation of non-alcoholic fatty liver disease

The article provides an overview of modern views on the role of intestinal microbiota in the formation of non-alcoholic fatty liver disease. The general questions of the pathogenesis of the syndrome of excessive bacterial growth in the intestine, the participation of opportunistic microflora, the deficit of representatives of normal microflora, changes in the species composition of bile acids in the pathogenesis of nonalcoholic fatty liver disease are considered.

Endotoxin, Toll-like Receptor-4, and Atherosclerotic Heart Disease

Background:

Endotoxin is a lipopolysaccharide (LPS) constituent of the outer membrane of most gram negative bacteria. Ubiquitous in the environment, it has been implicated as a cause or con-tributing factor in several disparate disorders from sepsis to heatstroke and Type II diabetes mellitus. Starting at birth, the innate immune system develops cellular defense mechanisms against environmen-tal microbes that are in part modulated through a series of receptors known as toll-like receptors. Endo-toxin, often referred to as LPS, binds to toll-like receptor 4 (TLR4)/ myeloid differentiation protein 2 (MD2) complexes on various tissues including cells of the innate immune system, smooth muscle and endothelial cells of blood vessels including coronary arteries, and adipose tissue. Entry of LPS into the systemic circulation ultimately leads to intracellular transcription of several inflammatory mediators. The subsequent inflammation has been implicated in the development and progression atherosclerosis and subsequent coronary artery disease and heart failure.

Objective:

The potential roles of endotoxin and TLR4 are reviewed regarding their role in the pathogen-esis of atherosclerotic heart disease.

Conclusion:

Atherosclerosis is initiated by inflammation in arterial endothelial and subendothelial cells, and inflammatory processes are implicated in its progression to clinical heart disease. Endotoxin and TLR4 play a central role in the inflammatory process, and represent potential targets for therapeutic intervention. Therapy with HMG-CoA inhibitors may reduce the expression of TLR4 on monocytes. Other therapeutic interventions targeting TLR4 expression or function may prove beneficial in athero-sclerotic disease prevention and treatment.

The Metabolic Role of Gut Microbiota in the Development of Nonalcoholic Fatty Liver Disease and Cardiovascular Disease

The prevalence of metabolic disorders, such as type 2 diabetes (T2D), obesity, and non-alcoholic fatty liver disease (NAFLD), which are common risk factors for cardiovascular disease (CVD), has dramatically increased worldwide over the last decades. Although dietary habit is the main etiologic factor, there is an imperfect correlation between dietary habits and the development of metabolic disease. Recently, research has focused on the role of the microbiome in the development of these disorders. Indeed, gut microbiota is implicated in many metabolic functions and an altered gut microbiota is reported in metabolic disorders. Here we provide evidence linking gut microbiota and metabolic diseases, focusing on the pathogenetic mechanisms underlying this association.

Association between CD14 SNP -159 C/T and gastric cancer: an independent case-control study and an updated meta-analysis

PURPOSE

The association between CD14 -159C/T polymorphism and the susceptibility to gastric cancer (GC) has been reported. However, the results were inconclusive. In the present study, a case-control study and a meta-analysis were performed to assess the possible association between -159C/T in the CD14 gene and GC risk.

PATIENTS AND METHODS

Relevant studies were searched in several databases including PubMed, Web of Science, EMBASE, Chinese National Knowledge Infrastructure database, and Wanfang database (last search was performed on December 30, 2015). In addition, a case-control study involving 164 GC cases and 169 controls was also performed in the analysis. Statistical analysis was performed by the software Revman5.3.

RESULTS

A total of ten published studies and the present case-control study involving 2,844 GC and 3,983 controls were included for the meta-analysis. The analysis result indicated that the T allele of CD14 -159C/T polymorphism did not confer risk for GC (in our study: [P=0.93]; in the meta-analysis: T vs 2N odds ratio =1.28 and 95% confidence interval (CI) =0.95-1.24, [P=0.24]). However, we found a significant association in the recessive model (in our study: TT vs TC+CC [P=0.04]; in the meta-analysis: TT vs TC+CC odds ratio =1.12 and 95% CI =1.01-1.26, [P=0.04]). Furthermore, a subgroup analysis by ethnicity showed that TT genotype was significantly associated with GC in Asian (odds ratio =1.17 and 95% CI =1.02-1.34, [P=0.02]) but not in Caucasian.

CONCLUSION

Our results highlight the TT genotype of CD14 -159C/T as a genetic susceptibility factor for gastric cancer, particularly, in Asians and population-based controls.

