Regulated production and molecular diversity of human liver and activation-regulated chemokine/macrophage inflammatory protein-3 alpha from normal and transformed cells

Aquaporins (AQPs) as a marker in the physiology of inflammation and its interaction studies with garcinol

Aquaporins like AQP1, AQP3, and AQP4 are known to be involved in the pathophysiology of inflammation based on earlier reports. This study aimed to evaluate the involvement of Aquaporins as a potential target of inflammation. The study also investigates the efficacy of methanolic extract of Garcinia (GME) and its potent phytocompound (garcinol) against the Aquaporins involved in inflammation. siRNA silencing of AQP3 was carried out in RAW264.7 cells followed by LPS stimulation (1 µg/ml) and assessment of important markers of inflammation including NO, PGE2, TNF-α, IL-6, IL-1β, CCL20, iNOS and COX-2. To assess the anti-inflammatory potential of Garcinia extract and garcinol, cells were stimulated with 1 µg/ml LPS in the absence and presence of increasing concentrations of GME and garcinol. During the experimental period, extract concentrations (115 µg/ml and 230 µg/ml for RAW264.7; 118 µg/ml and 236 µg/ml for THP-1) and garcinol concentrations (6 µM and 12 µM for RAW264.7; 3 µM and 6 µM for THP-1) were selected based on the IC50. The anti-inflammatory effects were assessed by measuring the levels of TNF-α, IL-1β, IL-6, and CCL20 in LPS-stimulated cells. The AQP expression was studied at transcriptional and translational levels using qPCR and Western blot analysis respectively. AQP3 knockdown significantly decreased the NO, PGE2, TNF-α, IL-1β levels along with iNOS and COX-2 mRNA expression. LPS stimulation led to a significant increase in the mRNA and protein level expression AQP1, AQP3, and AQP4 in RAW264.7 cells; and AQP1 and AQP3 in THP-1 cells indicating their role as markers of inflammation. GME and garcinol effectively suppressed the LPS-induced proinflammatory cytokine production in both cell lines. The results indicate that AQP1, AQP3, and AQP4 could play a crucial role as markers of inflammation. Anti-inflammatory agents like Garcinia could potentially decrease the expression of such AQPs, thus inhibiting the inflammatory process.

CCL20 is a potential therapeutic target associated with immune infiltration in breast cancer

OBJECTIVES

CCL20 is a chemotactic factor that is involved in immune cell recruitment and cancer progression. However, the role of CCL20 in the prognosis of breast cancer remains unclear. This study analyzed correlations between CCL20 expression and immune infiltration, clinicopathological parameters, and prognosis in breast cancer patients.

METHODS

Correlations between CCL20 expression and clinicopathological parameters, prognosis, and immune infiltration in breast cancer were determined using the TIMER, UALCAN, and PrognoScan databases. Furthermore, gene-gene and protein-protein interactions were determined using GeneMANIA and STING network construction, respectively.

RESULTS

CCL20 expression was significantly upregulated in breast cancer and had significant associations with clinicopathological features, including race, sex, age, menopause status, cancer stage, cancer subclass, and nodal metastasis; moreover, patients with higher CCL20 expression exhibited poor prognosis. Meanwhile, CCL20 expression was significantly correlated with the infiltration of immune cells in breast cancer, including monocytes, neutrophils, tumor-associated macrophages, Th1 cells, regulatory T cells, and exhausted T cells. Moreover, the network of CCL20 expression showed the majority genes and proteins were associated with immune reactions.

CONCLUSIONS

CCL20 is a prognosis-related biomarker in breast cancer on the basis of its correlation with immune infiltration levels and has potential to also be a therapeutic target.

A chemotherapy response prediction model derived from tumor-promoting B and Tregs and proinflammatory macrophages in HGSOC

Background

Most patients with high-grade serous ovarian cancer (HGSOC) experienced disease recurrence with cumulative chemoresistance, leading to treatment failure. However, few biomarkers are currently available in clinical practice that can accurately predict chemotherapy response. The tumor immune microenvironment is critical for cancer development, and its transcriptomic profile may be associated with treatment response and differential outcomes. The aim of this study was to develop a new predictive signature for chemotherapy in patients with HGSOC.

Methods

Two HGSOC single-cell RNA sequencing datasets from patients receiving chemotherapy were reinvestigated. The subtypes of endoplasmic reticulum stress-related XBP1+ B cells, invasive metastasis-related ACTB+ Tregs, and proinflammatory-related macrophage subtypes with good predictive power and associated with chemotherapy response were identified. These results were verified in an independent HGSOC bulk RNA-seq dataset for chemotherapy. Further validation in clinical cohorts used quantitative real-time PCR (qRT-PCR).

Results

By combining cluster-specific genes for the aforementioned cell subtypes, we constructed a chemotherapy response prediction model containing 43 signature genes that achieved an area under the receiver operator curve (AUC) of 0.97 (p = 2.1e-07) for the GSE156699 cohort (88 samples). A huge improvement was achieved compared to existing prediction models with a maximum AUC of 0.74. In addition, its predictive capability was validated in multiple independent bulk RNA-seq datasets. The qRT-PCR results demonstrate that the expression of the six genes has the highest diagnostic value, consistent with the trend observed in the analysis of public data.

Conclusions

The developed chemotherapy response prediction model can be used as a valuable clinical decision tool to guide chemotherapy in HGSOC patients.

Role of Fibroblasts in Chronic Inflammatory Signalling in Chronic Rhinosinusitis with Nasal Polyps-A Systematic Review

Chronic rhinosinusitis with nasal polyps (CRSwNP) is an inflammatory disease of the nose and paranasal sinuses characterized by the presence of nasal polyps. The symptoms produced by the presence of nasal polyps such as nasal obstruction, nasal discharge, facial pain, headache, and loss of smell cause a worsening in the quality of life of patients. The source of the nasal polyps remains unclear, although it seems to be due to a chronic inflammation process in the sinonasal mucosa. Fibroblasts, the main cells in connective tissue, are intimately involved in the inflammation processes of various diseases; to this end, we carried out a systematic review to evaluate their inflammatory role in nasal polyps. Thus, we evaluated the main cytokines produced by nasal polyp-derived fibroblasts (NPDF) to assess their involvement in the production of nasal polyps and their involvement in different inflammatory pathways. The results of the review highlight the inflammatory role of NPDF through the secretion of various cytokines involved in the T1, T2, and T3 inflammatory pathways, as well as the ability of NPDF to be stimulated by a multitude of substances. With these findings, the fibroblast is positioned as a new potential therapeutic target in the treatment of CRSwNP.

MyD88-TLR4-dependent choroid plexus activation precedes perilesional inflammation and secondary brain edema in a mouse model of intracerebral hemorrhage

BACKGROUND

The functional neurological outcome of patients with intracerebral hemorrhage (ICH) strongly relates to the degree of secondary brain injury (ICH-SBI) evolving within days after the initial bleeding. Different mechanisms including the incitement of inflammatory pathways, dysfunction of the blood-brain barrier (BBB), activation of resident microglia, and an influx of blood-borne immune cells, have been hypothesized to contribute to ICH-SBI. Yet, the spatiotemporal interplay of specific inflammatory processes within different brain compartments has not been sufficiently characterized, limiting potential therapeutic interventions to prevent and treat ICH-SBI.

METHODS

We used a whole-blood injection model in mice, to systematically characterized the spatial and temporal dynamics of inflammatory processes after ICH using 7-Tesla magnetic resonance imaging (MRI), spatial RNA sequencing (spRNAseq), functional BBB assessment, and immunofluorescence average-intensity-mapping.

RESULTS

We identified a pronounced early response of the choroid plexus (CP) peaking at 12-24 h that was characterized by inflammatory cytokine expression, epithelial and endothelial expression of leukocyte adhesion molecules, and the accumulation of leukocytes. In contrast, we observed a delayed secondary reaction pattern at the injection site (striatum) peaking at 96 h, defined by gene expression corresponding to perilesional leukocyte infiltration and correlating to the delayed signal alteration seen on MRI. Pathway analysis revealed a dependence of the early inflammatory reaction in the CP on toll-like receptor 4 (TLR4) signaling via myeloid differentiation factor 88 (MyD88). TLR4 and MyD88 knockout mice corroborated this observation, lacking the early upregulation of adhesion molecules and leukocyte infiltration within the CP 24 h after whole-blood injection.

CONCLUSIONS

We report a biphasic brain reaction pattern after ICH with a MyD88-TLR4-dependent early inflammatory response of the CP, preceding inflammation, edema and leukocyte infiltration at the lesion site. Pharmacological targeting of the early CP activation might harbor the potential to modulate the development of ICH-SBI.

Innate Immune Interference Attenuates Inflammation In Bacillus Endophthalmitis

Purpose

To explore the consequences of innate interference on intraocular inflammatory responses during Bacillus endophthalmitis.

Methods

Bacillus endophthalmitis was induced in mice. Innate immune pathway activation was interfered by injecting S layer protein-deficient (∆slpA) B. thuringiensis or by treating wild-type (WT)–infected mice with a TLR2/4 inhibitor (WT+OxPAPC). At 10 hours postinfection, eyes were harvested and RNA was purified. A NanoString murine inflammation panel was used to compare gene expression in WT-infected, WT+OxPAPC, ∆slpA-infected, and uninfected eyes.

