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Chemokine Production (chemokine + production)
Selected AbstractsRole of TNF, in Early Chemokine Production and Leukocyte Infiltration into Heart AllograftsAMERICAN JOURNAL OF TRANSPLANTATION, Issue 1 2010D. Ishii The acute phase cytokines IL-1,, IL-6 and TNF, are produced early during inflammatory processes, including ischemia-reperfusion. The appearance and role of these cytokines in the early inflammation following reperfusion of grafts remain poorly defined. This study investigated the role of TNF, in the induction of early leukocyte infiltration into vascularized heart allografts. TNF, and IL-6 mRNA levels reached an initial peak 3 h posttransplant and a second peak at 9,12 h with equivalent levels in iso- and allografts. A single dose of anti-TNF, mAb given at reperfusion decreased neutrophil and macrophage chemoattractant levels and early neutrophil, macrophage and memory CD8 T-cell infiltration into allografts. Anti-TNF, mAb also extended graft survival from 8.6 ± 0.6 days to 14.1 ± 0.8 days. When assessed on day 7 posttransplant, the number of donor-reactive CD8 T cells producing IFN-, in the spleen was reduced almost 70% in recipients treated with anti-TNF, mAb. Whereas anti-CD154 mAb prolonged survival to day 21, administration of anti-TNF, and anti-CD154 mAb delayed rejection to day 32 and resulted in long-term (>80 days) survival of 40% of the heart allografts. These data implicate TNF, as an important mediator of early inflammatory events in allografts that undermine graft survival. [source] Staphylococcus aureus enterotoxin B augments granulocyte migration and survival via airway epithelial cell activationALLERGY, Issue 8 2010W. Huvenne To cite this article: Huvenne W, Callebaut I, Reekmans K, Hens G, Bobic S, Jorissen M, Bullens DMA, Ceuppens JL, Bachert C, Hellings PW. Staphylococcus aureus enterotoxin B augments granulocyte migration and survival via airway epithelial cell activation. Allergy 2010; 65: 1013,1020. Abstract Background:,Staphylococcus aureus enterotoxin B (SEB) has recently been postulated to be involved in the pathology of granulocyte-dominated disease. Studying the immunologic interaction between SEB and airway epithelial cells in immortalized cell lines or long-term epithelial cell cultures has obvious disadvantages. Methods:, We used a novel technique of freshly isolated and purified human nasal epithelial cells (HNEC) from healthy, nonallergic individuals, which were incubated for 24 h without/with SEB at different concentrations. Chemokine production was evaluated in the supernatant using Cytometric Bead Array. The chemotactic activity of the supernatant was studied in vitro using a Boyden chamber. Survival was evaluated with flow cytometry, using propidium iodide to identify dead cells. Results:,Staphylococcus aureus enterotoxin B showed a dose-dependent induction of interferon-inducible protein-10, monokine induced by interferon-,, regulated upon activation normal T cell expressed and secreted, monocyte chemoattractant protein 1 (MCP-1) and granulocyte colony stimulating factor production by epithelial cells in vitro. The supernatant of epithelial cells had chemotactic activity for granulocytes in vitro, which was enhanced in the supernatant of SEB-stimulated epithelial cells. Reduced number of propidium iodide positive granulocytes was found in the conditions where supernatant of SEB-stimulated epithelial cells was applied. Conclusion:,Staphylococcus aureus enterotoxin B exerts a direct pro-inflammatory effect on HNEC, with induction of chemokine and growth factor release, resulting in the migration and prolonged survival of granulocytes in vitro. [source] Impairment of dendritic cell function by excretory-secretory products: A potential mechanism for nematode-induced immunosuppressionEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 7 2007Mariela Segura Abstract To determine whether helminth-derived products modulate dendritic cell (DC) function, we investigated the effects of excretory-secretory products (ES) and adult worm homogenate (AWH) derived from the gastrointestinal nematode Heligmosomoides polygyrus (Hp) on murine bone marrow-derived DC (BMDC). Compared to the TLR9 ligand CpG, Hp-derived products alone failed to induce DC activation. ES, but not AWH, inhibited BMDC cytokine and chemokine production and co-stimulatory molecule expression (CD40, CD86 and MHC class,II) induced by TLR ligation. TLR ligand-independent, PMA-induced DC activation was unaffected by ES. Recipients of ES-treated BMDC pulsed with OVA had suppressed Ab responses in vivo, irrespective of the Th1 or Th2 isotype affiliation, compared to recipients of control OVA-pulsed BMDC. Importantly, suppression occurred even in the presence of the potent type,1 adjuvant CpG. In contrast to untreated OVA-pulsed BMDC, ES-treated BMDC pulsed with OVA had reduced co-stimulatory molecule and cytokine expression. CD4+CD25+Foxp3, T cells, which secreted high IL-10 levels, were generated in co-cultures of OT-II OVA-specific TCR-transgenic CD4+ T cells and ES-treated BMDC. These IL-10-secreting T cells suppressed effector CD4+ T cell proliferation and IFN-, production, the latter effect mediated by an IL-10-dependent mechanism. Together, these results demonstrate that nematode ES impaired DC function and suppressed both Th1 and Th2 adaptive immune responses possibly by inducing regulatory T cells. [source] Human lactoferrin activates NF-,B through the Toll-like receptor 4 pathway while it interferes with the lipopolysaccharide-stimulated TLR4 signalingFEBS JOURNAL, Issue 9 2010Ken Ando Lactoferrin (LF) has been implicated in innate immunity. Here we reveal the signal transduction pathway responsible for human LF (hLF)-triggered nuclear factor-,B (NF-,B) activation. Endotoxin-depleted hLF induces NF-,B activation at physiologically relevant concentrations in the human monocytic leukemia cell line, THP-1, and in mouse embryonic fibroblasts (MEFs). In MEFs, in which both tumor necrosis factor receptor-associated