Human CC chemokine liver-expressed chemokine/CCL16 is a functional ligand for CCR1, CCR2 and CCR5, and constitutively expressed by hepatocytes

FibroScan® versus Biochemical Scores: A Study of Liver Fibrosis in HIV with HBV Co-Infection

The study aimed to determine liver fibrosis in human immunodeficiency virus (HIV) positive individuals using transient elastography (FibroScan®), Fibrosis-4 (FIB-4) score, and aspartate aminotransferase (AST) to Platelet Ratio Index (APRI) in the HIV Department from Infectious Diseases Hospital "Victor Babeș" Craiova, Romania. Of the analyzed HIV-positive subjects (n = 161), 93 (57.76%) had HIV mono-infection, and 68 (42.24%) had Hepatitis B Virus (HBV) co-infection. The prevalence of advanced liver fibrosis was higher (F2: 11.76% and F3: 13.24%, F4: 4.41%) in the HIV-HBV co-infected group compared to the HIV mono-infected group. The univariate and multivariate analysis identified HBV co-infection (OR = 5.73) male sex (OR = 5.34), serum aspartate amino-transferase levels (Pearson's rho = 0.273), low platelet count (Pearson's rho = -0.149) and erythrocyte sedimentation rate (OR = 1.030) as risk factors for the presence of liver fibrosis. Body mass index (OR = 1.08), serum lipid levels (OR = 0.96), viral load at diagnosis (OR = 1.00005), and low CD4+ cell count (OR = 0.977) were also correlated with liver fibrosis. The FIB-4 and APRI scores were strongly correlated with each other. In conclusion, HBV co-infection seems to be a determinant factor for liver fibrosis development in people living with HIV, together with other risk factors.

Characterizing ligand-receptor interactions and unveiling the pro-tumorigenic role of CCL16-CCR1 axis in the microenvironment of hepatocellular carcinoma

Background

The heterogeneity of the tumor microenvironment significantly influences the prognosis of hepatocellular carcinoma (HCC) patients, with cell communication through ligand-receptor complexes playing a central role.

Methods

We conducted single-cell transcriptomic analysis on ten HCC tissues to identify ligand-receptor genes involved in malignant HCC cell communication using CellChat. Leveraging RNA-Seq data from the TCGA Liver Cancer (TCGA-LIHC) and Liver Cancer - RIKEN, JP (LIRI-JP) cohorts, we employed Cox regression analysis to screen for prognosis-related genes. Prognostic risk models were constructed through unsupervised clustering and differential gene expression analysis. Subsequently, a co-culture system involving tumor cells and macrophages was established. A series of experiments, including Transwell assays, immunofluorescence staining, immunoprecipitation, flow cytometry, and immunohistochemistry, were conducted to elucidate the mechanism through which HCC cells recruit macrophages via the CCL16-CCR1 axis.

Results

Single-cell analysis unveiled significant interactions between malignant HCC cells and macrophages, identifying 76 related ligand-receptor genes. Patients were classified into three subtypes based on the expression patterns of eight prognosis-related ligand-receptor genes. The subtype with the worst prognosis exhibited reduced infiltration of T cell-related immune cells, downregulation of immune checkpoint genes, and increased M2-like tumor-associated macrophage scores. In vitro experiments confirmed the pivotal role of the CCL16-CCR1 axis in the recruitment and M2 polarization of tumor-associated macrophages. Clinical samples demonstrated a significant association between CCL16 protein expression levels and advanced stage, lymph node metastasis, and distant metastasis. Immunohistochemistry and immunofluorescence staining further confirmed the correlation between CCL16 and CCR1, CD68, and CD206, as well as CD68+CCR1+ macrophage infiltration.

Conclusions

Our study identified molecular subtypes, a prognostic model, and immune microenvironment features based on ligand-receptor interactions in malignant HCC cell communication. Moreover, we revealed the pro-tumorigenic role of HCC cells in recruiting M2-like tumor-associated macrophages through the CCL16-CCR1 axis.

The Role and Therapeutic Targeting of CCR5 in Breast Cancer

The G-protein-coupled receptor C-C chemokine receptor 5 (CCR5) functions as a co-receptor for the entry of HIV into immune cells. CCR5 binds promiscuously to a diverse array of ligands initiating cell signaling that includes guided migration. Although well known to be expressed on immune cells, recent studies have shown the induction of CCR5 on the surface of breast cancer epithelial cells. The function of CCR5 on breast cancer epithelial cells includes the induction of aberrant cell survival signaling and tropism towards chemo attractants. As CCR5 is not expressed on normal epithelium, the receptor provides a potential useful target for therapy. Inhibitors of CCR5 (CCR5i), either small molecules (maraviroc, vicriviroc) or humanized monoclonal antibodies (leronlimab) have shown anti-tumor and anti-metastatic properties in preclinical studies. In early clinical studies, reviewed herein, CCR5i have shown promising results and evidence for effects on both the tumor and the anti-tumor immune response. Current clinical studies have therefore included combination therapy approaches with checkpoint inhibitors.

Identification of serum biomarkers for necrotizing enterocolitis using aptamer-based proteomics

Introduction

Necrotizing enterocolitis (NEC) is a potentially fatal intestinal disease primarily affecting preterm infants. Early diagnosis of neonates with NEC is crucial to improving outcomes; however, traditional diagnostic tools remain inadequate. Biomarkers represent an opportunity to improve the speed and accuracy of diagnosis, but they are not routinely used in clinical practice.

Methods

In this study, we utilized an aptamer-based proteomic discovery assay to identify new serum biomarkers of NEC. We compared levels of serum proteins in neonates with and without NEC and identified ten differentially expressed serum proteins between these groups.

Results

We detected two proteins, C-C motif chemokine ligand 16 (CCL16) and immunoglobulin heavy constant alpha 1 and 2 heterodimer (IGHA1 IGHA2), that were significantly increased during NEC and eight that were significantly decreased. Generation of receiver operating characteristic (ROC) curves revealed that alpha-fetoprotein (AUC = 0.926), glucagon (AUC = 0.860), and IGHA1 IGHA2 (AUC = 0.826) were the proteins that best differentiated patients with and without NEC.

Discussion

These findings indicate that further investigation into these serum proteins as a biomarker for NEC is warranted. In the future, laboratory tests incorporating these differentially expressed proteins may improve the ability of clinicians to diagnose infants with NEC rapidly and accurately.

A Pathogenic Role of Non-Parenchymal Liver Cells in Alcohol-Associated Liver Disease of Infectious and Non-Infectious Origin

Now, much is known regarding the impact of chronic and heavy alcohol consumption on the disruption of physiological liver functions and the induction of structural distortions in the hepatic tissues in alcohol-associated liver disease (ALD). This review deliberates the effects of alcohol on the activity and properties of liver non-parenchymal cells (NPCs), which are either residential or infiltrated into the liver from the general circulation. NPCs play a pivotal role in the regulation of organ inflammation and fibrosis, both in the context of hepatotropic infections and in non-infectious settings. Here, we overview how NPC functions in ALD are regulated by second hits, such as gender and the exposure to bacterial or viral infections. As an example of the virus-mediated trigger of liver injury, we focused on HIV infections potentiated by alcohol exposure, since this combination was only limitedly studied in relation to the role of hepatic stellate cells (HSCs) in the development of liver fibrosis. The review specifically focusses on liver macrophages, HSC, and T-lymphocytes and their regulation of ALD pathogenesis and outcomes. It also illustrates the activation of NPCs by the engulfment of apoptotic bodies, a frequent event observed when hepatocytes are exposed to ethanol metabolites and infections. As an example of such a double-hit-induced apoptotic hepatocyte death, we deliberate on the hepatotoxic accumulation of HIV proteins, which in combination with ethanol metabolites, causes intensive hepatic cell death and pro-fibrotic activation of HSCs engulfing these HIV- and malondialdehyde-expressing apoptotic hepatocytes.