Results

In WT-infected eyes, 56% of genes were significantly upregulated compared to uninfected controls. Compared to WT-infected eyes, the expression of 27% and 50% of genes were significantly reduced in WT+OxPAPC and ∆slpA-infected eyes, respectively. Expression of 61 genes that were upregulated in WT-infected eyes was decreased in WT+OxPAPC and ∆slpA-infected eyes. Innate interference resulted in blunted expression of complement factors (C3, Cfb, and C6) and several innate pathway genes (TLRs 2, 4, 6, and 8, MyD88, Nod2, Nlrp3, NF-κB, STAT3, RelA, RelB, and Ptgs2). Innate interference also reduced the expression of several inflammatory cytokines (CSF2, CSF3, IL-6, IL-1β, IL-1α, TNFα, IL-23α, TGFβ1, and IL-12β) and chemokines (CCL2, CCL3, and CXCLs 1, 2, 3, 5, 9, and 10). All of the aforementioned genes were significantly upregulated in WT-infected eyes.

Conclusions

These results suggest that interfering with innate activation significantly reduced the intraocular inflammatory response in Bacillus endophthalmitis. This positive clinical outcome could be a strategy for anti-inflammatory therapy of an infection typically refractory to corticosteroid treatment.

Human Immune System Variation during 1 Year

The human immune system varies extensively between individuals, but variation within individuals over time has not been well characterized. Systems-level analyses allow for simultaneous quantification of many interacting immune system components and the inference of global regulatory principles. Here, we present a longitudinal, systems-level analysis in 99 healthy adults 50 to 65 years of age and sampled every third month for 1 year. We describe the structure of interindividual variation and characterize extreme phenotypes along a principal curve. From coordinated measurement fluctuations, we infer relationships between 115 immune cell populations and 750 plasma proteins constituting the blood immune system. While most individuals have stable immune systems, the degree of longitudinal variability is an individual feature. The most variable individuals, in the absence of overt infections, exhibited differences in markers of metabolic health suggestive of a possible link between metabolic and immunologic homeostatic regulation.

Qualitative and quantitative differences in endometrial inflammatory gene expression precede the development of bovine uterine disease

The transcriptome of the endometrium early postpartum was profiled to determine if inflammatory gene expression was elevated in cows which subsequently developed uterine disease. Endometrial cytobrush samples were collected at 7 days postpartum (DPP) from 112 Holstein–Friesian dairy cows, from which 27 were retrospectively chosen for RNA-seq on the basis of disease classification [ten healthy and an additional 17 diagnosed with cytological endometritis (CYTO), or purulent vaginal discharge (PVD)] at 21 DPP. 297 genes were significantly differentially expressed between cows that remained healthy versus those that subsequently developed PVD, including IL1A and IL1B (adjusted p < 0.05). In contrast, only 3 genes were significantly differentially expressed in cows which subsequently developed CYTO. Accounting for the early physiological inflammatory status present in cows which do not develop disease enhanced the detection of differentially expressed genes associated with CYTO and further expression profiling in 51 additional cows showed upregulation of multiple immune genes, including IL1A, IL1B and TNFA. Despite the expected heterogeneity associated with natural infection, enhanced activation of the inflammatory response is likely a key contributory feature of both PVD and CYTO development. Prognostic biomarkers of uterine disease would be particularly valuable for seasonal-based dairy systems where any delay to conception undermines sustainability.

Effective Method for Accurate and Sensitive Quantitation of Rapid Changes of Newly Synthesized Proteins

Protein synthesis is quickly and tightly regulated in cells to adapt to the ever-changing extracellular and intracellular environment. Accurate quantitation of rapid protein synthesis changes can provide insights into protein functions and cellular activities, but it is very challenging to achieve because of the lack of effective analysis methods. Here, we developed an effective mass spectrometry-based method named quantitative O-propargyl-puromycin tagging (QOT) by integrating O-propargyl-puromycin (OPP) labeling, bioorthogonal chemistry, and multiplexed proteomics for global and quantitative analysis of rapid protein synthesis. The current method enables us to accurately quantitate rapid changes of newly synthesized proteins because, unlike amino acids and their analogs, OPP can be utilized by the ribosome immediately without being activated and conjugated to tRNA, and thus cell starvation or pretreatment is not required. This method was applied to quantitate rapid changes of protein synthesis in THP-1 macrophages treated with lipopolysaccharide (LPS). For 15-min labeling, >3000 proteins were quantitated, and the synthesis of 238 proteins was significantly altered, including transcription factors and cytokines. The results demonstrated that protein synthesis was modulated to facilitate protein secretion in macrophages in response to LPS. Considering the importance of protein synthesis, this method can be extensively applied to investigate rapid changes of protein synthesis in the biological and biomedical research fields.

Biological Characterization of Commercial Recombinantly Expressed Immunomodulating Proteins Contaminated with Bacterial Products in the Year 2020: The SAA3 Case

The serum amyloid A (SAA) gene family is highly conserved and encodes acute phase proteins that are upregulated in response to inflammatory triggers. Over the years, a considerable amount of literature has been published attributing a wide range of biological effects to SAAs such as leukocyte recruitment, cytokine and chemokine expression and induction of matrix metalloproteinases. Furthermore, SAAs have also been linked to protumorigenic, proatherogenic and anti-inflammatory effects. Here, we investigated the biological effects conveyed by murine SAA3 (mu rSAA3) recombinantly expressed in Escherichia coli. We observed the upregulation of a number of chemokines including CCL2, CCL3, CXCL1, CXCL2, CXCL6 or CXCL8 following stimulation of monocytic, fibroblastoid and peritoneal cells with mu rSAA3. Furthermore, this SAA variant displayed potent in vivo recruitment of neutrophils through the activation of TLR4. However, a major problem associated with proteins derived from recombinant expression in bacteria is potential contamination with various bacterial products, such as lipopolysaccharide, lipoproteins and formylated peptides. This is of particular relevance in the case of SAA as there currently exists a discrepancy in biological activity between SAA derived from recombinant expression and that of an endogenous source, i.e. inflammatory plasma. Therefore, we subjected commercial recombinant mu rSAA3 to purification to homogeneity via reversed-phase high-performance liquid chromatography (RP-HPLC) and re-assessed its biological potential. RP-HPLC-purified mu rSAA3 did not induce chemokines and lacked in vivo neutrophil chemotactic activity, but retained the capacity to synergize with CXCL8 in the activation of neutrophils. In conclusion, experimental results obtained when using proteins recombinantly expressed in bacteria should always be interpreted with care.

Chicken avian β-defensin 8 modulates immune response via the mitogen-activated protein kinase signaling pathways in a chicken macrophage cell line

Defensins are antimicrobial peptides composed of 3 conserved disulfide bridges, a β-sheet, and both hydrophobic and cationic amino acids. In this study, we aimed to demonstrate the immunomodulation role of avian β-defensin 8 (AvBD8) in a chicken macrophage cell line. Chicken AvBD8 stimulated the expression of proinflammatory cytokines (IL-1β, interferon gamma, and IL-12p40) and chemokines (CCL4, CXCL13, and CCL20) in macrophages. Furthermore, by Western blotting and immunocytochemistry, we confirmed that AvBD8 activated the mitogen-activated protein kinase signaling pathway via extracellular regulated kinases 1/2 and p38 signaling molecules. Overall, AvBD8 plays a crucial role in host defense as not only an antimicrobial peptide but also an immunomodulator by activating the mitogen-activated protein kinase signaling pathway and inducing the expression of proinflammatory cytokines and chemokines.

Induction of Chemokines by Hepatitis C Virus Proteins: Synergy of the Core Protein with Interleukin-1β and Interferon-γ in Liver Bystander Cells

Chronic hepatitis C virus (HCV) infection accounts for a large proportion of hepatic fibrosis and carcinoma cases observed worldwide. Mechanisms involved in HCV-induced hepatic injury have yet to be fully elucidated. Of particular interest is the capacity of HCV to regulate inflammatory responses. Here, we reveal modulation of cytokine activity by the HCV proteins non-structural protein 3 (NS3), glycoprotein E2, and core protein for their ability to induce chemokine expression in various liver bystander cells. Chemokines sustain chronic liver inflammation and relay multiple fibrogenic effects. CCL2, CCL3, CCL20, CXCL8, and CXCL10 were differentially expressed after treatment of monocytes, fibroblasts, or liver sinusoidal microvascular endothelial cells (LSECs) with HCV proteins. In comparison to NS3 and glycoprotein E2, core protein was a stronger inducer of chemokines in liver bystander cells. Interferon-γ (IFN-γ) and interleukin-1β (IL-1β) synergized with core protein to induce CCL2, CCL20, CXCL8, or CXCL10 in fibroblasts or LSECs. These findings reveal new mechanisms of hepatic injury caused by HCV.

Serum amyloid A expression in the breast cancer tissue is associated with poor prognosis

Background

Serum amyloid A (SAA), an acute-phase protein, is expressed primarily in the liver, and recently found also expressed in cancer tissues. However, its expression and prognostic value in breast cancer have not been described.