Investigating the Role of TNF-α and IFN-γ Activation on the Dynamics of iNOS Gene Expression in LPS Stimulated Macrophages

Macrophage produced inducible nitric oxide synthase (iNOS) is known to play a critical role in the proinflammatory response against intracellular pathogens by promoting the generation of bactericidal reactive nitrogen species. Robust and timely production of nitric oxide (NO) by iNOS and analogous production of reactive oxygen species are critical components of an effective immune response. In addition to pathogen associated lipopolysaccharides (LPS), iNOS gene expression is dependent on numerous proinflammatory cytokines in the cellular microenvironment of the macrophage, two of which include interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α). To understand the synergistic effect of IFN-γ and TNF-α activation, and LPS stimulation on iNOS expression dynamics and NO production, we developed a systems biology based mathematical model. Using our model, we investigated the impact of pre-infection cytokine exposure, or priming, on the system. We explored the essentiality of IFN-γ priming to the robustness of initial proinflammatory response with respect to the ability of macrophages to produce reactive species needed for pathogen clearance. Results from our theoretical studies indicated that IFN-γ and subsequent activation of IRF1 are essential in consequential production of iNOS upon LPS stimulation. We showed that IFN-γ priming at low concentrations greatly increases the effector response of macrophages against intracellular pathogens. Ultimately the model demonstrated that although TNF-α contributed towards a more rapid response time, measured as time to reach maximum iNOS production, IFN-γ stimulation was significantly more significant in terms of the maximum expression of iNOS and the concentration of NO produced.

The intracerebroventricular injection of rimonabant inhibits systemic lipopolysaccharide-induced lung inflammation

We investigated the role of intracerebroventricular (ICV) injection of rimonabant (500ng), a CB1 antagonist, on lipopolysaccharide ((LPS) 5mg/kg)-induced pulmonary inflammation in rats in an isolated perfused lung model. There were decreases in pulmonary capillary pressure (Ppc) and increases in the ((Wet-Dry)/Dry lung weight)/(Ppc) ratio in the ICV-vehicle/LPS group at 4h. There were decreases in TLR4 pathway markers, such as interleukin receptor-associated kinase-1, IκBα, Raf1 and phospho-SFK (Tyr416) at 30min and at 4h increases in IL-6, vascular cell adhesion molecule-1 and myeloperoxidase in lung homogenate. Intracerebroventricular rimonabant attenuated these LPS-induced responses, indicating that ICV rimonabant modulates LPS-initiated pulmonary inflammation.

Novel inflammatory biomarkers in primary hyperparathyroidism

OBJECTIVE

Primary hyperparathyroidism (PHPT) has been associated with low-grade inflammation and increased risk of cardiovascular disease (CVD). The aim of the study was to investigate systemic levels of pro-inflammatory proteins that previously have not been examined in patients with PHPT. The selection of the pro-inflammatory biomarkers included in this study, MMP9, S100A4, S100A8/A9 and the receptors sCD14 and RAGE, was based on a previous microarray screen of mRNAs in adipose tissue from PHPT patients.

DESIGN

A prospective study was conducted on a total of 57 patients with PHPT and a control group of 20 healthy blood donors.

METHODS

PHPT patients with normalisation of serum calcium levels after parathyroidectomy were followed for 6 months. Forty-two patients participated in the longitudinal study, in which blood samples were taken at inclusion, and 1, 3 and 6 months after surgery.

RESULTS

We observed increased serum levels of MMP9 (P=0.029), S100A4 (P<0.001) and sCD14 (P=0.002) in the 57 patients with PHPT compared to the control-group. During 6 months of follow up, S100A4 (P=0.022) and sCD14 (0.002) decreased significantly, while serum levels of MMP9 increased (P=0.025).

CONCLUSIONS

The results demonstrate an increased inflammatory response in PHPT patients shown by elevated MMP9, S100A4 and sCD14 at inclusion. During the 6 months of follow-up, MMP9 increased further, possibly due to the tissue repair process after parathyroidectomy. S100A4 and sCD14 decreased after surgery demonstrating a partial reversal of the systemic inflammation.

Transforming growth factor-β-activated kinase 1 resistance limits glucocorticoid responsiveness to Toll-like receptor 4-mediated inflammation

Glucocorticoids (GC) are among the most effective anti-inflammatory drugs, but are often associated with serious adverse effects or inadequate therapeutic responses. Here, we use activation of different Toll-like receptors (TLRs) by their respective ligands to evaluate context-specific GC sensitivity in the macrophage. Recruitment and activation of transforming growth factor-β-activated kinase 1 (TAK1), downstream of TLR engagement, is crucial in activating multiple inflammatory pathways, and contributes to inflammatory disorders. We hypothesize that GC exert anti-inflammatory effects through regulation of TAK1. Both in vivo and in vitro, in comparison to other TLRs, there was limited GC potency in restricting TLR4 ligand-mediated secretion of interleukin-6, tumour necrosis factor-α and interleukin-12. Also, we found that inactivation of TAK1 both in vivo and in vitro strongly inhibits TLR4-induced inflammation-associated genes beyond the suppressive effects from GC treatment. However, there was no effect of TAK1 inactivation on GC inhibition of TLR3- or TLR9-initiated inflammatory actions. Together, our findings demonstrate that GC resistance for TAK1 activation associated with TLR4 engagement may be an important contributor to GC resistance in inflammatory disorders.

