Colon cancer cells secreted CXCL11 via RBP-Jκ to facilitated tumour-associated macrophage-induced cancer metastasis.

Metastasis is the main cause of colon cancer-related deaths. RBP-Jκ is involved in colon cancer development, but its function in colon cancer metastasis is still unclear. Tumour-associated macrophages are the main cell components in tumour microenvironments. Here, we aimed to determine the function of RBP-Jκ in colon cancer metastasis and its underlying mechanisms for modulating interactions between colon cancer cell and tumour-associated macrophages. Through bioinformation analysis, we found that RBP-Jκ was overexpressed in colon cancer tissues and associated with advanced colon cancer phenotypes, macrophage infiltration and shorter survival overall as confirmed by our patients' data. And our patients' data show that RBP-Jκ expression and tumour-associated macrophages infiltration are associated with colon cancer metastasis and are independent prognostic factors for colon cancer patients. Tumour-associated macrophages induced colon cancer cell migration, invasion and epithelial-mesenchymal transition through secreting TGF-ß1. Colon cancer cells with high RBP-Jκ expression induced the expression of TGF-ß1 in tumour-associated macrophages by secreting CXCL11. Our research revealed that colon cancer cells secreted CXCL11 via overexpression of RBP-Jκ to enhance the expression of TGF-ß1 in tumour-associated macrophages to further promote metastasis of colon cancer cells.

An Oncogenic Alteration Creates a Microenvironment that Promotes Tumor Progression by Conferring a Metabolic Advantage to Regulatory T Cells.

Only a small percentage of patients afflicted with gastric cancer (GC) respond to immune checkpoint blockade (ICB). To study the mechanisms underlying this resistance, we examined the immune landscape of GC. A subset of these tumors was characterized by high frequencies of regulatory T (Treg) cells and low numbers of effector T cells. Genomic analyses revealed that these tumors bore mutations in RHOA that are known to drive tumor progression. RHOA mutations in cancer cells activated the PI3K-AKT-mTOR signaling pathway, increasing production of free fatty acids that are more effectively consumed by Treg cells than effector T cells. RHOA mutant tumors were resistant to PD-1 blockade but responded to combination of PD-1 blockade with inhibitors of the PI3K pathway or therapies targeting Treg cells. We propose that the metabolic advantage conferred by RHOA mutations enables Treg cell accumulation within GC tumors, generating an immunosuppressive TME that underlies resistance to ICB.

CXCL9, CXCL10, CXCL11, and their receptor (CXCR3) in neuroinflammation and neurodegeneration.

The aim of this review is to present data from the available literature concerning CXCL9, CXCL10 and CXCL11, as well as their receptor 3 (CXCR3) in selected diseases of the central nervous system (CNS), such as tickborne encephalitis (TBE), neuroborreliosis (NB), Alzheimer's disease (AD), and multiple sclerosis (MS). CXCL9, CXCL10, and CXCL11 lack glutamic acid-leucine-arginine (ELR), and are unique, because they are more closely related to each other than to any other chemokine. The aforementioned chemokines are especially involved in Th1-type response and in various diseases, as their expression correlates with the tissue infiltration of T cells. Their production is strongly induced by interferon gamma (IFN-υ), the most typical Th1 cytokine. They act by binding to the CXC3 receptor. Knowledge about the action mechanism of CXCR3 and its ligands may be useful in the treatment of CNS diseases. However, data in the literature concerning the evaluation of CXCL9, CXCL10, CXCL11, and their receptor with the use of the enzyme-linked immunosorbent assay (ELISA) method is limited.

MiR-206 inhibits proliferation and migration of prostate cancer cells by targeting CXCL11.