Results

SAA protein was found expressed in tumor cells in 44.2% cases and in TAM in 62.5% cases. FISH showed more frequent SAA mRNA expression in TAM than in tumor cells (76% versus 12%, p < 0.001), and a significant association between the frequencies of SAA mRNA expression in TAM and tumor cells (r_s = 0.603, p < 0.001). The immunoreactivities of SAA protein in TAM and tumor cells were both associated with lymphovascular invasion and lymph node metastasis. Moreover, SAA-positivity in TAMs was associated with larger tumor-size, higher histological-grade, negative estrogen-receptor and progesterone-receptor statuses, and HER-2 overexpression. It was also linked to worse recurrence-free survival in a multivariable regression model.

Methods

Immunohistochemistry was applied on the tumor tissues from 208 breast cancer patients to evaluate the local SAA-protein expression with additional CD68 stain to identify the tumor-associated macrophage (TAM) on the serial tissue sections. Fluorescent in situ hybridization (FISH) was conducted on serial tissue sections from 25 of the 208 tumors to examine the expression and location of SAA mRNA.

Conclusions

Our results suggested that the TAMs may be a pivotal and main source of SAA production in tumor microenvironment of breast cancer. SAA immunoreactivity in TAM is associated with worse recurrence-free survival, and is therefore a biomarker candidate for postoperative surveillance and perhaps a therapeutic target for breast cancer.

Industrial hog farming is associated with altered circulating immunological markers

OBJECTIVES

The previously observed inverse association between hog farming and risk of lung cancer in the Agricultural Health Study (AHS) has been attributed to endotoxin exposure, the levels of which are particularly high in industrial hog confinement facilities. We conducted an investigation to explore the potential biological mechanisms underlying this association, as well as other immunological changes associated with hog farming.

METHODS

Serum immune marker levels were measured using a multiplexed bead-based assay in 61 active hog farmers and 61 controls matched on age, phlebotomy date and raising cattle. Both groups comprised non-smoking male AHS participants from Iowa. We compared natural log-transformed marker levels between hog farmers and controls using multivariate linear regression models.

RESULTS

Circulating levels of macrophage-derived chemokine (CCL22), a chemokine previously implicated in lung carcinogenesis, were reduced among hog farmers (17% decrease; 95% CI -28% to -4%), in particular for those with the largest operations (>6000 hogs: 26% decrease; 95% CI -39% to -10%; p_trend=0.002). We also found that hog farmers had elevated levels of other immune markers, including macrophage inflammatory protein-3 alpha (MIP-3A/CCL20; 111% increase, 95% CI 19% to 273%), basic fibroblast growth factor (FGF-2; 93% increase, 95% CI 10% to 240%) and soluble interleukin-4 receptor (12% increase, 95% CI 1% to 25%), with particularly strong associations for MIP-3A/CCL20 and FGF-2 in winter.

CONCLUSIONS

These results provide insights into potential immunomodulatory mechanisms through which endotoxin or other exposures associated with hog farming may influence lung cancer risk, and warrant further investigation with more detailed bioaerosol exposure assessment.

Neutrophils from Patients with Primary Ciliary Dyskinesia Display Reduced Chemotaxis to CXCR2 Ligands

Primary ciliary dyskinesia (PCD), cystic fibrosis (CF), and chronic obstructive airway disease are characterized by neutrophilic inflammation in the lungs. In CF and chronic obstructive airway disease, improper functioning of neutrophils has been demonstrated. We hypothesized that the pulmonary damage in PCD might be aggravated by abnormal functioning neutrophils either as a primary consequence of the PCD mutation or secondary to chronic inflammation. We analyzed chemotactic responses and chemoattractant receptor expression profiles of peripheral blood neutrophils from 36 patients with PCD, 21 healthy children and 19 healthy adults. We stimulated peripheral blood monocytes from patients and healthy controls and measured CXCL8 and IL-1β production with ELISA. PCD neutrophils displayed reduced migration toward CXCR2 ligands (CXCL5 and CXCL8) in the shape change, microchamber and microslide chemotaxis assays, whereas leukotriene B4 and complement component 5a chemotactic responses were not significantly different. The reduced response to CXCL8 was observed in all subgroups of patients with PCD (displaying either normal ultrastructure, dynein abnormalities or central pair deficiencies) and correlated with lung function. CXCR2 was downregulated in about 65% of the PCD patients, suggestive for additional mechanisms causing CXCR2 impairment. After treatment with the TLR ligands lipopolysaccharide and peptidoglycan, PCD monocytes produced more CXCL8 and IL-1β compared to controls. Moreover, PCD monocytes also responded stronger to IL-1β stimulation in terms of CXCL8 production. In conclusion, we revealed a potential link between CXCR2 and its ligand CXCL8 and the pathogenesis of PCD.

Inhibition of hypothalamic leukemia inhibitory factor exacerbates diet-induced obesity phenotype

Background

The consumption of large amounts of dietary fats can trigger an inflammatory response in the hypothalamus and contribute to the dysfunctional control of caloric intake and energy expenditure commonly present in obesity. The objective of this study was to identify chemokine-related transcripts that could be involved in the early stages of diet-induced hypothalamic inflammation.

Methods

We used immunoblot, PCR array, real-time PCR, immunofluorescence staining, glucose and insulin tolerance tests, and determination of general metabolic parameters to evaluate markers of inflammation, body mass variation, and glucose tolerance in mice fed a high-fat diet.

Results

Using a real-time PCR array, we identified leukemia inhibitory factor as a chemokine/cytokine undergoing a rapid increase in the hypothalamus of obesity-resistant and a rapid decrease in the hypothalamus of obesity-prone mice fed a high-fat diet for 1 day. We hypothesized that the increased hypothalamic expression of leukemia inhibitory factor could contribute to the protective phenotype of obesity-resistant mice. To test this hypothesis, we immunoneutralized hypothalamic leukemia inhibitory factor and evaluated inflammatory and metabolic parameters. The immunoneutralization of leukemia inhibitory factor in the hypothalamus of obesity-resistant mice resulted in increased body mass gain and increased adiposity. Body mass gain was mostly due to increased caloric intake and reduced spontaneous physical activity. This modification in the phenotype was accompanied by increased expression of inflammatory cytokines in the hypothalamus. In addition, the inhibition of hypothalamic leukemia inhibitory factor was accompanied by glucose intolerance and insulin resistance.

Conclusion

Hypothalamic expression of leukemia inhibitory factor may protect mice from the development of diet-induced obesity; the inhibition of this protein in the hypothalamus transforms obesity-resistant into obesity-prone mice.

Electronic supplementary material

The online version of this article (10.1186/s12974-017-0956-9) contains supplementary material, which is available to authorized users.

Computational Reconstruction of NFκB Pathway Interaction Mechanisms during Prostate Cancer

Molecular research in cancer is one of the largest areas of bioinformatic investigation, but it remains a challenge to understand biomolecular mechanisms in cancer-related pathways from high-throughput genomic data. This includes the Nuclear-factor-kappa-B (NFκB) pathway, which is central to the inflammatory response and cell proliferation in prostate cancer development and progression. Despite close scrutiny and a deep understanding of many of its members’ biomolecular activities, the current list of pathway members and a systems-level understanding of their interactions remains incomplete. Here, we provide the first steps toward computational reconstruction of interaction mechanisms of the NFκB pathway in prostate cancer. We identified novel roles for ATF3, CXCL2, DUSP5, JUNB, NEDD9, SELE, TRIB1, and ZFP36 in this pathway, in addition to new mechanistic interactions between these genes and 10 known NFκB pathway members. A newly predicted interaction between NEDD9 and ZFP36 in particular was validated by co-immunoprecipitation, as was NEDD9's potential biological role in prostate cancer cell growth regulation. We combined 651 gene expression datasets with 1.4M gene product interactions to predict the inclusion of 40 additional genes in the pathway. Molecular mechanisms of interaction among pathway members were inferred using recent advances in Bayesian data integration to simultaneously provide information specific to biological contexts and individual biomolecular activities, resulting in a total of 112 interactions in the fully reconstructed NFκB pathway: 13 (11%) previously known, 29 (26%) supported by existing literature, and 70 (63%) novel. This method is generalizable to other tissue types, cancers, and organisms, and this new information about the NFκB pathway will allow us to further understand prostate cancer and to develop more effective prevention and treatment strategies.

In molecular research in cancer it remains challenging to uncover biomolecular mechanisms in cancer-related pathways from high-throughput genomic data, including the Nuclear-factor-kappa-B (NFκB) pathway. Despite close scrutiny and a deep understanding of many of the NFκB pathway members’ biomolecular activities, the current list of pathway members and a systems-level understanding of their interactions remains incomplete. In this study, we provide the first steps toward computational reconstruction of interaction mechanisms of the NFκB pathway in prostate cancer. We identified novel roles for 8 genes in this pathway and new mechanistic interactions between these genes and 10 known pathway members. We combined 651 gene expression datasets with 1.4M interactions to predict the inclusion of 40 additional genes in the pathway. Molecular mechanisms of interaction were inferred using recent advances in Bayesian data integration to simultaneously provide information specific to biological contexts and individual biomolecular activities, resulting in 112 interactions in the fully reconstructed NFκB pathway. This method is generalizable, and this new information about the NFκB pathway will allow us to further understand prostate cancer.

