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Sample records for 3-methylcholanthrene increases ifn

  1. Effect of 3-methylcholanthrene-induced increases in ascorbic acid levels on tissue. beta. -glucuronidase activity in rats

    SciTech Connect

    Calabrese, E.J.; Barrett, T.J.; Leonard, D.A.; Horton, H.M.; Kenyon, E.M.

    1988-01-01

    The interrelationship between tissue ascorbic acid levels and tissue ..beta..-glucuronidase activity was examined in rats injected with 3-methylcholanthrene, an agent which induces ascorbic acid synthesis in rats. Six Fisher 344 rats were dosed intraperitoneally (IP) with 30 mg/kg of 3-methylcholanthrene. Ascorbic acid levels and ..beta..-glucuronidase (..beta..-G) activity were determined for lung, liver and kidney tissues. In a follow-up study, rats were dosed for three consecutive days with 3-methylcholanthrene. Controls in both groups were dosed IP with Emulphor (EL-620). Animals were sacrificed one week after the final dosage and lung, liver and kidney tissues were examined.

  2. Activation of liver X receptor inhibits the development of pulmonary carcinomas induced by 3-methylcholanthrene and butylated hydroxytoluene in BALB/c mice.

    PubMed

    Wang, Qixue; Sun, Lei; Yang, Xiaoxiao; Ma, Xingzhe; Li, Qi; Chen, Yuanli; Liu, Ying; Zhang, Di; Li, Xiaoju; Xiang, Rong; Wei, Yuquan; Han, Jihong; Duan, Yajun

    2016-01-01

    We previously reported that LXR ligand, T0901317, inhibited the growth of inoculated Lewis lung carcinoma in C57BL/6 mice by activating IFN-γ production. However, the effects of T0901317 on carcinogen-induced pulmonary carcinomas remain unknown. In this study, we initially conducted a statistical analysis on the data of human lung cancer samples extracted from the TCGA database, and determined that survival rate/time of lung cancer patients and grade of lung adenocarcinoma were positively and negatively related to lung IFN-γ levels, respectively. We then determined the inhibitory effects of T0901317 on mouse pulmonary carcinomas induced by 3-methylcholanthrene (MCA) and butylated hydroxytoluene (BHT) or urethane. We found that T0901317 reduced morbidity and mortality in MCA/BHT-injected BALB/c mice by inhibiting lung adenocarcinoma. T0901317 also protected C57BL/6 mice, but not IFN-γ deficient (IFN-γ(-/-), C57BL/6 background) mice, against MCA/BHT-induced lung hyperplasia/inflammation. In addition, we determined that T0901317 inhibited urethane-induced lung tumors in BABL/c mice. Furthermore, we determined that T0901317 prevented metastasis of 4T1 breast cancer cells in BALB/c mice. Administration of T0901317 substantially increased serum IFN-γ levels and lung IFN-γ expression in BABL/c and C57BL/6 mice. Taken together, our study demonstrates that LXR inhibits MCA/BHT-induced pulmonary carcinomas in BABL/c mice and the inhibition is associated with induction of IFN-γ production. PMID:27250582

  3. Activation of liver X receptor inhibits the development of pulmonary carcinomas induced by 3-methylcholanthrene and butylated hydroxytoluene in BALB/c mice

    PubMed Central

    Wang, Qixue; Sun, Lei; Yang, Xiaoxiao; Ma, Xingzhe; Li, Qi; Chen, Yuanli; Liu, Ying; Zhang, Di; Li, Xiaoju; Xiang, Rong; Wei, Yuquan; Han, Jihong; Duan, Yajun

    2016-01-01

    We previously reported that LXR ligand, T0901317, inhibited the growth of inoculated Lewis lung carcinoma in C57BL/6 mice by activating IFN-γ production. However, the effects of T0901317 on carcinogen-induced pulmonary carcinomas remain unknown. In this study, we initially conducted a statistical analysis on the data of human lung cancer samples extracted from the TCGA database, and determined that survival rate/time of lung cancer patients and grade of lung adenocarcinoma were positively and negatively related to lung IFN-γ levels, respectively. We then determined the inhibitory effects of T0901317 on mouse pulmonary carcinomas induced by 3-methylcholanthrene (MCA) and butylated hydroxytoluene (BHT) or urethane. We found that T0901317 reduced morbidity and mortality in MCA/BHT-injected BALB/c mice by inhibiting lung adenocarcinoma. T0901317 also protected C57BL/6 mice, but not IFN-γ deficient (IFN-γ−/−, C57BL/6 background) mice, against MCA/BHT-induced lung hyperplasia/inflammation. In addition, we determined that T0901317 inhibited urethane-induced lung tumors in BABL/c mice. Furthermore, we determined that T0901317 prevented metastasis of 4T1 breast cancer cells in BALB/c mice. Administration of T0901317 substantially increased serum IFN-γ levels and lung IFN-γ expression in BABL/c and C57BL/6 mice. Taken together, our study demonstrates that LXR inhibits MCA/BHT-induced pulmonary carcinomas in BABL/c mice and the inhibition is associated with induction of IFN-γ production. PMID:27250582

  4. Hyper- and Hypo- Induction of Cytochrome P450 activities with Aroclor 1254 and 3-Methylcholanthrene in Cyp1a2(−/−) mice

    PubMed Central

    Barker, Melissa L.; Hathaway, Laura B.; Arch, Dorinda D.; Westbroek, Mark L.; Kushner, James P.; Phillips, John D.; Franklin, Michael R.

    2009-01-01

    The response of hepatic mono-oxygenase activities to Aroclor 1254 or 3-methylcholanthrene was investigated in wild-type and Cyp1a2(−/−) mice. Cytochrome P450 concentrations were similar in naïve Cyp1a2(−/−) and wild-type mice. There was no difference between naïve wild-type and Cyp1a2(−/−) animals in 7-ethoxyresorufin and 7-ethoxy-4-trifluoromethylcoumarin dealkylase activities, nor was the induction response after 3-methylcholanthrene any different between the two genotypes. However, both activities were induced to a higher extent in Cyp1a2(−/−) mice after Aroclor 1254. In contrast, 7-pentoxyresorufin dealkylation activity was lower in Cyp1a2(−/−) mice and this differential was maintained during induction by both agents. 7-Methoxy- and 7-benzoxyresorufin dealkylation activities were also lower than wild-type in naïve Cyp1a2(−/−) animals and during 3-methylcholanthrene induction, but showed accelerated induction in Cyp1a2(−/−) mice with Aroclor 1254. Bufuralol 1′- and testosterone 6β-hydroxylation activities, and P450 characteristics were evaluated 48 hours after inducer administration. Bufuralol 1′-hydroxylation, a sexual dimorphic activity (female > male) showed no genotype differences in naïve animals. Activity changes varied across gender and genotype, with 3-methylcholanthrene and Aroclor 1254 inducing in male Cyp1a2(−/−), and Aroclor 1254 inducing in female wild-type. Testosterone 6β-hydroxylation activity was 16% higher in Cyp1a2(−/−) mice and neither 3-methylcholanthrene nor Aroclor 1254 elicited induction. After Aroclor 1254, a 24% increase in P450 concentration with a hypsochromic shift in the ferrous-CO maximum characteristic of CYP1A enzymes occurred in wild-type, compared to no change in either parameter in Cyp1a2(−/−) mice. Induction changes with 3-methylcholanthrene were greater in wild-type mice, a 60% increase in concentration and ~2 nm hypsochromic shift versus a 10% increase and ~1 nm hypsochromic

  5. Inducible Monooxygenase Activities and 3-Methylcholanthrene-Initiated Tumorigenesis in Mouse Recombinant Inbred Sublines

    PubMed Central

    Atlas, Steven A.; Taylor, Benjamin A.; Diwan, Bhalchandra A.; Nebert, Daniel W.

    1976-01-01

    The induction of a certain group of hepatic monooxygenase activities by polycyclic aromatic compounds is regulated by the same locus or gene cluster controlling the formation of cytochrome P1–450 (P–448) in mice. Certain inbred strains of mice are "responsive" (Ahb) to such induction, whereas others are "nonresponsive" (Ahd). A pair of closely related sublines that differ with respect to the Ah locus (for aromatic hydrocarbon responsiveness) were used to identify or confirm the pleiotropic effects of this gene. The lines were derived by sibling-mating without selection from (C57L/J x AKR/J)F 2 mice; the two sublines were separated at the F12 generation. Ten microsomal monooxygenase activities and one cytosol enzyme activity known to be associated with the Ah locus were similarly associated with cytochrome P1–450 formation in these recombinant inbred sublines as well. Nine additional hepatic monooxygenase activities studied were found not to be associated with the Ah locus; certain of these activities were increased slightly, following treatment of nonresponsive as well as responsive mice with polycyclic aromatic compounds. The Ahb-containing subline was highly susceptible to 3-methylcholanthrene-induced subcutaneous sarcomas, whereas the Ah-d-containing subline was relatively resistant. These results emphasize the potential importance of this particular enzyme for the study of coordinated regulation in mammals. PMID:955403

  6. In vivo effects of 3-methylcholanthrene, phenobarbital, pyrethrum and 2,4,5-T isooctylester on liver, lung and kidney microsomal mixed-function oxidase system of guinea-pig: a comparative study.

    PubMed

    Işcan, M; Arinç, E; Vural, N; Işcan, M Y

    1984-01-01

    The optimum conditions (pH, microsomal protein amount and substrate concentration) of guinea-pig liver, lung and kidney microsomal aniline 4-hydroxylase, ethylmorphine N-demethylase and benzo[a]pyrene hydroxylase activities were determined. Male guinea-pigs weighing 500-700 g were administered 3-methylcholanthrene (25 mg/kg, i.p. 3 days), phenobarbital (75 mg/kg, i.p. 3 days), pyrethrum (120 mg/kg, i.p. 2 days) and 2,4,5-T isooctylester (200 mg/kg, i.p. 3 days). 3-Methylcholanthrene treatment caused significant increases in liver microsomal benzo[a]pyrene hydroxylase and kidney microsomal aniline 4-hydroxylase activities. However, with phenobarbital treatment the only significant increase was observed in liver microsomal ethylmorphine N-demethylase activity. Pyrethrum treatment decreased kidney microsomal ethylmorphine N-demethylase activity significantly. 2,4,5-T isooctylester treatment increased liver microsomal aniline 4-hydroxylase and lung microsomal ethylmorphine N-demethylase activities significantly. Liver microsomal NADPH-cytochrome c reductase activity was increased significantly by phenobarbital and pyrethrum treatment. The other treatments did not cause any significant changes in microsomal NADPH-cytochrome c reductase activities of liver, lung and kidney. Cytochrome P-450 content of guinea-pig liver microsomes were increased significantly about 2.5-fold and 2-fold by treatment with 3-methylcholanthrene and phenobarbital, respectively. 3-Methylcholanthrene also caused 1 nm spectral shift in the absorption maxima of CO difference spectrum of the dithionite-reduced liver microsomal cytochrome P-450, forming P-449. PMID:6141874

  7. Regulation of nonmuscle myosin II during 3-methylcholanthrene induced dedifferentiation of C2C12 myotubes

    SciTech Connect

    Dey, Sumit K.; Saha, Shekhar; Das, Provas; Das, Mahua R.; Jana, Siddhartha S.

    2014-08-01

    3-Methylcholanthrene (3MC) induces tumor formation at the site of injection in the hind leg of mice within 110 days. Recent reports reveal that the transformation of normal muscle cells to atypical cells is one of the causes for tumor formation, however the molecular mechanism behind this process is not well understood. Here, we show in an in vitro study that 3MC induces fragmentation of multinucleate myotubes into viable mononucleates. These mononucleates form colonies when they are seeded into soft agar, indicative of cellular transformation. Immunoblot analysis reveals that phosphorylation of myosin regulatory light chain (RLC{sub 20}) is 5.6±0.5 fold reduced in 3MC treated myotubes in comparison to vehicle treated myotubes during the fragmentation of myotubes. In contrast, levels of myogenic factors such as MyoD, Myogenin and cell cycle regulators such as Cyclin D, Cyclin E1 remain unchanged as assessed by real-time PCR array and reverse transcriptase PCR analysis, respectively. Interestingly, addition of the myosin light chain kinase inhibitor, ML-7, enhances the fragmentation, whereas phosphatase inhibitor perturbs the 3MC induced fragmentation of myotubes. These results suggest that decrease in RLC{sub 20} phosphorylation may be associated with the fragmentation step of dedifferentiation. - Highlights: • 3-Methylcholanthrene induces fragmentation of C2C12-myotubes. • Dedifferentiation can be divided into two steps – fragmentation and proliferation. • Fragmentation is associated with rearrangement of nonmuscle myosin II. • Genes associated with differentiation and proliferation are not altered during fragmentation. • Phosphorylation of myosin regulatory light chain is reduced during fragmentation.

  8. STRAIN-SPECIFIC SENSITIVITY TO INDUCTION OF MURINE LUNG TUMORS FOLLOWING IN UTERO EXPOSURE TO 3-METHYLCHOLANTHRENE

    EPA Science Inventory

    We previously demonstrated that different strains of fetal mice were more sensitive to lung tumor induction by 3-methylcholanthrene (MC) than were adults. Offspring from either a D2 x B6D2F1 backcross or from parental Balb/c mice exhibited a similar high incidence of lung tumors ...

  9. STRAIN-DEPENDENT SUSCEPTIBILITY TO TRANSPLACENTALLY-INDUCED MURINE LUNG TUMORS AND DNA ADDUCTS OF 3-METHYLCHOLANTHRENE

    EPA Science Inventory

    Strain-dependent susceptibility to transplacentally-induced murine lung tumors and DNA adducts of 3methylcholanthrene G B Nelson, J A Ross, J E Moore, M Xu, N D Kock, M S Miller Wake Forest University, Winston-Salem, NC and USEPA, Research Triangle Park, NC.

    It has been de...

  10. Consequences of 3-methylcholanthrene-type induction for the metabolism of 4-aminobiphenyl in isolated rat hepatocytes.

    PubMed

    Orzechowski, A; Schrenk, D; Schut, H A; Bock, K W

    1994-03-01

    Carcinogenic aromatic amines such as 4-aminobiphenyl (4-ABP) are extensively metabolized by both oxidative and conjugation reactions. Thus the burden of genotoxic metabolites of 4-ABP in a target organ is probably influenced by the balance of N-hydroxylation and alternative metabolic pathways in the hepatocyte. In freshly isolated rat hepatocytes, 4-ABP (at a substrate concentration of 10 microM) was mainly N-acetylated (54% of total metabolites), while 2% N-hydroxy-4-ABP-N-glucuronide and 21% of unconjugated N-hydroxylated metabolites were detectable. Ring-hydroxylated metabolites and the primary N-glucuronide of 4-ABP accounted for 8% and 4%, respectively. Pretreatment of rats with 3-methylcholanthrene (MC), a dioxin-type inducer of CYP1A isozymes and phenol UDP-glucuronosyltransferase (UGT1A1), led to a dramatic decrease of N-acetylated (2% of total metabolites) and an increase of N-hydroxylated (54% as free and glucuronidated compound) and ring-hydroxylated (35%) metabolites. Essentially similar effects were seen at a substrate concentration of 50 microM. Consistently, MC-type induction with beta-naphthoflavone resulted in a significant increase in the formation of DNA adducts of 4-ABP, detected by 32P-postlabeling of hepatocellular DNA. The results suggest that, similar to a previous study with 2-naphthylamine (2-NA), MC treatment leads to a marked shift from conjugation to N-oxidation. However, N-hydroxy-4-ABP (in contrast to N-hydroxy-2-NA) is mostly released from hepatocytes in the unconjugated form. PMID:8118934

  11. Downregulation of Mouse Hepatic CYP3A Protein by 3-Methylcholanthrene Does Not Require Cytochrome P450-Dependent Metabolism

    PubMed Central

    Lee, Chunja; Ding, Xinxin

    2013-01-01

    The aryl hydrocarbon receptor (AHR)–dependent induction of cytochromes P450 (P450) such as CYP1A1 by 3-methylcholanthrene (MC) and related polycyclic aromatic hydrocarbons is well characterized. We reported previously that MC treatment triggers a pronounced downregulation, particularly at the protein level, of mouse hepatic Cyp3a11, a counterpart of the key human drug-metabolizing enzyme CYP3A4. To determine whether this effect of MC requires hepatic microsomal P450 activity, we studied liver Cpr-null (LCN) mice with hepatocyte-specific conditional deletion of the NADPH-cytochrome P450 oxidoreductase gene. In vehicle-treated animals, basal levels of CYP3A11 mRNA and CYP3A protein immunoreactivity were elevated by approximately 9-fold in LCN mice compared with wild-type (WT) mice, whereas CYP3A catalytic activity was profoundly compromised in LCN mice. MC treatment caused suppression of CYP3A11 mRNA, CYP3A protein immunoreactivity, and CYP3A catalytic activity in WT mice, and the MC effects at the mRNA and protein levels were maintained in LCN mice. Flavin-containing monooxygenase-3 (Fmo3) induction by MC was suggested previously to occur via an AHR-dependent mechanism requiring conversion of the parent compound to DNA-damaging reactive metabolites; however, hepatic FMO3 mRNA levels were dramatically increased by MC in both WT and LCN mice. MC did not function as a mechanism-based inactivator of CYP3A enzymes in hepatic microsomes prepared from untreated WT mice, under conditions in which 1-aminobenzotriazole caused marked NADPH-dependent loss of total P450 content and CYP3A catalytic activity. These results indicate that MC downregulates mouse hepatic CYP3A protein via a pretranslational mechanism that does not require hepatic microsomal P450-dependent activity. PMID:23846873

  12. Increased per cell IFN-γ productivity indicates recent in vivo activation of T cells

    PubMed Central

    Schlingmann, Tobias R.; Shive, Carey L.; Targoni, Oleg S.; Tary-Lehmann, Magdalena; Lehmann, Paul V.

    2009-01-01

    Immunization with vaccinia virus causes long-term immunity. Efforts have been made to characterize the T cells responsible for this protection. Recently, T cell subsets were described that not only co-express multiple cytokines, but also show increased per cell cytokine productivity. These highly productive cells are often considered to be the most protective. We used ELISPOT assays to measure per cell IFN-γ productivity of vaccinia specific T cells in childhood immunized adults immediately before and at different time points after vaccinia re-vaccination. Apart from an increase in frequency, we found a marked increase of IFN-γ productivity following vaccinia re-vaccination. However, these changes were short-lived as both parameters quickly returned to baseline values within 22 days after re-vaccination. Therefore, increased per cell IFN-γ productivity seems to be a sign of recent in vivo T cell activation rather than a stable marker of a distinct T cell subset responsible for long-term immune protection. PMID:19427634

  13. Induction of hepatic cytochrome P-450 activity in wild cotton rats (Sigmodon hispidus) by phenobarbital and 3-methylcholanthrene

    SciTech Connect

    Elangbam, C.S.; Qualls, C.W.,Jr.; Bauduy, M. )

    1989-05-01

    Wild cotton rats (Sigmodon hispidus) are ubiquitous throughout the Southeast quadrant of the United States, easy to capture, have a generation interval of less than one year and a limited range of movement (less than one hectare). This species may prove to be an excellent model for monitoring environmental contamination. Traditionally, cytochrome P-450 inducing agents are grouped into two classes. One, represented by phenobarbital, induces P-450b and P-450e; the other, represented by 3-methylcholanthrene, induces P-450c and P-450d isoenzymes. The types and amounts of cytochrome P-450 vary among species, organs, health status, sex, and stress of the animal. If the levels of cytochrome P-450 of wild cotton rats are to be used in monitoring environmental pollution, it is necessary to characterize the inducibility and concentration of cytochrome P-450 in this species. This study was designed to determine the concentration and inducibility of cytochrome P-450 in the livers of cotton rats after intraperitoneal (ip) administration of phenobarbital and 3-methylcholanthrene.

  14. Hepatic mixed function oxidase system and effect of phenobarbital, 3-methylcholanthrene and 1, 1, 1-trichloro-2, 2-bis(p-chlorophenyl)ethane in developing chickens.

    PubMed

    Hatolkar, V S; Pawar, S S

    1992-05-01

    Contents of hepatic microsomal protein, aminopyrine N-demethylase, acetanilide hydroxylase, aniline hydroxylase, hydrogen peroxide formation, cytochrome-c-reductase, cytochrome b5 and cytochrome P-450 were examined in control, phenobarbital (PB), 3-methylcholanthrene (3-MC) and 1, 1, 1-trichloro-2, 2-bis(p-chlorophenyl)ethane (DDT) treated group of 1-28 days old chickens. Increase in aminopyrine N-demethylase, acetanilide hydroxylase, aniline hydroxylase, cytochrome-c-reductase, cytochrome b5 and cytochrome P-450 was noticed at all stages of development during administration of PB and 3-MC. But these enzyme activities were not always paralleled by increase in age. Aminopyrine N-demethylase was increased in early stages only during DDT administration, which indicates that the form of cytochrome P-450, responsible for aminopyrine N-demethylation is present in early stages only. However, acetanilide hydroxylase was decreased in all stages of development, in postnatal development the basal activities of the enzymes for various substrates do not exhibit identical pattern, the degree of inducibility by inducers varied in relation to age of animal. Hydrogen peroxide formation increased in all stages of developing chickens due to the administration of PB and DDT. It however decreased due to 3-MC administration which may be due to induction of high spin cytochrome P-450. PMID:1459619

  15. Modulation of 3-methylcholanthrene toxicity in cultured neoplastic keratinocytes by glucocorticoids and retinoids is not accounted for by macromolecular adduct formation

    SciTech Connect

    Rubin, A.L.; Rice, R.H. )

    1989-04-01

    3-Methylcholanthrene (3-MC) greatly inhibits the growth of two lines of human squamous carcinoma cells, SCC-9 and SCC-12B{sub 2}. The degree of 3-MC-mediated inhibition, however, was markedly alleviated by inclusion of retinoic acid and hydrocortisone or dexamethasone in the culture medium. These physiological effectors, which are known to have opposing actions on keratinocyte character in SCC cells, did not significantly alter either aryl hydrocarbon hydroxylase activity or macromolecular adduct formation. Further analysis of the cellular responses indicated that hydrocortisone and, in some experiments, retinoids increased the growth rate in 3-MC-exposed cultures, while 3-MC increased the saturation density in retinoic acid-exposed cultures, an example of interference with a physiological response of the cells. These results indicate that alteration of the differentiated state, regardless of the direction of the change, can alter the sensitivity of these cells to toxic stimuli. Further investigation of the bases of such toxic responses and their modulation by the microenvironment may enhance our understanding of the target cell specificity of polycyclic aromatic hydrocarbons.

  16. Induction of 26S proteasome subunit PSMB5 by the bifunctional inducer 3-methylcholanthrene through the Nrf2-ARE, but not the AhR/Arnt-XRE, pathway

    SciTech Connect

    Kwak, Mi-Kyoung . E-mail: mkwak@yumail.ac.kr; Kensler, Thomas W.

    2006-07-14

    The 26S proteasome is responsible for degradation of abnormal intracellular proteins, including oxidatively damaged proteins and may play a role as a component of a cellular antioxidative system. However, little is known about regulation of proteasome expression. In the present study, regulation of proteasome expression by the bifunctional enzyme inducer and a specific signaling pathway for this regulation were investigated in murine neuroblastoma cells. Expression of catalytic core subunits including PSMB5 and peptidase activities of the proteasome were elevated following incubation with 3-methylcholanthrene (3-MC). Studies using reporter genes containing the murine Psmb5 promoter showed that transcriptional activity of this gene was enhanced by 3-MC. Overexpression of AhR/Arnt did not affect activation of the Pmsb5 promoter by 3-MC and deletion of the xenobiotic response elements (XREs) from this promoter exerted modest effects on inducibility in response to 3-MC. However, mutation of the proximal AREs of the Psmb5 promoter largely abrogated its inducibility by 3-MC. In addition, this promoter showed a blunted response toward 3-MC in the absence of nrf2; 3-MC incubation increased nuclear levels of Nrf2 only in wild-type cells. Collectively, these results indicate that expression of proteasome subunit PSMB5 is modulated by bifunctional enzyme inducers in a manner independent of the AhR/Arnt-XRE pathway but dependent upon the Nrf2-ARE pathway.

  17. Modulating role of pheromonal cues from oestrus-specific urine on 3-methylcholanthrene-induced male reproductive toxicity.

    PubMed

    Suriyakalaa, U; Gayathiri, R; SankarGanesh, D; Kokilavani, P; Sukirtha, R; Ramachandran, R; Kamalakkannan, S; Achiraman, S

    2016-09-01

    Polyaromatic hydrocarbons (PAHs) are persistent organic pollutants that contribute to endocrine/gonadal disruption. This study was designed to investigate the endocrine modulating role of pheromones in alleviating the reproductive toxic effects of 3-MC (3-methylcholanthrene), one of the common PAHs, in rat model. The rats were injected intraperitoneally with 3-MC at a dose of 25 mg kg(-1) BW. The serum levels of testosterone and other biochemical parameters were altered to significant levels in 3-MC-treated rats and oestrus-specific urine exposure restored all these effects to near normal. Although testis weight did not indicate any significant change, sperm and spermatid counts were significantly reduced in 3-MC-treated rats, which became normal in oestrus-urine-exposed rats. Hence, this study suggests that oestrus-specific urinary pheromones have the potential to modulate the endocrine system and alleviate the male reproductive toxic effects produced by 3-MC. PMID:26715617

  18. Aqueous Tear Deficiency Increases Conjunctival Interferon-γ (IFN-γ) Expression and Goblet Cell Loss

    PubMed Central

    Pflugfelder, Stephen C.; De Paiva, Cintia S.; Moore, Quianta L.; Volpe, Eugene A.; Li, De-Quan; Gumus, Koray; Zaheer, Mahira L.; Corrales, Rosa M.

    2015-01-01

    Purpose To investigate the hypothesis that increased interferon-γ (IFN-γ) expression is associated with conjunctival goblet cell loss in subjects with tear dysfunction. Methods Goblet cell density (GCD) was measured in impression cytology from the temporal bulbar conjunctiva, and gene expression was measured in cytology samples from the nasal bulbar conjunctiva obtained from 68 subjects, including normal control, meibomian gland disease (MGD), non-Sjögren syndrome (non-SSATD)-, and Sjögren syndrome (SSATD)-associated aqueous tear deficiency. Gene expression was evaluated by real-time PCR. Tear meniscus height (TMH) was measured by optical coherence tomography. Fluorescein and lissamine green dye staining evaluated corneal and conjunctival disease, respectively. Between-group mean differences and correlation coefficients were calculated. Results Compared to control, IFN-γ expression was significantly higher in both ATD groups, and its receptor was higher in SSATD. Expression of IL-13 and its receptor was similar in all groups. Goblet cell density was lower in the SSATD group; expression of MUC5AC mucin was lower and cornified envelope precursor small proline-rich region (SPRR)-2G higher in both ATD groups. Interferon-γ transcript number was inversely correlated with GCD (r = −0.37, P < 0.04) and TMH (r = −0.37, P = 0.02), and directly correlated with lissamine green staining (r = 0.51, P < 0.001) and SPRR-2G expression (r = 0.32, P < 0.05). Conclusions Interferon-γ expression in the conjunctiva was higher in aqueous deficiency and correlated with goblet cell loss and severity of conjunctival disease. These results support findings of animal and culture studies showing that IFN-γ reduces conjunctival goblet cell number and mucin production. PMID:26618646

  19. Benzo[a]pyrene, 3-methylcholanthrene and beta-naphthoflavone induce oxidative stress in hepatoma hepa 1c1c7 Cells by an AHR-dependent pathway.

    PubMed

    Elbekai, Reem H; Korashy, Hesham M; Wills, Kelly; Gharavi, Negar; El-Kadi, Ayman O S

    2004-11-01

    Polycyclic aromatic hydrocarbons have been shown to cause oxidative stress in vitro and in vivo in various animal models but the mechanisms by which these compounds produce oxidative stress are unknown. In the current study we have investigated the role of the aryl hydrocarbon receptor (AHR) in the production of reactive oxygen species (ROS) by its cognate ligands and the consequent effect on cyp1a1 activity, mRNA and protein expressions. For this purpose, Hepa 1c1c7 cells wild-type (WT) and C12 mutant cells, which are AHR-deficient, were incubated with increasing concentrations of the AHR-ligands, benzo[a]pyrene (B[a]P, 0.25-25 microM), 3-methylcholanthrene (3MC, 0.1-10 microM) and beta-naphthoflavone (betaNF, 1-50 microM). The studied AHR-ligands dose-dependently increased lipid peroxidation in WT but not in C12 cells. However, only B[a]P and betaNF, at the highest concentrations tested, significantly increased H2O2 production in WT but not C12 cells. The increase in lipid peroxidation and H2O2 production by AHR-ligands were accompanied by a decrease in the cyp1a1 catalytic activity but not mRNA or protein expressions, which were significantly induced in a dose-dependent manner by all AHR-ligands, suggesting a post-translational mechanism is involved in the decrease of cyp1a1 activity. The AHR-ligand-mediated decrease in cyp1a1 activity was reversed by the antioxidant N-acetylcysteine. Our results show that the AHR-ligands induce oxidative stress by an AHR-dependent pathway. PMID:15621696

  20. Cutting Edge: Autoimmune Disease Risk Variant of STAT4 Confers Increased Sensitivity to IFN-α in Lupus Patients In Vivo1

    PubMed Central

    Kariuki, Silvia N.; Kirou, Kyriakos A.; MacDermott, Emma J.; Barillas-Arias, Lilliana; Crow, Mary K.; Niewold, Timothy B.

    2009-01-01

    Increased IFN-α signaling is a primary pathogenic factor in systemic lupus erythematosus (SLE). STAT4 is a transcription factor that is activated by IFN-α signaling, and genetic variation of STAT4 has been associated with risk of SLE and rheumatoid arthritis. We measured serum IFN-α activity and simultaneous IFN-α-induced gene expression in PBMC in a large SLE cohort. The risk variant of STAT4 (T allele; rs7574865) was simultaneously associated with both lower serum IFN-α activity and greater IFN-α-induced gene expression in PBMC in SLE patients in vivo. Regression analyses confirmed that the risk allele of STAT4 was associated with increased sensitivity to IFN-α signaling. The IFN regulatory factor 5 SLE risk genotype was associated with higher serum IFN-α activity; however, STAT4 showed dominant influence on the sensitivity of PBMC to serum IFN-α. These data provide biologic relevance for the risk variant of STAT4 in the IFN-α pathway in vivo. PMID:19109131

  1. Despite Increased Type 1 IFN, Autoimmune Nonobese Diabetic Mice Display Impaired Dendritic Cell Response to CpG and Decreased Nuclear Localization of IFN-Activated STAT1.

    PubMed

    Rahman, M Jubayer; Rahir, Gwendoline; Dong, Matthew B; Zhao, Yongge; Rodrigues, Kameron B; Hotta-Iwamura, Chie; Chen, Ye; Guerrero, Alan; Tarbell, Kristin V

    2016-03-01

    Innate immune signals help break self-tolerance to initiate autoimmune diseases such as type 1 diabetes, but innate contributions to subsequent regulation of disease progression are less clear. Most studies have measured in vitro innate responses of GM-CSF dendritic cells (DCs) that are functionally distinct from conventional DCs (cDCs) and do not reflect in vivo DC subsets. To determine whether autoimmune NOD mice have alterations in type 1 IFN innate responsiveness, we compared cDCs from prediabetic NOD and control C57BL/6 (B6) mice stimulated in vivo with the TLR9 ligand CpG, a strong type 1 IFN inducer. In response to CpG, NOD mice produce more type 1 IFN and express higher levels of CD40, and NOD monocyte DCs make more TNF. However, the overall CpG-induced transcriptional response is muted in NOD cDCs. Of relevance the costimulatory proteins CD80/CD86, signals needed for regulatory T cell homeostasis, are upregulated less on NOD cDCs. Interestingly, NOD Rag1(-/-) mice also display a defect in CpG-induced CD86 upregulation compared with B6 Rag1(-/-), indicating this particular innate alteration precedes adaptive autoimmunity. The impaired response in NOD DCs is likely downstream of the IFN-α/β receptor because DCs from NOD and B6 mice show similar CpG-induced CD86 levels when anti-IFN-α/β receptor Ab is added. IFN-α-induced nuclear localization of activated STAT1 is markedly reduced in NOD CD11c(+) cells, consistent with lower type 1 IFN responsiveness. In conclusion, NOD DCs display altered innate responses characterized by enhanced type 1 IFN and activation of monocyte-derived DCs but diminished cDC type 1 IFN response. PMID:26826238

  2. IFN-λs.

    PubMed

    Kotenko, Sergei V

    2011-10-01

    For decades, type I IFNs have been considered indispensable and unique antiviral mediators for the activation of rapid innate antiviral protection. However, the recent discovery of type III IFNs is challenging this paradigm. Since their identification in 2002/2003 by two independent groups, type III IFNs or IFN-λs, also known as IL-28/29, have been the subject of increased study with consequent recognition of their importance in virology and immunology. Initial reports suggested that IFN-λs functionally resemble type I IFNs. Although IFN-λs and classical type I IFNs (IFN-α/β) utilize distinct receptor complexes for signaling, both types of IFNs activate similar intracellular signaling pathways and biological activities, including the ability to induce antiviral state in cells, and both type I and type III IFNs are induced by viral infection. However, different antiviral potency, pattern of their induction and differential tissue expression of their corresponding receptor subunits suggest that the type I and type III IFN antiviral systems do not merely duplicate each other. Recent studies have started to reveal unique biological activities of IFN-λs in and beyond innate antiviral immunity. PMID:21840693

  3. Increased IL-2, IL-4 and interferon-gamma (IFN-gamma) in steroid-sensitive nephrotic syndrome.

    PubMed Central

    Neuhaus, T J; Wadhwa, M; Callard, R; Barratt, T M

    1995-01-01

    We investigated the production of cytokines by peripheral blood mononuclear cells (PBMC) and serum cytokine concentrations in children with steroid-sensitive idiopathic nephrotic syndrome (SSNS). PBMC from patients off treatment were collected during remission and relapse and cultured in medium alone or stimulated with calcium ionophore plus phorbol myristate acetate. Control PBMC were taken from healthy age-matched children. IL-2 was measured by bioassay, IL-4 by immunoradiometric assay, and IL-8 and IFN-gamma by ELISA. After 24 h culture without stimulation, IL-2, IL-4 and IFN-gamma were not detectable in the supernatant in any of the children. After stimulation, the supernatant concentrations of IL-2 (median 172 U/ml at 24 h) and IL-4 (160 pg/ml at 24 h; 210 pg/ml at 72 h) were significantly increased in relapse compared with remission (IL-2 37 U/ml; IL-4 65 pg/ml and 60 pg/ml) and controls (IL-2 69 U/ml; IL-4 40 pg/ml and 40 pg/ml) (P < 0.05). The concentration of IFN-gamma was not significantly increased in relapse compared with remission and controls (600, 325, and 145 U/ml, respectively, at 72 h). IL-8 concentrations were similar in relapse, remission and controls with stimulation (median 32, 40 and 40 ng/ml, respectively) and without (30, 17 and 10 ng/ml). IL-2 was not detectable in serum, but IL-4, IL-8 and IFN-gamma were measurable in about half the patients, both in relapse and remission, though were virtually undetectable in controls. We conclude that relapse of SSNS in children is associated with T lymphocyte activation with release of IL-2, IL-4 and IFN-gamma. PMID:7774059

  4. Developmental regulation of the 3-methylcholanthrene- and dioxin-inducible CYP1A5 gene in chick embryo liver in vivo.

    PubMed

    Bentivegna, C S; Ihnat, M A; Baptiste, N S; Hamilton, J W

    1998-07-01

    The cDNA sequences for two dioxin-inducible cytochrome P450s in chicken, CYP1A4 and CYP1A5, have recently been reported which correspond to two dioxin-inducible forms of P450 previously designated as TCDDAHH and TCDDAA, respectively. The developmental expression of CYP1A4-associated aryl hydrocarbon (benzo[a]pyrene) hydroxylase (AHH) activity and its association with expression of the Ah receptor had previously been characterized in chick embryo liver. The purpose of this study was to examine the developmental regulation of the second dioxin-inducible P450 gene, CYP1A5, in chick embryo liver. A partial gene sequence for CYP1A5 indicated that the intron/exon organization of this gene was identical to that of the CYP1A1 and CYP1A2 mammalian genes and was present in a single copy in the genome. CYP1A5 mRNA was expressed basally in chick embryo liver and was highly inducible by the Ah receptor ligands, 3-methylcholanthrene, beta-naphthoflavone, and 3,4,3', 4'-tetrachlorobiphenyl (TCB), but not by the phenobarbital analog, glutethimide. CYP1A5 mRNA levels were increased 40- to 50-fold within 5 h after a single TCB treatment, corresponding to a 30- to 40-fold increase in the transcription rate of the CYP1A5 gene at this time point. In contrast to a previous report that CYP1A5 mRNA expression was inducible by estradiol, we observed no effects of estradiol or dexamethasone on CYP1A5 mRNA expression, either alone or in combination with TCB. Basal and TCB-inducible CYP1A5 mRNA expression was maximal in liver at 8 days of development and remained high throughout the remainder of embryonic development. Thus, CYP1A5 appears to be regulated in a very similar manner to CYP1A4 in chick embryo liver. PMID:9705900

  5. An increase in galectin-3 causes cellular unresponsiveness to IFN-γ-induced signal transduction and growth inhibition in gastric cancer cells

    PubMed Central

    Tseng, Po-Chun; Chen, Chia-Ling; Shan, Yan-Shen; Lin, Chiou-Feng

    2016-01-01

    Glycogen synthase kinase (GSK)-3β facilitates interferon (IFN)-γ signaling by inhibiting Src homology-2 domain-containing phosphatase (SHP) 2. Mutated phosphoinositide 3-kinase (PI3K) and phosphatase and tensin homolog (PTEN) cause AKT activation and GSK-3β inactivation to induce SHP2-activated cellular unresponsiveness to IFN-γ in human gastric cancer AGS cells. This study investigated the potential role of galectin-3, which acts upstream of AKT/GSK-3β/SHP2, in gastric cancer cells. Increasing or decreasing galectin-3 altered IFN-γ signaling. Following cisplatin-induced galectin-3 upregulation, surviving cells showed cellular unresponsiveness to IFN-γ. Galectin-3 induced IFN-γ resistance independent of its extracellular β-galactoside-binding activity. Galectin-3 expression was not regulated by PI3K activation or by a decrease in PTEN. Increased galectin-3 may cause GSK-3β inactivation and SHP2 activation by promoting PDK1-induced AKT phosphorylation at a threonine residue. Overexpression of AKT, inactive GSK-3βR96A, SHP2, or active SHP2D61A caused cellular unresponsiveness to IFN-γ in IFN-γ-sensitive MKN45 cells. IFN-γ-induced growth inhibition and apoptosis in AGS cells were observed until galectin-3 expression was downregulated. These results demonstrate that an increase in galectin-3 facilitates AKT/GSK-3β/SHP2 signaling, causing cellular unresponsiveness to IFN-γ. PMID:26934444

  6. TNF, IFN, AND ENDOTOXIN INCREASE EXPRESSION OF DMT-1 IN BRONCHIAL EPITHELIAL CELLS

    EPA Science Inventory

    Regulation of the metal transport protein DMT1 may contribute to the uptake and detoxification of iron by cells resident in the respiratory tract. Inflammation has been associated with an increased availability of this metal resulting in an oxidative stress. Because pro-inflamm...

  7. Age-Related Increases in Basal Ganglia Glutamate are Associated with TNF-Alpha, Reduced Motivation and Decreased Psychomotor Speed During IFN-alpha Treatment: Preliminary Findings

    PubMed Central

    Haroon, Ebrahim; Felger, Jennifer C.; Woolwine, Bobbi J.; Chen, Xiangchuan; Parekh, Samir; Spivey, James; Hu, Xiaoping; Miller, Andrew H.

    2014-01-01

    Inflammation-induced alterations in central nervous system (CNS) metabolism have focused on glutamate. At excessive concentrations, glutamate is toxic to glia and neurons, and inflammatory cytokines have been shown to influence glutamate metabolism by blocking glutamate reuptake and increasing glutamate release. Increased glutamate has also been found in depression, a disorder associated with increased inflammation. Data by our group have shown increased glutamate as measured by magnetic resonance spectroscopy (MRS) in basal ganglia and dorsal anterior cingulate cortex of patients administered the inflammatory cytokine interferon (IFN)-alpha. Given data that increasing age is associated with an exaggerated CNS inflammatory response, we examined whether older age (>55 years) would be associated with a greater IFN-alpha-induced increase in CNS glutamate. Using a longitudinal design, 31 patients with hepatitis C virus (HCV) underwent MRS, blood sampling for inflammatory markers, and behavioral assessments before (Visit1) and after four weeks (Visit 2) of either IFN-alpha (n=17) or no treatment (n=14). Older patients treated with IFN-alpha exhibited a significantly increased glutamate from Visit 1 to Visit 2 as reflected by the glutamate/creatine ratio (Glu/Cr) in left basal ganglia compared to older controls and younger IFN-alpha-treated and untreated subjects. In addition, increased Glu/Cr in older but not younger IFN-alpha-treated and untreated patients was associated with increased tumor necrosis factor, reduced motivation as measured by the Multidimensional Fatigue Inventory and increased choice movement time on the Cambridge Neuropsychological Test Automated Battery. Taken together, these preliminary data support the notion that older age may interact with inflammation to exaggerate the effects of inflammatory stimuli on CNS glutamate and behavior. PMID:25500218

  8. 3-Methylcholanthrene elicits DNA adduct formation in the CYP1A1 promoter region and attenuates reporter gene expression in rat H4IIE cells

    SciTech Connect

    Moorthy, Bhagavatula . E-mail: bmoorthy@bcm.tmc.edu; Muthiah, Kathirvel; Fazili, Inayat S.; Kondraganti, Sudha R.; Wang Lihua; Couroucli, Xanthi I.; Jiang Weiwu

    2007-03-23

    Cytochrome CYP1A (CYP1A) enzymes catalyze bioactivation of 3-methylcholanthrene (MC) to genotoxic metabolites. Here, we tested the hypothesis that CYP1A2 catalyzes formation of MC-DNA adducts that are preferentially formed in the promoter region of CYP1A1, resulting in modulation of CYP1A1 gene expression. MC bound covalently to plasmid DNA (50 {mu}g) containing human CYP1A1 promoter (pGL3-1A1), when incubated with wild-type (WT) liver microsomes (2 mg) and NAPPH 37 {sup o}C for 2 h, giving rise to 9 adducts, as determined by {sup 32}P-postlabeling. Eighty percent of adducts was located in the promoter region. Transient transfection of the adducted plasmids into rat hepatoma (H4IIE) cells for 16 h, followed by MC (1 {mu}M) treatment for 24 h inhibited reporter (luciferase) gene expression by 75%, compared to unadducted controls. Our results suggest that CYP1A2 plays a key role in sequence-specific MC-DNA adduct formation in the CYP1A1 promoter region, leading to attenuation of CYP1A1 gene expression.

  9. Differential metabolism of acetanilide versus ethoxycoumarin and benzo[a]pyrene by two 3-methylcholanthrene-inducible forms of rat liver cytochrome P-450.

    PubMed

    Sundheimer, D W; Caveness, M B; Goldstein, J A

    1983-10-15

    The present study compares the catalytic activities of two 3-methylcholanthrene (3-MC) inducible forms of cytochrome P-450. These isozymes (P-448HCB and P-448MC) were isolated from liver microsomes of rats treated with 3,4,5,3',4',5'-hexachlorobiphenyl (HCB) and 3-MC, respectively. Catalytic activities of the isozymes were compared in a reconstituted system and by antibody inhibition studies in microsomes. In a reconstituted system, P-448HCB had very little catalytic activity toward benzo[a]pyrene or ethoxycoumarin (substrates metabolized preferentially by P-448MC). In contrast, both isozymes had high turnover numbers for aniline and acetanilide. However, catalytic activities of the purified isozymes were affected dramatically by Emulgen 911, a nonionic detergent. Since nonionic detergents used in the purification of P-450 isozymes cannot be completely removed after purification, residual amounts of detergent probably affect turnover numbers in a reconstituted system. Therefore, specific antibodies to cytochromes P-448MC and P-448HCB were used to examine the contribution of these isozymes to microsomal metabolism. Antibody inhibition studies confirmed that the majority of benzo[a]pyrene and ethoxycoumarin metabolism in 3-MC-induced microsomes was catalyzed by cytochrome P-448MC. In contrast, P-448HCB accounted for the majority of the acetanilide hydroxylase activity in 3-MC- and HCB-induced microsomes. Neither isozyme contributed appreciably to metabolism of these substrates in control microsomes. PMID:6314905

  10. The effect of pyrazole, phenobarbital, ethanol and 3-methylcholanthrene pretreatment on the in vivo and in vitro genotoxicity of N-nitrosopyrrolidine.

    PubMed

    Gold, B; Brunk, G

    1988-06-01

    The in vitro genotoxicity of N-nitrosopyrrolidine (NPy) has been studied in Salmonella typhimurium strain TA1535 in the presence of untreated and pyrazole-, phenobarbital (PB)-, 4-day ethanol (EtOH)-, 10-day EtOH- and 3-methylcholanthrene (3-MC)-pretreated male Sprague-Dawley rat liver S-9 fractions. Unless stated otherwise, the last pretreatment exposure was 24 h prior to sacrifice and isolation of hepatic enzymes. Pyrazole and EtOH (10-day exposure) both effectively induced the conversion of NPy into a mutagen at doses as low as 500 microM. PB and EtOH (4-day exposure) had a modest enhancing effect on the number of revertants scored, while 3-MC and uninduced S-9 fractions gave results not significantly different from background (no NPy). The same pretreatment protocols were used to determine the in vivo genotoxicity of NPy in rat liver using the technique of alkaline elution. The inducing agents had the exact opposite effect in vivo with control, 3-MC- and 4-day EtOH-treated animals showing the highest level of DNA damage. Pyrazole and 10-day EtOH pretreatments gave DNA elution rate constants comparable to animals not treated with NPy. However, in 10-day EtOH-pretreated animals which were administered NPy without a 24-h interval between EtOH and NPy exposure, DNA damage was observed at the same high levels as was seen in uninduced and 3-MC treated rats. The results are discussed in terms of a detoxification role for microsomal proteins and that the observed in vivo DNA damage may be induced by enzymes associated with the nuclear compartment. PMID:3286025

  11. Basal and 3-methylcholanthrene-induced expression of cytochrome P450 1A, 1B and 1C genes in the Brazilian guppy, Poecilia vivipara

    PubMed Central

    Dorrington, Tarquin; Zanette, Juliano; Zacchi, Flávia L.; Stegeman, John J.; Bainy, Afonso C.D.

    2015-01-01

    In fish there are four cytochrome P450 (CYP1) subfamilies: CYP1A, CYP1B, CYP1C, and CYP1D. Here we cloned Poecilia vivipara CYP1A, with an inferred amino acid sequence 91% identical to CYP1A from the killifish Fundulus heteroclitus, another member of the Cypriniformes, and an important model in ecotoxicology. In addition, we examined the expression of CYP1A, CYP1B1, and CYP1C1 by qPCR in liver, gill, and intestine of adult P. vivipara injected with 3-methylcholanthrene (3-MC) or held in clean water (control group) for 24 h. All three tissues examined showed basal expression of the three CYP1 genes. CYP1A was most strongly expressed in the liver, while CYP1B1, and CYP1C1 were most strongly expressed in the gill and intestine respectively. 3-MC induced CYP1A, CYP1B1, and CYP1C1 significantly (20–120-fold) in the three organs, consistent with the regulation of CYP1A, CYP1B1 and CYP1C1 via the aryl hydrocarbon receptor. Validation of CYP1 gene biomarkers in fish collected from a contaminated urban mangrove environment was confirmed with significant induction of CYP1A and CYP1C1 in gills (10–15-fold) and CYP1B1 in liver (23-fold), relative to fish from a control site. The responsiveness of these CYP1 genes indicates P. vivipara is suitable as a model for environmental toxicology studies and environmental assessment in Brazil. PMID:22940225

  12. Flavin-containing monooxygenase-3: induction by 3-methylcholanthrene and complex regulation by xenobiotic chemicals in hepatoma cells and mouse liver1

    PubMed Central

    Celius, Trine; Pansoy, Andrea; Matthews, Jason; Okey, Allan B.; Henderson, Marilyn C.; Krueger, Sharon K.; Williams, David E.