Fasting glucose level modulates cell surface expression of CD11b and CD66b in granulocytes and monocytes of patients with type 2 diabetes

INTRODUCTION

Cardiovascular complications are the leading cause of mortality in type 2 diabetes (T2DM), in which onset and progression of atherosclerosis is linked to chronic inflammation. Activation status of innate immune cells (granulocytes [Gc], monocytes [Mc]), as reflected by increased CD11b, CD66b, and other surface markers, increases their endothelial and cytokines/chemokines release. Whereas this inflammatory activation seems inversely related to poor glycemic control, the effect of acute spontaneous hyperglycemia on innate immune cell activation remains unclear.

METHODS

Expression of key markers (CD11b, CD14, CD16, CD62L, and CD66b) was therefore determined by flow cytometry on whole blood of healthy subjects and patients with T2DM with spontaneous fasting euglycemia or hyperglycemia both at baseline and after 30, 90, and 240 minutes of incubation at room temperature.

RESULTS

Hyperglycemic patients with T2DM had significantly higher Gc and Mc CD11b and Gc CD66b surface mean fluorescence intensity compared with the euglycemic patients with T2DM whose values were similar to those of the healthy controls. CD16 expression in CD14+CD16+ Mc was elevated in all patients with T2DM, regardless of glycemic levels.

CONCLUSION

Our data suggest that whereas the presence of diabetes per se may have a proinflammatory effect, hyperglycemia seems to further acutely exacerbate innate cell inflammatory status and their consequent endothelial adhesion and vascular damage potential.

Soluble CD14 is independently associated with coronary calcification and extent of subclinical vascular disease in treated HIV infection

OBJECTIVE

To use multimodality imaging to explore the relationship of biomarkers of inflammation, T-cell activation and monocyte activation with coronary calcification and subclinical vascular disease in a population of HIV-infected patients on antiretroviral therapy (ART).

DESIGN

Cross-sectional.

METHODS

A panel of soluble and cellular biomarkers of inflammation and immune activation was measured in 147 HIV-infected adults on ART with HIV RNA less than 1000 copies/ml and low-density lipoprotein cholesterol (LDL-C) 130  mg/dl or less. We examined the relationship of biomarkers to coronary calcium (CAC) score and multiple ultrasound measures of subclinical vascular disease.

RESULTS

Overall, median (interquartile range, IQR) age was 46 (40-53) years; three-quarters of participants were male and two-thirds African-American. Median 10-year Framingham risk score was 6%. Participants with CAC more than 0 were older, less likely to be African-American and had higher current and lower nadir CD4 T-cell counts. Most biomarkers were similar between those with and without CAC; however, soluble CD14 was independently associated with CAC after adjustment for traditional risk factors. Among those with a CAC score of zero, T-cell activation and systemic inflammation correlated with carotid intima-media thickness and brachial hyperemic velocity, respectively. Compared with normal participants and those with CAC only, participants with increasing degrees of subclinical vascular disease had higher levels of sCD14, hs-CRP and fibrinogen (all P<0.05).

CONCLUSION

Soluble CD14 is independently associated with coronary artery calcification, and, among those with detectable calcium, predicts the extent of subclinical disease in other vascular beds. Future studies should investigate the utility of multimodality imaging to characterize vascular disease phenotypes in this population.

CD14 gene variants and their importance for childhood croup, atopy, and asthma

BACKGROUND

The CD14 gene has an important role in the detection of inflammatory provoking pathogens and in the ensuing signaling of the innate immune response. We assessed the role of CD14 C-159T, G-1359T in the expression of asthma, croup, and allergy in Canadian school children of ages 6 to 14 years.

METHODS

Children attending schools in a rural community participated in a cross-sectional survey of respiratory health. Following consent, we conducted clinical assessments to collect buccal swabs for genotyping and perform skin prick testing (SPT) to determine atopic status. Genotyping and SPT results were available for 533 and 499 children, respectively. Separate multivariable analyses that included both polymorphisms were conducted for each phenotype.