BACKGROUND: Our study was aimed at detecting the expression levels of miR-206 in prostate cancer (PCa) tissues and PCa cell lines, and exploring the potential functions of miR-206 by targeting chemokine ligand 11 (CXCL11). METHODS: RT-qPCR was applied to detect the expressions of miR-206 and CXCL11 in PCa tissues and in PCa cell lines. Expression of the CXCL11 protein was detected using Western blot. After manipulating the expression of miR-206 and CXCL11 in PC-3 and DU-145 cells, the changes of cell proliferation and cell cycle were observed through cell counting kit-8 (CCK-8) and flow cytometry. Wound healing and transwell assay were conducted for cell migration and invasion examination in vitro. The luciferase reporter assay was applied to validate the association between miR-206 and CXCL11. RESULTS: MiR-206 was significantly under-expressed in PCa tissues and in PCa cell lines. Up-regulation of miR-206 could inhibit proliferation, migration, invasion and induced G1/G0 arrest of PCa cells, and vice versa. MiR-206 bound to the 3'-UTR of CXCL11 and significantly repressed the luciferase activity. Overexpression of miR-206 decreased the expression level of CXCL11 significantly. CXCL11 mRNA and protein levels were significantly decreased in PCa cells. Downregulation of CXCL11 presented tumor-suppressing effects on PCa cells as miR-206 mimics did. And co-transfection miR-206 attenuated the tumor-promoting effects induced by CXCL11 overexpression. CONCLUSION: Our current finding demonstrated that miR-206 negatively regulated PCa cell proliferation and migration, and arrested cell cycle by targeting CXCL11 as a tumor suppressor in prostate cancer.

A 2-Protein Signature Predicting Clinical Outcome in High-Grade Serous Ovarian Cancer.

OBJECTIVE: High-grade serous ovarian cancer (HGSOC) accounts for approximately 70% deaths in ovarian cancer. The overall survival (OS) of HGSOC is poor and still remains a clinical challenge. High-grade serous ovarian cancer can be divided into 4 molecular subtypes. The prognosis of different molecular subtypes is still unclear. We aimed to investigate the prognostic values of immunohistochemistry-based different molecular subtypes in patients with HGSOC. METHODS: We analyzed the protein expression of representative biomarkers (CXCL11, HMGA2, and MUC16) of 3 different molecular subtypes in 110 formalin-fixed, paraffin-embedded HGSOC by tissue microarrays. RESULTS: High CXCL11 expression predicted worse OS, not disease-free survival (DFS; P = 0.028 for OS, P = 0.191 for DFS). High HMGA2 expression predicted worse OS and DFS (P = 0.037 for OS, P = 0.021 for DFS). MUC16 expression was not associated with OS or DFS (P = 0.919 for OS, P = 0.517 for DFS). Multivariate regression analysis showed that CXCL11 combined with HMGA2 signature was an independent predictor for OS and DFS in patients with HGSOC. CONCLUSIONS: CXCL11 combined with HMGA2 signature was a clinically applicable prognostic model that could precisely predict an HGSOC patient's OS and tumor recurrence. This model could serve as an important tool for risk assessment of HGSOC prognosis.

Sulforaphane inhibits the interferon-γ-induced expression of MIG, IP-10 and I-TAC in INS­1 pancreatic ß-cells through the downregulation of IRF-1, STAT-1 and PKB.

Sulforaphane (SFN) is a dietary isothiocyanate abundantly available in cruciferous vegetables and has been shown to possess anti-inflammatory and immunomodulatory activities. Chemokines are important mediators of inflammation and immune responses due to their ability to recruit and activate macrophages and leukocytes. To date, little is known about the SFN-mediated regulation of chemokine expression in pancreatic ß-cells. In this study, we investigated the inhibitory effects and mechanisms of SFN on the interferon-γ (IFN-γ)-induced expression of a subset of chemokines, including monokine induced by IFN-γ (MIG), IFN-inducible protein of 10 kDa (IP-10) and IFN-inducible T­cell alpha chemoattractant (I-TAC), in INS­1 cells, a rat pancreatic ß-cell line. Notably, IFN-γ treatment led to an increase in the mRNA expression levels of MIG, IP-10 and I-TAC in the INS­1 cells. However, SFN strongly blocked the mRNA expressions of MIG, IP-10 and I-TAC induced by IFN-γ in INS­1 cells. On the mechanistic level, SFN significanlty decreased not only the mRNA expression levels of interferon regulatory factor-1 (IRF-1), but also the phosphorylation levels of signal transducer and activator of transcription-1 (STAT-1) and protein kinase B (PKB) which were induced by IFN-γ in the INS­1 cells. Pharmacological inhibition experiments further revealed that treatment with JAK inhibitor I weakly inhibited the IFN-γ-induced expression of IP-10, whereas it strongly suppressed the IFN-γ-induced expression of MIG and I-TAC in the INS­1 cells. Moreover, treatment with LY294002, a PI3K/PKB inhibitor, was able to slightly repress IFN­Î³­induced expressions of MIG and I-TAC, but not IP-10, in INS­1 cells. Importantly, the IFN-γ-induced increase in the expression levels of MIG, IP-10 and I-TAC in the INS-1 cells was strongly inhibited by SFN, but not by other natural substances, such as curcumin, sanguinarine, resveratrol, triptolide and epigallocatechin gallate (EGCG), suggesting the specificity of SFN in downregulating the levels of these chemokines. To the best of our knowledge, these results collectively demonstrate for the first time that SFN strongly inhibits the IFN-γ-induced expression of MIG, IP-10 and I-TAC in INS­1 cells and this inhibition is, at least in part, mediated through the reduced expression and phosphorylation levels of IRF-1, STAT-1 and PKB.

