IP-10 mRNA Expression Research Articles

Contribution of Interferon-β to the Murine Macrophage Response to the Toll-like Receptor 4 Agonist, Lipopolysaccharide

Interferon-beta (IFN-beta) has been identified as the signature cytokine induced via the Toll-like receptor (TLR) 4, "MyD88-independent" signaling pathway in macrophages stimulated by Gram-negative bacterial lipopolysaccharide (LPS). In this study, we analyzed the responses of macrophages derived from wild-type (IFN-beta(+/+)) mice or mice with a targeted mutation in IFN-beta (IFN-beta(-/-)) to the prototype TLR4 agonist, Escherichia coli LPS. A comparison of basal and LPS-induced gene expression (by reverse transcription-PCR, real-time PCR, and Affymetrix microarray analyses) resulted in the identification of four distinct patterns of gene expression affected by IFN-beta deficiency. Analysis of a subset of each group of differentially regulated genes by computer-assisted promoter analysis revealed putative IFN-responsive elements in all genes examined. LPS-induced activation of intracellular signaling molecules, STAT1 Tyr-701, STAT1 Ser-727, and Akt, but not p38, JNK, and ERK MAPK proteins, was significantly diminished in IFN-beta(-/-) versus IFN-beta(+/+) macrophages. "Priming" of IFN-beta(-/-) macrophages with exogenous recombinant IFN-beta significantly increased levels of LPS-induced gene expression for induction of monocyte chemotactic protein 5, inducible nitric-oxide synthase, IP-10, and IL-12 p40 mRNA, whereas no increase or relatively small increases were observed for IL-1beta, IL-6, monocyte chemotactic protein 1, and MyD88 mRNA. Finally, IFN-beta(-/-) mice challenged in vivo with LPS exhibited increased survival when compared with wild-type IFN-beta(+/+) controls, indicating that IFN-beta contributes to LPS-induced lethality; however, not to the extent that one observes in mice with more complete pathway deficiencies (e.g. TLR4(-/-) or TRIF(-/-) mice). Collectively, these findings reveal unanticipated regulatory roles for IFN-beta in response to LPS in vitro and in vivo.

Study on the expression of PBMCs IP-10 mRNA and systemic lupus erythematosus

目的 探讨外周血单个核细胞(PBMCs)干扰素诱导的蛋白10(IP-10)mRNA表达与系统性红斑狼疮(SLE)活动的关系.方法 用逆转录-聚合酶链反应(RT-PCR)检测46例SLE患者、20例类风湿关节炎(RA)患者、11例非SLE肾损伤患者及20名正常健康人PBMCs IP-10 mRNA表达.结果 SLE活动组PBMCs IP-10 mRNA表达水平与非活动组间的差异有统计学意义(P＜0.01),活动性狼疮肾炎(LN)组与无肾损伤组之间PBMCs IP-10 mRNA表达水平的差异亦有统计学意义(P＜0.05),而RA组和非SLE肾病组患者与正常对照组水平相近似(P＞0.05).血清IP-10水平与PBMCs IP-10 mRNA表达高度正相关(r=0.897 1, P＜0.01).PBMCs IP-10 mRNA表达水平与狼疮病活动指数(SLEDAI)评分呈正相关(r=0.683 7,P＜0.01),与肾SLEDAI评分亦高度正相关(r=0.726 0,P＜0.01).结论 SLE活动时期PBMCs IP-10 mRNA表达增加,与SLE疾病活动状况相关,尤其与LN的活动状况密切相关。

Antiangiogenic and Antitumor Activities of IL-27

IL-27 is a novel IL-6/IL-12 family cytokine playing an important role in the early regulation of Th1 responses. We have recently demonstrated that IL-27 has potent antitumor activity, which is mainly mediated through CD8(+) T cells, against highly immunogenic murine colon carcinoma. In this study, we further evaluated the antitumor and antiangiogenic activities of IL-27, using poorly immunogenic murine melanoma B16F10 tumors, which were engineered to overexpress single-chain IL-27 (B16F10 + IL-27). B16F10 + IL-27 cells exerted antitumor activity against not only s.c. tumor but also experimental pulmonary metastasis. Similar antitumor and antimetastatic activities of IL-27 were also observed in IFN-gamma knockout mice. In NOD-SCID mice, these activities were decreased, but were still fairly well-retained, suggesting that different mechanisms other than the immune response are also involved in the exertion of these activities. Immunohistochemical analyses with Abs against vascular endothelial growth factor and CD31 revealed that B16F10 + IL-27 cells markedly suppressed tumor-induced neovascularization in lung metastases. Moreover, B16F10 + IL-27 cells clearly inhibited angiogenesis by dorsal air sac method, and IL-27 exhibited dose-dependent inhibition of angiogenesis on chick embryo chorioallantoic membrane. IL-27 was revealed to directly act on HUVECs and induce production of the antiangiogenic chemokines, IFN-gamma-inducible protein (IP-10) and monokine induced by IFN-gamma. Finally, augmented mRNA expression of IP-10 and monokine induced by IFN-gamma was detected at the s.c. B16F10 + IL-27 tumor site, and antitumor activity of IL-27 was partially inhibited by the administration of anti-IP-10. These results suggest that IL-27 possesses potent antiangiogenic activity, which plays an important role in its antitumor and antimetastatic activities.