The Increase in Circulating Levels of Pro-Inflammatory Chemokines, Cytokines, and Complement C5 in Canines with Impaired Kidney Function

Chronic low-grade inflammation is a key contributor to the progression of kidney disease. The release of cytokines and other pro-inflammatory proteins may further contribute to detrimental kidney health by increasing interstitial edema and renal fibrosis. The aim of the present study was to investigate the inflammatory markers in canines who developed renal disease naturally and were diagnosed with renal disease either during life or following necropsy, as assessed by a veterinarian. RNA was isolated from canine blood obtained at necropsy and stored as bioarchived samples from ten canines with renal disease (9.6−14.7 yr) and ten controls (10.1−14.8 yr). At the time of death, the mean blood creatinine concentration and BUN were elevated in dogs with renal disease compared to control (both p < 0.01). Samples were assessed for changes in gene expression using the Canine cytokine RT2 Profiler PCR Array for inflammation. There was a significant increase in C-C Motif Chemokine Ligand 16 (CCL16), C-X-C Motif Chemokine Ligand 5 (CXCL5), Interleukin 16 (IL-16), and Complement Component 5 (C5) (all p < 0.05 vs. con). In addition, there was also a statistically non-significant increase in 49 genes and a down-regulation in 35 genes from a panel of total 84 genes. Pro-inflammatory genes including CCL16, CXCL5, IL-16, and C5 can all contribute to renal inflammation and fibrosis through different signaling pathways and may lead to a progressive impairment of kidney function. Blockade of their activation may be important in ameliorating the initiation and/or the progression of renal disease.

Identification of a conserved chemokine receptor motif that enables ligand discrimination

Extensive ligand-receptor promiscuity in the chemokine signaling system balances beneficial redundancy and specificity. However, this feature poses a major challenge to selectively modulate the system pharmacologically. Here, we identified a conserved cluster of three aromatic receptor residues that anchors the second extracellular loop (ECL2) to the top of receptor transmembrane helices (TM) 4 and 5 and enables recognition of both shared and specific characteristics of interacting chemokines. This cluster was essential for the activation of several chemokine receptors. Furthermore, characteristic motifs of the ß₁ strand and 30s loop make the two main CC-chemokine subgroups-the macrophage inflammatory proteins (MIPs) and monocyte chemoattractant proteins (MCPs)-differentially dependent on this cluster in the promiscuous receptors CCR1, CCR2, and CCR5. The cluster additionally enabled CCR1 and CCR5 to discriminate between closely related MIPs based on the N terminus of the chemokine. G protein signaling and β-arrestin2 recruitment assays confirmed the importance of the conserved cluster in receptor discrimination of chemokine ligands. This extracellular site may facilitate the development of chemokine-related therapeutics.

Functional Roles of Chemokine Receptor CCR2 and Its Ligands in Liver Disease

Chemokines are a family of cytokines that orchestrate the migration and positioning of immune cells within tissues and are critical for the function of the immune system. CCR2 participates in liver pathology, including acute liver injury, chronic hepatitis, fibrosis/cirrhosis, and tumor progression, by mediating the recruitment of immune cells to inflammation and tumor sites. Although a variety of chemokines have been well studied in various diseases, there is no comprehensive review presenting the roles of all known chemokine ligands of CCR2 (CCL2, CCL7, CCL8, CCL12, CCL13, CCL16, and PSMP) in liver disease, and this review aims to fill this gap. The introduction of each chemokine includes its discovery, its corresponding chemotactic receptors, physiological functions and roles in inflammation and tumors, and its impact on different immune cell subgroups.

Targeting the CCL2/CCR2 Axis in Cancer Immunotherapy: One Stone, Three Birds?

CCR2 is predominantly expressed by monocytes/macrophages with strong proinflammatory functions, prompting the development of CCR2 antagonists to dampen unwanted immune responses in inflammatory and autoimmune diseases. Paradoxically, CCR2-expressing monocytes/macrophages, particularly in tumor microenvironments, can be strongly immunosuppressive. Thus, targeting the recruitment of immunosuppressive monocytes/macrophages to tumors by CCR2 antagonism has recently been investigated as a strategy to modify the tumor microenvironment and enhance anti-tumor immunity. We present here that beneficial effects of CCR2 antagonism in the tumor setting extend beyond blocking chemotaxis of suppressive myeloid cells. Signaling within the CCL2/CCR2 axis shows underappreciated effects on myeloid cell survival and function polarization. Apart from myeloid cells, T cells are also known to express CCR2. Nevertheless, tissue homing of Treg cells among T cell populations is preferentially affected by CCR2 deficiency. Further, CCR2 signaling also directly enhances Treg functional potency. Thus, although Tregs are not the sole type of T cells expressing CCR2, the net outcome of CCR2 antagonism in T cells favors the anti-tumor arm of immune responses. Finally, the CCL2/CCR2 axis directly contributes to survival/growth and invasion/metastasis of many types of tumors bearing CCR2. Together, CCR2 links to two main types of suppressive immune cells by multiple mechanisms. Such a CCR2-assoicated immunosuppressive network is further entangled with paracrine and autocrine CCR2 signaling of tumor cells. Strategies to target CCL2/CCR2 axis as cancer therapy in the view of three types of CCR2-expessing cells in tumor microenvironment are discussed.

CPAP enhances and maintains chronic inflammation in hepatocytes to promote hepatocarcinogenesis

Chronic and persistent inflammation is a well-known carcinogenesis promoter. Hepatocellular carcinoma (HCC) is one of the most common inflammation-associated cancers; most HCCs arise in the setting of chronic inflammation and hepatic injury. Both NF-κB and STAT3 are important regulators of inflammation. Centrosomal P4.1-associated protein (CPAP), a centrosomal protein that participates primarily in centrosome functions, is overexpressed in HCC and can increase TNF-α-mediated NF-κB activation and IL-6-induced STAT3 activation. A transgenic (Tg) mouse model with hepatocyte-specific CPAP expression was established to investigate the physiological role of CPAP in hepatocarcinogenesis. Obvious inflammatory cell accumulation and fatty change were observed in the livers of CPAP Tg mice. The alanine aminotransferase (ALT) level and the expression levels of inflammatory genes, such as IL-6, IL-1β and TNF-α, were higher in CPAP Tg mice than in wild type (WT) mice. High-dose/short-term treatment with diethylnitrosamine (DEN) increased the ALT level, proinflammatory gene expression levels, and STAT3 and NF-κB activation in CPAP Tg mice; low-dose/long-term DEN treatment induced more severe liver tumor formation in CPAP Tg mice than in WT mice. CPAP can increase the expression of chemokine (C-C motif) ligand 16 (CCL-16), an important chemotactic cytokine, in human hepatocytes. CCL-16 expression is positively correlated with CPAP and TNF-α mRNA expression in the peritumoral part of HCC. In summary, these results suggest that CPAP may promote hepatocarcinogenesis through enhancing the inflammation pathway via increasing the expression of CCL-16.

Short stature and combined immunodeficiency associated with mutations in RGS10

We report the clinical and molecular phenotype of three siblings from one family, who presented with short stature and immunodeficiency and carried uncharacterized variants in RGS10 (c.489_491del:p.E163del and c.G511T:p.A171S). This gene encodes regulator of G protein signaling 10 (RGS10), a member of a large family of GTPase-activating proteins (GAPs) that targets heterotrimeric G proteins to constrain the activity of G protein-coupled receptors, including receptors for chemoattractants. The affected individuals exhibited systemic abnormalities directly related to the RGS10 mutations, including recurrent infections, hypergammaglobulinemia, profoundly reduced lymphocyte chemotaxis, abnormal lymph node architecture, and short stature due to growth hormone deficiency. Although the GAP activity of each RGS10 variant was intact, each protein exhibited aberrant patterns of PKA-mediated phosphorylation and increased cytosolic and cell membrane localization and activity compared to the wild-type protein. We propose that the RGS10 p.E163del and p.A171S mutations lead to mislocalization of the RGS10 protein in the cytosol, thereby resulting in attenuated chemokine signaling. This study suggests that RGS10 is critical for both immune competence and normal hormonal metabolism in humans and that rare RGS10 variants may contribute to distinct systemic genetic disorders.

Liver Fibrosis during Antiretroviral Treatment in HIV-Infected Individuals. Truth or Tale?