RESULTS

The prevalence of asthma, allergy, and croup was 18.6%, 22.4%, and 6.6%, respectively. Children with the T/T variant of CD14 G-1359T were more likely to have physician diagnosed asthma (26.8%). Children with C/C variant of CD14 C-159T had a significantly lower prevalence of croup (2.6%). Haplotype analyses of the two CD14 polymorphisms showed that individuals with the T|T haplotype combination were significantly more likely to have asthma (P = 0.014).

CONCLUSIONS

In this study, CD14 variants are important for the expression of croup and asthma but not atopy.

Fasting glucose level modulates cell surface expression of CD11b and CD66b in granulocytes and monocytes of patients with type 2 diabetes

INTRODUCTION

Cardiovascular complications are the leading cause of mortality in type 2 diabetes (T2DM), in which onset and progression of atherosclerosis is linked to chronic inflammation. Activation status of innate immune cells (granulocytes [Gc], monocytes [Mc]), as reflected by increased CD11b, CD66b, and other surface markers, increases their endothelial and cytokines/chemokines release. Whereas this inflammatory activation seems inversely related to poor glycemic control, the effect of acute spontaneous hyperglycemia on innate immune cell activation remains unclear.

METHODS

Expression of key markers (CD11b, CD14, CD16, CD62L, and CD66b) was therefore determined by flow cytometry on whole blood of healthy subjects and patients with T2DM with spontaneous fasting euglycemia or hyperglycemia both at baseline and after 30, 90, and 240 minutes of incubation at room temperature.

RESULTS

Hyperglycemic patients with T2DM had significantly higher Gc and Mc CD11b and Gc CD66b surface mean fluorescence intensity compared with the euglycemic patients with T2DM whose values were similar to those of the healthy controls. CD16 expression in CD14+CD16+ Mc was elevated in all patients with T2DM, regardless of glycemic levels.

CONCLUSION

Our data suggest that whereas the presence of diabetes per se may have a proinflammatory effect, hyperglycemia seems to further acutely exacerbate innate cell inflammatory status and their consequent endothelial adhesion and vascular damage potential.

CD14 directs adventitial macrophage precursor recruitment: role in early abdominal aortic aneurysm formation

Background

Recruitment of macrophage precursors to the adventitia plays a key role in the pathogenesis of abdominal aortic aneurysms (AAAs), but molecular mechanisms remain undefined. The innate immune signaling molecule CD14 was reported to be upregulated in adventitial macrophages in a murine model of AAA and in monocytes cocultured with aortic adventitial fibroblasts (AoAf) in vitro, concurrent with increased interleukin‐6 (IL‐6) expression. We hypothesized that CD14 plays a crucial role in adventitial macrophage precursor recruitment early during AAA formation.

Methods and Results

CD14^−/− mice were resistant to AAA formation induced by 2 different AAA induction models: aortic elastase infusion and systemic angiotensin II (AngII) infusion. CD14 gene deletion led to reduced aortic macrophage infiltration and diminished elastin degradation. Adventitial monocyte binding to AngII‐infused aorta in vitro was dependent on CD14, and incubation of human acute monocytic leukemia cell line‐1 (THP‐1) monocytes with IL‐6 or conditioned medium from perivascular adipose tissue (PVAT) upregulated CD14 expression. Conditioned medium from AoAf and PVAT induced CD14‐dependent monocyte chemotaxis, which was potentiated by IL‐6. CD14 expression in aorta and plasma CD14 levels were increased in AAA patients compared with controls.

Conclusions

These findings link CD14 innate immune signaling via a novel IL‐6 amplification loop to adventitial macrophage precursor recruitment in the pathogenesis of AAA.

Influence of pentraxin 3 (PTX3) genetic variants on myocardial infarction risk and PTX3 plasma levels

PTX3 is a long pentraxin of the innate immune system produced by different cell types (mononuclear phagocytes, dendritic cells, fibroblasts and endothelial cells) at the inflammatory site. It appears to have a cardiovascular protective function by acting on the immune-inflammatory balance in the cardiovascular system. PTX3 plasma concentration is an independent predictor of mortality in patients with acute myocardial infarction (AMI) but the influence of PTX3 genetic variants on PTX3 plasma concentration has been investigated very little and there is no information on the association between PTX3 variations and AMI. Subjects of European origin (3245, 1751 AMI survivors and 1494 controls) were genotyped for three common PTX3 polymorphisms (SNPs) (rs2305619, rs3816527, rs1840680). Genotype and allele frequencies of the three SNPs and the haplotype frequencies were compared for the two groups. None of the genotypes, alleles or haplotypes were significantly associated with the risk of AMI. However, analysis adjusted for age and sex indicated that the three PTX3 SNPs and the corresponding haplotypes were significantly associated with different PTX3 plasma levels. There was also a significant association between PTX3 plasma concentrations and the risk of all-cause mortality at three years in AMI patients (OR 1.10, 95% CI: 1.01–1.20, p = 0.02). Our study showed that PTX3 plasma levels are influenced by three PTX3 polymorphisms. Genetically determined high PTX3 levels do not influence the risk of AMI, suggesting that the PTX3 concentration itself is unlikely to be even a modest causal factor for AMI. Analysis also confirmed that PTX3 is a prognostic marker after AMI.