STAT2 is involved in the pathogenesis of psoriasis by promoting CXCL11 and CCL5 production by keratinocytes.

The JAK/STAT signaling pathway is suggested to play an important role in the pathogenesis of psoriasis, and recently JAK/STAT inhibitors have shown promising results in psoriasis treatment. The present study aimed to characterize the role of STAT2 in psoriasis. We demonstrated an increased expression of STAT2 and an increased level of phosphorylated/activated STAT2 in lesional compared with nonlesional psoriatic skin. Gene silencing of STAT2 by siRNA in human keratinocytes revealed that upon IFNα stimulation CXCL11 and CCL5 were the only two cytokines, among 102 analyzed, found to be regulated through a STAT2-dependent mechanism. Moreover, the regulation of CXCL11 and CCL5 depended on IRF9, but not on STAT1 and STAT6. The CXCL11 and CCL5 expression was increased in lesional compared with nonlesional psoriatic skin, and analysis demonstrated positive correlation between the expression of CXCL11 and IFNγ and between the expression of CCL5 and IFNγ in lesional psoriatic skin. In contrast, no correlation between the expression of CXCL11 and IL-17A and the expression of CCL5 and IL-17A in lesional psoriatic skin was found. Our data suggest that STAT2 plays a role in the psoriasis pathogenesis by regulating the expression of CXCL11 and CCL5, and thereby attracting IFNγ-producing immune cells to the skin.

CXCL11 mediates TWIST1-induced angiogenesis in epithelial ovarian cancer.

To investigate the role of TWIST1 in tumor angiogenesis in epithelial ovarian cancer and to identify key molecules involved in angiogenesis. TWIST1 small interfering RNA was transfected into A2780 cells, while a complementary DNA vector was transfected into non-malignant human ovarian surface epithelial cells to generate a TWIST1-overexpressing cell line. To evaluate how this affects angiogenesis, human umbilical vein endothelial cell tube formation assays were performed using the control and transfected cell lines. An antibody-based cytokine array was used to identify the molecules involved in TWIST1-mediated angiogenesis. After knockdown of TWIST1 via transfection of TWIST1 small interfering RNA into A2780 cells, the number of tubes formed by human umbilical vein endothelial cells significantly decreased in a tube formation assay. In a cytokine array, TWIST1 downregulation did not significantly decrease the secretion of the common pro-angiogenic factor, vascular endothelial growth factor, but instead inhibited the expression of the CXC chemokine ligand 11, which was confirmed by both an enzyme-linked immunosorbent assay and western blotting. In contrast, TWIST1 overexpression resulted in increased secretion of CXC chemokine ligand 11. Conversely, CXC chemokine ligand 11 downregulation did not inhibit the expression of TWIST1. Furthermore, the ability of TWIST1-expressing A2780 cells to induce angiogenesis was found to be inhibited after CXC chemokine ligand 11 knockdown in a tube formation assay. TWIST1 plays an important role in angiogenesis in epithelial ovarian cancer and is mediated by a novel pro-angiogenic factor, CXC chemokine ligand 11. Downregulation of CXC chemokine ligand 11 can inhibit tumor angiogenesis, suggesting that anti-CXC chemokine ligand 11 therapy may offer an alternative treatment strategy for TWIST1-positive ovarian cancer.