Early post-transplant urinary IP-10 expression after kidney transplantation is predictive of short- and long-term graft function

The early identification of renal transplant recipients at enhanced risk of developing acute and subclinical rejection would allow individualized adjustment of immunosuppression before functional graft injury occurs and would exclude these patients from drug-weaning studies. Protein and reverse transcriptase-polymerase chain reaction-based analyses of candidate markers in urine open the opportunity to closely monitor kidney-transplanted patients non-invasively. The chemokine interferon-inducible protein 10 (IP-10; CXCL10) might be an interesting candidate to uncover ongoing immune processes within the graft. Urine samples from kidney-transplanted recipients were retrospectively analyzed for IP-10 mRNA and protein expression. IP-10 levels were correlated with the incidence of acute rejection episodes proven by histology and long-term graft function assessed by the glomerular filtration rate 6 months post transplantation. IP-10 expression in urine identified patients with ongoing acute rejection episodes several days before a biopsy was indicated by rising serum creatinine levels. Most importantly, elevated levels of urinary IP-10 protein within the first four postoperative weeks were predictive of graft function at 6 months even in the absence of acute rejection. These data reveal a correlation between elevated IP-10 expression in urine at early time points post-transplantation and intragraft immune activation that leads to acute rejection and compromised long-term graft function.

Expression of IP-10/CXCL10 Is Upregulated by Double-Stranded RNA in BEAS-2B Bronchial Epithelial Cells

Background: Interferon (IFN)-γ-inducible protein of 10 kDa (IP-10/CXCL10) is a potent chemoattractant for activated T and NK cells, and elevated levels of IP-10 are identified in bronchoalveolar lavage fluids from patients with pulmonary disorders related to Th-1-type immunity, which is a prerequisite for elimination of viral pathogens. Bronchial epithelial cells play an important role in respiratory infections as the initiator of airway inflammation by releasing chemokines and expressing cell surface membrane molecules involved in leukocyte adhesion. Polyinosinic-polycytidylic acid (poly IC) is a synthetic double-stranded RNA (dsRNA) and induces antiviral reactions in cells. Objectives: We investigated the regulation of IP-10 in BEAS-2B bronchial epithelial cells in response to poly IC, and also addressed the possible role of retinoic-acid-inducible gene-I (RIG-I) and IFN-regulatory factor 3 (IRF-3), two genes involved in the signaling induced by viral infection. Methods: The expressions of IP-10 mRNA and protein were analyzed by reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. The overexpression of RIG-I or IRF-3 was performed by transfection of BEAS-2B cells with each cDNA. Results: Poly IC enhanced the expression of IP-10 mRNA and protein in concentration- and time-dependent manners. Overexpression of RIG-I or IRF-3 potentiated the poly-IC-induced upregulation of IP-10. Conclusions: IP-10 may contribute to antiviral activity through the activation of Th-1-type immunity, and RIG-I and IRF-3 may be involved in this reaction.

Anti-IL-23 therapy inhibits multiple inflammatory pathways and ameliorates autoimmune encephalomyelitis

IL-23 is a member of the IL-12 cytokine family that drives a highly pathogenic T cell population involved in the initiation of autoimmune diseases. We have shown that IL-23-dependent, pathogenic T cells produced IL-17 A, IL-17 F, IL-6, and TNF but not IFN-gamma or IL-4. We now show that T-bet and STAT1 transcription factors are not required for the initial production of IL-17. However, optimal IL-17 production in response to IL-23 stimulation appears to require the presence of T-bet. To explore the clinical efficacy of targeting the IL-23 immune pathway, we generated anti-IL-23p19-specific antibodies and tested to determine whether blocking IL-23 function can inhibit EAE, a preclinical animal model of human multiple sclerosis. Anti-IL-23p19 treatment reduced the serum level of IL-17 as well as CNS expression of IFN-gamma, IP-10, IL-17, IL-6, and TNF mRNA. In addition, therapeutic treatment with anti-IL-23p19 during active disease inhibited proteolipid protein (PLP) epitope spreading and prevented subsequent disease relapse. Thus, therapeutic targeting of IL-23 effectively inhibited multiple inflammatory pathways that are critical for driving CNS autoimmune inflammation.

