IP-10 Secretion Research Articles

Effects of acute ethanol exposure on cytokine production by primary airway smooth muscle cells

Both chronic and binge alcohol abuse can be significant risk factors for inflammatory lung diseases such as acute respiratory distress syndrome and chronic obstructive pulmonary disease. However, metabolic basis of alcohol-related lung disease is not well defined, and may include key metabolites of ethanol [EtOH] in addition to EtOH itself. Therefore, we investigated the effects of EtOH, acetaldehyde [ACE], and fatty acid ethyl esters [FAEEs] on oxidative stress, endoplasmic reticulum (ER) stress, AMP-activated protein kinase (AMPK) signaling and nuclear translocation of phosphorylated (p)-NF-κB p65 in primary human airway smooth muscle (HASM) cells stimulated to produce cytokines using LPS exposure. Both FAEEs and ACE induced evidence of cellular oxidative stress and ER stress, and increased p-NF-κB in nuclear extracts. EtOH and its metabolites decreased p-AMPKα activation, and induced expression of fatty acid synthase, and decreased expression of sirtuin 1. In general, EtOH decreased secretion of IP-10, IL-6, eotaxin, GCSF, and MCP-1. However, FAEEs and ACE increased these cytokines, suggesting that both FAEEs and ACE as compared to EtOH itself are proinflammatory. A direct effect of EtOH could be consistent with blunted immune response. Collectively, these two features of EtOH exposure, coupled with the known inhibition of innate immune response in our model might explain some clinical manifestations of EtOH exposure in the lung.

Comparing the Primary and Recall Immune Response Induced by a New EV71 Vaccine Using Systems Biology Approaches.

Three inactivated EV71 whole-virus vaccines have completed Phase III clinical trials in mainland China, with high efficacy, satisfactory safety, and sustained immunogenicity. However, the molecular mechanisms how this new vaccine elicit potent immune response remain poorly understood. To characterize the primary and recall responses to EV71 vaccines, PBMC from 19 recipients before and after vaccination with EV71 vaccine are collected and their gene expression signatures after stimulation with EV71 antigen were compared. The results showed that primary and recall response to EV71 antigen have both activated an IRF7 regulating type I interferon and antiviral immune response network. However, up-regulated genes involved in T cell activation regulated by IRF1, inflammatory response, B-cell activation and humoral immune response were only observed in recall response. The specific secretion of IL-10 in primary response and IL-2,IP-10,CCL14a, CCL21 in recall response was consistent with the activation of immune response process found in genes. Furthermore, the expression of MX1 and secretion of IP-10 in recall response were strongly correlated with NTAb level at 180d after vaccination (r = 0.81 and 0.99). In summary, inflammatory response, adaptive immune response and a stronger antiviral response were indentified in recall response.

Expression and functionality of Toll- and RIG-like receptors in HepaRG cells

HepaRG cells are considered as the best surrogate model to primary human hepatocyte (PHH) culture to investigate host-pathogen interactions. Yet their innate immune functions remain unknown. In this study, we explored the expression and functionality of Toll-like (TLR) and retinoic acid-inducible gene-1 (RIG-I)-like receptors (RLR) in these cells. Gene and protein expression levels of TLR-1 to 9 and RLR in HepaRG were mainly compared to PHH, by RT-qPCR, FACS, and Western blotting. Their functionality was assessed, by measuring the induction of toll/rig-like themselves and several target innate gene expressions, as well as the secretion of IL-6, IP-10, and type I interferon (IFN), upon agonist stimulation. Their functionality was also shown by measuring the antiviral activity of some TLR/RLR agonists against hepatitis B virus (HBV) infection. The basal gene and protein expression profile of TLR/RLR in HepaRG cells was similar to PHH. Most receptors, except for TLR-7 and 9, were expressed as proteins and functionally active as shown by the induction of some innate genes, as well as by the secretion of IL-6 and IP-10, upon agonist stimulation. The highest levels of IL-6 and IP-10 secretion were obtained by TLR-2 and TLR-3 agonist stimulation respectively. The highest preventive anti-HBV activity was obtained following TLR-2, TLR-4 or RIG-I/MDA-5 stimulations, which correlated with their high capacity to produce both cytokines. Our results indicate that HepaRG cells express a similar pattern of functional TLR/RLR as compared to PHH, thus qualifying HepaRG cells as a surrogate model to study pathogen interactions within a hepatocyte innate system.