Therapeutic role of toll-like receptor modification in cardiovascular dysfunction

Toll-like receptors (TLR) are key pattern recognition receptors in the innate immune system. The TLR-mediated immune response against pathogens is usually protective however inappropriate TLR activation may lead to excessive tissue damage. It is well recognised that TLRs respond to a variety of endogenous as well as exogenous ligands. By responding to endogenous ligands that are exposed during cellular damage, TLRs have been implicated in a range of pathological conditions associated with cardiovascular dysfunction. Increasing knowledge on the mechanisms involved in TLR signalling has encouraged the exploration of therapeutic pharmacological modulation of TLR activation in conditions such as atherosclerosis, ischaemic heart disease, heart failure and ischaemic reperfusion injury. The aim of this review is to explore the translational potentials of TLR modification in cardiovascular dysfunction, where these agents have been studied.

Trypsin inhibits lipopolysaccharide signaling in macrophages via toll-like receptor 4 accessory molecules

AIMS

To examine the role of trypsin in the immune response of macrophages and to determine whether protease-activated receptors (PARs) are involved in the effects of trypsin.

MAIN METHODS

We used RAW264.7 cells and peritoneal macrophages isolated from C57BL/6 wild-type mice, PAR2 knockout mice, and ddY mice. Macrophages were stimulated with lipopolysaccharide (LPS) in the presence or absence of trypsin, thrombin, and PAR subtype-specific agonists (PARs-AP). Activation of macrophages was quantified by nitric oxide production and expression of inflammatory mediators, such as inducible nitric oxide synthase, interleukin-1β, and interleukin-6. To clarify the effect of trypsin on LPS receptors, we also investigated the expression of toll-like receptor 4 (TLR4), soluble MD-2 (sMD-2), membrane-bound MD-2 (mMD-2), soluble CD14 (sCD14), and membrane-bound CD14 (mCD14). To directly investigate the effect of trypsin on CD14 protein, we expressed recombinant CD14 protein.

KEY FINDINGS

Trypsin inhibited LPS-induced nitric oxide production and expression of inducible nitric oxide synthase, interleukin-1β, and interleukin-6. The same inhibitory effects of trypsin were observed in wild-type macrophages and in PAR2 knockout macrophages. Furthermore, the other PAR agonists, thrombin, PAR1-AP, PAR2-AP, and PAR4-AP, did not mimic the effect of trypsin. Although trypsin did not affect TLR4 or mMD-2 expression, sCD14, mCD14, and sMD-2 expressions were decreased by trypsin. Furthermore, trypsin also degraded recombinant CD14 protein.

SIGNIFICANCE

Trypsin inhibited LPS signaling PAR-independently via degradation of TLR4 accessory molecules. This observation provides a better understanding of the complicated immune response in acute pancreatitis.

A single nucleotide polymorphism in 3'-untranslated region contributes to the regulation of Toll-like receptor 4 translation

We have previously shown that a single nucleotide polymorphism rs11536889 in the 3'-untranslated region (UTR) of TLR4 was associated with periodontitis. In this study the effects of this single nucleotide polymorphism on Toll-like receptor (TLR) 4 expression were investigated. Monocytes from subjects with the C/C genotype expressed higher levels of TLR4 on their surfaces than those from subjects with the other genotypes. Peripheral blood mononuclear cells (PBMCs) from the C/C and G/C subjects secreted higher levels of IL-8 in response to lipopolysaccharide (LPS), a TLR4 ligand, than the cells from the G/G subjects. However, there was no significant difference in TLR4 mRNA levels in PBMCs from the subjects with each genotype. After stimulation with tripalmitoylated CSK(4) (Pam(3)CSK(4)), TLR4 mRNA levels increased in PBMCs from both the C/C and G/G subjects, whereas TLR4 protein levels increased in PBMCs from the C/C but not G/G subjects. Transient transfection of a series of chimeric luciferase constructs revealed that a fragment of 3'-UTR containing rs11536889 G allele, but not C allele, suppressed luciferase activity induced by LPS or IL-6. Two microRNAs, hsa-miR-1236 and hsa-miR-642a, were predicted to bind to rs11536889 G allele. Inhibition of these microRNAs reversed the suppressed luciferase activity. These microRNA inhibitors also up-regulated endogenous TLR4 protein on THP-1 cells (the G/G genotype) after LPS stimulation. Furthermore, mutant microRNAs that bind to the C allele inhibited the luciferase activity of the construct containing the C allele. These results indicate that genetic variation of rs11536889 contributes to translational regulation of TLR4, possibly by binding to microRNAs.