Vascular Endothelial Growth Factor-Induced Signaling Pathways in Endothelial Cells That Mediate Overexpression of the Chemokine IFN-γ-Inducible Protein of 10 kDa In Vitro and In Vivo

Vascular endothelial growth factor (VEGF), an angiogenesis factor, has recently been found to have potent proinflammatory properties in vivo. However, the mechanism by which it mediates inflammation is poorly understood. In this study, we have evaluated the function of VEGF on the induced expression and function of the T cell chemoattractant chemokine IFN-gamma-inducible protein of 10 kDa (IP-10). In vitro, we find that VEGF augments the effect of IFN-gamma on the induction of IP-10 mRNA and protein expression in endothelial cells. Moreover, we show that VEGF and IFN-gamma regulate the activation of the IP-10 promoter, and that the kinases PI3K, phosphoinositide-dependent kinase 1, and Akt act as intermediary signaling molecules for cytokine-inducible IP-10 transcriptional activation in endothelial cells. To examine whether VEGF is functional for IP-10 expression in vivo, Chinese hamster ovary cells that were designed to secrete VEGF were injected s.c. into the skin of nude mice and were found to mediate a time-dependent increase in IP-10 mRNA. This response was reduced in animals treated systemically with the PI3K inhibitor wortmannin. When the Chinese hamster ovary cells expressing VEGF plasmid were injected s.c. into C57BL/6 wild-type or CXCR3-/- mice, they elicited an inflammatory reaction in wild-type but not in CXCR3-/- mice. Collectively, these findings indicate that VEGF-induced augmentation of IP-10 expression is a major mechanism underlying its proinflammatory function.

Inoculation of the cells transfected with IP10 inhibited experimental tumor metastases in vivo

To explore the inhibitory effects of IP10 on the experimental tumor metastases of a mammary carcinoma cell line 4T1 in vivo. 4T1 cells were transfected with pcDNA3-IP10 plasmid and the positive clones (IP10-4T1) were screened in the presence of G418. The parental 4T1 cells and 4T1 cells transfected with pcDNA3 (pcDNA3-4T1) were used as controls. The expression of IP10 mRNA was examined with RT-PCR. The chemotactic activity of the cell-cultured supernatant for the activated lymphocytes was assessed with chemotaxis assay. All BALB/c mice were divided into 3 equal groups: IP10-4T1, parental 4T1 and pcDNA3-4T1 (6 mice in each group). Seven days after mice were inoculated with 2 x 10(6) 4T1, pcDNA3-4T1 or IP10-4T1 cells, 1 x 10(5) 4T1 cells were injected into mice in tail vein. On day 14 tumors were sectioned. On day 28 mice were sacrificed and the lung weight, metastatic forci on the lung surface, disseminated metastases in the lungs and the number of clonogenic metastases of 4T1 cells were observed. The splenocytes were isolated from tumor-bearing mice, and the cytotoxicity of the splenocytes was evaluated by CFSE/7-AAD method. The transcription of IP10 mRNA increased in IP10-4T1 cells compared to parental 4T1 and pcDNA3-4T1 cells (P = 0.002). Moreover, accumulated lymphocytes migrated to the supernatants of IP10-4T1 cells, which can be abrogated by anti-CXCR3 (P < 0.05). Compared to controls, inoculation of IP10-4T1 cells resulted in the decreased disseminated metastases as indicated by dramatically reduced lung metastatic forci on the surface of the lungs; the lung weight was lighter (IP10-4T1, 0.27 +/- 0.02 g v.s. 4T1, 0.48 +/- 0.08 g and pcDNA3-4T1, 0.43 +/- 0.16 g, P = 0.021); the number of clonogenic metastatic 4T1 cells enumerated in ten fields decreased greatly (IP10-4T1, 2.6 +/- 1.7 v.s. 4T1, 34 +/- 6.3 and pcDNA3-4T1, 33 +/- 2.3, P < 0.05); histological assay showed that metastasis was not found in the lungs of the 4/6 of mice in IP10-4T1 group, and was seen in all the mice of parental 4T1 and pcDNA3-4T1 groups. The splenocytes from the mice inoculated with IP10-4T1 cells exhibited stronger cytotoxic activity against 4T1 target cells at different ratios of effector versus target cells (3:1, 9:1, 27:1) than controls (P < 0.05). IP10 expressed locally could inhibit disseminated metastasis of circulating 4T1 tumor cells by enhancing anti-tumor cellular immune responses.