    2010-01-01

    Flavin-containing monooxygenases often are thought not to be inducible but we recently demonstrated aryl hydrocarbon receptor (AHR)-dependent induction of FMO mRNAs in mouse liver by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (Celius et al., Drug Metab Dispos 36:2499, 2008). We now evaluated FMO induction by other AHR ligands and xenobiotic chemicals in vivo and in mouse Hepa1c1c7 hepatoma cells (Hepa-1). In mouse liver, 3-methylcholanthrene (3MC) induced FMO3 mRNA 8-fold. In Hepa-1 cells, 3MC and benzo[a]pyrene (BaP) induced FMO3 mRNA >30-fold. Induction by 3MC and BaP was AHR-dependent but, surprisingly, the potent AHR agonist, TCDD, did not induce FMO3 mRNA in Hepa-1 cells nor did chromatin immunoprecipitation assays detect recruitment of AHR or ARNT to Fmo3 regulatory elements after exposure to 3MC in liver or in Hepa-1 cells. However, in Hepa-1, 3MC and BaP (but not TCDD) caused recruitment of p53 protein to a p53 response element in the 5'-flanking region of the Fmo3 gene. We tested the possibility that FMO3 induction in Hepa-1 cells might be mediated by Nrf2/antioxidant response pathways but agents known to activate Nrf2 or to induce oxidative stress did not affect FMO3 mRNA levels. The protein synthesis inhibitor, cycloheximide (which causes “superinduction” of CYP1A1 mRNA in TCDD-treated cells) by itself caused dramatic upregulation (>300-fold) of FMO3 mRNA in Hepa-1 suggesting that cycloheximide prevents synthesis of a labile protein that suppresses FMO3 expression. Although FMO3 mRNA is highly induced by 3MC or TCDD in mouse liver and in Hepa-1 cells, FMO protein levels and FMO catalytic function showed only modest elevation. PMID:20570689

  13. Multiple forms of cytochrome P-450 purified from liver microsomes of phenobarbital- and 3-methylcholanthrene-pretreated rabbits. II. Spectral properties.

    PubMed

    Hashimoto-Yutsudo, C; Imai, Y; Sato, R

    1980-08-01

    The spectral properties of multiple forms of cytochrome P-450 purified or partially purified from liver microsomes of phenobarbital (PB)- and 3-methylcholanthrene (MC)-treated rabbits have been studied. Both optical absorption and EPR studies have shown that the oxidized forms of P-450(1), P-450(2) (from PB-treated animals), and P-450(3) (from MC-treated animals) are in the low spin state, having a Soret absorption peak at 417-418 nm. Oxidized P-448(1) (from both PB- and MC-treated animals), on the other hand, shows a Soret peak at 393 nm and a weak band at 646 nm. This and EPR evidence indicate that P-448(1) contains heme which is predominantly in the high spin state, though EPR studies at low temperature indicate the presence of a small amount of low spin ferric heme. The presence of tightly bound MC in P-448(1) purified from MM-treated animals is reflected by characteristic absorption peaks in the ultraviolet region, but this does not affect the absorption spectra in the Soret and visible regions. Emulgen 913, a nonionic detergent, causes the conversion of oxidized P-448(1) from the high to the low spin state, as evidenced by optical absorption and EPR results; bound MC inhibits this conversion in a noncompetitive way. Binding of ethyl isocyanide to reduced P-450(1) and P-448(1) results in the appearance of two Soret peaks in the 430 and 455 nm regions, the relative intensities of which are dependent on pH. At any pH the 455 nm peak of P-448(1) is always higher than that of P-450(1). Benzphetamine and aniline, added to oxidized P-450(1), cause Type I and Type II spectral changes, respectively, but the magnitudes of the changes are small in both cases. The Soret peak of oxidized P-448(1) at 393 nm is completely shifted to 420 nm on addition of aniline, resulting in a reverse Type I spectral change; acetanilide causes the conversion of the Soret peak to the low spin state to only a slight extent. The conversions caused by aniline and acetanilide are both inhibited

  14. Flavin-containing monooxygenase-3: Induction by 3-methylcholanthrene and complex regulation by xenobiotic chemicals in hepatoma cells and mouse liver

    SciTech Connect

    Celius, Trine; Pansoy, Andrea; Matthews, Jason; Okey, Allan B.; Henderson, Marilyn C.; Krueger, Sharon K.; Williams, David E.

    2010-08-15

    Flavin-containing monooxygenases often are thought not to be inducible but we recently demonstrated aryl hydrocarbon receptor (AHR)-dependent induction of FMO mRNAs in mouse liver by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (Celius et al., Drug Metab Dispos 36:2499, 2008). We now evaluated FMO induction by other AHR ligands and xenobiotic chemicals in vivo and in mouse Hepa1c1c7 hepatoma cells (Hepa-1). In mouse liver, 3-methylcholanthrene (3MC) induced FMO3 mRNA 8-fold. In Hepa-1 cells, 3MC and benzo[a]pyrene (BaP) induced FMO3 mRNA > 30-fold. Induction by 3MC and BaP was AHR dependent but, surprisingly, the potent AHR agonist, TCDD, did not induce FMO3 mRNA in Hepa-1 cells nor did chromatin immunoprecipitation assays detect recruitment of AHR or ARNT to Fmo3 regulatory elements after exposure to 3MC in liver or in Hepa-1 cells. However, in Hepa-1, 3MC and BaP (but not TCDD) caused recruitment of p53 protein to a p53 response element in the 5'-flanking region of the Fmo3 gene. We tested the possibility that FMO3 induction in Hepa-1 cells might be mediated by Nrf2/anti-oxidant response pathways, but agents known to activate Nrf2 or to induce oxidative stress did not affect FMO3 mRNA levels. The protein synthesis inhibitor, cycloheximide (which causes 'superinduction' of CYP1A1 mRNA in TCDD-treated cells), by itself caused dramatic upregulation (> 300-fold) of FMO3 mRNA in Hepa-1 suggesting that cycloheximide prevents synthesis of a labile protein that suppresses FMO3 expression. Although FMO3 mRNA is highly induced by 3MC or TCDD in mouse liver and in Hepa-1 cells, FMO protein levels and FMO catalytic function showed only modest elevation.

  15. A novel gain-of-function STAT1 mutation resulting in basal phosphorylation of STAT1 and increased distal IFN-γ-mediated responses in chronic mucocutaneous candidiasis.

    PubMed

    Martinez-Martinez, Laura; Martinez-Saavedra, Maria Teresa; Fuentes-Prior, Pablo; Barnadas, Maria; Rubiales, Maria Victoria; Noda, Judith; Badell, Isabel; Rodríguez-Gallego, Carlos; de la Calle-Martin, Oscar

    2015-12-01

    Gain-of-function STAT1 mutations have recently been associated with autosomal dominant chronic mucocutaneous candidiasis (CMC). The purpose of this study was to characterize the three members of a non-consanguineous family, the father and his two sons, who presented with recurrent oral thrush and ocular candidiasis since early childhood. The three patients had reduced levels of IL-17-producing T cells. This reduction affected specifically IL-17(+)IFN-γ(-) T cells, because the levels of IL-17(+)IFN-γ(+) T cells were similar to controls. We found that PBMC (peripheral blood mononuclear cells) from the patients did not respond to Candida albicans ex vivo. Moreover, after polyclonal activation, patients' PBMC produced lower levels of IL-17 and IL-6 and higher levels of IL-4 than healthy controls. Genetic analyses showed that the three patients were heterozygous for a new mutation in STAT1 (c.894A>C, p.K298N) that affects a highly conserved residue of the coiled-coil domain of STAT1. STAT1 phosphorylation levels were significantly higher in patients' cells than in healthy controls, both in basal conditions and after IFN-γ stimulation, suggesting a permanent activation of STAT1. Cells from the patients also presented increased IFN-γ-mediated responses measured as MIG and IP-10 production. In conclusion, we report a novel gain-of-function mutation in the coiled-coil domain of STAT1, which increases STAT1 phosphorylation and impairs IL-17-mediated immunity. The mutation is responsible for CMC in this family with autosomal dominant inheritance of the disease. PMID:26514428

  16. Downregulation of intragraft IFN-gamma expression correlates with increased IgG1 alloantibody response following intrathymic immunomodulation of sensitized rat recipients.

    PubMed

    Binder, J; Graser, E; Hancock, W W; Wasowska, B; Sayegh, M H; Volk, H D; Kupiec-Weglinski, J W

    1995-12-27

    A single intrathymic injection of donor-specific spleen cells (2 x 10(7)) abrogates accelerated (24 hr) rejection of LBNF1 cardiac allografts in presensitized LEW rats and prolongs graft survival to about 11 days. This effect is donor-specific, gamma-irradiation-sensitive, thymus-dependent, and requires no concomitant therapy. We have recently shown that following intrathymic alloantigen administration, there is an earlier and increased systemic production of alloreactive IgM, and subsequently a premature isotype switching to IgG with the predominant IgG1 and IgG2a alloantibody responses. There is also a preferential binding of these IgG subclasses to the endothelium of well-functioning allografts. In this work, we analyzed the early cell activation and related cytokine elaboration patterns at the mRNA and protein levels by competitive template RT-PCR and immunohistochemistry, respectively. We found that prolonged cardiac allograft survival following intrathymic administration of donor spleen cells in presensitized rats was associated with markedly depressed intragraft IFN gamma mRNA and protein expression. Moreover, intrathymic allostimulation has led to a defect in the IL-2 pathway as the expression of IL-2 and IL-2R protein at the graft site was inhibited despite stable IL-2 mRNA levels. The inhibition of cell activation was also demonstrated by reduced MHC class II and the lack of ICAM-1, and TNF-alpha expression by immunohistochemistry. The expression of biologically active IL-12 (p70) by mononuclear and endothelial cells was detected in rejecting grafts between 3 and 12 hr. The well-functioning grafts after intrathymic allostimulation were devoid of IL-12 (p70), which in turn may have contributed to the downregulation of IFN-gamma mRNA and protein. Treatment with r.IFN-gamma, but not with r.IL-2, recreated the rejection response, and the characteristic IgG subclass pattern associated with accelerated graft loss. Hence, intrathymic immunomodulation with

  17. Diminished CD4+/CD25+ T cell and increased IFN-gamma levels occur in dogs vaccinated with Leishmune in an endemic area for visceral leishmaniasis.

    PubMed

    de Lima, Valéria Marçal Felix; Ikeda, Fabiana Augusta; Rossi, Cláudio N; Feitosa, Mary Marcondes; Vasconcelos, Rosemeride Oliveira; Nunes, Caris Maroni; Goto, Hiro

    2010-06-15

    The Leishmune vaccine has been used in endemic areas to prevent canine visceral leishmaniasis in Brazil, but cytokine production induced by vaccination has rarely been investigated in dogs. This study aimed to evaluate the immune response of dogs vaccinated with Leishmune FML vaccine (Fort Dodge) against total antigen of Leishmania (Leishmania) chagasi (TAg) and FML. Twenty healthy dogs from Araçatuba, São Paulo, Brazil, an endemic leishmaniasis area, received three consecutive subcutaneous injection of Leishmune vaccine at 21-day intervals. PBMC were isolated before and 10 days after completing vaccination and lymphoproliferative response and antibody production against FML or total promastigote antigen were tested. Cytokines IFN-gamma, IL-4 and TNF-alpha were measured in culture supernatant and CD4+/CD25+ and CD8+/CD25+ T cell presence was determined. Analysis of the data indicated that the vaccine conferred humoral responses (100%) against both antigens and cellular immunity to FML (85%) and total antigen (80%), the supernatant of cultured cells stimulated with TAg and FML showed an increase in IFN-gamma (P<0.05), and the vaccine reduced CD4+/CD25+ T cell presence compared to that observed before vaccination. These responses may constitute part of the immune mechanism induced by Leishmune. PMID:20132994

  18. Induction of Cyp1a1 and Cyp1b1 and formation of DNA adducts in C57BL/6, Balb/c, and F1 mice following in utero exposure to 3-methylcholanthrene

    SciTech Connect

    Xu Mian; Nelson, Garret B.; Moore, Joseph E.; McCoy, Thomas P.; Dai, Jian; Manderville, Richard A.; Ross, Jeffrey A.; Miller, Mark Steven . E-mail: msmiller@wfubmc.edu

    2005-11-15

    Fetal mice are more sensitive to chemical carcinogens than are adults. Previous studies from our laboratory demonstrated differences in the mutational spectrum induced in the Ki-ras gene from lung tumors isolated from [D2 x B6D2F1]F2 mice and Balb/c mice treated in utero with 3-methylcholanthrene (MC). We thus determined if differences in metabolism, adduct formation, or adduct repair influence strain-specific responses to transplacental MC exposure in C57BL/6 (B6), Balb/c (BC), and reciprocal F1 crosses between these two strains of mice. The induction of Cyp1a1 and Cyp1b1 in fetal lung and liver tissue was determined by quantitative fluorescent real-time PCR. MC treatment caused maximal induction of Cyp1a1 and Cyp1b1 RNA 2-8 h after injection in both organs. RNA levels for both genes then declined in both fetal organs, but a small biphasic, secondary increase in Cyp1a1 was observed specifically in the fetal lung 24-48 h after MC exposure in all four strains. Cyp1a1 induction by MC at 4 h was 2-5 times greater in fetal liver (7000- to 16,000-fold) than fetal lung (2000- to 6000-fold). Cyp1b1 induction in both fetal lung and liver was similar and much lower than that observed for Cyp1a1, with induction ratios of 8- to 18-fold in fetal lung and 10- to 20-fold in fetal liver. The overall kinetics and patterns of induction were thus very similar across the four strains of mice. The only significant strain-specific effect appeared to be the relatively poor induction of Cyp1b1 in the parental strain of B6 mice, especially in fetal lung tissue. We also measured the levels of MC adducts and their disappearance from lung tissue by the P{sup 32} post-labeling assay on gestation days 18 and 19 and postnatal days 1, 4, 11, and 18. Few differences were seen between the different strains of mice; the parental strain of B6 mice had nominally higher levels of DNA adducts 2 (gestation day 19) and 4 (postnatal day 1) days after injection, although this was not statistically

  19. Increased midgestational IFN-γ, IL-4 and IL-5 in women bearing a child with autism: A case-control study

    PubMed Central

    2011-01-01

    Background Immune anomalies have been documented in individuals with autism spectrum disorders (ASDs) and their family members. It is unknown whether the maternal immune profile during pregnancy is associated with the risk of bearing a child with ASD or other neurodevelopmental disorders. Methods Using Luminex technology, levels of 17 cytokines and chemokines were measured in banked serum collected from women at 15 to 19 weeks of gestation who gave birth to a child ultimately diagnosed with (1) ASD (n = 84), (2) a developmental delay (DD) but not autism (n = 49) or (3) no known developmental disability (general population (GP); n = 159). ASD and DD risk associated with maternal cytokine and chemokine levels was estimated by using multivariable logistic regression analysis. Results Elevated concentrations of IFN-γ, IL-4 and IL-5 in midgestation maternal serum were significantly associated with a 50% increased risk of ASD, regardless of ASD onset type and the presence of intellectual disability. By contrast, elevated concentrations of IL-2, IL-4 and IL-6 were significantly associated with an increased risk of DD without autism. Conclusion The profile of elevated serum IFN-γ, IL-4 and IL-5 was more common in women who gave birth to a child subsequently diagnosed with ASD. An alternative profile of increased IL-2, IL-4 and IL-6 was more common for women who gave birth to a child subsequently diagnosed with DD without autism. Further investigation is needed to characterize the relationship between these divergent maternal immunological phenotypes and to evaluate their effect on neurodevelopment. PMID:21810230

  20. Protection against Mycobacterium tuberculosis infection offered by a new multistage subunit vaccine correlates with increased number of IFN-γ+ IL-2+ CD4+ and IFN-γ+ CD8+ T cells.

    PubMed

    Wang, Xiaochun; Zhang, Jingyan; Liang, Jinping; Zhang, Ying; Teng, Xindong; Yuan, Xuefeng; Fan, Xionglin

    2015-01-01

    Protein subunit vaccines present a compelling new area of research for control of tuberculosis (TB). Based on the interaction between Mycobacterium tuberculosis and its host, five stage-specific antigens of M. tuberculosis that participate in TB pathogenesis--Rv1813, Rv2660c, Ag85B, Rv2623, and HspX--were selected. These antigens were verified to be recognized by T cells from a total of 42 whole blood samples obtained from active TB patients, patients with latent TB infections (LTBIs), and healthy control donors. The multistage polyprotein A1D4 was developed using the selected five antigens as a potentially more effective novel subunit vaccine. The immunogenicity and protective efficacy of A1D4 emulsified in the adjuvant MTO [monophosphoryl lipid A (MPL), trehalose-6,6'-dibehenate (TDB), components of MF59] was compared with Bacillus Calmette-Guerin (BCG) in C57BL/6 mice. Our results demonstrated that A1D4/MTO could provide more significant protection against M. tuberculosis infection than the PBS control or MTO adjuvant alone judging from the A1D4-specific Th1-type immune response; however, its efficacy was inferior to BCG as demonstrated by the bacterial load in the lung and spleen, and by the pathological changes in the lung. Antigen-specific single IL-2-secreting cells and different combinations with IL-2-secreting CD4+ T cells were beneficial and correlated with BCG vaccine-induced protection against TB. Antigen-specific IFN-γ+ IL-2+ CD4+ T cells were the only effective biomarker significantly induced by A1D4/MTO. Among all groups, A1D4/MTO immunization also conferred the highest number of antigen-specific single IFN-γ+ and IFN-γ+ TNF-α+ CD4+ T cells, which might be related to the antigen load in vivo, and single IFN-γ+ CD8+ T cells by mimicking the immune patterns of LTBIs or curable TB patients. Our strategy seems promising for the development of a TB vaccine based on multistage antigens, and subunit antigen A1D4 suspended in MTO adjuvant warrants

  1. Salmonids have an extraordinary complex type I IFN system: characterization of the IFN locus in rainbow trout oncorhynchus mykiss reveals two novel IFN subgroups.

    PubMed

    Zou, Jun; Gorgoglione, Bartolomeo; Taylor, Nicholas G H; Summathed, Thitiya; Lee, Po-Tsang; Panigrahi, Akshaya; Genet, Carine; Chen, Young-Mao; Chen, Tzong-Yueh; Ul Hassan, Mahmood; Mughal, Sharif M; Boudinot, Pierre; Secombes, Christopher J

    2014-09-01

    Fish type I IFNs are classified into two groups with two (group I) or four (group II) cysteines in the mature peptide and can be further divided into four subgroups, termed IFN-a, -b, -c, and -d. Salmonids possess all four subgroups, whereas other teleost species have one or more but not all groups. In this study, we have discovered two further subgroups (IFN-e and -f) in rainbow trout Oncorhynchus mykiss and analyzed the expression of all six subgroups in rainbow trout and brown trout Salmo trutta. In rainbow trout RTG-2 and RTS-11 cells, polyinosinic-polycytidylic acid stimulation resulted in early activation of IFN-d, whereas the IFN-e subgroup containing the highest number of members showed weak induction. In contrast with the cell lines, remarkable induction of IFN-a, -b, and -c was detected in primary head kidney leukocytes after polyinosinic-polycytidylic acid treatment, whereas a moderate increase of IFNs was observed after stimulation with resiquimod. Infection of brown trout with hemorrhagic septicemia virus resulted in early induction of IFN-d, -e, and -f and a marked increase of IFN-b and IFN-c expression in kidney and spleen. IFN transcripts were found to be strongly correlated with the viral burden and with marker genes of the IFN antiviral cascade. The results demonstrate that the IFN system of salmonids is far more complex than previously realized, and in-depth research is required to fully understand its regulation and function. PMID:25080482

  2. 5, 8, 11, 14-eicosatetraynoic acid suppresses CCL2/MCP-1 expression in IFN-γ-stimulated astrocytes by increasing MAPK phosphatase-1 mRNA stability

    PubMed Central

    2012-01-01

    Background The peroxisome proliferator-activated receptor (PPAR)-α activator, 5,8,11,14-eicosatetraynoic acid (ETYA), is an arachidonic acid analog. It is reported to inhibit up-regulation of pro-inflammatory genes; however, its underlying mechanism of action is largely unknown. In the present study, we focused on the inhibitory action of ETYA on the expression of the chemokine, CCL2/MCP-1, which plays a key role in the initiation and progression of inflammation. Methods To determine the effect of ETYA, primary cultured rat astrocytes and microglia were stimulated with IFN-γ in the presence of ETYA and then, expression of CCL2/MCP-1 and MAPK phosphatase (MKP-1) were determined using RT-PCR and ELISA. MKP-1 mRNA stability was evaluated by treating actinomycin D. The effect of MKP-1 and human antigen R (HuR) was analyzed by using specific siRNA transfection system. The localization of HuR was analyzed by immunocytochemistry and subcellular fractionation experiment. Results We found that ETYA suppressed CCL2/MCP-1 transcription and secretion of CCL2/MCP-1 protein through up-regulation of MKP-1mRNA levels, resulting in suppression of c-Jun N-terminal kinase (JNK) phosphorylation and activator protein 1 (AP1) activity in IFN-γ-stimulated brain glial cells. Moreover, these effects of ETYA were independent of PPAR-α. Experiments using actinomycin D revealed that the ETYA-induced increase in MKP-1 mRNA levels reflected an increase in transcript stability. Knockdown experiments using small interfering RNA demonstrated that this increase in MKP-1 mRNA stability depended on HuR, an RNA-binding protein known to promote enhanced mRNA stability. Furthermore, ETYA-induced, HuR-mediated mRNA stabilization resulted from HuR-MKP-1 nucleocytoplasmic translocation, which served to protect MKP-1 mRNA from the mRNA degradation machinery. Conclusion ETYA induces MKP-1 through HuR at the post-transcriptional level in a receptor-independent manner. The mechanism revealed here suggests

  3. Identification of the zebrafish IFN receptor: implications for the origin of the vertebrate IFN system.

    PubMed

    Levraud, Jean-Pierre; Boudinot, Pierre; Colin, Ingrid; Benmansour, Abdenour; Peyrieras, Nadine; Herbomel, Philippe; Lutfalla, Georges

    2007-04-01

    The recent description of virus-induced fish IFNs has raised questions about the evolution of this complex antiviral system. Identification of the receptor of the zebrafish virus-induced IFN (zIFN) was sought to help resolve these questions. We set up an experimental system to study the zIFN system in the course of a viral infection of zebrafish embryos. In this setting, zIFN was induced by viral infection, and we identified zIFN-dependent induced transcripts. Embryos quickly died from the infection, but zIFN overexpression increased their survival. We took advantage of this experimental system to perform in vivo loss and gain of function analysis of candidate receptors of the class II helical receptor family and identified zCRFB1 and zCRFB5 as the two subunits of the zebrafish IFN receptor. Based on the organization of the zIFN gene and the protein structure of the identified receptor components, the virus-induced fish IFNs appear as orthologs of mammalian IFN-lambda, specifying type III IFN as the ancestral antiviral system of vertebrates. PMID:17371995

  4. Toxoplasma gondii-skeletal muscle cells interaction increases lipid droplet biogenesis and positively modulates the production of IL-12, IFN-g and PGE2

    PubMed Central

    2014-01-01

    Background The interest in the mechanisms involved in Toxoplasma gondii lipid acquisition has steadily increased during the past few decades, but it remains not completely understood. Here, we investigated the biogenesis and the fate of lipid droplets (LD) of skeletal muscle cells (SkMC) during their interaction with T. gondii by confocal and electron microscopy. We also evaluated whether infected SkMC modulates the production of prostaglandin E2 (PGE2), cytokines interleukin-12 (IL-12) and interferon-gamma (INF-g), and also the cyclooxygenase-2 (COX-2) gene induction. Methods Primary culture of skeletal muscle cells were infected with tachyzoites of T. gondii and analysed by confocal microscopy for observation of LD. Ultrastructural cytochemistry was also used for lipid and sarcoplasmatic reticulum (SR) detection. Dosage of cytokines (IL-12 and INF-g) by ELISA technique and enzyme-linked immunoassay (EIA) for PGE2 measurement were employed. The COX-2 gene expression analysis was performed by real time reverse transcriptase polymerase chain reaction (qRT-PCR). Results We demonstrated that T. gondii infection of SkMC leads to increase in LD number and area in a time course dependent manner. Moreover, the ultrastructural analysis demonstrated that SR and LD are in direct contact with parasitophorous vacuole membrane (PVM), within the vacuolar matrix, around it and interacting directly with the membrane of parasite, indicating that LD are recruited and deliver their content inside the parasitophorous vacuole (PV) in T. gondii-infected SkMC. We also observed a positive modulation of the production of IL-12 and IFN-g, increase of COX-2 mRNA levels in the first hour of T. gondii-SkMC interaction and an increase of prostaglandin E2 (PGE2) synthesis from 6 h up to 48 h of infection. Conclusions Taken together, the close association between SR and LD with PV could represent a source of lipids as well as other nutrients for the parasite survival, and together with the

  5. Small Ubiquitin-like Modifier Alters IFN Response.

    PubMed

    Maarifi, Ghizlane; Maroui, Mohamed Ali; Dutrieux, Jacques; Dianoux, Laurent; Nisole, Sébastien; Chelbi-Alix, Mounira K

    2015-09-01

    IFNs orchestrate immune defense through induction of hundreds of genes. Small ubiquitin-like modifier (SUMO) is involved in various cellular functions, but little is known about its role in IFN responses. Prior work identified STAT1 SUMOylation as an important mode of regulation of IFN-γ signaling. In this study, we investigated the roles of SUMO in IFN signaling, gene expression, protein stability, and IFN-induced biological responses. We first show that SUMO overexpression leads to STAT1 SUMOylation and to a decrease in IFN-induced STAT1 phosphorylation. Interestingly, IFNs exert a negative retrocontrol on their own signaling by enhancing STAT1 SUMOylation. Furthermore, we show that expression of each SUMO paralog inhibits IFN-γ-induced transcription without affecting that of IFN-α. Further, we focused on IFN-induced gene products associated to promyelocytic leukemia (PML) nuclear bodies, and we show that neither IFN-α nor IFN-γ could increase PML and Sp100 protein expression because they enhanced their SUMO3 conjugation and subsequent proteasomal degradation. Because it is known that SUMO3 is important for the recruitment of RING finger protein 4, a poly-SUMO-dependent E3 ubiquitin ligase, and that PML acts as a positive regulator of IFN-induced STAT1 phosphorylation, we went on to show that RING finger protein 4 depletion stabilizes PML and is correlated with a positive regulation of IFN signaling. Importantly, inhibition of IFN signaling by SUMO is associated with a reduction of IFN-induced apoptosis, cell growth inhibition, antiviral defense, and chemotaxis. Conversely, inhibition of SUMOylation results in higher IFN-γ-induced STAT1 phosphorylation and biological responses. Altogether, our results uncover a new role for SUMO in the modulation of IFN response. PMID:26223657

  6. Regulation of the CYP1A1 gene by 2,3,7,8-tetrachlorodibenzo-p-dioxin but not by beta-naphthoflavone or 3-methylcholanthrene is altered in hepatitis C virus replicon-expressing cells.

    PubMed

    Anderson, Garret R; Hasan, Aliya; Yin, Hao; Qadri, Ishtiaq; Quattrochi, Linda C

    2006-09-01

    Exposure to hepatitis C virus (HCV) can lead to the development of cirrhosis and hepatocellular carcinoma. To examine the effects of long-term HCV infection on hepatic cytochrome P450 1A1 (CYP1A1) expression and function, we used a human hepatoma cell line expressing the HCV subgenomic replicon (Huh.8) to evaluate CYP1A1 induction by the aryl hydrocarbon receptor (AhR) ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In this study, we demonstrate that the induction of CYP1A1 expression in Huh.8 cells by TCDD but not by beta-naphthoflavone or 3-methylcholanthrene was significantly diminished. TCDD exposure of Huh.8 cells resulted in greater than 55% suppression of CYP1A1 transcription compared with the parent cell line Huh7, whereas protein levels and enzyme activities were further diminished. Suppression of CYP1A1 mRNA expression in TCDD-treated Huh.8 cells was partially reversed after pretreatment with the antioxidants N-acetylcysteine and nordihydroguaiaretic acid, suggesting a role for oxidative stress. Induced CYP1A1 message, protein, and enzyme activity were partially restored in an Huh7 cell line expressing the HCV replicon containing a deletion in the nonstructural protein NS5A. Furthermore, adenoviral expression of NS5A in Huh7 partially suppressed TCDD-induced CYP1A1 protein and enzyme activity, implicating this protein in the mechanism of suppression. These findings demonstrate that TCDD-mediated AhR signaling is impaired in hepatocytes in which HCV is present and that NS5A alone or in the presence of other nonstructural proteins of the subgenomic replicon is in part responsible. PMID:16788090

  7. Protective effect of Ocimum sanctum on 3-methylcholanthrene, 7,12-dimethylbenz(a)anthracene and aflatoxin B1 induced skin tumorigenesis in mice

    SciTech Connect

    Rastogi, Shipra; Shukla, Yogeshwer; Paul, Bhola N.; Chowdhuri, D. Kar; Khanna, Subhash K.; Das, Mukul

    2007-11-01

    A study on the protective effect of alcoholic extract of the leaves of Ocimum sanctum on 3-mthylcholanthrene (MCA), 7,12-dimethylbenzanthracene (DMBA) and aflatoxin B{sub 1} (AFB{sub 1}) induced skin tumorigenesis in a mouse model has been investigated. The study involved pretreatment of mice with the leaf extract prior to either MCA application or tetradecanoyl phorbol acetate (TPA) treatment in a two-stage tumor protocol viz a viz, DMBA/TPA and AFB1/TPA. The results of the present study indicate that the pretreatment with alcoholic extract of the leaves of O. sanctum decreased the number of tumors in MCA, DMBA/TPA and AFB1/TPA treated mice. The skin tumor induced animals pretreated with alcoholic extract led to a decrease in the expression of cutaneous {gamma}-glutamyl transpeptidase (GGT) and glutathione-S-transferase-P (GST-P) protein. The histopathological examination of skin tumors treated with leaf extract showed increased infiltration of polymorphonuclear, mononuclear and lymphocytic cells, decreased ornithine decarboxylase activity with concomitant enhancement of interleukin-1{beta} (IL-1{beta}) and tumor necrosis factor-{alpha} (TNF-{alpha}) in the serum, implying the in vivo antiproliferative and immunomodulatory activity of leaf extract. The decrease in cutaneous phase I enzymes and elevation of phase II enzymes in response to topical application of leaf extract prior to MCA, AFB1, DMBA/TPA and AFB1/TPA treatment indicate the possibility of impairment in reactive metabolite(s) formation and thereby reducing skin carcinogenicity. Furthermore, pretreatment of leaf extract in the carcinogen induced animals resulted in elevation of glutathione levels and decrease in lipid peroxidation along with heat shock protein expression, indicating a scavenging or antioxidant potential of the extract during chemical carcinogenesis. Thus it can be concluded that leaf extract of O. sanctum provides protection against chemical carcinogenesis in one or more of the

  8. Severe South American Ocular Toxoplasmosis Is Associated with Decreased Ifn-γ/Il-17a and Increased Il-6/Il-13 Intraocular Levels

    PubMed Central

    de-la-Torre, Alejandra; Sauer, Arnaud; Pfaff, Alexander W.; Bourcier, Tristan; Brunet, Julie; Speeg-Schatz, Claude; Ballonzoli, Laurent; Villard, Odile; Ajzenberg, Daniel; Sundar, Natarajan; Grigg, Michael E.

    2013-01-01

    In a cross sectional study, 19 French and 23 Colombian cases of confirmed active ocular toxoplasmosis (OT) were evaluated. The objective was to compare clinical, parasitological and immunological responses and relate them to the infecting strains. A complete ocular examination was performed in each patient. The infecting strain was characterized by genotyping when intraocular Toxoplasma DNA was detectable, as well as by peptide-specific serotyping for each patient. To characterize the immune response, we assessed Toxoplasma protein recognition patterns by intraocular antibodies and the intraocular profile of cytokines, chemokines and growth factors. Significant differences were found for size of active lesions, unilateral macular involvement, unilateral visual impairment, vitreous inflammation, synechiae, and vasculitis, with higher values observed throughout for Colombian patients. Multilocus PCR-DNA sequence genotyping was only successful in three Colombian patients revealing one type I and two atypical strains. The Colombian OT patients possessed heterogeneous atypical serotypes whereas the French were uniformly reactive to type II strain peptides. The protein patterns recognized by intraocular antibodies and the cytokine patterns were strikingly different between the two populations. Intraocular IFN-γ and IL-17 expression was lower, while higher levels of IL-13 and IL-6 were detected in aqueous humor of Colombian patients. Our results are consistent with the hypothesis that South American strains may cause more severe OT due to an inhibition of the protective effect of IFN-γ. PMID:24278490

  9. Oral Administration of EC-12 Increases the Baseline Gene Expression of Antiviral Cytokine Genes, IFN-γ and TNF-α, in Splenocytes and Mesenteric Lymph Node Cells of Weaning Piglets

    PubMed Central

    TSURUTA, Takeshi; INOUE, Ryo; TSUSHIMA, Toshiki; WATANABE, Takumi; TSUKAHARA, Takamitsu; USHIDA, Kazunari

    2013-01-01

    Weaning piglets are continuously exposed to various viruses. The antiviral effects of lactic acid bacteria (LAB) have been confirmed mainly in humans and mice, while few studies have been conducted in livestock. In this study, we evaluated the effect of oral administration of Enterococcus faecalis strain EC-12 (EC-12) on the gene expressions of antiviral cytokines in weaning piglets. Piglets were allocated to the EC-12-administered group (E group) and the no-treatment control group (C group). The small intestinal tissue, the mesenteric lymph node (MLN) cells and the splenocytes were collected from the piglets. The tissue and cells were co-cultured with a live vaccine of porcine reproductive respiratory syndrome virus, porcine epidemic diarrhea virus or EC-12. After the incubation, the gene expressions of IFN-γ and TNF-α in the tissue and cells were evaluated. The gene expressions of IFN-γ in the MLN cells and TNF-α in the splenocytes were significantly higher in the E group than in the C group. However, the increase in the gene expression of antiviral cytokines was observed independently of the antigen treatments. The results of the present study suggest that oral administration of EC-12 did not increase the response of immune cells to specific viral antigens but increased the baseline gene expression of antiviral cytokines. PMID:24936371

  10. Increase in cytokine production (IL-1 beta, IL-6, TNF-alpha but not IFN-gamma, GM-CSF or LIF) by stimulated whole blood cells in postmenopausal osteoporosis.

    PubMed

    Zheng, S X; Vrindts, Y; Lopez, M; De Groote, D; Zangerle, P F; Collette, J; Franchimont, N; Geenen, V; Albert, A; Reginster, J Y

    1997-01-01

    Postmenopausal osteoporosis is a progressive disorder characterized by a decreased bone mass and increased susceptibility to fractures. Several investigations have suggested that one of the mechanisms through which estrogen prevents bone loss was a modulation on secretion or release of various cytokines that are known to influence bone remodeling, even if some recent data have challenged this hypothesis. However, in established osteoporosis, the possibility that enhanced cytokines activity may account for the progression of this disease remains unclear and controversial. We sought here to determine whether production of IL-1 beta, IL-6, TNF-alpha, IFN-gamma, GM-CSF and LIF, after direct stimulation in whole blood, was different in healthy (n = 30) or osteoporotic postmenopausal women (n = 24) and whether lumbar bone density (1-BMD) correlated with the values of cytokine production observed in these conditions. A significant difference was observed between the osteoporotic and control subjects for IL-1 beta (p < 0.0001), IL-6 (p < 0.001) and TNF-alpha (p = 0.027) productions, the values being higher in the osteoporotic women. No significant differences between the groups were observed for IFN-gamma (p = 0.51), GM-CSF (p = 0.70) or LIF (p = 0.97). In the whole population, statistically significant negative correlations were observed between lumbar BMD and IL-1 beta (r = -0.46) (p < 0.0005), IL-6 (r = -0.50) (p < 0.0001) and TNF-alpha (r = -0.39) (p < 0.005) production while no such correlations were observed for IFN-gamma, GM-CSF or LIF. In conclusion, the study of cytokine production by immune cells cultured in autologous whole blood suggests that in women more than 10 years past the menopause and presenting a decrease in lumbar bone density corresponding to the new WHO definition of "osteoporosis', production of IL-1 beta, IL-6 and TNF-alpha is still increased compared to controls matched for age and ovarian function, while no differences are reported for IFN

  11. Ribavirin Improves the IFN-γ Response of Natural Killer Cells to IFN-based Therapy of Hepatitis C Virus Infection

    PubMed Central

    Werner, Jens M.; Serti, Elisavet; Chepa-Lotrea, Xenia; Stoltzfus, Jonathan; Ahlenstiel, Golo; Noureddin, Mazen; Feld, Jordan J.; Liang, T. Jake; Rotman, Yaron; Rehermann, Barbara

    2015-01-01

    Ribavirin is an important component of interferon-based and direct antiviral treatment regimens for hepatitis C virus (HCV) infection. Immunomodulation, in particular improvement of the host interferon (IFN) response, has been proposed as ribavirin’s mechanism of action. Natural killer (NK) cells are sensitive biomarkers for IFN-α/β receptor signaling, as NK cell cytotoxicity and IFN-γ production are regulated by STAT1- and STAT4-phosphorylation, respectively. Specifically, pSTAT1-dependent NK cell cytotoxicity increases and pSTAT4-dependent IFN-γ production decreases in response to endogenous, virus-induced IFN-α and during IFN-α-based therapy. To assess whether ribavirin has a direct effect on NK cells and/or improves the IFN-γ response of NK cells in the presence of IFN-α, we prospectively studied 22 HCV patients with and 32 patients without 4 weeks of ribavirin pretreatment, who all received subsequent PegIFN/ribavirin combination therapy. During ribavirin pretreatment, the frequency of CD56dim NK cells with cytotoxic effector functions decreased (p=0.049) as did the frequency of CD56bright NK cells with the capacity to produce IFN-γ (p=0.001). In vitro or in vivo exposure of NK cells to ribavirin improved the pSTAT4 (p<0.01) but not pSTAT1 response of NK cells to subsequent stimulation with IFN-α. This was associated with an increase in IFN-γ production but not cytotoxicity of NK cells during subsequent IFN-α-based therapy. The frequency of IFN-γ-producing NK cells was greater in fast second-phase virological responders than in slow responders. Conclusion Ribavirin enhances the pSTAT4 and IFN-γ response of NK cells to IFN-α–stimulation. PMID:24700342

  12. Endogenous intrahepatic IFNs and association with IFN-free HCV treatment outcome

    PubMed Central

    Meissner, Eric G.; Wu, David; Osinusi, Anu; Bon, Dimitra; Virtaneva, Kimmo; Sturdevant, Dan; Porcella, Steve; Wang, Honghui; Herrmann, Eva; McHutchison, John; Suffredini, Anthony F.; Polis, Michael; Hewitt, Stephen; Prokunina-Olsson, Ludmila; Masur, Henry; Fauci, Anthony S.; Kottilil, Shyamasundaran

    2014-01-01

    BACKGROUND. Hepatitis C virus (HCV) infects approximately 170 million people worldwide and may lead to cirrhosis and hepatocellular carcinoma in chronically infected individuals. Treatment is rapidly evolving from IFN-α–based therapies to IFN-α–free regimens that consist of directly acting antiviral agents (DAAs), which demonstrate improved efficacy and tolerability in clinical trials. Virologic relapse after DAA therapy is a common cause of treatment failure; however, it is not clear why relapse occurs or whether certain individuals are more prone to recurrent viremia. METHODS. We conducted a clinical trial using the DAA sofosbuvir plus ribavirin (SOF/RBV) and performed detailed mRNA expression analysis in liver and peripheral blood from patients who achieved either a sustained virologic response (SVR) or relapsed. RESULTS. On-treatment viral clearance was accompanied by rapid downregulation of IFN-stimulated genes (ISGs) in liver and blood, regardless of treatment outcome. Analysis of paired pretreatment and end of treatment (EOT) liver biopsies from SVR patients showed that viral clearance was accompanied by decreased expression of type II and III IFNs, but unexpectedly increased expression of the type I IFN IFNA2. mRNA expression of ISGs was higher in EOT liver biopsies of patients who achieved SVR than in patients who later relapsed. CONCLUSION. These results suggest that restoration of type I intrahepatic IFN signaling by EOT may facilitate HCV eradication and prevention of relapse upon withdrawal of SOF/RBV. TRIAL REGISTRATION. ClinicalTrials.gov NCT01441180. FUNDING. Intramural Programs of the National Institute of Allergy and Infectious Diseases, National Institutes of Health Clinical Center, and National Cancer Institute; German Research Foundation. PMID:24983321

  13. Absence of IFNincreases brain pathology in experimental autoimmune encephalomyelitis-susceptible DRB1*0301.DQ8 HLA transgenic mice through secretion of proinflammatory cytokine IL-17 and induction of pathogenic monocytes/microglia into the central nervous system.

    PubMed

    Mangalam, Ashutosh K; Luo, Ningling; Luckey, David; Papke, Louisa; Hubbard, Alyssa; Wussow, Arika; Smart, Michele; Giri, Shailendra; Rodriguez, Moses; David, Chella

    2014-11-15

    Multiple sclerosis is an inflammatory, demyelinating disease of the CNS of presumed autoimmune origin. Of all the genetic factors linked with multiple sclerosis, MHC class II molecules have the strongest association. Generation of HLA class II transgenic (Tg) mice has helped to elucidate the role of HLA class II genes in chronic inflammatory and demyelinating diseases. We have shown that the human HLA-DRB1*0301 gene predisposes to proteolipid protein (PLP)-induced experimental autoimmune encephalomyelitis (EAE), whereas HLA-DQβ1*0601 (DQ6) was resistant. We also showed that the DQ6 molecule protects from EAE in DRB1*0301.DQ6 double-Tg mice by producing anti-inflammatory IFN-γ. HLA-DQβ1*0302 (DQ8) Tg mice were also resistant to PLP(91-110)-induced EAE, but production of proinflammatory IL-17 exacerbated disease in DRB1*0301.DQ8 mice. To further confirm the role of IFN-γ in protection, we generated DRB1*0301.DQ8 mice lacking IFN-γ (DRB1*0301.DQ8.IFN-γ(-/-)). Immunization with PLP(91-110) peptide caused atypical EAE in DRB1*0301.DQ8.IFN-γ(-/-) mice characterized by ataxia, spasticity, and dystonia, hallmarks of brain-specific disease. Severe brain-specific inflammation and demyelination in DRB1*0301.DQ8.IFN-γ(-/-) mice with minimal spinal cord pathology further confirmed brain-specific pathology. Atypical EAE in DRB1*0301.DQ8.IFN-γ(-/-) mice was associated with increased encephalitogenicity of CD4 T cells and their ability to produce greater levels of IL-17 and GM-CSF compared with DRB1*0301.DQ8 mice. Further, areas with demyelination showed increased presence of CD68(+) inflammatory cells, suggesting an important role for monocytes/microglia in causing brain pathology. Thus, our study supports a protective role for IFN-γ in the demyelination of brain through downregulation of IL-17/GM-CSF and induction of neuroprotective factors in the brain by monocytes/microglial cells. PMID:25339670

  14. TBX21-1993T/C (rs4794067) polymorphism is associated with increased risk of chronic periodontitis and increased T-bet expression in periodontal lesions, but does not significantly impact the IFN-g transcriptional level or the pattern of periodontophatic bacterial infection

    PubMed Central

    Cavalla, Franco; Biguetti, Claudia Cristina; Colavite, Priscila Maria; Silveira, Elcia Varise; Martins, Walter; Letra, Ariadne; Trombone, Ana Paula Favaro; Silva, Renato Menezes; Garlet, Gustavo Pompermaier

    2015-01-01

    Th1-polarized host response, mediated by IFN-γ, has been associated with increased severity of periodontal disease as well as control of periodontal infection. The functional polymorphism TBX21-1993T/C (rs4794067) increases the transcriptional activity of the TBX21 gene (essential for Th1 polarization) resulting in a predisposition to a Th-1 biased immune response. Thus, we conducted a case-control study, including a population of healthy controls (H, n = 218), chronic periodontitis (CP, n = 197), and chronic gingivitis patients (CG, n = 193), to investigate if genetic variations in TBX21 could impact the development of Th1 responses, and consequently influence the pattern of bacterial infection and periodontitis outcome. We observed that the polymorphic allele T was significantly enriched in the CP patients compared to CG subjects, while the H controls demonstrated and intermediate genotype. Also, investigating the putative functionality TBX21-1993T/C in the modulation of local response, we observed that the transcripts levels of T-bet, but not of IFN-γ, were upregulated in homozygote and heterozygote polymorphic subjects. In addition, TBX21-1993T/C did not influence the pattern of bacterial infection or the clinical parameters of disease severity, being the presence/absence of red complex bacteria the main factor associated with the disease status and the subrogate variable probing depth (PD) in the logistic regression analysis. PMID:25832120

  15. IFN-γ ameliorates autoimmune encephalomyelitis by limiting myelin lipid peroxidation

    PubMed Central

    Sosa, Rebecca A.; Murphey, Cathi; Robinson, Rachel R.; Forsthuber, Thomas G.

    2015-01-01

    Evidence has suggested both a pathogenic and a protective role for the proinflammatory cytokine IFN-γ in experimental autoimmune encephalomyelitis (EAE). However, the mechanisms underlying the protective role of IFN-γ in EAE have not been fully resolved, particularly in the context of CNS antigen-presenting cells (APCs). In this study we examined the role of IFN-γ in myelin antigen uptake by CNS APCs during EAE. We found that myelin antigen colocalization with APCs was decreased substantially and that EAE was significantly more severe and showed a chronic-progressive course in IFN-γ knockout (IFN-γ−/−) or IFN-γ receptor knockout (IFN-γR−/−) mice as compared with WT animals. IFN-γ was a critical regulator of phagocytic/activating receptors on CNS APCs. Importantly, “free” myelin debris and lipid peroxidation activity at CNS lesions was increased in mice lacking IFN-γ signaling. Treatment with N-acetyl-l-cysteine, a potent antioxidant, abolished lipid peroxidation activity and ameliorated EAE in IFN-γ–signaling-deficient mice. Taken together the data suggest a protective role for IFN-γ in EAE by regulating the removal of myelin debris by CNS APCs and thereby limiting the substrate available for the generation of neurotoxic lipid peroxidation products. PMID:26305941

  16. IFN-gamma AU-rich element removal promotes chronic IFN-gamma expression and autoimmunity in mice

    PubMed Central

    Hodge, Deborah L.; Berthet, Cyril; Coppola, Vincenzo; Kastenmüller, Wolfgang; Buschman, Matthew D.; Schaughency, Paul M.; Shirota, Hidekazu; Scarzello, Anthony J.; Subleski, Jeff J.; Anver, Miriam R.; Ortaldo, John R.; Lin, Fanching; Reynolds, Della A.; Sanford, Michael E.; Kaldis, Philipp; Tessarollo, Lino; Klinman, Dennis M.; Young, Howard A.