factor 2 (TRAF2) and TRAF5 are deficient, hLF causes NF-,B activation at a level comparable to that seen in wild-type MEFs, whereas TRAF6-deficient MEFs show significantly impaired NF-,B activation in response to hLF. TRAF6 is known to be indispensable in leading to NF-,B activation in myeloid differentiating factor 88 (MyD88)-dependent signaling pathways, while the role of TRAF6 in the MyD88-independent signaling pathway has not been clarified extensively. When we examined the hLF-dependent NF-,B activation in MyD88-deficient MEFs, delayed, but remarkable, NF-,B activation occurred as a result of the treatment of cells with hLF, indicating that both MyD88-dependent and MyD88-independent pathways are involved. Indeed, hLF fails to activate NF-,B in MEFs lacking Toll-like receptor 4 (TLR4), a unique TLR group member that triggers both MyD88-depependent and MyD88-independent signalings. Importantly, the carbohydrate chains from hLF are shown to be responsible for TLR4 activation. Furthermore, we show that lipopolysaccharide-induced cytokine and chemokine production is attenuated by intact hLF but not by the carbohydrate chains from hLF. Thus, we present a novel model concerning the biological function of hLF: hLF induces moderate activation of TLR4-mediated innate immunity through its carbohydrate chains; however, hLF suppresses endotoxemia by interfering with lipopolysaccharide-dependent TLR4 activation, probably through its polypeptide moiety. [source] Neutrophil depletion protects against murine acetaminophen hepatotoxicity,,HEPATOLOGY, Issue 6 2006Zhang-Xu Liu We previously reported that liver natural killer (NK) and NKT cells play a critical role in mouse model of acetaminophen (APAP)-induced liver injury by producing interferon gamma (IFN-,) and modulating chemokine production and subsequent recruitment of neutrophils into the liver. In this report, we examined the role of neutrophils in the progression of APAP hepatotoxicity. C57BL/6 mice were given an intraperitoneal toxic dose of APAP (500 mg/kg), which caused severe acute liver injury characterized by significant elevation of serum ALT, centrilobular hepatic necrosis, and increased hepatic inflammatory cell accumulation. Flow cytometric analysis of isolated hepatic leukocytes demonstrated that the major fraction of increased hepatic leukocytes at 6 and 24 hours after APAP was neutrophils (Mac-1+Gr-1+). Depletion of neutrophils by in vivo treatment with anti-Gr-1 antibody (RB6-8C5) significantly protected mice against APAP-induced liver injury, as evidenced by markedly reduced serum ALT levels, centrilobular hepatic necrosis, and improved mouse survival. The protection was associated with decreased FasL-expressing cells, cytotoxicity against hepatocytes, and respiratory burst in hepatic leukocytes. In intracellular adhesion molecule (ICAM)-1,deficient mice, APAP caused markedly reduced liver injury when compared with wild-type mice. The marked protection in ICAM-1,deficient mice was associated with decreased accumulation of neutrophils in the liver. Hepatic GSH depletion and APAP-adducts showed no differences among the antibody-treated, ICAM-1,deficient, and normal mice. In conclusion, accumulated neutrophils in the liver contribute to the progression and severity of APAP-induced liver injury. (HEPATOLOGY 2006;43:1220,1230.) [source] Inflammation and drug hepatotoxicity: Aggravation of injury or clean-up mission?,HEPATOLOGY, Issue 5 2005Hartmut Jaeschke BACKGROUND & AIMS Inflammatory mediators released by nonparenchymal inflammatory cells in the liver have been implicated in the progression of acetaminophen (APAP) hepatotoxicity. Among hepatic nonparenchymal inflammatory cells, we examined the role of the abundant natural killer (NK) cells and NK cells with T-cell receptors (NKT cells) in APAP-induced liver injury. METHODS C57BL/6 mice were administered a toxic dose of APAP intraperitoneally to cause liver injury with or without depletion of NK and NKT cells by anti-NK1.1 monoclonal antibody (MAb). Serum alanine transaminase (ALT) levels, liver histology, hepatic leukocyte accumulation, and cytokine/chemokine expression were assessed. RESULTS Compared with APAP-treated control mice, depletion of both NK and NKT cells by anti-NK1.1 significantly protected mice from APAP-induced liver injury, as evidenced by decreased serum ALT level, improved survival of mice, decreased hepatic necrosis, inhibition of messenger RNA (mRNA) expression for interferon-gamma (IFN-gamma), Fas ligand (FasL), and chemokines including KC (Keratinocyte-derived chemokine); MIP-1 alpha (macrophage inflammatory protein-1 alpha); MCP-1 (monocyte chemoattractant protein-1); IP-10 (interferon-inducible protein); Mig (monokine induced by IFN-gamma) and decreased neutrophil accumulation in the liver. Hepatic NK and NKT cells were identified as the major source of IFN-gamma by intracellular cytokine staining. APAP induced much less liver injury in Fas-deficient (lpr) and FasL-deficient (gld) mice compared with that in wild-type mice. CONCLUSIONS NK and NKT cells play a critical role in the progression of APAP-induced liver injury by secreting IFN-gamma, modulating chemokine production and accumulation of neutrophils, and up-regulating FasL expression in the liver, all of which may promote the inflammatory response of liver innate immune system, thus contributing to the severity and progression of liver injury downstream of the metabolism of APAP and depletion of reduced glutathione (GSH) in hepatocytes. [source] Chemokine receptor-dependent alloresponsesIMMUNOLOGICAL REVIEWS, Issue 1 2003Wayne W. Hancock Summary:, Immunologists have typically viewed alloreactivity schematically as a function of antigen presentation, expansion of alloreactive T and B cells within regional lymphoid tissues, and cellular infiltration and destruction of an allograft. Actual details of the steps between immune activation and accumulation of effector cells within a graft typically have not received much attention. However, just how cells ,know' to move to and migrate