After the introduction of antiretroviral treatment (ART) back in 1996, the lifespan of people living with HIV (PLWH) has been substantially increased, while the major causes of morbidity and mortality have switched from opportunistic infections and AIDS-related neoplasms to cardiovascular and liver diseases. HIV itself may lead to liver damage and subsequent liver fibrosis (LF) through multiple pathways. Apart from HIV, viral hepatitis, alcoholic and especially non-alcoholic liver diseases have been implicated in liver involvement among PLWH. Another well known cause of hepatotoxicity is ART, raising clinically significant concerns about LF in long-term treatment. In this review we present the existing data and analyze the association of LF with all ART drug classes. Published data derived from many studies are to some extent controversial and therefore remain inconclusive. Among all the antiretroviral drugs, nucleoside reverse transcriptase inhibitors, especially didanosine and zidovudine, seem to carry the greatest risk for LF, with integrase strand transfer inhibitors and entry inhibitors having minimal risk. Surprisingly, even though protease inhibitors often lead to insulin resistance, they do not seem to be associated with a significant risk of LF. In conclusion, most ART drugs are safe in long-term treatment and seldom lead to severe LF when no liver-related co-morbidities exist.

Does C-C Motif Chemokine Ligand 2 (CCL2) Link Obesity to a Pro-Inflammatory State?

The mechanisms of how obesity contributes to the development of cardio-metabolic diseases are not entirely understood. Obesity is frequently associated with adipose tissue dysfunction, characterized by, e.g., adipocyte hypertrophy, ectopic fat accumulation, immune cell infiltration, and the altered secretion of adipokines. Factors secreted from adipose tissue may induce and/or maintain a local and systemic low-grade activation of the innate immune system. Attraction of macrophages into adipose tissue and altered crosstalk between macrophages, adipocytes, and other cells of adipose tissue are symptoms of metabolic inflammation. Among several secreted factors attracting immune cells to adipose tissue, chemotactic C-C motif chemokine ligand 2 (CCL2) (also described as monocyte chemoattractant protein-1 (MCP-1)) has been shown to play a crucial role in adipose tissue macrophage infiltration. In this review, we aimed to summarize and discuss the current knowledge on CCL2 with a focus on its role in linking obesity to cardio-metabolic diseases.

CC Chemokines in a Tumor: A Review of Pro-Cancer and Anti-Cancer Properties of the Ligands of Receptors CCR1, CCR2, CCR3, and CCR4

CC chemokines, a subfamily of 27 chemotactic cytokines, are a component of intercellular communication, which is crucial for the functioning of the tumor microenvironment. Although many individual chemokines have been well researched, there has been no comprehensive review presenting the role of all known human CC chemokines in the hallmarks of cancer, and this paper aims at filling this gap. The first part of this review discusses the importance of CCL1, CCL3, CCL4, CCL5, CCL18, CCL19, CCL20, CCL21, CCL25, CCL27, and CCL28 in cancer. Here, we discuss the significance of CCL2 (MCP-1), CCL7, CCL8, CCL11, CCL13, CCL14, CCL15, CCL16, CCL17, CCL22, CCL23, CCL24, and CCL26. The presentation of each chemokine includes its physiological function and then the role in tumor, including proliferation, drug resistance, migration, invasion, and organ-specific metastasis of tumor cells, as well as the effects on angiogenesis and lymphangiogenesis. We also discuss the effects of each CC chemokine on the recruitment of cancer-associated cells to the tumor niche (eosinophils, myeloid-derived suppressor cells (MDSC), tumor-associated macrophages (TAM), tumor-associated neutrophils (TAN), regulatory T cells (T_reg)). On the other hand, we also present the anti-cancer properties of CC chemokines, consisting in the recruitment of tumor-infiltrating lymphocytes (TIL).

CC motif chemokine ligand 16 inhibits the progression of liver cirrhosis via inactivating hepatic stellate cells

BACKGROUND

Liver cirrhosis results from many forms of chronic damage, characterized by accumulation of extracellular matrix. The present study aimed to explore a potential non-invasive biomarker and its mechanism in the progression of liver cirrhosis.

METHODS

Gene Expression Omnibus (GEO) dataset (GSE15654, n = 216) was analyzed to screen genes associated with progression of liver cirrhosis. A total of 181 plasma samples, including healthy control (HC, n = 20), chronic hepatitis B (CHB, n = 77) and HBV-related liver cirrhosis (LC, n = 84), were enrolled for validation. In vitro and in vivo experiments were employed for the mechanistic investigation.

RESULTS

GEO dataset analysis showed that relatively low mRNA-expression of CC motif chemokine ligand 16 (CCL16) was associated with elevated Child-Pugh score (P = 0.034) and worse prognosis (P = 0.025). Plasma CCL16 level decreased in a stepwise pattern, with a median concentration of 10.29, 6.57 and 4.47 ng/mL in the HC, CHB and LC groups, respectively (P<0.001). Low plasma CCL16 was significantly related to hepatic dysfunction both in the CHB and LC groups (P<0.05). Combination of CCL16 and ALT showed improved distinguishing capability for LC compared to either alone. In vitro, CCL16 expression was downregulated by lipopolysaccharide and hypoxia. Overexpression of CCL16 from human normal liver cell line (LO2) reduced the extracellular matrix associated proteins (Col1 and Col4) in human hepatic stellate cell line (LX-2). In vivo, the pathological feature of cirrhosis was alleviated by the hepatocyte-specific expression of CCL16.

CONCLUSIONS

CCL16 could be a feasible plasma marker to predict the occurrence and progression of liver cirrhosis. CCL16 might impact liver cirrhosis through inactivating hepatic stellate cells.

Improvement in Hepatic Fibrosis Biomarkers Associated With Chemokine Receptor Inactivation Through Mutation or Therapeutic Blockade

BACKGROUND

The C-C chemokine receptor Type 5 (CCR5) is a key receptor for human immunodeficiency virus type 1 (HIV-1) entry into T-cells and a variant allele, CCR5 delta-32, is associated with decreased viral replication and disease progression. Active HIV-1 replication is highly associated with accelerated rates of hepatic fibrosis. We postulated that CCR5 plays a role in the development of hepatic fibrosis and evaluated the longitudinal effect of natural or drug-induced CCR5 mutation and blockade on biomarkers of liver fibrosis in HIV-1 patients.

METHODS

To accomplish this goal, we examined 2 distinct cohorts. First, we evaluated fibrosis markers in the Multicenter Hemophilia Cohort Studies (MHCS), which included subjects with HIV and hepatitis C virus (HCV) coinfection with the CCR5 delta-32 allele. We also evaluated an HIV-1 infected cohort that was treated with a dual CCR5/CCR2 antagonist, cenicriviroc. The enhanced liver fibrosis (ELF) index was validated against liver histology obtained from HCV/HIV and HCV patients and demonstrated strong correlation with fibrosis stage.

RESULTS

In both the MHCS patients and patients treated with cenicriviroc, CCR5 mutation or blockade was associated with a significant decrease in the ELF index. Among the patients with the delta-32 allele, the ELF index rate significantly decreased in sequential samples as compared to CCR5 wild-type patients (P = .043). This was not observed in control subjects treated with efavirenz nor with a lower dose of 100 mg cenicriviroc.

CONCLUSION

These findings suggest that hepatic fibrosis in HIV-1 infected patients can be modulated by the mutation of CCR5 and/or use of CCR5/CCR2 blockade agents.

CLINICAL TRIALS REGISTRATION

NCT01338883.

Stimulation of histamine H4 receptor participates in cold-induced browning of subcutaneous white adipose tissue

Although many studies have shown that histamine and its signaling regulate energy homeostasis through the central nervous system, their roles in adipose tissues remain poorly understood. Here, we identified that the histamine H4 receptor (HrH4) was highly expressed in adipocytes at a level higher than that of the other three receptors (i.e., HrH1, HrH2, and HrH3). The HrH4 expression in adipocytes responded to cold through thermogenesis and lipolysis, supported by results from both mouse and cell models. When HrH4 expression was knocked down in the subcutaneous white adipose tissue (scWAT), browning and lipolysis effects triggered by cold were ablated, and the oxygen consumption was also lowered both at the normal and cold conditions. Moreover, mice exhibited browned scWAT, accelerated metabolic rates, and tolerance to hypothermia when 4-methylhistamine (4MH), a selective HrH4 agonist, was adjacently injected to the scWAT. Consistent with these findings, 4MH also triggered the browning and lipolytic effects in cultured C3H10T1/2 adipocytes. Mechanically, we demonstrated that p38/MAPK and ERK/MAPK pathways were involved in these processes. In conclusion, our findings have uncovered an effective role of HrH4 in adipose tissue browning.