    2014-01-01

    We generated a mouse model with a 162 nt AU-rich element (ARE) region deletion in the 3′ untranslated region (3′UTR) of the interferon-gamma (IFN-γ) gene that results in chronic circulating serum IFN-γ levels. Mice homozygous for the ARE deletion (ARE-Del) −/− present both serologic and cellular abnormalities typical of patients with systemic lupus erythematosus (SLE). ARE-Del−/− mice display increased numbers of pDCs in bone marrow and spleen. Addition of IFN-γ to Flt3-ligand (Flt3L) treated in vitro bone marrow cultures results in a 2-fold increase in pDCs with concurrent increases in IRF8 expression. Marginal zone B (MZB) cells and marginal zone macrophages (MZMs) are absent in ARE-Del−/− mice. ARE-Del+/− mice retain both MZB cells and MZMs and develop no or mild autoimmunity. However, low dose clodronate treatment in ARE-Del+/− mice specifically eliminates MZMs and promotes anti-DNA antibody development and glomerulonephritis. Our findings demonstrate the consequences of a chronic IFN-γ milieu on B220+ cell types and in particular the impact of MZB cell loss on MZM function in autoimmunity. Furthermore, similarities between disease states in ARE-Del−/− mice and SLE patients suggest that IFN-γ may not only be a product of SLE but may be critical for disease onset and progression. PMID:24583068

  17. Influenza A/Hong Kong/156/1997(H5N1) virus NS1 gene mutations F103L and M106I both increase IFN antagonism, virulence and cytoplasmic localization but differ in binding to RIG-I and CPSF30

    PubMed Central

    2013-01-01

    Background The genetic basis for avian to mammalian host switching in influenza A virus is largely unknown. The human A/HK/156/1997 (H5N1) virus that transmitted from poultry possesses NS1 gene mutations F103L + M106I that are virulence determinants in the mouse model of pneumonia; however their individual roles have not been determined. The emergent A/Shanghai/patient1/2013(H7N9)-like viruses also possess these mutations which may contribute to their virulence and ability to switch species. Methods NS1 mutant viruses were constructed by reverse genetics and site directed mutagenesis on human and mouse-adapted backbones. Mouse infections assessed virulence, virus yield, tissue infection, and IFN induction. NS1 protein properties were assessed for subcellular distribution, IFN antagonism (mouse and human), CPSF30 and RIG-I domain binding, host transcription (microarray); and the natural prevalence of 103L and 106I mutants was assessed. Results Each of the F103L and M106I mutations contributes additively to virulence to reduce the lethal dose by >800 and >3,200 fold respectively by mediating alveolar tissue infection with >100 fold increased infectious yields. The 106I NS1 mutant lost CPSF binding but the 103L mutant maintained binding that correlated with an increased general decrease in host gene expression in human but not mouse cells. Each mutation positively modulated the inhibition of IFN induction in mouse cells and activation of the IFN-β promoter in human cells but not in combination in human cells indicating negative epistasis. Each of the F103L and M106I mutations restored a defect in cytoplasmic localization of H5N1 NS1 in mouse cells. Human H1N1 and H3N2 NS1 proteins bound to the CARD, helicase and RD RIG-I domains, whereas the H5N1 NS1 with the same consensus 103F and 106M mutations did not bind these domains, which was totally or partially restored by the M106I or F103L mutations respectively. Conclusions The F103L and M106I mutations in the H5N1 NS1

  18. Type I IFN Does Not Promote Susceptibility to Foodborne Listeria monocytogenes.

    PubMed

    Pitts, Michelle G; Myers-Morales, Tanya; D'Orazio, Sarah E F

    2016-04-01

    Type I IFN (IFN-α/β) is thought to enhance growth of the foodborne intracellular pathogen Listeria monocytogenes by promoting mechanisms that dampen innate immunity to infection. However, the type I IFN response has been studied primarily using methods that bypass the stomach and, therefore, fail to replicate the natural course of L. monocytogenes infection. In this study, we compared i.v. and foodborne transmission of L. monocytogenes in mice lacking the common type I IFN receptor (IFNAR1(-/-)). Contrary to what was observed using i.v. infection, IFNAR1(-/-) and wild-type mice had similar bacterial burdens in the liver and spleen following foodborne infection. Splenocytes from wild-type mice infected i.v. produced significantly more IFN-β than did those infected by the foodborne route. Consequently, the immunosuppressive effects of type I IFN signaling, which included T cell death, increased IL-10 secretion, and repression of neutrophil recruitment to the spleen, were all observed following i.v. but not foodborne transmission of L. monocytogenes. Type I IFN was also previously shown to cause a loss of responsiveness to IFN-γ through downregulation of the IFN-γ receptor α-chain on macrophages and dendritic cells. However, we detected a decrease in surface expression of IFN-γ receptor α-chain even in the absence of IFN-α/β signaling, suggesting that in vivo, this infection-induced phenotype is not type I IFN-dependent. These results highlight the importance of using the natural route of infection for studies of host-pathogen interactions and suggest that the detrimental effects of IFN-α/β signaling on the innate immune response to L. monocytogenes may be an artifact of the i.v. infection model. PMID:26895837

  19. Interaction of IFN-γ with Cholinergic Agonists to Modulate Rat and Human Goblet Cell Function

    PubMed Central

    García-Posadas, L; Hodges, RR; Li, D; Shatos, MA; Storr-Paulsen, T; Diebold, Y; Dartt, DA

    2015-01-01

    Goblet cells populate wet-surfaced mucosa including the conjunctiva of the eye, intestine, and nose, among others. These cells function as part of the innate immune system by secreting high molecular weight mucins that interact with environmental constituents including pathogens, allergens, and particulate pollutants. Herein we determined whether IFN-γ, a Th1 cytokine increased in dry eye, alters goblet cell function. Goblet cells from rat and human conjunctiva were cultured. Changes in intracellular [Ca2+] ([Ca2+]i), high molecular weight glycoconjugate secretion, and proliferation were measured after stimulation with IFN-γ with or without the cholinergic agonist carbachol. IFN-γ itself increased [Ca2+]i in rat and human goblet cells and prevented the increase in [Ca2+]i caused by carbachol. Carbachol prevented IFN-γ-mediated increase in [Ca2+]i. This cross-talk between IFN-γ and muscarinic receptors may be partially due to use of the same Ca2+i reservoirs, but also from interaction of signaling pathways proximal to the increase in [Ca2+]i. IFN-γ blocked carbachol-induced high molecular weight glycoconjugate secretion and reduced goblet cell proliferation. We conclude that increased levels of IFN-γ in dry eye disease could explain the lack of goblet cells and mucin deficiency typically found in this pathology. IFN-γ could also function similarly in respiratory and gastrointestinal tracts. PMID:26129651

  20. Identification of an IFN-gamma-producing neutrophil early in the response to Listeria monocytogenes.

    PubMed

    Yin, Jiyi; Ferguson, Thomas A

    2009-06-01

    IFN-gamma plays a critical role during the immune response to infection with Listeria monocytogenes. Early in the innate response NK cells are thought to be a primary source of IFN-gamma; however, protection can be mediated by the presence of significant numbers of primed IFN-gamma-secreting CD8(+) T cells. In this report, we examined the early response to Listeria and found that 18 h after infection spleens contain CD11b(+), Gr-1(high), or Ly6G(+) cells that produce significant IFN-gamma. Morphological analysis of sorted Gr-1(high)IFN-gamma(+) and Gr-1(low)IFN-gamma(+) or Ly6G(+)IFN-gamma(+) cells confirmed that these cells were neutrophils. The importance of IFN-gamma production by these cells was further tested using adoptive transfer studies. Transfer of purified neutrophils from Ifng(+/+) mice led to increased bacterial clearance in Ifng(-/-) mice. Transfer of Ifng(-/-) neutrophils provided no such protection. We conclude that neutrophils are an early source of IFN-gamma during Listeria infection and are important in providing immune protection. PMID:19454704

  1. Regulation of IFN regulatory factor-7 and IFN-alpha production by enveloped virus and lipopolysaccharide in human plasmacytoid dendritic cells.

    PubMed

    Dai, Jihong; Megjugorac, Nicholas J; Amrute, Sheela B; Fitzgerald-Bocarsly, Patricia

    2004-08-01

    Human plasmacytoid dendritic cells (PDC) are a major source of IFN-alpha upon exposure to enveloped viruses and TLR-7 and TLR-9 ligands. Although IFN regulatory factor-7 (IRF-7) is known to play an essential role in virus-activated transcription of IFN-alpha genes, the molecular mechanisms of IFN-alpha production in human PDC remain poorly understood. We and others have recently reported high constitutive levels of IRF-7 expression in PDC as compared with other PBMC. In this study, we demonstrate that both LPS and HSV up-regulate the expression of IRF-7 in PDC, and that this enhancement of IRF-7 is dependent on NF-kappa B activation. The NF-kappa B inhibitors MG132 and pyrrolidinedithiocarbamate efficiently inhibited the induction of IRF-7 by HSV or LPS, and also down-regulated the constitutive expression of IRF-7 in PDC and blocked the HSV-induced production of IFN-alpha. In addition, we found that nuclear translocation of IRF-7 occurred rapidly in response to HSV stimulation, but not in response to LPS, which is consistent with the stimulation of IFN-alpha production by virus and not by LPS. Although LPS by itself was not able to induce IFN-alpha production, it led to rapid up-regulation of TLR-4 on PDC and increased the magnitude and accelerated the kinetics of HSV-induced IFN-alpha production in PDC, providing a mechanism that might be operative in a scenario of mixed infection. In contrast to the current concept of IFN-alpha regulation established in cell lines, this study strongly supports the immediate availability of high constitutive levels of IRF-7 expression in PDC, and suggests an activation required for IRF-7 that contributes to IFN-alpha production in virus-stimulated PDC. PMID:15265881

  2. Identification of IFN-γ-producing innate B cells

    PubMed Central

    Bao, Yan; Liu, Xingguang; Han, Chaofeng; Xu, Sheng; Xie, Bin; Zhang, Qian; Gu, Yan; Hou, Jin; Qian, Li; Qian, Cheng; Han, Huanxing; Cao, Xuetao

    2014-01-01

    Although B cells play important roles in the humoral immune response and the regulation of adaptive immunity, B cell subpopulations with unique phenotypes, particularly those with non-classical immune functions, should be further investigated. By challenging mice with Listeria monocytogenes, Escherichia coli, vesicular stomatitis virus and Toll-like receptor ligands, we identified an inducible CD11ahiFcγRIIIhi B cell subpopulation that is significantly expanded and produces high levels of IFN-γ during the early stage of the immune response. This subpopulation of B cells can promote macrophage activation via generating IFN-γ, thereby facilitating the innate immune response against intracellular bacterial infection. As this new subpopulation is of B cell origin and exhibits the phenotypic characteristics of B cells, we designated these cells as IFN-γ-producing innate B cells. Dendritic cells were essential for the inducible generation of these innate B cells from the follicular B cells via CD40L-CD40 ligation. Increased Bruton's tyrosine kinase activation was found to be responsible for the increased activation of non-canonical NF-κB pathway in these innate B cells after CD40 ligation, with the consequent induction of additional IFN-γ production. The identification of this new population of innate B cells may contribute to a better understanding of B cell functions in anti-infection immune responses and immune regulation. PMID:24296781

  3. The antiviral effects of acteoside and the underlying IFN-γ-inducing action.

    PubMed

    Song, Xun; He, Jiang; Xu, Hong; Hu, Xiao-Peng; Wu, Xu-Li; Wu, Hai-Qiang; Liu, Li-Zhong; Liao, Cheng-Hui; Zeng, Yong; Li, Yan; Hao, Yue; Xu, Chen-Shu; Fan, Long; Zhang, Jian; Zhang, Hong-Jie; He, Zhen-Dan

    2016-07-13

    There are many herbal teas that are found in nature that may be effective at treating the symptoms and also shortening the duration of viral infections. When combating viral infections, T lymphocytes are an indispensable part of human acquired immunity. However, studies on the use of natural products in stimulating lymphocyte-mediated interferon-gamma (IFN-γ) production are very limited. In this study, we found that acteoside, a natural phenylpropanoid glycoside from Kuding Tea, enhanced IFN-γ production in mouse lymphocytes in a dose-dependent manner, particularly in the CD4+ and CD8+ subsets of T lymphocytes. To this end, we suggest that the antiviral activity of acteoside was highly correlated to its inducing ability of IFN-γ production. Mechanistically, the activation of T-bet enhanced the promoter of IFN-γ and subsequently resulted in an increased IFN-γ production in T cells. Collectively, we have found a natural product with the capacity to selectively enhance mouse T cell IFN-γ production. Given the role of IFN-γ in the immune system, further studies to clarify the role of acteoside in inducing IFN-γ and prevention of viral infection are needed. PMID:27326537

  4. Stimulator of IFN Gene Is Critical for Induction of IFN-β during Chlamydia muridarum Infection

    PubMed Central

    Prantner, Daniel; Darville, Toni; Nagarajan, Uma M.

    2010-01-01

    Type I IFN signaling has recently been shown to be detrimental to the host during infection with Chlamydia muridarum in both mouse lung and female genital tract. However, the pattern recognition receptor and the signaling pathways involved in chlamydial-induced IFN-β are unclear. Previous studies have demonstrated no role for TLR4 and a partial role for MyD88 in chlamydial-induced IFN-β. In this study, we demonstrate that mouse macrophages lacking TLR3, TRIF, TLR7, or TLR9 individually or both TLR4 and MyD88, still induce IFN-β equivalent to wild type controls, leading to the hypothesis that TLR-independent cytosolic pathogen receptor pathways are crucial for this response. Silencing nucleotide-binding oligomerization domain 1 in HeLa cells partially decreased chlamydial-induced IFN-β. Independently, small interfering RNA-mediated knockdown of the stimulator of IFN gene (STING) protein in HeLa cells and mouse oviduct epithelial cells significantly decreased IFN-β mRNA expression, suggesting a critical role for STING in chlamydial-induced IFN-β induction. Conversely, silencing of mitochondria-associated antiviral signaling proteins and the Rig-I–like receptors, RIG-I, and melanoma differentiation associated protein 5, had no effect. In addition, induction of IFN-β depended on the downstream transcription IFN regulatory factor 3, and on activation of NF-κB and MAPK p38. Finally, STING, an endoplasmic reticulum-resident protein, was found to localize in close proximity to the chlamydial inclusion membrane during infection. These results indicate that C. muridarum induces IFN-β via stimulation of nucleotide-binding oligomerization domain 1 pathway, and TLR- and Rig-I–like receptor-independent pathways that require STING, culminating in activation of IFN regulatory factor 3, NF-κB, and p38 MAPK. PMID:20107183

  5. IFN-α Induces Transcription of Hypoxia-Inducible Factor-1α to Inhibit Proliferation of Human Endothelial Cells1

    PubMed Central

    Gerber, Scott A.; Pober, Jordan S.

    2009-01-01

    Expression of hypoxia-inducible factor (HIF)-1α, a transcription factor subunit increased by protein stabilization in response to hypoxia, is increased in human endothelial cells (ECs) by IFN-α under normoxic conditions. IFNincreases HIF-1α transcript levels within 2 h by up to 50% and doubles HIF-1α protein expression. Based on pharmacological inhibition studies, the increase in HIF-1α mRNA involves new transcription, is independent of new protein synthesis, and requires JAK signaling. Protein knockdown by small interfering RNA confirms the involvement of JAK1 and TYK2, as well of IFN-stimulated gene factor 3 (ISGF3). IFN-γ does not significantly induce HIF-1α mRNA, but increases the magnitude and duration of the IFN-α effect. IFN-α-induced HIF-1α protein translocates to the nucleus and can bind to hypoxia response elements in DNA. However, IFN-α treatment fails to induce transcription of several prototypic HIF-responsive genes (VEGF-A, PPARγ, and prostacyclin synthase) due to an insufficient increase in HIF-1α protein levels. Although certain other HIF-responsive genes (PHD3 and VEGF-C) are induced following IFN-α and/or IFN-γ treatment, these responses are not inhibited by siRNA knockdown of HIF-1α. Additionally, IFN-α induction of ISGF3-dependent genes involved in innate immunity (viperin, OAS2, and CXCL10) are also unaffected by knockdown of HIF-1α. Interestingly, knockdown of HIF-1α significantly reduces the capacity of IFN-α to inhibit endothelial cell proliferation. We conclude that IFN-α induces the transcription of HIF-1α in human endothelial cells though a JAK-ISGF3 pathway under normoxic conditions, and that this response contributes to the antiproliferative activity of this cytokine. PMID:18606657

  6. Protective efficacy of IFN-ω AND IFN-λs against influenza viruses in induced A549 cells.

    PubMed

    Škorvanová, L; Švančarová, P; Svetlíková, D; Betáková, T

    2015-12-01

    The interferon system represents one of the components of the first line defence against influenza virus infection. Interferon omega (IFN-ω) is antigenetically different from IFN-α and IFN-β and can affect patients who are resistant to these IFNs. To improve the biological characterization of IFN-ω, we compared its activity with those of type I and type III IFNs in induced A549 cells. The antiviral effect on IFN-stimulated A549 cells was most apparent after infection with avian influenza virus. IFN-ω had statistically significant antiviral activity although less than IFN-β1a, IFN-λ1, or IFN-λ2. On the other hand, IFN-ω appeared more efficient than IFN-α2. Our results also indicate that IFN-λs were more suitable against human highly pathogenic virus. In this case, IFN-λ1 and IFN-λ2 were more potent than type I IFNs. PMID:26666190

  7. Curcumin modulation of IFN-β and IL-12 signalling and cytokine induction in human T cells

    PubMed Central

    Fahey, Angela J; Adrian Robins, R; Constantinescu, Cris S

    2007-01-01

    Abstract Curcumin is a polyphenol derived from the dietary spice turmeric. It possesses diverse anti-inflammatory and anti-cancer properties. Curcumin has been shown to exhibit an inhibitory effect on the production of inflammatory cytokines by human monocytes and has inhibited the animal model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE) in association with a decrease in interleukin 12 (IL-12) production and signal transducer and activator of transcription 4 (STAT4) activation. The type I interferon (IFN) IFN-has the ability to suppress IL-12. Both IL-12 and IFN-α/β signal through the activation by phosphorylation of STAT4. Our aim was to investigate the effects of curcumin on the ability of T cells to respond to IL-12 or IFN-α/β. We report that curcumin decreases IL-12-induced STAT4 phosphorylation, IFN-γ production, and IL-12 Rβ1 and β2 expression. IFN-β-induced STAT4 phosphorylation, IL-10 production and IFN receptor (IFNAR) subunits 1 and 2 expression were enhanced by curcumin. Curcumin increased IFN-α-induced IL-10 and IFNAR1 expression. Prior exposure to curcumin decreased IFN-α-induced IFNAR2 expression and did not modify the level of IFN-α-induced pSTAT4 generation. Thus, the effect of curcumin on STAT4 activation in T cells is dependent upon the stimulus to which the T cells have been exposed. PMID:17979888

  8. Murine gammaherpesvirus targets type I IFN receptor but not type III IFN receptor early in infection.

    PubMed

    Lopušná, Katarína; Benkóczka, Tímea; Lupták, Jakub; Matúšková, Radka; Lukáčiková, Ľubomíra; Ovečková, Ingrid; Režuchová, Ingeborg

    2016-07-01

    The innate immune response represents a primary line of defense against invading viral pathogens. Since epithelial cells are the primary site of gammaherpesvirus replication during infection in vivo and there are no information on activity of IFN-III signaling against gammaherpesviruses in this cell type, in present study, we evaluated the expression profile and virus-host interactions in mouse mammary epithelial cell (NMuMG) infected with three strains of murine gammaherpesvirus, MHV-68, MHV-72 and MHV-4556. Studying three strains of murine gammaherpesvirus, which differ in nucleotide sequence of some structural and non-structural genes, allowed us to compare the strain-dependent interactions with host organism. Our results clearly demonstrate that: (i) MHV-68, MHV-72 and MHV-4556 differentially interact with intracellular signaling and dysregulate IFN signal transduction; (ii) MHV-68, MHV-72 and MHV-4556 degrade type I IFN receptor in very early stages of infection (2-4hpi), but not type III IFN receptor; (iii) type III IFN signaling might play a key role in antiviral defense of epithelial cells in early stages of murine gammaherpesvirus replication; (iv) NMuMG cells are an appropriate model for study of not only type I IFN signaling, but also type III IFN signaling pathway. These findings are important for better understanding of individual virus-host interactions in lytic as well as in persistent gammaherpesvirus replication and help us to elucidate IFN-III function in early events of virus infection. PMID:27152708

  9. IFN-λ cancer immunotherapy: new kid on the block.

    PubMed

    Lasfar, Ahmed; Gogas, Helen; Zloza, Andrew; Kaufman, Howard L; Kirkwood, John M

    2016-07-01

    Interferon-lambda (IFN-λ) is a new IFN type, related to IFN-α, that is commonly used in the clinic. However, significant side effects accompanying IFN-α treatment limit enthusiasm for IFN-α. In this review, we discuss the current landscape of IFN-α use in oncology and describe the biologic characteristics of IFN-λ. IFN-λ offers unique advantages, including a more tumor cell selective targeting, lower off-target binding and an ability to generate both innate and adaptive immune responses. IFN-λ has also demonstrated therapeutic benefit in murine cancer models. IFN-λ may be used in clinic as a single agent or in combination with other immunotherapy agents, such as immune checkpoint inhibitors. Further clinical trials will be needed to fully elucidate the potential of this novel agent in oncology. PMID:27381684

  10. IL-13-mediated worm expulsion is B7 independent and IFN-gamma sensitive.

    PubMed

    Urban, J; Fang, H; Liu, Q; Ekkens, M J; Chen, S J; Nguyen, D; Mitro, V; Donaldson, D D; Byrd, C; Peach, R; Morris, S C; Finkelman, F D; Schopf, L; Gause, W C

    2000-04-15

    B7 costimulation is a required component of many type 2 immune responses, including allergy and protective immunity to many nematode parasites. This response includes elevations in Th2 cytokines and associated effector functions including elevations in serum IgG1 and IgE and parasite expulsion. In studies of mice infected with Trichuris muris, blocking B7 ligand interactions inhibited protective immunity, suppressed IL-4 production, and enhanced IFN-gamma production, but unexpectedly did not inhibit production of the Th2 cytokine, IL-13. Blocking both IFN-gamma and B7 restored protective immunity, which was IL-13 dependent, but did not restore IL-4 or associated IgE responses. Although IL-13 was required for worm expulsion in mice in which both IFN-gamma and B7 were blocked, IL-4 could mediate expulsion in the absence of both IL-13 and IFN-gamma. These studies demonstrate that 1) B7 costimulation is required to induce IL-4, but not IL-13 responses; 2) IL-13 is elevated in association with the IFN-gamma response that occurs following inhibition of B7 interactions, but can only mediate IL-4-independent protection when IFN-gamma is also inhibited; and 3) increased IL-13 production, in the absence of increased IL-4 production, is not associated with an IgE response, even in the absence of IFN-gamma. PMID:10754322

  11. HIF-1α Is an Essential Mediator of IFN-γ-Dependent Immunity to Mycobacterium tuberculosis.

    PubMed

    Braverman, Jonathan; Sogi, Kimberly M; Benjamin, Daniel; Nomura, Daniel K; Stanley, Sarah A

    2016-08-15

    The cytokine IFN-γ coordinates macrophage activation and is essential for control of pathogens, including Mycobacterium tuberculosis However, the mechanisms by which IFN-γ controls M. tuberculosis infection are only partially understood. In this study, we show that the transcription factor hypoxia-inducible factor-1α (HIF-1α) is an essential mediator of IFN-γ-dependent control of M. tuberculosis infection both in vitro and in vivo. M. tuberculosis infection of IFN-γ-activated macrophages results in a synergistic increase in HIF-1α protein levels. This increase in HIF-1α levels is functionally important, as macrophages lacking HIF-1α are defective for IFN-γ-dependent control of infection. RNA-sequencing demonstrates that HIF-1α regulates nearly one-half of all IFN-γ-inducible genes during infection of macrophages. In particular, HIF-1α regulates production of important immune effectors, including inflammatory cytokines and chemokines, eicosanoids, and NO. In addition, we find that during infection HIF-1α coordinates a metabolic shift to aerobic glycolysis in IFN-γ-activated macrophages. We find that this enhanced glycolytic flux is crucial for IFN-γ-dependent control of infection in macrophages. Furthermore, we identify a positive feedback loop between HIF-1α and aerobic glycolysis that amplifies macrophage activation. Finally, we demonstrate that HIF-1α is crucial for control of infection in vivo as mice lacking HIF-1α in the myeloid lineage are strikingly susceptible to infection and exhibit defective production of inflammatory cytokines and microbicidal effectors. In conclusion, we have identified HIF-1α as a novel regulator of IFN-γ-dependent immunity that coordinates an immunometabolic program essential for control of M. tuberculosis infection in vitro and in vivo. PMID:27430718

  12. Microglia activation is associated with IFN-α induced depressive-like behavior.

    PubMed

    Wachholz, Simone; Eßlinger, Manuela; Plümper, Jennifer; Manitz, Marie-Pierre; Juckel, Georg; Friebe, Astrid

    2016-07-01

    Inflammatory immune activation has been frequently associated with the development of major depression. This association was confirmed in patients receiving long-term treatment with pro-inflammatory interferon-α (IFN-α). Microglia, the resident immune cells in the brain, might serve as an important interface in this immune system-to-brain communication. The aim of the present study was to investigate the role of microglia in an IFN-α mouse model of immune-mediated depression. Male BALB/c mice were treated with daily injections of IFN-α for two weeks. Depressive-like behavior was analyzed in the forced swim and tail suspension test. Activation of microglia was measured by flow cytometry. Pro-inflammatory M1 type (MHC-II, CD40, CD54, CD80, CD86, CCR7), anti-inflammatory M2 type (CD206, CD200R), and maturation markers (CD11c, CCR7) were tested, as well as the chemokine receptor CCR2. IFN-α led to a significant increase in depressive-like behavior and expression of the pro-inflammatory surface markers MHC-II, CD86, and CD54, indicating M1 polarization. Because IFN-α-treated mice showed great individual variance in the behavioral response to IFN-α, they were further divided into vulnerable and non-vulnerable subgroups. Only IFN-α vulnerable mice (characterized by their development of depressive-like behavior in response to IFN-α) showed an increased expression of MHC-II and CD86, while CD54 was similarly enhanced in both subgroups. Thus, IFN-α-induced activation of microglia was specifically associated with depressive-like behavior. PMID:26408795

  13. Abrogation of IFN-γ mediated epithelial barrier disruption by serine protease inhibition

    PubMed Central

    Willemsen, LEM; Hoetjes, JP; Van Deventer, SJH; Van Tol, EAF

    2005-01-01

    The intestinal barrier function is often impaired in a variety of diseases including chronic inflammatory bowel disease. Increased intestinal permeability during episodes of active disease correlates with destruction or rearrangement of the tight junction protein complex. IFN-γ has been widely studied for its effect on barrier function and tight junction structures but its mode of action remains unclear. Since the claudin family of tight junction proteins is proposed to be involved in barrier maintenance we studied the effect of IFN-γ on claudin expression in relation to epithelial barrier function. Cycloheximide and protease inhibitors were used to study mechanisms of IFN-γ mediated barrier disruption. Intestinal epithelial cells were exposed to IFN-γ and permeability was evaluated by horse radish peroxidase (HRP) and 4 kD FITC-dextran fluxes. Occludin and claudin-1, -2, -3, and -4 tight junction protein expression was determined by Western blotting. Occludin and claudin-2 protein expression was dramatically reduced after IFN-γ exposure, which correlated with increased permeability for HRP and FITC-dextran. Interestingly, cleavage of claudin-2 was observed after incubation with IFN-γ. Serine protease inhibitor AEBSF completely abrogated IFN-γ mediated barrier disruption which was associated with preservation of claudin-2 expression. Moreover, IFN-γ induced loss of barrier integrity was found to affect claudin-2 and occludin expression through different mechanisms. Since inhibition of serine protease activity abrogates IFN-γ mediated barrier disruption this may be an important target for therapeutic intervention. PMID:16232214

  14. Type I IFN signaling triggers immunopathology in tuberculosis-susceptible mice by modulating lung phagocyte dynamics

    PubMed Central

    Dorhoi, Anca; Yeremeev, Vladimir; Nouailles, Geraldine; Weiner, January; Jörg, Sabine; Heinemann, Ellen; Oberbeck-Müller, Dagmar; Knaul, Julia K; Vogelzang, Alexis; Reece, Stephen T; Hahnke, Karin; Mollenkopf, Hans-Joachim; Brinkmann, Volker; Kaufmann, Stefan H E

    2014-01-01

    General interest in the biological functions of IFN type I in Mycobacterium tuberculosis (Mtb) infection increased after the recent identification of a distinct IFN gene expression signature in tuberculosis (TB) patients. Here, we demonstrate that TB-susceptible mice lacking the receptor for IFN I (IFNAR1) were protected from death upon aerogenic infection with Mtb. Using this experimental model to mimic primary progressive pulmonary TB, we dissected the immune processes affected by IFN I. IFNAR1 signaling did not affect T-cell responses, but markedly altered migration of inflammatory monocytes and neutrophils to the lung. This process was orchestrated by IFNAR1 expressed on both immune and tissue-resident radioresistant cells. IFNAR1-driven TB susceptibility was initiated by augmented Mtb replication and in situ death events, along with CXCL5/CXCL1-driven accumulation of neutrophils in alveoli, followed by the discrete compartmentalization of Mtb in lung phagocytes. Early depletion of neutrophils rescued TB-susceptible mice to levels observed in mice lacking IFNAR1. We conclude that IFN I alters early innate events at the site of Mtb invasion leading to fatal immunopathology. These data furnish a mechanistic explanation for the detrimental role of IFN I in pulmonary TB and form a basis for understanding the complex roles of IFN I in chronic inflammation. PMID:24782112

  15. IFN-beta-induced reduction of superoxide anion generation by macrophages.

    PubMed Central

    Boraschi, D; Ghezzi, P; Salmona, M; Tagliabue, A

    1982-01-01

    Resident mouse peritoneal macrophages (M phi) produced significant amounts of superoxide anion (O2-) in response to phagocytic stimuli. When M phi were exposed in vitro for 20 hr to fibroblast interferon (IFN-beta), their capacity to release O2- was significantly reduced, such reduction being more evident with increasing IFN-beta concentrations. In contrast, O2- production by M phi exposed for 20 hr to the lymphokine macrophage activating factor (MAF) or treated with either MAF or IFN-beta for 4 hr was not significantly different from that of control cells. This pattern of activity closely followed that of M phi-mediated suppression of lymphocyte proliferation, which was dramatically reduced by 20 hr exposure of M phi to IFN-beta, but unchanged by treatment with MAF. No correlation was however found between superoxide anion generation and enhancement of tumoricidal capacity in IFN-beta-treated M phi. We thus concluded that O2- does not play a relevant role in IFN-beta-induced M phi cytolysis, whereas the reduction of O2- production could be of major importance in the decrease of M phi suppression induced by IFN-beta. PMID:6175565

  16. Elevated Levels of IFN-γ in CSF and Serum of Patients with Amyotrophic Lateral Sclerosis

    PubMed Central

    Liu, Juan; Gao, Lina; Zang, Dawei

    2015-01-01

    Objectives To explore whether the levels of IFN-γ in cerebral spinal fluid (CSF) and serum are elevated in ALS patients and to analyze the correlations between the IFN-γ levels and disease progression. Methods CSF and serum samples were obtained from 52 ALS patients and 31 non-ALS patients. The levels of IFN-γ in CSF and serum were assessed, and disease progression parameters, including the disease interval (months from onset, MFO), the revised ALS Functional Rating Scale (ALSFRS-r) score and the disease progression rate (DPR) were analyzed by registered neurologists. All samples were measured using a commercial enzyme-linked immunosorbent assay. Statistical analyses were performed using Prism software. Results Compared to the non-ALS patients, the ALS patients displayed significantly increased levels of IFN-γ in both CSF and serum, and these values consistently correlated with disease progression. Conclusions These results demonstrated that IFN-γ in CSF may serve as a biomarker of ALS differentiation and progression. CSF IFN-γ was a more reliable biomarker of disease diagnosis and progression than serum IFN-γ. PMID:26332465

  17. Screening and characterization of molecules that modulate the biological activity of IFNs-I.

    PubMed

    Bürgi, Milagros; Zapol'skii, Viktor A; Hinkelmann, Bettina; Köster, Mario; Kaufmann, Dieter E; Sasse, Florenz; Hauser, Hansjörg; Etcheverrigaray, Marina; Kratje, Ricardo; Bollati-Fogolín, Mariela; Oggero, Marcos

    2016-09-10

    Type I Interferons (IFNs-I) are species-specific glycoproteins which play an important role as primary defence against viral infections and that can also modulate the adaptive immune system. In some autoimmune diseases, interferons (IFNs) are over-produced. IFNs are widely used as biopharmaceuticals for a variety of cancer indications, chronic viral diseases, and for their immuno-modulatory action in patients with multiple sclerosis; therefore, increasing their therapeutic efficiency and decreasing their side effects is of high clinical value. In this sense, it is interesting to find molecules that can modulate the activity of IFNs. In order to achieve that, it was necessary to establish a simple, fast and robust assay to analyze numerous compounds simultaneously. We developed four reporter gene assays (RGAs) to identify IFN activity modulator compounds by using WISH-Mx2/EGFP, HeLa-Mx2/EGFP, A549-Mx2/EGFP, and HEp2-Mx2/EGFP reporter cell lines (RCLs). All of them present a Z' factor higher than 0.7. By using these RGAs, natural and synthetic compounds were analyzed simultaneously. A total of 442 compounds were studied by the Low Throughput Screening (LTS) assay using the four RCLs to discriminate between their inhibitory or enhancing effects on IFN activity. Some of them were characterized and 15 leads were identified. Finally, one promising candidate with enhancing effect on IFN-α/-β activity and five compounds with inhibitory effect were described. PMID:27346232

  18. Induction of embryonic major histocompatibility complex antigen expression by gamma-IFN.

    PubMed

    Warner, C M; Almquist, C D; Toulimat, M H; Xu, Y

    1993-07-01

    Preimplantation mouse embryos were incubated in vitro with mouse recombinant gamma-interferon (IFN). The effect of the gamma-IFN on major histocompatibility complex (MHC) class I antigen expression was tested using an ELISA procedure. It was found that there is a doubling of Db antigens and a tripling of Qa-2 antigens on C57BL/6 mouse embryos cultured from the 8-cell stage for 24 h in the presence of 10(5) units/ml gamma-IFN. The effect of gamma-IFN on the rate of preimplantation embryonic development was tested by culturing 2-cell embryos for 48 h and 8-cell embryos for 24 h in the presence of varying concentrations of gamma-IFN up to 10(6) units/ml. Two methods were used to assess the cell number per embryo after the culture period: incorporation of [3H]thymidine into DNA, and direct counting of nuclei in fixed and stained embryos. Both methods showed that treatment with gamma-IFN increases the rate of development of preimplantation mouse embryos. Since rate of preimplantation embryonic development is genetically controlled by the Ped gene, it is suggested that gamma-IFN has a direct effect on the Ped gene phenotype of preimplantation mouse embryos. PMID:8229991

  19. Virus-induced type I IFN stimulates generation of immunoproteasomes at the site of infection

    PubMed Central

    Shin, Eui-Cheol; Seifert, Ulrike; Kato, Takanobu; Rice, Charles M.; Feinstone, Stephen M.; Kloetzel, Peter-M.; Rehermann, Barbara

    2006-01-01

    IFN-γ is known as the initial and primary inducer of immunoproteasomes during viral infections. We now report that type I IFN induced the transcription and translation of immunoproteasome subunits, their incorporation into the proteasome complex, and the generation of an immunoproteasome-dependent CD8 T cell epitope in vitro and provide in vivo evidence that this mechanism occurs prior to IFN-γ responses at the site of viral infection. Type I IFN–mediated generation of immunoproteasomes was initiated by either poly(I:C) or HCV RNA in human hepatoma cells and was inhibited by neutralization of type I IFN. In serial liver biopsies of chimpanzees with acute HCV infection, increases in immunoproteasome subunit mRNA preceded intrahepatic IFN-γ responses by several weeks, instead coinciding with intrahepatic type I IFN responses. Thus, viral RNA–induced innate immune responses regulate the antigen-processing machinery, which occurs prior to the detection of IFN-γ at the site of infection. This mechanism may contribute to the high effectiveness (95%) of type I IFN–based therapies if administered early during HCV infection. PMID:17039255

  20. Follistatin-like protein 1 promotes arthritis by up-regulating IFN-gamma.

    PubMed

    Clutter, Suzanne D; Wilson, David C; Marinov, Anthony D; Hirsch, Raphael

    2009-01-01

    Follistatin-like protein-1 (FSTL-1) is a poorly characterized protein that is up-regulated in the early stage of collagen-induced arthritis and that exacerbates arthritis when delivered by gene transfer. The current study was designed to determine the mechanism by which FSTL-1 promotes arthritis. FSTL-1 was injected into mouse paws, resulting in severe paw swelling associated with up-regulation of IFN-gamma transcript and the IFN-gamma-induced chemokine, CXCL10. Mice depleted of T cells were protected. A central role for IFN-gamma was confirmed by the finding that mice deficient in IFN-gamma failed to exhibit paw swelling in response to injection of FSTL-1. Furthermore, IFN-gamma secretion from mouse spleen cells exposed to a weak TCR signal was increased 5-fold in the presence of FSTL-1. FSTL-1 could be induced by innate immune signals, including TLR4 agonists and the arthritogenic cytokine, IL-1beta, via an NFkappaB pathway. Finally, FSTL-1 was found to be overexpressed in human arthritis and its neutralization inhibited murine collagen-induced arthritis and suppressed IFN-gamma and CXCL10 production in arthritic joints. These findings demonstrate that FSTL-1 plays a critical role in arthritis by enhancing IFN-gamma signaling pathways and suggest a mechanism by which FSTL-1 bridges innate and adaptive immune responses. PMID:19109154

  1. Hexabromocyclododecane and tetrabromobisphenol A alter secretion of interferon gamma (IFN-γ) from human immune cells.

    PubMed

    Almughamsi, Haifa; Whalen, Margaret M

    2016-07-01

    Hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA) are brominated flame-retardant compounds used in a variety of applications including insulation, upholstery, and epoxy resin circuit boards. Interferon gamma (IFN-γ) is an inflammatory cytokine produced by activated T and NK cells that regulates immune responsiveness. HBCD and TBBPA are found in human blood, and previous studies have shown that they alter the ability of human natural killer (NK) lymphocytes to destroy tumor cells. This study examines whether HBCD and TBBPA affect the secretion of IFN-γ from increasingly complex preparations of human immune cells-purified NK cells, monocyte-depleted (MD) peripheral blood mononuclear cells (PBMCs), and PBMCs. Both HBCD and TBBPA were tested at concentrations ranging from 0.05 to 5 µM. HBCD generally caused increases in IFN-γ secretion after 24-h, 48-h, and 6-day exposures in each of the different cell preparations. The specific concentration of HBCD that caused increases as well as the magnitude of the increase varied from donor to donor. In contrast, TBBPA tended to decrease secretion of IFN-γ from NK cells, MD-PBMCs, and PBMCs. Thus, exposure to these compounds may potentially disrupt the immune regulation mediated by IFN-γ. Signaling pathways that have the capacity to regulate IFN-γ production (nuclear factor kappa B (NF-κB), p44/42, p38, JNK) were examined for their role in the HBCD-induced increases in IFN-γ. Results showed that the p44/42 (ERK1/2) MAPK pathway appears to be important in HBCD-induced increases in IFN-γ secretion from human immune cells. PMID:26302867

  2. IL-15 complexes induce NK- and T-cell responses independent of type I IFN signaling during rhinovirus infection.

    PubMed

    Jayaraman, A; Jackson, D J; Message, S D; Pearson, R M; Aniscenko, J; Caramori, G; Mallia, P; Papi, A; Shamji, B; Edwards, M; Westwick, J; Hansel, T; Stanciu, L A; Johnston, S L; Bartlett, N W

    2014-09-01

    Rhinoviruses are among the most common viruses to infect man, causing a range of serious respiratory diseases including exacerbations of asthma and COPD. Type I IFN and IL-15 are thought to be required for antiviral immunity; however, their function during rhinovirus infection in vivo is undefined. In RV-infected human volunteers, IL-15 protein expression in fluid from the nasal mucosa and in bronchial biopsies was increased. In mice, RV induced type I IFN-dependent expressions of IL-15 and IL-15Rα, which in turn were required for NK- and CD8(+) T-cell responses. Treatment with IL-15-IL-15Rα complexes (IL-15c) boosted RV-induced expression of IL-15, IL-15Rα, IFN-γ, CXCL9, and CXCL10 followed by recruitment of activated, IFN-γ-expressing NK, CD8(+), and CD4(+) T cells. Treating infected IFNAR1(-/-) mice with IL-15c similarly increased IL-15, IL-15Rα, IFN-γ, and CXCL9 (but not CXCL10) expression also followed by NK-, CD8(+)-, and CD4(+)-T-cell recruitment and activation. We have demonstrated that type I IFN-induced IFN-γ and cellular immunity to RV was mediated by IL-15 and IL-15Rα. Importantly, we also show that IL-15 could be induced via a type I IFN-independent mechanism by IL-15 complex treatment, which in turn was sufficient to drive IFN-γ expression and lymphocyte responses. PMID:24472849

  3. Recombinant interferon-gamma (rIFN-gamma) in dermatology.

    PubMed

    Mahrle, G; Schulze, H J

    1990-12-01

    This paper gives a short review on the function, pharmacokinetics, and therapeutic application of recombinant interferon-gamma (rIFN-gamma) in dermatology. Simultaneously, our own experiences are presented for 57 patients (phase II study) suffering from genital warts (21 patients), psoriatic arthritis (10 patients), psoriasis vulgaris (three patients), malignant melanoma (six patients), bowenoid papulosis (four patients), Behcet's disease (four patients), basal cell carcinoma (six patients), as well as herpes simplex recidivans, epidermodysplasia verruciformis, and mycosis fungoides (one patient each). We conclude that there might be an indication for treatment with rIFN-gamma in genital warts, bowenoid papulosis, Behcet's disease, and microbial infections, such as leprosy and cutaneous leishmaniasis. Even though there are reports of a limited beneficial effect of rIFN-gamma on arthritis and skin lesions in psoriasis, we failed to observe any in 10 patients. The main side effects in our low-dose study (50-100 micrograms/d) were mild fever (78%), fatigue (78%), and myalgia (65%). Laboratory tests revealed an increase in the serum triglyceride level, in particular, in psoriatic patients. PMID:2124242

  4. Autoimmunity-associated protein tyrosine phosphatase PEP negatively regulates IFN-α receptor signaling

    PubMed Central

    Holmes, Derek A.; Suto, Eric; Lee, Wyne P.; Ou, Qinglin; Gong, Qian; Smith, Hamish R.C.; Caplazi, Patrick

    2015-01-01

    The protein tyrosine phosphatase PTPN22(C1858T) allelic polymorphism is associated with increased susceptibility for development of systemic lupus erythematosus (SLE) and other autoimmune diseases. PTPN22 (also known as LYP) and its mouse orthologue PEP play important roles in antigen and Toll-like receptor signaling in immune cell functions. We demonstrate here that PEP also plays an important inhibitory role in interferon-α receptor (IFNAR) signaling in mice. PEP co-immunoprecipitates with components of the IFNAR signaling complex. Pep−/− hematopoietic progenitors demonstrate increased IFNAR signaling, increased IFN-inducible gene expression, and enhanced proliferation and activation compared to Pep+/+ progenitors in response to IFN-α. In addition, Pep−/− mice treated with IFN-α display a profound defect in hematopoiesis, resulting in anemia, thrombocytopenia, and neutropenia when compared to IFN-α–treated Pep+/+ mice. As SLE patients carrying the PTPN22(C1858T) risk variant have higher serum IFN-α activity, these data provide a molecular basis for how type I IFNs and PTPN22 may cooperate to contribute to lupus-associated cytopenias. PMID:26077719

  5. IFN-gamma reduces specific binding of tumor necrosis factor on murine macrophages

    SciTech Connect

    Drapier, J.C.; Wietzerbin, J. )

    1991-02-15

    Because IFN-gamma is the main cytokine activating macrophages and TNF cooperates in this activation, we assessed TNF binding capacity during the course of murine macrophage activation by IFN-gamma. TNF binding to elicited macrophages increased with time, was maximal by 8 h of culture, and required de novo protein synthesis. {sup 125}I-TNF bound to about 40,000 sites/cell with a Kd of 1 x 10(-9) M. Cross-linking experiments performed with a bifunctional cross-linking agent revealed a specific band with a m.w. of 94,000. Preincubation of macrophages with IFN-gamma prevented the binding of TNF to receptors. This effect was dose-dependent and maximal at 100 U/ml. IFN-gamma also reduced specific TNF binding to preexisting receptors (50% inhibition in 3 h), but IFN-gamma did not change the internalization rate of TNF. These studies showed that the number of TNF receptors increased on macrophages vs maturation in culture and was negatively controlled by IFN-gamma.

  6. Induction of ceruloplasmin synthesis by IFN-gamma in human monocytic cells

    NASA Technical Reports Server (NTRS)

    Mazumder, B.; Mukhopadhyay, C. K.; Prok, A.; Cathcart, M. K.; Fox, P. L.

    1997-01-01

    Ceruloplasmin is a 132-kDa glycoprotein abundant in human plasma. It has multiple in vitro activities, including copper transport, lipid pro- and antioxidant activity, and oxidation of ferrous ion and aromatic amines; however, its physiologic role is uncertain. Although ceruloplasmin is synthesized primarily by the liver in adult humans, production by cells of monocytic origin has been reported. We here show that IFN-gamma is a potent inducer of ceruloplasmin synthesis by monocytic cells. Activation of human monoblastic leukemia U937 cells with IFN-gamma increased the production of ceruloplasmin by at least 20-fold. The identity of the protein was confirmed by plasmin fingerprinting. IFN-gamma also increased ceruloplasmin mRNA. Induction followed a 2- to 4-h lag and was partially blocked by cycloheximide, indicating a requirement for newly synthesized factors. Ceruloplasmin induction in monocytic cells was agonist specific, as IL-1, IL-4, IL-6, IFN-alpha, IFN-beta, TNF-alpha, and LPS were completely ineffective. The induction was also cell type specific, as IFN-gamma did not induce ceruloplasmin synthesis in endothelial or smooth muscle cells. In contrast, IFN-gamma was stimulatory in other monocytic cells, including THP-1 cells and human peripheral blood monocytes, and also in HepG2 cells. Ceruloplasmin secreted by IFN-gamma-stimulated U937 cells had ferroxidase activity and was, in fact, the only secreted protein with this activity. Monocytic cell-derived ceruloplasmin may contribute to defense responses via its ferroxidase activity, which may drive iron homeostasis in a direction unfavorable to invasive organisms.