Ehrlichia chaffeensis TRP32 interacts with host cell targets that influence intracellular survival

Ehrlichia chaffeensis is an obligately intracellular bacterium that exhibits tropism for mononuclear phagocytes and survives by evading host cell defense mechanisms. Recently, molecular interactions of E. chaffeensis tandem repeat proteins 47 and 120 (TRP47 and -120) and the eukaryotic host cell have been described. In this investigation, yeast two-hybrid analysis demonstrated that an E. chaffeensis type 1 secretion system substrate, TRP32, interacts with a diverse group of human proteins associated with major biological processes of the host cell, including protein synthesis, trafficking, degradation, immune signaling, cell signaling, iron metabolism, and apoptosis. Eight target proteins, including translation elongation factor 1 alpha 1 (EF1A1), deleted in azoospermia (DAZ)-associated protein 2 (DAZAP2), ferritin light polypeptide (FTL), CD63, CD14, proteasome subunit beta type 1 (PSMB1), ring finger and CCCH-type domain 1 (RC3H1), and tumor protein p53-inducible protein 11 (TP53I11) interacted with TRP32 as determined by coimmunoprecipitation assays, colocalization with TRP32 in HeLa and THP-1 cells, and/or RNA interference. Interactions between TRP32 and host targets localized to the E. chaffeensis morulae or in the host cell cytoplasm adjacent to morulae. Common or closely related interacting partners of E. chaffeensis TRP32, TRP47, and TRP120 demonstrate a molecular convergence on common cellular processes and molecular cross talk between Ehrlichia TRPs and host targets. These findings further support the role of TRPs as effectors that promote intracellular survival.

Immunogenetics of ageing

The ageing process is very complex. Human longevity is a multifactorial trait which is determined by genetic and environmental factors. Twin and family studies imply that up to 25% of human lifespan is heritable. The longevity gene candidates have generally fallen into the following categories: inflammatory and immune-related factors, stress response elements, mediators of glucose and lipid metabolism, components of DNA repair and cellular proliferation and mitochondrial DNA haplogroups. Because of the central role of HLA molecules in the development of protective immunity and the extraordinary degree of polymorphism of HLA genes, many studies have addressed the possible impact of these genes on human longevity. Most of the data available so far demonstrated a possible role of HLA class II specificities in human longevity but definitive evidence has remained elusive. Although the data are limited and controversial, it has been hypothesized that longevity could be associated with cytokine gene polymorphisms correlating with different levels of cytokine production, thereby modulating immune responses in health and disease. Because of the essential role of cytokines in immune responses, the regulation of cytokine gene expression and their polymorphic nature, the genetic variations of these loci with functional significance could be appropriate immunogenetic candidate markers implicated in the mechanism of successful ageing and longevity. In addition, several other genes such as Toll-like receptor genes, Cycloxygenases (COX)/Lipoxygenases (LOX), CCR5, NK receptor genes and MBL2 have been assessed as a possible biomarkers associated with ageing. This review will summarize the data on the role of these immune genes in human longevity.

Genetic analysis in cardiovascular disease: a clinical perspective

Many forms of cardiovascular disease (CVD) demonstrate heritability and thus a genetic contribution is likely. This is most evident when considering the "simple" Mendelian traits such as hypertrophic cardiomyopathy. However, family history also influences our assessment of patients with complex traits such as coronary artery disease, hypertension, and common forms of hypercholesterolemia, as observed in clinical practice. Recent research has led to advances in our understanding of the genetic basis of both the simple and complex forms of CVD. This review presents the current state of knowledge regarding major gene disorders, as well as more common, complex forms of CVD such as coronary artery disease. It discusses the fundamental approaches being used to identify the genetic basis of the various disease states, as well as the practical implications of the discoveries to clinicians. It also focuses on our need to assess the extent by which genetic analysis can alter our calculation of an individual's risk of disease, and our ability to successfully target treatment that will modify this process.