within a graft or not is proving to be of increasing interest, as the chemokine-dependent mechanisms underlying leukocyte recruitment to a transplant are dissected. Experimentally, chemokine receptor targeting can prolong or induce permanent allograft survival, despite preservation of alloresponses within secondary lymphoid tissues, whereas current immunosuppressive protocols have only modest effects on chemokine production and leukocyte homing. Recent knowledge of the chemokine-dependent nature of allograft rejection, acceptance, and tolerance induction are presented as a basis for understanding the rationale for preclinical trials of chemokine receptor-targeted therapies currently underway in primate recipients of solid organ allografts. [source] Histamine and prostaglandin E2 up-regulate the production of Th2-attracting chemokines (CCL17 and CCL22) and down-regulate IFN-,-induced CXCL10 production by immature human dendritic cellsIMMUNOLOGY, Issue 4 2006Anne McIlroy Summary Effector memory T helper 2 (Th2) cells that accumulate in target organs (i.e. skin or bronchial mucosa) have a central role in the pathogenesis of allergic disorders. To date, the factors that selectively trigger local production of Th2-attracting chemokines remain poorly understood. In mucosa, at the sites of allergen entry, immature dendritic cells (DC) are in close contact with mast cells. Histamine and prostaglandin E2 (PGE2) are two mediators released by allergen-activated mast cells that favour the polarization of maturing DC into Th2-polarizing cells. We analysed here the effects of histamine and PGE2 on the prototypic, Th2-(CCL17, CCL22) versus Th1-(CXCL10) chemokine production by human DC. We report that histamine and PGE2 dose-dependently up-regulate CCL17 and CCL22 by monocyte-derived immature DC. These effects were potentiated by tumour necrosis factor-,, still observed in the presence of the Th1-cytokine interferon-, (IFN-,) and abolished by the immunomodulatory cytokine interleukin-10. In addition, histamine and PGE2 down-regulated IFN-,-induced CXCL10 production by monocyte-derived DC. These properties of histamine and PGE2 were observed at the transcriptional level and were mediated mainly through H2 receptors for histamine and through EP2 and EP4 receptors for PGE2. Finally, histamine and PGE2 also up-regulated CCL17 and CCL22 and decreased IFN-,-induced CXCL10 production by purified human myeloid DC. In conclusion, these data show that, in addition to polarizing DC into mature cells that promote naïve T-cell differentiation into Th2 cells, histamine and PGE2 may act on immature DC to trigger local Th2 cell recruitment through a selective control of Th1/Th2-attracting chemokine production, thereby contributing to maintain a microenvironment favourable to persistent immunoglobulin E synthesis. [source] Suppressive effects of cyclosporine A on neutrophils and T cells may be related to therapeutic benefits in patients with steroid-resistant ulcerative colitisINFLAMMATORY BOWEL DISEASES, Issue 1 2002Kenji Ina Abstract An intravenous infusion of cyclosporine A (CsA) shows clinical benefits in patients with steroid-resistant ulcerative colitis (UC). To clarify its mechanisms, we investigated the ability of CsA to inhibit the functions of neutrophils and T cells. The cytotoxic activity by mucosal T cells was analyzed by anti-CD3-triggered cytotoxicity after lamina propria mononuclear cells were cultured with recombinant interleukin (IL)-2. The chemotactic response, the generation of superoxide, and the production of chemokines, IL-8, and macrophage inflammatory protein-1, by neutrophils were examined using a multiple-well chamber assay, a chemiluminescence method, and an enzyme-linked immunosorbent assay (ELISA), respectively. Mucosal chemokine activity was determined by an ELISA using the organ culture supernatant of mucosal biopsy tissues. Pretreatment with CsA caused consistent inhibitions of cytotoxic activity by mucosal T cells and chemotactic migration, superoxide generation, and chemokine production by neutrophils mostly in a dose-dependent manner. In patients who received an intravenous infusion of CsA, mucosal chemokine activity decreased after therapy in parallel with decreases in the numbers of neutrophils and mononuclear cells in the biopsy tissues. These results suggest that suppressive effects of CsA on neutrophils and T cells may be related to therapeutic benefits in patients with steroid-resistant UC. [source] Effect of mitogen-activated protein kinases on chemokine synthesis induced by substance P in mouse pancreatic acinar cellsJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 6 2007Raina Devi Ramnath Abstract Substance P, acting via its neurokinin 1 receptor (NK1 R), plays an important role in mediating a variety of inflammatory processes. Its interaction with chemokines is known to play a crucial role in the pathogenesis of acute pancreatitis. In pancreatic acinar cells, substance P stimulates the release of NF,B-driven chemokines. However, the signal transduction pathways by which substance P-NK1 R interaction induces chemokine production are still unclear. To that end, we went on to examine the participation of mitogen-activated protein kinases (MAPKs) in substance P-induced synthesis of pro-inflammatory chemokines, monocyte chemoanractant protein-1 (MCP-I), macrophage inflammatory protein-l, (MIP-l,) and macrophage inflammatory protein-2 (MIP-2), in pancreatic acini. In this study, we observed a time-dependent activation of ERK1/2, c-Jun N-terminal kinase (JNK), NF,B and activator protein-1 (AP-1) when pancreatic acini were stimulated with substance P. Moreover, substance P-induced ERK 1/2, JNK, NF,B and AP-1 activation as well as chemokine synthesis were blocked by pre-treatment with either extracellular signal-regulated protein kinase kinase 1 (MEK1) inhibitor or JNK inhibitor. In addition, substance P-induced activation of ERK 112, JNK, NF,B and AP-1-driven chemokine production were attenuated by CP96345, a selective NK1 R antagonist, in pancreatic acinar