  7. IFN-γ induces lipogenesis in mouse mesangial cells via the JAK2/STAT1 pathway.

    PubMed

    Hao, Jun; Zhang, Yu-jun; Lv, Xin; Xu, Ning; Liu, Qin-juan; Zhao, Song; Feng, Xiao-juan; Xing, Ling-ling; Kang, Peng-peng; Li, Gui-ying; Liu, Shu-xia

    2013-04-15

    The objective is to investigate the effect of high mobility group box-1 (HMGB1) on lipid deposition in γ-interferon (IFN-γ)-stimulated mouse mesangial cell line (MMC) and to determine whether the Janus kinase 2 and signal transducer and activator of transcription 1 (JAK2/STAT1) signaling pathway plays an important role in this process. We employed a control group, an IFN-γ stimulation group, and an IFN-γ + AG490 (JAK2 inhibitor) group. RNA interference aimed at sterol regulatory element-binding protein-1 (SREBP-1) or HMGB1 was used to investigate the effect of these proteins on IFN-γ-induced lipid deposition. Western blotting was used to detect phospho (p)-JAK2, JAK2, p-STAT1, STAT1, SREBP-1, fatty acid synthase (FAS), and HMGB1 protein expression. RT-PCR was used to detect SREBP-1, FAS, and HMGB1 mRNA. Oil Red O staining and the triglyceride assay were used to detect lipid deposition and triglyceride content. Results were as follows: 1) IFNincreased MMC cell lipid deposition, triglyceride content, and p-JAK2, p-STAT1, SREBP-1, and FAS expression; 2) SREBP-1 inhibition prevented FAS upregulation and attenuated IFN-γ-induced MMC cell lipid deposition and triglyceride content; 3) HMGB1 upregulated SREBP-1 and FAS mRNA and protein levels, which increased lipid deposition in MMC cells. Small interfering RNA-mediated inhibition of HMGB1 decreased SREBP-1 and FAS expression and lipid accumulation; 4) AG490 decreased upregulation of HMGB1 and p-JAK2/p-STAT1, as well as IFN-γ-induced lipogenesis. In conclusion, the JAK2/STAT1 pathway mediates IFN-γ-induced lipogenesis in MMC cells through regulation of HMGB1/SREBP-1/FAS. PMID:23407880

  8. Enhanced protection from fibrosis and inflammation in the combined absence of IL-13 and IFN-γ.

    PubMed

    Ramalingam, Thirumalai R; Gieseck, Richard L; Acciani, Thomas H; M Hart, Kevin; Cheever, Allen W; Mentink-Kane, Margaret M; Vannella, Kevin M; Wynn, Thomas A

    2016-07-01

    Persistent or dysregulated IL-13 responses are key drivers of fibrosis in multiple organ systems, and this identifies this cytokine as an important therapeutic target. Nevertheless, the mechanisms by which IL-13 blockade leads to the amelioration of fibrosis remain unclear. Because IFN-γ exhibits potent anti-fibrotic activity, and IL-4Rα signalling antagonizes IFN-γ effector function, compensatory increases in IFN-γ activity following IL-13/IL-4Rα blockade might contribute to the reduction in fibrosis. To investigate the role of IFN-γ, we developed novel IL-13(-/-) /IFN-γ(-/-) double cytokine-deficient mice and examined disease progression in models of type 2-driven fibrosis. As predicted, we showed that fibrosis in the lung and liver are both highly dependent on IL-13. We also observed increased IFN-γ production and inflammatory activity in the tissues of IL-13-deficient mice. Surprisingly, however, an even greater reduction in fibrosis was observed in IL-13/IFN-γ double deficient mice, most notably in the livers of mice chronically infected with Schistosoma mansoni. The increased protection was associated with marked decreases in Tgfb1, Mmp12, and Timp1 mRNA expression in the tissues; reduced inflammation; and decreased expression of important pro-inflammatory mediators such as TNF-α. Experiments conducted with neutralizing monoclonal antibodies to IL-13 and IFN-γ validated the findings with the genetically deficient mice. Together, these studies demonstrate that the reduction in fibrosis observed when IL-13 signalling is suppressed is not dependent on increased IFN-γ activity. Instead, by reducing compensatory increases in type 1-associated inflammation, therapeutic strategies that block IFN-γ and IL-13 activity simultaneously can confer greater protection from progressive fibrosis than IL-13 blockade alone. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. PMID:27125685

  9. Regression of infancy hemangiomas with recombinant IFN-alpha 2b.

    PubMed

    Garmendía, G; Miranda, N; Borroso, S; Longchong, M; Martínez, E; Ferrero, J; Porrero, P; López-Saura, P

    2001-01-01

    Interferon-alpha (IFN-alpha) has antitumor and antiangiogenic effects. The purpose of this work was to evaluate its efficacy and safety in the treatment of infancy hemangioma and to monitor the appearance of anti-IFN antibodies in these patients. Thirty-nine children (29 girls) aged 1.5-158 months, with 19 younger than 1 year and 9 older than 5, were treated with 3 x 10(6) IU/m(2) IFN-alpha 2b, subcutaneously (s.c.) daily. Inclusion criteria were life-threatening or life-limiting hemangioma and parents' informed consent. Regression was considered if tumor size diminished by 50% or more. Of the 38 patients who completed 6 months of treatment, 27 (71.1%) had regression and 11 (28.9%) had stable disease. No patient experienced progression. Regression was more frequent (100%) among patients between 1 and 5 years old, but it was particularly important (68%) among those under 1 year old, when spontaneous regression is rare. The main side effects were the IFN-related flulike syndrome (79%), increase in serum alanine aminotransferase (ALT) (28%), anorexia (19%), and mild inflammation at the injection site (19%). There was no effect on psychomotor or physical development. On the contrary, 1 patient with neurologic symptoms improved remarkably, including seizure disappearance. Eight patients developed anti-IFN-alpha 2 neutralizing antibodies, and 7 of them responded to IFN treatment. IFN-alpha 2b is a safe and efficacious treatment of infancy hemangioma. Further work should look for other treatment schedules and ways of administration and carefully monitor anti-IFN neutralizing antibodies, which does not seem to interfere with response. PMID:11177578

  10. Genkwadaphnin Induces IFN-γ via PKD1/NF-κB/STAT1 Dependent Pathway in NK-92 Cells

    PubMed Central

    Kang, Ho-Bum; Ahn, Kyung-Seop; Oh, Sei-Ryang; Kim, Jae Wha

    2014-01-01

    The flower buds of Daphne genkwa Sieb. et Zucc. have been used as a traditional Chinese medicine although their functional mechanisms have not been discovered yet. We have studied the potential effects of the plant extracts on natural killer (NK) cell activation, and isolated an active fraction. Genkwadaphnin (GD-1) displayed a potent efficacy to induce IFN-γ transcription in NK cells with concentration- and time-dependent manners. GD-1 treatment triggered the phosphorylation of PKD1, a member of PKC family, MEK and ERK, resulting in IKK activation to induce IκB degradation, and the nuclear localization of p65, an NF-κB subunit, which regulates IFN-γ transcription. GD-1 effect on IFN-γ production was blocked by the addition of Rottlerin, a PKC inhibitor, CID 755673, a PKD inhibitor, or Bay11-7082, an IKKα inhibitor. The nuclear localization of p65 was also inhibited by the kinase inhibitors. Secreted IFN-γ activates STAT1 phosphorylation as autocrine-loops to sustain its secretion. GD-1 induced the phosphorylation of STAT1 probably through the increase of IFN-γ. STAT1 inhibitor also abrogated the sustained IFN-γ secretion. These results suggest that GD-1 is involved in the activation of PKD1 and/or ERK pathway, which activate NK-κB triggering IFN-γ production. As positive feedback loops, secreted IFN-γ activates STAT1 and elongates its production in NK-92 cells. PMID:25517939

  11. Cloning and characterization of a novel feline IFN-omega.

    PubMed

    Yang, Li-Min; Xue, Qing-Hua; Sun, Lei; Zhu, Yi-Ping; Liu, Wen-Jun

    2007-02-01

    The interferons (IFNs) are a large family of multifunctional secreted protein involved in antiviral defense, cell growth regulation, and immune activation. The human IFNs are used worldwide as antiviral drugs. Here, we present cDNAs encoding 13 novel feline IFN-omega (FeIFN-omega) subtypes that share 95%-99% amino acid sequence identity. FeIFN-omega2 and FeIFN-omega4 have seven additional amino acids at position 109 that are not present in other subtypes. Sequence identity of the present FeIFN proteins encoded by the 13 subtypes is approximately 57% compared with human IFN-omega (HuIFN-omega). All 13 FeIFN-omega subtypes were expressed in Escherichia coli using a periplasmic expression system. The antiviral activity of each product was evaluated in vitro. In addition, subtype FeIFN-omega2 was cytoplasm expressed in E. coli and secretion expressed in Pichia pastoris. The purified mature recombinant protein demonstrated significant antiviral activity on both homologous and heterologous animal cells in vitro. PMID:17316139

  12. Surfactant Protein A Prevents IFN-γ/IFN-γ Receptor Interaction and Attenuates Classical Activation of Human Alveolar Macrophages.

    PubMed

    Minutti, Carlos M; García-Fojeda, Belén; Sáenz, Alejandra; de Las Casas-Engel, Mateo; Guillamat-Prats, Raquel; de Lorenzo, Alba; Serrano-Mollar, Anna; Corbí, Ángel L; Casals, Cristina

    2016-07-15

    Lung surfactant protein A (SP-A) plays an important function in modulating inflammation in the lung. However, the exact role of SP-A and the mechanism by which SP-A affects IFN-γ-induced activation of alveolar macrophages (aMϕs) remains unknown. To address these questions, we studied the effect of human SP-A on rat and human aMϕs stimulated with IFN-γ, LPS, and combinations thereof and measured the induction of proinflammatory mediators as well as SP-A's ability to bind to IFN-γ or IFN-γR1. We found that SP-A inhibited (IFN-γ + LPS)-induced TNF-α, iNOS, and CXCL10 production by rat aMϕs. When rat macrophages were stimulated with LPS and IFN-γ separately, SP-A inhibited both LPS-induced signaling and IFN-γ-elicited STAT1 phosphorylation. SP-A also decreased TNF-α and CXCL10 secretion by ex vivo-cultured human aMϕs and M-CSF-derived macrophages stimulated by either LPS or IFN-γ or both. Hence, SP-A inhibited upregulation of IFN-γ-inducible genes (CXCL10, RARRES3, and ETV7) as well as STAT1 phosphorylation in human M-CSF-derived macrophages. In addition, we found that SP-A bound to human IFN-γ (KD = 11 ± 0.5 nM) in a Ca(2+)-dependent manner and prevented IFN-γ interaction with IFN-γR1 on human aMϕs. We conclude that SP-A inhibition of (IFN-γ + LPS) stimulation is due to SP-A attenuation of both inflammatory agents and that the binding of SP-A to IFN-γ abrogates IFN-γ effects on human macrophages, suppressing their classical activation and subsequent inflammatory response. PMID:27271568

  13. The anti-proliferative effects of type I IFN involve STAT6-mediated regulation of SP1 and BCL6.

    PubMed

    Hsu, Yu-An; Huang, Chi-Chun; Kung, Yung-Jen; Lin, Hui-Ju; Chang, Ching-Yao; Lee, Kuan-Rong; Wan, Lei

    2016-06-01

    Type I IFN-induced STAT6 has been shown to have anti-proliferative effects in Daudi and B cells. IFN-sensitive (DS) and IFN-resistant (DR) subclones of Daudi cells were used to study the role of STAT6 in the anti-proliferative activities. Type I IFN significantly increased STAT6 mRNA and protein expression in DS but not DR cells. STAT6 knockdown significantly reduced the sensitivity to IFN in both cell lines. The molecular targets and functional importance of IFN-activated STAT6 were performed by chromatin immunoprecipitation-on-chip (ChIP-on-chip) experiments in type I IFN-treated Daudi cells. Two target genes (Sp1 and BCL6) were selected from the ChIP-on-chip data. IFN-induced STAT6 activation led to Sp1 upregulation and BCL6 downregulation in DS cells, with only minimal effects in DR cells. siRNA inhibition of STAT6 expression resulted in decreased Sp1 and BCL6 mRNA and protein levels in both DS and DR cells. IFN treatment did not increase Sp1 and BCL6 expression in a STAT2-deficient RST2 cell line, and this effect was mitigated by plasmid overexpression of STAT2, indicating that STAT2 is important for STAT6 activation. These results suggest that STAT6 plays an important role in regulating Sp1 and BCL6 through STAT2 to exert the anti-proliferative effects of type I IFN. PMID:26945968

  14. Prevention of SHIV transmission by topical IFN-β treatment

    PubMed Central

    Veazey, Ronald S.; Pilch Cooper, Heather A.; Hope, Thomas J.; Alter, Galit; Carias, Ann M.; Sips, Magdalena; Wang, Xiaolei; Rodriguez, Benigno; Sieg, Scott F.; Reich, Adrian; Wilkinson, Peter; Cameron, Mark J.; Lederman, Michael M.

    2015-01-01

    Understanding vaginal and rectal HIV transmission and protective cellular and molecular mechanisms is critical for designing new prevention strategies, including those required for an effective vaccine. The determinants of protection against HIV infection are, however, poorly understood. Increasing evidence suggest that innate immune defenses may help protect mucosal surfaces from HIV transmission in highly exposed, uninfected subjects 1. More recent studies suggest that systemically administered type 1 interferon protects against simian immunodeficiency virus infection of macaques 2. Here we hypothesized that topically applied type 1 interferons might stimulate vaginal innate responses that could protect against HIV transmission. We therefore applied a recombinant human type 1 interferon (IFN-β) to the vagina of rhesus macaques and vaginally challenged them with pathogenic simian/human immunodeficiency virus (SHIV). Vaginal administration of IFN-β resulted in marked local changes in immune cell phenotype, increasing immune activation and HIV coreceptor expression, yet provided significant protection from SHIV acquisition as interferon response genes (IRGs) were also upregulated. These data suggest that protection from vaginal HIV acquisition may be achieved by activating innate mucosal defenses. PMID:26838048

  15. Comparative transcriptome analyses indicate enhanced cellular protection against FMDV in PK15 cells pretreated with IFN-γ.

    PubMed

    Fu, Yin; Zhu, Zesen; Chang, Huiyun; Liu, Zaixin; Liu, Jing; Chen, Huiyong

    2016-07-25

    Interferon gamma (IFN-γ) can induce a host antiviral response to foot and mouth disease virus (FMDV) in vivo and in vitro. To elucidate the mechanism of IFN-γ anti FMDV infection in host cells, high-throughput RNA sequencing was analyzed for systemic changes in gene expression profiles in PK15 cells infected by FMDV with or without IFN-γ pretreatment. More than 25 million reads, covering 1.2-1.5 Gb, were analyzed from each experiment panel. FMDV challenge altered the transcription of genes involved in positively and negatively regulating cell death or apoptosis; however, the expected immune suppression response was not obvious. IFN-γ pretreatment combined with FMDV infection normalized the increase in apoptosis. Furthermore, the transcription factors required for IFN-γ functioning, STAT1 and IRF1 were up-regulated by IFN-γ pretreatment and stimulated downstream IFN-stimulated genes (ISGs). These induced ISGs are mainly responsible for antigen processing, antigen presentation or antiviral defense. Interestingly, a synergistic effect on some ISGs, including OAS1, OAS2, MX1, MX2, RIG-I and IFIT1, was observed in the combined treatment compared to the IFN-γ treatment alone. The suggested effects identified by RNA sequencing were consistent with cellular morphology changes and confirmed by related protein markers. This is the first report exploring transcriptome alterations introduced by FMDV infection with or without IFN-γ pretreatment. The identified key host genes that control cell survival in vitro broaden our comprehensive understanding of how IFN-γ inhibits FMDV infection and may shed light on developing improved FMD control approaches. PMID:27018244

  16. New perspectives on type I IFNs in cancer.

    PubMed

    Gajewski, Thomas F; Corrales, Leticia

    2015-04-01

    Although type I IFNs were initially described based on their anti-viral properties, it was quickly realized that these cytokines had anti-proliferative and anti-cancer activities. These observations ultimately led to the clinical development and utility of IFN-α2b for the treatment of patients with melanoma, renal cell carcinoma, and chronic myelogenous leukemia, among others. However, the mechanism of action of type I IFNs in vivo was never fully elucidated, and the pleiotropic effects of IFNs on multiple cell types had made it challenging to decipher. Advancement of genetically engineered mouse models has provided new tools for interrogating these mechanisms. Recent evidence has indicated that spontaneous innate immune sensing of cancers that leads to adaptive immune responses is dependent on host type I IFN production and signaling. The major innate immune receptor pathway that leads to type I IFN production in response to a growing tumor appears to be the STING pathway of cytosolic DNA sensing. STING agonists drive type I IFN production and are impressively therapeutic in mouse tumor models. Targeting low doses of type I IFNs to the tumor microenvironment also promotes anti-tumor activity via host adaptive immunity that is T cell-dependent. However, high doses of intratumoral type I IFNs largely function via an anti-angiogenic effect. Understanding these mechanistic details should enable improved clinical manipulation of the type I IFN system in cancer. PMID:25630967

  17. IFN-Alpha-Induced Cortical and Subcortical Glutamate Changes Assessed by Magnetic Resonance Spectroscopy

    PubMed Central

    Haroon, Ebrahim; Woolwine, Bobbi J; Chen, Xiangchuan; Pace, Thaddeus W; Parekh, Samir; Spivey, James R; Hu, Xiaoping P; Miller, Andrew H

    2014-01-01

    Cytokine effects on behavior may be related to alterations in glutamate metabolism. We therefore measured glutamate concentrations in brain regions shown to be affected by inflammatory stimuli including the cytokine interferon (IFN)-alpha. IFN-alpha is known to alter neural activity in the dorsal anterior cingulate cortex (dACC) and basal ganglia in association with symptoms of depression and increases in peripheral cytokines including the tumor necrosis factor (TNF) and its soluble receptor. Single-voxel magnetic resonance spectroscopy (MRS) was employed to measure glutamate concentrations normalized to creatine (Glu/Cr) in dACC and basal ganglia of 31 patients with hepatitis C before and after ∼1 month of either no treatment (n=14) or treatment with IFN-alpha (n=17). Depressive symptoms were measured at each visit using the Inventory of Depressive Symptoms-Clinician Rating (IDS-C) and the Multidimensional Fatigue Inventory. IFN-alpha was associated with a significant increase in Glu/Cr in dACC and left basal ganglia. Increases in dACC Glu/Cr were positively correlated with scores on the IDS-C in the group as a whole, but not in either group alone. Glu/Cr increases in left basal ganglia were correlated with decreased motivation in the group as a whole and in IFN-alpha-treated subjects alone. No Glu/Cr changes were found in the right basal ganglia, and no significant correlations were found between Glu/Cr and the inflammatory markers. IFN-alpha-induced increases in glutamate in dACC and basal ganglia are consistent with MRS findings in bipolar depression and suggest that inflammatory cytokines may contribute to glutamate alterations in patients with mood disorders and increased inflammation. PMID:24481242

  18. Ablation of Type-1 IFN Signaling in Hematopoietic Cells Confers Protection Following Traumatic Brain Injury123

    PubMed Central

    Karve, Ila P.; Zhang, Moses; Habgood, Mark; Frugier, Tony; Brody, Kate M.; Sashindranath, Maithili; Ek, C. Joakim; Kile, Ben T.; Wright, David; Wang, Hong; Johnston, Leigh; Daglas, Maria; Ates, Robert C.; Medcalf, Robert L.; Taylor, Juliet M.

    2016-01-01

    Abstract Type-1 interferons (IFNs) are pleiotropic cytokines that signal through the type-1 IFN receptor (IFNAR1). Recent literature has implicated the type-1 IFNs in disorders of the CNS. In this study, we have investigated the role of type-1 IFNs in neuroinflammation following traumatic brain injury (TBI). Using a controlled cortical impact model, TBI was induced in 8- to 10-week-old male C57BL/6J WT and IFNAR1−/− mice and brains were excised to study infarct volume, inflammatory mediator release via quantitative PCR analysis and immune cell profile via immunohistochemistry. IFNAR1−/− mice displayed smaller infarcts compared with WT mice after TBI. IFNAR1−/− mice exhibited an altered anti-inflammatory environment compared with WT mice, with significantly reduced levels of the proinflammatory mediators TNFα, IL-1β and IL-6, an up-regulation of the anti-inflammatory mediator IL-10 and an increased activation of resident and peripheral immune cells after TBI. WT mice injected intravenously with an anti-IFNAR1 blocking monoclonal antibody (MAR1) 1 h before, 30 min after or 30 min and 2 d after TBI displayed significantly improved histological and behavioral outcome. Bone marrow chimeras demonstrated that the hematopoietic cells are a peripheral source of type-1 IFNs that drives neuroinflammation and a worsened TBI outcome. Type-1 IFN mRNA levels were confirmed to be significantly altered in human postmortem TBI brains. Together, these data demonstrate that type-1 IFN signaling is a critical pathway in the progression of neuroinflammation and presents a viable therapeutic target for the treatment of TBI. PMID:27022620

  19. Host Susceptibility to Brucella abortus Infection Is More Pronounced in IFN-γ knockout than IL-12/β2-Microglobulin Double-Deficient Mice

    PubMed Central

    Brandão, Ana Paula M. S.; Oliveira, Fernanda S.; Carvalho, Natalia B.; Vieira, Leda Q.; Azevedo, Vasco; Macedo, Gilson C.; Oliveira, Sergio C.

    2012-01-01

    Brucella abortus is a facultative intracellular bacterial pathogen that causes abortion in domestic animals and undulant fever in humans. IFN-γ, IL-12, and CD8+ T lymphocytes are important components of host immune responses against B. abortus. Herein, IFN-γ and IL-12/β2-microglobulin (β2-m) knockout mice were used to determine whether CD8+ T cells and IL-12-dependent IFN-γ deficiency would be more critical to control B. abortus infection compared to the lack of endogenous IFN-γ. At 1 week after infection, IFN-γ KO and IL-12/β2-m KO mice showed increased numbers of bacterial load in spleens; however, at 3 weeks postinfection (p.i.), only IFN-γ KO succumbed to Brucella. All IFN-γ KO had died at 16 days p.i. whereas death within the IL-12/β2-m KO group was delayed and occurred at 32 days until 47 days postinfection. Susceptibility of IL-12/β2-m KO animals to Brucella was associated to undetectable levels of IFN-γ in mouse splenocytes and inability of these cells to lyse Brucella-infected macrophages. However, the lack of endogenous IFN-γ was found to be more important to control brucellosis than CD8+ T cells and IL-12-dependent IFN-γ deficiencies. PMID:22194770

  20. Role of IFN-γ and IL-6 cytokines and their association in determining susceptibility to chronic idiopathic urticaria.

    PubMed

    Alasandagutti, Madhavi Latha; Ponnana, Meenakshi; Sivangala, Ramya; Thada, Shruthi; Joshi, Lavanya; Hussain, Hidayath; Ansari, Soheb Sadath; Valluri, Vijayalakshmi; Gaddam, Suman Latha

    2014-12-01

    Chronic Idiopathic Urticaria (CIU) is a common skin disorder, which may occur spontaneously. The aim of the present study was to assess the serum levels of interferon (IFN)-γ and interleukin (IL)-6 and to examine the association of IFN-γ+874 T/A and IL-6-174 G/C cytokine gene polymorphisms. To accomplish this, ELISA-based cytokine serum levels of IFN-γ (n=30) and IL-6 (n=30) in CIU patients (n=100) and Healthy Controls (HC) (n=200) were performed. Amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) was performed to verify the positional significance. A significant (p<0.0001) increase in the serum cytokine levels of IFN-γ and IL-6 was recorded in CIU patients compared to HC. The AT and TT genotypes of IFN-γ and GG genotype of IL-6 were found to be significantly associated with CIU. In conclusion, our findings show a significant increase in the cytokine levels of IFN-γ and IL-6, highlighting their regulatory role in the development of disease. In addition to this, association studies have revealed that TT genotype of IFN-γ +874 T/A and GG genotype of IL-6-174 G/C were susceptible towards the CIU. PMID:25409241

  1. Sex Differences in Plasmacytoid Dendritic Cell Levels of IRF5 Drive Higher IFN-α Production in Women

    PubMed Central

    Griesbeck, Morgane; Ziegler, Susanne; Laffont, Sophie; Smith, Nikaïa; Chauveau, Lise; Tomezsko, Phillip; Sharei, Armon; Kourjian, Georgio; Porichis, Filippos; Hart, Meghan; Palmer, Christine D.; Sirignano, Michael; Beisel, Claudia; Hildebrandt, Heike; Cénac, Claire; Villani, Alexandra-Chloé; Diefenbach, Thomas J.; Le Gall, Sylvie; Schwartz, Olivier; Herbeuval, Jean-Philippe; Autran, Brigitte; Guéry, Jean-Charles; Chang, J. Judy

    2015-01-01

    Increased IFN-α production contributes to the pathogenesis of infectious and autoimmune diseases. Plasmacytoid dendritic cells (pDCs) from females produce more IFN-α upon TLR7 stimulation than pDCs from males, yet the mechanisms underlying this difference remain unclear. In this article, we show that basal levels of IFN regulatory factor (IRF) 5 in pDCs were significantly higher in females compared with males and positively correlated with the percentage of IFN-α–secreting pDCs. Delivery of recombinant IRF5 protein into human primary pDCs increased TLR7-mediated IFN-α secretion. In mice, genetic ablation of the estrogen receptor 1 (Esr1) gene in the hematopoietic compartment or DC lineage reduced Irf5 mRNA expression in pDCs and IFN-α production. IRF5 mRNA levels furthermore correlated with ESR1 mRNA levels in human pDCs, consistent with IRF5 regulation at the transcriptional level by ESR1. Taken together, these data demonstrate a critical mechanism by which sex differences in basal pDC IRF5 expression lead to higher IFN-α production upon TLR7 stimulation in females and provide novel targets for the modulation of immune responses and inflammation. PMID:26519527

  2. Sex Differences in Plasmacytoid Dendritic Cell Levels of IRF5 Drive Higher IFN-α Production in Women.

    PubMed

    Griesbeck, Morgane; Ziegler, Susanne; Laffont, Sophie; Smith, Nikaïa; Chauveau, Lise; Tomezsko, Phillip; Sharei, Armon; Kourjian, Georgio; Porichis, Filippos; Hart, Meghan; Palmer, Christine D; Sirignano, Michael; Beisel, Claudia; Hildebrandt, Heike; Cénac, Claire; Villani, Alexandra-Chloé; Diefenbach, Thomas J; Le Gall, Sylvie; Schwartz, Olivier; Herbeuval, Jean-Philippe; Autran, Brigitte; Guéry, Jean-Charles; Chang, J Judy; Altfeld, Marcus

    2015-12-01

    Increased IFN-α production contributes to the pathogenesis of infectious and autoimmune diseases. Plasmacytoid dendritic cells (pDCs) from females produce more IFN-α upon TLR7 stimulation than pDCs from males, yet the mechanisms underlying this difference remain unclear. In this article, we show that basal levels of IFN regulatory factor (IRF) 5 in pDCs were significantly higher in females compared with males and positively correlated with the percentage of IFN-α-secreting pDCs. Delivery of recombinant IRF5 protein into human primary pDCs increased TLR7-mediated IFN-α secretion. In mice, genetic ablation of the estrogen receptor 1 (Esr1) gene in the hematopoietic compartment or DC lineage reduced Irf5 mRNA expression in pDCs and IFN-α production. IRF5 mRNA levels furthermore correlated with ESR1 mRNA levels in human pDCs, consistent with IRF5 regulation at the transcriptional level by ESR1. Taken together, these data demonstrate a critical mechanism by which sex differences in basal pDC IRF5 expression lead to higher IFN-α production upon TLR7 stimulation in females and provide novel targets for the modulation of immune responses and inflammation. PMID:26519527

  3. Contraction of the type I IFN locus and unusual constitutive expression of IFN-α in bats

    PubMed Central

    Zhou, Peng; Tachedjian, Mary; Wynne, James W.; Boyd, Victoria; Smith, Ina; Cowled, Christopher; Ng, Justin H. J.; Mok, Lawrence; Michalski, Wojtek P.; Mendenhall, Ian H.; Tachedjian, Gilda; Baker, Michelle L.

    2016-01-01

    Bats harbor many emerging and reemerging viruses, several of which are highly pathogenic in other mammals but cause no clinical signs of disease in bats. To determine the role of interferons (IFNs) in the ability of bats to coexist with viruses, we sequenced the type I IFN locus of the Australian black flying fox, Pteropus alecto, providing what is, to our knowledge, the first gene map of the IFN region of any bat species. Our results reveal a highly contracted type I IFN family consisting of only 10 IFNs, including three functional IFN-α loci. Furthermore, the three IFN-α genes are constitutively expressed in unstimulated bat tissues and cells and their expression is unaffected by viral infection. Constitutively expressed IFN-α results in the induction of a subset of IFN-stimulated genes associated with antiviral activity and resistance to DNA damage, providing evidence for a unique IFN system that may be linked to the ability of bats to coexist with viruses. PMID:26903655

  4. Contraction of the type I IFN locus and unusual constitutive expression of IFN-α in bats.

    PubMed

    Zhou, Peng; Tachedjian, Mary; Wynne, James W; Boyd, Victoria; Cui, Jie; Smith, Ina; Cowled, Christopher; Ng, Justin H J; Mok, Lawrence; Michalski, Wojtek P; Mendenhall, Ian H; Tachedjian, Gilda; Wang, Lin-Fa; Baker, Michelle L

    2016-03-01

    Bats harbor many emerging and reemerging viruses, several of which are highly pathogenic in other mammals but cause no clinical signs of disease in bats. To determine the role of interferons (IFNs) in the ability of bats to coexist with viruses, we sequenced the type I IFN locus of the Australian black flying fox, Pteropus alecto, providing what is, to our knowledge, the first gene map of the IFN region of any bat species. Our results reveal a highly contracted type I IFN family consisting of only 10 IFNs, including three functional IFN-α loci. Furthermore, the three IFN-α genes are constitutively expressed in unstimulated bat tissues and cells and their expression is unaffected by viral infection. Constitutively expressed IFN-α results in the induction of a subset of IFN-stimulated genes associated with antiviral activity and resistance to DNA damage, providing evidence for a unique IFN system that may be linked to the ability of bats to coexist with viruses. PMID:26903655

  5. A distal locus element mediates IFN-γ priming of LPS-stimulated TNF gene expression

    PubMed Central

    Chow, Nancy A.; Jasenosky, Luke D.; Goldfeld, Anne E.

    2014-01-01

    SUMMARY IFN-γ priming sensitizes monocytes/macrophages to lipopolysaccharide (LPS) stimulation, resulting in augmented expression of a set of genes including TNF. Here, we demonstrate that IFN-γ priming of LPS-stimulated TNF transcription requires a distal TNF/LT locus element 8 kb upstream of the TNF transcription start site (hHS-8). IFN-γ stimulation leads to increased DNase I accessibility of hHS-8 and its recruitment of IRF1, and subsequent LPS stimulation enhances H3K27 acetylation and induces enhancer RNA synthesis at hHS-8. Ablation of IRF1 or targeting the hHS-8 IRF1 binding site in vivo with Cas9 linked to the KRAB repressive domain abolishes IFN-γ priming while LPS induction of the gene is unaffected. Thus, IFN-γ poises a distal enhancer in the TNF/LT locus by chromatin remodeling and IRF1 recruitment, which then drives enhanced TNF gene expression in response to a secondary TLR stimulus. PMID:25482561

  6. Preparation and characterization of latex films photo-immobilized with IFN-α.

    PubMed

    Wu, Lifang; Hu, Kaikai; Zhang, Li; Chen, Wuya; Chen, Xiaohui; You, Rong; Yin, Liang; Guan, Yan-Qing

    2016-09-01

    We developed a biomaterial by photo-immobilizing interferon-α (IFN-α) on the surface of latex condom films for the prevention and treatment of cervicitis, cervical cancers and diseases caused by cervical virus. The IFN-α modification by photoactive N-(4-azidobenzoyloxy) succinimide was characterized on a nano-scale by spectroscopy analysis and micro morphology. The anti-bacterial, anti-cancer, and anti-viral effects of the modified bioactive latex films were evaluated by antibacterial susceptibility testing, Gram staining, flow cytometry, immunofluorescence, and Western blotting. Our results showed that the photo-immobilized IFN-α latex films effectively inhibited the growth of both Neisseria gonorrhoeae and human cervical cancer HeLa cells. Moreover, the expression of anti-viral proteins, including P56, MxA, and 2', 5'-OAS, in the human cervical epithelial cell line NC104 was significantly increased by photo-immobilized IFN-α latex films. Taken together, these results suggest that photo-immobilized IFN-α latex films may have therapeutic effects against cervicitis, cervical cancers, and cervical virus. PMID:27137809

  7. HBsAg blocks TYPE I IFN induced up-regulation of A3G through inhibition of STAT3.

    PubMed

    Xu, Fengchao; Song, Hongxiao; Li, Na; Tan, Guangyun

    2016-04-22

    Interferon (IFN) is a regularly utilized therapeutic for the treatment of chronic hepatitis B and appears to induce superior HBeAg seroconversion comparing nucleos/tide analogs. However, the mechanisms underlying IFN inhibition of HBV replication, as well as poor responses to IFN are unclear. Apobec3G has been reported to be involved in regulating HBV replication. In this study, we investigated Apobec3G expression and regulatory pathways during HBV infection. We show that over-expression of A3G leads to inhibition of HBV replication. We also show that IFN induces a significant increase in A3G protein expression, which is associated with STAT3 activation. We further show that A3G expression in HBV patients is lower compared to non-infected controls, possibly by HBsAg which inhibits IFN induced A3G up-regulation in a dose dependent manner. This process is likely mediated through inhibition of STAT3-Ser727 phosphorylation. The results presented in this study indicate that STAT3 plays an important role in IFN-induced A3G production, and HBsAg may correlated with poor response to IFN treatment. PMID:27003258

  8. Role of Baicalin in Anti-Influenza Virus A as a Potent Inducer of IFN-Gamma

    PubMed Central

    Chu, Ming; Xu, Lan; Zhang, Ming-bo; Chu, Zheng-yun; Wang, Yue-dan

    2015-01-01

    Baicalin (BA) is a flavonoid compound purified from Scutellaria baicalensis Georgi and has been shown to possess a potent inhibitory activity against viruses. However, the role of BA in anti-influenza virus has not been extensively studied, and the immunological mechanism of BA in antiviral activity remains unknown. Here, we observed that BA could protect mice from infection by influenza virus A/PR/8/34 (H1N1), associated with increasing IFN-γ production, but presented no effects in IFN-γ or IFN-γ receptor deficient mice. Further study indicated that BA could inhibit A/PR/8/34 replication through IFN-γ in human PBMC. Moreover, BA can directly induce IFN-γ production in human CD4+ and CD8+ T cells and NK cells, and activate JAK/STAT-1 signaling pathway. Collectively, BA exhibited anti-influenza virus A (H1N1) activity in vitro and in vivo as a potent inducer of IFN-γ in major IFN-γ producing cells. PMID:26783516

  9. IFN-λ receptor 1 expression is induced in chronic hepatitis C and correlates with the IFN-λ3 genotype and with nonresponsiveness to IFN-α therapies

    PubMed Central

    Duong, Francois H.T.; Trincucci, Gaia; Boldanova, Tujana; Calabrese, Diego; Campana, Benedetta; Krol, Ilona; Durand, Sarah C.; Heydmann, Laura; Zeisel, Mirjam B.; Baumert, Thomas F.

    2014-01-01

    The molecular mechanisms that link IFN-λ3 genotypes to differential induction of interferon (IFN)-stimulated genes (ISGs) in the liver of patients with chronic hepatitis C (CHC) are not known. We measured the expression of IFN-λ and of the specific IFN-λ receptor chain (IFN-λR1) in 122 liver biopsies of patients with CHC and 53 control samples. The IFN-λ3 genotype was not associated with differential expression of IFN-λ, but rather IFN-λR1. In a series of 30 primary human hepatocyte (PHH) samples, IFN-λR1 expression was low but could be induced with IFN-α. IFN-α–induced IFN-λR1 expression was significantly stronger in PHHs carrying the minor IFN-λ3 allele. The analysis of liver biopsies of patients with CHC revealed a strong association of high IFN-λR1 expression with elevated ISG expression, with IFN-λ3 minor alleles, and with nonresponse to pegylated IFN-α and ribavirin. The findings provide a missing link between the IFN-λ3 genotype and the associated phenotype of treatment nonresponse. PMID:24752298

  10. IFN-λ receptor 1 expression is induced in chronic hepatitis C and correlates with the IFN-λ3 genotype and with nonresponsiveness to IFN-α therapies.

    PubMed

    Duong, Francois H T; Trincucci, Gaia; Boldanova, Tujana; Calabrese, Diego; Campana, Benedetta; Krol, Ilona; Durand, Sarah C; Heydmann, Laura; Zeisel, Mirjam B; Baumert, Thomas F; Heim, Markus H

    2014-05-01

    The molecular mechanisms that link IFN-λ3 genotypes to differential induction of interferon (IFN)-stimulated genes (ISGs) in the liver of patients with chronic hepatitis C (CHC) are not known. We measured the expression of IFN-λ and of the specific IFN-λ receptor chain (IFN-λR1) in 122 liver biopsies of patients with CHC and 53 control samples. The IFN-λ3 genotype was not associated with differential expression of IFN-λ, but rather IFN-λR1. In a series of 30 primary human hepatocyte (PHH) samples, IFN-λR1 expression was low but could be induced with IFN-α. IFN-α-induced IFN-λR1 expression was significantly stronger in PHHs carrying the minor IFN-λ3 allele. The analysis of liver biopsies of patients with CHC revealed a strong association of high IFN-λR1 expression with elevated ISG expression, with IFN-λ3 minor alleles, and with nonresponse to pegylated IFN-α and ribavirin. The findings provide a missing link between the IFN-λ3 genotype and the associated phenotype of treatment nonresponse. PMID:24752298

  11. Polo-like Kinase 1 (PLK1) Regulates Interferon (IFN) Induction by MAVS*

    PubMed Central

    Vitour, Damien; Dabo, Stéphanie; Ahmadi Pour, Malek; Vilasco, Myriam; Vidalain, Pierre-Olivier; Jacob, Yves; Mezel-Lemoine, Mariana; Paz, Suzanne; Arguello, Meztli; Lin, Rongtuan; Tangy, Frédéric; Hiscott, John; Meurs, Eliane F.

    2009-01-01

    The mitochondria-bound adapter MAVS participates in IFN induction by recruitment of downstream partners such as members of the TRAF family, leading to activation of NF-κB, and the IRF3 pathways. A yeast two-hybrid search for MAVS-interacting proteins yielded the Polo-box domain (PBD) of the mitotic Polo-like kinase PLK1. We showed that PBD associates with two different domains of MAVS in both dependent and independent phosphorylation events. The phosphodependent association requires the phosphopeptide binding ability of PBD. It takes place downstream of the proline-rich domain of MAVS, within an STP motif, characteristic of the binding of PLK1 to its targets, where the central Thr234 residue is phosphorylated. Its phosphoindependent association takes place at the C terminus of MAVS. PLK1 strongly inhibits the ability of MAVS to activate the IRF3 and NF-κB pathways and to induce IFN. Reciprocally, depletion of PLK1 can increase IFN induction in response to RIG-I/SeV or RIG-I/poly(I)-poly(C) treatments. This inhibition is dependent on the phosphoindependent association of PBD at the C terminus of MAVS where it disrupts the association of MAVS with its downstream partner TRAF3. IFN induction was strongly inhibited in cells arrested in G2/M by nocodazole, which provokes increased expression of endogenous PLK1. Interestingly, depletion of PLK1 from these nocodazole-treated cells could restore, at least partially, IFN induction. Altogether, these data demonstrate a new function for PLK1 as a regulator of IFN induction and provide the basis for the development of inhibitors preventing the PLK1/MAVS association to sustain innate immunity. PMID:19546225

  12. Phosphatase PP4 Negatively Regulates Type I IFN Production and Antiviral Innate Immunity by Dephosphorylating and Deactivating TBK1.

    PubMed

    Zhan, Zhenzhen; Cao, Hao; Xie, Xuefeng; Yang, Linshan; Zhang, Peng; Chen, Yihan; Fan, Huimin; Liu, Zhongmin; Liu, Xingguang

    2015-10-15

    The effective recognition of viral infection and subsequent type I IFN production is essential for the host antiviral innate immune responses. The phosphorylation and activation of kinase TANK-binding kinase 1 (TBK1) plays crucial roles in the production of type I IFN mediated by TLR and retinoic acid-inducible gene I-like receptors. Type I IFN expression must be tightly regulated to prevent the development of immunopathological disorders. However, how the activated TBK1 is negatively regulated by phosphatases remains poorly understood. In this study, we identified a previously unknown role of protein phosphatase (PP)4 by acting as a TBK1 phosphatase. PP4 expression was upregulated in macrophages infected with RNA virus, vesicular stomatitis virus, and Sendai virus in vitro and in vivo. Knockdown of PP4C, the catalytic subunit of PP4, significantly increased type I IFN production in macrophages and dentritic cells triggered by TLR3/4 ligands, vesicular stomatitis virus, and Sendai virus, and thus inhibited virus replication. Similar results were also found in peritoneal macrophages with PP4C silencing in vivo and i.p. infection of RNA virus. Accordingly, ectopic expression of PP4C inhibited virus-induced type I IFN production and promoted virus replication. However, overexpression of a phosphatase-dead PP4C mutant abolished the inhibitory effects of wild-type PP4C on type I IFN production. Mechanistically, PP4 directly bound TBK1 upon virus infection, then dephosphorylated TBK1 at Ser(172) and inhibited TBK1 activation, and subsequently restrained IFN regulatory factor 3 activation, resulting in suppressed production of type I IFN and IFN-stimulated genes. Thus, serine/threonine phosphatase PP4 functions as a novel feedback negative regulator of RNA virus-triggered innate immunity. PMID:26363053

  13. Examination of the mechanism by which heparin antagonizes activation of a model endothelium by interferon-gamma (IFN-γ)

    PubMed Central

    DOUGLAS, M S; RIX, D A; DARK, J H; TALBOT, D; KIRBY, J A

    1997-01-01

    IFNincreases the potential immunogenicity of vascular endothelial cells by up-regulation of intercellular adhesion molecule-1 (ICAM-1) and class I MHC antigen expression and by induction of class II MHC antigens and certain chemokines. In this study the mechanism by which the glycosaminoglycan (GAG) heparin antagonizes the activation of a model endothelium by IFN-γ was investigated. Radioligand binding assays demonstrated that total binding of 125I-IFN-γ to the EAhy.926 endothelial hybridoma cell line was reduced in the presence of heparin or heparan sulphate (HS); the structurally dissimilar GAG chondroitin sulphate had no effect. Treatment of the cells with chlorate, a metabolic inhibitor of GAG sulphation, was found to reduce both the subsequent binding of IFN-γ and its ability to induce expression of class II MHC antigens. Treatment with heparinase II dramatically reduced the binding of IFN-γ, while chondroitin ABC lyase had no effect. A cationic peptide from the C-terminal region of IFN-γ was also found to reduce binding of intact IFN-γ to the cells. These results appear to demonstrate that IFN-γ is sequestered at the surface of endothelial cells by electrostatic interaction between specific basic amino acid residues and sulphated domains on HS, the most abundant endothelial GAG. This interaction is competitively inhibited by heparin, which is structurally related to HS. These observations are consistent with the model that IFN-γ is bound by membrane-associated HS before engagement with the high-affinity receptor and signal transduction. Inhibition of the interaction between proinflammatory cytokines and membrane-associated GAG molecules may provide a mechanism for inducing clinically useful immunosuppression. PMID:9067536

  14. Examination of the mechanism by which heparin antagonizes activation of a model endothelium by interferon-gamma (IFN-gamma).

    PubMed

    Douglas, M S; Rix, D A; Dark, J H; Talbot, D; Kirby, J A

    1997-03-01

    IFN-gamma increases the potential immunogenicity of vascular endothelial cells by up-regulation of intercellular adhesion molecule-1 (ICAM-1) and class I MHC antigen expression and by induction of class II MHC antigens and certain chemokines. In this study the mechanism by which the glycosaminoglycan (GAG) heparin antagonizes the activation of a model endothelium by IFN-gamma was investigated. Radioligand binding assays demonstrated that total binding of 125I-IFN-gamma to the EAhy.926 endothelial hybridoma cell line was reduced in the presence of heparin or heparan sulphate (HS); the structurally dissimilar GAG chondroitin sulphate had no effect. Treatment of the cells with chlorate, a metabolic inhibitor of GAG sulphation, was found to reduce both the subsequent binding of IFN-gamma and its ability to induce expression of class II MHC antigens. Treatment with heparinase II dramatically reduced the binding of IFN-gamma, while chondroitin ABC lyase had no effect. A cationic peptide from the C-terminal region of IFN-gamma was also found to reduce binding of intact IFN-gamma to the cells. These results appear to demonstrate that IFN-gamma is sequestered at the surface of endothelial cells by electrostatic interaction between specific basic amino acid residues and sulphated domains on HS, the most abundant endothelial GAG. This interaction is competitively inhibited by heparin, which is structurally related to HS. These observations are consistent with the model that IFN-gamma is bound by membrane-associated HS before engagement with the high-affinity receptor and signal transduction. Inhibition of the interaction between proinflammatory cytokines and membrane-associated GAG molecules may provide a mechanism for inducing clinically useful immunosuppression. PMID:9067536

  15. Calcium ionophore and phorbol ester activation of proliferation and. gamma. -IFN production by neonatal mononuclear cells (MNCs)

    SciTech Connect

    Bryson, Y.J.; Kuhls, T.L.; Pineda, E.

    1986-03-01

    Human neonatal MNCs have a dissociation between prolif. and ..gamma..-IFN prod. Although cord MNCs display normal-high prolif. following lectin stim., ..gamma..-IFN prod. is greatly diminished compared to adult MNCs. Increasing data support a 2-stimuli requirement for human T-cell activation as noted in the T-cell line Jurkat as well as in peripheral T-cells. They have compared prolif. and ..gamma..-IFN responses of cord and adult MNCs to the calcium ionophore A23187, phorbol myristate acetate (PMA), PHA and their combinations. Cord and adult MNCs had similar prolif. responses to A23187, PMA and PHA. PMA alone acted as a weak mitogen compared to PHA. Optimal A23187 alone caused very low amts of prolif. Either PMA or A23187 suppressed PHA-stim. prolif. while A23187 augmented PMA-induced prolif. A23187, PMA or PHA alone prod. ..gamma..-IFN in adult but not cord MNCs. The addition of PMA or A23187 augmented the PHA-induced ..gamma..-IFN prod. in both cord and adult MNCs (6..-->..80 IU vs 240..-->..480 IU resp). When combined, A23187 and PMA stim. optimal and comparable amts of ..gamma..-IFN in adult and cord MNCs (480 IU). From these findings they conclude that although the stimuli for ..gamma..-IFN and prolif. may be similar, there is an absolute requirement for 2 stimuli (PMA/A23187) for ..gamma..-IFN prod. by cord cells and optimal prod. in adult MNCs. The defect of ..gamma..-IFN prod. observed in PHA stim. neonatal MNCs can be corrected using a calcium ionophore and protein kinase C activator.

  16. Andrographolide Restores Steroid Sensitivity To Block Lipopolysaccharide/IFN-γ-Induced IL-27 and Airway Hyperresponsiveness in Mice.

    PubMed

    Liao, Wupeng; Tan, W S Daniel; Wong, W S Fred

    2016-06-01

    LPS and IFN-γ alone or in combination have been implicated in the development of steroid resistance. Combined LPS/IFN-γ strongly upregulates IL-27 production, which has been linked to steroid-resistant airway hyperresponsiveness (AHR). Andrographolide, a bioactive molecule isolated from the plant Andrographis paniculata, has demonstrated anti-inflammatory and antioxidant properties. The present study investigated whether andrographolide could restore steroid sensitivity to block LPS/IFN-γ-induced IL-27 production and AHR via its antioxidative property. The mouse macrophage cell line Raw 264.7, mouse primary lung monocytes/macrophages, and BALB/c mice were treated with LPS/IFN-γ, in the presence and absence of dexamethasone and/or andrographolide. Levels of IL-27 in vitro and in vivo were examined and mouse AHR was assessed. Dexamethasone alone failed to inhibit LPS/IFN-γ-induced IL-27 production and AHR in mice. Andrographolide significantly restored the suppressive effect of dexamethasone on LPS/IFN-γ-induced IL-27 mRNA and protein levels in the macrophage cell line and primary lung monocytes/macrophages, mouse bronchoalveolar lavage fluid and lung tissues, and AHR in mice. LPS/IFN-γ markedly reduced the nuclear level of histone deacetylase (HDAC)2, an essential epigenetic enzyme that mediates steroid anti-inflammatory action. LPS/IFN-γ also decreased total HDAC activity but increased the total histone acetyltransferase/HDAC activity ratio in mouse lungs. Andrographolide significantly restored nuclear HDAC2 protein levels and total HDAC activity, and it diminished the total histone acetyltransferase/HDAC activity ratio in mouse lungs exposed to LPS/IFN-γ, possibly via suppression of PI3K/Akt/HDAC2 phosphorylation, and upregulation of the antioxidant transcription factor NF erythroid-2-related factor 2 level and DNA binding activity. Our data suggest that andrographolide may have therapeutic value in resensitizing steroid action in respiratory disorders

  17. Melanoma NOS1 expression promotes dysfunctional IFN signaling

    PubMed Central

    Liu, Qiuzhen; Tomei, Sara; Ascierto, Maria Libera; De Giorgi, Valeria; Bedognetti, Davide; Dai, Cuilian; Uccellini, Lorenzo; Spivey, Tara; Pos, Zoltan; Thomas, Jaime; Reinboth, Jennifer; Murtas, Daniela; Zhang, Qianbing; Chouchane, Lotfi; Weiss, Geoffrey R.; Slingluff, Craig L.; Lee, Peter P.; Rosenberg, Steven A.; Alter, Harvey; Yao, Kaitai; Wang, Ena; Marincola, Francesco M.