RIPK4 activates an IRF6-mediated proinflammatory cytokine response in keratinocytes.

Keratinocytes of the oral mucosa and epidermis play key roles in host defense. In addition to functioning as a physical barrier, they also produce cytokines to elicit inflammation in response to infection or injury. We recently established that receptor-interacting protein kinase 4 (RIPK4) and interferon regulatory factor 6 (IRF6) function as a cell-intrinsic signaling axis to regulate keratinocyte differentiation. In this study, we have demonstrated a functional relationship between RIPK4 and IRF6 in the control of proinflammatory cytokine expression in keratinocytes. The overexpression of RIPK4 by oral keratinocytes induced the strong expression of CCL5 and CXCL11. In contrast, the expression of other cytokines (e.g. IL8 and TNF) was largely unaffected, thus demonstrating specificity in the induction of proinflammatory cytokine expression by RIPK4. CCL5 and CXCL11 expression were also induced in response to the activation of the PKC pathway, and gene silencing experiments indicated that their inducible expression was dependent on RIPK4 and IRF6. Moreover, gene reporter assays suggested that RIPK4 induces CCL5 and CXCL11 expression by stimulating the transactivation of their promoters by IRF6. Accordingly, our findings suggest that the RIPK4-IRF6 signaling axis plays a multifaceted role in barrier epithelial homeostasis through its regulation of both keratinocyte inflammation and differentiation.

Loss of RUNX3 expression promotes cancer-associated bone destruction by regulating CCL5, CCL19 and CXCL11 in non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) frequently metastasizes to bone, which is associated with significant morbidity and a dismal prognosis. RUNX3 functions as a tumour suppressor in lung cancer and loss of expression occurs more frequently in invasive lung adenocarcinoma than in pre-invasive lesions. Here, we show that RUNX3 and RUNX3-regulated chemokines are linked to NSCLC-mediated bone resorption. Notably, the receptor activator of nuclear factor-κB ligand (RANKL)/osteoprotegerin (OPG) ratio, an index of osteoclastogenic stimulation, was significantly increased in human osteoblastic cells treated with conditioned media derived from RUNX3-knockdown NSCLC cells. We aimed to identify RUNX3-regulated factors that modify the osteoblastic RANKL/OPG ratio and found that RUNX3 knockdown led to CCL5 up-regulation and down-regulation of CCL19 and CXCL11 in NSCLC cells. Tumour size was noticeably increased and more severe osteolytic lesions were induced in the calvaria and tibiae of mice that received RUNX3-knockdown cells. In response to RUNX3 knockdown, serum and tissue levels of CCL5 increased, whereas CCL19 and CXCL11 decreased. Furthermore, CCL5 increased the proliferation, migration, and invasion of lung cancer cells in a dose-dependent manner; however, CCL19 and CXCL11 did not show any significant effects. The RANKL/OPG ratio in osteoblastic cells was increased by CCL5 but reduced by CCL19 and CXCL11. CCL5 promoted osteoclast differentiation, but CCL19 and CXCL11 reduced osteoclastogenesis in RANKL-treated bone marrow macrophages. These findings suggest that RUNX3 and related chemokines are useful markers for the prediction and/or treatment of NSCLC-induced bone destruction.

Androgen receptor and chemokine receptors 4 and 7 form a signaling axis to regulate CXCL12-dependent cellular motility.