cells. Taken together, these results suggest that substance P-NK1 R induced chemokine production depends on the activation of MAPKs-mediated NF,B and AP-1 signalling pathways in mouse pancreatic acini. [source] Murine and human Langerhans cells express a functional histamine H4 receptor: modulation of cell migration and functionALLERGY, Issue 7 2010M. Gschwandtner To cite this article: Gschwandtner M, Rossbach K, Dijkstra D, Bäumer W, Kietzmann M, Stark H, Werfel T, Gutzmer R. Murine and human Langerhans cells express a functional histamine H4 receptor: modulation of cell migration and function. Allergy 2010; 65: 840,849. Abstract Background:, Histamine is an important mediator of allergic reactions, and recent studies indicated that the function of different types of antigen presenting cells (APC) can be modulated by histamine, in particular via the newly described histamine H4 receptor (H4R). Therefore, we investigated possible interactions of histamine via the H4R on Langerhans cells (LC), which represent the professional APC in the skin and therefore have an important role in the initiation and maintenance of allergic skin diseases. Methods:, The expression of the H4R was evaluated by real-time PCR, flow cytometry and immunofluorescence staining. The function of the H4R was determined by intracellular flow cytometric measurement of chemokine production and LC migration assays. Results:, Here, we show H4R expression on in vitro generated monocyte-derived LC (mRNA and protein) and on primary LC from murine and human skin samples (protein). The immunofluorescence staining in murine and human skin samples clearly proved that LC express the H4R in situ. Stimulation with histamine or a H4R agonist downregulated the chemokine (C-C motif) ligand 2 (CCL2) in human monocyte-derived LC and primary LC. Prestimulation with a selective H4R antagonist abolished this effect. Moreover, migration of LC from the epidermis was increased after H4R agonist stimulation in ex vivo migration assays using human epidermis and murine in vivo assays. Conclusion:, Our findings show that LC express a functional H4R and point towards a possible pathogenic relevance of the H4R in inflammatory and allergic diseases. [source] Mechanical strain increases cytokine and chemokine production in bronchial fibroblasts from asthmatic patientsALLERGY, Issue 1 2009F. Le Bellego Background:, Mechanical strain and cytokine stimulation are two important mechanisms leading to airway remodeling in asthma. The effect of mechanical strain on cytokine secretion in airway fibroblasts is not known. The aim of this study was to determine whether bronchial and nasal fibroblasts differentially alter cytokine secretion in response to mechanical strain. Methods:, We measured secretion of the pro-fibrotic cytokine, interleukin-6 (IL-6), and the pro-inflammatory cytokines, IL-8 and monocyte chemotactic protein 1, before and after mechanical strain in bronchial fibroblasts obtained from asthmatic patients [asthmatic bronchial fibroblasts (BAF)] and normal volunteers [normal bronchial fibroblasts (BNF)], and in nasal fibroblasts (NF) obtained from nasal polyps. Cells were grown on flexible membranes and a mechanical strain of 30% amplitude, 1 Hz frequency was applied for 3, 6 and 24 h. Control cells were unstrained. IL-6, IL-8 and monocyte chemotactic protein 1 was measured after 24 h strain using enzyme-linked immunoassay; mRNA was measured by real time polymerase chain reaction. We also measured mRNA for versican, a matrix proteoglycan, known to be upregulated in the asthmatic airway wall. Results:, In unstrained conditions, no differences in cytokine secretion were observed. After 24 h strain, BAF secreted more IL-6 than BNF. Mechanical strain increased IL-8 mRNA in BAF, BNF and NF; and IL-6 and versican mRNA, in BAF, only. Conclusions:, Cytokine responses to mechanical strain varied in different airway fibroblast populations, and depended on the site of origin, and the underlying inflammatory state. Strain resulted in IL-6 upregulation and increased message for extracellular matrix protein in bronchial fibroblasts from asthmatic patients only, and may reflect these patients' propensity for airway remodeling. [source] Oxidative stress due to anesthesia and surgical trauma: Importance of early enteral nutritionMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 6 2009Katerina Kotzampassi Abstract Anesthesia and surgical trauma are considered major oxidative and nitrosative stress effectors resulting in the development of SIRS. In this study we evaluated the usefulness of early enteral nutrition after surgical trauma. Sixty male Wistar rats were subjected to midline laparotomy and feeding-gastrostomy. Twenty of these rats served as controls after recovering from the operation stress. The remaining rats received, through gastrostomy, enteral nutrition or placebo-feeding for 24 h. Oxidative stress markers and CC chemokine production were evaluated in rat serum and liver tissue. The operation itself was found to increase nitric oxide (NO) and malondialdehyde (MDA) and to decrease superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), as well as liver tissue energy charge (EC) in relation to controls. The rats receiving enteral feeding exhibited statistically significantly lower levels of NO and MDA, and higher levels of SOD, GSH-Px, and liver EC, in relation to placebo feeding rats. The operation significantly increased the chemokines monocyte chemoattractant protein (MCP)-1 and regulated upon activation, normal T-cell expressed, and secreted (RANTES) in rat serum, while enteral nutrition caused a further significant increase in chemokine levels in serum. mRNA chemokine expression in liver was increased in a similar pattern. These findings indicate that early enteral feeding might play an important role after surgery ameliorating oxidative stress, affecting positively the hepatic EC and regulating, via chemokine production, cell trafficking, and healing process. [source] Effects of oral commensal and pathogenic