    2014-01-01

    In multiple forms of cancer, constitutive activation of type I IFN signaling is a critical consequence of immune surveillance against cancer; however, PBMCs isolated from cancer patients exhibit depressed STAT1 phosphorylation in response to IFN-α, suggesting IFN signaling dysfunction. Here, we demonstrated in a coculture system that melanoma cells differentially impairs the IFN-α response in PBMCs and that the inhibitory potential of a particular melanoma cell correlates with NOS1 expression. Comparison of gene transcription and array comparative genomic hybridization (aCGH) between melanoma cells from different patients indicated that suppression of IFN-α signaling correlates with an amplification of the NOS1 locus within segment 12q22-24. Evaluation of NOS1 levels in melanomas and IFN responsiveness of purified PBMCs from patients indicated a negative correlation between NOS1 expression in melanomas and the responsiveness of PBMCs to IFN-α. Furthermore, in an explorative study, NOS1 expression in melanoma metastases was negatively associated with patient response to adoptive T cell therapy. This study provides a link between cancer cell phenotype and IFN signal dysfunction in circulating immune cells. PMID:24691438

  18. IL-12 enhances the antitumor actions of trastuzumab via NK cell IFN-γ production.

    PubMed

    Jaime-Ramirez, Alena Cristina; Mundy-Bosse, Bethany L; Kondadasula, SriVidya; Jones, Natalie B; Roda, Julie M; Mani, Aruna; Parihar, Robin; Karpa, Volodymyr; Papenfuss, Tracey L; LaPerle, Krista M; Biller, Elizabeth; Lehman, Amy; Chaudhury, Abhik Ray; Jarjoura, David; Burry, Richard W; Carson, William E

    2011-03-15

    The antitumor effects of therapeutic mAbs may depend on immune effector cells that express FcRs for IgG. IL-12 is a cytokine that stimulates IFN-γ production from NK cells and T cells. We hypothesized that coadministration of IL-12 with a murine anti-HER2/neu mAb (4D5) would enhance the FcR-dependent immune mechanisms that contribute to its antitumor activity. Thrice-weekly therapy with IL-12 (1 μg) and 4D5 (1 mg/kg) significantly suppressed the growth of a murine colon adenocarcinoma that was engineered to express human HER2 (CT-26(HER2/neu)) in BALB/c mice compared with the result of therapy with IL-12, 4D5, or PBS alone. Combination therapy was associated with increased circulating levels of IFN-γ, monokine induced by IFN-γ, and RANTES. Experiments with IFN-γ-deficient mice demonstrated that this cytokine was necessary for the observed antitumor effects of therapy with IL-12 plus 4D5. Immune cell depletion experiments showed that NK cells (but not CD4(+) or CD8(+) T cells) mediated the antitumor effects of this treatment combination. Therapy of HER2/neu-positive tumors with trastuzumab plus IL-12 induced tumor necrosis but did not affect tumor proliferation, apoptosis, vascularity, or lymphocyte infiltration. In vitro experiments with CT-26(HER2/neu) tumor cells revealed that IFN-γ induced an intracellular signal but did not inhibit cellular proliferation or induce apoptosis. Taken together, these data suggest that tumor regression in response to trastuzumab plus IL-12 is mediated through NK cell IFN-γ production and provide a rationale for the coadministration of NK cell-activating cytokines with therapeutic mAbs. PMID:21321106

  19. Identification of an IFN-γ/mast cell axis in a mouse model of chronic asthma

    PubMed Central

    Yu, Mang; Eckart, Michael R.; Morgan, Alexander A.; Mukai, Kaori; Butte, Atul J.; Tsai, Mindy; Galli, Stephen J.

    2011-01-01

    Asthma is considered a Th2 cell–associated disorder. Despite this, both the Th1 cell–associated cytokine IFN-γ and airway neutrophilia have been implicated in severe asthma. To investigate the relative contributions of different immune system components to the pathogenesis of asthma, we previously developed a model that exhibits several features of severe asthma in humans, including airway neutrophilia and increased lung IFN-γ. In the present studies, we tested the hypothesis that IFN-γ regulates mast cell function in our model of chronic asthma. Engraftment of mast cell–deficient KitW-sh/W-sh mice, which develop markedly attenuated features of disease, with wild-type mast cells restored disease pathology in this model of chronic asthma. However, disease pathology was not fully restored by engraftment with either IFN-γ receptor 1–null (Ifngr1–/–) or Fcε receptor 1γ–null (Fcer1g–/–) mast cells. Additional analysis, including gene array studies, showed that mast cell expression of IFN-γR contributed to the development of many FcεRIγ-dependent and some FcεRIγ-independent features of disease in our model, including airway hyperresponsiveness, neutrophilic and eosinophilic inflammation, airway remodeling, and lung expression of several cytokines, chemokines, and markers of an alternatively activated macrophage response. These findings identify a previously unsuspected IFN-γ/mast cell axis in the pathology of chronic allergic inflammation of the airways in mice. PMID:21737883

  20. Enrichment of IFN-γ producing cells in different murine adipose tissue depots upon infection with an apicomplexan parasite

    PubMed Central

    Teixeira, Luzia; Marques, Raquel M.; Ferreirinha, Pedro; Bezerra, Filipa; Melo, Joana; Moreira, João; Pinto, Ana; Correia, Alexandra; Ferreira, Paula G.; Vilanova, Manuel

    2016-01-01

    Here we report that lean mice infected with the intracellular parasite Neospora caninum show a fast but sustained increase in the frequency of IFN-γ-producing cells noticeable in distinct adipose tissue depots. Moreover, IFN-γ-mediated immune memory could be evoked in vitro in parasite antigen-stimulated adipose tissue stromal vascular fraction cells collected from mice infected one year before. Innate or innate-like cells such as NK, NK T and TCRγδ+ cells, but also CD4+ and CD8+ TCRβ+ lymphocytes contributed to the IFN-γ production observed since day one of infection. This early cytokine production was largely abrogated in IL-12/IL23 p40-deficient mice. Moreover, production of IFN-γ by stromal vascular fraction cells isolated from these mice was markedly lower than that of wild-type counterparts upon stimulation with parasite antigen. In wild-type mice the increased IFN-γ production was concomitant with up-regulated expression of genes encoding interferon-inducible GTPases and nitric oxide synthase, which are important effector molecules in controlling intracellular parasite growth. This increased gene expression was markedly impaired in the p40-deficient mice. Overall, these results show that NK cells but also diverse T cell populations mediate a prompt and widespread production of IFN-γ in the adipose tissue of N. caninum infected mice. PMID:27001522

  1. Neutralizing Antibodies against IFN-[Beta] in Multiple Sclerosis: Antagonization of IFN-[Beta] Mediated Suppression of MMPs

    ERIC Educational Resources Information Center

    Gilli, Francesca; Bertolotto, Antonio; Sala, Arianna; Hoffmann, Francine; Capobianco, Marco; Malucchi, Simona; Glass, Tracy; Kappos, Ludwig; Lindberg, Raija L. P.; Leppert, David

    2004-01-01

    Neutralizing antibodies (NAb) against interferon-[Beta] (IFN-Beta) develop in about a third of treated multiple sclerosis patients and are believed to reduce therapeutic efficacy of IFN-[Beta] on clinical and MRI measures. The expression of the interferon acute-response protein, myxovirus resistance protein A (MxA) is a sensitive measure of the…

  2. Ectoplacental cone induces resistance to apoptosis in high doses of interferon (IFN)-γ-treated decidual cells.

    PubMed

    Borbely, Alexandre U; Fontenele-Neto, José D; Vidsiunas, Alex K; Gomes, Sara Z; Hoshida, Mara S; de Oliveira, Sérgio F; Bevilacqua, Estela

    2012-01-01

    PROBLEM In this study, we explored the relationship between decidual cells (DC) and interferon (IFN)-γ, in the presence or absence of ectoplacental cone (EC) using a coculture system. METHOD OF STUDY  Decidual cells and EC were isolated from pregnant mice on gestation day 7.5. DCs were cultured for 48 hr and then treated with fresh EC. After characterization, they were treated with IFN-γ, and cell death was evaluated. RESULTS  Interferon-γ drastically increased decidual apoptosis, which was partially reverted by the addition of EC to the IFN-γ-treated decidual culture. Moreover, the addition of EC to non-treated DC cultures was also capable of attenuating death rates. CONCLUSION Resistance to apoptosis may be induced in DC by the EC. This suggests that EC may participate in the inhibition of IFN-γ-dependent apoptosis and, therefore, play important role for DC survival in a cytokine-enriched placental environment. PMID:21883617

  3. Effects of IRF1 and IFN-β interaction on the M1 polarization of macrophages and its antitumor function

    PubMed Central

    XIE, CHANGLI; LIU, CUIYING; WU, BITAO; LIN, YAN; MA, TINGTING; XIONG, HAIYU; WANG, QIN; LI, ZIWEI; MA, CHENYU; TU, ZHIGUANG

    2016-01-01

    Macrophages that differentiate from precursor monocytes can be polarized into a classically activated (M1) or alternatively activated (M2) status depending on different stimuli. Generally, interferon (IFN)-γ and lipopolysaccharide (LPS) are considered the classical stimuli with which to establish M1 polarization. IFN regulatory factor (IRF)1 and IFN-β are two crucial molecules involved in IFN-γ- and LPS-initialed signaling. However, the association between IRF1 and IFN-β in the context of the M1 polarization of macrophages is not yet fully understood. In this study, we demonstrate that U937-derived macrophages, in response to IFN-γ and LPS stimulation, readily acquire an M1 status, indicated by the increased expression of interleukin (IL)-12, IL-6, IL-23, tumor necrosis factor (TNF)-α and the M1-specific cell surface antigen, CD86, and the decreased expression of the M2-specific mannose receptor, CD206. However, the knockdown of IRF1 in U937-derived macrophages led to an impaired M1 status, as indicated by the decreased expression of the above-mentioned M1 markers, and the increased expression of the M2 markers, CD206 and IL-10. A similar phenomenon was observed in the M1 macrophages in which IFN-β was inhibited. Furthermore, we demonstrated that IRF1 and IFN-β may interact with each other in the IFN-γ- and LPS-initiated signaling pathway, and contribute to the IRF5 regulation of M1 macrophages. In addition, the conditioned medium collected from the M1 macrophages in which IRF1 or IFN-β were inhibited, exerted pro-tumor effects on the HepG2 and SMMC-7721 cells, as indicated by an increase in proliferation, the inhibition of apoptosis and an enhanced invasion capability. The findings of our study suggest that the interactions of IRF1, IFN-β and IRF5 are involved in the M1 polarization of macro phages and have antitumor functions. These data may provide a novel antitumor strategy for targeted cancer therapy. PMID:27176664

  4. Role of IFN-γ and LPS on neuron/glial co-cultures infected by Neospora caninum

    PubMed Central

    De Jesus, Erica Etelvina Viana; Santos, Alex Barbosa Dos; Ribeiro, Catia Suse Oliveira; Pinheiro, Alexandre Moraes; Freire, Songeli Menezes; El-Bachá, Ramon Santos; Costa, Silvia Lima; de Fatima Dias Costa, Maria

    2014-01-01

    Neospora caninum causes cattle abortion and neurological symptoms in dogs. Although infection is usually asymptomatic, classical neurological symptoms of neosporosis may be associated with encephalitis. This parasite can grow in brain endothelial cells without markedly damages, but it can modulate the cellular environment to promote its survival in the brain. In previous studies, we described that IFN-γ decreased the parasite proliferation and down regulated nitric oxide (NO) production in astrocyte/microglia cultures. However, it remains unclear how glial cells respond to N. caninum in the presence of neurons. Therefore, we evaluated the effect of 300 IU/mL IFN-γ or 1.0 mg/mL of LPS on infected rat neuron/glial co-cultures. After 72 h of infection, LPS did not affect the mitochondrial dehydrogenase activity. However, IFN-γ decreased this parameter by 15.5 and 12.0% in uninfected and infected cells, respectively. The number of tachyzoites decreased 54.1 and 44.3% in cells stimulated with IFN-γ and LPS, respectively. Infection or LPS treatment did not change NO production. On the other hand, IFN-γ induced increased nitrite release in 55.7%, but the infection reverted this induction. IL-10 levels increased only in infected cultures (treated or not), meanwhile PGE2 release was improved in IFN-γ/infected or LPS/infected cells. Although IFN-γ significantly reduced the neurite length in uninfected cultures (42.64%; p < 0.001), this inflammatory cytokine reverted the impairment of neurite outgrowth induced by the infection (81.39%). The results suggest a neuroprotective potential response of glia to N. caninum infection under IFN-γ stimulus. This observation contributes to understand the immune mediated mechanisms of neosporosis in central nervous system (CNS). PMID:25386119

  5. Positive feedback regulation of type I IFN production by the IFN-inducible DNA sensor cGAS

    PubMed Central

    Ma, Feng; Li, Bing; Liu, Su-yang; Iyer, Shankar S; Yu, Yongxin; Wu, Aiping; Cheng, Genhong

    2014-01-01

    Rapid and robust induction of type I interferon (IFN-I) is a critical event in host antiviral innate immune response. It has been well demonstrated that cyclic GMP-AMP (cGAMP) synthase (cGAS) plays an important role in sensing cytosolic DNA and triggering stimulator of interferon genes (STING)-dependent signaling to induce IFN-I. However, it is largely unknown how cGAS itself is regulated during pathogen infection and IFN-I production. Here, we show that pattern-recognition receptor (PRR) ligands including lipidA, LPS, polyI:C, polydA:dT, and cGAMP induce cGAS expression in a IFN-I-dependent manner in both mouse and human macrophages. Further experiments indicate that cGAS is an IFN-stimulated gene (ISG), and two adjacent IFN-sensitive response elements (ISREs) in the promoter region of cGAS mediate the induction of cGAS by IFN-I. In addition, we show that optimal production of IFNβ triggered by polydA:dT or HSV-1 requires IFNAR signaling. Knockdown of the constitutively expressed DNA sensor DDX41 attenuates polydA:dT-triggered IFNβ production and cGAS induction. By analyzing the dynamic expression of polydA:dT-induced IFNβ and cGAS transcripts, we have found that induction of IFNβ is earlier than cGAS. Furthermore, we have provided evidence that induction of cGAS by IFN-I meditates the subsequent positive feedback regulation of DNA-triggered IFN-I production. Thus, our study not only provides a novel mechanism of modulating cGAS expression, but also adds another layer of regulation in DNA-triggered IFN-I production by induction of cGAS. PMID:25609843

  6. Impaired Antiviral Stress Granule and IFN-β Enhanceosome Formation Enhances Susceptibility to Influenza Infection in Chronic Obstructive Pulmonary Disease Epithelium.

    PubMed

    Hsu, Alan C-Y; Parsons, Kristy; Moheimani, Fatemeh; Knight, Darryl A; Hansbro, Philip M; Fujita, Takashi; Wark, Peter A

    2016-07-01

    Chronic obstructive pulmonary disease (COPD) is a serious lung disease that progressively worsens lung function. Those affected are highly susceptible to influenza virus infections that result in exacerbations with exaggerated symptoms with increased mortality. The mechanisms underpinning this increased susceptibility to infection in COPD are unclear. In this study, we show that primary bronchial epithelial cells (pBECs) from subjects with COPD have impaired induction of type I IFN (IFN-β) and lead to heightened viral replication after influenza viral infection. COPD pBECs have reduced protein levels of protein kinase (PK) R and decreased formation of PKR-mediated antiviral stress granules, which are critical in initiating type I IFN inductions. In addition, reduced protein expression of p300 resulted in decreased activation of IFN regulatory factor 3 and subsequent formation of IFN-β enhanceosome in COPD pBECs. The decreased p300 induction was the result of enhanced levels of microRNA (miR)-132. Ectopic expression of PKR or miR-132 antagomiR alone failed to restore IFN-β induction, whereas cotreatment increased antiviral stress granule formation, induction of p300, and IFN-β in COPD pBECs. This study reveals that decreased induction of both PKR and p300 proteins contribute to impaired induction of IFN-β in COPD pBECs upon influenza infection. PMID:26807508

  7. The Effect of Inhaled IFN-β on Worsening of Asthma Symptoms Caused by Viral Infections. A Randomized Trial

    PubMed Central

    Harrison, Tim; Johnston, Sebastian L.; Gabbay, Flic; Wark, Peter; Thomson, Neil C.; Niven, Robert; Singh, Dave; Reddel, Helen K.; Davies, Donna E.; Marsden, Richard; Boxall, Christine; Dudley, Sarah; Plagnol, Vincent; Holgate, Stephen T.; Monk, Phillip

    2014-01-01

    Rationale: Ex vivo, bronchial epithelial cells from people with asthma are more susceptible to rhinovirus infection caused by deficient induction of the antiviral protein, IFN-β. Exogenous IFN-β restores antiviral activity. Objectives: To compare the efficacy and safety of inhaled IFN-β with placebo administered to people with asthma after onset of cold symptoms to prevent or attenuate asthma symptoms caused by respiratory viruses. Methods: A total of 147 people with asthma on inhaled corticosteroids (British Thoracic Society Steps 2–5), with a history of virus-associated exacerbations, were randomized to 14-day treatment with inhaled IFN-β (n = 72) or placebo (n = 75) within 24 hours of developing cold symptoms and were assessed clinically, with relevant samples collected to assess virus infection and antiviral responses. Measurements and Main Results: A total of 91% of randomized patients developed a defined cold. In this modified intention-to-treat population, asthma symptoms did not get clinically significantly worse (mean change in six-item Asthma Control Questionnaire <0.5) and IFN-β treatment had no significant effect on this primary endpoint, although it enhanced morning peak expiratory flow recovery (P = 0.033), reduced the need for additional treatment, and boosted innate immunity as assessed by blood and sputum biomarkers. In an exploratory analysis of the subset of more difficult-to-treat, Step 4-5 people with asthma (n = 27 IFN-β; n = 31 placebo), Asthma Control Questionnaire-6 increased significantly on placebo; this was prevented by IFN-β (P = 0.004). Conclusions: Although the trial did not meet its primary endpoint, it suggests that inhaled IFN-β is a potential treatment for virus-induced deteriorations of asthma in difficult-to-treat people with asthma and supports the need for further, adequately powered, trials in this population. Clinical trial registered with www.clinicaltrials.gov (NCT 01126177). PMID:24937476

  8. Regulation of DTH and IgE responses by IL-4 and IFN-gamma in immunized mice given pertussis toxin.

    PubMed Central

    Mu, H H; Sewell, W A

    1994-01-01

    Interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) are cytokines with important functions in regulating immune responses. IFN-gamma may be produced by cells responsible for delayed-type hypersensitivity (DTH), whereas IL-4 is essential for IgE production. Pertussis toxin (PT) from Bordetella pertussis enhances both DTH and IgE responses, and causes enhancement of both IFN-gamma and IL-4 secretion in immunized mice. In the present study, the effects of neutralizing monoclonal antibodies against IFN-gamma or IL-4 on DTH, serum IgE and cytokine production were assessed. Treatment with a monoclonal anti-IL-4 antibody at the time of immunization caused a striking increase in DTH responses, and elicited enhanced IFN-gamma expression, while inhibition of the production of IL-4 and IgE was observed. By contrast, injection of a monoclonal anti-IFN-gamma antibody was followed by significant but not complete suppression of DTH reactions. IFN-gamma secretion was also inhibited, whereas IL-4 production and serum IgE were increased. Thus antibodies to IL-4 and IFN-gamma, given at the time of immunization, can profoundly influence the nature of short-term immune responses elicited by PT in immunized mice. Images Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:7875744

  9. Methylation of CIITA promoter IV causes loss of HLA-II inducibility by IFN-γ in promyelocytic cells

    PubMed Central

    De Ambrosis, Alessandro; Banelli, Barbara; Pira, Giuseppina Li; Aresu, Ottavia; Romani, Massimo; Ferrini, Silvano; Accolla, Roberto S.

    2008-01-01

    The human promyelocytic cell line THP-1 expresses high level of HLA class II (HLA-II) molecules after IFN-γ treatment. Here, we report a variant of THP-1 that does not express HLA-II after IFN-γ. The variant's HLA-II phenotype is constant over time in culture and it is not related to a defective IFN-γ-signalling pathway. Transfection of CIITA, the HLA-II transcriptional activator, under the control of a cytomegalovirus promoter rescues high level of HLA-DR surface expression in the variant indicating that the biosynthetic block resides in the expression of CIITA and not in the CIITA-dependent transactivation of the HLA-II promoters. Treatment of the variant with 5-azacytidine (5-aza), which inhibits CpG methylation, restores inducibility of HLA-II by IFN-γ both at transcriptional and phenotypic level and antigen presenting and processing function of the variant. DNA studies demonstrate that the molecular defect of the THP-1 variant originates from the methylation of the CIITA promoter IV. Furthermore, treatment with 5-aza produces a substantial demethylation of CIITA promoter IV and a significant increase of IFN-γ-dependent HLA-II expression in another myelomonocytic cell line, U937. Therefore hyper-methylation of CIITA promoter IV may be a relevant mechanism of epigenetic control preventing HLA-II IFN-γ inducibility in the myelomonocytic cell lineage. PMID:18829986

  10. Oxidative Stress Facilitates IFN-γ-Induced Mimic Extracellular Trap Cell Death in A549 Lung Epithelial Cancer Cells.

    PubMed

    Lin, Chiou-Feng; Chen, Chia-Ling; Chien, Shun-Yi; Tseng, Po-Chun; Wang, Yu-Chih; Tsai, Tsung-Ting

    2016-01-01

    We previously demonstrated that IFN-γ induces an autophagy-regulated mimic extracellular trap cell death (ETosis) in A549 human lung cancer cells. Regarding reactive oxygen species (ROS) are involved in ETosis, this study investigated the role of oxidative stress. After IFN-γ stimulation, a necrosis-like cell death mimic ETosis occurred accompanied by the inhibition of cell growth, aberrant nuclear staining, and nucleosome release. ROS were generated in a time-dependent manner with an increase in NADPH oxidase component protein expression. STAT1-mediated IFN regulatory factor-1 activation was essential for upregulating ROS production. By genetically silencing p47phox, IFN-γ-induced ROS and mimic ETosis were significantly attenuated. This mechanistic study indicated that ROS may mediate DNA damage followed by histone H3 citrullination. Furthermore, ROS promoted IFN-γ-induced mimic ETosis in cooperation with autophagy. These findings further demonstrate that ROS regulates IFN-γ-induced mimic ETosis in lung epithelial malignancy. PMID:27575372

  11. Enhanced antibacterial potential in UBP43-deficient mice against Salmonella typhimurium infection by up-regulating type I IFN signaling.

    PubMed

    Kim, Keun Il; Malakhova, Oxana A; Hoebe, Kasper; Yan, Ming; Beutler, Bruce; Zhang, Dong-Er

    2005-07-15

    ISG15 is an IFN-inducible ubiquitin-like protein and its expression and conjugation to target proteins are dramatically induced upon viral or bacterial infection. We have generated a UBP43 knockout mouse model that is lacking an ISG15-specific isopeptidase to study the biological role of the protein ISGylation system. We report that UBP43-deficient mice are hypersensitive to LPS-induced lethality and that TIR domain-containing adapter inducing IFN-beta --> IFN regulatory factor 3 --> type I IFN is the major axis to induce protein ISGylation and UBP43 expression in macrophages upon LPS treatment. In ubp43(-/-) macrophages, upon LPS treatment we detected increased expression of IFN-stimulated genes, including genes for several cytokines and chemokines involved in the innate immune response. The ubp43(-/-) mice were able to restrict the growth of Salmonella typhimurium more efficiently than wild-type mice. These results clearly demonstrate two aspects of IFN-signaling, a beneficial effect against pathogens but a detriment to the body without strict control. PMID:16002682

  12. Oxidative Stress Facilitates IFN-γ-Induced Mimic Extracellular Trap Cell Death in A549 Lung Epithelial Cancer Cells

    PubMed Central

    Lin, Chiou-Feng; Chen, Chia-Ling; Chien, Shun-Yi; Tseng, Po-Chun; Wang, Yu-Chih; Tsai, Tsung-Ting

    2016-01-01

    We previously demonstrated that IFN-γ induces an autophagy-regulated mimic extracellular trap cell death (ETosis) in A549 human lung cancer cells. Regarding reactive oxygen species (ROS) are involved in ETosis, this study investigated the role of oxidative stress. After IFN-γ stimulation, a necrosis-like cell death mimic ETosis occurred accompanied by the inhibition of cell growth, aberrant nuclear staining, and nucleosome release. ROS were generated in a time-dependent manner with an increase in NADPH oxidase component protein expression. STAT1-mediated IFN regulatory factor-1 activation was essential for upregulating ROS production. By genetically silencing p47phox, IFN-γ-induced ROS and mimic ETosis were significantly attenuated. This mechanistic study indicated that ROS may mediate DNA damage followed by histone H3 citrullination. Furthermore, ROS promoted IFN-γ-induced mimic ETosis in cooperation with autophagy. These findings further demonstrate that ROS regulates IFN-γ-induced mimic ETosis in lung epithelial malignancy. PMID:27575372

  13. Stat-mediated Signaling Induced by Type I and Type II Interferons (IFNs) Is Differentially Controlled through Lipid Microdomain Association and Clathrin-dependent Endocytosis of IFN Receptors

    PubMed Central

    Marchetti, Marta; Monier, Marie-Noelle; Fradagrada, Alexandre; Mitchell, Keith; Baychelier, Florence; Eid, Pierre; Johannes, Ludger

    2006-01-01

    Type I (α/β) and type II (γ) interferons (IFNs) bind to distinct receptors, although they activate the same signal transducer and activator of transcription, Stat1, raising the question of how signal specificity is maintained. Here, we have characterized the sorting of IFN receptors (IFN-Rs) at the plasma membrane and the role it plays in IFN-dependent signaling and biological activities. We show that both IFN-α and IFN-γ receptors are internalized by a classical clathrin- and dynamin-dependent endocytic pathway. Although inhibition of clathrin-dependent endocytosis blocked the uptake of IFN-α and IFN-γ receptors, this inhibition only affected IFN-α–induced Stat1 and Stat2 signaling. Furthermore, the antiviral and antiproliferative activities induced by IFN-α but not IFN-γ were also affected. Finally, we show that, unlike IFN-α receptors, activated IFN-γ receptors rapidly become enriched in plasma membrane lipid microdomains. We conclude that IFN-R compartmentalization at the plasma membrane, through clathrin-dependent endocytosis and lipid-based microdomains, plays a critical role in the signaling and biological responses induced by IFNs and contributes to establishing specificity within the Jak/Stat signaling pathway. PMID:16624862

  14. Type I IFN promotes NK cell expansion during viral infection by protecting NK cells against fratricide.

    PubMed

    Madera, Sharline; Rapp, Moritz; Firth, Matthew A; Beilke, Joshua N; Lanier, Lewis L; Sun, Joseph C

    2016-02-01

    Type I interferon (IFN) is crucial in host antiviral defense. Previous studies have described the pleiotropic role of type I IFNs on innate and adaptive immune cells during viral infection. Here, we demonstrate that natural killer (NK) cells from mice lacking the type I IFN-α receptor (Ifnar(-/-)) or STAT1 (which signals downstream of IFNAR) are defective in expansion and memory cell formation after mouse cytomegalovirus (MCMV) infection. Despite comparable proliferation, Ifnar(-/-) NK cells showed diminished protection against MCMV infection and exhibited more apoptosis compared with wild-type NK cells. Furthermore, we show that Ifnar(-/-) NK cells express increased levels of NK group 2 member D (NKG2D) ligands during viral infection and are susceptible to NK cell-mediated fratricide in a perforin- and NKG2D-dependent manner. Adoptive transfer of Ifnar(-/-) NK cells into NK cell-deficient mice reverses the defect in survival and expansion. Our study reveals a novel type I IFN-dependent mechanism by which NK cells evade mechanisms of cell death after viral infection. PMID:26755706

  15. IFN-γ Primes Keratinocytes for HSV-1-Induced Inflammasome Activation.

    PubMed

    Strittmatter, Gerhard E; Sand, Jennifer; Sauter, Marlies; Seyffert, Michael; Steigerwald, Robin; Fraefel, Cornel; Smola, Sigrun; French, Lars E; Beer, Hans-Dietmar

    2016-03-01

    Inflammasomes are immune complexes that induce an inflammatory response upon sensing of different stress signals. This effect is mainly mediated by activation and secretion of the proinflammatory cytokines proIL-1β and -18. Here we report that infection of human primary keratinocytes with the double-stranded DNA viruses modified vaccinia virus Ankara (MVA) or herpes simplex virus type 1 (HSV-1)-induced secretion of mature IL-1β and -18. This secretion was dependent on several inflammasome complexes; however, the absent in melanoma 2 (AIM2) inflammasome, which is activated by binding of double-stranded DNA, played the most important role. Whereas prestimulation of keratinocytes with IFN-γ moderately increased MVA-induced IL-1β and IL-18 secretion, it was essential for substantial secretion of these cytokines in response to herpes simplex virus type 1 infection. IFN-γ partially restored HSV-1 suppressed proIL-1β expression and was also required for inflammasome activation. Most importantly, IFN-γ strongly suppressed virus replication in keratinocytes in vitro and ex vivo, which was independent of inflammasome activation. Our results suggest that, similar to Herpesviridae infection in mice, HSV-1 replication in human skin is controlled by a positive feedback loop of keratinocyte-derived IL-1/IL-18 and IFN-γ expressed by immune cells. PMID:26739094

  16. CRAM-A indicates IFN-γ-associated inflammatory response in breast cancer.

    PubMed

    Sarmadi, Parisa; Tunali, Gurcan; Esendagli-Yilmaz, Guldal; Yilmaz, Kerim Bora; Esendagli, Gunes

    2015-12-01

    Atypical chemokine receptors (ACKRs) function as endpoint regulators of chemokine gradients. These non-signaling receptors that are transiently expressed under inflammatory conditions have critical roles in the control or maintenance of immune responses. Alternatively, here, CCRL2 (ACKR5) expression was determined to be constitutive in breast cancer cells. Increased amount of CCRL2 was also found in breast tumor tissues with high immune infiltration. Its expression was upregulated in the presence of pro-inflammatory cytokines, IL-1β, TNF-α, IL-6, and especially IFN-γ⋅ Moreover, an alternative transcript of CCRL2 gene, CRAM-A, was specifically expressed in a transient fashion under the influence of IFN-γ. CRAM-A expression was also positively correlated with the presence of IFN-γ mRNA in patient samples. CCRL2-associated chemotactic molecules, chemerin, CCL19 and CCL5, were also detected in cancer tissues and CCL5 mRNA level was correlated with that of CRAM-A and IFN-γ. Hence, in breast cancer, CRAM-A becomes specifically upregulated under inflammatory stimuli and may serve as a potential marker of immune response. PMID:26563945

  17. Activation-specific metabolic requirements for NK cell IFN-γ production1

    PubMed Central

    Keppel, Molly P.; Topcagic, Nermina; Mah, Annelise Y.; Vogel, Tiphanie P.; Cooper, Megan A.

    2014-01-01

    There has been increasing recognition of the importance of cellular metabolism and metabolic substrates for the function and differentiation of immune cells. Here, for the first time, we investigate the metabolic requirements for production of IFN-γ by freshly isolated NK cells. Primary murine NK cells mainly utilize mitochondrial oxidative phosphorylation at rest and with short-term activation. Remarkably, we discovered significant differences in the metabolic requirements of murine NK cell IFN-γ production depending upon the activation signal. Stimulation of NK cell IFN-γ production was independent of glycolysis or mitochondrial oxidative phosphorylation when cells were activated with IL-12+IL-18. By contrast, stimulation via activating NK receptors required glucose-driven oxidative phosphorylation. Prolonged treatment with high-dose, but not low dose, IL-15 eliminated the metabolic requirement for receptor stimulation. In summary, this study demonstrates that metabolism provides an essential second signal for induction of IFN-γ production by activating NK cell receptors that can be reversed with prolonged high-dose IL-15 treatment. PMID:25595780

  18. IFN-γ induction by neutrophil-derived IL-17A homodimer augments pulmonary antibacterial defense.

    PubMed

    Cai, S; Batra, S; Langohr, I; Iwakura, Y; Jeyaseelan, S

    2016-05-01

    The role of interleukin-17A (IL-17A) in host defense against Legionella pneumophila remains elusive. To address this issue, we used Il17a(-/-), Il17f(-/-), and Il17a/Il17f(-/-) mice on a C57Bl/6 (non-permissive) background and IL-17 neutralizing Abs in mice on an A/J (permissive) background. Higher bacterial (L. pneumophila) counts in the lung and blood along with reduced neutrophil recruitment were detected in Il17a(-/-), but not Il17f(-/-), mice. We found that neutrophils produce IL-17A homodimer (IL-17A) during L. pneumophila infection, and hematopoietic cell-derived IL-17A is known to be important for bacterial clearance. Thus, intratracheal administration of wild-type neutrophils or recombinant IL-17A restored bacterial clearance and neutrophil recruitment in Il17a(-/-) mice. Furthermore, neutrophil-depleted Rag2(-/-) and Rag2/Il-2rγ(-/-) mice exhibited increased bacterial burden, reduced neutrophil influx and IL-17A production in the lung. Recombinant IFN-γ administration in Il17a(-/-) mice augmented bacterial elimination, whereas IL-17A administration in Ifnγ(-/-) mice did not augment bacterial clearance. IFN-γ is produced by T cells, but not neutrophils or macrophages, suggesting that neutrophil-derived IL-17A induces IFN-γ in a paracrine fashion. Human pneumonic lungs and human neutrophils challenged with L. pneumophila exhibited increased numbers of IL-17A producing cells. These findings display a novel function of neutrophil-derived IL-17A in antibacterial defense via the induction of IFN-γ in a paracrine manner. PMID:26349661

  19. Hemagglutinin of Influenza A Virus Antagonizes Type I Interferon (IFN) Responses by Inducing Degradation of Type I IFN Receptor 1

    PubMed Central

    Xia, Chuan; Vijayan, Madhuvanthi; Pritzl, Curtis J.; Fuchs, Serge Y.; McDermott, Adrian B.

    2015-01-01

    ABSTRACT Influenza A virus (IAV) employs diverse strategies to circumvent type I interferon (IFN) responses, particularly by inhibiting the synthesis of type I IFNs. However, it is poorly understood if and how IAV regulates the type I IFN receptor (IFNAR)-mediated signaling mode. In this study, we demonstrate that IAV induces the degradation of IFNAR subunit 1 (IFNAR1) to attenuate the type I IFN-induced antiviral signaling pathway. Following infection, the level of IFNAR1 protein, but not mRNA, decreased. Indeed, IFNAR1 was phosphorylated and ubiquitinated by IAV infection, which resulted in IFNAR1 elimination. The transiently overexpressed IFNAR1 displayed antiviral activity by inhibiting virus replication. Importantly, the hemagglutinin (HA) protein of IAV was proved to trigger the ubiquitination of IFNAR1, diminishing the levels of IFNAR1. Further, influenza A viral HA1 subunit, but not HA2 subunit, downregulated IFNAR1. However, viral HA-mediated degradation of IFNAR1 was not caused by the endoplasmic reticulum (ER) stress response. IAV HA robustly reduced cellular sensitivity to type I IFNs, suppressing the activation of STAT1/STAT2 and induction of IFN-stimulated antiviral proteins. Taken together, our findings suggest that IAV HA causes IFNAR1 degradation, which in turn helps the virus escape the powerful innate immune system. Thus, the research elucidated an influenza viral mechanism for eluding the IFNAR signaling pathway, which could provide new insights into the interplay between influenza virus and host innate immunity. IMPORTANCE Influenza A virus (IAV) infection causes significant morbidity and mortality worldwide and remains a major health concern. When triggered by influenza viral infection, host cells produce type I interferon (IFN) to block viral replication. Although IAV was shown to have diverse strategies to evade this powerful, IFN-mediated antiviral response, it is not well-defined if IAV manipulates the IFN receptor-mediated signaling

  20. Expression of the MHC Class II Transactivator (CIITA) type IV promoter in B lymphocytes and regulation by IFN

    PubMed Central

    Piskurich, Janet F.; Gilbert, Carolyn A.; Ashley, Brittany D.; Zhao, Mojun; Chen, Han; Wu, Jian; Wright, Kenneth L.

    2006-01-01

    The MHC class II transactivator (CIITA), the master regulator of MHC class II (MHC II) expression, is a co-activator that controls MHC II transcription. Human B lymphocytes express MHC II constitutively due to persistent activity of CIITA promoter III (pIII), one of the four potential promoters (pI-pIV) of this gene. Although increases in MHC II expression in B cells in response to cytokines have been observed and induction of MHC II and CIITA by IFN-γ has been studied in a number of different cell types, the specific effects of IFN-γ on CIITA expression in B cells have not been studied. To investigate the regulation of CIITA expression by IFN-γ in B cells, RT-PCR, in vivo and in vitro protein/DNA binding studies, and functional promoter analyses were performed. Both MHC II and CIITA type IV-specific RNAs increased in human B lymphocytes in response to IFN-γ treatment. CIITA promoter analysis confirmed that pIV is IFN-γ inducible in B cells and that the GAS and IRF-E sites are necessary for full induction. DNA binding of IRF-1 and IRF-2, members of the IFN regulatory factor family, was up-regulated in B cells in response to IFN-γ and increased the activity of CIITA pIV. In vivo genomic footprint analysis demonstrated proteins binding at the GAS, IRF-E and E box sites of CIITA pIV. Although CIITA pIII is considered to be the hematopoietic-specific promoter of CIITA, these findings demonstrate that pIV is active in B lymphocytes and potentially contributes to the expression of CIITA and MHC II in these cells. PMID:15950283

  1. Chicken STING Mediates Activation of the IFN Gene Independently of the RIG-I Gene.

    PubMed

    Cheng, Yuqiang; Sun, Yingjie; Wang, Hengan; Yan, Yaxian; Ding, Chan; Sun, Jianhe

    2015-10-15

    Stimulator of IFN genes (STING) is an adaptor that functions downstream of retinoic acid-inducible gene I (RIG-I) in mammalian cells; however, RIG-I is absent in chickens. We identified chicken STING (chSTING) as a critical mediator of virus-triggered type I IFN signaling in RIG-I-null chicken cells. Overexpression of chSTING in DF-1 cells inhibited Newcastle disease virus and avian influenza virus (AIV) viral replication and activated IRF-7 and NF-κB to induce expression of type I IFNs. Knockdown of endogenous chSTING abolished virus-triggered activation of IRF-7 and IFN-β and increased viral yield. chSTING was a critical component in the virus-triggered IRF-7 activation pathway and the cellular antiviral response. chSTING predominantly localized to the outer membrane of the endoplasmic reticulum and was also found in the mitochondrial membrane. Furthermore, knockdown of chSTING blocked polyinosinic-polycytidylic acid-, poly(deoxyadenylic-deoxythymidylic) acid-, and melanoma differentiation-associated gene 5 (MDA5)-stimulated induction of IFN-β. Coimmunoprecipitation experiments indicated that chicken MDA5 could interact with chSTING, and this interaction was enhanced by ectopically expressed chicken mitochondrial antiviral-signaling protein. Together, these results indicated that chSTING is an important regulator of chicken innate immune signaling and might be involved in the MDA5 signaling pathway in chicken cells. These results help with understanding the biological role of STING in innate immunity during evolution. PMID:26392466

  2. IFN-γ differentially modulates memory-related processes under basal and chronic stressor conditions

    PubMed Central

    Litteljohn, Darcy; Nelson, Eric; Hayley, Shawn

    2014-01-01

    Cytokines are inflammatory messengers that orchestrate the brain’s response to immunological challenges, as well as possibly even toxic and psychological insults. We previously reported that genetic ablation of the pro-inflammatory cytokine, interferon-gamma (IFN-γ), attenuated some of the corticosteroid, cytokine, and limbic dopaminergic variations induced by 6 weeks of exposure to an unpredictable psychologically relevant stressor. Presently, we sought to determine whether a lack of IFN-γ would likewise modify the impact of chronic stress on hippocampus-dependent memory function and related neurotransmitter and neurotrophin signaling systems. As predicted, chronic stress impaired spatial recognition memory (Y-maze task) in the wild-type animals. In contrast, though the IFN-γ knockouts (KOs) showed memory disturbances in the basal state, under conditions of chronic stress these mice actually exhibited facilitated memory performance. Paralleling these findings, while overall the KOs displayed altered noradrenergic and/or serotonergic activity in the hippocampus and locus coeruleus, norepinephrine utilization in both of these memory-related brain regions was selectively increased among the chronically stressed KOs. However, contrary to our expectations, neither IFN-γ deletion nor chronic stressor exposure significantly affected nucleus accumbens dopaminergic neurotransmission or hippocampal brain-derived neurotrophic factor protein expression. These findings add to a growing body of evidence implicating cytokines in the often differential regulation of neurobehavioral processes in health and disease. Whereas in the basal state IFN-γ appears to be involved in sustaining memory function and the activity of related brain monoamine systems, in the face of ongoing psychologically relevant stress the cytokine may, in fact, act to restrict potentially adaptive central noradrenergic and spatial memory responses. PMID:25477784

  3. Nonerosive arthritis in lupus is mediated by IFN-α stimulated monocyte differentiation that is nonpermissive of osteoclastogenesis

    PubMed Central

    Mensah, Kofi A.; Mathian, Alexis; Ma, Lin; Xing, Lianping; Ritchlin, Christopher T.; Schwarz, Edward M.

    2010-01-01

    Objective In contrast to rheumatoid arthritis (RA), Jaccoud arthritis (JA) joint inflammation in systemic lupus erythematosus (SLE) is nonerosive. Although the mechanism responsible is unknown, the anti-osteoclastogenic cytokine interferon-alpha (IFN-α), whose transcriptome is present in SLE monocytes, may be responsible. To test this, we examined effects of IFN-α versus lupus disease on osteoclasts and erosion in the NZBxNZW F1 SLE mouse model with K/BxN serum-induced arthritis (SIA). Methods Elevated systemic IFN-α levels were obtained by administration of an adenoviral vector expressing IFN-α (Ad-IFN-α). SLE disease was marked by anti-dsDNA antibody titer and proteinuria, and Ifi202 and Mx1 expression represented the IFN-α transcriptome. Micro-CT was used to evaluate bone erosions. Flow cytometry for CD11b and CD11c was used to evaluate the frequency of circulating osteoclast precursors (OCP) and myeloid dendritic cells (mDC) in blood. Results Administration of Ad-IFN-α to NZBxNZW F1 mice induced osteopetrosis. Pre-autoimmune NZBxNZW F1 mice are fully susceptible to focal erosions in the setting of SIA. However, NZBxNZW F1 mice with high anti-dsDNA antibody titers and the IFN-α transcriptome were protected against bone erosions. Ad-IFN-α pre-treatment of NZW mice before K/BxN serum administration also resulted in protection against bone erosion (r2=0.4720, p<0.01), which was associated with a decrease in circulating CD11b+CD11c− OCP, and a concomitant increase in CD11b+CD11c+ cells (r2=0.6330, p<0.05) that are phenotypic of mDC. Conclusion These findings suggest that IFN-α in SLE shifts monocyte development toward mDC at the expense of osteoclastogenesis thereby resulting in decreased bone erosion. PMID:20131244

  4. Type I IFN Signaling Is Dispensable during Secondary Viral Infection.

    PubMed

    Hosking, Martin P; Flynn, Claudia T; Whitton, J Lindsay

    2016-08-01

    Innate immune responses in general, and type I interferons (T1IFNs) in particular, play an important and often essential role during primary viral infections, by directly combatting the virus and by maximizing the primary adaptive immune response. Several studies have suggested that T1IFNs also contribute very substantially to the secondary (recall) response; they are thought (i) to be required to drive the early attrition of memory T cells, (ii) to support the subsequent expansion of surviving virus-specific memory cells, and (iii) to assist in the suppression and clearance of the infectious agent. However, many of these observations were predicated upon models in which T1IFN signaling was interrupted prior to a primary immune response, raising the possibility that the resulting memory cells might be intrinsically abnormal. We have directly addressed this by using an inducible-Cre model system in which the host remains genetically-intact during the primary response to infection, and in which T1IFN signaling can be effectively ablated prior to secondary viral challenge. We report that, in stark contrast to primary infection, T1IFN signaling is not required during the recall response. IFNαβR-deficient memory CD8+ and CD4+ memory T cells undergo attrition and expansion with kinetics that are indistinguishable from those of receptor-sufficient cells. Moreover, even in the absence of functional T1IFN signaling, the host's immune capacity to rapidly suppress, and then to eradicate, a secondary infection remains intact. Thus, this study shows that T1IFN signaling is dispensable during the recall response to a virus infection. Moreover, two broader implications may be drawn. First, a T cell's requirement for a cytokine is highly dependent on the cell's maturation / differentiation status. Consequently, second, these data underscore the importance of evaluating a gene's impact by modulating its expression or function in a temporally-controllable manner. PMID:27580079

  5. Mechanism of IFN-γ in regulating OPN/Th17 pathway during vascular collagen remodeling of hypertension induced by ANG II

    PubMed Central

    Jiang, Lei; He, Pengcheng; Liu, Yong; Chen, Jiyan; Wei, Xuebiao; Tan, Ning

    2015-01-01

    More and more researches show that hypertensive vascular remodeling is closely related to the imbalance of immune system in recent years. IFN-γ is natural protein with the function of immune regulation and has resistance effect on vascular remodeling. However, the mechanism of IFN-γ is to be defined. This paper is to explore the mechanism of IFN-γ in regulating OPN/Th17 pathway. In this research, animal models of vascular collagen remodeling were established by inducing hypertensive mice with ANG II. There was no statistical significance when the systolic blood pressures and the percentages of wall thickness/lumen diameter in both groups of WT + AngII + IFN-γ and WT + PBS were compared (P=0.219>0.05, P=0.118>0.05). The concentration of serum precollagen-type I and III and their ratio in WT + AngII + IFN-γ group were decreased after the IFN-γ being given (P<0.01). Expression of OPN within tissue in WT + Ang II group was relatively high, but lowered after treated by IFN-γ. Th17 cell ratio was decreased in WT + AngII + IFN-γ group (P<0.01). Expressions of RORα and RORγt mRNA within Th17 cell were decreased (P<0.01). The content of IL-23 in WT + AngII + IFN-γ group was increased, while IL-10 and TGF-β decreased. It has proved that IFN-γ can regulate the hypertensive vascular collagen remodeling induced by ANG II, lower the systolic pressure and reduce the pathological damage of vascular collagen remodeling and the collagen synthesis. The mechanism may that the differentiation of Th17 is inhibited by suppressing the OPN expression and regulating the secretion of inflammatory cytokines. PMID:26823760

  6. A Rhesus Rhadinovirus Viral Interferon (IFN) Regulatory Factor Is Virion Associated and Inhibits the Early IFN Antiviral Response

    PubMed Central

    Morin, Gabriela; Robinson, Bridget A.; Rogers, Kelsey S.