BACKGROUND: Identifying cellular signaling pathways that become corrupted in the presence of androgens that increase the metastatic potential of organ-confined tumor cells is critical to devising strategies capable of attenuating the metastatic progression of hormone-naïve, organ-confined tumors. In localized prostate cancers, gene fusions that place ETS-family transcription factors under the control of androgens drive gene expression programs that increase the invasiveness of organ-confined tumor cells. C-X-C chemokine receptor type 4 (CXCR4) is a downstream target of ERG, whose upregulation in prostate-tumor cells contributes to their migration from the prostate gland. Recent evidence suggests that CXCR4-mediated proliferation and metastasis of tumor cells is regulated by CXCR7 through its scavenging of chemokine CXCL12. However, the role of androgens in regulating CXCR4-mediated motility with respect to CXCR7 function in prostate-cancer cells remains unclear. METHODS: Immunocytochemistry, western blot, and affinity-purification analyses were used to study how androgens influenced the expression, subcellular localization, and function of CXCR7, CXCR4, and androgen receptor (AR) in LNCaP prostate-tumor cells. Moreover, luciferase assays and quantitative polymerase chain reaction (qPCR) were used to study how chemokines CXCL11 and CXCL12 regulate androgen-regulated genes (ARGs) in LNCaP prostate-tumor cells. Lastly, cell motility assays were carried out to determine how androgens influenced CXCR4-dependent motility through CXCL12. RESULTS: Here we show that, in the LNCaP prostate-tumor cell line, androgens coordinate the expression of CXCR4 and CXCR7, thereby promoting CXCL12/CXCR4-mediated cell motility. RNA interference experiments revealed functional interactions between AR and CXCR7 in these cells. Co-localization and affinity-purification experiments support a physical interaction between AR and CXCR7 in LNCaP cells. Unexpectedly, CXCR7 resided in the nuclear compartment and modulated AR-mediated transcription. Moreover, androgen-mediated cell motility correlated positively with the co-localization of CXCR4 and CXCR7 receptors, suggesting that cell migration may be linked to functional CXCR4/CXCR7 heterodimers. Lastly, CXCL12-mediated cell motility was CXCR7-dependent, with CXCR7 expression required for optimal expression of CXCR4 protein. CONCLUSIONS: Overall, our results suggest that inhibition of CXCR7 function might decrease the metastatic potential of organ-confined prostate cancers.

Listr1 locus regulates innate immunity against Listeria monocytogenes infection in the mouse liver possibly through Cxcl11 polymorphism.

Inbred stains of mice display differential susceptibility to infection with the common foodborne pathogen Listeria monocytogenes (Lm). Previously, Listr1 and Listr2, two genetic loci that control differential sensitivity to Lm infection between BALB/cByJ and C57BL/6ByJ mice, were identified. To analyze the role of Listr1 in innate immune responses, we employed congenic mice (C.B6By-Listr1/Rag2 (-/-) ) bearing the C57BL/6ByJ-derived Listr1 locus on a BALB/c-Rag2 (-/-) background. Consistent with the results of a previous genetic analysis, the congenic mice showed increased susceptibility to Lm infection. The bacterial burden in the liver between the congenic and control lines was significantly different (P < 0.05) from 24 h postinfection with Lm. Analysis of genes within the Listr1 locus identified a frameshift mutation in the Cxcl11 gene of the C57BL/6 strain that prevents production of the mature chemokine CXCL11. No differences in inflammatory cell infiltration or cells expressing CXCR3 and CXCR7 which are the receptors of CXCL11 occurred because of CXCL11 deficiency in the congenic mice spleens. However, these mice lacked a distinct population of CD14(+) positive resident mononuclear cells that express intermediate levels of CXCR3 and CXCR7 in the liver. There were fewer microabscesses in the liver of CXCL11-deficient mice during the early stage of infection, which is consistent with their decreased ability to resist Lm. Our results, when taken together, show that the Listr1 locus plays an important role in early control of Lm infection in the mouse liver and that Cxcl11 is a candidate gene for disease severity within this locus.

Cleavage of the T cell protein tyrosine phosphatase by the hepatitis C virus nonstructural 3/4A protease induces a Th1 to Th2 shift reversible by ribavirin therapy.