29 Airway epithelial cell IP-10 production is regulated by miR-31 via the transcription factor IRF-1

The C-X-C motif chemokine 10 (CXCL10) or interferon gamma-induced protein 10 (IP-10) is a pro-inflammatory cytokine which has been attributed to many roles including cellular activation and migration. The activity of this cytokine is mediated by binding to the CXCR3 receptor primarily on T cells, natural killer cells, macrophages and also neutrophils. IP-10 is produced by a wide variety of inflammatory cells and also airway epithelia. Previous work has shown that increased levels of IP-10 are present in bronchoalveolar lavage fluid from patients with CF. In this study, we evaluated IP-10 levels in CF pulmonary epithelial cells and found that IP-10 expression and production were significantly increased in CF tracheal and bronchial epithelial cell lines compared to non-CF controls. The transcription factor IRF-1 has been reported to play a role in the regulation of IP-10 and our recent work has shown that IRF-1 levels are increased in CF pulmonary epithelial cells via dysregulation of the miRNA, miR-31. In agreement with previous work, knockdown of IRF-1 using siRNA significantly decreased expression and secretion of IP-10 from CF bronchial epithelial cells. In addition, overexpression of miR-31 in CF bronchial epithelial cells resulted in a decrease in the levels of IRF-1, which was also associated with a significant decrease in the expression and production of IP-10. These findings suggest that pulmonary epithelial cells may be a potential source of IP-10 in the CF lung via dysregulated miR-31. Further work is required to elucidate the role of elevated IP-10 in the pathogenesis of CF lung disease.

Allyl methyl disulfide inhibits IL-8 and IP-10 secretion in intestinal epithelial cells via the NF-кB signaling pathway.

Garlic and its active constituents have shown versatile medicinal activities in the prevention and treatment of various disorders. Allyl methyl disulfide (AMDS) was identified as one of the major bioactive components in an effective inhalation fork remedy using fresh garlic paste in our previous study. In this work, we investigated the immunological properties of AMDS to elucidate the underlying mechanisms of the fork inhalation treatment using fresh garlic. The inhibition effect of AMDS on TNF-α-induced IL-8 and IP-10 production in intestinal epithelial cell lines HT-29 and Caco-2 was first evaluated. Pretreatment of the cells with AMDS attenuated IL-8 and IP-10 secretion induced by TNF-α in a dose-dependent manner in the non-cytotoxic concentration range of 20 to 150 μM. Mechanistic studies revealed that AMDS suppressed the accumulation of IL-8 mRNA and inhibited IкBα degradation and NF-кB p65 translocation into the nucleus at both the transcriptional and translational levels, suggesting that the attenuation effort of AMDS on cytokine IL-8 secretion might at least be partially related to the NF-κB signaling pathway. These results suggest that AMDS may be a promising phytochemical agent in the treatment of immunological disorders, such as ulcerative colitis, Crohn's disease, intestinal inflammatory diseases and others. In addition, the mechanistic study data indicated that immune modulation could be one of the therapeutic mechanisms of the effective fork treatment containing AMDS as one of the major components.

Quercetin and Resveratrol Decrease the Inflammatory and Oxidative Responses in Human Ocular Surface Epithelial Cells.