The cytokine-serum amyloid A-chemokine network

Levels of serum amyloid A (SAA), a major acute phase protein in humans, are increased up to 1000-fold upon infection, trauma, cancer or other inflammatory events. However, the exact role of SAA in host defense is yet not fully understood. Several pro- and anti-inflammatory properties have been ascribed to SAA. Here, the regulated production of SAA by cytokines and glucocorticoids is discussed first. Secondly, the cytokine and chemokine inducing capacity of SAA and its receptor usage are reviewed. Thirdly, the direct (via FPR2) and indirect (via TLR2) chemotactic effects of SAA and its synergy with chemokines are unraveled. Altogether, a complex cytokine-SAA-chemokine network is established, in which SAA plays a key role in regulating the inflammatory response.

Aryl Hydrocarbon Receptor Activation Synergistically Induces Lipopolysaccharide-Mediated Expression of Proinflammatory Chemokine (c-c motif) Ligand 20

The Ah receptor (AHR) is directly involved in the regulation of both innate and adaptive immunity. However, these activities are poorly understood at the level of gene regulation. The chemokine (c-c motif) ligand 20 (CCL20) plays a nonredundant role in the chemoattraction of C-C motif receptor 6 expressing cells (eg, T cells and others). A survey of promoter regions of chemokine genes revealed that there are several putative dioxin responsive elements in the mouse Ccl20 promoter. The addition of an AHR agonist along with lipopolysaccharide (LPS) to cultured primary peritoneal macrophages results in synergistic induction of both Ccl20 mRNA and protein, compared with each compound alone. Through the use of macrophage cultures derived from Ahr(-) (/) (-) and Ahr(nls/nls) mice, it was established that expression of the AHR and its ability to translocate into the nucleus are necessary for AHR ligand-mediated synergistic induction of Ccl20. Gel shift analysis determined that a potent tandem AHR binding site ~3.1 kb upstream from the transcriptional start site can efficiently bind the AHR/ARNT (aryl hydrocarbon receptor/AHR nuclear translocator) heterodimer upon activation with a number of AHR agonists. Furthermore, studies reveal that LPS increases AHR levels on the Ccl20 promoter while decreasing HDAC1 occupancy. The level of Ccl20 constitutive expression in the colon is greatly attenuated in Ahr(-) (/) (-) mice. These studies suggest that the presence of AHR ligands during localized inflammation may augment chemokine expression, thus participating in the overall response to pathogens.

Salvianolic acid A suppresses CCL-20 expression in TNF-α-treated macrophages and ApoE-deficient mice

OBJECTIVES

The CC chemokine ligand-20 (CCL-20)/macrophage inflammatory protein-3α has been seen as one of the most important chemokines and played a key role in atherogenesis, but the mechanism that underlies the regulation of CCL-20 has not been established clearly yet. The aim of this study was to investigate the influence of salvianolic acid A (SAA) on the expression of CCL-20 in macrophages and ApoE-deficient (ApoE) mice.

METHODS

The expression of CCL-20 was detected both at protein and messenger RNA levels in RAW264.7 cells. We validated the result in ApoE mice that were intraperitoneally injected with SAA. Phosphorylation of p38 mitogen-activated protein kinase was detected with Western blot, and inhibitor of p38 was used to investigate the mechanism of regulation of CCL-20. Hematoxylin and eosin and Oil-Red-O staining were used to evaluate the atherosclerotic lesions and lipid accumulation in ApoE mice. Immunohistochemical analysis was used to detect the expressions of CCL-20 and CCR6 in the atherosclerotic lesions. Immunofluorescent analysis was used to certify the origination of CCL-20.

RESULTS

Recombinant tumor necrosis factor-α (TNF-α) upregulated CCL-20 production in dose- and time-dependent manners in RAW264.7 cells. The activity of TNF-α-induced CCL-20 production seemed to be significantly suppressed by SAA. Using p38 mitogen-activated protein kinase inhibitor, we found that p38 mediated the effects of TNF-α- and SAA-induced CCL-20 expression changes. In addition, immunohistochemical analysis of aortic root of ApoE mice also demonstrated that the expressions of CCL-20 and CCR6 were both downregulated significantly with SAA treatment. Furthermore, treatment of SAA inhibited the progression of the atherosclerotic plaques and lipid accumulation.

CONCLUSIONS

These results demonstrate that TNF-α increased but SAA suppressed CCL-20 production significantly via a novel mechanism.

Serum amyloid A chemoattracts immature dendritic cells and indirectly provokes monocyte chemotaxis by induction of cooperating CC and CXC chemokines

Serum amyloid A (SAA) is an acute phase protein that is upregulated in inflammatory diseases and chemoattracts monocytes, lymphocytes, and granulocytes via its G protein-coupled receptor formyl peptide receptor like 1/formyl peptide receptor 2 (FPRL1/FPR2). Here, we demonstrated that the SAA1α isoform also chemoattracts monocyte-derived immature dendritic cells (DCs) in the Boyden and μ-slide chemotaxis assay and that its chemotactic activity for monocytes and DCs was indirectly mediated via rapid chemokine induction. Indeed, SAA1 induced significant amounts (≥5 ng/mL) of macrophage inflammatory protein-1α/CC chemokine ligand 3 (MIP-1α/CCL3) and interleukin-8/CXC chemokine ligand 8 (IL-8/CXCL8) in monocytes and DCs in a dose-dependent manner within 3 h. However, SAA1 also directly activated monocytes and DCs for signaling and chemotaxis without chemokine interference. SAA1-induced monocyte migration was nevertheless significantly prevented (60-80% inhibition) in the constant presence of desensitizing exogenous MIP-1α/CCL3, neutralizing anti-MIP-1α/CCL3 antibody, or a combination of CC chemokine receptor 1 (CCR1) and CCR5 antagonists, indicating that this endogenously produced CC chemokine was indirectly contributing to SAA1-mediated chemotaxis. Further, anti-IL-8/CXCL8 antibody neutralized SAA1-induced monocyte migration, suggesting that endogenous IL-8/CXCL8 acted in concert with MIP-1α/CCL3. This explained why SAA1 failed to synergize with exogenously added MIP-1α/CCL3 or stromal cell-derived factor-1α (SDF-1α)/CXCL12 in monocyte and DC chemotaxis. In addition to direct leukocyte activation, SAA1 induces a chemotactic cascade mediated by expression of cooperating chemokines to prolong leukocyte recruitment to the inflammatory site.

CCR6 is a prognostic marker for overall survival in patients with colorectal cancer, and its overexpression enhances metastasis in vivo

The chemokine receptor CCR6 has been recently shown to be associated with colorectal cancer (CRC) progression. However, the direct evidence for whether CCR6 in tumors is a prognostic marker for the survival of patients with CRC and whether it plays a critical role in CRC metastasis in vivo is lacking. Here we show that the levels of CCR6 were upregulated in CRC cell lines and primary CRC clinical samples. CCR6 upregulation was closely correlated with disease stages and the survival time of CRC patients. Knockdown of CCR6 inhibited the migration of CRC cells in vitro. Overexpression of CCR6 in CRC cells increased their proliferation, migration, and colony formation in vitro and promoted their metastatic potential in vivo. CCR6 activated Akt signaling, upregulated metastasis genes and downregulated metastasis suppressor genes. Selective targeting of CCR6 in tumors dramatically inhibited the growth of CRC in mice. Thus, the tumor expression of CCR6 plays a critical role in CRC metastasis, upregulated CCR6 predicts poor survival in CRC patients, and targeting CCR6 expression in tumors may be a potential therapeutic strategy for CRC.

Chemokines and cytokines as salivary biomarkers for the early diagnosis of oral cancer

Chemokines have been shown to be important in both inflammation and carcinogenesis and are able to be measured in saliva with relatively robust methods including enzyme-linked immunosorbent assays (ELISA). Thus it has been hypothesized that patients with oral cancer and oral potentially malignant lesions will have elevated levels of specific chemokines in oral fluids and that this may be used as a marker of both the early detection of malignant disease and progression to malignancy. The concept that salivary biomarkers can be easily measured and indicate disease states has profound consequences for clinical practice and may open up new strategies for the diagnosis, prognosis, and potential therapy of oral squamous cell carcinoma (OSCC). This review focuses on our understanding of cytokines and chemokines and the potential role that they may have in clinical practice.

Potential contribution of saliva to the sexual transmission of HIV through the secretion of CCL20 by genital epithelial cells

Saliva can be considered as an important actor during sexual intercourse. However, there is no data concerning its influence on HIV sexual transmission. The aim of this study was to evaluate the role of whole saliva on the in vitro secretion of CCL20 by monolayered HEC-1A endocervical epithelium cells. HEC-1A cells were cultivated in 96-well microplates and incubated with specimens of whole saliva collected from 57 subjects tested seropositive (n = 34) or seronegative (n = 23) for HIV and presenting different oral conditions (healthy periodontally, n = 22, and gingivitis/periodontitis, n = 35). The production of CCL20 in the supernatants of HEC-1A cells after overnight incubation at 37°C was quantified using ELISA. The salivary concentration of lactoferrin (Lf) and IL-1β was tested by ELISA. Saliva samples were found able to stimulate dramatically the production of CCL20 by epithelial cells, increasing this synthesis by a mean factor of 38.1 with reference to untreated cells. This stimulation was equivalent to that observed with IL-1β used as positive control. Although no difference was observed according to oral condition, HIV status or salivary concentration of Lf and IL-1β, the high salivary concentration of the latter protein could acknowledge in large part for the overproduction of CCL20 by HEC-1A cells when stimulated by saliva. Saliva was shown to significantly increase CCL20 secretion and may be responsible for an enhanced recruitment of dendritic/Langerhans cells at the genital level. These results suggest that saliva could facilitate HIV entry and possibly other pathogens through the genital mucosa during heterosexual intercourse.