067 Diesel exposure favors Th2 cell recruitment by mononuclear cells from nonatopic subjects by differentially regulating CCL18/PARC and CXCL10/IP-10 production

Allergie asthma is a Th2-mediated inflammatory airway disorder. Its prevalence has strongly increased during the last 20 years, in part related to pollution exposure. Cell recruitment to inflammatory sites is orchestrated by chemokines and their recep-tors such as recruitment of Th2 cells by MDC and 1-309 through CCR4 and CCR8 respectively, or of Thl cells by IP-10 and MIG through CXCR3. Some studies showed that diesel exhaust particles (DEP), especially their associated polyaromatic hydrocarbons (DEP-PAH) can exacerbate the allergie reaction. Much less is known about their potential capacity to induce a Th2-type allergie reaction in non allergie subjects. To address this fundamental question, we investigated the kinetic effect of DEP-PAH on chemokines associated with Thl(IP-10, MIG) and Th2 (MDC, 1-309) recruitment, or induced by Th2 cytokines (PARC). Peripheral blood mononuclear cells (PBMC) from 8 healthy nonatopic subjects were cultured with 25, 50 and 100 ng/ml of DEP-PAH and solvent CH2C12 for 18, 24 and 48 hours. Neu-tralizing anti-IL-4, anti-IL-10 and anti-IL-13 mAbs were used to identify the signaling pathway involved in PARC enhancement. Release of IP-10, MIG, MDC, 1-309, PARC, IL-4, IL-10 and IL-13 was measured by ELISA. mRNA expression of PARC and IP-10 was examined by semiquantitative RT-PCR. Chemotaxis assays were performed on in vitro polarized Th 1 and Th2 cells to evaluate resulting biologie chemotactic activity of supernatants. Diesel exposure did not modify release of MDC, 1-309 and MIG. In contrast, it decreased IP-10 and increased PARC at both protein and mRNA level. The functional effect of chemokine variations resulted in enhanced chemotaxis of Th2 cells but not Thl cells. Th2 cell attraction was inhibited by neutralizing anti-PARC mAb. Neutralizing antibodies against IL-4 and IL-10 had no effect on PARC production while neutralizing anti-IL-13 mAb partly inhibited its release. DEP-PAH could regulate in non atopic subjects chemokines favoring the recruitment of Th2 cells, suggesting that diesel exposure may be involved in the genesis of allergie diseases. Additionally, IL-13 médiates at least one mechanism involved in PARC enhancement by DEP-PAH exposure.

Butyrate blocks interferon-γ-inducible protein-10 release in human intestinal subepithelial myofibroblasts

Interferon (IFN)-gamma-inducible protein (IP)-10 is a chemoattractant for CXCR 3-expressing T lymphocytes and monocytes. IP-10 has been reported to mediate chronic inflammation such as that in inflammatory bowel disease (IBD). However, the local secretion of IP-10 in the intestine remains unclear. In this study, we investigated IP-10 secretion in human colonic subepithelial myofibroblasts (SEMFs). IP-10 secretion was determined by enzyme-linked immunosorbent assay (ELISA), and IP-10 mRNA expression was evaluated by Northern blotting. Interleukin (IL)-10 mRNA was not detected in unstimulated SEMFs. Interferon (IFN)-gamma strongly induced IP-10 mRNA expression. Tumor necrosis factor (TNF)-alpha also stimulated IP-10 mRNA expression, but this was much weaker than that induced by IFN-gamma. The effects of IFN-gamma and TNF-alpha were detected in a dose- and time-dependent manner. These responses were also observed at the protein levels. The IFN-gamma-induced IP-10 secretion was not affected by acetate or propionate, but was significantly reduced by butyrate. Trichostatin A, a specific inhibitor of histone deacetylase, also blocked the IFN-gamma- and TNF-alpha-induced IP-10 mRNA expression, but the effects of trichostatin A were weaker than those of butyrate. The inhibitory effect of butyrate on IFN-gamma-induced IP-10 release was not associated with STAT (signaling transducer and activator of transcription)-1alpha activation. We demonstrated that human colonic SEMFs are the local site for the secretion IP-10. The regulation of IP-10 release by IFN-gamma and butyrate may play an important role in controlling chronic mucosal inflammation in pathological entities such as IBD.