CCR5 receptor antagonism inhibits hepatitis C virus (HCV) replication in vitro

Background and aim

The hepatitis C virus (HCV) is a single-strand RNA virus that infects millions of people worldwide. Recent advances in therapy have led to viral cure using two- and three- drug combinations of direct acting inhibitors of viral replication. CCR5 is a chemokine receptor that is expressed on hepatocytes and represents a key co-receptor for HIV. We evaluated the effect of CCR5 blockade or knockdown on HCV replication in Huh7.5_JFH1 cells.

Methods

Cells were exposed to varying concentrations of maraviroc (CCR5 inhibitor), cenicriviroc (CCR2/CCR5 inhibitor), sofosbuvir (nucleotide polymerase inhibitor), or raltegravir (HIV integrase inhibitor).

Results

HCV RNA was detected utilizing two qualitative strand-specific RT-PCR assays. HCV core antigen and NS3 protein was quantified in the supernatant and cell lysate, respectively. siRNA was utilized to knockdown CCR5 gene expression in hepatocytes. Alternatively, anti-CCR5 antibodies were employed to block the receptor. Supernatant levels of HCV RNA (expressed as fold change) were not reduced in the presence of raltegravir but were reduced 8.55-fold and 12.42-fold with cenicriviroc and maraviroc, respectively. Sofosbuvir resulted in a 16.20-fold change in HCV RNA levels. HCV core and NS3 protein production was also reduced in a dose-dependent manner. Two distinct anti-CCR5 antibodies also resulted in a significant reduction in HCV protein expression, as did siRNA knockdown of CCR5 gene expression.

Conclusions

These data provide evidence that CCR5 modulation could have a significant effect on HCV replication in an in vitro system. Further evaluation of the role of CCR5 inhibition in clinical settings may be warranted.

Gestational restricted- and over-feeding promote maternal and offspring inflammatory responses that are distinct and dependent on diet in sheep

Inflammation may be a mechanism of maternal programming because it has the capacity to alter the maternal environment and can persist postnatally in offspring tissues. This study evaluated the effects of restricted- and over-feeding on maternal and offspring inflammatory gene expression using reverse transcription (RT)-PCR arrays. Pregnant ewes were fed 60% (Restricted), 100% (Control), or 140% (Over) of National Research Council requirements beginning on day 30.2 ± 0.2 of gestation. Maternal (n = 8-9 ewes per diet) circulating nonesterified fatty acid (NEFA) and expression of 84 inflammatory genes were evaluated at five stages during gestation. Offspring (n = 6 per diet per age) inflammatory gene expression was evaluated in the circulation and liver at day 135 of gestation and birth. Throughout gestation, circulating NEFA increased in Restricted mothers but not Over. Expression of different proinflammatory mediators increased in Over and Restricted mothers, but was diet-dependent. Maternal diet altered offspring systemic and hepatic expression of genes involved in chemotaxis at late gestation and cytokine production at birth, but the offspring response was distinct from the maternal. In the perinatal offspring, maternal nutrient restriction increased hepatic chemokine (CC motif) ligand 16 and tumor necrosis factor expression. Alternately, maternal overnutrition increased offspring systemic expression of factors induced by hypoxia, whereas expression of factors regulating hepatocyte proliferation and differentiation were altered in the liver. Maternal nutrient restriction and overnutrition may differentially predispose offspring to liver dysfunction through an altered hepatic inflammatory microenvironment that contributes to immune and metabolic disturbances postnatally.

Attributes of alternatively activated (M2) macrophages

Macrophages are cells of innate immunity and are derived from circulating monocytes and embryonic yolk sac. They exhibit high plasticity and polarize functionally in response to stimulus triggering it into classically activated M1 macrophages and alternatively activated M2 macrophages. This review summarizes markers of M2 macrophages like transmembrane surface receptors and signaling cascades initiated on their activation; cytokine and chemokine repertoires along with their receptors; and genetic markers and their involvement in immunomodulation. The detailed discussion emphasizes the role of these markers in imparting functional benefits to this subset of macrophages which define their venture in various physiological and pathological conditions.

Evolution of CCL16 in Glires (Rodentia and Lagomorpha) shows an unusual random pseudogenization pattern

Background

The C-C motif chemokine ligand 16 (CCL16) is a potent pro-inflammatory chemokine and a chemoattractant for monocytes and lymphocytes. In normal plasma, it is present at high concentrations and elicits its effects on cells by interacting with cell surface chemokine receptors. In the European rabbit and in rodents such as mouse, rat and guinea pig, CCL16 was identified as a pseudogene, while in the thirteen-lined ground squirrel it appears to be potentially functional. To gain insight into the evolution of this gene in the superorder Glires (rodents and lagomorphs), we amplified the CCL16 gene from eleven Leporidae and seven Ochotonidae species.

Results

We compared our sequences with CCL16 sequences of twelve rodent species retrieved from public databases. The data show that for all leporid species studied CCL16 is a pseudogene. This is primarily due to mutations at the canonical Cys Cys motif, creating either premature stop codons, or disrupting amino acid replacements. In the Mexican cottontail, CCL16 is pseudogenized due to a frameshift deletion. Additionally, in the exon 1 (signal peptide), there are frameshift deletions present in all leporids studied. In contrast, in Ochotona species, CCL16 is potentially functional, except for an allele in Hoffmann’s pika. In rodents, CCL16 is functional in a number of species, but patterns of pseudogenization similar to those observed in lagomorphs also exist.

Conclusions

Our results suggest that while functional in the Glires ancestor, CCL16 underwent pseudogenization in some species. This process occurred stochastically or in specific lineages at different moments in the evolution of Glires. These observations suggest that the CCL16 had different evolutionary constrains in the Glires group that could be associated with the CCL16 biological function.

Electronic supplementary material

The online version of this article (10.1186/s12862-019-1390-7) contains supplementary material, which is available to authorized users.

Mechanisms of Accelerated Liver Fibrosis Progression during HIV Infection

With the introduction of antiretroviral therapy (ART), a dramatic reduction in HIV-related morbidity and mortality has been observed. However, it is now becoming increasingly clear that liver-related complications, particularly rapid fibrosis development from ART as well as from the chronic HIV infection itself, are of serious concern to HIV patients. The pathophysiology of liver fibrosis in patients with HIV is a multifactorial process whereby persistent viral replication, and bacterial translocation lead to chronic immune activation and inflammation, which ART is unable to fully suppress, promoting production of fibrinogenic mediators and fibrosis. In addition, mitochondrial toxicity, triggered by both ART and HIV, contributes to intrahepatic damage, which is even more severe in patients co-infected with viral hepatitis. In recent years, new insights into the mechanisms of accelerated fibrosis and liver disease progression in HIV has been obtained, and these are detailed and discussed in this review.

RP S19 C-terminal peptide trimer acts as a C5a receptor antagonist

We have demonstrated that ribosomal protein S19 (RP S19) polymer, when crosslinked between Lys122 and Gln137 by activated coagulation factor XIII, acts as a C5a receptor (C5aR) antagonist/agonist. Based on experimental data obtained using RP S19 analog peptide and recombinant protein monomer, we suggested that L₁₃₁DR, I₁₃₄AGQVAAAN and K₁₄₃KH moieties in the RP S19 C‐terminus act in, respectively, C5aR binding, penetration of the plasma membrane, and interaction with either an apoptosis-inducing molecule in neutrophils (delta lactoferrin) or a calcium channel-activating molecule (annexin A3) to induce the p38 MAPK pathway in macrophages. Recently, we observed RP S19 trimer in serum. To study the effects of this RP S19 trimer on C5aR, we prepared mutant RP S19 C‐terminal peptide (RP S19^122-145) dimer and trimer, and examined their chemotactic activities and signal transduction pathways in human C5aR-overexpressing squamous cell carcinoma HSC-1 (HSC-1^C5aR) cells using 24 trans-well chamber and western blotting assays, respectively. HSC-1^C5aR cells were attracted by RP S19^122-145 dimer and vice versa by RP S19^122-145 trimer. The RP S19^122-145 dimer-induced attraction was competitively blocked by pre-treatment with RP S19^122-145 trimer. Moreover, RP S19^122-145 trimer-induced p38 MAPK phosphorylation was stronger than RP S19^122-145 dimer-induced p38 MAPK phosphorylation. RP S19^122-145 trimer appeared to act as a C5aR antagonist. The agonistic and antagonistic effects of RP S19^122-145 dimers and trimers were reflected by monocytic, THP-1-derived macrophage-like cells. Unlike the C5aR agonist C5a, which acts at the inflammation phase of acute inflammation, RP S19 trimer might act as a C5aR antagonist at the resolution phase.