    2015-01-01

    ABSTRACT The interferon (IFN) response is the earliest host immune response dedicated to combating viral infection. As such, viruses have evolved strategies to subvert this potent antiviral response. Two closely related gammaherpesviruses, Kaposi's sarcoma-associated herpesvirus (KSHV) and rhesus macaque rhadinovirus (RRV), are unique in that they express viral homologues to cellular interferon regulatory factors (IRFs), termed viral IRFs (vIRFs). Cellular IRFs are a family of transcription factors that are particularly important for the transcription of type I IFNs. Here, we demonstrate a strategy employed by RRV to ensure rapid inhibition of virus-induced type I IFN induction. We found that RRV vIRF R6, when expressed ectopically, interacts with a transcriptional coactivator, CREB-binding protein (CBP), in the nucleus. As a result, phosphorylated IRF3, an important transcriptional regulator in beta interferon (IFN-β) transcription, fails to effectively bind to the IFN-β promoter, thus inhibiting the activation of IFN-β genes. In addition, we found R6 within RRV virion particles via immunoelectron microscopy and, furthermore, that virion-associated R6 is capable of inhibiting the type I IFN response by preventing efficient binding of IRF3/CBP complexes to the IFN-β promoter in the context of infection. The work shown here is the first example of a vIRF being associated with either the KSHV or RRV virion. The presence of this immunomodulatory protein in the RRV virion provides the virus with an immediate mechanism to evade the host IFN response, thus enabling the virus to effectively establish an infection within the host. IMPORTANCE Kaposi's sarcoma-associated herpesvirus (KSHV) and the closely related rhesus macaque rhadinovirus (RRV) are the only viruses known to encode viral homologues to cellular interferon regulatory factors (IRFs), known as vIRFs. In KSHV, these proteins have been shown to play major roles in a variety of cellular processes and are

  7. IL-33 promotes innate IFN-γ production and modulates dendritic cell response in LCMV-induced hepatitis in mice.

    PubMed

    Liang, Yuejin; Jie, Zuliang; Hou, Lifei; Yi, Panpan; Wang, Wei; Kwota, Zakari; Salvato, Maria; de Waal Malefyt, Rene; Soong, Lynn; Sun, Jiaren

    2015-11-01

    Recent studies have revealed IL-33 as a key factor in promoting antiviral T-cell responses. However, it is less clear as to how IL-33 regulates innate immunity. In this study, we infected wild-type (WT) and IL-33(-/-) mice with lymphocytic choriomeningitis virus and demonstrated an essential role of infection-induced IL-33 expression for robust innate IFN-γ production in the liver. We first show that IL-33 deficiency resulted in a marked reduction in the number of IFN-γ(+) γδ T and NK cells, but an increase in that of IL-17(+) γδ T cells at 16 h postinfection. Recombinant IL-33 (rIL-33) treatment could reverse such deficiency via increasing IFN-γ-producing γδ T and NK cells, and inhibiting IL-17(+) γδ T cells. We also found that rIL-33-induced type 2 innate lymphoid cells were not involved in T-cell responses and liver injury, since the adoptive transfer of type 2 innate lymphoid cells neither affected the IFN-γ and TNF-α production in T cells, nor liver transferase levels in lymphocytic choriomeningitis virus infected mice. Interestingly, we found that while IL-33 was not required for costimulatory molecule expression, it was critical for DC proliferation and cytokine production. Together, this study highlights an essential role of IL-33 in regulating innate IFN-γ-production and DC function during viral hepatitis. PMID:26249267

  8. MiR-221 accentuates IFN׳s anti-HCV effect by downregulating SOCS1 and SOCS3.

    PubMed

    Xu, Gang; Yang, Fang; Ding, Cui-Ling; Wang, Jing; Zhao, Ping; Wang, Wen; Ren, Hao

    2014-08-01

    MiR-221 was reported to be upregulated and play roles in tumorigenesis of hepatitis C virus (HCV) associated hepatocellular carcinoma (HCC). However, the role of miR-221 in HCV infection remains unknown. In this study, it was found that miR-221 was upregulated in serum of HCV chronic hepatitis patients and Huh7.5.1 cells infected with HCVcc. Further studies indicated that miR-221 mimic could accentuate anti-HCV effect of IFN-α in HCVcc model, miR-221 mimic could further repressed 10% HCV RNA expression and 35-42% HCV core or NS5A protein expression in HCVcc infected Huh7.5.1 cells treated with 100IU/mL IFN-α, and miR-221 inhibitor resulted in the reverse effects. Furthermore, two members of suppressor of cytokine signaling (SOCS) family, SOCS1 and SOCS3, which are well established inhibitory factors on IFN/JAK/STAT pathway, were identified as the targets of miR-221 and were involved in the effect of miR-221. In conclusion, miR-221 could accentuate IFN׳s anti-HCV effect by targeting SOCS1 and SOCS3. PMID:25019494

  9. Plasmacytoid Dendritic Cell Activation and IFN-α Production Are Prominent Features of Murine Autoimmune Pancreatitis and Human IgG4-Related Autoimmune Pancreatitis.

    PubMed

    Arai, Yasuyuki; Yamashita, Kouhei; Kuriyama, Katsutoshi; Shiokawa, Masahiro; Kodama, Yuzo; Sakurai, Toshiharu; Mizugishi, Kiyomi; Uchida, Kazushige; Kadowaki, Norimitsu; Takaori-Kondo, Akifumi; Kudo, Masatoshi; Okazaki, Kazuichi; Strober, Warren; Chiba, Tsutomu; Watanabe, Tomohiro

    2015-10-01

    The abnormal immune response accompanying IgG4-related autoimmune pancreatitis (AIP) is presently unclear. In this study, we examined the role of plasmacytoid dendritic cell (pDC) activation and IFN-α production in this disease as well as in a murine model of AIP (MRL/Mp mice treated with polyinosinic-polycytidylic acid). We found that the development of AIP in treated MRL/Mp mice occurred in parallel with pancreatic accumulation of pDCs producing IFN-α, and with pDC depletion and IFN-α-blocking studies, we showed that such accumulation was necessary for AIP induction. In addition, we found that the pancreas of treated MRL/Mp mice contained neutrophil extracellular traps (NETs) shown previously to stimulate pDCs to produce IFN-α. Consistent with these findings, we found that patients with IgG4-related AIP also exhibited pancreatic tissue localization of IFN-α-expressing pDCs and had significantly higher serum IFN-α levels than healthy controls. In addition, the inflamed pancreas of these patients but not controls also contained NETs that were shown to be capable of pDC activation. More importantly, patient pDCs cultured in the presence of NETs produced greatly increased levels of IFN-α and induced control B cells to produce IgG4 (but not IgG1) as compared with control pDCs. These data suggest that pDC activation and production of IFN-α is a major cause of murine AIP; in addition, the increased pDC production of IFN-α and its relation to IgG4 production observed in IgG4-related AIP suggest that this mechanism also plays a role in the human disease. PMID:26297761

  10. NK Cell Activation in the Antitumor Response Induced by IFN-α Dendritic Cells Loaded with Apoptotic Cells from Follicular Lymphoma Patients.

    PubMed

    Lapenta, Caterina; Donati, Simona; Spadaro, Francesca; Castaldo, Paolo; Belardelli, Filippo; Cox, Maria C; Santini, Stefano M

    2016-08-01

    Follicular lymphoma (FL) is the most common form of indolent non-Hodgkin lymphoma. This malignancy is considered virtually incurable, with high response rates to therapy but frequent relapses. We investigated the ability of monocyte-derived dendritic cells generated in the presence of IFN-α and GM-CSF (IFN-DC) and loaded with apoptotic lymphoma cells to activate immune responses against FL cells, with the ultimate goal of designing novel patient-specific vaccination strategies for the treatment of FL. In this article, we show that apoptotic tumor cell-loaded IFN-DC from FL patients, which were cultured for 2 wk with autologous lymphocytes, led to Th1 response skewing, based on significantly higher levels of IFN-γ production and a remarkable increase in CD8(+) and NK cell frequency, consistent with the detection of enhanced cytotoxic effector function toward autologous FL cells. IFN-DC were found to promote efficient NK cell activation, increased expression of cytotoxicity receptors, and extensive IFN-γ production in the virtual absence of IL-10. Moreover, direct recognition and killing of primary autologous lymphoma cells by activated NK cells from FL patients was also demonstrated. A critical role was demonstrated for MHC class I-related chain A and B and membrane-bound IL-15 in IFN-DC-mediated NK cell activation and early IFN-γ production. The overall results indicate that IFN-DC loaded with autologous apoptotic FL cells represent a valuable tool for improving the potency of therapeutic cancer vaccines through the efficient induction of NK cell activation and promotion of CD8(+) T cell antitumor immunity. PMID:27357153

  11. Activation of IFN-γ/STAT/IRF-1 in Hepatic Responses to Klebsiella pneumoniae Infection

    PubMed Central

    Lin, Yi-Chun; Lu, Min-Chi; Lin, Chingju; Chiang, Ming-Ko; Jan, Ming-Shiou; Tang, Hui-Ling; Liu, Hsu-Chung; Lin, Wea-Lung; Huang, Chih-Yang; Chen, Chuan-Mu; Lai, Yi-Chyi

    2013-01-01

    Background Klebsiella pneumoniae-caused liver abscess (KLA) has become a health problem in Taiwan and is continually reported in other countries. Diabetes mellitus, the most common metabolic disorder, underlies half of the KLA patients in Taiwan. The clinical impact of KLA has been well-documented. Nevertheless, the molecular basis regarding how K. pneumoniae causes liver infection, particularly in diabetic individuals, remains unclear. Methodology/Principle Findings Auto-bioluminescence-expressing K. pneumoniae was inoculated into diabetic mice and age-match naïve control. With the use of in vivo imaging system, translocation of the bioluminescence-expressing K. pneumoniae from intestine to extraintestinal organs, mainly the liver, was noted in 80% of the diabetic mice, whereas the same bacteria causes extraintestinal infections in only 31% of naïve mice. Besides increased morbidity, the severity of hepatic tissue injury was also enhanced in the K. pneumoniae-infected diabetic mice. Upon K. pneumoniae infection, IFN-γ production was significantly evoked in the liver. To mediate IFN-γ signal, STAT (signal transducers and activators of transcription) 1 and 3 were activated in hepatocytes, and so was the expression of IRF (interferon regulatory factor)-1. Moreover, accumulation of neutrophils which was triggered by prolonged production of IL-1β and MIP-2, and significant increases in the level of active caspase 3 and phospho-eIF2α, were exclusively revealed in the K. pneumoniae-infected diabetic mice. Conclusion The activation of IFN-γ/STAT/IRF-1 signaling demonstrated by this work emphasizes the role of IFN-γ for mediating the hepatic response to K. pneumoniae infection. PMID:24223208

  12. ORF7-encoded accessory protein 7a of feline infectious peritonitis virus as a counteragent against IFN-α-induced antiviral response.

    PubMed

    Dedeurwaerder, Annelike; Olyslaegers, Dominique A J; Desmarets, Lowiese M B; Roukaerts, Inge D M; Theuns, Sebastiaan; Nauwynck, Hans J

    2014-02-01

    The type I IFN-mediated immune response is the first line of antiviral defence. Coronaviruses, like many other viruses, have evolved mechanisms to evade this innate response, ensuring their survival. Several coronavirus accessory genes play a central role in these pathways, but for feline coronaviruses this has never to our knowledge been studied. As it has been demonstrated previously that ORF7 is essential for efficient replication in vitro and virulence in vivo of feline infectious peritonitis virus (FIPV), the role of this ORF in the evasion of the IFN-α antiviral response was investigated. Deletion of ORF7 from FIPV strain 79-1146 (FIPV-Δ7) rendered the virus more susceptible to IFN-α treatment. Given that ORF7 encodes two proteins, 7a and 7b, it was further explored which of these proteins is active in this mechanism. Providing 7a protein in trans rescued the mutant FIPV-Δ7 from IFN sensitivity, which was not achieved by addition of 7b protein. Nevertheless, addition of protein 7a to FIPV-Δ3Δ7, a FIPV mutant deleted in both ORF3 and ORF7, could no longer increase the replication capacity of this mutant in the presence of IFN. These results indicate that FIPV 7a protein is a type I IFN antagonist and protects the virus from the antiviral state induced by IFN, but it needs the presence of ORF3-encoded proteins to exert its antagonistic function. PMID:24189622

  13. IFN-γ is essential for the inhibition of B16BL6 melanoma lung metastasis in chronic alcohol drinking mice.

    PubMed

    Zhang, Hui; Zhu, Zhaohui; McKinley, Jenifer M; Meadows, Gary G

    2011-03-01

    We previously found that chronic alcohol consumption (20% w/v in drinking water) that models the level consumed by human alcoholics, when administered to female C57BL/6 mice inhibits B16BL6 melanoma metastasis to the lung; however, the mechanism is not known. Chronic alcohol consumption increases IFN-γ producing NK, NKT, CD4(+), and CD8(+) T cells. To examine the impact of IFN-γ on metastasis, we inoculated B16BL6 melanoma cells i.v. into control and chronic alcohol drinking IFN-γ knockout (KO) mice. Knockout of the ifn-γ gene abrogated the anti-metastatic effects associated with alcohol consumption. We examined metastasis in common gamma-chain (γC) KO mice, which are deficient in NK, NKT and CD8(+) T cells, and in Vα14Jα281(-/-) KO mice, which are deficient in invariant NKT (iNKT) cells, in order to assess the importance of specific IFN-γ producing cell types to this effect. We found that the antimetastatic effect of alcohol was still present in γC KO mice and also in γC KO mice depleted of Gr-1(+) cells. Knockout of iNKT cells reduced the degree but not the antimetastatic effect associated with alcohol. These results indicate that the antimetastatic effect induced by chronic alcohol consumption is IFN-γ dependent and that multiple IFN-γ producing cell types contribute to this effect. PMID:21234656

  14. The Natural Product Phyllanthusmin C Enhances IFN-γ Production by Human Natural Killer Cells through Upregulation of TLR-Mediated NF-κB Signaling

    PubMed Central

    Deng, Youcai; Chu, Jianhong; Ren, Yulin; Fan, Zhijin; Ji, Xiaotian; Mundy, Bethany; Yuan, Shunzong; Hughes, Tiffany; Zhang, Jianying; Cheema, Baljash; Camardo, Andrew T.; Xia, Yong; Wu, Lai-Chu; Wang, Li-Shu; He, Xiaoming; Kinghorn, A. Douglas; Li, Xiaohui; Caligiuri, Michael A; Yu, Jianhua

    2014-01-01

    Natural products are a major source for cancer drug development. NK cells are a critical component of innate immunity with the capacity to destroy cancer cells, cancer initiating cells, and clear viral infections. However, few reports describe a natural product that selectively stimulates NK cell IFN-γ production and unravel a mechanism of action. In this study, through screening, we found that a natural product, phyllanthusmin C (PL-C), alone enhanced IFN-γ production by human NK cells. PL-C also synergized with IL-12, even at the low cytokine concentration of 0.1 mg/ml, and stimulated IFN-γ production in both human CD56bright and CD56dim NK cell subsets. Mechanistically, TLR1 and/or TLR6 mediated PL-C’s activation of the NF-κB p65 subunit that in turn bound to the proximal promoter of IFNG and subsequently resulted in increased IFN-γ production in NK cells. However, IL-12/IL-15 receptors and their related STAT signaling pathways were not significantly modulated by PL-C. PL-C induced little or no T cell IFN-γ production or NK cell cytotoxicity. Collectively, we identify a natural product with the capacity to selectively activate human NK cell IFN-γ. Given the role of IFN-γ in immune surveillance, additional studies to understand the role of this natural product in prevention of cancer or infection in select populations are warranted. PMID:25122922

  15. CD4 T Cell-Derived IFN-γ Plays a Minimal Role in Control of Pulmonary Mycobacterium tuberculosis Infection and Must Be Actively Repressed by PD-1 to Prevent Lethal Disease

    PubMed Central

    Sakai, Shunsuke; Kauffman, Keith D.; Sallin, Michelle A.; Sharpe, Arlene H.; Young, Howard A.; Ganusov, Vitaly V.; Barber, Daniel L.

    2016-01-01

    IFN-γ–producing CD4 T cells are required for protection against Mycobacterium tuberculosis (Mtb) infection, but the extent to which IFN-γ contributes to overall CD4 T cell-mediated protection remains unclear. Furthermore, it is not known if increasing IFN-γ production by CD4 T cells is desirable in Mtb infection. Here we show that IFN-γ accounts for only ~30% of CD4 T cell-dependent cumulative bacterial control in the lungs over the first six weeks of infection, but >80% of control in the spleen. Moreover, increasing the IFN-γ–producing capacity of CD4 T cells by ~2 fold exacerbates lung infection and leads to the early death of the host, despite enhancing control in the spleen. In addition, we show that the inhibitory receptor PD-1 facilitates host resistance to Mtb by preventing the detrimental over-production of IFN-γ by CD4 T cells. Specifically, PD-1 suppressed the parenchymal accumulation of and pathogenic IFN-γ production by the CXCR3+KLRG1-CX3CR1- subset of lung-homing CD4 T cells that otherwise mediates control of Mtb infection. Therefore, the primary role for T cell-derived IFN-γ in Mtb infection is at extra-pulmonary sites, and the host-protective subset of CD4 T cells requires negative regulation of IFN-γ production by PD-1 to prevent lethal immune-mediated pathology. PMID:27244558

  16. CD4 T Cell-Derived IFN-γ Plays a Minimal Role in Control of Pulmonary Mycobacterium tuberculosis Infection and Must Be Actively Repressed by PD-1 to Prevent Lethal Disease.

    PubMed

    Sakai, Shunsuke; Kauffman, Keith D; Sallin, Michelle A; Sharpe, Arlene H; Young, Howard A; Ganusov, Vitaly V; Barber, Daniel L

    2016-05-01

    IFN-γ-producing CD4 T cells are required for protection against Mycobacterium tuberculosis (Mtb) infection, but the extent to which IFN-γ contributes to overall CD4 T cell-mediated protection remains unclear. Furthermore, it is not known if increasing IFN-γ production by CD4 T cells is desirable in Mtb infection. Here we show that IFN-γ accounts for only ~30% of CD4 T cell-dependent cumulative bacterial control in the lungs over the first six weeks of infection, but >80% of control in the spleen. Moreover, increasing the IFN-γ-producing capacity of CD4 T cells by ~2 fold exacerbates lung infection and leads to the early death of the host, despite enhancing control in the spleen. In addition, we show that the inhibitory receptor PD-1 facilitates host resistance to Mtb by preventing the detrimental over-production of IFN-γ by CD4 T cells. Specifically, PD-1 suppressed the parenchymal accumulation of and pathogenic IFN-γ production by the CXCR3+KLRG1-CX3CR1- subset of lung-homing CD4 T cells that otherwise mediates control of Mtb infection. Therefore, the primary role for T cell-derived IFN-γ in Mtb infection is at extra-pulmonary sites, and the host-protective subset of CD4 T cells requires negative regulation of IFN-γ production by PD-1 to prevent lethal immune-mediated pathology. PMID:27244558

  17. IFN-γ Production Depends on IL-12 and IL-18 Combined Action and Mediates Host Resistance to Dengue Virus Infection in a Nitric Oxide-Dependent Manner

    PubMed Central

    Cisalpino, Daniel; Amaral, Flávio A.; Souza, Patrícia R. S.; Souza, Rafael S.; Ryffel, Bernhard; Vieira, Leda Q.; Silva, Tarcília A.; Atrasheuskaya, Alena; Ignatyev, George; Sousa, Lirlândia P.; Souza, Danielle G.; Teixeira, Mauro M.

    2011-01-01

    Dengue is a mosquito-borne disease caused by one of four serotypes of Dengue virus (DENV-1–4). Severe dengue infection in humans is characterized by thrombocytopenia, increased vascular permeability, hemorrhage and shock. However, there is little information about host response to DENV infection. Here, mechanisms accounting for IFN-γ production and effector function during dengue disease were investigated in a murine model of DENV-2 infection. IFN-γ expression was greatly increased after infection of mice and its production was preceded by increase in IL-12 and IL-18 levels. In IFN-γ−/− mice, DENV-2-associated lethality, viral loads, thrombocytopenia, hemoconcentration, and liver injury were enhanced, when compared with wild type-infected mice. IL-12p40−/− and IL-18−/− infected-mice showed decreased IFN-γ production, which was accompanied by increased disease severity, higher viral loads and enhanced lethality. Blockade of IL-18 in infected IL-12p40−/− mice resulted in complete inhibition of IFN-γ production, greater DENV-2 replication, and enhanced disease manifestation, resembling the response seen in DENV-2-infected IFN-γ−/− mice. Reduced IFN-γ production was associated with diminished Nitric Oxide-synthase 2 (NOS2) expression and NOS2−/− mice had elevated lethality, more severe disease evolution and increased viral load after DENV-2 infection. Therefore, IL-12/IL-18-induced IFN-γ production and consequent NOS2 induction are of major importance to host resistance against DENV infection. PMID:22206036

  18. LAP-like process as an immune mechanism downstream of IFN-γ in control of the human malaria Plasmodium vivax liver stage.

    PubMed

    Boonhok, Rachasak; Rachaphaew, Nattawan; Duangmanee, Apisak; Chobson, Pornpimol; Pattaradilokrat, Sittiporn; Utaisincharoen, Pongsak; Sattabongkot, Jetsumon; Ponpuak, Marisa

    2016-06-21

    IFN-γ is a major regulator of immune functions and has been shown to induce liver-stage Plasmodium elimination both in vitro and in vivo. The molecular mechanism responsible for the restriction of liver-stage Plasmodium downstream of IFN-γ remains uncertain, however. Autophagy, a newly described immune defense mechanism, was recently identified as a downstream pathway activated in response to IFN-γ in the control of intracellular infections. We thus hypothesized that the killing of liver-stage malarial parasites by IFN-γ involves autophagy induction. Our results show that whereas IFN-γ treatment of human hepatocytes activates autophagy, the IFN-γ-mediated restriction of liver-stage Plasmodium vivax depends only on the downstream autophagy-related proteins Beclin 1, PI3K, and ATG5, but not on the upstream autophagy-initiating protein ULK1. In addition, IFN-γ enhanced the recruitment of LC3 onto the parasitophorous vacuole membrane (PVM) and increased the colocalization of lysosomal vesicles with P. vivax compartments. Taken together, these data indicate that IFN-γ mediates the control of liver-stage P. vivax by inducing a noncanonical autophagy pathway resembling that of LC3-associated phagocytosis, in which direct decoration of the PVM with LC3 promotes the fusion of P. vivax compartments with lysosomes and subsequent killing of the pathogen. Understanding the hepatocyte response to IFN-γ during Plasmodium infection and the roles of autophagy-related proteins may provide an urgently needed alternative strategy for the elimination of this human malaria. PMID:27185909

  19. Soluble IL-6 Receptor and IL-27 Subunit p28 Protein Complex Mediate the Antiviral Response through the Type III IFN Pathway.

    PubMed

    Yang, Xiaodan; Hao, Hua; Xia, Zhangchuan; Xu, Gang; Cao, Zhongying; Chen, Xueyuan; Liu, Shi; Zhu, Ying

    2016-09-15

    Previously, we demonstrated that the soluble IL-6R (sIL-6R) plays an important role in the host antiviral response through induction of type I IFN and sIL-6R-mediated antiviral action via the IL-27 subunit p28; however, the mechanism that underlies sIL-6R and p28 antiviral action and whether type III IFN is involved remain unknown. In this study, we constructed a sIL-6R and p28 fusion protein (sIL-6R/p28 FP) and demonstrated that the fusion protein has stronger antiviral activity than sIL-6R alone. Consequently, knockout of sIL-6R inhibited virus-triggered IFN-λ1 expression. In addition, sIL-6R/p28 FP associated with mitochondrial antiviral signaling protein and TNFR-associated factor 6, the retinoic acid-inducible gene I adapter complex, and the antiviral activity mediated by sIL-6R/p28 FP was dependent on mitochondrial antiviral signaling protein. Furthermore, significantly reduced binding of p50/p65 and IFN regulatory factor 3 to the IFN-λ1 promoter was observed in sIL-6R knockout cells compared with the control cells. Interestingly, a novel heterodimer of c-Fos and activating transcription factor 1 was identified as a crucial transcriptional activator of IFN-λ1 The sIL-6R/p28 FP upregulated IFN-λ1 expression by increasing the binding abilities of c-Fos and activating transcription factor 1 to the IFN-λ1 promoter via the p38 MAPK signaling pathway. In conclusion, these results demonstrate the important role of sIL-6R/p28 FP in mediating virus-induced type III IFN production. PMID:27527594

  20. JUNB/AP-1 controls IFN-γ during inflammatory liver disease

    PubMed Central

    Thomsen, Martin K.; Bakiri, Latifa; Hasenfuss, Sebastian C.; Hamacher, Rainer; Martinez, Lola; Wagner, Erwin F.

    2013-01-01

    Understanding the molecular pathogenesis of inflammatory liver disease is essential to design efficient therapeutic approaches. In hepatocytes, the dimeric transcription factor c-JUN/AP-1 is a major mediator of cell survival during hepatitis, although functions for other JUN proteins in liver disease are less defined. Here, we found that JUNB was specifically expressed in human and murine immune cells during acute liver injury. We analyzed the molecular function of JUNB in experimental models of hepatitis, including administration of concanavalin A (ConA) or α-galactosyl-ceramide, which induce liver inflammation and injury. Mice specifically lacking JUNB in hepatocytes displayed a mild increase in ConA-induced liver damage. However, targeted deletion of Junb in immune cells and hepatocytes protected against hepatitis in experimental models that involved NK/NKT cells. The absence of JUNB in immune cells decreased IFN-γ expression and secretion from NK and NKT cells, leading to reduced STAT1 pathway activation. Systemic IFN-γ treatment or adenovirus-based IRF1 delivery to Junb-deficient mice restored hepatotoxicity, and we demonstrate that Ifng is a direct transcriptional target of JUNB. These findings demonstrate that JUNB/AP-1 promotes cell death during acute hepatitis by regulating IFN-γ production in NK and NKT cells and thus functionally antagonizes the hepatoprotective function of c-JUN/AP-1 in hepatocytes. PMID:24200694

  1. IFN-γ mediates graft-versus-breast cancer effects via enhancing cytotoxic T lymphocyte activity.

    PubMed

    Zhao, Qianjie; Tong, Lingling; He, Ningning; Feng, Guowei; Leng, Liang; Sun, Weijun; Xu, Yang; Wang, Yuebing; Xiang, Rong; Li, Zongjin

    2014-08-01

    Previous studies have demonstrated the beneficial effect of graft-versus-tumor (GVT) following hematopoietic stem cell transplantation (HSCT) on the incidence of leukemia relapse and the overall survival rate of patients with leukemia; however, detailed mechanisms underlying the effects GVT exhibits on solid tumors following allogeneic HSCT are yet to be elucidated. The aim of the present study was to investigate the immune mechanism underlying the effect of interferon (IFN)-γ on GVT following allogeneic HSCT in breast cancer therapy. An in situ breast cancer mouse model was established by injecting 5×10(4) 4T1 cells into the mammary fat pads of BALB/c mice. The 4T1 cells were transfected with the firefly luciferase reporter gene in order to monitor the tumor progression in real time. An allogeneic HSCT model was then established by transplanting bone marrow mononuclear cells from C57BL/6 mice to the BALB/c mice. To investigate the influence of T lymphocyte proliferation following allogeneic bone marrow transplantation, the levels of CD3(+)CD8(+) cytotoxic T lymphocytes (CTLs) and CD4(+)CD25(+) regulatory T cells were determined. In addition, IFN-γ and granzyme B expression levels in splenic lymphocytes were analyzed using flow cytometry. Allogeneic HSCT was found to significantly promote the proliferation and cytotoxicity of CTLs and suppress the growth of breast cancer. Furthermore, the secretory levels of IFN-γ and granzyme B by T cells were elevated following allogeneic HSCT. These results indicated that alloreactive T cells increased the secretion of IFN-γ, which promoted the alloresponse of donor CTLs. In addition, the CTLs produced granzyme B, which exerted a tumor suppressive effect. PMID:25009582

  2. Anti-tumor immunity elicited by direct intratumoral administration of a recombinant adenovirus expressing either IL-28A/IFN-λ2 or IL-29/IFN-λ1.

    PubMed

    Hasegawa, K; Tagawa, M; Takagi, K; Tsukamoto, H; Tomioka, Y; Suzuki, T; Nishioka, Y; Ohrui, T; Numasaki, M

    2016-08-01

    Interleukin (IL)-28A/interferon (IFN)-λ2 and IL-29/IFN-λ1 have been demonstrated to elicit direct and indirect anti-tumor actions. In this study, we constructed an adenovirus vector expressing either IL-28A/IFN-λ2 (AdIL-28A) or IL-29/IFN-λ1 (AdIL-29) to evaluate the therapeutic properties of intratumoral injection of recombinant adenovirus to apply for the clinical implementation of cancer gene therapy. Despite the lack of an anti-proliferative effect on MCA205 and B16-F10 cells, a retarded growth of established subcutaneous tumors was observed following multiple injections of either AdIL-28A or AdIL-29 when compared with AdNull. In vivo cell depletion experiments displayed that both NK cells and CD8(+) T cells have a major role in AdIL-28A-mediated tumor growth suppression. A significant increase in the number of infiltrating CD8(+) T cells into the tumors treated with either AdIL-28A or AdIL-29 was observed. Moreover, specific anti-tumor cytotoxic T lymphocyte reactivity was detected in spleen cells from animals treated with either AdIL-28A or AdIL-29. In IFN-γ-deficient mice, anti-tumor activities of AdIL-28A were completely impaired, indicating that IFN-γ is critically involved in the tumor growth inhibition triggered by AdIL-28A. IL-12 provided a synergistic anti-tumor effect when combined with AdIL-28A. These results indicate that AdIL-28A and AdIL-29 could be successfully utilized as an alternative cancer immunogene therapy. PMID:27561689

  3. FACTORS INFLUENCING AGE AND STRAIN-RELATED SUSCEPTIBILITY TO 3-METHYLCHOLANTHRENE CARCINOGENICITY

    EPA Science Inventory

    Fetal mice are more sensitive to chemical carcinogens than are adults. Further, some strains of mice are more susceptible to chemical carcinogens than others. We have been conducting studies to understand the interactions between age and genetic background underlying these suscep...

  4. Effects of IFN-γ on intracellular trafficking and activity of macrophage NADPH oxidase flavocytochrome b558

    PubMed Central

    Casbon, Amy-Jo; Long, Matthew E.; Dunn, Kenneth W.; Allen, Lee-Ann H.; Dinauer, Mary C.

    2012-01-01

    Flavocytochrome b558, the catalytic core of the phagocyte NADPH oxidase (NOX2), mediates electron transfer from NADPH to molecular oxygen to generate superoxide, the precursor of highly ROS for host defense. Flavocytochrome b558 is an integral membrane heterodimer consisting of a large glycosylated subunit, gp91phox, and a smaller subunit, p22phox. We recently showed in murine macrophages that flavocytochrome b558 localizes to the PM and Rab11-positive recycling endosomes, whereas in primary hMDMs, gp91phox and p22phox reside in the PM and the ER. The antimicrobial activity of macrophages, including ROS production, is greatly enhanced by IFN-γ, but how this is achieved is incompletely understood. To further define the mechanisms by which IFN-γ enhances macrophage NADPH oxidase activity, we evaluated changes in flavocytochrome b558 expression and localization, along with NADPH oxidase activity, in IFN-γ stimulated RAW 264.7 cells and primary murine BMDMs and hMDMs. We found that enhanced capacity for ROS production is, in part, a result of increased protein expression of gp91phox and p22phox but also demonstrate that IFN-γ induced a shift in the predominant localization of gp91phox and p22phox from intracellular membrane compartments to the PM. Our results are the first to show that a cytokine can change the distribution of macrophage flavocytochrome b558 and provide a potential, new mechanism by which IFN-γ modulates macrophage antimicrobial activity. Altogether, our data suggest that the mechanisms by which IFN-γ regulates antimicrobial activity of macrophages are more complex than previously appreciated. PMID:22822009

  5. Characteristics of Schistosoma japonicum infection induced IFN-γ and IL-4 co-expressing plasticity Th cells.

    PubMed

    Chen, Dianhui; Xie, Hongyan; Cha, Hefei; Qu, Jiale; Wang, Mei; Li, Lu; Yu, Sifei; Wu, Changyou; Tang, Xiaoping; Huang, Jun

    2016-09-01

    Schistosoma japonicum infection can induce granulomatous inflammation and cause tissue damage in the mouse liver. The cytokine secretion profile of T helper (Th) cells depends on both the nature of the activating stimulus and the local microenvironment (e.g. cytokines and other soluble factors). In the present study, we found an accumulation of large numbers of IFN-γ(+)  IL-4(+)  CD4(+) T cells in mouse livers. This IFN-γ(+)  IL-4(+) cell population increased from 0·68 ± 0·57% in uninfected mice to 7·05 ± 3·0% by week 4 following infection and to 9·6 ± 5·28% by week 6, before decreasing to 6·3 ± 5·9% by week 8 in CD4 T cells. Moreover, IFN-γ(+)  IL-4(+) Th cells were also found in mouse spleen and mesenteric lymph nodes 6 weeks after infection. The majority of the IFN-γ(+)  IL-4(+) Th cells were thought to be related to a state of immune activation, and some were memory T cells. Moreover, we found that these S. japonicum infection-induced IFN-γ(+)  IL-4(+) cells could express interleukin-2 (IL-2), IL-9, IL-17 and high IL-10 levels at 6 weeks after S. japonicum infection. Taken together, our data suggest the existence of a population of IFN-γ(+)  IL-4(+) plasticity effector/memory Th cells following S. japonicum infection in C57BL/6 mice. PMID:27242265

  6. A novel glycolipid antigen for NKT cells that preferentially induces IFN-γ production

    PubMed Central

    Birkholz, Alysia M.; Girardi, Enrico; Wingender, Gerhard; Khurana, Archana; Wang, Jing; Zhao, Meng; Zahner, Sonja; Illarionov, Petr A.; Wen, Xiangshu; Li, Michelle; Yuan, Weiming; Porcelli, Steven A.; Besra, Gurdyal S.; Zajonc, Dirk M.; Kronenberg, Mitchell

    2015-01-01

    Here we characterize a novel Ag for invariant natural killer T-cells (iNKT cells) capable of producing an especially robust Th1 response. This glycosphingolipid (GSL), DB06-1, is similar in chemical structure to the well-studied α-galactosylceramide (αGalCer), the only change being in a single atom, the substitution of a carbonyl oxygen with a sulfur atom. Although DB06-1 is not a more effective Ag in vitro, the small chemical change has a marked impact on the ability of this lipid Ag to stimulate iNKT cells in vivo, with increased IFN-γ production at 24 h compared to αGalCer, increased IL-12, and increased activation of NK cells to produce IFN-γ. These changes are correlated with an enhanced ability of DB06-1 to load in the CD1d molecules expressed by DCs in vivo. Moreover, structural studies suggest a tighter fit into the CD1d binding groove by DB061 compared to αGalCer. Surprisingly, when iNKT cells previously exposed to DB06-1 are restimulated weeks later, they have greatly increased IL-10 production. Our data are therefore consistent with a model whereby augmented and or prolonged presentation of a glycolipid Ag leads to increased activation of NK cells and a Th1-skewed immune response, which may result in part from enhanced loading into CD1d. Furthermore, our data suggest that strong antigenic stimulation in vivo may lead to the expansion of IL-10 producing iNKT cells, which could counteract the benefits of increased, early IFN-γ production. PMID:26078271

  7. A Novel Glycolipid Antigen for NKT Cells That Preferentially Induces IFN-γ Production.

    PubMed

    Birkholz, Alysia M; Girardi, Enrico; Wingender, Gerhard; Khurana, Archana; Wang, Jing; Zhao, Meng; Zahner, Sonja; Illarionov, Petr A; Wen, Xiangshu; Li, Michelle; Yuan, Weiming; Porcelli, Steven A; Besra, Gurdyal S; Zajonc, Dirk M; Kronenberg, Mitchell

    2015-08-01

    In this article, we characterize a novel Ag for invariant NKT (iNKT) cells capable of producing an especially robust Th1 response. This glycosphingolipid, DB06-1, is similar in chemical structure to the well-studied α-galactosylceramide (αGalCer), with the only change being a single atom: the substitution of a carbonyl oxygen with a sulfur atom. Although DB06-1 is not a more effective Ag in vitro, the small chemical change has a marked impact on the ability of this lipid Ag to stimulate iNKT cells in vivo, with increased IFN-γ production at 24 h compared with αGalCer, increased IL-12, and increased activation of NK cells to produce IFN-γ. These changes are correlated with an enhanced ability of DB06-1 to load in the CD1d molecules expressed by dendritic cells in vivo. Moreover, structural studies suggest a tighter fit into the CD1d binding groove by DB06-1 compared with αGalCer. Surprisingly, when iNKT cells previously exposed to DB06-1 are restimulated weeks later, they have greatly increased IL-10 production. Therefore, our data are consistent with a model whereby augmented and or prolonged presentation of a glycolipid Ag leads to increased activation of NK cells and a Th1-skewed immune response, which may result, in part, from enhanced loading into CD1d. Furthermore, our data suggest that strong antigenic stimulation in vivo may lead to the expansion of IL-10-producing iNKT cells, which could counteract the benefits of increased early IFN-γ production. PMID:26078271

  8. Cytotoxic response of ovarian cancer cell lines to IFN-γ is associated with sustained induction of IRF-1 and p21 mRNA

    PubMed Central

    Burke, F; Smith, P D; Crompton, M R; Upton, C; Balkwill, F R

    1999-01-01

    Intereferon-γ (IFN-γ) has some anti-tumour activity in human ovarian cancer. This cytokine inhibited proliferation in three of four ovarian cancer cell lines in vitro. We then compared the action of IFN-γ in two cell lines, one sensitive and one resistant to its growth inhibitory effects. IFN-γ signalling appeared normal in both cell lines, with stat1 DNA binding activity detectable at 30 min. Continuous exposure to IFN-γ for 2–3 days was necessary for an irreversible effect on cell growth and apoptosis in cells sensitive to growth inhibition. During this time there was an increase in mRNA for the CKI p21, but no alterations in mRNA levels for other members of the CKI family. Maintenance of p21 mRNA required continuous mRNA synthesis. mRNA for the transcription factor IRF-1 was also induced in growth inhibited cells with similar kinetics to those observed for p21. Maximal induction of both p21 and IRF-1 mRNA was observed after 2–3 days IFN-γ exposure as the cells became committed to cell death. There was also a rapid increase in p21 and IRF-1 mRNA in cells resistant to the growth inhibitory effects of IFN-γ, but this increase was not maintained. Thus, continuous interaction with the IFN-γ receptor, together with a sustained induction of p21 and IRF-1, is associated with growth inhibitory and apoptotic effects of IFN-γ in ovarian cancer cells. © 1999 Cancer Research Campaign PMID:10376977

  9. Dendritic cells and NK cells stimulate bystander T cell activation in response to TLR agonists through secretion of IFN-alpha beta and IFN-gamma.

    PubMed

    Kamath, Arun T; Sheasby, Christopher E; Tough, David F

    2005-01-15

    Recognition of conserved features of infectious agents by innate pathogen receptors plays an important role in initiating the adaptive immune response. We have investigated early changes occurring among T cells after injection of TLR agonists into mice. Widespread, transient phenotypic activation of both naive and memory T cells was observed rapidly after injection of molecules acting through TLR3, -4, -7, and -9, but not TLR2. T cell activation was shown to be mediated by a combination of IFN-alphabeta, secreted by dendritic cells (DCs), and IFN-gamma, secreted by NK cells; notably, IFN-gamma-secreting NK cells expressed CD11c and copurified with DCs. Production of IFN-gamma by NK cells could be stimulated by DCs from TLR agonist-injected mice, and although soluble factors secreted by LPS-stimulated DCs were sufficient to induce IFN-gamma, maximal IFN-gamma production required both direct contact of NK cells with DCs and DC-secreted cytokines. In vitro, IFN-alphabeta, IL-18, and IL-12 all contributed to DC stimulation of NK cell IFN-gamma, whereas IFN-alphabeta was shown to be important for induction of T cell bystander activation and NK cell IFN-gamma production in vivo. The results delineate a pathway involving innate immune mediators through which TLR agonists trigger bystander activation of T cells. PMID:15634897

  10. Evasion of IFN-γ Signaling by Francisella novicida Is Dependent upon Francisella Outer Membrane Protein C

    PubMed Central

    Nallaparaju, Kalyan C.; Yu, Jieh-Juen; Rodriguez, Stephen A.; Zogaj, Xhavit; Manam, Srikanth; Guentzel, M. Neal; Seshu, Janakiram; Murthy, Ashlesh K.; Chambers, James P.; Klose, Karl E.; Arulanandam, Bernard P.

    2011-01-01

    Background Francisella tularensis is a Gram-negative facultative intracellular bacterium and the causative agent of the lethal disease tularemia. An outer membrane protein (FTT0918) of F. tularensis subsp. tularensis has been identified as a virulence factor. We generated a F. novicida (F. tularensis subsp. novicida) FTN_0444 (homolog of FTT0918) fopC mutant to study the virulence-associated mechanism(s) of FTT0918. Methods and Findings The ΔfopC strain phenotype was characterized using immunological and biochemical assays. Attenuated virulence via the pulmonary route in wildtype C57BL/6 and BALB/c mice, as well as in knockout (KO) mice, including MHC I, MHC II, and µmT (B cell deficient), but not in IFN-γ or IFN-γR KO mice was observed. Primary bone marrow derived macrophages (BMDM) prepared from C57BL/6 mice treated with rIFN-γ exhibited greater inhibition of intracellular ΔfopC than wildtype U112 strain replication; whereas, IFN-γR KO macrophages showed no IFN-γ-dependent inhibition of ΔfopC replication. Moreover, phosphorylation of STAT1 was downregulated by the wildtype strain, but not the fopC mutant, in rIFN-γ treated macrophages. Addition of NG-monomethyl-L-arginine, an NOS inhibitor, led to an increase of ΔfopC replication to that seen in the BMDM unstimulated with rIFN-γ. Enzymatic screening of ΔfopC revealed aberrant acid phosphatase activity and localization. Furthermore, a greater abundance of different proteins in the culture supernatants of ΔfopC than that in the wildtype U112 strain was observed. Conclusions F. novicida FopC protein facilitates evasion of IFN-γ-mediated immune defense(s) by down-regulation of STAT1 phosphorylation and nitric oxide production, thereby promoting virulence. Additionally, the FopC protein also may play a role in maintaining outer membrane stability (integrity) facilitating the activity and localization of acid phosphatases and other F. novicida cell components. PMID:21483828

  11. The gamma interferon (IFN-gamma) mimetic peptide IFN-gamma (95-133) prevents encephalomyocarditis virus infection both in tissue culture and in mice.

    PubMed

    Mujtaba, Mustafa G; Patel, Chintak B; Patel, Ravi A; Flowers, Lawrence O; Burkhart, Marjorie A; Waiboci, Lilian W; Martin, James; Haider, Mohammad I; Ahmed, Chulbul M; Johnson, Howard M

    2006-08-01

    We have demonstrated previously that the C-terminal gamma interferon (IFN-gamma) mimetic peptide consisting of residues 95 to 133 [IFN-gamma(95-133)], which contains the crucial IFN-gamma nuclear localization sequence (NLS), has antiviral activity in tissue culture. Here we evaluate the efficacy of this peptide and its derivatives first in vitro and then in an animal model of lethal viral infection with the encephalomyocarditis (EMC) virus. Deletion of the NLS region from the IFN-gamma mimetic peptide IFN-gamma(95-133) resulted in loss of antiviral activity. However, the NLS region does not have antiviral activity in itself. Replacing the NLS region of IFN-gamma(95-133) with the NLS region of the simian virus 40 large T antigen retains the antiviral activity in tissue culture. IFN-gamma(95-133) prevented EMC virus-induced lethality in mice in a dose-dependent manner compared to controls. Mice treated with IFN-gamma(95-133) had no or low EMC virus titers in their internal organs, whereas control mice had consistently high viral titers, especially in the heart tissues. Injection of B8R protein, which is encoded by poxviruses as a defense mechanism to neutralize host IFN-gamma, did not inhibit IFN-gamma(95-133) protection against a lethal dose of EMC virus, whereas mice treated with rat IFN-gamma were not protected. The data presented here show that the IFN-gamma mimetic peptide IFN-gamma(95-133) prevents EMC virus infection in vivo and in vitro and may have potential against other lethal viruses, such as the smallpox virus, which encodes the B8R protein. PMID:16893996

  12. Molecular characterization of IFN-T expressed in buffalo embryonic trophoblasts and expression of recombinant BuIFN-T1a2 and BuIFN-T8 isoforms in E. coli.

    PubMed

    Saugandhika, Shrabani; Sharma, Vishal; Malik, Hrudananda; Mohapatra, Sushil Kumar; Bondre, Vijay P; Kumar, Sudarshan; Mohanty, Ashok Kumar; Malakar, Dhruba

    2016-06-01

    Interferon tau (IFN-T) acts as a signaling molecule for maternal recognition of pregnancy (MRP) in ruminants. Aim of the present study was to identify various Buffalo Interferon tau (BuIFN-T) transcripts in buffalo trophoblast, phylogenetic comparison of these sequences with known mRNA sequences of buffalo, bovine, caprine and ovine and to express and purify the recombinant BuIFN-T (rBuIFN-T) isoforms. Following RNA extraction from trophectodermal cells, RT-PCR was performed using Ifn-t gene specific primers. 13 distinct cDNA variants encoding eight different BuIFN-T proteins were identified. BuIFN-T1a2 and BuIFN-T8 were expressed in prokaryotic expression system at 37 °C, 25 °C and 16 °C with 1 mM IPTG for 12 h and the recombinant proteins expressed at 16 °C were partially purified by Immobilised Metal Affinity Chromatography (IMAC). BuIFN-T isoforms have greater nucleotide and amino acid homology with caprine (98-100%, 96-100%), ovine (94-97%, 90-95%) and bovine (89.6-90.6%, 82-86%). These novel BuIFN-T isoforms contained pronounced nucleotide and amino acid sequence identity with one another (99.1-99.8%, 98-99%) but moderate sequence identity with previously identified buffalo IFN-T (90-92%, 82-86%). Solubility of expressed recombinant isoforms (rBuIFN-T1a2 and rBuIFN-T8) was highest at 16 °C. In conclusion, 13 distinct Ifn-t gene variants exist in trophectoderm of in vitro developed buffalo blastocysts that encode eight different proteins. rBuIFN-T1a2 and rBuIFN-T8 were successfully expressed in soluble form in Escherichia coli expression system at 16 °C with 1 mM IPTG and the resulting recombinant proteins were partially purified by IMAC. PMID:26876002

  13. Bioinformatics analysis of organizational and expressional characterizations of the IFNs, IRFs and CRFBs in grass carp Ctenopharyngodon idella.