Oral corticosteroids decrease eosinophil and CC chemokine expression but increase neutrophil, IL-8, and IFN-γ–inducible protein 10 expression in asthmatic airway mucosa

Cytokines and chemokines have been implicated in the pathogenesis of asthma. Inhaled corticosteroids have been shown to decrease the number of eosinophils and to downregulate T H 2 cytokines but to increase neutrophils. The effect of corticosteroids on chemokine expression in asthma has not yet been investigated. We sought to investigate the effect of a 2-week course of oral corticosteroid (methylprednisolone, 40 mg/d) on the expression of CXC chemokines (IL-8 and IFN-gamma-inducible protein 10 [IP-10]) and CC chemokines (eotaxin and monocyte chemotactic proteins [MCPs] 1-4) in endoscopic biopsy specimens of 13 patients with moderate-to-severe asthma. CD3, major basic protein, and elastase immunoreactivities were monitored before and after treatment by using immunocytochemistry. Eotaxin, IL-8, IP-10, MCP-1, MCP-2, MCP-3, and MCP-4 mRNA expression in epithelium and submucosa were studied by using in situ hybridization. Corticosteroids reduced the number of CD3-positive T cells and major basic protein-positive eosinophils ( P < .05), whereas the number of neutrophils were increased ( P < .05). Corticosteroids also reduced the number of eotaxin ( P < .05), MCP-3, and MCP-4 mRNA-positive cells ( P < .001) in the epithelium and subepithelium. However, corticosteroids caused a significant increase in the epithelial expression of IL-8 ( P < .001), IP-10 ( P < .05), and MCP-2 mRNAs ( P < .01). Corticosteroids had no effects on MCP-1 mRNA expression. Our results demonstrate the dual nature of corticosteroids. Although corticosteroids can downregulate the expression of some asthma-associated chemokines, such as eotaxin, MCP-3, and MCP-4, they can also upregulate the expression of other chemokines, including IL-8, IP-10, and MCP-2. The failure of oral corticosteroids to inhibit IL-8 mRNA expression might contribute to persistent airway neutrophilia observed in patients with moderate-to-severe asthma, despite treatment with corticosteroids.

Human immunodeficiency virus type 1 Nef protein mediates neural cell death: a neurotoxic role for IP-10

HIV-1 Nef is expressed in astrocytes, but a contribution to neuropathogenesis and the development of HIV-associated dementia (HAD) remains uncertain. To determine the neuropathogenic actions of the HIV-1 Nef protein, the brain-derived (YU-2) and blood-derived (NL4-3) Nef proteins were expressed in neural cells using an alphavirus vector, which resulted in astrocyte death ( P < 0.001). Supernatants from Nef-expressing astrocytes also caused neuronal death, suggesting the release of neurotoxic molecules by astrocytes. Analysis of pro-inflammatory gene induction in astrocytes expressing Nef revealed increased IP-10 mRNA expression (4000-fold) that was Nef sequence dependent. Recombinant IP-10 caused selective cell death in neurons ( P < 0.001) but not astrocytes, and the cytotoxicity of supernatant from astrocytes expressing Nef YU-2 was blocked by an antibody directed against the chemokine receptor CXCR3 ( P < 0.001). SCID/NOD mice implanted with a Nef YU-2-expressing vector displayed abnormal motor behavior ( P < 0.05), neuroinflammation, and neuronal loss relative to controls. Analysis of mRNA levels in brains from patients with HAD also revealed increased expression of IP-10 ( P < 0.05), which was confirmed by immunoreactivity detected principally in astrocytes. Phylogenetic and protein structure analyses of Nef sequences derived from HIV/AIDS patients with and without HAD suggested viral evolution toward a neurotropic Nef protein. These results indicate that HIV-1 Nef contributes to neuropathogenesis by directly causing astrocyte death together with indirect neuronal death through the cytotoxic actions of IP-10 on neurons. Furthermore, Nef molecular diversity was evident in brain tissue among patients with neurological disease and which may influence IP-10 production by astrocytes.

Aerosolized gamma interferon (IFN-gamma) induces expression of the genes encoding the IFN-gamma-inducible 10-kilodalton protein but not inducible nitric oxide synthase in the lung during tuberculosis.