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RP S19 dimer acted as C5aR antagonist/agonist.

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RP S19 dimer induced p38MAPK and ERK1/2 signal.

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RP S19 trimer acted as C5aR antagonist.

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RP S19 trimer induced p38MAPK signal.

Phase 1 Dose-Escalation Study with LEC/chTNT-3 and Toceranib Phosphate (Palladia®) in Dogs with Spontaneous Malignancies

OBJECTIVES

LEC chemokine promotes TH1 responses and recruits immune cells to inflammatory sites. By linking LEC to an antibody targeting tumor necrosis, LEC/chTNT-3 can be used for the immunotherapeutic treatment of tumors. The primary objective of this study was to determine the safety profile of LEC/chTNT-3 and toceranib phosphate (Palladia^®) combination therapy in dogs with spontaneous malignancies. Secondary purpose was to determine objective responses to treatment.

METHODS

Twenty-three dogs with cancer were enrolled, covering nine different malignancies. In this dose escalation study, dogs received LEC/chTNT-3 for five days, and toceranib every 48 hours for the remainder of the study. Dogs received physical exams, chemistry panel, urinalysis, and complete blood counts on days 0, 10, 28 of the study, and every 6-8 weeks thereafter.

RESULTS

Lethargy was noted in 13% dogs. There were no statistical differences in the prevalence of anorexia, diarrhea, thrombocytopenia, renal toxicity, or hepatic toxicity before or during the study. There were trends in increases in the prevalence of vomiting, lymphopenia, and neutropenia (all grade 2 or lower, p=0.07) over the initial 28 days of the study. By day 28, 10% of dogs had partial responses, 58% had stable disease, and 32% had progressive disease.

CONCLUSIONS

LEC/chTNT-3 and toceranib were well tolerated. This combination therapy showed some biological activity against a variety of cancers at a low dose and short duration of LEC/chTNT-3 administration.

A draft network of ligand-receptor-mediated multicellular signalling in human

Cell-to-cell communication across multiple cell types and tissues strictly governs proper functioning of metazoans and extensively relies on interactions between secreted ligands and cell-surface receptors. Herein, we present the first large-scale map of cell-to-cell communication between 144 human primary cell types. We reveal that most cells express tens to hundreds of ligands and receptors to create a highly connected signalling network through multiple ligand-receptor paths. We also observe extensive autocrine signalling with approximately two-thirds of partners possibly interacting on the same cell type. We find that plasma membrane and secreted proteins have the highest cell-type specificity, they are evolutionarily younger than intracellular proteins, and that most receptors had evolved before their ligands. We provide an online tool to interactively query and visualize our networks and demonstrate how this tool can reveal novel cell-to-cell interactions with the prediction that mast cells signal to monoblastic lineages via the CSF1-CSF1R interacting pair.

CCL5/RANTES is important for inducing osteogenesis of human mesenchymal stem cells and is regulated by dexamethasone

In this study, we examine the effect of chemokine (C-C motif) ligand 5 (CCL5)/Regulated on Activation Normal T cell Expressed and Secreted (RANTES), a pro-inflammatory cytokine on osteogenic differentiation of human mesenchymal stem cells (hMSCs). We found CCL5 expression was increased during osteogenic differentiation of hMSCs and CCL5 expression is dependent on the presence of dexamethasone. Knocking down endogenous CCL5 expression blocked osteogenesis, as revealed by decreasing alkaline phosphatase (ALP) activity and a reduction in the expression levels of ALP, bone sialoprotein (BSP), and osteopontin (OPN). Of note, the overexpression of CCL5 was sufficient to increase ALP expression and activity. Moreover, the down-regulation of chemokine (C-C motif) receptor 1 (CCR1), one of the CCL5 receptors, significantly decreased the osteogenesis of hMSCs. Interestingly, the down-regulation of CCR1, but not CCL5, was sufficient to affect the cell numbers during the process of osteogenesis. Our findings reveal that both CCL5 and CCR1 are required for osteogenesis of human MSCs, CCL5 is sufficient for the osteogenesis, and provide a novel link between dexamethasone and CCL5 in human osteogenesis.

Chemokines in chronic liver allograft dysfunction pathogenesis and potential therapeutic targets

Despite advances in immunosuppressive drugs, long-term success of liver transplantation is still limited by the development of chronic liver allograft dysfunction. Although the exact pathogenesis of chronic liver allograft dysfunction remains to be established, there is strong evidence that chemokines are involved in organ damage induced by inflammatory and immune responses after liver surgery. Chemokines are a group of low-molecular-weight molecules whose function includes angiogenesis, haematopoiesis, mitogenesis, organ fibrogenesis, tumour growth and metastasis, and participating in the development of the immune system and in inflammatory and immune responses. The purpose of this review is to collect all the research that has been done so far concerning chemokines and the pathogenesis of chronic liver allograft dysfunction and helpfully, to pave the way for designing therapeutic strategies and pharmaceutical agents to ameliorate chronic allograft dysfunction after liver transplantation.

International Union of Basic and Clinical Pharmacology. [corrected]. LXXXIX. Update on the extended family of chemokine receptors and introducing a new nomenclature for atypical chemokine receptors

Sixteen years ago, the Nomenclature Committee of the International Union of Pharmacology approved a system for naming human seven-transmembrane (7TM) G protein-coupled chemokine receptors, the large family of leukocyte chemoattractant receptors that regulates immune system development and function, in large part by mediating leukocyte trafficking. This was announced in Pharmacological Reviews in a major overview of the first decade of research in this field [Murphy PM, Baggiolini M, Charo IF, Hébert CA, Horuk R, Matsushima K, Miller LH, Oppenheim JJ, and Power CA (2000) Pharmacol Rev 52:145-176]. Since then, several new receptors have been discovered, and major advances have been made for the others in many areas, including structural biology, signal transduction mechanisms, biology, and pharmacology. New and diverse roles have been identified in infection, immunity, inflammation, development, cancer, and other areas. The first two drugs acting at chemokine receptors have been approved by the U.S. Food and Drug Administration (FDA), maraviroc targeting CCR5 in human immunodeficiency virus (HIV)/AIDS, and plerixafor targeting CXCR4 for stem cell mobilization for transplantation in cancer, and other candidates are now undergoing pivotal clinical trials for diverse disease indications. In addition, a subfamily of atypical chemokine receptors has emerged that may signal through arrestins instead of G proteins to act as chemokine scavengers, and many microbial and invertebrate G protein-coupled chemokine receptors and soluble chemokine-binding proteins have been described. Here, we review this extended family of chemokine receptors and chemokine-binding proteins at the basic, translational, and clinical levels, including an update on drug development. We also introduce a new nomenclature for atypical chemokine receptors with the stem ACKR (atypical chemokine receptor) approved by the Nomenclature Committee of the International Union of Pharmacology and the Human Genome Nomenclature Committee.

The role of inflammatory chemokines in lymphoid neoorganogenesis in breast cancer

The expression profiling analysis of inflammatory chemokines and their receptors in newly formed lymph nodes in breast cancer was carried out. The analysis revealed the increase in expression of the genes CCL16, XCR1, CYFIP2, TNFSF14 and the reduction in expression of chemokine ligands CXCL5 and CXCL12 in tertiary lymphoid organs. The obtained results allow us to suggest that the process of induction of lymph nodes neogenesis is identical (in its key mechanisms) to the process of lymphoid tissue neogenesis in autoimmune diseases and in some infections, but may have different triggers.

Identification of serum CCL15 in hepatocellular carcinoma

Background:

Early serum detection is of critical importance to improve the therapy for hepatocellular carcinoma (HCC), one of the most deadly cancers. Hepatitis infection is a leading cause of HCC.

Methods:

In the present study, we collected total serum samples with informed consent from 80 HCC patients with HBV (+)/cirrhosis (+), 80 patients with benign diseases (50 liver cirrhosis patients and 30 HBV-infected patients) and 60 healthy controls. Analysis was by using surface-enhanced laser desorption/ionisation-time-of-flight mass spectroscopy (SELDI-TOF-MS) to find new serum markers of HCC. SELDI peaks were isolated by SDS–PAGE, identified by LC-MS/MS and validated by immunohistochemistry (IHC) in liver tissues. Migration and invasion assay were performed to test the ability of cell migration and invasion in vitro.