    PubMed

    Liao, Zhiwei; Wan, Quanyuan; Su, Jianguo

    2016-08-01

    Interferons (IFNs) play crucial roles in the immune response of defense against viral infection and bacteria invasion. In the present study, we systematically identified and characterized the IFNs, their regulatory factors (Interferon Regulatory Factors, IRFs) and receptors (Cytokine Receptor Family B, CRFBs) in grass carp (Ctenopharyngodon idella). Grass carp IFNs can be classified into type I IFN (IFN-I) and type II IFN (IFN-II) like other teleosts. IFN-I consist of two groups with two (group I) or four (group II) cysteines in the mature peptide and can be further divided into three subgroups (IFN-a, -c and -d), containing four members: IFN1, IFN2, IFN3, IFN4 in grass carp. IFN-II contain two members, IFNγ2 with the similarity to mammalian IFNγ and a cyprinid specific IFNγ1 (IFNγ-rel) molecule. mRNA expression analyses of IFNs discovered that IFN1 and IFN-II were sustainably expressed in many tissues, while other IFN members were transiently expressed in specific tissues and time points. In the immune response, IFN transcriptions are primarily regulated through multiple IRFs after grass carp reovirus (GCRV) challenge. IRF family possess thirteen members in grass carp, which can be further divided into four subfamilies (IRF-1, -3, -4 and -5 subfamily), each of them plays different roles in the innate and adaptive immunity via various signaling pathways to interact with IFNs (mainly IFN-I). IFNs have to bind receptors (CRFBs) to perform their functions. CRFBs as IFN receptors contain six members in grass carp. The structure and expression characterizations of IFNs, IRFs and CRFBs were analyzed using bioinformatics tools. These results might provide basic data for the further functional research of IFN system, and deeply understand fish immune mechanisms against virus infection. PMID:27012995

  14. Type III interferon (IFN-lambda) antagonizes the antiviral activity of interferon-alpha in vitro.

    PubMed

    Bordi, L; Lalle, E; Lapa, D; Caglioti, C; Quartu, S; Capobianchi, M R; Castilletti, C

    2013-01-01

    Type III interferons (IFN-lambda) are the most recently discovered members of IFN family. Synergism between different IFN types is well established, but for type I and type III IFNs no conclusive evidence has been reported so far. Possible synergism/antagonism between IFN-alpha and IFN-lambda in the inhibition of virus replication (EMCV, WNV lineage 1 and 2, CHIKV and HSV-1), and in the activation of intracellular pathways of IFN response (MxA and 2'-5' OAS) was evaluated in different cell lines (Vero E6, A549 and Wish cells). The antiviral potency of IFN-lambda1 and -l2 was lower than that of IFN-alpha. When IFN-alpha and -lambda were used together, the Combination Index (CI) for virus inhibition was greater than 1 virtually for all virus/host cell systems, indicating antagonistic effect. Antagonism between IFN-alpha and -l was also observed for the induction of mRNA for both MxA and 2'-5'OAS. Elucidating the interplay between IFN-alpha and -lambda may help to better understand innate defence mechanisms against viral infections, including the molecular mechanisms underlying the influence of IL-28B polymorphisms in the response to HCV and other viral infections. PMID:24382181

  15. Production and secretion of interferon-gamma (IFN-gamma) in children with atopic dermatitis.

    PubMed Central

    Tang, M; Kemp, A

    1994-01-01

    IFN-gamma is known to be a major inhibitor of IgE synthesis in vitro. Recent studies demonstrating reduced production of IFN-gamma in children and adults with atopic dermatitis and elevated serum IgE suggest a similar role for this cytokine in vivo. The reasons for this reduced IFN-gamma production are not known. One possibility is that atopic individuals have a reduced population of cells producing IFN-gamma in vivo. Using a fluorescence-labelled antibody to detect intracellular IFN-gamma, the percentage of IFN-gamma-producing cells was determined in children with atopic dermatitis and in non-atopic controls. Children with atopic dermatitis had a greater percentage of IFN-gamma-producing cells in unstimulated cultures compared with controls, indicating in vivo activation of lymphocytes in the atopic group. This could reflect the significant degree of inflammation present in these children, or the presence of bacterial infection or colonization. Although secretion of IFN-gamma after stimulation with phorbol myristate acetate (PMA)/Ca was significantly lower in children with atopic dermatitis compared with controls, the percentage of IFN-gamma-producing cells in the stimulated cultures from this group was equivalent to controls. This demonstrates that the reduced ability of atopic children to secrete IFN-gamma in vitro does not relate to a lack of IFN-gamma-producing cells, but to a difference in the regulation of IFN-gamma production beyond the stage of signal transduction. PMID:8287610

  16. The HPV-16 E7 oncogene sensitizes malignant cells to IFN-alpha-induced apoptosis

    SciTech Connect

    Wang, Yisong

    2005-10-01

    Interferons (IFNs) exert antitumor effects in several human malignancies, but their mechanism of action is unclear. There is a great variability in sensitivity to IFN treatment depending on both tumor type and the individual patient. The reason for this variable sensitivity is not known. The fact that several IFN-induced anticellular effects are exerted through modulation of proto-oncogenes and tumor suppressor genes may indicate that the malignant genotype may be decisive in the cell's sensitivity to IFN. To determine if a deregulated oncogene could alter the cellular response to IFN, a mouse lymphoma cell line (J3D) was stably transfected with the viral human papillomavirus-16 (HPV-16) E7 oncogene. The E7-transfected cells and their respective mock-transfected sister clones were treated with IFN-{alpha} and examined for possible IFN-induced anticellular effects. We found that the E7-transfected clones were greatly sensitized to IFN-{alpha}-induced apoptosis compared with their mock-transfected counterparts. Induction of apoptosis in the transfected cells correlated with the ability of IFN to activate parts of the proapoptotic machinery specifically in these cells, including activation of caspases and the proapoptotic protein Bak. In summary, our data suggest that transfection of malignant cells with the E7 oncogene can sensitize them to IFN-{alpha}-induced apoptosis. This demonstrates that an oncogenic event may alter the cellular sensitivity to IFN and might also have implications for treatment of HPV related diseases with IFN.

  17. Toxoplasma Effector Recruits the Mi-2/NuRD Complex to Repress STAT1 Transcription and Block IFN-γ-Dependent Gene Expression.

    PubMed

    Olias, Philipp; Etheridge, Ronald D; Zhang, Yong; Holtzman, Michael J; Sibley, L David

    2016-07-13

    Interferon gamma (IFN-γ) is an essential mediator of host defense against intracellular pathogens, including the protozoan parasite Toxoplasma gondii. However, prior T. gondii infection blocks IFN-γ-dependent gene transcription, despite the downstream transcriptional activator STAT1 being activated and bound to cognate nuclear promoters. We identify the parasite effector that blocks STAT1-dependent transcription and show it is associated with recruitment of the Mi-2 nucleosome remodeling and deacetylase (NuRD) complex, a chromatin-modifying repressor. This secreted effector, toxoplasma inhibitor of STAT1-dependent transcription (TgIST), translocates to the host cell nucleus, where it recruits Mi-2/NuRD to STAT1-dependent promoters, resulting in altered chromatin and blocked transcription. TgIST is conserved across strains, underlying their shared ability to block IFN-γ-dependent transcription. TgIST deletion results in increased parasite clearance in IFN-γ-activated cells and reduced mouse virulence, which is restored in IFN-γ-receptor-deficient mice. These findings demonstrate the importance of both IFN-γ responses and the ability of pathogens to counteract these defenses. PMID:27414498

  18. A RIG-I 2CARD-MAVS200 Chimeric Protein Reconstitutes IFN-β Induction and Antiviral Response in Models Deficient in Type I IFN Response.

    PubMed

    Nistal-Villán, Estanislao; Rodríguez-García, Estefanía; Di Scala, Marianna; Ferrero-Laborda, Roberto; Olagüe, Cristina; Vales, África; Carte-Abad, Beatriz; Crespo, Irene; García-Sastre, Adolfo; Prieto, Jesús; Larrea, Esther; González-Aseguinolaza, Gloria

    2015-01-01

    RIG-I-like receptors (RLRs) are cellular sensor proteins that detect certain RNA species produced during viral infections. RLRs activate a signaling cascade that results in the production of IFN-β as well as several other cytokines with antiviral and proinflammatory activities. We explored the potential of different constructs based on RLRs to induce the IFN-β pathway and create an antiviral state in type I IFN-unresponsive models. A chimeric construct composed of RIG-I 2CARD and the first 200 amino acids of MAVS (2CARD-MAVS200) showed an enhanced ability to induce IFN-β when compared to other stimulatory constructs. Furthermore, this human chimeric construct showed a superior ability to activate IFN-β expression in cells from various species. This construct was found to overcome the restrictions of blocking IFN-β induction or signaling by a number of viral IFN-antagonist proteins. Additionally, the antiviral activity of this chimera was demonstrated in influenza virus and HBV infection mouse models using adeno-associated virus (AAV) vectors as a delivery vehicle. We propose that AAV vectors expressing 2CARD-MAVS200 chimeric protein can reconstitute IFN-β induction and recover a partial antiviral state in different models that do not respond to recombinant IFN-β treatment. PMID:25966783

  19. Cytoplasmic STAT4 Promotes Antiviral Type I IFN Production by Blocking CHIP-Mediated Degradation of RIG-I.

    PubMed

    Zhao, Kai; Zhang, Qian; Li, Xia; Zhao, Dezhi; Liu, Yiqi; Shen, Qicong; Yang, Mingjin; Wang, Chunmei; Li, Nan; Cao, Xuetao

    2016-02-01

    Retinoic acid-inducible gene I (RIG-I) signaling is critical to host innate immune response against RNA virus infection. Numerous factors use different mechanisms to regulate RIG-I signaling. In this study, we report that STAT family member STAT4 promotes RIG-I-triggered type I IFN production in antiviral innate immunity. Silencing of STAT4 impaired IFN-β production in macrophages upon RNA virus infection, whereas overexpression of STAT4 enhanced RIG-I-induced IFN-β promoter activation and IFN-stimulated response element activity. Silencing of STAT4 increased degradation of RIG-I. Interestingly, during RNA virus infection STAT4 was found to be constantly present in cytoplasm of macrophages without Tyr(693) phosphorylation, which is required for its classical activation and nuclear translocation. Mechanistically, cytoplasmic STAT4 could interact with E3 ligase CHIP and block RIG-I and CHIP association, preventing CHIP-mediated proteasomal degradation of RIG-I via K48-linked ubiquitination. Our study provides a new manner for posttranslational regulation of RIG-I signaling and identifies a previously unknown function of cytoplasm-localized STAT4 in antiviral innate immunity. PMID:26695369

  20. Zebrafish Plzf transcription factors enhance early type I IFN response induced by two non-enveloped RNA viruses.

    PubMed

    Aleksejeva, E; Houel, A; Briolat, V; Levraud, J-P; Langevin, C; Boudinot, P

    2016-04-01

    The BTB-POZ transcription factor Promyelocytic Leukemia Zinc Finger (PLZF, or ZBTB16) has been recently identified as a major factor regulating the induction of a subset of Interferon stimulated genes in human and mouse. We show that the two co-orthologues of PLZF found in zebrafish show distinct expression patterns, especially in larvae. Although zbtb16a/plzfa and zbtb16b/plzfb are not modulated by IFN produced during viral infection, their over-expression increases the level of the early type I IFN response, at a critical phase in the race between the virus and the host response. The effect of Plzfb on IFN induction was also detectable after cell infection by different non-enveloped RNA viruses, but not after infection by the rhabdovirus SVCV. Our findings indicate that plzf implication in the regulation of type I IFN responses is conserved across vertebrates, but at multiple levels of the pathway and through different mechanisms. PMID:26719025

  1. Development of a Hyperglycosylated IFN Alfacon-1 (CIFN): Toward Bimonthly or Monthly Dosing for Antiviral Therapies.

    PubMed

    Taylor, Joshua S; Zhang, Qingling; Julander, Justin G; Stoycheva, Antitsa D; Tan, Hua; Moy, Christabel V; Chanda, Sushmita; Symons, Julian A; Beigelman, Leonid N; Blatt, Lawrence M; Hong, Jin

    2015-08-01

    Type 1 interferons (IFNs) have been shown to be efficacious against hepatitis C virus (HCV), hepatitis B virus (HBV), and some cancers with a significant drawback of short drug exposure. We have significantly improved the pharmacokinetic (PK) of consensus interferon (CIFN) by glycoengineering. We generated AL-624 by introducing 4 glycosylation sites. AL-624 was expressed, purified, and fractionated to yield 2-Gly, 3-Gly, and 4-Gly. In a rat PK study, AL-624 4-Gly exhibited a 6-fold increase of area under curve (AUC) and more than an 11-fold increase in time to half life (T1/2) over CIFN, suggesting the potential for weekly dosing (QW). In Yellow fever virus hamster model, QW of 4-Gly achieved similar efficacy to daily dosing (QD) CIFN and QW Peg-IFN-α-2a in overall survival rate and reduction of alanine aminotransferase (ALT) level. Further refinement resulted in development of AL-683 by addition of external glycosylation sites and its mouse homologue. AL-683 maintains undiminished biological potency in HCV replicon. In mouse PK/pharmacodynamic (PD) studies, AL-683 homologue has a ∼37-fold improvement in T1/2 and a ∼33-fold improvement in AUC when compared with the unglycosylated mouse IFN-α-1. Significantly improved PD responses were also observed. The significant improvement of AL-683 PK over AL-624 suggests a bimonthly dosing regimen for AL-683. The possibility for once-a-month dosing could be realized by further optimization of manufacturing conditions. PMID:25866898

  2. Transcriptional Dysregulation of Upstream Signaling of IFN Pathway in Chronic HCV Type 4 Induced Liver Fibrosis.

    PubMed

    Ibrahim, Marwa K; Salum, Ghada Maher; Bader El Din, Noha G; Dawood, Reham M; Barakat, Ahmed; Khairy, Ahmed; El Awady, Mostafa K

    2016-01-01

    IFN orchestrates the expression of various genes to halt hepatitis C virus (HCV) replication with the possibility of either reduced or increased liver fibrosis; due to controlled viral replication or overproduction of inflammatory mediators, repectively. In this study, we examined the transcriptional profiling of type I IFN related genes in HCV-chronically infected patients with varying degrees of liver fibrosis. PCR array was used to examine the expression of 84 type I IFN related genes in peripheral blood mononuclear cells (PBMCs) RNA from 12 treatment-naïve chronic HCV patients (5 F0-F1 and 7 F2-F4) and 5 healthy subjects. We further validated our results by quantitative real time PCR (qRT-PCR) in 103 treatment-naïve chronic HCV patients (43 F0-F1 and 60 F2-F4) and 15 controls. PCR array data revealed dysregulation in TLR7 pathway. The expression of TLR7 was decreased by 4 folds and MyD88 was increased by 3 folds in PBMCs of F2-F4 patients when compared to the healthy volunteers (p = 0.03 and 0.002, respectively). In addition, IRF7 and TLR7 showed dramatic downregulation (6 and 8 folds, respectively) in F2-F4 patients when compared to F0-F1 ones. qRT-PCR confirmed the altered expression patterns of TLR7 and MyD88 in F2-F4 patients when compared to either controls or F0-F1 patients. However, by qRT-PCR, IRF7 and NF-κB1 (TLR7 pathway transcription factors) exhibited similar mRNA abundance among F2-F4 and F0-F1 patients. These results suggest that TLR7 and MyD88 are possible candidates as biomarkers for the progression of HCV-induced liver fibrosis and/ or targets for therapeutic intervention. PMID:27135246

  3. Transcriptional Dysregulation of Upstream Signaling of IFN Pathway in Chronic HCV Type 4 Induced Liver Fibrosis

    PubMed Central

    Ibrahim, Marwa K.; Salum, Ghada Maher; Bader El Din, Noha G.; Dawood, Reham M.; Barakat, Ahmed; Khairy, Ahmed; El Awady, Mostafa K.

    2016-01-01

    IFN orchestrates the expression of various genes to halt hepatitis C virus (HCV) replication with the possibility of either reduced or increased liver fibrosis; due to controlled viral replication or overproduction of inflammatory mediators, repectively. In this study, we examined the transcriptional profiling of type I IFN related genes in HCV-chronically infected patients with varying degrees of liver fibrosis. PCR array was used to examine the expression of 84 type I IFN related genes in peripheral blood mononuclear cells (PBMCs) RNA from 12 treatment-naïve chronic HCV patients (5 F0-F1 and 7 F2-F4) and 5 healthy subjects. We further validated our results by quantitative real time PCR (qRT-PCR) in 103 treatment-naïve chronic HCV patients (43 F0-F1 and 60 F2-F4) and 15 controls. PCR array data revealed dysregulation in TLR7 pathway. The expression of TLR7 was decreased by 4 folds and MyD88 was increased by 3 folds in PBMCs of F2-F4 patients when compared to the healthy volunteers (p = 0.03 and 0.002, respectively). In addition, IRF7 and TLR7 showed dramatic downregulation (6 and 8 folds, respectively) in F2-F4 patients when compared to F0-F1 ones. qRT-PCR confirmed the altered expression patterns of TLR7 and MyD88 in F2-F4 patients when compared to either controls or F0-F1 patients. However, by qRT-PCR, IRF7 and NF-κB1 (TLR7 pathway transcription factors) exhibited similar mRNA abundance among F2-F4 and F0-F1 patients. These results suggest that TLR7 and MyD88 are possible candidates as biomarkers for the progression of HCV-induced liver fibrosis and/ or targets for therapeutic intervention. PMID:27135246

  4. Gamma interferon (IFN-γ) receptor restricts systemic dengue virus replication and prevents paralysis in IFN-α/β receptor-deficient mice.

    PubMed

    Prestwood, Tyler R; Morar, Malika M; Zellweger, Raphaël M; Miller, Robyn; May, Monica M; Yauch, Lauren E; Lada, Steven M; Shresta, Sujan

    2012-12-01

    We previously reported that mice lacking alpha/beta and gamma interferon receptors (IFN-α/βR and -γR) uniformly exhibit paralysis following infection with the dengue virus (DENV) clinical isolate PL046, while only a subset of mice lacking the IFN-γR alone and virtually no mice lacking the IFN-α/βR alone develop paralysis. Here, using a mouse-passaged variant of PL046, strain S221, we show that in the absence of the IFN-α/βR, signaling through the IFN-γR confers approximately 140-fold greater resistance against systemic vascular leakage-associated dengue disease and virtually complete protection from dengue-induced paralysis. Viral replication in the spleen was assessed by immunohistochemistry and flow cytometry, which revealed a reduction in the number of infected cells due to IFN-γR signaling by 2 days after infection, coincident with elevated levels of IFN-γ in the spleen and serum. By 4 days after infection, IFN-γR signaling was found to restrict DENV replication systemically. Clearance of DENV, on the other hand, occurred in the absence of IFN-γR, except in the central nervous system (CNS) (brain and spinal cord), where clearance relied on IFN-γ from CD8(+) T cells. These results demonstrate the roles of IFN-γR signaling in protection from initial systemic and subsequent CNS disease following DENV infection and demonstrate the importance of CD8(+) T cells in preventing DENV-induced CNS disease. PMID:22973027

  5. The chicken TH1 response: potential therapeutic applications of ChIFN-γ.

    PubMed

    Guo, Pengju; Thomas, Jesse D; Bruce, Matthew P; Hinton, Tracey M; Bean, Andrew G D; Lowenthal, John W

    2013-11-01

    The outcomes of viral infections are costly in terms of human and animal health and welfare worldwide. The observed increase in the virulence of some viruses and failure of many vaccines to stop these infections has lead to the apparent need to develop new anti-viral strategies. One approach to dealing with viral infection may be to employ the therapeutic administration of recombinant cytokines to act as 'immune boosters' to assist in augmenting the host response to virus. With this in mind, a greater understanding of the immune response, particularly cell mediated T-helper-1 (TH1) type responses, is imperative to the development of new anti-viral and vaccination strategies. Following the release of the chicken genome, a number of TH1-type cytokines have been identified, including chicken interleukin-12 (ChIL-12), ChIL-18 and interferon-γ ChIFN-γ), highlighting the nature of the TH1-type response in this non-mammalian vertebrate. To date a detailed analysis of the in vivo biological function of these cytokines has been somewhat hampered by access to large scale production techniques. This review describes the role of TH-1 cytokines in immune responses to viruses and explores their potential use in enhancing anti-viral treatment strategies in chickens. Furthermore, this review focuses on the example of ChIFN-γ treatment of Chicken Anemia Virus (CAV) infection. CAV causes amongst other things thymocyte depletion and thymus atrophy, as well as immunosuppression in chickens. However, due to vaccination, clinical disease appears less often, nevertheless, the subclinical form of the disease is often associated with secondary complicating infections due to an immunocompromised state. Since CAV-induced immunosuppression can cause a marked decrease in the immune response against other pathogens, understanding this aspect of the disease is critically important, as well as providing insights into developing new control approaches. With increasing emphasis on developing

  6. IFN-γ deficiency attenuates hepatic inflammation and fibrosis in a steatohepatitis model induced by a methionine- and choline-deficient high-fat diet.

    PubMed

    Luo, Xiao-Yu; Takahara, Terumi; Kawai, Kengo; Fujino, Masayuki; Sugiyama, Toshiro; Tsuneyama, Koichi; Tsukada, Kazuhiro; Nakae, Susumu; Zhong, Liang; Li, Xiao-Kang

    2013-12-01

    Cytokines play important roles in all stages of steatohepatitis, including hepatocyte injury, the inflammatory response, and the altered function of sinusoidal cells. This study examined the involvement of a major inflammatory cytokine, interferon-γ (IFN-γ), in the progression of steatohepatitis. In a steatohepatitis model by feeding a methionine- and choline-deficient high-fat (MCDHF) diet to both wild-type and IFN-γ-deficient mice, the liver histology, expression of genes encoding inflammatory cytokines, and fibrosis-related markers were examined. To analyze the effects of IFN-γ on Kupffer cells in vitro, we examined the tumor necrosis factor-α (TNF-α) production by a mouse macrophage cell line. Forty two days of MCDHF diet resulted in weight loss, elevated aminotransferases, liver steatosis, and inflammation in wild-type mice. However, the IFN-γ-deficient mice exhibited less extensive changes. RT-PCR revealed that the expression of tumor necrosis factor-α (TNF-α), transforming growth factor-β, inducible nitric oxide synthase, interleukin-4 and osteopontin were increased in wild-type mice, although they were suppressed in IFN-γ-deficient mice. Seventy days of MCDHF diet induced much more liver fibrosis in wild-type mice than in IFN-γ-deficient mice. The expression levels of fibrosis-related genes, α-smooth muscle actin, type I collagen, tissue inhibitor of matrix metalloproteinase-1, and matrix metalloproteinase-2, were dramatically increased in wild-type mice, whereas they were significantly suppressed in IFN-γ-deficient mice. Moreover, in vitro experiments showed that, when RAW 264.7 macrophages were treated with IFN-γ, they produced TNF-α in a dose-dependent manner. The present study showed that IFN-γ deficiency might inhibit the inflammatory response of macrophages cells and subsequently suppress stellate cell activation and liver fibrosis. These findings highlight the critical role of IFN-γ in the progression of steatohepatitis. PMID

  7. IFN-{gamma} gene expression in pancreatic islet-infiltrating mononuclear cells correlates with autoimmune diabetes in nonobese diabetic mice

    SciTech Connect

    Rabinovitch, A.; Suarez-Pinzon, W.L.; Sorensen, O.

    1995-05-01

    Insulin-dependent diabetes mellitus in nonobese diabetic (NOD) mice results from selective destruction of pancreatic islet {beta}-cells following islet filtration by mononuclear leukocytes. Cytokines produced by islet-infiltrating mononuclear cells may be involved in {beta}-cell destruction. Therefore, we analyzed cytokine mRNA expression, by reverse-transcriptase PCR (RT-PCR) assay, in mononuclear leukocytes isolated from pancreatic islets of four groups of mice: diabetes-prone female NOD mice; female NOD mice protected from diabetes by injection of CFA at an early age; male NOD mice with a low diabetes incidence; and female BALB/c mice that do not develop diabetes. We found that mRNA levels of IL-1{beta}, IL-2, IL-4, IL-10, and IFN-{gamma} in mononuclear cells from islets of diabetes-prone female NOD mice increased progressively as these cells infiltrated the islets from age 5 wk to diabetes onset (>13 wk). However, only IFN-{gamma} mRNA levels were significantly higher in islet mononuclear cells from 12-wk-old diabetes-prone female NOD mice than from less diabetes-prone NOD mice (CFA-treated females, and males) and normal mice (BALB/c). In contrast, IL-4 mRNA levels were lower in islet mononuclear cells from diabetes-prone female NOD mice than from NOD mice with low diabetes incidence (CFA-treated females and males). Splenic cell mRNA levels of IFN-{gamma} and IL-4 were not different in the four groups of mice. These results suggest that islet {beta}-cell destruction and diabetes in female NOD mice are dependent upon intra-islet IFN-{gamma} production by mononuclear cells, and that CFA-treated female NOD mice and male NOD mice may be protected from diabetes development by down-regulation of IFN-{gamma} production in the islets. 56 refs., 4 figs., 3 tabs.

  8. MicroRNA-155-IFN-γ Feedback Loop in CD4+T Cells of Erosive type Oral Lichen Planus

    PubMed Central

    Hu, Jing-Yu; Zhang, Jing; Ma, Jing-Zhi; Liang, Xue-Yi; Chen, Guan-Ying; Lu, Rui; Du, Ge-Fei; Zhou, Gang

    2015-01-01

    Oral lichen planus (OLP) is a T cell-mediated immune disorder, and we have indicated a Th1-dominated immune response in OLP. MicroRNA-155 (miR-155) could promote Th1 cells polarization. The present study aims to determine the role of miR-155 in immune response of OLP. The expression of miR-155 and the target mRNA was tested by Real-Time PCR. The serum levels of IL-2, 4, 10 and IFN-γ were examined with ELISA. Furthermore, in vitro study was built to observe the function of miR-155 in erosive-type OLP (EOLP). Finally, we determined the expression and correlation of miR-155 and SOCS1 in EOLP CD4+ T cells. The results showed miR-155 was high related with the disease severities. Besides, serum IFN-γ was specifically increased in EOLP group, while IL-4 was decreased. In vitro studies showed miR-155 could reinforce IFN-γ signal transducer, and the induction of IFN-γ could also promote miR-155 expression in EOLP CD4+ T cells. In addition, miR-155 levels were negatively related with SOCS1 mRNA expression in EOLP CD4+ T cells. Our study revealed a positive miR-155- IFN-γ feedback loop in EOLP CD4+ T cell, which might contribute to the Th1-dominated immune response. Furthermore, miR-155 could be used for the evaluation and treatment of OLP. PMID:26594049

  9. IFN-α subtypes: distinct biological activities in anti-viral therapy

    PubMed Central

    Gibbert, K; Schlaak, JF; Yang, D; Dittmer, U

    2013-01-01

    During most viral infections, the immediate host response is characterized by an induction of type I IFN. These cytokines have various biological activities, including anti-viral, anti-proliferative and immunomodulatory effects. After induction, they bind to their IFN-α/β receptor, which leads to downstream signalling resulting in the expression of numerous different IFN-stimulated genes. These genes encode anti-viral proteins that directly inhibit viral replication as well as modulate immune function. Thus, the induction of type I IFN is a very powerful tool for the host to fight virus infections. Many viruses evade this response by various strategies like the direct suppression of IFN induction or inhibition of the IFN signalling pathway. Therefore, the therapeutic application of exogenous type I IFN or molecules that induce strong IFN responses should be of great potential for future immunotherapies against viral infections. Type I IFN is currently used as a treatment in chronic hepatitis B and C virus infection, but as yet is not widely utilized for other viral infections. One reason for this restricted clinical use is that type I IFN belongs to a multigene family that includes 13 different IFN-α subtypes and IFN-β, whose individual anti-viral and immunomodulatory properties have so far not been investigated in detail to improve IFN therapy against viral infections in humans. In this review, we summarize the recent achievements in defining the distinct biological functions of type I IFN subtypes in cell culture and in animal models of viral infection as well as their clinical usage in chronic hepatitis virus infections. PMID:23072338

  10. HCV infection selectively impairs type I but not type III IFN signaling.

    PubMed

    Chandra, Partha K; Bao, Lili; Song, Kyoungsub; Aboulnasr, Fatma M; Baker, Darren P; Shores, Nathan; Wimley, William C; Liu, Shuanghu; Hagedorn, Curt H; Fuchs, Serge Y; Wu, Tong; Balart, Luis A; Dash, Srikanta

    2014-01-01

    A stable and persistent Hepatitis C virus (HCV) replication cell culture model was developed to examine clearance of viral replication during long-term treatment using interferon-α (IFN-α), IFN-λ, and ribavirin (RBV). Persistently HCV-infected cell culture exhibited an impaired antiviral response to IFN-α+RBV combination treatment, whereas IFN-λ treatment produced a strong and sustained antiviral response that cleared HCV replication. HCV replication in persistently infected cells induced chronic endoplasmic reticulum (ER) stress and an autophagy response that selectively down-regulated the functional IFN-α receptor-1 chain of type I, but not type II (IFN-γ) or type III (IFN-λ) IFN receptors. Down-regulation of IFN-α receptor-1 resulted in defective JAK-STAT signaling, impaired STAT phosphorylation, and impaired nuclear translocation of STAT. Furthermore, HCV replication impaired RBV uptake, because of reduced expression of the nucleoside transporters ENT1 and CNT1. Silencing ER stress and the autophagy response using chemical inhibitors or siRNA additively inhibited HCV replication and induced viral clearance by the IFN-α+RBV combination treatment. These results indicate that HCV induces ER stress and that the autophagy response selectively impairs type I (but not type III) IFN signaling, which explains why IFN-λ (but not IFN-α) produced a sustained antiviral response against HCV. The results also indicate that inhibition of ER stress and of the autophagy response overcomes IFN-α+RBV resistance mechanisms associated with HCV infection. PMID:24215913

  11. HCV Infection Selectively Impairs Type I but Not Type III IFN Signaling

    PubMed Central

    Chandra, Partha K.; Bao, Lili; Song, Kyoungsub; Aboulnasr, Fatma M.; Baker, Darren P.; Shores, Nathan; Wimley, William C.; Liu, Shuanghu; Hagedorn, Curt H.; Fuchs, Serge Y.; Wu, Tong; Balart, Luis A.; Dash, Srikanta

    2015-01-01

    A stable and persistent Hepatitis C virus (HCV) replication cell culture model was developed to examine clearance of viral replication during long-term treatment using interferon-α (IFN-α), IFN-λ, and ribavirin (RBV). Persistently HCV-infected cell culture exhibited an impaired antiviral response to IFN-α+RBV combination treatment, whereas IFN-λ treatment produced a strong and sustained antiviral response that cleared HCV replication. HCV replication in persistently infected cells induced chronic endoplasmic reticulum (ER) stress and an autophagy response that selectively down-regulated the functional IFN-α receptor-1 chain of type I, but not type II (IFN-γ) or type III (IFN-λ) IFN receptors. Down-regulation of IFN-α receptor-1 resulted in defective JAK–STAT signaling, impaired STAT phosphorylation, and impaired nuclear translocation of STAT. Furthermore, HCV replication impaired RBV uptake, because of reduced expression of the nucleoside transporters ENT1 and CNT1. Silencing ER stress and the autophagy response using chemical inhibitors or siRNA additively inhibited HCV replication and induced viral clearance by the IFN-α+RBV combination treatment. These results indicate that HCV induces ER stress and that the autophagy response selectively impairs type I (but not type III) IFN signaling, which explains why IFN-λ (but not IFN-α) produced a sustained antiviral response against HCV. The results also indicate that inhibition of ER stress and of the autophagy response overcomes IFN-α+RBV resistance mechanisms associated with HCV infection. PMID:24215913

  12. A RIG-I 2CARD-MAVS200 CHIMERIC PROTEIN RECONSTITUTES IFN-B INDUCTION AND ANTIVIRAL RESPONSE IN MODELS DEFICIENT IN TYPE I IFN RESPONSE

    PubMed Central

    Nistal-Villán, Estanislao; Rodríguez-García, Estefanía; Di Scala, Marianna; Ferrero-Laborda, Roberto; Olagüe, Cristina; Vales, África; Carte-Abad, Beatriz; Crespo, Irene; García-Sastre, Adolfo; Prieto, Jesús; Larrea, Esther; González-Aseguinolaza, Gloria

    2015-01-01

    RIG-I like receptors (RLRs) are cellular sensor proteins that detect certain RNA species produced during viral infections. RLRs activate a signaling cascade that results in the production of interferon-beta (IFN-β) as well as several other cytokines with antiviral and proinflammatory activities. We explored the potential of different constructs based on RLRs to induce the IFN-β pathway and create an antiviral state in type I IFN-unresponsive models. A chimeric construct composed of RIG-I 2CARD and the first 200 amino acids of MAVS (2CARD-MAVS200) showed an enhanced ability to induce IFN-β as compared to other stimulatory constructs. Furthermore, this human chimeric construct showed a superior ability to activate IFN-β expression in cells from various species. This construct was found to overcome the restrictions of blocking IFN-β induction or signaling by a number of viral antagonist proteins. Additionally, the antiviral activity of this chimera was demonstrated in influenza virus and HBV infection mouse models using adeno-associated viral (AAV) vectors as a delivery vehicle. We propose that AAV vectors expressing 2CARD-MAVS200 chimeric protein can reconstitute IFN-β induction and recover a partial antiviral state in different models that do not respond to recombinant IFN-β treatment. PMID:25966783

  13. Evaluation of gamma interferon (IFN-gamma)-induced protein 10 (IP-10) responses for detection of cattle infected with Mycobacterium bovis: comparisons to IFN-gamma responses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gamma interferon (IFN-gamma)-induced protein 10 (IP-10) has recently shown promise as a diagnostic biomarker of Mycobacterium tuberculosis infection of humans. The aim of the current study was to compare IP-10 and IFN-gamma responses upon Mycobacterium bovis infection in cattle using archived sample...

  14. Induction of multiple programmed cell death pathways by IFN-beta in human non-small-cell lung cancer cell lines.

    PubMed

    Zhang, H; Koty, P P; Mayotte, J; Levitt, M L

    1999-02-25

    Tissue transglutaminase (tTG) and keratinocyte transglutaminase (kTG), as well as the cross-linked envelopes (CLE) that they form, have been associated with squamous differentiation and programmed cell death in epithelial cells. When interferon-beta (IFN-beta) was used to stimulate differentiation and programmed cell death in the human lung cancer cell lines NCI-H596 and NCI-H226, the cells underwent a decrease in cellular density. In NCI-H596 IFN-beta caused an increase in kTG activity and DNA fragmentation in the lower density cells, which were significantly slower growing than control cells. However, in the higher density cells, which were only slightly slower growing than control cells, IFN-beta caused an increase in tTG activity and CLE competence. Dual-parameter flow cytometry demonstrated that IFN-beta-induced squamous differentiation preceded programmed cell death. Treatment of NCI-H596 cells with monodansylcadaverine, a transglutaminase inhibitor, prevented the increase in CLE competence, but did not inhibit DNA fragmentation. These results suggest that IFN-beta can induce NCI-H596 cells to enter multiple cell death pathways and that these pathways are not only differentiation related, but may also be growth driven. PMID:10047455

  15. Long Non-Coding RNA BST2/BISPR is Induced by IFN and Regulates the Expression of the Antiviral Factor Tetherin

    PubMed Central

    Barriocanal, Marina; Carnero, Elena; Segura, Victor; Fortes, Puri

    2015-01-01

    Many long non-coding RNAs (lncRNAs) are expressed in cells but only a few have been well characterized. In these cases, lncRNAs have been shown to be key regulators of several cellular processes. Therefore, there is a great need to understand the function of more lncRNAs and their regulation in response to stimuli. Interferon (IFN) is a key molecule in the cellular antiviral response. IFN binding to its receptor activates transcription of several IFN-stimulated genes (ISGs) that function as potent antivirals. In addition, several ISGs are positive or negative regulators of the IFN pathway. This is essential to ensure a strong antiviral response and a later return of the cell to homeostasis. As the ISGs described to date are coding genes, we sought to determine whether IFN also regulates the expression of long non-coding ISGs. To this aim, we used RNA sequencing to analyze the transcriptome of control and HuH7 cells treated with IFNα2. The results show that IFN-treatment regulates the expression of several unknown non-coding transcripts. We have validated two lncRNAs upregulated after treatment with different doses of type I IFNα2 in different cells or with type III IFNλ. These lncRNAs were also induced by influenza and vesicular stomatitis virus mutants unable to block the IFN response, but not by several wild-type lytic viruses tested. These lncRNA genes were named lncISG15 and lncBST2 as they are located close to ISGs ISG15 and BST2, respectively. Interestingly, inhibition experiments showed that lncBST2 is a positive regulator of BST2. Therefore lncBST2 has been renamed BISPR, from BST2 IFN-stimulated positive regulator. Our results may have therapeutic implications as lncBST2/BISPR, but also lncISG15 and their coding neighbors, are increased in cells infected with hepatitis C virus and in the liver of infected patients. These results allow us to hypothesize that several lncRNAs could be activated by IFN to control the potency of the antiviral IFN response

  16. IFN-τ inhibits S. aureus-induced inflammation by suppressing the activation of NF-κB and MAPKs in RAW 264.7 cells and mice with pneumonia.

    PubMed

    Zhao, Gan; Wu, Haichong; Jiang, Kangfeng; Rui, Guangze; Zhu, Zhe; Qiu, Changwei; Guo, Mengyao; Deng, Ganzhen

    2016-06-01

    Staphylococcus aureus (S. aureus), a significant cause of pneumonia, leads to severe inflammation. Few effective treatments or drugs have been reported for S. aureus infection. Interferon tau (IFN-τ) is a type I interferon with low cellular toxicity even at high doses. Previous studies have reported that IFN-τ could significantly mitigate tissue inflammation; however, IFN-τ treatment in S. aureus-induced pneumonia has not been well reported. Thus, the aim of this study was to identify the anti-inflammatory mechanism of IFN-τ in S. aureus-induced pneumonia in mice. A S. aureus-induced pneumonia model and RAW 264.7 cells were used in this research. The histopathological as well as lung wet to dry ratio (W/D) and myeloperoxidase (MPO) activity results showed that IFN-τ could protect the lung from S. aureus damage. In addition, ELISA and qPCR revealed that IFN-τ treatment led to a decreased expression of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) in both the cells and mouse model, but IL-10 was increased. TLR2, which is involved in the response during S. aureus infection, was also down-regulated by IFN-τ treatment and directly affected NF-κB and MAPK pathway activation. Then, we examined the phosphorylation of IκBα, NF-κB p65 and MAPKs by western blotting, and the results displayed that the phosphorylation of IκBα, NF-κB p65 and MAPKs was inhibited upon IFN-τ treatment in both the cells and mouse model. These findings indicate that IFN-τ has anti-inflammatory properties in vitro and in vivo through the inhibition of NF-κB and MAPK activation, suggesting that IFN-τ may have potential as a therapeutic agent against S. aureus-induced inflammatory diseases. PMID:27025553

  17. Interferon (IFN) production by peripheral blood mononuclear (PBM) cells of an elderly population

    SciTech Connect

    Nelson, B.J.; Murasko, D.M.

    1986-03-05

    Previous investigations in the laboratory have reported decreased mitogen responses of PBM's from elderly individuals compared to responses of young adults to PHA and ConA. Current studies have investigated the role of IFN in this decreased T cell responsiveness of the elderly. Supernatants of PBM's from 80 elderly (mean age 85) and 50 young individuals (mean age 28) were assayed for antiviral activity, after incubation with optimum and supraoptimum concentrations of mitogen for 24-120 hrs. IFN levels were maximum for both elderly and young populations at 72 hrs coinciding with time of maximum proliferation as determined by uptake of /sup 3/H thymidine. IFN levels declined with longer incubation periods. All IFN produced was IFN-gamma as determined by sensitivity to pH 2 and by neutralizations with monoclonal antibody specific for human IFN-gamma and polyclonal antiserum specific for IFN-alpha. The elderly population's mean IFN titers for both PHA and ConA were about 39% of the mean titers of the young (p less than or equal to 0.02). Both elderly and young groups displayed significant positive correlation between the amount of IFN produced and the level of proliferation in response to the mitogens (p less than or equal to 0.036). Therefore, the above data suggests the decreased levels of IFN produced by elderly PBM's may be one of the factors responsible for the observed decreased proliferative response to mitogens.

  18. Effects of parturition and dexamethasone on DNA methylation patterns of IFN-γ and IL-4 promoters in CD4+ T-lymphocytes of Holstein dairy cows

    PubMed Central

    Paibomesai, Marlene; Hussey, Brendan; Nino-Soto, Maria; Mallard, Bonnie A.

    2013-01-01

    This study investigated epigenetic mechanisms by which DNA methylation affects the function of bovine adaptive immune system cells, particularly during the peripartum period, when shifts in type 1 and type 2 immune response (IR) biases are thought to occur. Stimulation of CD4+ T-lymphocytes isolated from 5 Holstein dairy cows before and after parturition with concanavalin A (ConA) and stimulation of CD4+ T-lymphocytes isolated from 3 Holstein dairy cows in mid-lactation with ConA alone or ConA plus dexamethasone (Dex) had significant effects on production of the cytokines interferon gamma (IFN-γ, type 1) and interleukin 4 (IL-4, type 2) that were consistent with DNA methylation profiles of the IFN-γ gene promoter region but not consistent for the IL-4 promoter region. ConA stimulation increased the production of both cytokines before and after parturition. It decreased DNA methylation in the IFN-γ promoter region but increased for IL-4 promoter region. Parturition was associated with an increase in IFN-γ production in ConA-stimulated cells that approached significance. Overall, DNA methylation in both promoter regions increased between the prepartum and postpartum periods, although this did not correlate with secreted cytokine concentrations. Dexamethasone treated cells acted in a manner consistent with the glucocorticoid’s immunosuppressive activity, which mimicked the change at the IFN-γ promoter region observed during parturition. These results support pregnancy as type 2 IR biased, with increases of IFN-γ occurring after parturition and an increase in IL-4 production before calving. It is likely that these changes may be epigenetically controlled. PMID:23814356

  19. IFN-β Therapy Regulates TLR7-Mediated Response in Plasmacytoid Dendritic Cells of Multiple Sclerosis Patients Influencing an Anti-Inflammatory Status.

    PubMed

    Severa, Martina; Rizzo, Fabiana; Giacomini, Elena; Annibali, Viviana; Gafa, Valerie; Romano, Silvia; Buscarinu, Maria Chiara; Fornasiero, Arianna; Salvetti, Marco; Coccia, Eliana Marina

    2015-09-01

    Plasmacytoid dendritic cells (pDCs) display altered immune-phenotype in multiple sclerosis (MS) patients and are found actively recruited in postmortem MS brain lesions, implying that their immune regulation may represent an important aspect of MS pathogenesis. Because of the reported Toll-like receptor 7 (TLR7) implication in autoimmunity, in this study we characterized how IFN-β therapy impacts on pDC activation to TLR7 triggering in MS patients, aspect only poorly investigated so far. In vivo IFN-β administration regulates pDC functions in TLR7-treated peripheral blood mononuclear cell (PBMC) cultures differently from what is observed in isolated cells, suggesting that IFN-β may activate inhibitory mechanisms in MS peripheral blood involved in turning off pDC response to dampen the ongoing inflammation. Indeed, IL-10, a key regulatory cytokine found increased upon TLR7 stimulation in in vivo IFN-β-exposed PBMCs, directly reduced pDC-mediated IFN-α production. IFN-β therapy also shaped T-cell responses by decreasing TLR7-induced pDC maturation and inducing T-cell inhibitory molecules. Accordingly, raised pDC-induced IL-27 and decreased IL-23 expression, together with high IL-10 level, contribute to inhibit Th17 cell differentiation. Our study uncovered a role for IFN-β in the regulation of TLR7-mediated pDC responses in MS toward an anti-inflammatory phenotype opening new opportunities to better understand mechanisms of action of this drug in controlling MS immunopathogenesis. PMID:25923141

  20. Astragalus Root and Elderberry Fruit Extracts Enhance the IFN-β Stimulatory Effects of Lactobacillus acidophilus in Murine-Derived Dendritic Cells

    PubMed Central

    Frøkiær, Hanne; Henningsen, Louise; Metzdorff, Stine Broeng; Weiss, Gudrun; Roller, Marc; Flanagan, John; Fromentin, Emilie; Ibarra, Alvin

    2012-01-01

    Many foods and food components boost the immune system, but little data are available regarding the mechanisms by which they do. Bacterial strains have disparate effects in stimulating the immune system. Indendritic cells, the gram-negative bacteria Escherichia coli upregulates proinflammatory cytokines, whereas gram-positive Lactobacillus acidophilus induces a robust interferon (IFN)-β response. The immune-modulating effects of astragalus root and elderberry fruit extracts were examined in bone marrow-derived murine dendritic cells that were stimulated with L. acidophilus or E. coli. IFN-β and other cytokines were measured by ELISA and RT-PCR. Endocytosis of fluorescence-labeled dextran and L. acidophilus in the presence of elderberry fruit or astragalus root extract was evaluated in dendritic cells. Our results show that both extracts enhanced L. acidophilus-induced IFN-β production and slightly decreased the proinflammatory response to E. coli. The enhanced IFN-β production was associated with upregulation of toll-like receptor 3 and to a varying degree, the cytokines IL-12, IL-6, IL-1β and TNF-α. Both extracts increased endocytosis in immature dendritic cells, and only slightly influenced the viability of the cells. In conclusion, astragalus root and elderberry fruit extracts increase the IFN-β inducing activity of L. acidophilus in dendritic cells, suggesting that they may exert antiviral and immune-enhancing activity. PMID:23118903

  1. IFN-γ release assays in the diagnosis of latent tuberculosis infection among immunocompromised adults.

    PubMed

    Redelman-Sidi, Gil; Sepkowitz, Kent A

    2013-08-15

    Immunocompromised persons with latent tuberculosis infection (LTBI) are at increased risk for tuberculosis reactivation compared with the general population. The tuberculin skin test, the traditional assay for diagnosing LTBI, has reduced accuracy in immunocompromised patients. IFN-γ release assays (IGRAs) are in vitro blood tests that measure T-cell release of IFN-γ after stimulation with antigens unique to Mycobacterium tuberculosis. Here we review the data for the use of QuantiFERON-TB Gold In-Tube and T-SPOT.TB, the two currently available IGRAs, in immunocompromised adults, including persons infected with HIV, patients with immune-mediated inflammatory disorders, candidates for treatment with tumor necrosis factor-α inhibitors, patients receiving hemodialysis, solid-organ transplant recipients, and patients with cancer. On the basis of the available data, IGRAs have advantages over the tuberculin skin test in specific patient populations and in certain situations. Further studies are needed to more accurately define the usefulness of IGRAs in immunocompromised patients. PMID:23262514

  2. FAT10 Is Critical in Influenza A Virus Replication by Inhibiting Type I IFN.

    PubMed

    Zhang, Yanli; Tang, Jun; Yang, Ning; Liu, Qiang; Zhang, Qingchao; Zhang, Yanxu; Li, Ning; Zhao, Yan; Li, Shunwang; Liu, Song; Zhou, Huandi; Li, Xiao; Tian, Mingyao; Deng, Jiejie; Xie, Peng; Sun, Yang; Lu, Huijun; Zhang, Michael Q; Jin, Ningyi; Jiang, Chengyu

    2016-08-01

    The H5N1 avian influenza virus causes severe disease and high mortality, making it a major public health concern worldwide. The virus uses the host cellular machinery for several steps of its life cycle. In this report, we observed overexpression of the ubiquitin-like protein FAT10 following live H5N1 virus infection in BALB/c mice and in the human respiratory epithelial cell lines A549 and BEAS-2B. Further experiments demonstrated that FAT10 increased H5N1 virus replication and decreased the viability of infected cells. Total RNA extracted from H5N1 virus-infected cells, but not other H5N1 viral components, upregulated FAT10, and this process was mediated by the retinoic acid-induced protein I-NF-κB signaling pathway. FAT10 knockdown in A549 cells upregulated type I IFN mRNA expression and enhanced STAT1 phosphorylation during live H5N1 virus infection. Taken together, our data suggest that FAT10 was upregulated via retinoic acid-induced protein I and NF-κB during H5N1 avian influenza virus infection. And the upregulated FAT10 promoted H5N1 viral replication by inhibiting type I IFN. PMID:27354218

  3. Yeast extract promotes decolorization of azo dyes by stimulating azoreductase activity in Shewanella sp. strain IFN4.

    PubMed

    Imran, Muhammad; Arshad, Muhammad; Negm, Fayek; Khalid, Azeem; Shaharoona, Baby; Hussain, Sabir; Mahmood Nadeem, Sajid; Crowley, David E

    2016-02-01

    Biological treatment of azo dyes commonly requires a combined anaerobic-aerobic process in which initial decolorization is achieved by reductive cleavage of azo bonds on the parent molecule. The present study was conducted to examine the relative importance of co-substrates for driving reductive decolorization of azo dyes by Shewanella sp. strain IFN4 using whole cells and enzyme assays. Results showed that the dye decolorization by strain IFN4 was faster in medium containing 1gL(-1) yeast extract (YE) as compared to nine other co-substrates. Moreover, only YE stimulated azoreductase activity (increased from 1.32 to 4.19U/mg protein). Increasing the level of YE up to 8gL(-)(1) resulted into 81% decolorization of the dye in 1h along with an increase in azoreductase activity up to 6.16U/mg protein. Among the components of YE, only riboflavin stimulated the decolorization process as well as enzyme activity. Moreover, strain IFN4 demonstrated flavin reductase activity, and a significant correlation (r(2)=0.98) between flavin reduction and dye reduction by this strain emphasized the involvement of flavin compounds in the decolorization process. The results of this study show that YE serves both as a source of reducing equivalents and an electron shuttle for catalyzing dye reduction. PMID:26454074

  4. Growing tumors induce a local STING dependent Type I IFN response in dendritic cells.

    PubMed

    Andzinski, Lisa; Spanier, Julia; Kasnitz, Nadine; Kröger, Andrea; Jin, Lei; Brinkmann, Melanie M; Kalinke, Ulrich; Weiss, Siegfried; Jablonska, Jadwiga; Lienenklaus, Stefan

    2016-09-15

    The importance of endogenous Type I IFNs in cancer immune surveillance is well established by now. Their role in polarization of tumor-associated neutrophilic granulocytes into anti-tumor effector cells has been recently demonstrated. Yet, the cellular source of Type I IFNs as well as the mode of induction is not clearly defined. Here, we demonstrate that IFN-β is induced by growing murine tumors. Induction is mainly mediated via STING-dependent signaling pathways, suggesting tumor derived DNA as trigger. Transcription factors IRF3 and IRF5 were activated under these conditions which is consistent with tumor infiltrating dendritic cells (DCs) being the major cellular source of IFN-β at the tumor site. Besides DCs, tumor cells themselves are induced to contribute to the production of IFN-β. Taken together, our data provide further information on immune surveillance by Type I IFNs and suggest novel potent cellular targets for future cancer therapy. PMID:27116225

  5. Immunological response and overall survival in a subset of advanced renal cell carcinoma patients from a randomized phase 2/3 study of naptumomab estafenatox plus IFN-α versus IFN

    PubMed Central

    Elkord, Eyad; Burt, Deborah J.; Sundstedt, Anette; Nordle, Örjan; Hedlund, Gunnar; Hawkins, Robert E.