To determine the anti-inflammatory and antioxidant effects of quercetin (QCT) and/or resveratrol (RES) on human conjunctival (IOBA-NHC) and corneal (HCE) epithelial cell lines. IOBA-NHC and HCE cells were treated with QCT (0.5-25 μM), RES (0.5-50 μM) and a low-dose mixture of QCT (0.5 μM) and RES (5 μM) (QCT+RES) and stimulated with either TNF-α or ultraviolet (UV)-B radiation. Cytokine production (IL-6, IL-8, IP-10, and VEGF) was analyzed by an immune bead-based array, and intracellular reactive oxygen species (ROS) production was determined by a H2DCF-DA dye assay. Stimulation of IOBA-NHC and HCE cells with TNF-α induced an increase of IL-6, IL-8, and IP-10 secretion in both cell lines. Quercetin and RES decreased IL-6 and IP-10 secretion in a dose-dependent manner in both cell lines. Interleukin-8 secretion was also inhibited in a dose-dependent manner by QCT in HCE, but only at 20 and 25 μM QCT and 50 μM RES in IOBA-NHC and at 50 μM RES in HCE. QCT+RES decreased IL-6 and IL-8 secretion (P < 0.01 and P < 0.05, respectively) in IOBA-NHC cells. Ultraviolet-B induced a significant increase of ROS in both cell lines (P < 0.01 and P < 0.001 for IOBA-NHC and HCE cells, respectively), which was significantly decreased in a dose-dependent manner by QCT and RES in HCE cells. Reactive oxygen species production in IOBA-NHC cells was inhibited (P < 0.05) by 50 μM RES. Quercetin and RES have anti-inflammatory and antioxidant effects on IOBA-NHC and HCE cells. These in vitro data suggest that both polyphenols may have a therapeutic potential in the treatment of inflammatory ocular surface diseases.

Markedly increased IP-10 production by blood-brain barrier in neuromyelitis optica.

ObjectiveSevere damage to the blood-brain barrier (BBB) allows anti-aquaporin 4 (AQP4) antibodies to access the astrocytic endfeet in neuromyelitis optica (NMO). In the current study, we identified the pathogenic cytokines/chemokines that are responsible for the BBB malfunction induced by NMO sera.MethodsWe measured the levels of 27 cytokines/chemokines in human brain microvascular endothelial cells (BMECs) after exposure to sera obtained from patients with the acute and stable phases of anti-AQP4 antibody-positive NMO spectrum disorder (NMOSD), multiple sclerosis (MS) patients and healthy controls (HC) using a multiplexed fluorescent bead-based immunoassay system.ResultsThe induced protein (IP)-10 level in the cells was markedly increased following exposure to acute phase NMOSD sera. Other cytokines/chemokines including interleukin (IL)-6 and monocyte chemotactic protein (MCP)-1 were also significantly increased in the acute NMOSD group compared to both the MS and HC groups. The up-regulation of the IP-10 levels in the cells after exposure to the acute-phase NMOSD sera was also observed using another specified ELISA, and this effect was significantly decreased during the remission phase in the individual NMOSD patients. Furthermore, the increase in the level of IP-10 after exposure to the sera was significantly correlated with the cerebrospinal fluid/serum albumin ratio.ConclusionsSera from the acute phase of NMO markedly increased the autocrine secretion of IP-10 by BMECs. The over-production of IP-10 in BMECs may play an important role in the pathogenesis of NMO and may therefore help to mediate the trafficking of T cells expressing its receptor across the BBB.

Atopic dermatitis and alpha-chemokines.

Many studies have shown the involvement of interferon (IFN)γ-inducible protein 10 (IP-10) and T-helper 1 (Th1) cytokines in Atopic Dermatitis (AD). IFN-γ, tumor necrosis factor (TNF)-α and interleukin (IL)-18 are potent stimulators of the expression and secretion of IP-10 in cultured keratinocytes from AD patients. Apoptosis of keratinocytes, induced mainly by T cells and mediated by IFN-γ, is the essential pathogenetic event in eczema formation. Enhanced IP-10, induced by IFN-γ, and IFN-inducible T cell alpha-chemoattractant (I-TAC) expression has been observed in lesional AD skin. It has been shown that keratinocytes undergoing apoptosis in acute eczematous lesions release chemokines that attract more T cells toward the epidermis, which may further augment the inflammation and keratinocyte apoptosis. Drugs used in the treatment of AD modulate IP-10. Antihistamines are widely used for the treatment of AD; it has been shown in human monocyte-derived dendritic cells (MoDCs) and autologous CD4+ T cells that antihistamines inhibited the production of IP-10 and�� monokine induced by IFN-gamma (MIG) expressions. It has been also shown that antimycotics and tacrolimus suppress the induced production of IP-10 in human keratinocytes.