Characterization of the molecular interplay between Moraxella catarrhalis and human respiratory tract epithelial cells

Moraxella catarrhalis is a mucosal pathogen that causes childhood otitis media and exacerbations of chronic obstructive pulmonary disease in adults. During the course of infection, M. catarrhalis needs to adhere to epithelial cells of different host niches such as the nasopharynx and lungs, and consequently, efficient adhesion to epithelial cells is considered an important virulence trait of M. catarrhalis. By using Tn-seq, a genome-wide negative selection screenings technology, we identified 15 genes potentially required for adherence of M. catarrhalis BBH18 to pharyngeal epithelial Detroit 562 and lung epithelial A549 cells. Validation with directed deletion mutants confirmed the importance of aroA (3-phosphoshikimate 1-carboxyvinyl-transferase), ecnAB (entericidin EcnAB), lgt1 (glucosyltransferase), and MCR_1483 (outer membrane lipoprotein) for cellular adherence, with ΔMCR_1483 being most severely attenuated in adherence to both cell lines. Expression profiling of M. catarrhalis BBH18 during adherence to Detroit 562 cells showed increased expression of 34 genes in cell-attached versus planktonic bacteria, among which ABC transporters for molybdate and sulfate, while reduced expression of 16 genes was observed. Notably, neither the newly identified genes affecting adhesion nor known adhesion genes were differentially expressed during adhesion, but appeared to be constitutively expressed at a high level. Profiling of the transcriptional response of Detroit 562 cells upon adherence of M. catarrhalis BBH18 showed induction of a panel of pro-inflammatory genes as well as genes involved in the prevention of damage of the epithelial barrier. In conclusion, this study provides new insight into the molecular interplay between M. catarrhalis and host epithelial cells during the process of adherence.

Recruitment of CCR6-expressing Th17 cells by CCL20 secreted from plasmin-stimulated macrophages

In the present study, monocyte-derived human macrophages were differentiated from buffy coats. Naïve CD4⁺ T-cells enriched from peripheral blood mononuclear cells using anti-CD4 magnetic beads and the autoMACS separation system were polarized under T-helper 17 (Th17)-promoting conditions for 6 days to get Th17 cells. The frequency of Th17 cell differentiation and the expression of C-C chemokine receptor type 6 (CCR6) on Th17 cells were investigated by flow cytometry. Plasmin-triggered induction of macrophage inflammatory protein-3alpha/C-C chemokine ligand 20 (CCL20) genes in macrophages was assessed by reverse transcription-polymerase chain reaction, and secreted protein levels were measured by enzyme-linked immunosorbent assay. Th17 cell migration induced by CCL20 secreted from plasmin-stimulated macrophages was tested in vitro by chemotaxis using a transwell system. These results demonstrate that plasmin triggers the expression of chemokine CCL20 messenger RNA and the release of CCL20 protein in human monocyte-derived macrophages, which critically depend on the proteolytic activity of plasmin and activation of p38 mitogen-activated protein kinase and nuclear factor-kappaB signaling pathways. Expression of CCR6 was detected on 87.23 ± 8.6% of Th17 cells in vitro. Similar to chemotaxis triggered by recombinant human CCL20, supernatants collected from plasmin-stimulated macrophage-induced chemotactic migration of Th17 cells, which could be inhibited by an anti-CCL20 neutralizing antibody. These results suggest that plasmin generated in inflamed tissues might elicit production of chemokine CCL20 by human macrophages leading to the recruitment of CCR6 positive Th17 cells to the inflammatory sites.

Human papillomavirus type 8 interferes with a novel C/EBPβ-mediated mechanism of keratinocyte CCL20 chemokine expression and Langerhans cell migration

Infection with genus beta human papillomaviruses (HPV) is implicated in the development of non-melanoma skin cancer. This was first evidenced for HPV5 and 8 in patients with epidermodysplasia verruciformis (EV), a genetic skin disease. So far, it has been unknown how these viruses overcome cutaneous immune control allowing their persistence in lesional epidermis of these patients. Here we demonstrate that Langerhans cells, essential for skin immunosurveillance, are strongly reduced in HPV8-positive lesional epidermis from EV patients. Interestingly, the same lesions were largely devoid of the important Langerhans cells chemoattractant protein CCL20. Applying bioinformatic tools, chromatin immunoprecipitation assays and functional studies we identified the differentiation-associated transcription factor CCAAT/enhancer binding protein β (C/EBPβ) as a critical regulator of CCL20 gene expression in normal human keratinocytes. The physiological relevance of this finding is supported by our in vivo studies showing that the expression patterns of CCL20 and nuclear C/EBPβ converge spatially in the most differentiated layers of human epidermis. Our analyses further identified C/EBPβ as a novel target of the HPV8 E7 oncoprotein, which co-localizes with C/EBPβ in the nucleus, co-precipitates with it and interferes with its binding to the CCL20 promoter in vivo. As a consequence, the HPV8 E7 but not E6 oncoprotein suppressed C/EBPβ-inducible and constitutive CCL20 gene expression as well as Langerhans cell migration. In conclusion, our study unraveled a novel molecular mechanism central to cutaneous host defense. Interference of the HPV8 E7 oncoprotein with this regulatory pathway allows the virus to disrupt the immune barrier, a major prerequisite for its epithelial persistence and procarcinogenic activity.

Caffeic acid phenethyl ester causes p21 induction, Akt signaling reduction, and growth inhibition in PC-3 human prostate cancer cells

Caffeic acid phenethyl ester (CAPE) treatment suppressed proliferation, colony formation, and cell cycle progression in PC-3 human prostate cancer cells. CAPE decreased protein expression of cyclin D1, cyclin E, SKP2, c-Myc, Akt1, Akt2, Akt3, total Akt, mTOR, Bcl-2, Rb, as well as phosphorylation of Rb, ERK1/2, Akt, mTOR, GSK3α, GSK3β, PDK1; but increased protein expression of KLF6 and p21(Cip1). Microarray analysis indicated that pathways involved in cellular movement, cell death, proliferation, and cell cycle were affected by CAPE. Co-treatment of CAPE with chemotherapeutic drugs vinblastine, paclitaxol, and estramustine indicated synergistic suppression effect. CAPE administration may serve as a potential adjuvant therapy for prostate cancer.

Host immune-related gene responses against highly pathogenic avian influenza virus infection in vitro differ among chicken cell lines established from different organs

Highly pathogenic avian influenza virus (HPAIV) induces acute disease in chickens causing high mortality and morbidity and is a major threat to poultry industries in Southeast Asian countries. The mechanisms of disease manifestation and host innate immune responses against HAPIV in chickens are not well understood. In this study, we examined virus replication and host gene expressions in four chicken cell lines in vitro to elucidate the impact of host innate immune responses against viral replication. It was demonstrated that viral replication efficiencies were different depending on the cell line. The viral replication appeared to be affected by the basal expression of IFN related genes. The expression of immune-related genes against the viral infection also varied in a cell line dependent manner. In non-immune derived cell lines, but not in immune derived cell lines, the expression of the CCL5 and CCL20 genes were induced by HPAIV infection. Reverse genetics HPAIV, with internal genes from avirulent avian influenza, reduced virus replication and affected immune-related gene expression in a cell line dependent manner. These results suggest the possibility that differential immune responses in different cell types in local tissues could modulate the consequences of HPAIV infection in chickens.

OX40 induces CCL20 expression in the context of antigen stimulation: an expanding role of co-stimulatory molecules in chemotaxis

OX40 is an inducible co-stimulatory molecule expressed by activated T cells. It plays an important role in the activation and proliferation of T lymphocytes. Recently, some co-stimulatory molecules have been shown to direct leukocyte trafficking. Chemotaxis is essential for achieving an effective immune response. CCL20 is an important chemoattractant produced by activated T cells. In this study, using DO11.10 mice whose transgenic T cell receptor specifically recognizes ovalbumin, we demonstrate that ovalbumin induces OX40 expression in CD4+ lymphocytes. Further stimulation of OX40 by OX40 activating antibody up-regulates CCL20 production. Both NF-kappaB dependent and independent signaling pathways are implicated in the induction of CCL20 by OX40. Finally, we primed the DO11.10 splenocytes with or without OX40 activating antibody in the presence of ovalbumin. Intranasal administration of the cell lysates derived from the cells with OX40 stimulation results in more severe leukocyte infiltration in the lung of DO11.10 mice, which is substantially attenuated by CCL20 blocking antibody. Taken together, this study has shown that activation of OX40 induces CCL20 expression in the presence of antigen stimulation. Thus, our results broaden the role of OX40 in chemotaxis, and reveal a novel effect of co-stimulatory molecules in orchestrating both T cell up-regulation and migration.