Ribavirin has proven to be a key component of hepatitis C therapies both involving IFNs and new direct-acting antivirals. The hepatitis C virus-mediated interference with intrahepatic immunity by cleavage of mitochondrial antiviral signaling protein (MAVS) and T cell protein tyrosine phosphatase (TCPTP) suggests an avenue for compounds that may counteract these effects. We therefore studied the effects of ribavirin, with or without inhibition of the nonstructural (NS)3/4A protease, on intrahepatic immunity. The intrahepatic immunity of wild-type and NS3/4A-transgenic mice was determined by Western blot, ELISA, flow cytometry, and survival analysis. Various MAVS or TCPTP constructs were injected hydrodynamically to study their relevance. Ribavirin pretreatment was performed in mice expressing a functional or inhibited NS3/4A protease to analyze its effect on NS3/4A-mediated changes. Intrahepatic NS3/4A expression made mice resistant to TNF-α-induced liver damage and caused an alteration of the intrahepatic cytokine (IFN-γ and IL-10) and chemokine (CCL3, CCL17, CCL22, CXCL9, and CXCL11) profiles toward an anti-inflammatory state. Consistent with this, the number of intrahepatic Th1 cells and IFN-γ(+) T cells in NS3/4A-transgenic mice decreased, whereas the amount of Th2 cells increased. These effects could be reversed by injection of uncleavable TCPTP but not uncleavable MAVS and were absent in a mouse expressing a nonfunctional NS3/4A protease. Importantly, the NS3/4A-mediated effects were reversed by ribavirin treatment. Thus, cleavage of TCPTP by NS3/4A induces a shift of the intrahepatic immune response toward a nonantiviral Th2-dominated immunity. These effects are reversed by ribavirin, supporting that ribavirin complements the effects of direct-acting antivirals as an immunomodulatory compound.

Alternaria inhibits double-stranded RNA-induced cytokine production through Toll-like receptor 3.

BACKGROUND: Fungi may be involved in asthma and chronic rhinosinusitis (CRS). Peripheral blood mononuclear cells from CRS patients produce interleukin (IL)-5, IL-13 and interferon (IFN)-γ in the presence of Alternaria. In addition, Alternaria produces potent Th2-like adjuvant effects in the airway. Therefore, we hypothesized that Alternaria may inhibit Th1-type defense mechanisms against virus infection. METHODS: Dendritic cells (DCs) were generated from mouse bone marrow. The functional responses were assessed by expression of cell surface molecules by FACS (MHC class II, CD40, CD80, CD86 and OX40L). Production of IL-6, chemokine CXCL10 (IP-10), chemokine CXCL11 (I-TAC) and IFN-ß was measured by ELISA. Toll-like receptor 3 (TLR3) mRNA and protein expression was detected by quantitative real-time PCR and Western blot. RESULTS: Alternaria and polyinosinic-polycytidylic acid (poly I:C) enhanced cell surface expression of MHC class II, CD40, CD80, CD86 and OX40L, and IL-6 production in a concentration-dependent manner. However, Alternaria significantly inhibited production of IP-10, I-TAC and IFN-ß, induced by viral double-stranded RNA (dsRNA) mimic poly I:C. TLR3 mRNA expression and protein production by poly I:C were significantly inhibited by Alternaria. These reactions are likely caused by heat-stable factor(s) in Alternaria extract with >100 kDa molecular mass. CONCLUSION: These findings suggest that the fungus Alternaria may inhibit production of IFN-ß and other cytokines by DCs by suppressing TLR3 expression. These results indicate that Alternaria may inhibit host innate immunity against virus infection.

Airway smooth muscle CXCR3 ligand production: regulation by JAK-STAT1 and intracellular Ca²âº.