Expression profiling and functional analysis of Toll-like receptors in primary healthy human nasal epithelial cells shows no correlation and a refractory LPS response.

BackgroundInnate immune recognition via Toll-like receptors (TLRs) on barrier cells like epithelial cells has been shown to influence the regulation of local immune responses. Here we determine expression level variations and functionality of TLRs in nasal epithelial cells from healthy donors.MethodsExpression levels of the different TLRs on primary nasal epithelial cells from healthy donors derived from inferior turbinates was determined by RT-PCR. Functionality of the TLRs was determined by stimulation with the respective ligand and evaluation of released mediators by Luminex ELISA.ResultsPrimary nasal epithelial cells express different levels of TLR1-6 and TLR9. We were unable to detect mRNA of TLR7, TLR8 and TLR10. Stimulation with Poly(I:C) resulted in a significant increased secretion of IL-4, IL-6, RANTES, IP-10, MIP-1β, VEGF, FGF, IL-1RA, IL-2R and G-CSF. Stimulation with PGN only resulted in significant increased production of IL-6, VEGF and IL-1RA. Although the expression of TLR4 and co-stimulatory molecules could be confirmed, primary nasal epithelial cells appeared to be unresponsive to stimulation with LPS. Furthermore, we observed huge individual differences in TLR agonist-induced mediator release, which did not correlate with the respective expression of TLRs.ConclusionOur data suggest that nasal epithelium seems to have developed a delicate system of discrimination and recognition of microbial patterns. Hypo-responsiveness to LPS could provide a mechanism to dampen the inflammatory response in the nasal mucosa in order to avoid a chronic inflammatory response. Individual, differential expression of TLRs on epithelial cells and functionality in terms of released mediators might be a crucial factor in explaining why some people develop allergies to common inhaled antigens, and others do not.

The CXCR3 chemokines in inflammatory myopathies.

The α-chemokines (C-X-C motif) ligand 9 (CXCL9) and interferon γ-induced protein 10 (IP-10) are expressed in idiopathic inflammatory myopathies muscle. Abundant expression of IP-10 was observed on macrophages and T cells surrounding and invading non-necrotic muscle fibers in polymyositis and sporadic inclusion body myositis and in T cells in perimysial infiltrates of dermatomyositis. IP-10 was also localized to blood vessel endothelial cells in all inflammatory and normal muscle tissues. Serum IP-10 is high in patients with inflammatory myopathies. Human skeletal muscle cells might actively self-promote muscular inflammation by eliciting IP-10 secretion, under the influence of cytokines [Interferon (IFN-γ), Tumor Necrosis Factor (TNF-α)], which can amplify T helper (Th)1 cell tissue infiltration in vivo. It has been shown that drugs able to block the IP-10/chemokine (C-X-C motif) receptor 3 (CXCR3) axis can suppress inflammation in muscle.

Monophosphoryl lipid A inhibits the cytokine response of endothelial cells challenged with LPS