CC chemokine ligand-2 synergizes with the nonchemokine G protein-coupled receptor ligand fMLP in monocyte chemotaxis, and it cooperates with the TLR ligand LPS via induction of CXCL8

During inflammatory reactions, endogenously produced cytokines and chemokines act in a network and interact with hormones and neurotransmitters to regulate host immune responses. These signaling circuitries are even more interfaced during infections, when microbial agonists activate TLR, RLR, and NLR receptors. On the basis of the discovery of synergy between chemokines for neutrophil attraction, we extend here this phenomenon between the chemokine MCP-1/CCL2 and the GPCR ligand fMLP or the TLR4 agonist LPS on monocytes. In fact, the bacterial tripeptide fMLP, but not the cytokines IL-1beta or IFN-gamma, significantly and dose-dependently synergized with CCL2 in monocyte chemotaxis. Furthermore, LPS rapidly induced the expression of IL-8/CXCL8 but not of the CCL2 receptor CCR2 in monocytic cells. In turn, the induced CXCL8 synergized with CCL2 for mononuclear cell chemotaxis, and the chemotactic effect was mediated by CXCR1/CXCR2, because CXCL8 receptor antagonists or antibodies were capable of blocking the synergy, while keeping the responsiveness to CCL2 intact. These data recapitulate in vitro the complexity of innate immune regulation, provide a novel mechanism of enhancing monocyte chemotaxis during bacterial infections with gram-negative bacteria and demonstrate the importance of local contexts in inflammatory and infectious insults.

Inhibition of CCR6 function reduces the severity of experimental autoimmune encephalomyelitis via effects on the priming phase of the immune response

Chemokines are essential for homeostasis and activation of the immune system. The chemokine ligand/receptor pairing CCL20/CCR6 is interesting because these molecules display characteristics of both homeostatic and activation functions. These dual characteristics suggest a role for CCR6 in the priming and effector phases of the immune response. However, while CCR6 has been implicated in the effector phase in several models, a role in the priming phase is less clear. Herein we analyze the role of CCR6 in these two important arms of the immune response during experimental autoimmune encephalomyelitis (EAE). Both CCR6 and its chemokine ligand CCL20 were up-regulated in the draining lymph nodes and spinal cord during EAE, and CCR6 was up-regulated on CD4(+) T cells that had divided following induction of EAE. The functional role of this expression was demonstrated by impaired development of EAE in gene-targeted CCR6-deficient mice and in mice treated either with a neutralizing anti-CCR6 Ab or with a novel receptor antagonist. Inhibition of EAE was due to reduced priming of autoreactive CD4(+) T cells probably as a result of impaired late-stage influx of dendritic cells into draining lymph nodes. This was accompanied by reduced egress of activated lymphocytes from the lymph nodes. These results demonstrate a novel role for CCR6 in the mechanism of autoreactive lymphocyte priming and emigration to the efferent lymphatics.

Serum amyloid A induces CCL20 secretion in mononuclear cells through MAPK (p38 and ERK1/2) signaling pathways

Although the serum levels of SAA had been reported to be upregulated during inflammatory/infectious process, the role of this acute-phase protein has not been completely elucidated. In previous studies, we demonstrated that SAA stimulated the production of TNF-alpha, IL-1beta, IL-8, NO, and ROS by neutrophils and/or mononuclear cells. Herein we demonstrate that SAA induces the expression and release of CCL20 from cultured human blood mononuclear cells. We also focus on the signaling pathways triggered by SAA. In THP-1 cells SAA promotes phosphorylation of p38 and ERK1/2. Furthermore, the addition of SB203580 (p38 inhibitor) and PD98059 (ERK 1/2 inhibitor) inhibits the expression and release of CCL20 in mononuclear cells treated with SAA. Our results point to SAA as an important link of innate to adaptive immunity, once it might act on the recruitment of mononuclear cells.

The expression of E-selectin and chemokines in the cultured human lymphatic endothelium with lipopolysaccharides

This study investigated the expression of selectins and chemokines in cultured human lymphatic endothelial cells stimulated with lipopolysaccharides. In microarray, vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 gene expressions in the lymphatic endothelium with lipopolysaccharides did not change at 0.5 h but increased two- to three-fold at 12 h, whereas E-selectin increased 10-fold at 0.5 h and 68-fold at 12 h compared with untreated cells. The E-selectin mRNA and protein increased in the lymphatic endothelial cells with lipopolysaccharides at more than two-fold levels compared with human umbilical vein endothelial cells. Induction of Cys-Cys chemokine ligand 2, 3, 5, 7, 8 and 20 mRNAs in the lymphatic endothelial cells with lipopolysaccharides was detected in microarray and real-time PCR. The Cys-Cys chemokine ligand 2, 5 and 20 mRNA amounts in cells with high concentration lipopolysaccharides were larger in the lymphatic endothelial cells than in human umbilical vein endothelial cells. The Cys-Cys chemokine ligand 3 and 8 mRNAs were not detected in human umbilical vein endothelial cells. Induction of Cys-X-Cys chemokine ligand 1, 3, 5, 6 and 8 mRNAs was detected in the lymphatic endothelial cells with lipopolysaccharides. The Cys-X-Cys chemokine ligand 3, 5 and 8 mRNA amounts in cells with high concentration lipopolysaccharides were larger in the lymphatic endothelial cells than in human umbilical vein endothelial cells. In conclusion, it was demonstrated that the cultured human lymphatic endothelial cells express E-selectin and phagocyte-attractive chemokine genes.

Effect of radiation on gene expression of rat liver chemokines: in vivo and in vitro studies

The aim of the study was to analyze the effect of a single irradiation on chemokine gene expression in the rat liver and in isolated rat hepatocytes. RNA extracted from livers and from hepatocytes within the first 48 h after irradiation was analyzed by real-time PCR and the Northern blot assay. The chemokine concentrations in the serum of irradiated rats were measured quantitatively by ELISA. A significant radiation-induced increase of CINC1, IP10, MCP1, MIP3alpha, MIP3beta, MIG and ITAC gene expression could be detected at the RNA level in the liver. CINC1, MCP1 and IP10 serum levels were significantly increased. In rat hepatocytes in vitro, only MIP3alpha showed a radiation-induced increase in expression, while CINC1, IP10, MIP3beta, MIG, MIP1alpha, ITAC and SDF1 RNA levels were significantly down-regulated. However, incubation of irradiated hepatocytes in vitro with either TNF-alpha, IL1beta, or IL6 plus TNF-alpha led to up-regulation of MCP1, IP10 and MCP1 or CINC1 and MIP3beta, respectively. Irradiation of the liver induces up-regulation of the genes of the main proinflammatory chemokines, probably through the action of locally synthesized proinflammatory cytokines. The reason for the lack of liver inflammation in this model has still to be clarified.

Exodus-1 (CCL20): evidence for the participation of this chemokine in spontaneous labor at term, preterm labor, and intrauterine infection

AIM

CCL20, also known as MIP-3 alpha, is a chemokine that participates in chemotaxis of immature dendritic cells, effector/memory T-cells, and B-lymphocytes. The objectives of this study were to determine whether CCL20 can be detected in amniotic fluid (AF) and if AF concentration of this chemokine changes with advancing gestational age, parturition (term and preterm), and intra-amniotic infection/inflammation (IAI).

METHODS

A cross-sectional study was conducted including the following groups: (1) mid-trimester of pregnancy (n=65); (2) term not in labor (TNL; n=22); (3) term in labor (TIL; n=47); (4) spontaneous preterm labor (PTL) who delivered at term (n=57); (5) spontaneous PTL without IAI who delivered preterm (n=71); and (6) spontaneous PTL with IAI (n=38). AF CCL20 concentrations were determined using ELISA.

RESULTS

(1) The median AF CCL20 concentration in TNL was higher than that of mid-trimester patients; (2) Women in spontaneous labor at term had a higher median AF concentration of CCL20 than patients at term not in labor; (3) Patients with spontaneous PTL and IAI had a significantly higher median AF concentration of CCL20 than those without IAI who delivered preterm and those who delivered at term. Moreover, women with spontaneous PTL without IAI who delivered preterm had a significantly higher median AF concentration than those with PTL who subsequently delivered at term.

CONCLUSIONS

(1) CCL20 is a physiologic constituent of AF and its concentration increases as term approaches; (2) spontaneous labor (term and preterm) in the absence of IAI is associated with increased bioavailability of AF CCL20 suggesting that an increase in CCL20 is part of the common pathway of human parturition; (3) patients with IAI had dramatic elevations in the AF CCL20 concentrations suggesting that this chemokine participates in the host response to infection or other stimuli associated with intra-amniotic infection.