Results:

SELDI-TOF-MS revealed a band at 7777 M/Z in the serum samples from HCC patients but not from healthy controls or patients with benign diseases. The protein (7777.27 M/Z) in the proteomic signature was identified as C-C motif chemokine 15 (CCL15) by peptide mass fingerprinting. A significant increase in serum CCL15 was detected in HCC patients. Functional analysis showed that HCC cell expressed CCL15, which in turn promoted HCC cell migration and invasion.

Conclusion:

CCL15 may be a specific proteomic biomarker of HCC, which has an important role in tumorigenesis and tumour invasion.

The possible diagnostic and prognostic use of systemic chemokine profiles in clinical medicine—the experience in acute myeloid leukemia from disease development and diagnosis via conventional chemotherapy to allogeneic stem cell transplantation

Chemokines are important regulators of many different biological processes, including (i) inflammation with activation and local recruitment of immunocompetent cells; (ii) angiogenesis as a part of inflammation or carcinogenesis; and (iii) as a bridge between the coagulation system and inflammation/immune activation. The systemic levels of various chemokines may therefore reflect local disease processes, and such variations may thereby be used in the routine clinical handling of patients. The experience from patients with myeloproliferative diseases, and especially patients with acute myeloid leukemia (AML), suggests that systemic plasma/serum cytokine profiles can be useful, both as a diagnostic tool and for prognostication of patients. However, cytokines/chemokines are released by a wide range of cells and are involved in a wide range of biological processes; the altered levels may therefore mainly reflect the strength and nature of the biological processes, and the optimal clinical use of chemokine/cytokine analyses may therefore require combination with organ-specific biomarkers. Chemokine levels are also altered by clinical procedures, therapeutic interventions and the general status of the patients. A careful standardization of sample collection is therefore important, and the interpretation of the observations will require that the overall clinical context is considered. Despite these limitations, we conclude that analysis of systemic chemokine/cytokine profiles can reflect important clinical characteristics and, therefore, is an important scientific tool that can be used as a part of future clinical studies to identify clinically relevant biomarkers.

Antimicrobial chemokines

Chemokines are best known for their classic leukocyte chemotactic activity, which is critical for directing the immune response to sites of infection and injury. However, recent studies have suggested that at least some chemokines may also interfere with infectious agents directly. Antimicrobial chemokines tend to contain amphipathic alpha helical secondary structure, and broad-spectrum activity against both Gram-positive and Gram negative bacteria, as well as fungi. Conversely, several bacteria have been identified that possess mechanisms for specifically blocking the antimicrobial activities of chemokines. Although the precise mechanisms by which chemokines and microbes disarm one another in vitro remain unknown, there is now emerging evidence in vivo that such interactions may be biologically significant. More research will be needed to determine whether chemokines with direct antimicrobial activity may be translated into a novel class of antibiotics.

Monocyte chemoattractant protein-1/CCR2 axis promotes vein graft neointimal hyperplasia through its signaling in graft-extrinsic cell populations

OBJECTIVE

To evaluate direct versus indirect monocyte chemoattractant protein (MCP)-1/CCR2 signaling and to identify the cellular producers and effectors for MCP-1 during neointimal hyperplasia (NIH) development in vein grafts.

METHODS AND RESULTS

Genomic analysis revealed an overrepresentation of 13 inflammatory pathways in wild-type vein grafts compared with CCR2 knockout vein grafts. Further investigation with various vein graft-host combinations of MCP-1- and CCR2-deficient mice was used to modify the genotype of cells both inside (graft-intrinsic group) and outside (graft-extrinsic group) the vein wall. CCR2 deficiency inhibited NIH only when present in cells extrinsic to the graft wall, and MCP-1 deficiency required its effectiveness in cells both intrinsic and extrinsic to the graft wall to suppress NIH. Deletion of either MCP-1 or CCR2 was equally effective in inhibiting NIH. CCR2 deficiency in the predominant neointimal cell population had no impact on NIH. Direct MCP-1 stimulation of primary neointimal smooth muscle cells had minimal influence on cell proliferation and matrix turnover, confirming an indirect mechanism of action.

CONCLUSIONS

MCP-1/CCR2 axis accelerates NIH via its signaling in graft-extrinsic cells, particularly circulating inflammatory cells, with cells both intrinsic and extrinsic to the graft wall being critical MCP-1 producers. These findings underscore the importance of systemic treatment for anti-MCP-1/CCR2 therapies.

Umbilical artery chemokine CCL16 is associated with preterm preeclampsia and fetal growth restriction

BACKGROUND

Cytokines and growth factors synthesized by placental trophoblasts are suggested to induce endothelial and vascular smooth muscle cell apoptosis and affect angiogenesis.

OBJECTIVE

To investigate cord blood and placental immunoproteins in order to find new clues on pathogenetic factors of preterm preeclampsia.

METHODS

Cord blood samples were collected on 163 consecutive preterm deliveries prior to 32 gestational weeks. Placental function, clinical risk factors and 107 umbilical artery immunoproteins were analyzed. Classification and regression trees analysis was used to detect associations between the immunoproteins, clinical parameters and preterm preeclampsia. Placental expression of the immunoproteins and their receptors were subsequently investigated.

RESULTS

Preeclampsia complicated 34% of the pregnancies in this preterm cohort. Umbilical artery CCL16, CCL24, and CCL23 were associated with preeclampsia, CCL16 showing the strongest relationship with an OR (95% CI) of 24.5 (5.4-112.0). High umbilical artery CCL16 was also characteristic to fetuses with severe growth restriction (<3rd percentile). CCL16, CCL24 and their receptors, CCR1 and CCR3 were expressed in preeclamptic placentas.

CONCLUSIONS

High umbilical artery CCL16 is prominently detected in preterm preeclamptic pregnancies with severe growth restriction. A link to compensatory proangiogenic mechanisms has to be considered.

[Old immune system- new information? Importance of mononuclear phagocytes in corneal allograft rejection]

Mononuclear phagocytes are derived from bone marrow precursor cells and are part of the innate immune system. These cells circulate in the blood as monocytes but differentiate in the peripheral circulation into tissue macrophages and dendritic cells under the influence of various cytokines. In addition to antimicrobial properties, macrophages also participate in wound healing; however, they also support degenerative and inflammatory processes. In cases of acute corneal allograft rejection, mononuclear cells initially form the main component of the cellular anterior chamber infiltrate. How monocytes are recruited into the anterior chamber is currently uncertain. Furthermore, no information is available about the possible cytotoxic effects on corneal endothelial cells. Gaining insight into these mechanisms may lead to potential pharmacological interventions.

Chitooligosaccharide elicits acute inflammatory cytokine response through AP-1 pathway in human intestinal epithelial-like (Caco-2) cells

Chitooligosaccharides (COSs) are bioactive carbohydrate derivatives that have numerous health benefits, including stimulation of the immune system. The objectives of this study were to evaluate the effect of chitooligosaccharide (COS) on expression of a specific panel of cytokine genes involved in inflammation and to delineate the signal transduction pathway underlying the COS mediated inflammatory response. Human intestinal epithelial-like (Caco-2) cells were treated with COS (5000-10,000Da) and expression of a panel of eighty-four cytokine genes was analyzed by quantitative real-time PCR. COS induced up-regulation of a total of 11 genes including CCL20 and IL8 and concurrent down-regulation of 10 genes including pro-inflammatory mediators CCL15, CCL25 and IL1B. To further establish the signal transduction pathway of COS mediated response in Caco-2 cells, two major inflammatory signal transduction pathways (NF-κB and AP-1) were investigated. COS had inhibitory effect (P<0.01) on TNF-α induced NF-κB binding activity while stimulatory effect (P<0.001) on AP-1 binding activity. COS also inhibited the expression of RELA (P<0.01) and IKBKB (P<0.01) genes of NF-κB pathway while stimulate the expression of JUN (P<0.05) gene of AP-1 pathway. In conclusion, COS elicits an acute inflammatory cytokine response in Caco-2 cells and hence it has the potential to stimulate the immune system in the gut epithelium.