Monophosphoryl lipid A (MPLA) is a TLR4 agonist that is used as an immunomodulator in human vaccines; additionally, it has been shown to be protective in models of sepsis. As endothelial cells regulate inflammation, we hypothesized that MPLA would decrease activation of human umbilical vein endothelial cells (HUVECs) to LPS. We studied HUVECs challenged with LPS (100 ng/ml), MPLA (0.001-100 µg/ml) or a combination. Secretion of IL-6, RANTES (CCL5) and IP-10 (CXCL10) were assessed by ELISA. Activation of MAPK phosphorylation and cytokine transcription were assessed by Western blot analysis and PCR, respectively. MPLA alone was a weak stimulator of myeloid differentiation primary response protein 88-dependent IL-6 and did not induce TIR-domain-containing adapter-inducing IFN-β (TRIF)-dependent chemokine responses. MPLA significantly reduced LPS-mediated IL-6 production. This inhibitory effect was also conferred for the TRIF-dependent chemokines RANTES and IP-10. Inhibition of LPS-mediated activation by MPLA was associated with reduced p38 phosphorylation and mRNAs encoding inflammatory cytokines. MPLA inhibition of LPS signaling appeared to be at the level of the TLR4 receptor, acting as a receptor antagonist with weak agonistic properties. This study provides evidence of a novel mechanism for the inhibitory effect of MPLA on LPS-induced endothelial activation.

A new small molecule for treating inflammation and chorioretinal neovascularization in relapsing-remitting and chronic experimental autoimmune uveitis.

We investigated the effect of PP-001, a new small molecule inhibitor of dihydro-orotate dehydrogenase in two experimental rat experimental autoimmune uveitis (EAU) models: a spontaneously relapsing-remitting model and a monophasic/chronic disease model that results in late chorioretinal neovascularization. Both of the diseases are induced by immunization with autoantigen peptides. Prevention was tested using daily oral applications of PP-001 after immunization with the retinal S-antigen peptide PDSAg (for induction of monophasic uveitis and neovascularization) or the interphotoreceptor retinoid-binding protein peptide R14 (for induction of spontaneously relapsing-remitting EAU). Treatment to inhibit relapses and neovascularization was tested using PP-001 daily after the first attack of R14-induced or after onset of PDSAg-induced EAU. Uveitis was graded clinically and histologically. The effect of PP-001 on cytokine secretion and proliferation was evaluated using rat T-cell lines. Preventive feeding of PP-001 abrogated both types of EAU. Starting treatment after the resolution of the first attack led to a significant reduction of the number and intensity of relapses in R14-induced EAU. PP-001-treatment initiated after onset or after peak of PDSAg-induced EAU significantly reduced neovascularization (as determined by histology). Proliferation of antigen-specific T-cell lines and secretion of IFN-γ, IL-17, IL-10, IP-10, and VEGF were efficiently suppressed by PP-001. We investigated a new dihydroorotate dehydrogenase inhibitor as treatment for primary and recurrent disease in relapsing-remitting and chronic rat models of experimental autoimmune uveitis. The small molecule compound PP-001 suppressed proliferation and cytokine secretion of autoreactive T cells (i.e., IFN-g, IL-17, and VEGF) and chorioretinal neovascularization in chronic EAU.

Safety and biocompatibility of carbohydrate-functionalized polyanhydride nanoparticles.

Carbohydrate functionalization of nanoparticles allows for targeting of C-type lectin receptors. This family of pattern recognition receptors expressed on innate immune cells, such as macrophages and dendritic cells, can be used to modulate immune responses. In this work, the in vivo safety profile of carbohydrate-functionalized polyanhydride nanoparticles was analyzed following parenteral and intranasal administration in mice. Polyanhydride nanoparticles based on 1,6-bis-(p-carboxyphenoxy)hexane and 1,8-bis-(p-carboxyphenoxy)-3,6-dioxaoctane were used. Nanoparticle functionalization with di-mannose (specifically carboxymethyl-α-D-mannopyranosyl-(1,2)-D-mannopyranoside), galactose (specifically carboxymethyl-β-galactoside), or glycolic acid induced no adverse effects after administration based on histopathological evaluation of liver, kidneys, and lungs. Regardless of the polymer formulation, there was no evidence of hepatic or renal damage or dysfunction observed in serum or urine samples. The histological profile of cellular infiltration and the cellular distribution and kinetics in the lungs of mice administered with nanoparticle treatments followed similar behavior as that observed in the lungs of animals administered with saline. Cytokine and chemokine profiles in bronchoalveolar lavage fluid indicated surface chemistry dependence on modest secretion of IL-6, IP-10, and MCP-1; however, there was no evidence of any deleterious histopathological changes. Based on these analyses, carbohydrate-functionalized nanoparticles are safe for in vivo applications. These results provide foundational information towards the evaluation of the capabilities of these surface-modified nanoparticles as vaccine delivery formulations.