bacteria on human dendritic cellsMOLECULAR ORAL MICROBIOLOGY, Issue 2 2009T. Chino Background/aims:, The oral cavity harbors a diverse and complex microbial community. Bacteria accumulate on both the hard and soft oral tissues in sessile biofilms and engage the host in an intricate cellular dialog, which normally constrains the bacteria to a state of commensal harmony. Dendritic cells (DCs) are likely to balance tolerance and active immunity to commensal microorganisms as part of chronic inflammatory responses. While the role played by DCs in maintaining intestinal homeostasis has been investigated extensively, relatively little is known about DC responses to oral bacteria. Methods:, In this study, we pulsed human monocyte-derived immature DCs (iDCs) with cell wall extracts from pathogenic and commensal gram-positive or gram-negative oral bacteria. Results:, Although all bacterial extracts tested induced iDCs to mature and produce cytokines/chemokines including interleukin-12p40, tumor necrosis factor-,, and monocyte chemoattractant protein-1 (MCP-1), the most important factor for programming DCs by oral bacteria was whether they were gram-positive or gram-negative, not whether they were commensal or pathogenic. In general, gram-negative oral bacteria, except for periodontopathic Porphyromonas gingivalis, stimulated DC maturation and cytokine production at lower concentrations than gram-positive oral bacteria. The threshold of bacteria needed to stimulate chemokine production was 100-fold to 1000-fold lower than that needed to induce cytokines. In addition, very low doses of oral commensal bacteria triggered monocytes to migrate toward DC-derived MCP-1. Conclusion:, Oral commensal and pathogenic bacteria do not differ qualitatively in how they program DCs. DC-derived MCP-1 induced in response to oral commensal bacteria may play a role, at least in part, in the maintenance of oral tissue integrity by attracting monocytes. [source] Filaria/Wolbachia activation of dendritic cells and development of Th1-associated responses is dependent on Toll-like receptor 2 in a mouse model of ocular onchocerciasis (river blindness)PARASITE IMMUNOLOGY, Issue 9 2007K. DAEHNEL SUMMARY Toll-like receptors (TLRs) regulate dendritic cell function and activate signals that mediate the nature of the adaptive immune response. The current study examined the role of TLRs in dendritic cell activation and in regulating T cell and antibody responses to antigens from the filarial parasites Onchocerca volvulus and Brugia malayi, which cause river blindness and lymphatic filariasis, respectively. Bone-marrow-derived CD11c+ cells from C57BL/6 and TLR4,/, mice produced high levels of IL-6 and RANTES, and showed elevated surface CD40 expression, whereas CD11c+ cells from myeloid differentiation factor 88,/, (MyD88,/,), TLR2,/, and TLR2/4,/, mice were not activated. Similarly, IFN-, production by splenocytes from immunized TLR2,/, mice was significantly impaired compared with splenocytes from C57BL/6 and TLR4,/, mice. In contrast, there was no difference among these strains in Th2-associated responses including IL-5 production by splenocytes from immunized animals, serum IgE and IgG1, or eosinophil infiltration into the corneal stroma. Neutrophil recruitment to the cornea and CXC chemokine production was inhibited in immunized TLR2,/, mice compared with C57BL/6 and TLR4,/, mice. Taken together, these findings demonstrate an essential role for TLR2 in filaria-induced dendritic cell activation, IFN-, production and neutrophil migration to the cornea, but does not affect filaria-induced Th2-associated responses. [source] A20 suppresses inflammatory responses and bone destruction in human fibroblast-like synoviocytes and in mice with collagen-induced arthritisARTHRITIS & RHEUMATISM, Issue 8 2010Young-Sool Hah Objective Nuclear factor-,B (NF-,B) has been implicated as a therapeutic target for the treatment of rheumatoid arthritis (RA). The purpose of this study was to determine whether A20, a universal inhibitor of NF-,B, might have antiarthritic effects. Methods An adenovirus containing A20 complementary DNA (AdA20) was used to deliver A20 to human rheumatoid fibroblast-like synoviocytes (FLS) in vitro as well as to mice with collagen-induced arthritis (CIA) in vivo via intraarticular injection into the ankle joints bilaterally. Results In vitro experiments demonstrated that AdA20 suppressed NF-,B activation, chemokine production, and matrix metalloproteinase secretion induced by tumor necrosis factor , in FLS. Mice with CIA that were treated with AdA20 had a lower cumulative disease incidence and severity of arthritis, based on hind paw thickness, radiologic and histopathologic findings, and inflammatory cytokine levels, than did control virus,injected mice. The protective effects of AdA20 were mediated by the inhibition of the NF-,B signaling pathway. The severity of arthritis was also significantly decreased in the untreated front paws, indicating a beneficial systemic effect of local suppression of NF-,B. Surprisingly, mice treated with AdA20 after the onset of CIA had significantly decreased arthritis severity from the onset of clinical signs to the end of the study. Conclusion These results suggest that using A20 to block the NF-,B pathway in rheumatoid joints reduces both the inflammatory response and the tissue destruction. The development of an immunoregulatory strategy based on A20 may therefore have therapeutic potential in the treatment of RA. [source] Retinoid ameliorates experimental autoimmune myositis, with modulation of Th cell differentiation and antibody production in vivoARTHRITIS & RHEUMATISM, Issue 10 2009Naho Ohyanagi Objective Polymyositis and dermatomyositis are chronic inflammatory muscle diseases. Retinoids are compounds that bind to the retinoic acid binding site of retinoic acid receptors and have biologic activities similar to those of vitamin A. Recent studies indicate that retinoids promote Th2 differentiation and suppress Th1 and Th17 differentiation in vitro. The present study