Pro-inflammatory chemokine C-C motif ligand 16 (CCL-16) dysregulation in irritable bowel syndrome (IBS): a pilot study

BACKGROUND

Irritable bowel syndrome (IBS) is a serious health problem that affects an estimated 10-15% of people worldwide and has economic consequences in the United States of over $30 billion annually. In the US, IBS affects all races and both sexes, with more females than males (2:1) reporting symptoms consistent with IBS. Although the etiology of this functional gastrointestinal disorder is unknown, literature suggests that a subclinical inflammatory component has a role in the etiologic mechanisms underlying IBS. The aim of this study was to evaluate the gene expression of inflammatory biomarkers in patients with and without IBS and among different IBS phenotypes.

METHODS

Irritable bowel syndrome patients (n=12) that met Rome III Criteria for IBS longer than 6months were compared with healthy matched controls (n=12). Peripheral whole blood from fasting participants was collected and RNA was extracted. The expression of 96 inflammatory genes was then analyzed using a custom quantitative real-time PCR array.

KEY RESULTS

CCL-16 gene expression was upregulated by 7.46-fold in IBS patients when compared with controls. CCL-16 was overexpressed by over 130-fold in IBS-constipation patients when compared with both controls and IBS-diarrhea patients.

CONCLUSIONS & INFERENCES

These results further suggest a subclinical inflammatory component underlying IBS. To better understand the phenotypic differences in IBS it is important to broaden the study of these inflammatory and other biomarkers.

Multifunctional core-shell nanoparticles: discovery of previously invisible biomarkers

Many low-abundance biomarkers for early detection of cancer and other diseases are invisible to mass spectrometry because they exist in body fluids in very low concentrations, are masked by high-abundance proteins such as albumin and immunoglobulins, and are very labile. To overcome these barriers, we created porous, buoyant, core-shell hydrogel nanoparticles containing novel high affinity reactive chemical baits for protein and peptide harvesting, concentration, and preservation in body fluids. Poly(N-isopropylacrylamide-co-acrylic acid) nanoparticles were functionalized with amino-containing dyes via zero-length cross-linking amidation reactions. Nanoparticles functionalized in the core with 17 different (12 chemically novel) molecular baits showed preferential high affinities (K(D) < 10(-11) M) for specific low-abundance protein analytes. A poly(N-isopropylacrylamide-co-vinylsulfonic acid) shell was added to the core particles. This shell chemistry selectively prevented unwanted entry of all size peptides derived from albumin without hindering the penetration of non-albumin small proteins and peptides. Proteins and peptides entered the core to be captured with high affinity by baits immobilized in the core. Nanoparticles effectively protected interleukin-6 from enzymatic degradation in sweat and increased the effective detection sensitivity of human growth hormone in human urine using multiple reaction monitoring analysis. Used in whole blood as a one-step, in-solution preprocessing step, the nanoparticles greatly enriched the concentration of low-molecular weight proteins and peptides while excluding albumin and other proteins above 30 kDa; this achieved a 10,000-fold effective amplification of the analyte concentration, enabling mass spectrometry (MS) discovery of candidate biomarkers that were previously undetectable.

Cord blood chemokines differentiate between spontaneous and elective preterm births in singleton pregnancies

BACKGROUND

Signals originating from both maternal and fetal compartments participate in the preterm labor process.

OBJECTIVE

To investigate whether cord blood immunoproteins predict spontaneous preterm labor.

METHODS

Cord blood from 125 very preterm (gestational age <32weeks) singleton infants and 33 term infants was collected after birth and analyzed for 107 immunoproteins on microarrays. Immunoproteins from spontaneous preterm births (SPTB) were compared to immunoproteins from preterm births without labor. The placentas were studied for histology and immunohistochemistry. The data was modeled by classification and regression trees (CART) analysis.

RESULTS

In preterm births, low CCL16 level predicted SPTB with a sensitivity of 94.7%, and specificity of 46.9%. According to logistic regression analysis, low CCL16 (OR 57.9), histologic chorioamnitis (OR 33.6), and high CCL23 (OR 44.6) were independent risk factors of SPTB. Cord blood CCL16 was higher in preterm births without labor and in term births than in SPTBs. CCL16 and its signaling receptor CCR1 were visualized in syncytiotrophoblast and cytotrophoblast cells of placental villi.

CONCLUSION

Low umbilical cord blood chemokine CCL16 associates with spontaneous preterm birth. Further studies are required to show whether CCL16 is involved in spontaneous preterm labor or in placental disease necessitating elective preterm delivery.

Elevated serum levels of CCL17 correlate with increased peripheral blood platelet count in patients with active tuberculosis in China

The serum levels of Th2 markers, including CCL17 (thymus and activation-regulated chemokine [TARC]), CCL22 (macrophage-derived chemokine [MDC]), and soluble CD30, were measured in 101 HIV-negative tuberculosis patients, 103 healthy community controls, and 18 tuberculosis patients in recovery. The levels of CCL17/TARC (249.8 ± 19.91 versus 143.9 ± 10.54, P < 0.0001) and sCD30 (7.78 ± 0.44 versus 4.93 ± 0.23, P < 0.0001) were significantly higher in patients with active tuberculosis than in controls; however, the CCL22/MDC serum level had no statistical difference between the groups (579.9 ± 16.42 versus 556.5 ± 15.29, P = 0.298). The counts of platelet and eosinophil in the peripheral blood of patients with active tuberculosis are significantly increased as well (289.4 ± 8.14 versus 248.3 ± 5.34 [P < 0.0001] and 165.1 ± 14.33 versus 102.5 ± 10.72 [P = 0.0005], respectively), and the platelet counts were positively correlated with serum TARC levels (Pearson r = 0.456, P < 0.0001), which indicates a new source of Th2 bias showing in active TB patients.

The evolution of mammalian chemokine genes

Chemokines play an important role in orchestrating cell recruitment and localization in both physiological and pathological conditions. More than 44 ligands have been identified in the human genome. A significantly different set of chemokines, however, is found in the mouse genome, suggesting a rapid evolution of the chemokine system in mammalian genomes. Thus, there are lineage and even individual-specific differences in chemokine genes in mammals. Differences in the expression and function between even recently duplicated genes are also evident. In this review, we discuss how evolutionary events such as gene duplication and gene conversion have shaped the diverse arrays of chemokines in mammalian genomes.

Abdominal aortic aneurysm: a review of the genetic basis

BACKGROUND

Abdominal aortic aneurysm (AAA) is a complex disease with a largely unknown pathophysiological background and a strong genetic component. Various studies have tried to link specific genetic variants with AAA.

METHODS

Systematic review of the literature (1947-2009).

RESULTS

A total of 249 studies were identified, 89 of which were eventually deemed relevant to this review. Genetic variants (polymorphisms) in a wide variety of genes, most of which encode proteolytic enzymes and inflammatory molecules, have been associated with AAA development and progression.

CONCLUSION

The genetic basis of AAA remains unknown, and most results from ''candidate-gene'' association studies are contradictory. Further analyses in appropriately powered studies in large, phenotypically well-characterized populations, including genome-wide association studies, are necessary to elucidate the exact genetic contribution to the pathophysiology of AAA.

Chemokine-directed immune cell infiltration in acute and chronic liver disease

The infiltration of various immune cell populations, including monocytes/macrophages, natural killer (NK), NKT cells and T cells, is a central pathogenic feature following acute- and chronic liver injury. Chemotactic cytokines, chemokines, are small-protein mediators that direct the migration of immune cells. Several hepatic cell populations, including hepatocytes, Kupffer cells, sinusoidal endothelial cells and hepatic stellate cells, can secrete chemokines upon activation. Samples from liver-disease patients and animal models of experimental injury highlight multiple activated chemokine pathways during initiation, maintenance or resolution of liver pathology. Monocyte chemoattractant protein-1 (Chemokine [C-C motif] ligand [CCL]2) can attract monocytes via CCR2. Infiltrating monocytes probably have functions in both disease progression and resolution of damage. RANTES (CCL5) may promote infiltration of NK (via CCR1) and T cells (via CCR5). Dissecting the exact functional contribution of immune cell subsets, chemokines and chemokine-receptor pathways in liver injury will hopefully identify novel targets for the treatment of acute liver failure, liver fibrosis or cirrhosis.