Tumor-induced senescent T cells promote the secretion of pro-inflammatory cytokines and angiogenic factors by human monocytes/macrophages through a mechanism that involves Tim-3 and CD40L.

Solid tumors are infiltrated by immune cells where macrophages and senescent T cells are highly represented. Within the tumor microenvironment, a cross-talk between the infiltrating cells may occur conditioning the characteristic of the in situ immune response. Our previous work showed that tumors induce senescence of T cells, which are powerful suppressors of lympho-proliferation. In this study, we report that Tumor-Induced Senescent (TIS)-T cells may also modulate monocyte activation. To gain insight into this interaction, CD4+ or CD8+TIS-T or control-T cells were co-incubated with autologous monocytes under inflammatory conditions. After co-culture with CD4+ or CD8+TIS-T cells, CD14+ monocytes/macrophages (Mo/Ma) exhibit a higher expression of CD16+ cells and a reduced expression of CD206. These Mo/Ma produce nitric oxide and reactive oxygen species; however, TIS-T cells do not modify phagocyte capacity of Mo/Ma. TIS-T modulated-Mo/Ma show a higher production of pro-inflammatory cytokines (TNF, IL-1β and IL-6) and angiogenic factors (MMP-9, VEGF-A and IL-8) and a lower IL-10 and IP-10 secretion than monocytes co-cultured with controls. The mediator(s) present in the supernatant of TIS-T cell/monocyte-macrophage co-cultures promote(s) tubulogenesis and tumor-cell survival. Monocyte-modulation induced by TIS-T cells requires cell-to-cell contact. Although CD4+ shows different behavior from CD8+TIS-T cells, blocking mAbs against T-cell immunoglobulin and mucin protein 3 and CD40 ligand reduce pro-inflammatory cytokines and angiogenic factors production, indicating that these molecules are involved in monocyte/macrophage modulation by TIS-T cells. Our results revealed a novel role for TIS-T cells in human monocyte/macrophage modulation, which may have deleterious consequences for tumor progression. This modulation should be considered to best tailor the immunotherapy against cancer.

Gene Expression during the Generation and Activation of Mouse Neutrophils: Implication of Novel Functional and Regulatory Pathways

As part of the Immunological Genome Project (ImmGen), gene expression was determined in unstimulated (circulating) mouse neutrophils and three populations of neutrophils activated in vivo, with comparison among these populations and to other leukocytes. Activation conditions included serum-transfer arthritis (mediated by immune complexes), thioglycollate-induced peritonitis, and uric acid-induced peritonitis. Neutrophils expressed fewer genes than any other leukocyte population studied in ImmGen, and down-regulation of genes related to translation was particularly striking. However, genes with expression relatively specific to neutrophils were also identified, particularly three genes of unknown function: Stfa2l1, Mrgpr2a and Mrgpr2b. Comparison of genes up-regulated in activated neutrophils led to several novel findings: increased expression of genes related to synthesis and use of glutathione and of genes related to uptake and metabolism of modified lipoproteins, particularly in neutrophils elicited by thioglycollate; increased expression of genes for transcription factors in the Nr4a family, only in neutrophils elicited by serum-transfer arthritis; and increased expression of genes important in synthesis of prostaglandins and response to leukotrienes, particularly in neutrophils elicited by uric acid. Up-regulation of genes related to apoptosis, response to microbial products, NFkB family members and their regulators, and MHC class II expression was also seen, in agreement with previous studies. A regulatory model developed from the ImmGen data was used to infer regulatory genes involved in the changes in gene expression during neutrophil activation. Among 64, mostly novel, regulatory genes predicted to influence these changes in gene expression, Irf5 was shown to be important for optimal secretion of IL-10, IP-10, MIP-1α, MIP-1β, and TNF-α by mouse neutrophils in vitro after stimulation through TLR9. This data-set and its analysis using the ImmGen regulatory model provide a basis for additional hypothesis-based research on the importance of changes in gene expression in neutrophils in different conditions.