In asthma, airway smooth muscle (ASM) chemokine (C-X-C motif) receptor 3 (CXCR3) ligand production may attract mast cells or T lymphocytes to the ASM, where they can modulate ASM functions. In ASM cells (ASMCs) from people with or without asthma, we aimed to investigate JAK-STAT1, JNK, and Ca²âº involvement in chemokine (C-X-C motif) ligand (CXCL)10 and CXCL11 production stimulated by interferon-γ, IL-1ß, and TNF-α combined (cytomix). Confluent, growth-arrested ASMC were treated with inhibitors for pan-JAK (pyridone-6), JAK2 (AG-490), JNK (SP-600125), or the sarco(endo)plasmic reticulum Ca²âºATPase (SERCA) pump (thapsigargin), Ca²âº chelator (BAPTA-AM), or vehicle before and during cytomix stimulation for up to 24 h. Signaling protein activation as well as CXCL10/CXCL11 mRNA and protein production were examined using immunoblot analysis, real-time PCR, and ELISA, respectively. Cytomix-induced STAT1 activation was lower and CXCR3 ligand mRNA production was more sensitive to pyridone-6 and AG-490 in asthmatic than nonasthmatic ASMCs, but CXCL10/CXCL11 release was inhibited by the same proportion. Neither agent caused additional inhibition of release when used in combination with the JNK inhibitor SP-600125. Conversely, p65 NF-κB activation was higher in asthmatic than nonasthmatic ASMCs. BAPTA-AM abolished early CXCL10/CXCL11 mRNA production, whereas thapsigargin reduced it in asthmatic cells and inhibited CXCL10/CXCL11 release by both ASMC types. Despite these inhibitory effects, neither Ca²âº agent affected early activation of STAT1, JNK, or p65 NF-κB. In conclusion, intracellular Ca²âº regulated CXCL10/CXCL11 production but not early activation of the signaling molecules involved. In asthma, reduced ASM STAT1-JNK activation, increased NF-κB activation, and altered Ca²âº handling may contribute to rapid CXCR3 ligand production and enhanced inflammatory cell recruitment.

IL-27 inhibits lymphatic endothelial cell proliferation by STAT1-regulated gene expression.

OBJECTIVE: IL-27 belongs to the IL-12 family of cytokines and is recognized for its role in Th cell differentiation and as an inhibitor of tumor angiogenesis. The purpose of this study was to investigate the effect of IL-27 on proliferation of lymphatic endothelial cells to gain insight into the interplay between the immune system and development of the lymphatic system. METHODS: IL-27-stimulated signal transduction in human dermal lymphatic endothelial cells was measured by western blotting and synthesis of CXCL10 and CXCL11 by use of RT-PCR and ELISA. Proliferation was measured using MTT and BrdU kits and the role of STAT1 and chemokines was determined by use of siRNA and recombinant proteins. RESULTS: Stimulation of lymphatic endothelial cell cultures with IL-27 induced JAK dependent phosphorylation of STAT1 and STAT3 and inhibited lymphatic endothelial cell proliferation and migration. Expression of CXCL10 and CXCL11, both STAT1 target genes, was profoundly up-regulated upon IL-27 stimulation, and recombinant CXCL10 and CXCL11 inhibited FGF-2-induced proliferation in vitro. siRNA targeting of STAT1 almost completely abrogated CXCL10 and CXCL11 expression as well as the proliferative effect of IL-27. CONCLUSIONS: IL-27 function as an anti-lymphangiogenic regulator in vitro by up-regulating chemokines and interfering with the mitogenic effect of growth factors through STAT1 activation.

[Expressions of CXCL9, CXCL10 and CXCL11 in renal tubular epithelial cells induced by IFN-γ].

OBJECTIVE: To investigate the effect of interferon-γ (IFN-γ) on the releases of CXCL9, CXCL10 and CXCL11 in renal proximal tubular epithelial cells (HK-2) and explore their functions. METHODS: After stimulated by IFN-γ for different time, the HK-2 cells were analyzed by real-time PCR to detect the expressions of CXCL9, CXCL10 and CXCL11 mRNA, and were tested by ELISA to quantify the releases of CXCL9, CXCL10 and CXCL11 in supernatants. After activation of lymphocytes, cells were examined by flow cytometry to determine the CXCR3 expression, while chemotaxis assay was applied to evaluate the chemotactic effect of the supernatants of IFN-stimulated HK-2 cells on lymphocytes. RESULTS: Compared with the control group, the expressions of CXCL9, CXCL10 and CXCL11 mRNA in the IFN-stimulated group were significantly increased 12 h after stimulation, and peaked at 48, 24 and 24 h, respectively. The levels of CXCL9, CXCL10 and CXCL11 proteins began to rise at 12 h and reached the peak at 72, 48 and 72 h, respectively. Compared with the control group, the expression of CXCR3 was markedly increased in the activated lymphocytes. The activated lymphocytes were recruited by the culture supernatants of IFN-stimulated HK-2 cells and the pretreatment of CXCR3 antibody inhibited this chemotactic effect. CONCLUSION: IFN-γ can significantly up-regulate the expressions of chemokines such as CXCL9, CXCL10 and CXCL11 at both mRNA and protein levels in HK-2 cells.