Gut microbiota, lipopolysaccharides, and innate immunity in the pathogenesis of obesity and cardiovascular risk

Compelling evidence supports the concepts that gut microbiota actively promotes weight gain and fat accumulation and sustains, indirectly, a condition of low-grade inflammation, thus enhancing the cardiovascular risk. Fewer Bacteroidetes and more Firmicutes seem to characterize the gut microbiota of obese people as compared with that of lean individuals. This difference translates into an increased efficiency of microbiota of obese individuals in harvesting energy from otherwise indigestible carbohydrates. Furthermore, the microbiota also seems able to favor fat accumulation. Indeed, studies performed in germ-free animals have demonstrated that conventionalization of sterile intestine with gut microbiota is associated with an enhanced expression of various lipogenic genes in different tissues, i.e., hepatic, adipose, and muscle tissues. Finally, the microbiota favors systemic exposure to the lipopolysaccharides (LPSs), large glycolipids derived from the outer membrane of Gram-negative bacteria. LPSs can cause a condition of "metabolic endotoxemia" characterized by low-grade inflammation, insulin resistance, and augmented cardiovascular risk. LPSs are a powerful trigger for the innate immune system response. Upon binding to the Toll-like receptor 4 and its coreceptors, LPSs trigger a cascade of responses ultimately resulting in the release of proinflammatory molecules that interfere with modulation of glucose and insulin metabolism, promote development and rupture of the atherosclerotic plaque, and favor progression of fatty liver disease to steatohepatitis. This review gives a comprehensive breakdown of the interaction among gut microbiota, LPSs, and the innate immune system in the development of obesity and promotion of an individual's cardiovascular risk.

Genomic approaches to coronary artery disease

Coronary artery disease (CAD) is a leading cause of death and disability worldwide. In addition to lifestyle and environmental factors which are major aetiologic determinants, there is considerable familial clustering of the disease indicating a genetic component in its causation. Although the total genetic contribution to CAD risk can be quantified, the determination of the size and number of contributing effects is impossible without identifying all CAD susceptibility genes. However, despite extensive studies, strong evidence of a molecular genetic association with coronary artery disease or myocardial infarction remains elusive. Genome wide association studies have been successful in identifying robust associations of single nucleotide polymorphisms (SNP) with CAD. Identifying the causal variant and dissecting pathways linking these variants to disease process is a major challenge. Technologies from whole genome sequencing, proteomics, transcriptomics and metabolomics are now available to extend analysis to a more complete range of potential susceptibility variants, and to support more explicit modelling of the joint effects of genes and environment. The availability of these high throughput technologies does not diminish the importance of rigorous phenotyping and appropriate study designs in all the endeavours to understand the aetiopathogenesis of CAD. Combining classical epidemiology with modern genomics will require collaborative efforts within the cardiovascular disease community at both bench and bedside and this will have the potential to expand our understanding of CAD and translate discoveries into clinically useful applications that will have a major impact on public health.

Translational systems approaches to the biology of inflammation and healing

Inflammation is a complex, non-linear process central to many of the diseases that affect both developed and emerging nations. A systems-based understanding of inflammation, coupled to translational applications, is therefore necessary for efficient development of drugs and devices, for streamlining analyses at the level of populations, and for the implementation of personalized medicine. We have carried out an iterative and ongoing program of literature analysis, generation of prospective data, data analysis, and computational modeling in various experimental and clinical inflammatory disease settings. These simulations have been used to gain basic insights into the inflammatory response under baseline, gene-knockout, and drug-treated experimental animals for in silico studies associated with the clinical settings of sepsis, trauma, acute liver failure, and wound healing to create patient-specific simulations in polytrauma, traumatic brain injury, and vocal fold inflammation; and to gain insight into host-pathogen interactions in malaria, necrotizing enterocolitis, and sepsis. These simulations have converged with other systems biology approaches (e.g., functional genomics) to aid in the design of new drugs or devices geared towards modulating inflammation. Since they include both circulating and tissue-level inflammatory mediators, these simulations transcend typical cytokine networks by associating inflammatory processes with tissue/organ impacts via tissue damage/dysfunction. This framework has now allowed us to suggest how to modulate acute inflammation in a rational, individually optimized fashion. This plethora of computational and intertwined experimental/engineering approaches is the cornerstone of Translational Systems Biology approaches for inflammatory diseases.

CD14 polymorphisms and serum CD14 levels through childhood: a role for gene methylation?

BACKGROUND

CD14 is a pattern-recognition receptor for environmental LPS, and engagement of the CD14-LPS complex activates innate host defense mechanisms. Single nucleotide polymorphisms (SNPs) in the CD14 gene have been associated with soluble CD14 (sCD14) levels, but inconsistencies between studies suggest the presence of regulatory mechanisms hitherto not well understood.