Comprehensive analysis of inflammatory markers in chronic thromboembolic pulmonary hypertension patients.

Chronic thromboembolic pulmonary hypertension (CTEPH) is associated with chronic inflammation but the pathological mechanisms are largely unknown. Our study aimed to simultaneously profile a broad range of cytokines in the supernatant of pulmonary endarterectomy (PEA) surgical material, as well as prospectively in patients with CTEPH to investigate whether circulating cytokines are associated with haemodynamic and physical characteristics of CTEPH patients. Herein, we show that PEA specimens revealed a significant upregulation of interleukin (IL)-6, monocyte chemoattractant protein-1, interferon-γ-induced protein-10 (IP)-10, macrophage inflammatory protein (MIP)1α and RANTES compared to lung tissue from healthy controls. In prospectively collected serum, levels of IL-6, IL-8, IP-10, monokine induced by interferon-γ (MIG) and MIP1α were significantly elevated in CTEPH patients compared to age- and sex-matched healthy controls. In serum of idiopathic pulmonary arterial hypertension (IPAH) patients, only IP-10 and MIG were significantly increased. In CTEPH but not in IPAH, IP-10 was negatively correlated with cardiac index, 6-min walking distance and carbon monoxide diffusion capacity. In vitro, IP-10 significantly increased migration of freshly isolated adventitial fibroblasts. Our study is the first to show that IP-10 secretion is associated with poor pulmonary haemodynamics and physical capacity in CTEPH and might be involved in the pathological mechanism of PEA tissue formation.

The immunosuppressant Protosappanin A diminished recipient T cell migration into allograft via inhibition of IP-10 in rat heart transplant.

The immunosuppressant Protosappanin A (PrA), isolated from the medicinal herb, promotes cardiac allograft survival, diminishes inflammatory cell infiltration, and inhibits interferon γ-induced protein 10 kDa (IP-10) mRNA expression in rats cardiac grafts. Binding of the chemokine IP-10 to its cognate receptor, CXCR3, plays crucial roles in allograft immunity, especially by mediating the recruitment of effector T cells to allografted tissues. In this study, we attempted to determine whether PrA-mediated inhibition of IP-10 contributes to the effect of reduced T cell infiltration into cardiac allograft within a rat model. Administration of PrA (25 mg/kg daily) via oral gavage following heart transplantation significantly reduced the increase of IP-10 mRNA level in allograft and prevented IP-10 secretion by peripheral blood mononuclear cells (PBMC) isolated from recipient rats seven days posttransplantation. Furthermore, in vitro experiments demonstrated that PrA addition to control PBMC prevented IP-10 secretion. Chemotactic migration assays were utilized to evaluate recipient T cell migration towards PBMC supernatant. PrA administration impaired PBMC supernatant-induced T cell migration. Additional in vitro experiments revealed that PrA slightly reduced naïve T cell migration towards chemokines. The presence of IP-10 in PBMC supernatant prevented PrA from reducing T cell migration in PrA-treated recipients. Neither CXCR3 chemokine ligand Mig nor non-CXCR3 chemokine ligand SDF-1 had any effect on T cell migration in PrA-treated recipients. The addition of anti-CXCR3 antibody restored PrA-mediated inhibition of T cell migration. Immunofluorescence microscopy showed that IP-10 was expressed mainly in CD68 positive infiltrating monocytes. Furthermore, PrA consistently reduced CXCR3+T cell infiltration into cardiac allografts. The reduced intensity of CXCR3 staining in PrA-treated allografts contributed to the previously depressed naïve T cell migrating activity induced by PrA. Collectively, these data indicate that PrA inhibition of IP-10 activity reduced recipient T cell migration and infiltration of cardiac allografts, thus partially explaining the immunosuppressive effect of PrA.