was undertaken to examine the effects of a synthetic retinoid, Am80, on experimental autoimmune myositis as well as on Th phenotype development and antibody production. Methods Experimental autoimmune myositis was induced in SJL/J mice by immunization with rabbit myosin. Am80 was administered orally once daily. Its effects were evaluated by measurement of the numbers of infiltrating inflammatory cells, production of inflammatory cytokines in muscle, production of Th-specific cytokines by myosin-stimulated splenic T cells, and production of antimyosin antibodies in serum. Results In mice with experimental autoimmune myositis, orally administered Am80 significantly reduced the number of infiltrating inflammatory cells and the expression of tumor necrosis factor , and interleukin-1, (IL-1,) in muscle. Moreover, Am80 increased production of interferon-,, IL-4, and IL-10, but not IL-17, by myosin-stimulated splenic T cells of mice with experimental autoimmune myositis, suggesting that it could enhance differentiation into Th1 and Th2, but not Th17, in vivo. Am80 also decreased serum levels of IgG2a and IgG2b antimyosin antibodies, but did not affect levels of IgG1 antimyosin antibodies. In addition, it suppressed chemokine expression and activator protein 1 activity in myoblasts in vitro. Conclusion The synthetic retinoid Am80 has an inhibitory effect on experimental autoimmune myositis. It might regulate the development of Th phenotype and antibody production in vivo, in addition to its effects on cytokine and chemokine production. [source] Galectin 3 induces a distinctive pattern of cytokine and chemokine production in rheumatoid synovial fibroblasts via selective signaling pathwaysARTHRITIS & RHEUMATISM, Issue 6 2009Andrew Filer Objective High expression of galectin 3 at sites of joint destruction in rheumatoid arthritis (RA) suggests that galectin 3 plays a role in RA pathogenesis. Previous studies have demonstrated the effects of galectins on immune cells, such as lymphocytes and macrophages. This study was undertaken to investigate the hypothesis that galectin 3 induces proinflammatory effects in RA by modulating the pattern of cytokine and chemokine production in synovial fibroblasts. Methods Matched samples of RA synovial and skin fibroblasts were pretreated with galectin 3 or tumor necrosis factor , (TNF,), and the levels of a panel of cytokines, chemokines, and matrix metalloproteinases (MMPs) were determined using enzyme-linked immunosorbent assays and multiplex assays. Specific inhibitors were used to dissect signaling pathways, which were confirmed by Western blotting and NF-,B activation assay. Results Galectin 3 induced secretion of interleukin-6 (IL-6), granulocyte,macrophage colony-stimulating factor, CXCL8, and MMP-3 in both synovial and skin fibroblasts. By contrast, galectin 3,induced secretion of TNF,, CCL2, CCL3, and CCL5 was significantly greater in synovial fibroblasts than in skin fibroblasts. TNF, blockade ruled out autocrine TNF,-stimulated induction of chemokines. The MAPKs p38, JNK, and ERK were necessary for IL-6 production, but phosphatidylinositol 3-kinase (PI 3-kinase) was required for selective CCL5 induction. NF-,B activation was required for production of both IL-6 and CCL5. Conclusion Our findings indicate that galectin 3 promotes proinflammatory cytokine secretion by tissue fibroblasts. However, galectin 3 induces the production of mononuclear cell,recruiting chemokines uniquely from synovial fibroblasts, but not matched skin fibroblasts, via a PI 3-kinase signaling pathway. These data provide further evidence of the role of synovial fibroblasts in regulating the pattern and persistence of the inflammatory infiltrate in RA and suggest a new and important functional consequence of the observed high expression of galectin 3 in the rheumatoid synovium. [source] Effective therapy for nephritis in (NZB × NZW)F1 mice with triptolide and tripdiolide, the principal active components of the Chinese herbal remedy Tripterygium wilfordii Hook FARTHRITIS & RHEUMATISM, Issue 6 2008Xuelian Tao Objective Triptolide and tripdiolide are thought to be active components of the Chinese antirheumatic herbal remedy Tripterygium wilfordii Hook F, which has been shown to be effective in treating murine lupus nephritis. This study was undertaken to examine the therapeutic effect of triptolide and tripdiolide on established lupus nephritis in (NZB × NZW)F1 mice. Methods (NZB × NZW)F1 mice were treated with vehicle, triptolide, or tripdiolide for 15 weeks beginning at the age of 29 weeks (after the development of lupus nephritis). Body weight, proteinuria, and anti,double-stranded DNA (anti-dsDNA) antibodies were monitored, and the kidney and spleen were assessed histologically. Culture supernatants of spleen mononuclear cells were assayed for cytokines. Results By 28 weeks, most (NZB × NZW)F1 mice had developed lupus nephritis. Vehicle-treated mice exhibited progressive proteinuria, hypoalbuminemia, elevated blood urea nitrogen (BUN) levels, and evidence of severe nephritis. In contrast, proteinuria and BUN levels were significantly reduced in mice treated with either triptolide or tripdiolide as compared with those treated with vehicle. There was no hypoalbuminemia or apparent evidence of lupus nephritis in mice treated with either of the 2 diterpenoids. At 44 weeks of age, the survival rate in mice treated with vehicle (35.7%) was markedly lower than that in mice treated with either triptolide (87.5%) or tripdiolide (88.2%). The mean level of anti-dsDNA antibody in mice treated with tripdiolide was lower than that in the vehicle-treated mice upon completion of the treatment course. Production of tumor necrosis factor, interleukin-6, and monocyte chemoattractant protein 1 by spleen cells was also decreased after diterpenoid therapy. Conclusion Therapy with triptolide or tripdiolide significantly ameliorated lupus nephritis in (NZB × NZW)F1 mice, reduced cytokine and chemokine production, and prolonged survival. [source] Genetic association of vasoactive