OBJECTIVE

We sought to investigate possible associations between CD14 SNPs and sCD14 levels at different time points in childhood (at birth [cord blood] and 2 and 10 years) and to explore whether these associations were related to CD14 gene methylation.

METHODS

Four SNPs, rs2569191 (-1145GA), rs5744455 (-550CT or -651CT), rs2569190 (-159CT or -260CT), and rs4914 in CD14 were genotyped in 762 children from the Environmental and Childhood Asthma study. Genotype frequencies were analyzed for association with sCD14 levels in 660 babies, 346 children at age 2 years, and 360 children at age 10 years. In a subgroup of 157 children with DNA available at both 2 and 10 years of age, CD14 methylation patterns were determined and analyzed against detected CD14 gene-sCD14 associations.

RESULTS

rs2569191, rs5744455, and rs2569190 were associated with sCD14 levels at birth and 2 years, but only rs5744455 was associated with sCD14 levels at 10 years. CD14 methylation increased significantly from age 2 to 10 years, and the level of methylation was inversely correlated with sCD14 levels at 10 years.

CONCLUSION

The reduced effect of CD14 polymorphisms on sCD14 levels from early to late childhood paralleled a small but significant increase in CD14 methylation during the same period.

Impact of polymorphisms of TLR4/CD14 and TLR3 on acute rejection in kidney transplantation

BACKGROUND

Organ transplantation itself inevitably activates the innate immune system by toll-like receptors (TLRs), potentially leading to allograft rejection and graft failure. We evaluated the possible association between the TLR4/CD14 and TLR3 polymorphisms of donor-recipient pairs, and acute rejection after living donor kidney transplantation.

METHODS

TLR4 -1607T/C (rs10759932), -2026A/G (rs1927914); CD14 -159C/T (rs2569190); and TLR3 rs3775290, rs3775291, and rs3775296 were genotyped using DNA samples from 216 donor-recipient pairs of adult living donor kidney transplantation between January 1996 and July 2006. Dual luciferase reporter assay was performed to determine the functional significance of promoter single-nucleotide polymorphisms (SNPs) of TLR4.

RESULTS

Acute rejection occurred in 42 recipients (19.4%) of 216 adult transplant patients within 1 year. The genotype distributions of both recipient and donor TLR4 rs10759932 differed significantly between the control (no rejection) and acute rejection groups. For recipient rs10759932, the adjusted odds ratio for the TC+CC over TT genotype was 0.25 (95% confidence interval, 0.11-0.57; P =0.001). When the rs10759932 CC genotype was present in the recipient or donor, no episode of acute rejection occurred (Fisher's exact test, P =0.023). The presence of the rs10759932 C allele was associated with higher rejection-free survival rates (log-rank test, P =0.0053). However, there was no difference in transcriptional activity between wild-type and variant promoters of TLR4. In contrast to TLR4, SNPs of TLR3 or CD14 had no influence on acute rejection.

CONCLUSION

These findings suggest the importance of TLR4 in the pathogenesis of acute rejection in kidney transplantation.

CD14 C260T promoter polymorphism and the risk of cerebrovascular diseases: a meta-analysis

Cerebrovascular diseases (CVD) are dysfunctions of the brain, resulting from diseases of blood vessels supplying the brain. Atherosclerosis is one of the major underlying causes of CVD, in which inflammation plays a crucial role. One of the inflammatory mechanisms contributing to atherogenesis is the activation of monocytes and macrophages, which could be mediated by the bacterial endotoxin lipopolysaccharide (LPS) via its receptor CD14. The C260T (rs2569190) single-nucleotide polymorphism (SNP) in the promoter region of the CD14 gene was implicated in CVD. To assess the role of this SNP in CVD, a comprehensive meta-analysis of the available genetic data was conducted. All the case-control association studies evaluating the role of CD14 C260T in CVD were identified. Of these, 7 studies (comprising a total of 1488 patients and 1600 control subjects) were included in this meta-analysis. To measure the strength of genetic association for the gene variant, the odds ratios (ORs) were calculated using both fixed and random effects for comparisons of the alleles, the genotypes, and the dominant and recessive genotype models. The results showed there was no significant association between the T allele of C260T and the risk of CVD under the fixed effects model, OR = 0.99 (95% CI (0.89, 1.09)), P = 0.84; or the random effects model, OR = 0.99 (95% CI (0.88, 1.11)), P = 0.83. Similar results were obtained for the homozygotes and the dominant and recessive models. In conclusion, the results of this meta-analysis suggest the CD14 C260T polymorphism is not a risk factor for CVD. However, more studies in ethnically varied populations are needed to evaluate in a reliable manner the role of this SNP in CVD susceptibility.