Hypoxia transcriptionally induces macrophage-inflammatory protein-3alpha/CCL-20 in primary human mononuclear phagocytes through nuclear factor (NF)-kappaB

Hypoxia, a condition of low oxygen tension, occurring in many pathological processes, modifies the mononuclear phagocyte transcriptional profile. Here, we demonstrate hypoxic up-regulation of the CCL20 chemokine in primary human monocytes (Mn) and macrophages. mRNA induction was paralleled by protein secretion and dependent on gene transcription activation. Functional studies of the CCL20 promoter using a series of 5'-deleted and mutated reporter constructs demonstrated the requirement for the NF-kappaB-binding site located at position -92/-82 for gene transactivation by hypoxia, as 1) transcription was abrogated by a 3-bp mutation of the NF-kappaB motif; 2) three copies of the wild-type NF-kappaB-binding site conferred hypoxia responsiveness to a minimal heterologous promoter; and 3) hypoxia increased specific NF-kappaB binding to this sequence. Furthermore, we provide evidence of the specific role of a single NF-kappaB family member, p50, in mediating CCL20 gene transcription in hypoxic Mn. p50 homodimers were the only detectable NF-kappaB complexes binding the cognate kappaB site on the CCL20 promoter upon hypoxia exposure, and NF-kappaBp50 knockdown by lentiviral-mediated short hairpin RNA interference resulted in complete binding inhibition. NF-kappaBp50 overexpression in transient cotransfection studies promoted CCL20 gene transactivation, which was abrogated by mutation of the -92/-82 kappaB site. Moreover, nuclear expression of the other NF-kappaB family members was inhibited in hypoxic Mn. In conclusion, this study characterizes a previously unrecognized role for hypoxia as a transcriptional inducer of CCL20 in human mononuclear phagocytes and highlights the importance of the NF-kappaB pathway in mediating this response, with potential implications for inflammatory disease and cancer pathogenesis.

Substance P regulates macrophage inflammatory protein 3alpha/chemokine C-C ligand 20 (CCL20) with heme oxygenase-1 in human periodontal ligament cells

Although substance P (SP), a potent proinflammatory peptide, is involved in inflammation and immune responses, the effect of SP on the expression of macrophage inflammatory protein 3alpha[MIP-3alpha, chemokine C-C ligand 20 (CCL20)] in periodontal ligament (PDL) cells is unknown. Equally enigmatic is the link between SP, the stress protein heme oxygenase-1 (HO-1), and CCL20 production. We investigated whether SP induces the release of chemokine CCL20 from immortalized PDL (IPDL) cells, and further clarify SP-mediated pathways. We also examined the relationship between HO-1 and CCL20 by treating PDL cells with SP. Incubating IPDL cells with SP increased expression of CCL20 mRNA and CCL20 protein in a dose-time-dependent manner. Highly selective p38 and extracellular-regulated kinase 1/2 (ERK1/2) inhibitors abrogated SP-induced expression of CCL20 in IPDL cells. SP is also responsible for initiating phosphorylation of IkappaB, degradation of IkappaB and activation of nuclear factor (NF)-kappaB. SP induced expression of HO-1 in both a concentration- and time-dependent manner, and CCL20 reflected similar patterns. The inductive effects of SP on HO-1 and CCL20 were enhanced by HO-1 inducer hemin and the membrane-permeable guanosine 3',5'-monophosphate (cGMP) analogue 8-bromo-cGMP. Conversely, this pathway was inhibited by the HO-1 inhibitor zinc protoporphyrin IX (ZnPP IX) and the selective inhibitor of guanylate cyclase, 1H-(1,2,4)oxadiazole(4,3-a)quinoxalin-1-one (ODQ). We report herein the pathway that connects SP along with other modulators of neuroimmunoregulation to the induction of HO-1 and the inflammatory mediator macrophage inflammatory protein (MIP)-3alpha/CCL20 in IPDL cells, which play an important role in the development of periodontitis or inflammation during orthodontic tooth movement.

Etanercept reduces the serum levels of interleukin-23 and macrophage inflammatory protein-3 alpha in patients with rheumatoid arthritis

The purpose of this study was to analyze the effect of the soluble TNF-alpha receptor etanercept on the serum levels of IL-16, IL-17, IL-23, and macrophage inflammatory protein-3alpha (MIP-3alpha) in rheumatoid arthritis (RA) patients. Twenty-two patients with RA were administered etanercept once or twice a week for more than 6 months, and we evaluated clinical and laboratory parameters and serum levels of IL-16, IL-17, IL-23, and MIP-3alpha at the baseline and at 3 and 6 months. Additionally, the production of IL-23 and MIP-3alpha of cultured synovial cells stimulated with TNF-alpha from RA patients was determined by ELISA. We also used ELISA kits to determine synovial fluid (SF) levels of IL-17, IL-23, and MIP-3alpha in patients with RA, osteoarthritis (OA), pseudogouty arthritis (PGA), and gouty arthritis (GA). A significant decrease in serum levels of IL-23 and MIP-3alpha was observed at 3 and 6 months after initial treatment of etanercept. TNF-alpha induced MIP-3alpha but not IL-23 production in cultured synovial cells from RA patients. SF levels of IL-17, IL-23, and MIP-3alpha in RA patients showed significantly higher levels than those of OA, PGA, and GA patients. This study demonstrated that the reduction of IL-23 and MIP-3alpha production in RA patients was a newly determined function of etanercept.

Expression of the chemokine receptor CCR6 in the Lewis lung carcinoma (LLC) cell line reduces its metastatic potential in vivo

Chemokines and their receptors play important roles in various aspects of tumoral processes, and evidence was provided for their critical involvement in determining the metastatic destination of tumor cells. Here, we analyzed in vitro and in vivo, how CCR6 expression could alter the behavior of Lewis lung carcinoma (LLC) cells, which were shown to express low levels of the CCR6 ligand, CCL20 (LARC), both in vitro and in vivo. The expression of CCR6 significantly decreased the number of metastases in immunocompetent C57BL/6 mice, without affecting the tumor-forming ability of LLC cells. This was correlated with a decrease in clonogenicity in soft and hard agar, and with increased adhesion to type-IV collagen. These two observations made in basal conditions were enhanced when CCL20 was added to the assay medium. Thus, expression of CCR6 in tumor cells, associated with the local production of CCL20, decreased the metastatic potential of the LLC line. We propose a model, in which the expression of a chemokine receptor in tumor cells can act as a metastasis-suppressor, or a metastasis-promoting factor, according to the expression, or the absence of expression of the cognate ligand(s) in the tumor.

Protective immunity and delayed type hypersensitivity reaction are uncoupled in experimental Leishmania major infection of CCR6-negative mice

The chemokine receptor CCR6 is expressed on naïve B cells, dendritic cell and T-cell subpopulations and is involved in cell navigation during organogenesis and recruitment in response to inflammatory stimuli. Gene-deficient C57BL/6 CCR6(-/-) mice infected with the protozoan parasite Leishmania (L.) major were able to mount a protective immune response and survived the infection. Whereas macrophage production of nitric oxide (NO), the key leishmanicidal effector molecule during the immune response to L. major, did not require CCR6, the migration of CD4(+) T cells to the site of infection was reduced in CCR6(-/-) mice. Furthermore, the induction of a T-cell-dependent delayed-type-hypersensitivity (DTH) reaction was defective in CCR6(-/-) mice, whereas resistance to re-infection was maintained in the absence of CCR6. We conclude that CCR6 contributes to the recruitment of T cells to the site of infection, but is largely dispensable for the control of L. major parasites during primary or secondary infection.

Natural post-translational modifications of chemokines

Chemokines, adhesion molecules, cytokines and proteases regulate the extravasation of leucocytes during acute and chronic inflammation and leucocyte homing. Chemokines are produced after transcriptional activation by inflammatory mediators such as cytokines or microbial Toll-like receptor ligands and their effect depends on the expression of chemokine receptors on specific cell types. More and more evidence points towards a role for post-translational modifications in the fine-tuning of chemokine activity. Although both glycosylation and proteolytic processing of the C- and/or N-terminus of chemokines has been reported, mainly proteolytic processing of the N-terminus appears to affect the receptor specificity, chemotactic property and signalling potency of these low-molecular-mass proteins. N-terminal processing of chemokines by aminopeptidases or endoproteases may alter the receptor specificity and may result in up- or down-regulation of their chemotactic, antiviral or angiogenic activity.

Effect of oestradiol on PAMP-mediated CCL20/MIP-3 alpha production by mouse uterine epithelial cells in culture

The present study was undertaken to establish whether mouse uterine epithelial cells produce CCL20/macrophage inflammatory protein 3 alpha (CCL20/MIP-3 alpha) and to determine whether secretion is under hormonal control and influenced by pathogen-associated molecular patterns (PAMPs). In the absence of PAMPs, polarized uterine epithelial cells grown to confluence on cell culture inserts constitutively secreted CCL20/MIP-3 alpha with preferential accumulation into the apical compartment. When epithelial cells were treated with the Toll-like receptor (TLR) agonists Pam3Cys (TLR2/1), peptidoglycan (TLR2/6) or lipopolysaccharide (LPS; TLR4), CCL20/MIP-3 alpha increased rapidly (4 hr) in both apical and basolateral secretions. Time-course studies indicated that responses to PAMPs added to the apical surface persisted for 12-72 hr. Stimulation with loxoribin (TLR7) and DNA CpG motif (TLR9) increased basolateral but not apical secretion of CCL20/MIP-3 alpha. In contrast, the viral agonist Poly(I:C) (TLR3) had no effect on either apical or basolateral secretion. In other studies, we found that oestradiol added to the culture media decreased the constitutive release of CCL20/MIP-3 alpha. Moreover, when added to the culture media along with LPS, oestradiol inhibited LPS-induced increases in CCL20/MIP-3 alpha secretion into both the apical and basolateral compartments. In summary, these results indicate that CCL20/MIP-3 alpha is produced in response to PAMPs. Since CCL20/MIP-3 alpha is chemotactic for immature dendritic cells, B cells and memory T cells and has antimicrobial properties, these studies suggest that CCL20/MIP-3 alpha production by epithelial cells, an important part of the innate immune defence in the female reproductive tract, is under hormonal control and is responsive to microbial challenge.