intestinal peptide receptor with rheumatoid arthritis: Altered expression and signal in immune cellsARTHRITIS & RHEUMATISM, Issue 4 2008Mario Delgado Objective Vasoactive intestinal peptide (VIP) has been shown to be one of the endogenous factors involved in the maintenance of immune tolerance. Administration of VIP ameliorates clinical signs in various experimental autoimmune disorders. This study was undertaken to investigate whether the exacerbated inflammatory autoimmune response in rheumatoid arthritis (RA) might result directly from altered expression and/or signaling of VIP receptors in immune cells. Methods The effect of specific agonists of different VIP receptors on collagen-induced arthritis in mice was investigated by clinical and histologic assessment and measurement of cytokine and chemokine production. Expression of VIP receptor type 1 (VPAC1) in synovial cells and monocytes from RA patients was determined by flow cytometry. Potential associations of VPAC1 genetic polymorphisms with RA susceptibility were investigated. Results A VPAC1 agonist was very efficient in the treatment of experimental arthritis, and deficient expression of VPAC1 in immune cells of RA patients was associated with the predominant proinflammatory Th1 milieu found in this disease. Immune cells derived from RA patients were less responsive to VIP signaling than were cells from healthy individuals and showed reduced VIP-mediated immunosuppressive activity, rendering leukocytes and synovial cells more proinflammatory in RA. A significant association between multiple-marker haplotypes of VPAC1 and susceptibility to RA was found, suggesting that the reduced VPAC1 expression in RA-derived immune cells is associated with the described VPAC1 genetic polymorphism. Conclusion These findings are highly relevant to the understanding of RA pathogenesis. They suggest that VIP signaling through VPAC1 is critical to maintaining immune tolerance in RA. In addition, the results indicate that VPAC1 may be a novel therapeutic target in RA. [source] The protein kinase C agonist PEP005 increases NF-,B expression, induces differentiation and increases constitutive chemokine release by primary acute myeloid leukaemia cellsBRITISH JOURNAL OF HAEMATOLOGY, Issue 6 2009Astrid Marta Olsnes Summary Acute myeloid leukaemia (AML) cells show constitutive release of several chemokines that occurs in three major clusters: (I) chemokine (C-C motif) ligand (CCL)2,4/chemokine (C-X-C motif) ligand (CXCL)1/8, (II) CCL5/CXCL9,11 and (III) CCL13/17/22/24/CXCL5. Ingenol-3-angelate (PEP005) is an activator of protein kinase C and has antileukaemic and immunostimulatory effects in AML. We investigated primary AML cells derived from 35 unselected patients and determined that PEP005 caused a dose-dependent increase in the release of chemokines from clusters I and II, including several T cell chemotactic chemokines. The release of granulocyte-macrophage colony-stimulating factor and hepatocyte growth factor was also increased. CCL2,4/CXCL1/8 release correlated with nuclear factor (NF)-,B expression in untreated AML cells, and PEP005-induced chemokine production was associated with further increases in the expression of the NF-,B subunits p50, p52 and p65. Increased DNA binding of NF-,B was observed during exposure to PEP005, and the specific NF-,B inhibitor BMS-345541 reduced constitutive chemokine release even in the presence of PEP005. Finally, PEP005 decreased expression of stem cell markers (CD117, CXCR4) and increased lineage-associated CD11b and CD14 expression. To conclude, PEP005 has a unique functional pharmacological profile in human AML. Previous studies have described proapoptotic and T cell stimulatory effects and the present study describes additional T cell chemotactic and differentiation-inducing effects. [source] Vitamin D and glucocorticoids differentially modulate chemokine expression in human airway smooth muscle cellsBRITISH JOURNAL OF PHARMACOLOGY, Issue 1 2008A Banerjee Background and purpose: Chemokines play a critical role in the pathogenesis of asthma and facilitate the recruitment of inflammatory cells in the airways. Evidence now suggests that airway smooth muscle (ASM) may serve as a source of chemokines in inflamed airways. Although vitamin D has potent anti-inflammatory properties in vitro in some cell types, its effects on ASM cells remain unclear. Here, we investigated whether 1,, 25-dihydroxy vitamin D3 (calcitriol) modulated chemokine production in ASM. Experimental approach: Human ASM cell cultures were derived from tracheal samples taken during surgery. ASM cells were treated with tumour necrosis factor alpha (TNF,) and/or interferon gamma (IFN,) for 24 h in the presence of calcitriol and/or the glucocorticoid fluticasone added 2 h before. RANTES (regulated upon activation, normal T-cell expressed and secreted), interferon-inducible protein 10 (IP-10) and fractalkine (FKN) levels in cell supernatants were measured by ELISA. Key results: In TNF,-treated cells, calcitriol inhibited RANTES and IP-10 secretion in a concentration-dependent manner. FKN levels were negligible. In TNF,/IFN,-treated cells, whereas fluticasone or calcitriol alone partially inhibited RANTES secretion (by 38 and 20%, respectively), the combination of both drugs additively inhibited RANTES secretion (by 60%). No effect was observed on IP-10 secretion. Whereas fluticasone enhanced FKN secretion (by 50%), calcitriol significantly decreased FKN levels (by 50%). Interestingly, calcitriol blocked the stimulatory effect of fluticasone on FKN secretion, which was inhibited by 60% with the combination of calcitriol and fluticasone. Conclusions and implications: These findings suggest that vitamin D uniquely modulates human ASM expression of chemokines and may exert some beneficial effects in the treatment of steroid-resistant patients with asthma. British Journal of Pharmacology (2008) 155, 84,92; doi:10.1038/bjp.2008.232; published online 16 June 2008 [source] Inhibition of LPS-induced chemokine production in human lung endothelial