Gamma interferon (IFN-gamma) is critical in the immune response against Mycobacterium tuberculosis. In an ongoing trial of aerosol IFN-gamma in conjunction with standard drug therapy, we have observed activation of IFN signaling in bronchoalveolar lavage (BAL) cells from tuberculosis (TB) patients. We hypothesized that aerosol IFN-gamma treatment of pulmonary TB would increase expression of genes important for the control of TB. We investigated the expression of downstream genes by measuring inducible nitric oxide synthase (iNOS) and the chemokine IFN-inducible 10-kDa protein (IP-10) by real-time quantitative reverse transcription-PCR. In vitro, M. tuberculosis induced IP-10, and IFN-gamma stimulated this further, with no effect on iNOS expression. We studied 21 patients with pulmonary TB and 7 healthy subjects. Similar to the in vitro model, IP-10 mRNA was increased in BAL cells from TB patients and was augmented after treatment with aerosolized IFN-gamma. TB was also associated with elevated iNOS mRNA, but aerosolized IFN-gamma did not further enhance expression. Genomic analysis identified 1,300 of 4,058 genes expressed in BAL cells from six TB patients before and after 1 month of therapy, including aerosolized IFN-gamma. However, only 15 genes were differentially regulated by IFN-gamma. We conclude that iNOS and IP-10 mRNA expression is increased in TB but that aerosol IFN-gamma treatment increases expression of few genes in the human lung.

Neutrophils Sustain Pathogenic CD8 + T Cell Responses in the Heart

This study explores the influence of innate immunity on CD8(+) T-cell responses against heart tissue. Adoptive transfer of ovalbumin-specific CD8(+) effector T cells into CMy-mOva mice, which express ovalbumin in cardiac myocytes, results in a lethal acute myocarditis. The inflammatory infiltrate in the heart includes neutrophils as well as T cells. We used anti-Ly6G antibody to transiently deplete neutrophils at the time of onset of disease. By day 7 after receiving 5 x 10(5) CD8(+) effector T cells, 100% of control Ig-treated CMy-mOva mice had died, while 85% of anti-Ly6G-treated mice survived indefinitely. CD8(+) T-cell infiltration and tissue damage were present in both groups, but the disease was limited in the anti-Ly6G-treated mice, with a rapid disappearance of the adoptively transferred CD8(+) T cells within 11 days. Recovery occurred even though blood neutrophil counts began to rise 48 hours after the last anti-Ly6G treatment. Recovery was associated with a chronic CD4(+) cell infiltrate, and a rapid decline in expression of IFN-gamma and IP-10 mRNA in the myocardium. Neutrophil depletion did not effect survival of CMy-mOva mice that received 3 x 10(6) CD8(+) T cells. These data show that granulocytic inflammation sustains CD8(+) T-cell-mediated heart disease, which has important implications for the pathogenesis and treatment of acute myocarditis and allograft rejection.

High Expression of p40tax and Pro-inflammatory Cytokines and Chemokines in the Lungs of Human T-Lymphotropic Virus Type 1-Related Bronchopulmonary Disorders

Human T-lymphotropic virus type 1 (HTLV-1) is closely associated with the development of certain pulmonary diseases, such as bronchiolitis, although the pathologic mechanism remains unclear. To elucidate the pathogenesis of HTLV-1-associated bronchopulmonary disorders, we analyzed the relationship between expression of p40(tax), a regulatory component of HTLV-1 that stimulates various host genes, and synthesis of pro-inflammatory cytokines and chemokines by cells in BAL fluid (BALF) obtained from HTLV-1-infected patients. Reverse transcription-polymerase chain reaction was used to compare the expression of p40(tax) and pro-inflammatory cytokines and chemokines messenger RNA (mRNA) in BALF of 10 HTLV-1 carriers and 7 healthy subjects. We also studied the correlation between these parameters and the proportion of lymphocytes in BALF. The expression levels of pro-inflammatory cytokines (interferon [IFN]-gamma, interleukin-2) and chemokines (monocyte chemotactic protein-1, macrophage inflammatory protein [MIP]-1alpha, IFN-gamma-inducible protein-10 [IP-10]) were significantly higher in BALF of patients than of healthy subjects. The expression of IFN-gamma and MIP-1alpha mRNA correlated with that of p40(tax). IFN-gamma and IP-10 mRNA expression correlated with the proportion of lymphocytes in BALF. The percentage of lymphocytes in BALF increased with higher expression levels of p40(tax) mRNA, although the correlation was not significant. Our results suggested that p40(tax) seems be involved in the development of HTLV-1-associated bronchopulmonary disorders at least in part through the local production of pro-inflammatory cytokines and chemokines.