Tax-inducible production of CC chemokine ligand 22 by human T cell leukemia virus type 1 (HTLV-1)-infected T cells promotes preferential transmission of HTLV-1 to CCR4-expressing CD4+ T cells

Adult T cell leukemia is a mature CD4+ T cell malignancy which predominantly expresses CCR4 and is etiologically associated with human T cell leukemia virus type 1 (HTLV-1). Because HTLV-1 transmission depends on close cell-cell contacts, HTLV-1-infected T cells may preferentially interact with CCR4+CD4+ T cells for efficient viral transmission. In terms of gene expression and protein secretion, we found a strong correlation between HTLV-1 Tax oncoprotein and CCL22, a CCR4 ligand, in HTLV-1-infected T cells. Transient Tax expression in an HTLV-1-negative T cell line activated the CCL22 promoter and induced CCL22. Additionally, tax gene knockdown by small interference RNA reduced CCL22 expression in the infected T cells. These findings indicate that CCL22 is a cellular target gene of Tax. In chemotaxis assays, the culture supernatants of HTLV-1-infected T cells selectively attracted CCR4+CD4+ T cells in PBMCs. This was blocked by pretreating the supernatants with anti-CCL22 Ab or PBMCs with a synthetic CCR4 antagonist. In coculture experiments, primary CCR4+CD4+ T cells significantly adhered to Tax-expressing cells. This adhesion was blocked by the CCR4 antagonist or pertussis toxin. Interestingly, CCR4 was redistributed to the contact region, and in some cases, this was accompanied by a polarized microtubule-organizing center, which is an indicator of virological synapse formation, in the infected T cells. Finally, anti-CCL22 Ab treatment also blocked HTLV-1 transmission to primary CD4+ T cells in coculture experiments with HTLV-1 producer cells. Thus, HTLV-1-infected T cells produce CCL22 through Tax and selectively interact with CCR4+CD4+ T cells, resulting in preferential transmission of HTLV-1 to CCR4+CD4+ T cells.

Cytokine, chemokine, and co-stimulatory fusion proteins for the immunotherapy of solid tumors

This chapter describes the generation of novel reagents for the treatment of cancer using fusion proteins constructed with natural ligands of the immune system. Immunotherapy is a powerful therapeutic modality that has not been fully harnessed for the treatment of cancer. We and others have hypothesized that if the proper immunoregulatory ligands can be targeted to the tumor, an effective immune response can be mounted to treat both established primary tumors and distant metastatic lesions. Though it is generally believed that immunotherapy has the potential to treat only residual disease, we offer evidence that this approach can, by itself, destroy large tumor masses and produce lasting remissions of experimental solid tumors. From these studies, three major classes of immune activators, namely, cytokines, chemokines, and costimulatory molecules, have been shown to generate antitumor responses in animal models. In addition, the reversal of immune tolerance by the deletion of T regulatory (Treg) cells has been shown to be equally important for effective immunotherapy. In an attempt to identify reagents that can provide an enhanced immune stimulation and treatment of cancer, our laboratory has developed a novel monoclonal antibody targeting approach, designated Tumor Necrosis Therapy (TNT), which utilizes stable intracellular antigens present in all cell types but which are only accessible in dead and/or dying cells. Since tumors contain necrotic and degenerating regions that account for 30-80% of the tumor mass, this targeting approach can be used to deliver therapeutic reagents to the core of tumors, a site abundant in tumor antigens. In our first set of reagents, a panel of cytokine fusion proteins was genetically engineered using monoclonal antibody chimeric TNT-3 (chTNT-3) directed against necrotic regions of tumors (single-stranded DNA) fused with IL-2, or GM-CSF, or TNFalphaa, or IFNgamma. Tested against different solid tumors, these reagents were found to mount an effective although transient immune response to tumor especially when used in combination. To improve upon these results, additional chTNT-3 fusion proteins using the liver-expression chemokine (LEC) and the costimulatory molecule B7.1 were constructed. Both of these reagents were found to work significantly better than the above cytokine fusion proteins due to their ability to stimulate multiple arms of the immune system deemed useful for cancer immunotherapy. Finally, the Tumor Necrosis Factor Superfamily (TNFSF) gene DC137L was used to generate chTNT-3 antibody (targeted) and soluble Fc (untargeted) fusion proteins. When used alone, both forms of costimulatory fusion proteins were found to produce in a s dose-dependent manner, complete regression of murine solid tumors. Evidence is presented to show that Treg cells play an important role in suppressing antitumor immunity since the deletion of these cells, when used in combination with LEC or costimulatory fusion proteins, produced profound and effective treatment with sustained memory. It is hoped that these data will further the preclinical development of soluble Fc and antibody based fusion proteins fro the immunotherapy of cancer.

The chemokine network. I. How the genomic organization of chemokines contains clues for deciphering their functional complexity

Chemokines are a superfamily of small structurally related cytokines that have evolved to form a complex network of proteins that typically regulate leucocyte traffic but also carry very diverse sets of immune and non-immune functions. Two general features of cytokines, redundancy and promiscuity, are particularly prominent in chemokines. In part, these properties result from repeated processes of gene duplication and diversification, which has led to the present complex genomic map of chemokines, which contains cases of non-allelic isoforms, copy number polymorphisms and classical allelic variation. This genomic complexity is compounded with pre-translational and post-translational mechanisms resulting in a complex network of proteins whose essential functions are maintained, constituting a remarkable case of robustness reminiscent of crucial metabolic pathways. This reflects the adaptation of a system under strong evolutive pressure, supporting the concept that the chemokine system is essential for the coordination, regulation and fine-tuning of the type of immune response. In this first review, we analyse currently available data on the chemokine superfamily, focusing on its complex genomic organization. Genes encoding essential inflammatory chemokines are grouped into defined chromosomal locations as clusters and miniclusters that, from the genetic point of view, can be considered single entities given their overall functions (many ligands of a cluster bind to a few shared receptors). We will try to interpret this genomic organization of chemokines in relation to the main functions acquired by each individual member or by each cluster. In a second review, we shall focus on the relationship of chemokine variability and disease susceptibility.

Remission of chronic fungal asthma in the absence of CCR8

BACKGROUND

Experimental studies have generated conflicting data regarding the role of CCR8 in antigen-driven allergic airway disease models, thereby dampening enthusiasm for further exploration of the targeting of CCR8 in asthma.

OBJECTIVE

Recent data show that the absence of CCR8 leads to a marked amplification of the innate immune response, and these data provided impetus for the current study, which addressed the role of this chemokine receptor in a model of fungal asthma.

METHODS

Wild-type (CCR8(+/+)) and CCR8-deficient (CCR8(-/-)) mice were sensitized to Aspergillus fumigatus antigens and challenged via intra-tracheal injection with live fungal conidia, and parameters of airway hyperresponsiveness, inflammation, and remodeling were examined.

RESULTS

At day 7 after conidia challenge in wild-type (CCR8(+/+)) and CCR8-deficient (CCR8(-/-)) mice sensitized to A. fumigatus antigens, markedly less fungal material was present in the lungs of the CCR8(-/-) group compared with the CCR8(+/+) group. At day 14 after conidia challenge, all characteristic airway physiology, inflammatory, and remodeling parameters of fungal asthma were significantly decreased or abolished in the CCR8(-/-) group relative to the CCR8(+/+) group.

CONCLUSION

Together these data show that an enhanced innate immune response in the absence of CCR8 promotes the rapid clearance of fungal material from the lung, thereby facilitating the remission of fungal asthma.

CLINICAL IMPLICATIONS

This study shows that the clearance of fungal material from the lung was enhanced in the absence of CCR8, which suggests that this receptor may be an attractive target in fungal-allergic asthma and other fungal-associated pulmonary diseases.

A list of candidate cancer biomarkers for targeted proteomics

We have compiled from literature and other sources a list of 1261 proteins believed to be differentially expressed in human cancer. These proteins, only some of which have been detected in plasma to date, represent a population of candidate plasma biomarkers that could be useful in early cancer detection and monitoring given sufficiently sensitive specific assays. We have begun to prioritize these markers for future validation by frequency of literature citations, both total and as a function of time. The candidates include proteins involved in oncogenesis, angiogenesis, development, differentiation, proliferation, apoptosis, hematopoiesis, immune and hormonal responses, cell signaling, nucleotide function, hydrolysis, cellular homing, cell cycle and structure, the acute phase response and hormonal control. Many have been detected in studies of tissue or nuclear components; nevertheless we hypothesize that most if not all should be present in plasma at some level. Of the 1261 candidates only 9 have been approved as "tumor associated antigens" by the FDA. We propose that systematic collection and large-scale validation of candidate biomarkers would fill the gap currently existing between basic research and clinical use of advanced diagnostics.