Peroxisome proliferator-activated receptor-α agonists modulate CXCL9 and CXCL11 chemokines in Graves' ophthalmopathy fibroblasts and preadipocytes.

Peroxisome proliferator-activated receptors (PPAR)α have been shown to exert immunomodulatory effects in autoimmune disorders; no study evaluated the effect of PPARα activation in Graves' ophthalmopathy (GO). We show the presence of PPARα, δ and γ in GO fibroblasts and preadipocytes. PPARα activators have a potent inhibitory action on the secretion of CXCL9 and CXCL11 chemokines (induced by IFNγ and TNFα) in fibroblasts and preadipocytes. The potency of the used PPARα agonists was maximum on the secretion of CXCL11 (67% inhibition by fenofibrate) in fibroblasts. The relative potency of the compounds in GO fibroblasts was different with each chemokine. PPARα agonists were stronger inhibitors of CXCL9 and CXCL11 (in GO fibroblasts and preadipocytes) than PPARγ activators. This study first shows that PPARα activators inhibit CXCL9 and CXCL11 chemokines in normal and GO fibroblasts and preadipocytes, suggesting that PPARα may be involved in the modulation of the immune response in GO.

Microarray analysis of tonsils of IgA nephropathy patients.

IgA nephropathy (IgAN) is the most common primary glomerulonephritis. Its close relation with the tonsils is well known because tonsillitis sometimes causes aggravation of urinary findings or macrohematuria. However, the genes specific to the tonsils of IgAN patients are not clarified. To clarify the specific gene expression in the tonsils of IgAN patients, we performed tonsillectomy and corticosteroid IV therapy as a treatment of IgAN, analyzed the gene expression in the tonsils by microarray and compared it with that in tonsils from chronic tonsillitis patients. The upregulated genes seem to be categorized into two groups: muscle-related genes and immunerelated genes. The downregulated genes include the polymeric Ig receptor (pIgR) which was reportedly involved in single nucleotide polymorphism (SNP) of Japanese IgAN patients.

High serum levels of CXCL11 in mixed cryoglobulinemia are associated with increased circulating levels of interferon-γ.

OBJECTIVE: No study has evaluated circulating chemokine C-X-C motif ligand (CXCL)11 in patients with "mixed cryoglobulinemia and chronic hepatitis C infection" (MC+HCV). We measured CXCL11, and correlated this measurement to the clinical phenotype. METHODS: Serum CXCL11, interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α) were assayed in 97 MC+HCV patients and in 97 sex- and age-matched controls. RESULTS: MC+HCV patients showed significantly higher mean CXCL11 serum levels than controls (254 ± 295, 68 ± 16 pg/ml, respectively; p = 0.0002; ANOVA). CXCL11 was significantly increased in 36 cryoglobulinemic patients with compared to those without active vasculitis (303 ± 208 vs 179 ± 62 pg/ml, respectively; p < 0.001; ANOVA). IFN-γ levels were significantly higher in MC+HCV than in controls [6.1 (range 0.8-114.5), 1.4 (range 0.7-2.4) pg/ml, respectively; p < 0.05; Mann-Whitney U test]. Serum TNF-α mean levels were significantly higher in MC+HCV than in controls [13.4 (range 1.8-369), 1.1 (range 0.7-3.2) pg/ml, respectively; p < 0.0001; Mann-Whitney U test]. A multiple regression analysis considering CXCL11 as a dependent variable, and age, alanine aminotransferase, IFN-γ, and TNF-α as independent variables, showed in MC+HCV patients a significant association only with IFN-γ (p < 0.0001). CONCLUSION: Our study demonstrates markedly high serum levels of CXCL11 in patients with MC+HCV compared to healthy controls overall in the presence of active vasculitis. A strong relationship between circulating IFN-γ and CXCL11 was shown, strongly supporting the role of a T helper 1 immune response in the pathogenesis of MC+HCV.