Marked Up-regulation of T Lymphocytes and Expression of Interleukin-9 in Bronchial Biopsies From Patients With Chronic Bronchitis With Obstruction

To examine the differences in the inflammatory cell and cytokine profile between patients with chronic bronchitis (CB) with and without airway obstruction compared to control subjects. We used bronchial biopsy samples from the patients and control subjects and analyzed them for the presence of CD3 T cells, CD68, major basic protein (MBP), elastase, and tryptase, as well as expression of messenger RNA (mRNA) coding for interleukin (IL)-4, IL-5, interferon (IFN)-gamma, IL-9, eotaxin, and IFN-gamma-inducible protein (IP)-10. The techniques of immunocytochemistry and in situ hybridization were used. Results were expressed as the number of immunoreactive and mRNA-positive cells per field. Increased number of elastase, CD68, and MBP-positive cells (n = 9, p < 0.01) was demonstrated in both groups of patients with CB compared to control subjects. In patients with CB and obstruction, the number of elastase, CD68, and the number of CD3-positive cells was significantly increased compared to patients with CB without obstruction (n = 9, p < 0.01). IFN-gamma mRNA expression was increased in both groups of patients with CB compared to control subjects (n = 9, p < 0.01). IL-9 mRNA was significantly increased only in patients with CB and obstruction (n = 9, p < 0.01). Co-localization studies demonstrated > 80% of all IL-9-positive cells to be CD3-positive T cells. IP-10 mRNA was significantly increased in both groups of patients with CB compared to control subjects (n = 9, p < 0.01). These results indicate a differential expression of inflammatory markers and cytokine mRNA in patients with obstructive CB. Increased presence of T lymphocytes and up-regulation of IL-9 and IP-10 mRNA expression in the bronchial biopsy samples may contribute to the airway obstruction in these patients.

Upregulation of chemokine expression in the retinal vasculature in ischemia-reperfusion injury.

To evaluate chemokine expression at various retinal sites after ischemia-reperfusion injury, using reverse transcription-polymerase chain reaction (RT-PCR) analysis of selected tissue obtained by laser capture microdissection. Retinal ischemia was produced in Lewis rats by increasing intraocular pressure for 75 minutes. At 3, 6, 12, and 24 hours after reperfusion, RT-PCR was used to measure the levels of monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, interleukin (IL)-8, and interferon-gamma-inducible 10-kDa protein (IP-10) mRNA expression in the ganglion cell layer (GCL), inner nuclear layer (INL), outer nuclear layer (ONL), and retinal vessels, after laser capture microdissection of these retinal layers. These chemokines were further localized by immunohistochemical methods, using antibodies specific to MCP-1 and MIP-1alpha. Leukocyte infiltration into the retina was detected with immunostaining for leukocyte common antigen. Ischemia-reperfusion induced expression of MCP-1, MIP-1alpha, and MIP-1beta mRNA in the retinal vessels 3 hours after reperfusion. Six hours after reperfusion, expression of these chemokines and IL-8 mRNA was seen in the GCL and INL. Twelve hours after reperfusion, IP-10 mRNA expression was seen in the GCL and INL. Immunoreactive MCP-1 and MIP-1alpha were detected in the GCL, INL, and the retinal vessels 24 hours after reperfusion. No chemokine mRNA expression or immunoreactivity was detected in the ONL at any time. Leukocyte infiltration was noted at 12 hours, increasing markedly 24 hours after reperfusion. Ischemia-reperfusion retinal injury results in generation of highly chemotactic agents, initially in the retinal vasculature, then in the other inner retinal layers. Such differential chemokine expression may play a role in leukocyte recruitment and selective leukocyte infiltration in the inner retina, leading to retinal damage primarily localized to the ganglion cells and other inner neuronal structures.

Regulation of Blastocyst Migration, Apposition, and Initial Adhesion by a Chemokine, Interferon γ-inducible Protein 10 kDa (IP-10), during Early Gestation