Function of Liver Activation-Regulated Chemokine/CC Chemokine Ligand 20 Is Differently Affected by Cathepsin B and Cathepsin D Processing

Chemokine processing by proteases is emerging as an important regulatory mechanism of leukocyte functions and possibly also of cancer progression. We screened a large panel of chemokines for degradation by cathepsins B and D, two proteases involved in tumor progression. Among the few substrates processed by both proteases, we focused on CCL20, the unique chemokine ligand of CCR6 that is expressed on immature dendritic cells and subtypes of memory lymphocytes. Analysis of the cleavage sites demonstrate that cathepsin B specifically cleaves off four C-terminally located amino acids and generates a CCL20(1-66) isoform with full functional activity. By contrast, cathepsin D totally inactivates the chemotactic potency of CCL20 by generating CCL20(1-55), CCL20(1-52), and a 12-aa C-terminal peptide CCL20(59-70). Proteolytic cleavage of CCL20 occurs also with chemokine bound to glycosaminoglycans. In addition, we characterized human melanoma cells as a novel CCL20 source and as cathepsin producers. CCL20 production was up-regulated by IL-1alpha and TNF-alpha in all cell lines tested, and in human metastatic melanoma cells. Whereas cathepsin D is secreted in the extracellular milieu, cathepsin B activity is confined to cytosol and cellular membranes. Our studies suggest that CCL20 processing in the extracellular environment of melanoma cells is exclusively mediated by cathepsin D. Thus, we propose a model where cathepsin D inactivates CCL20 and possibly prevents the establishment of an effective antitumoral immune response in melanomas.

Increase of CCL20 expression by human gingival fibroblasts upon stimulation with cytokines and bacterial endotoxin

We have demonstrated recently that CCL20 was expressed in periodontal diseased tissues and abundant CCR6 positive T cells infiltrated in periodontally diseased tissue. However, it is uncertain which cells can elicit CCL20 production. In the present study, we examined the properties of CCL20 production by human gingival fibroblasts (HGF) culture. Here, we report that interleukin-1 beta (IL-1beta), tumour necrosis factor-alpha (TNF-alpha) and Escherichia coli lipopolysaccharide (LPS) can significantly induce the production of CCL20 by HGF. We found that TNF-alpha and E. coli LPS enhanced the production of CCL20 by HGF treated with IL-1beta. In contrast, interferon-gamma (IFN-gamma) dramatically diminished CCL20 production induced by IL-1beta. Moreover, we demonstrated that nuclear factor-kappaB (NF-kappaB), p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinases (ERK) play an important role in mediating the production of CCL20 induced by IL-1beta and TNF-alpha. On the other hand, we found that not only NF-kappaB, p38 MAPK and ERK but also c-Jun NH2-terminal kinase (JNK) are involved in CCL20 production induced by E. coli LPS. Finally, we found that HGF express CCR6, CCL20 receptor, and CCL20 induced vascular endothelial growth factor (VEGF) by HGF. Taken together, these findings that HGF will be a source of CCL20 in periodontal tissue, and the CCL20 production will be controlled by proinflammatory cytokine and bacterial LPS in periodontally diseased tissue. Thus, CCL20 by HGF might be involved in inflammatory cells infiltration, and promote the progression of periodontal disease.

Physiological Role of Macrophage Inflammatory Protein-3α Induction during Maturation of Intestinal Macrophages

Intestinal macrophages (IMAC) are a central component in the defense of the intestinal mucosa against luminal microbes. In normal mucosa, monocytes differentiate to immunologically tolerant IMAC with a typical phenotype lacking activation markers such as CD14 and TLRs 2 and 4. CD33+ IMAC were isolated from normal intestinal mucosa by immunomagnetic beads. A subtractive hybridization subtracting mRNA from normal IMAC from those of in vitro differentiated macrophages was performed. IMAC differentiation was studied in multicellular spheroids (MCS). Functional assays on migration of CD45R0+ T cells were performed in MCS coculture models. Of 76 clones, 3 obtained by subtractive mRNA hybridization showed >99% homology to mRNA of MIP-3alpha, indicating that this chemokine is induced in IMAC compared with in vitro differentiated macrophages. MIP-3alpha protein expression was confirmed in cryostat sections of normal intestinal mucosa by immunohistochemistry. IMAC in the lamina propria stained positive for MIP-3alpha. FACS of purified IMAC clearly indicated expression of MIP-3alpha in these cells. In the MCS-in vitro differentiation model for IMAC, MIP-3alpha protein expression was absent on day 1 but detectable on day 7 of coculture, demonstrating the induction of MIP-3alpha during differentiation of IMAC. IMAC attracted CD45R0+ T cells to migrate into an MCS coculture model. In human mucosa, a close contact between IMAC and CD45R0+ T cells could be demonstrated. MIP-3alpha is induced during the differentiation of monocytes into IMAC. Our data suggest that MIP-3alpha expression could be involved in the recruitment of CD45R0+ cells into the lamina propria.

Analysis of Interleukin-Activated Human Gingival Fibroblasts: Modulation of Chemokine Responses by Female Hormones

BACKGROUND

The female sex hormones are known to affect the response of numerous tissues to an immune challenge. Because such hormones normally fluctuate during puberty, pregnancy, and the menstrual cycle, more information about the hormonal modulation of such responses in the oral cavity is needed. Gingival fibroblasts (GF), major components of the oral tissues, are potentially sources for inflammatory mediators.

METHODS

Macroarrays specific for cytokines and related proteins were used to examine the regulation of gene expression in GF under serum-free, resting conditions, after immune challenge with interleukin-1beta (IL-1beta), and in the presence of IL-1beta plus a progestin, +/-17beta-estradiol. Additional studies used enzymelinked immunosorbent assays (ELISAs) to test for secreted chemokines after the same treatments.

RESULTS

Of the 392 genes on the macroarray, 66 were up- or downregulated at least 2-fold relative to the unstimulated control in an average of six different sub-lines. Chemokines represented the largest group (18%) of these regulated genes. Numerous genes whose expression was upregulated by IL-1beta were modulated downward by IL-1beta plus progestin, +/-17beta-estradiol. Measurements of the secretion of IL-8, a CXC chemokine, and MCP-1, a CC chemokine, confirmed the inhibitory effect of a progestin on these genes.

CONCLUSIONS

Gingival fibroblasts are active participants in the immune response in the oral cavity, and may potentially produce many chemokine signals after exposure to IL-1beta. GF can attract neutrophils, monocytes, eosinophils, and fibroblasts to the area of injury, and aid in the wound repair process. The concentration of female sex hormones, especially progestin, may significantly affect these signaling systems.

Molecular cloning and preliminary expression analysis of banded dogfish (Triakis scyllia) CC chemokine cDNAs by use of suppression subtractive hybridization

Suppression subtractive hybridization was carried out by using cDNAs of peripheral white blood cells (PWBCs) of banded dogfish (Triakis scyllia) after phorbol 12-myristate 13-acetate (PMA) stimulation. The Trsc-SCYA107, MIP3alpha1 and MIP3alpha2 clones contained an open reading frame encoding 97, 99 and 97 amino acids, respectively. Comparison of the deduced amino acids showed that the banded dogfish MIP3alpha1 and MIP3alpha2 sequences shared 42.3% and 40.0% identity with human SCYA20, respectively, while the Trsc-SCYA107 sequence shared 50.6, 44.2 and 42.0% identity with the catshark (Scyliorhinus canicula) Scca-SCYA107, rainbow trout (Oncorhynchus mykiss) CK4A and CK4B, respectively. The genomic sequences of banded dogfish Trsc-SCYA107, MIP3alpha1 and MIP3alpha2 contain four exons and three introns, and MIP3alpha1 and MIP3alpha2 shared the same intron/exon organization with that of human. The MIP3alpha1 and MIP3alpha2 genes of lipopolysaccharide (LPS)-unstimulated banded dogfish were expressed in gill, kidney and liver, while Trsc-SCYA107 mRNA was detected in various tissues except for brain. However, the constitutive expression of MIP3alpha2 gene was much lower than the Trsc-SCYA107 and MIP3alpha1 genes. RT-PCR analysis of the Trsc-SCYA107 expression in tissues of LPS-stimulated fish showed enhanced expression at 24 h poststimulation in the gill, heart, leydig, spleen and testes, while the expression of MIP3alpha1 and MIP3alpha2 was not influenced by LPS-stimulation in vivo. Furthermore, a relative increase in the expression of the Trsc-SCYA107 and MIP3alpha2 genes in PWBCs was observed at 1-12 h poststimulation with PMA and LPS, with maximal expression observed at 3 h, while MIP3alpha1 expression was observed at 3-12 h poststimulation only with PMA.