cells by lipid conjugates anchored to the membraneBRITISH JOURNAL OF PHARMACOLOGY, Issue 7 2002G Ch Beck In acute respiratory distress syndrome (ARDS) induced by endotoxins, a high production of inflammatory mediators by microvascular lung endothelial cells (LMVEC) can be observed. Activation of cells by endotoxins may result in elevated secretion of phospholipase A2 (sPLA2) which is thought to contribute to tissue damage. The present study was undertaken to investigate the role of sPLA2 in chemokine production in human lung microvascular endothelial cells (LMVEC) stimulated with the endotoxins lipopolysaccharide (LPS) and lipoteichoic acid (LTA). In particular, we investigated the effects of sPLA2 inhibitors, specifically, the extracellular PLA2 inhibitors (ExPLIs), composed of N-derivatized phosphatidyl-ethanolamine linked to polymeric carriers, and LY311727, a specific inhibitor of non-pancreatic sPLA2. ExPLIs markedly inhibited LPS and LTA induced production and mRNA expression of the neutrophile attracting chemokines IL-8, Gro-, and ENA-78, as well as of the adhesion molecules ICAM-1 and E-selectin. Concomitantly, ExPLIs inhibited the LPS-induced activation of NF-,B by LPS but not its activation by TNF-, or IL-1. Endotoxin mediated chemokine production in LMVEC seems not to involve PLA2 activity, since LPS stimulation was not associated with activation of intracellular or secreted PLA2. It therefore seems that the inhibitory effect of the ExPLIs was not due to their PLA2 inhibiting capacity. This was supported by the finding that the LPS-induced chemokine production was not affected by the selective sPLA2 inhibitor LY311727. It is proposed that the ExPLIs may be considered a prototype of potent suppressors of specific endotoxin-induced inflammatory responses, with potential implications for the therapy of subsequent severe inflammation. British Journal of Pharmacology (2002) 135, 1665,1674; doi:10.1038/sj.bjp.0704618 [source] Immunoreactivity profile of peripheral blood mononuclear cells from patients with ragweed-induced allergic rhinitisCLINICAL & EXPERIMENTAL ALLERGY, Issue 6 2007J. Sun Summary Background Seasonal rhinitis is manifested by a series of nasal symptoms in response to exposure to seasonal allergens including ragweed pollen. Understanding its immunological mechanisms may help to better manage the disease. Objective We sought to determine comprehensively ragweed-induced cytokine and chemokine production by peripheral blood mononuclear cells from normal individuals and patients with seasonal rhinitis sensitized to ragweed pollen, and to assess its regulation by exogenous IL-10. Methods Cells were cultured in the presence or absence of a purified ragweed pollen extract with or without exogenous IL-10. Cytokines and chemokines were measured in the supernatant. Gene expression was evaluated using real-time quantitative reverse transcription PCR. Results Ragweed stimulation significantly increased the production of the Th2-associated cytokines IL-5, IL-9 and IL-13, the chemokines CCL17 and CCL22 and the regulatory cytokine IL-10 in allergic patients, whereas transforming growth factor-, (TGF-,) production was increased only in normal individuals. No difference was detected between groups in the production of the Th1 cytokine IFN-, or the Th1-affiliated chemokines CXCL10 and CXCL11. Exogenous IL-10 significantly suppressed spontaneous and induced production of both Th1- and Th2-associated cytokines and chemokines. Conclusion Our work demonstrated that locally manifested allergic rhinitis is underlined by a systemic Th2 immune response specific to allergens. The molecular pathogenesis of allergic rhinitis may be linked to a compromised allergen-specific immune regulation, e.g., reduced spontaneous and allergen-induced TGF-, production in patients compared with healthy controls. Our data also show that IL-10 inhibits both the effector and directional mechanisms of allergen-specific immune response, further supporting its potential therapeutic benefit in preventing and treating allergic diseases. [source] Anti-inflammatory properties of heat shock protein 70 and butyrate on Salmonella -induced interleukin-8 secretion in enterocyte-like Caco-2 cellsCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 1 2005J. J. Malago Summary Intestinal epithelial cells secrete the chemokine interleukin (IL)-8 in the course of inflammation. Because heat shock proteins (Hsps) and butyrate confer protection to enterocytes, we investigated whether they modulate Salmonella enterica serovar Enteritidis (S. serovar Enteritidis)-induced secretion of IL-8 in enterocyte-like Caco-2 cells. Caco-2 cells incubated with or without butyrate (0,20 m M, 48 h) were infected with S. serovar Enteritidis after (1 h at 42°C, 6 h at 37°C) or without prior heat shock (37°C). Levels of Hsp70 production and IL-8 secretion were analysed using immunostaining of Western blots and enzyme-linked immunosorbent assay (ELISA), respectively. The cells secreted IL-8 in response to S. serovar Enteritidis and produced Hsp70 after heat shock or incubation with butyrate. The IL-8 secretion was inhibited by heat shock and butyrate concentrations as low as 0·2 m M for crypt-like and 1 m M for villous-like cells. In a dose-dependent manner, higher butyrate concentrations enhanced IL-8 secretion to maximal levels followed by a gradual but stable decline. This decline was associated with increasing production of Hsp70 and was more vivid in crypt-like cells. In addition, the higher concentrations abolished the heat shock inhibitory effect. Instead, they promoted the IL-8 production in heat-shocked cells even in the absence of S. serovar Enteritidis. We conclude that heat shock and low concentrations of butyrate inhibit IL-8 production by Caco-2 cells exposed to S. serovar Enteritidis. Higher butyrate concentrations stimulate the chemokine production and override the inhibitory effect of the heat shock. The IL-8 down-regulation could in part be mediated via production of Hsp70. [source] | |||||||||||||||||||||||||