For a pregnancy to be established, initial apposition and adhesion of the blastocyst to maternal endometrium must occur in a coordinated manner; however, a key factor(s) that mediates the trophoblast cell migration and attachment to the apical surface of the endometrium has not been identified. In this study, we examined the effect of an endometrial chemokine, interferon-gamma-inducible protein 10 kDa (IP-10), on conceptus migration to the endometrial epithelium. We first studied endometrial IP-10 mRNA expression, which was localized in the subepithelial stromal region, and detected the protein in the uterine flushing media during early pregnancy. Expression of IP-10 mRNA by the endometrium of cyclic animals was stimulated by the addition of a conceptus factor interferon-tau (IFN-tau). Immunofluorescent analysis revealed that IP-10 receptor, CXCR3, was localized in the trophoblast cells, to which biotinylated-recombinant caprine IP-10 (rcIP-10) bound. Chemotaxis assay indicated that rcIP-10 stimulated the migration of trophoblast cells, and the effects of rcIP-10 were neutralized by the pretreatment with an anti-IP-10 antibody. Adhesive activity of trophoblast cells to fibronectin was promoted by rcIP-10, and the effect was inhibited by the use of anti-IP-10 antibody. Further adhesion experiments demonstrated that binding of trophoblast cells to fibronectin was completely inhibited by a peptide of the Arg-Gly-Asp (RGD) sequence, which binds to integrins alpha5beta1, alphaVbeta1, alphaVbeta3, and alphaVbeta5, whereas non-binding peptide containing Arg-Gly-Glu (RGE) had minimal effects. More importantly, rcIP-10 promoted the adhesion of trophoblast cells to primary cells isolated from endometrial epithelium. Furthermore, rcIP-10 stimulated the expression of integrin alpha5, alphaV, and beta3 subunit mRNA in trophoblast cells. These findings suggest that endometrial IP-10 regulates the establishment of apical interactions between trophoblast and epithelial cells during early gestation.

Expression of IFN-γ-inducible chemokines in inclusion body myositis

Because IFN-γ-inducible chemokines, Mig (CXCL9), IP-10 (CXCL10), I-TAC (CXCL11) and their receptor, CXCR3, are critical molecules in T cell trafficking and generation of effector T cells, we examined their expression in the muscle biopsies of patients with sporadic inclusion body myositis (s-IBM) and disease controls. The functional role of these molecules was also studied by examining the effect and time kinetics of IFN-γ in inducing Mig and IP-10 expression in human myotubes in vitro. We found significantly high levels of Mig and IP-10 mRNA expression in s-IBM muscles compared to controls. IFN-γ upregulated the mRNA expression of Mig and IP-10 by human myotubes in a dose-dependent manner. By double-label immunohistochemistry, Mig was expressed on a subset of CD8 + cells and the areas of the muscle fiber in contact or contiguous to the T cells; CXCR3 was expressed only on a subset of the autoinvasive CD8 + T cells but not the myofibers. IP-10 and I-TAC were not detected by immunocytochemistry. The findings indicate that in s-IBM, IFN-γ is involved in the upregulation and in situ production of proinflammatory chemokines, which, in turn, participate in the recruitment of activated T cells and contribute to the self-sustaining nature of endomysial inflammation.

Expression of the chemokine IP-10 correlates with the accumulation of hepatic IFN-gamma and IL-18 mRNA in chronic hepatitis C but not in hepatitis B.

The pathogenesis of hepatitis C virus-induced chronic liver disease is still poorly understood. Previous studies revealed enhanced hepatic expression of the Th1 prototype cytokine IFN-gamma in individuals with chronic hepatitis C. In accordance with several animal models of experimentally induced hepatitis, a Th1 lymphocyte driven inflammatory process, which involves newly infiltrated as well as resident monocytes/macrophages, has been proposed. An involvement of the interferon-gamma-inducible chemokine IP-10, which is chemoattractive for stimulated Th1 cells and monocytes, is also suggested. Using an HBV transgenic mouse model, a reduction of hepatic infiltration and liver disease was achieved recently by administration of antibodies directed against the interferon-gamma-inducible chemokine Mig and against IP-10. In the present study, expression of IP-10 was investigated both in serum and in the liver of patients with chronic hepatitis C and hepatitis B. Patients with liver diseases of non-viral etiologies served as controls. IP-10 expression was highest in hepatitis C. In chronic hepatitis C, but not in chronic hepatitis B nor in liver disorders unrelated to viral infections, IP-10 expression was strongly correlated with the amount of transcripts for IFN-gamma and to the amount of transcripts for the constitutively expressed macrophage derived cytokine IL-18. Hepatic inflammatory activity, however, was found to be associated more closely with IFN-gamma than with IP-10 or IL-18 mRNA expression. The data support the hypothesis that IP-10 is responsible for the recruitment of Th cells and monocytes in chronic hepatitis C, and suggest that its role in chronic hepatitis B is less determining. Moreover, they deliver additional support for the view that IFN-gamma still has to be considered as a mediator that determines the outcome of inflammation, e.g., via its ability to activate IL-18 expressing cells and to initiate a delayed type hypersensitivity reaction.