Sjögren's syndrome and chemokines.

Interferon (IFN)-γ-induced protein 10 (IP-10) and its receptor, chemokine (C-X-C motif) receptor (CXCR)3, appear to contribute to the pathogenesis of Sjögren's syndrome (SS). The expression of IP-10 and CXCR3 is increased, in salivary glands from SS patients, both in the ductal epithelium adjacent to lymphoid infiltrates and in lymphocytes. IFN-γ induces the production of high levels of IP-10 and monokine induced by IFN-γ (MIG) proteins from cultured SS salivary epithelial cells. Under the influence of IFN-γ, IP-10 secreted by salivary cells, recruits T helper (Th)1 lymphocytes that may be responsible for enhanced IFN-γ, which in turn stimulates a further IP-10 secretion from epithelial cells creating an amplification feedback loop and perpetuating the autoimmune process. Determination of high level of IP-10 in tears and saliva is therefore a marker of a Th1 orientated immune response. In experimental settings IP-10 antagonists can ameliorate the progression of autoimmune sialadenitis, providing a new therapeutic approach to SS. Further studies are needed to investigate whether IP-10 is a novel therapeutic target in SS in humans.

The alpha chemokine "Interferon gamma-induced protein 10" (IP-10) in Graves' disease

The alpha chemokine Interferon gamma-induced protein 10 (IP-10) and its receptor, CXC receptor 3, appear to contribute to the pathogenesis of Graves' disease (GD) and Graves' ophthalmopathy (GO). Under the influence of Interferon-γ, IP-10 is secreted by thyrocytes (in GD), fibroblasts and preadipocytes (in GO). Determination of high level of IP-10 in peripheral liquids is therefore a marker of a Th1 orientated immune response. Circulating IP-10 is associated with the active phase of GD in both newly diagnosed and relapsing hyperthyroid patients. Methimazole reduces IP-10 secretion by isolated thyrocytes, decreases serum IP-10 levels, and promotes a transition from Th1 to Th2 dominance in patients in GD active phase. In GD patients the decrease of IP-10 after thyroidectomy and radioiodine strongly suggests that this chemokine is mainly produced by the thyroid itself. In GO patients the increased concentrations of IP-10, at least in part, reflect the activity of orbital inflammation. A significant reductions in IP-10 serum concentrations during corticosteroids and or radiotherapy treatments, as compared both to control group and to basal values in GO patients, suggest that this chemokine could serve as a guideline in therapeutic decision-making in patients with GO. Further studies are needed to evaluate whether IP-10 is a novel therapeutic target in GD and GO.

The alpha chemokine "Interferon gamma-induced protein 10" (IP-10) in Graves' disease and Graves'ophthalmopathy

Interferon(IFN)γ-induced protein 10 (IP-10) and its receptor, CXC receptor 3, appear to contribute to the pathogenesis of Graves' disease (GD) and Graves' ophthalmopathy (GO). Under the influence of IFN-γ, IP-10 is secreted by thyrocytes (in GD), fibroblasts and preadipocytes (in GO). Determination of high level of IP-10 in peripheral liquids is therefore a marker of a Th1 orientated immune response. Circulating IP-10 is associated with the active phase of GD in both newly diagnosed and relapsing hyperthyroid patients. Methimazole reduces IP-10 secretion by isolated thyrocytes, decreases serum IP-10 levels, and promotes a transition from Th1 to Th2 dominance in patients with GD active phase. In GD patients the decrease of IP-10 after thyroidectomy and radioiodine strongly suggests that this chemokine is mainly produced by the thyroid itself. In GO patients the increased concentrations of IP-10, at least in part, reflect the activity of orbital inflammation. A significant reductions in IP-10 serum concentrations during corticosteroids and or radiotherapy treatments, as compared both to control group and to basal values in GO patients, suggest that this chemokine could serve as a guideline in therapeutic decision-making in patients with GO. Further studies are needed to evaluate whether IP-10 is a novel therapeutic target in GD and GO.