    2015-01-01

    Naptumomab estafenatox/ABR-217620/ANYARA (Nap) has been evaluated in clinical phase 1 and 2/3 studies. RCC patients in the phase 2/3 trial were randomized 1:1 in an open label study to receive Nap+IFN-α or IFN-α. In this study, we analyzed the UK patients for their immunological response in relation to prolonged overall survival (OS). We found that Nap-specific T cells were reduced after 3 treatment days in patients' peripheral blood. Levels of both Nap-specific CD4+ and CD8+ T cells were significantly higher 8 days after the first treatment. Patients with such pattern of reduction and expansion of Nap-binding T cells also showed increased levels of IL-2 and IFN-γ in plasma 3 hours after the first Nap treatment. In addition, Nap caused an increase of IL-6, IL-10 and TNF-α. The patients in the UK subset showed a tendency of OS benefit after Nap treatment. Most Nap treated patients with long OS had low baseline IL-6 and normal levels of anti-SEA/E-120 antibodies. Furthermore, patients with pronounced Nap induced IL-2 and T cell expansion had long OS. In conclusion, patients with low baseline IL-6 and normal anti-SEA/E-120 may respond well to Nap by T cell activation and expansion paving the way for anti-tumour effects. PMID:25669986

  6. Hepatitis B virus-specific T-cell responses during IFN administration in a small cohort of chronic hepatitis B patients under nucleos(t)ide analogue treatment.

    PubMed

    Sprinzl, M F; Russo, C; Kittner, J; Allgayer, S; Grambihler, A; Bartsch, B; Weinmann, A; Galle, P R; Schuchmann, M; Protzer, U; Bauer, T

    2014-01-01

    The effect of pegylated interferon-α (IFN) add-on therapy on HBV-specific T-cell responses was evaluated in 12 patients with stable, undetectable hepatitis B virus (HBV) load under nucleos(t)ide analogue therapy. Peripheral blood mononuclear cells were isolated at week 0, 4, 8, 12, 24 and 48 of IFN add-on therapy. Quantity and quality of circulating HBV S- and core-specific CD4 and CD8 T cells were analysed ex vivo by flow cytometry. HBV S- and core-specific CD4 T-cell numbers modestly increased within 8 weeks of IFN administration (P = 0.0391 and P = 0.0195), whereas HBV-specific CD8 T cells in general showed only minor changes under IFN add-on therapy. Functionality of HBV-specific CD4 but not CD8 T cells positively correlated with serum transaminase activity. In addition, we observed an increase in CD4 T cells producing tumour necrosis factor-α (TNFα) without antigen restimulation (P = 0.0039), which correlated with elevated transaminases. During IFN add-on therapy, two patients developed an anti-HBs seroconversion, only one of whom showed a relevant increase in HBV-specific T cells. In conclusion, IFN add-on therapy of chronic hepatitis B increased HBV-specific T-cell responses and affected a previously unrecognized TNFα-monofunctional CD4 T-cell population. Although the observed T-cell responses did not correlate with HBsAg seroconversion, we expect additional insights into the immunopathogenesis of hepatitis B, following the characterization of the newly identified TNF α-monofunctional T-cell population. PMID:24251783

  7. Lymphocytes and not IFN-gamma mediate expression of iNOS by intestinal epithelium in murine cryptosporidiosis.

    PubMed

    Nordone, Shila K; Gookin, Jody L

    2010-05-01

    We hypothesized that unrecognized differences in epithelial expression of inducible nitric oxide synthase (iNOS), resulting from engineered immunodeficiency, could explain the contradictory findings of prior studies regarding the importance of nitric oxide (NO) in murine models of Cryptosporidium parvum infection. Severe combined immunodeficient mice (SCID) failed to constitutively or inducibly express epithelial iNOS or increase NO synthesis in response to C. parvum infection. In contrast, mice lacking IFN-gamma alone induced both epithelial iNOS expression and NO synthesis in response to infection. Accordingly, lymphocytes mediate epithelial expression of iNOS and NO synthesis independent of IFN-gamma in response to C. parvum infection. These findings in large part explain the contradictory conclusions of prior studies regarding the role of iNOS in C. parvum infection. PMID:20352449

  8. HCV-specific immune responses induced by CIGB-230 in combination with IFN-α plus ribavirin

    PubMed Central

    Amador-Cañizares, Yalena; Martínez-Donato, Gillian; Álvarez-Lajonchere, Liz; Vasallo, Claudia; Dausá, Mariacarla; Aguilar-Noriega, Daylen; Valenzuela, Carmen; Raíces, Ivette; Dubuisson, Jean; Wychowski, Czeslaw; Cinza-Estévez, Zurina; Castellanos, Marlén; Núñez, Magdalys; Armas, Anny; González, Yaimé; Revé, Ismariley; Guerra, Ivis; Pérez Aguiar, Ángel; Dueñas-Carrera, Santiago

    2014-01-01

    AIM: To analyze hepatitis C virus (HCV)-specific immune responses in chronically infected patients under triple therapy with interferon-α (IFN-α) plus ribavirin and CIGB-230. METHODS: CIGB-230 was administered in different schedules with respect to IFN-α plus ribavirin therapy. Paired serum and peripheral blood mononuclear cells (PBMC) samples from baseline and end of treatment were analyzed. The HCV-specific humoral response was tested by enzyme-linked immunosorbent assay, neutralizing antibodies were evaluated by cell culture HCV neutralization assays, PBMC proliferation was assayed by carboxyfluorescein succinimidyl ester staining and IFN-γ secretion was assessed by enzyme-linked immunospot. Data on virological and histological response and their association with immune variables are also provided. RESULTS: From week 12 to week 48, all groups of patients showed a significant reduction in mean leukocyte counts. Statistically significant reductions in antibody titers were frequent, but only individuals immunized with CIGB-230 as early add-on treatment sustained the core-IgG response, and the neutralizing antibody response was enhanced only in patients receiving CIGB-230. Cell-mediated immune responses also tended to decline, but significant reductions in IFN-γ secretion and total absence of core-specific lymphoproliferation were exclusive of the control group. Only CIGB-230-immunized individuals showed de novo induced lymphoproliferative responses against the structural antigens. Importantly, it was demonstrated that the quality of the CIGB-230-induced immune response depended on the number of doses and timing of administration in relation to the antiviral therapy. Specifically, the administration of 6 doses of CIGB-230 as late add-on to therapy increased the neutralizing antibody activity and the de novo core-specific IFN-γ secretion, both of which were associated with the sustained virological response. CONCLUSION: CIGB-230, combined with IFN

  9. Shp-2 contributes to anti-RSV activity in human pulmonary alveolar epithelial cells by interfering with the IFN-α-induced Jak/Stat1 pathway

    PubMed Central

    Wang, Saisai; Zheng, Gang; Zhao, Lifang; Xu, Feng; Qian, Jing

    2015-01-01

    Src homology phosphotyrosyl phosphatase 2 (Shp-2) is a ubiquitously expressed protein that is involved in a variety of cellular processes, including antiviral interferon signalling pathways. In this study, we investigated the role of Shp-2 in the host cell interactions of human respiratory syncytial virus (RSV). We report significant changes in the expression of Shp-2 in human pulmonary alveolar epithelial cells (A549) upon RSV infection. We also report that blocking Shp-2 does not affect viral replication or virus-induced interferon-alpha (IFN-α) production. Interestingly, whereas A549 cells were activated by IFN-α, the blocking of Shp-2 resulted in increased viral replication that was associated with the reduced expression of the IFN-stimulated genes of 2′,5′-oligoadenylate synthetases and Mx1, and the concomitant inhibition of Stat1 tyrosine phosphorylation. Our findings suggest that Shp-2 contributes to the control of RSV replication and progeny production in pulmonary alveolar epithelial cells by interfering with IFN-α-induced Jak/Stat1 pathway activation rather than by affecting the production of IFN-α itself. PMID:26119280

  10. Interdependent IL-7 and IFN-γ signalling in T-cell controls tumour eradication by combined α-CTLA-4+α-PD-1 therapy.

    PubMed

    Shi, Lewis Zhichang; Fu, Tihui; Guan, Baoxiang; Chen, Jianfeng; Blando, Jorge M; Allison, James P; Xiong, Liangwen; Subudhi, Sumit K; Gao, Jianjun; Sharma, Padmanee

    2016-01-01

    Combination therapy with α-CTLA-4 and α-PD-1 has shown significant clinical responses in different types of cancer. However, the underlying mechanisms remain elusive. Here, combining detailed analysis of human tumour samples with preclinical tumour models, we report that concomitant blockade of CTLA-4 and PD-1 improves anti-tumour immune responses and synergistically eradicates tumour. Mechanistically, combination therapy relies on the interdependence between IL-7 and IFN-γ signalling in T cells, as lack of either pathway abrogates the immune-boosting and therapeutic effects of combination therapy. Combination treatment increases IL-7Rα expression on tumour-infiltrating T cells in an IFN-γ/IFN-γR signalling-dependent manner, which may serve as a potential biomarker for clinical trials with immune checkpoint blockade. Our data suggest that combining immune checkpoint blockade with IL-7 signalling could be an effective modality to improve immunotherapeutic efficacy. Taken together, we conclude that combination therapy potently reverses immunosuppression and eradicates tumours via an intricate interplay between IFN-γ/IFN-γR and IL-7/IL-7R pathways. PMID:27498556

  11. Interdependent IL-7 and IFN-γ signalling in T-cell controls tumour eradication by combined α-CTLA-4+α-PD-1 therapy

    PubMed Central

    Shi, Lewis Zhichang; Fu, Tihui; Guan, Baoxiang; Chen, Jianfeng; Blando, Jorge M.; Allison, James P.; Xiong, Liangwen; Subudhi, Sumit K.; Gao, Jianjun; Sharma, Padmanee

    2016-01-01

    Combination therapy with α-CTLA-4 and α-PD-1 has shown significant clinical responses in different types of cancer. However, the underlying mechanisms remain elusive. Here, combining detailed analysis of human tumour samples with preclinical tumour models, we report that concomitant blockade of CTLA-4 and PD-1 improves anti-tumour immune responses and synergistically eradicates tumour. Mechanistically, combination therapy relies on the interdependence between IL-7 and IFN-γ signalling in T cells, as lack of either pathway abrogates the immune-boosting and therapeutic effects of combination therapy. Combination treatment increases IL-7Rα expression on tumour-infiltrating T cells in an IFN-γ/IFN-γR signalling-dependent manner, which may serve as a potential biomarker for clinical trials with immune checkpoint blockade. Our data suggest that combining immune checkpoint blockade with IL-7 signalling could be an effective modality to improve immunotherapeutic efficacy. Taken together, we conclude that combination therapy potently reverses immunosuppression and eradicates tumours via an intricate interplay between IFN-γ/IFN-γR and IL-7/IL-7R pathways. PMID:27498556

  12. Hepatitis B virus-induced calreticulin protein is involved in IFN resistance.

    PubMed

    Yue, Xin; Wang, Hui; Zhao, Fanpeng; Liu, Shi; Wu, Jianguo; Ren, Wendan; Zhu, Ying

    2012-07-01

    IFN-α is a widely used treatment for hepatitis B virus (HBV) infection, and IFN resistance caused by viral and/or host factors is currently a challenging clinical problem. A better understanding of the molecular mechanisms underlying IFN immunotherapy in the treatment of viral infection would be very beneficial clinically and is of immense clinical importance. Calreticulin (CRT) is an endoplasmic reticulum luminal calcium-binding chaperone that is involved in the regulation of calcium homoeostasis, the folding of newly synthesized proteins, and many other cellular functions. However, little is known about the role of CRT in HBV infection. In this study, we observed high levels of CRT expression in the sera and PBMCs of patients with HBV relative to those of healthy individuals. HBV upregulated the expression of CRT at the transcriptional level. Further investigation showed that HBV-induced CRT enhanced HBV replication by antagonizing the IFN pathway. CRT suppressed the production of endogenous IFN-α by reducing the nuclear translocation of IFN regulatory factor-7 but not IFN regulatory factor-3. Furthermore, CRT also suppressed the antiviral activity of IFN-α by inhibiting the phosphorylation of STAT1 and decreasing the expression of two IFN-α downstream effectors, protein kinase R and 2',5'-oligoadenylate synthetase. Our results offer new insights into the pathogenesis of HBV infection and may provide potential targets for anti-HBV therapy. PMID:22661095

  13. Comparative Functional Analysis of 12 Mammalian IFN-λ4 Orthologs

    PubMed Central

    Paquin, Ashley; Onabajo, Olusegun O.; Tang, Wei

    2016-01-01

    IFN-λ4 is a novel type-III interferon with strong clinical significance in humans. Only a subset of individuals—up to 10% of Asians, 50% of Europeans, and 90% of Africans—carry the ΔG allele of a genetic variant rs368234815-TT/ΔG and are genetically able to produce IFN-λ4 protein. Carriers of the ΔG allele have impaired ability to clear infection with hepatitis C virus (HCV). IFN-λ4 is also predicted to exist and be functionally important in several nonhuman mammals. In this study, we present the first comparative analysis of 12 mammalian IFN-λ4 orthologs in a human hepatic cell line, HepG2, which supports signaling of the human IFN-λ4. We show that despite differences in protein sequences, functional properties of the recombinant human and nonhuman IFN-λ4 proteins are comparable—they are all expressed as predominantly cytoplasmic proteins that are biologically active for induction of interferon signaling. We show that several IFN-λ4 orthologs can be detected by Western blotting, flow cytometry, and confocal imaging using a monoclonal antibody developed for the human IFN-λ4. Studies of IFN-λ4 in animals should help improve our understanding of the biology of this novel clinically important interferon in normal and disease conditions. PMID:26308395

  14. Btk inhibition treats TLR7/IFN driven murine lupus.

    PubMed

    Bender, Andrew T; Pereira, Albertina; Fu, Kai; Samy, Eileen; Wu, Yin; Liu-Bujalski, Lesley; Caldwell, Richard; Chen, Yi-Ying; Tian, Hui; Morandi, Federica; Head, Jared; Koehler, Ursula; Genest, Melinda; Okitsu, Shinji L; Xu, Daigen; Grenningloh, Roland

    2016-03-01

    Bruton's tyrosine kinase (Btk) is expressed in a variety of immune cells and previous work has demonstrated that blocking Btk is a promising strategy for treating autoimmune diseases. Herein, we utilized a tool Btk inhibitor, M7583, to determine the therapeutic efficacy of Btk inhibition in two mouse lupus models driven by TLR7 activation and type I interferon. In BXSB-Yaa lupus mice, Btk inhibition reduced autoantibodies, nephritis, and mortality. In the pristane-induced DBA/1 lupus model, Btk inhibition suppressed arthritis, but autoantibodies and the IFN gene signature were not significantly affected; suggesting efficacy was mediated through inhibition of Fc receptors. In vitro studies using primary human macrophages revealed that Btk inhibition can block activation by immune complexes and TLR7 which contributes to tissue damage in SLE. Overall, our results provide translational insight into how Btk inhibition may provide benefit to a variety of SLE patients by affecting both BCR and FcR signaling. PMID:26821304

  15. CD8(+) T cells mediate RAS-induced psoriasis-like skin inflammation through IFN-γ.

    PubMed

    Gunderson, Andrew J; Mohammed, Javed; Horvath, Frank J; Podolsky, Michael A; Anderson, Cherie R; Glick, Adam B

    2013-04-01

    The RAS signaling pathway is constitutively activated in psoriatic keratinocytes. We expressed activated H-RAS(V12G) in suprabasal keratinocytes of adult mice and observed rapid development of a psoriasis-like skin phenotype characterized by basal keratinocyte hyperproliferation, acanthosis, hyperkeratosis, intraepidermal neutrophil microabscesses, and increased T helper type 1 (Th1)/Th17 and T cell type 1 (Tc1)/Tc17 skin infiltration. The majority of skin-infiltrating CD8(+) T cells coexpressed IFN-γ and IL-17A. When RAS was expressed on a Rag1-/- background, microabscess formation, inducible nitric oxide synthase expression, and keratinocyte hyperproliferation were suppressed. Depletion of CD8(+), but not CD4(+), T cells reduced cutaneous and systemic inflammation, the RAS-induced increase in cutaneous Th17 and IL-17(+) γδ T cells, and epidermal hyperproliferation to levels similar to a Rag1-/- background. Reconstitution of Rag1-/- inducible RAS mice with purified CD8(+) T cells restored microabscess formation and epidermal hyperproliferation. Neutralization of IFN-γ, but not of IL-17A, in CD8(+) T-cell-reconstituted Rag1-/- mice expressing RAS blocked CD8-mediated skin inflammation, inducible nitric oxide synthase expression, and keratinocyte hyperproliferation. These results show that CD8(+) T cells can orchestrate skin inflammation with psoriasis-like pathology in response to constitutive RAS activation in keratinocytes, and this is primarily mediated through IFN-γ. PMID:23151849

  16. Mycophenolate antagonizes IFN-γ-induced catagen-like changes via β-catenin activation in human dermal papilla cells and hair follicles.

    PubMed

    Ryu, Sunhyo; Lee, Yonghee; Hyun, Moo Yeol; Choi, Sun Young; Jeong, Kwan Ho; Park, Young Min; Kang, Hoon; Park, Kui Young; Armstrong, Cheryl A; Johnson, Andrew; Song, Peter I; Kim, Beom Joon

    2014-01-01

    Recently, various immunosuppressant drugs have been shown to induce hair growth in normal hair as well as in alopecia areata and androgenic alopecia; however, the responsible mechanism has not yet been fully elucidated. In this study, we investigate the influence of mycophenolate (MPA), an immunosuppressant, on the proliferation of human dermal papilla cells (hDPCs) and on the growth of human hair follicles following catagen induction with interferon (IFN)-γ. IFN-γ was found to reduce β-catenin, an activator of hair follicle growth, and activate glycogen synthase kinase (GSK)-3β, and enhance expression of the Wnt inhibitor DKK-1 and catagen inducer transforming growth factor (TGF)-β2. IFN-γ inhibited expression of ALP and other dermal papillar cells (DPCs) markers such as Axin2, IGF-1, and FGF 7 and 10. MPA increased β-catenin in IFN-γ-treated hDPCs leading to its nuclear accumulation via inhibition of GSK3β and reduction of DKK-1. Furthermore, MPA significantly increased expression of ALP and other DPC marker genes but inhibited expression of TGF-β2. Therefore, we demonstrate for the first time that IFN-γ induces catagen-like changes in hDPCs and in hair follicles via inhibition of Wnt/β-catenin signaling, and that MPA stabilizes β-catenin by inhibiting GSK3β leading to increased β-catenin target gene and DP signature gene expression, which may, in part, counteract IFN-γ-induced catagen in hDPCs. PMID:25247578

  17. Mycophenolate Antagonizes IFN-γ-Induced Catagen-Like Changes via β-Catenin Activation in Human Dermal Papilla Cells and Hair Follicles

    PubMed Central

    Ryu, Sunhyo; Lee, Yonghee; Hyun, Moo Yeol; Choi, Sun Young; Jeong, Kwan Ho; Park, Young Min; Kang, Hoon; Park, Kui Young; Armstrong, Cheryl A.; Johnson, Andrew; Song, Peter I.; Kim, Beom Joon

    2014-01-01

    Recently, various immunosuppressant drugs have been shown to induce hair growth in normal hair as well as in alopecia areata and androgenic alopecia; however, the responsible mechanism has not yet been fully elucidated. In this study, we investigate the influence of mycophenolate (MPA), an immunosuppressant, on the proliferation of human dermal papilla cells (hDPCs) and on the growth of human hair follicles following catagen induction with interferon (IFN)-γ. IFN-γ was found to reduce β-catenin, an activator of hair follicle growth, and activate glycogen synthase kinase (GSK)-3β, and enhance expression of the Wnt inhibitor DKK-1 and catagen inducer transforming growth factor (TGF)-β2. IFN-γ inhibited expression of ALP and other dermal papillar cells (DPCs) markers such as Axin2, IGF-1, and FGF 7 and 10. MPA increased β-catenin in IFN-γ-treated hDPCs leading to its nuclear accumulation via inhibition of GSK3β and reduction of DKK-1. Furthermore, MPA significantly increased expression of ALP and other DPC marker genes but inhibited expression of TGF-β2. Therefore, we demonstrate for the first time that IFN-γ induces catagen-like changes in hDPCs and in hair follicles via inhibition of Wnt/β-catenin signaling, and that MPA stabilizes β-catenin by inhibiting GSK3β leading to increased β-catenin target gene and DP signature gene expression, which may, in part, counteract IFN-γ-induced catagen in hDPCs. PMID:25247578

  18. Stimulation of IFN-γ production by garlic lectin in mouse spleen cells: involvement of IL-12 via activation of p38 MAPK and ERK in macrophages.

    PubMed

    Dong, Qing; Sugiura, Tsutomu; Toyohira, Yumiko; Yoshida, Yasuhiro; Yanagihara, Nobuyuki; Karasaki, Yuji

    2011-02-15

    Several lectins, present in beans and edible plant products, have immuno-potentiating and anti-tumor activities. We here report the effects of garlic lectin purified from garlic bulbs on the production of cytokines such as interleukin-12 (IL-12) and interferon-γ (IFN-γ) in the mouse. Garlic lectin induced IFN-γ production in spleen cells in a bell-shaped time (24-60 h)- and concentration (0.25-2.0 mg/ml)-dependent manner. The maximal enhancement was observed at 36 h with 0.5 mg/ml of garlic lectin. The stimulatory effect of garlic lectin on IFN-γ production was completely inhibited by both actinomycin D and cycloheximide, an inhibitor of ribosomal protein synthesis and DNA-dependent RNA polymerase, respectively, and was associated with an increase in IFN-γ mRNA level. Garlic lectin also induced IL-12 production in mouse peritoneal macrophages in a concentration (0.25-1.0 mg/ml)- and bell-shaped time (3-24 h)-dependent manner. The lectin increased the phosphorylation of extracellular signal-regulated kinases (ERK) and p38 mitogen-activated protein kinase (p38 MAPK) in macrophages. Furthermore, specific pharmacological inhibitors of ERK kinase (U0126) and p38 MAPK (SB203580) also suppressed the production of IL-12 induced by garlic lectin. The present findings suggest that garlic lectin induces IL-12 production via activation of p38 MAPK and ERK in mouse macrophages, which, in turn, stimulates IFN-γ production through an increase in IFN-γ mRNA in the spleen cells. PMID:20724126

  19. Antibody-dependent enhancement of dengue virus infection inhibits RLR-mediated Type-I IFN-independent signalling through upregulation of cellular autophagy

    PubMed Central

    Huang, Xinwei; Yue, Yaofei; Li, Duo; Zhao, Yujiao; Qiu, Lijuan; Chen, Junying; Pan, Yue; Xi, Juemin; Wang, Xiaodan; Sun, Qiangming; Li, Qihan

    2016-01-01

    Antibody dependent enhancement (ADE) of dengue virus (DENV) infection is identified as the main risk factor of severe Dengue diseases. Through opsonization by subneutralizing or non-neutralizing antibodies, DENV infection suppresses innate cell immunity to facilitate viral replication. However, it is largely unknown whether suppression of type-I IFN is necessary for a successful ADE infection. Here, we report that both DENV and DENV-ADE infection induce an early ISG (NOS2) expression through RLR-MAVS signalling axis independent of the IFNs signaling. Besides, DENV-ADE suppress this early antiviral response through increased autophagy formation rather than induction of IL-10 secretion. The early induced autophagic proteins ATG5-ATG12 participate in suppression of MAVS mediated ISGs induction. Our findings suggest a mechanism for DENV to evade the early antiviral response before IFN signalling activation. Altogether, these results add knowledge about the complexity of ADE infection and contribute further to research on therapeutic strategies. PMID:26923481

  20. Immunologic and MRI markers of the therapeutic effect of IFN-β-1a in relapsing-remitting MS

    PubMed Central

    Tao, Yazhong; Zhang, Xin; Dwyer, Michael G.; Kennedy, Cheryl; Bergsland, Niels; Ramasamy, Deepa; Durfee, Jacqueline; Hojnacki, David; Hayward, Brooke; Dangond, Fernando; Weinstock-Guttman, Bianca

    2015-01-01

    Objectives: To assess potential roles of effector cells and immunologic markers in demyelinating CNS lesion formation, and their modulation by interferon β-1a (IFN-β-1a). Methods: Twenty-three patients with relapsing-remitting multiple sclerosis (RRMS) received IFN-β-1a for 6 months. Immunologic marker results were correlated with brain MRI lesion volumes, and volumes of normal-appearing brain tissue (NABT) with decreasing or increasing voxel-wise magnetization transfer ratio (VW-MTR), suggestive of demyelination and remyelination, respectively. Results: Baseline expression of Th22 cell transcription factor aryl hydrocarbon receptor (AHR) and interleukin (IL)-17F, and percentages of IL-22–expressing CD4+ and CD8+ cells, were significantly higher in patients vs 15 healthy controls; IL-4 in CD4+ cells was lower. Baseline percentage of IL-22–producing CD8+ cells positively correlated with T2 lesion volumes, while percentage of IL-17A–producing CD8+ cells positively correlated with T2 and T1 lesion volumes. IFN-β-1a induced reductions in transcription factor AHR, T-bet, and retinoic acid–related orphan nuclear hormone receptor C (RORc) gene expression, while it increased GATA3's expression in CD4+ cells. Percentages of IL-22-, IL-17A-, and IL-17F-expressing T cells significantly decreased following treatment. Increased percentages of IL-10–expressing CD4+ and CD8+ cells correlated with greater NABT volume with increasing VW-MTR, while decreased percentage of IL-17F–expressing CD4+ cells positively correlated with decreased NABT volume with decreasing VW-MTR. Conclusions: Findings indicate that IFN-β-1a suppresses Th22 and Th17 cell responses, which were associated with decreased MRI-detectable demyelination. Classification of evidence: This pilot study provides Class III evidence that reduced Th22 and Th17 responses are associated with decreased demyelination following IFN-β-1a treatment in patients with RRMS. PMID:26601116

  1. Apoptosis Induced by Mammalian Reovirus Is Beta Interferon (IFN) Independent and Enhanced by IFN Regulatory Factor 3- and NF-κB-Dependent Expression of Noxa

    PubMed Central

    Knowlton, Jonathan J.; Dermody, Terence S.

    2012-01-01

    A variety of signal transduction pathways are activated in response to viral infection, which dampen viral replication and transmission. These mechanisms involve both the induction of type I interferons (IFNs), which evoke an antiviral state, and the triggering of apoptosis. Mammalian orthoreoviruses are double-stranded RNA viruses that elicit apoptosis in vitro and in vivo. The transcription factors interferon regulatory factor 3 (IRF-3) and nuclear factor kappa light-chain enhancer of activated B cells (NF-κB) are required for the expression of IFN-β and the efficient induction of apoptosis in reovirus-infected cells. However, it is not known whether IFN-β induction is required for apoptosis, nor have the genes induced by IRF-3 and NF-κB that are responsible for apoptosis been identified. To determine whether IFN-β is required for reovirus-induced apoptosis, we used type I IFN receptor-deficient cells, IFN-specific antibodies, and recombinant IFN-β. We found that IFN synthesis and signaling are dispensable for the apoptosis of reovirus-infected cells. These results indicate that the apoptotic response following reovirus infection is mediated directly by genes responsive to IRF-3 and NF-κB. Noxa is a proapoptotic BH3-domain-only protein of the Bcl-2 family that requires IRF-3 and NF-κB for efficient expression. We found that Noxa is strongly induced at late times (36 to 48 h) following reovirus infection in a manner dependent on IRF-3 and NF-κB. The level of apoptosis induced by reovirus is significantly diminished in cells lacking Noxa, indicating a key prodeath function for this molecule during reovirus infection. These results suggest that prolonged innate immune response signaling induces apoptosis by eliciting Noxa expression in reovirus-infected cells. PMID:22090144

  2. Rb selectively inhibits innate IFN-β production by enhancing deacetylation of IFN-β promoter through HDAC1 and HDAC8.

    PubMed

    Meng, Jun; Liu, Xingguang; Zhang, Peng; Li, Dong; Xu, Sheng; Zhou, Qingqing; Guo, Meng; Huai, Wanwan; Chen, Xiang; Wang, Quanxing; Li, Nan; Cao, Xuetao

    2016-09-01

    Type I IFN production is tightly controlled by host to generate efficient viral clearance without harmful immunopathology or induction of autoimmune disorders. Epigenetic regulation of type I IFN production in innate immunity and inflammatory disorders remains to be fully understood. Several tumor suppressors have been shown to regulate immune response and inflammation. However, the non-classical functions of tumor suppressors in innate immunity and inflammatory diseases need further identification. Here we report retinoblastoma protein (Rb) deficiency selectively enhanced TLR- and virus-triggered production of IFN-β which thus induced more IFN-α generation in the later phase of innate stimuli, but had no effect on the production of TNF, IL-6 and early phase IFN-α in macrophages. Rb1(fl/fl)Lyz2cre(+) Rb-deficient mice exhibited more resistant to lethal virus infection and more effective clearance of influenza virus. Rb selectively bound Ifnb1 enhancer region, but not the promoter of Ifna4, Tnf and Il6, by interacting with c-Jun, the component of IFN-β enhanceosome. Then Rb recruited HDAC1 and HDAC8 to attenuate acetylation of Histone H3/H4 in Ifnb1 promoter, resulting in suppression of Ifnb1 transcription. Therefore, Rb selectively inhibits innate IFN-β production by enhancing deacetylation of Ifnb1 promoter, exhibiting a previous unknown non-classical role in innate immunity, which also suggests a role of Rb in the regulation of type I IFN production in inflammatory or autoimmune diseases. PMID:27267461

  3. Essential Requirement for IFN Regulatory Factor 7 in Autoantibody Production but Not Development of Nephritis in Murine Lupus.

    PubMed

    Miyagawa, Fumi; Tagaya, Yutaka; Ozato, Keiko; Asada, Hideo

    2016-09-15

    Systemic lupus erythematosus (SLE) is a prototypic systemic autoimmune disease characterized by the production of autoantibodies against nuclear components. Recent genetic studies of SLE patients have revealed that IFN regulatory factor (IRF) 7 gene polymorphisms are associated with an increased risk of SLE, but the precise role of IRF7 in SLE development is not fully understood. We investigated the role of IRF7 in the pathogenesis of SLE using a mouse model and saw a curious dissociation of autoantibody production and development of glomerulonephritis. SLE was chemically induced into IRF7-deficient mice, and glomerulonephritis with deposits of IgG and lipogranulomas were observed after 10 mo. However, these mice failed to produce anti-dsDNA, ssDNA, ribonucleoprotein, and Sm autoantibodies. Following the chemical induction, IRF7-deficient mice expressed substantially lower levels of IFN-stimulated genes than did wild-type mice, but NF-κB target genes were equally upregulated in both strains. Therefore, the type I IFN pathway seems critical for the autoantibody production, but the NF-κB activation is sufficient for the development of glomerulonephritis in this model. Our study thus demonstrates a specific requirement for IRF7 in autoantibody production and uncovers a new layer of complexity in the pathogenesis of SLE. PMID:27527596

  4. TBK1-like transcript negatively regulates the production of IFN and IFN-stimulated genes through RLRs-MAVS-TBK1 pathway.

    PubMed

    Zhang, Lin; Chen, Wen Qin; Hu, Yi Wei; Wu, Xiao Man; Nie, P; Chang, Ming Xian

    2016-07-01

    TANK-binding kinase 1 (TBK1) is an essential serine/threonine-protein kinase required for Toll-like receptor (TLR)- and retinoic acid-inducible gene I (RIG-I) -mediated induction of type I IFN and host antiviral defense. In the present study, TBK1-like transcript, namely TBK1L, was cloned from zebrafish. Compared with TBK1, TBK1L contains an incomplete S_TKc domain, and lacks UBL_TBK1_like domain. Realtime PCR showed that TBK1L was constitutively produced in embryos, early larvae and ZF4 cells, and unchanged in ZF4 cells following SVCV infection. Overexpression of TBK1 but not TBK1L resulted in significant activation of zebrafish IFN1 and IFN3 promoters. Similarly, TBK1L had little impact on the antiviral state of the cells. However, the overexpression of TBK1L negatively regulated the induction of zebrafish IFN1 and/or IFN3 promoters mediated by the retinoic acid-inducible gene I-like receptors (RLRs), MAVS and TBK1. In addition, the overexpression of TBK1L in zebrafish embryos led to the decreased production of many IFN-stimulated genes induced by TBK1. Collectively, these data support that zebrafish TBK1L negatively regulates RLRs-MAVS-TBK1 pathway. PMID:27060200

  5. TRIM68 Negatively Regulates IFN-β Production by Degrading TRK Fused Gene, a Novel Driver of IFN-β Downstream of Anti-Viral Detection Systems

    PubMed Central

    Wynne, Claire; Lazzari, Elisa; Smith, Siobhán; McCarthy, Eoghan M.; Ní Gabhann, Joan; Kallal, Lara E.; Higgs, Rowan; Cryan, Sally Ann; Biron, Christine A.; Jefferies, Caroline A.

    2014-01-01

    In recent years members of the tripartite motif-containing (TRIM) family of E3 ubiquitin ligases have been shown to both positively and negatively regulate viral defence and as such are emerging as compelling targets for modulating the anti-viral immune response. In this study we identify TRIM68, a close homologue of TRIM21, as a novel regulator of Toll-like receptor (TLR)- and RIG-I-like receptor (RLR)-driven type I IFN production. Proteomic analysis of TRIM68-containing complexes identified TRK-fused gene (TFG) as a potential TRIM68 target. Overexpression of TRIM68 and TFG confirmed their ability to associate, with TLR3 stimulation appearing to enhance the interaction. TFG is a known activator of NF-κB via its ability to interact with inhibitor of NF-κB kinase subunit gamma (IKK-γ) and TRAF family member-associated NF-κB activator (TANK). Our data identifies a novel role for TFG as a positive regulator of type I IFN production and suggests that TRIM68 targets TFG for lysosomal degradation, thus turning off TFG-mediated IFN-β production. Knockdown of TRIM68 in primary human monocytes resulted in enhanced levels of type I IFN and TFG following poly(I:C) treatment. Thus TRIM68 targets TFG, a novel regulator of IFN production, and in doing so turns off and limits type I IFN production in response to anti-viral detection systems. PMID:24999993

  6. The Type I IFN-Induced miRNA, miR-21

    PubMed Central

    Yang, Chuan He; Li, Kui; Pfeffer, Susan R.; Pfeffer, Lawrence M.

    2015-01-01

    The interferon (IFN) family of cytokines not only has antiviral properties at various steps in the viral replication cycle, but also anticancer activity through multiple pathways that include inhibiting cell proliferation, regulating cellular responses to inducers of apoptosis and modulating angiogenesis and the immune system. IFNs are known to induce their biological activity through the induction of protein encoding IFN-stimulated genes. However, recent studies have established that IFNs also induce the expression of microRNAs (miRNAs), which are small endogenous non-coding RNAs that suppress gene expression at the post-transcriptional level. MiRNAs play critical roles in tumorigenesis and have been implicated to act as either oncogenes or tumor suppressors in various human cancers. Therefore, IFN-induced miRNAs play an important role, not only in the host response to innate immune response to cancer, but also in the tumorigenic process itself. Furthermore, IFN-induced miRNAs may participate in and/or orchestrate antiviral defense in certain viral infections. In this review, we describe our recent studies on the induction of miR-21 by type I IFN, the role of the STAT3 and NFκB signaling pathways in IFN-induced miR-21 expression, the role of miR-21 in different cancers and the role of miR-21 in regulating the antiviral response. PMID:26610525

  7. TET3 Inhibits Type I IFN Production Independent of DNA Demethylation.

    PubMed

    Xue, Shengjie; Liu, Chang; Sun, Xiujie; Li, Weiyun; Zhang, Chi; Zhou, Xin; Lu, Yao; Xiao, Jun; Li, Chunyang; Xu, Xiaoyan; Sun, Bing; Xu, Guoliang; Wang, Hongyan

    2016-07-26

    Type I interferons (IFNs) play both beneficial and harmful roles in antiviral responses. Precise regulation of host type I IFNs is thus needed to prevent immune dysregulation. Here, we find that the DNA demethylase TET3 is a negative regulator of IFN-β in response to poly(I:C) stimulation or viral infection. Deletion of TET3 enhances antiviral responses, with elevated expression of IFN-β and IFN-stimulated genes. The catalytic domain of TET3 was critical for the suppression of IFN-β production, but TET3 enzymatic activity was dispensable. Instead, the catalytic domain of TET3 interacts with HDAC1 and SIN3A, thus enhancing their binding to the Ifnb1 promoter. Our study demonstrates that TET3 negatively regulates type I IFN production independent of DNA demethylation. This not only sheds light on TET3 as a signaling protein in immune cells for gene regulation but also will help to develop strategies to prevent type I IFN-related disease. PMID:27425624

  8. Cross-regulation of TNF and IFN-α in autoimmune diseases

    PubMed Central

    Palucka, A. Karolina; Blanck, Jean-Philippe; Bennett, Lynda; Pascual, Virginia; Banchereau, Jacques

    2005-01-01

    Cytokines, most particularly TNF and type I IFN (IFN-αβ), have been long considered essential elements in the development of autoimmunity. Identification of TNF in the pathogenesis of rheumatoid arthritis and TNF antagonist therapy represent successes of immunology. IFN-αβ plays a major role in systemic lupus erythematosus (SLE), a prototype autoimmune disease characterized by a break of tolerance to nuclear components. Here, we show that TNF regulates IFN-α production in vitro at two levels. First, it inhibits the generation of plasmacytoid dendritic cells (pDCs), a major producer of IFN-αβ, from CD34+ hematopoietic progenitors. Second, it inhibits IFN-α release by immature pDCs exposed to influenza virus. Neutralization of endogenous TNF sustains IFN-α secretion by pDCs. These findings are clinically relevant, as five of five patients with systemic juvenile arthritis treated with TNF antagonists display overexpression of IFN-α-regulated genes in their blood leukocytes. These results, therefore, might provide a mechanistic explanation for the development of anti-dsDNA antibodies and lupus-like syndrome in patients undergoing anti-TNF therapy. PMID:15728381

  9. Liposome-based HCV vaccine enhances protective cellular immunity and IFN-gamma secretion in mice.

    PubMed

    Abo-Elnazar, S; Moaaz, M; El-Sayed, A; Shalaby, Th; SirEl-Khatim, S

    2013-01-01

    HCV is a worldwide health problem and with the lack of effective treatment, vaccination becomes an urgent task, especially in developing countries. The effective vaccine should elicit long-lasting antibodies but most importantly induce a vigorous, multi-specific cellular immune response that includes both helper and cytotoxic T lymphocytes. Advances in liposome technology account for much of the progress in vaccine delivery systems. Therefore, this study aimed at investigating the potential immunogenicity of HCV core antigen, and assessing the influence of the novel antigen carried on liposomes on T cell proliferation and IFN-gamma production as potent markers of cellular immune response. Several formulations for immunization were prepared, including liposomal encapsulation of the Ag. The study was conducted on a total of 95 female inbred (C57B1/6J) mice divided into five groups including a control group. Spleen lymphocytes were evaluated for cellular proliferation using 3-(4, 5-Dimethylthiazol-2-YI)-2, 5-Diphenyltetrazolium Bromide (MTT) assay and for secretion of IFN-gamma by ELISA. Mice injected with liposomes carrying HCV core Ag (group 1) showed a highly significant increase in splenocytes proliferation (spontaneously and after stimulation with the Ag) compared to all other groups, with a stimulation index (S.I) of 1.47 (P < 0.001). The second highest cellular proliferation was noticed in mice injected with core Ag and CFA (group 2) (S.I = 1.29) with a significant difference from group I (P = 0.001). Mice injected with core Ag alone showed a non-significant difference from the control group (P = 0.126). IFN-gamma level was the highest in liposomal Ag group with a highly significant difference; both spontaneously (56.3 pg/L) and with stimulation (68.32) (P < 0.001) followed by mice injected with core Ag with CFA. In conclusion, Liposomal formulation of HCV peptide vaccine is effective as direct in vivo antigen loading and activation of T cells leading to

  10. IFN-τ acts in a dose-dependent manner on prostaglandin production by buffalo endometrial stromal cells cultured in vitro.

    PubMed

    Chethan, S G; Singh, S K; Nongsiej, J; Rakesh, H B; Singh, R P; Kumar, N; Agarwal, S K

    2014-06-01

    Interferon-τ (IFN-τ) has been recognized as the primary embryonic signal responsible for maternal recognition of pregnancy. Uterine endometrium produces both prostaglandin F2α (PGF2α ) and prostaglandin E2 (PGE2 ). PGF2α is responsible for the luteolysis; however, PGE2 favours establishment of pregnancy by its luteoprotective action. In this study, the dose-response effect of recombinant bovine IFN-τ (rbIFN-τ) on prostaglandin (PG) production by buffalo endometrial stromal cells cultured in vitro was studied. Buffalo endometrial stromal cells were isolated by double enzymatic digestion, initially with trypsin III followed by a cocktail of trypsin III, collagenase type II and DNase I and subsequently cultured till confluence. Further, cells were treated with different doses of rbIFN-τ (0.001, 0.01, 0.1, 1.0 and 10 μg/ml) and keeping a separate set of control. Culture supernatant was collected after 6, 12 and 24 h of treatment. PG levels in the culture supernatant were measured by enzyme immune assay (EIA) and total cellular protein estimated by Bradford method. Results indicated that buffalo endometrial stromal cells following rbIFN-τ treatment enhanced the secretion of both PGE2 and PGF2α , and also its ratio in a strict dose-dependent manner with a significant increase (p < 0.01) in PGE2 production at 1 μg/ml dose of rbIFN-τ and maximal stimulation for both PG was observed at 10 μg/ml. Further, both PG production and its ratio were increased significantly (p < 0.01) in a time-dependent fashion in all the groups at 6, 12 and 24 h post-treatment with highest level achieved at 24 h as compared with control. Absolute levels of PGE2 remained higher than PGF2α indicating PGE2 as the major PG produced by endometrial stromal cells. The dose-dependent response of rbIFN-τ signifies the importance of optimum concentration of IFN-τ for the embryonic development especially during the critical period to establish successful pregnancy. PMID:24612212

  11. Dynamic control of type I IFN signalling by an integrated network of negative regulators.

    PubMed

    Porritt, Rebecca A; Hertzog, Paul J

    2015-03-01

    Whereas type I interferons (IFNs) have critical roles in protection from pathogens, excessive IFN responses contribute to pathology in both acute and chronic settings, pointing to the importance of balancing activating signals with regulatory mechanisms that appropriately tune the response. Here we review evidence for an integrated network of negative regulators of IFN production and action, which function at all levels of the activating and effector signalling pathways. We propose that the aim of this extensive network is to limit tissue damage while enabling an IFN response that is temporally appropriate and of sufficient magnitude. Understanding the architecture and dynamics of this network, and how it differs in distinct tissues, will provide new insights into IFN biology and aid the design of more effective therapeutics. PMID:25725583

  12. A distinct population of nonphagocytic and low level CD4+ null lymphocytes produce IFN-alpha after stimulation by herpes simplex virus-infected cells

    SciTech Connect

    Sandberg, K.; Matsson, P.; Alm, G.V. )

    1990-08-01

    Human PBMC were stimulated for 6 h in vitro by HSV or Sendai virus (SV) and analyzed by flow cytometry. IFN-alpha producing cells (IPC) were identified through their content of IFN-alpha mRNA by in situ hybridization using a 35S-labeled IFN-alpha 2 cRNA probe. The IPC induced by HSV-infected WISH cells lacked capacity to adhere to and phagocytose latex particles. The induction of IFN-alpha by free infectious SV occurring in monocytes was abolished by phagocytosis of latex particles present in the cultures during the induction period. Such latex particles actually enhanced the IFN-alpha response induced by glutaraldehyde-fixed HSV- or SV-infected WISH cells or by free intact HSV. The HSV-induced IPC did not express the CD14 Ag expressed on monocytes. Cell sorting was performed on HSV-induced PBMC labeled with phycoerythrin-conjugated anti-CD3 and FITC-conjugated anti-CD4 mAb. A small population consisting of 1.4% of all PBMC, which was CD3- but expressed low but significant levels of CD4, contained the majority of the IPC with a 50-fold increase of their frequency. This cell population had a forward- and right-angle light scatter different from typical monocytes/macrophages. The results therefore further delineate IPC among PBMC into monocytes, being stimulated by viruses such as SV. Another distinct population of infrequent but highly efficient IPC, tentatively designated natural IFN-alpha producing cells, is activated by stimuli such as HSV.

  13. Investigating the Role of TNF-α and IFN-γ Activation on the Dynamics of iNOS Gene Expression in LPS Stimulated Macrophages

    PubMed Central

    Salim, Taha; Sershen, Cheryl L.; May, Elebeoba E.

    2016-01-01

    Macrophage produced inducible nitric oxide synthase (iNOS) is known to play a critical role in the proinflammatory response against intracellular pathogens by promoting the generation of bactericidal reactive nitrogen species. Robust and timely production of nitric oxide (NO) by iNOS and analogous production of reactive oxygen species are critical components of an effective immune response. In addition to pathogen associated lipopolysaccharides (LPS), iNOS gene expression is dependent on numerous proinflammatory cytokines in the cellular microenvironment of the macrophage, two of which include interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α). To understand the synergistic effect of IFN-γ and TNF-α activation, and LPS stimulation on iNOS expression dynamics and NO production, we developed a systems biology based mathematical model. Using our model, we investigated the impact of pre-infection cytokine exposure, or priming, on the system. We explored the essentiality of IFN-γ priming to the robustness of initial proinflammatory response with respect to the ability of macrophages to produce reactive species needed for pathogen clearance. Results from our theoretical studies indicated that IFN-γ and subsequent activation of IRF1 are essential in consequential production of iNOS upon LPS stimulation. We showed that IFN-γ priming at low concentrations greatly increases the effector response of macrophages against intracellular pathogens. Ultimately the model demonstrated that although TNF-α contributed towards a more rapid response time, measured as time to reach maximum iNOS production, IFN-γ stimulation was significantly more significant in terms of the maximum expression of iNOS and the concentration of NO produced. PMID:27276061

  14. Murine J774 Macrophages Recognize LPS/IFN-g, Non-CpG DNA or Two-CpG DNA-containing Sequences as Immunologically Distinct

    PubMed Central

    Crosby, Lynn; Casey, Warren; Morgan, Kevin; Ni, Hong; Yoon, Lawrence; Easton, Marilyn; Misukonis, Mary; Burleson, Gary; Ghosh, Dipak K.

    2010-01-01

    Specific bacterial lipopolysaccharides (LPS), IFN-γ, and unmethylated cytosine or guanosine-phosphorothioate containing DNAs (CpG) activate host immunity, influencing infectious responses. Macrophages detect, inactivate and destroy infectious particles, and synthetic CpG sequences invoke similar responses of the innate immune system. Previously, murine macrophage J774 cells treated with CpG induced the expression of nitric oxide synthase 2 (NOS2) and cyclo-oxygenase 2 (COX2) mRNA and protein. In this study murine J774 macrophages were exposed to vehicle, interferon γ + lipopolysaccharide (IFN-g/LPS), non-CpG (SAK1), or two-CpG sequence-containing DNA (SAK2) for 0–18 hr and gene expression changes measured. A large number of immunostimulatory and inflammatory changes were observed. SAK2 was a stronger activator of TNFα- and chemokine expression-related changes than LPS/IFN-g. Up regulation included tumor necrosis factor receptor superfamily genes (TNFRSF’s), IL-1 receptor signaling via stress-activated protein kinase (SAPK), NF-κB activation, hemopoietic maturation factors and sonic hedgehog/wingless integration site (SHH/Wnt) pathway genes. Genes of the TGF-β pathway were down regulated. In contrast, LPS/IFN-g -treated cells showed increased levels for TGF-β signaling genes, which may be linked to the observed up regulation of numerous collagens and down regulation of Wnt pathway genes. SAK1 produced distinct changes from LPS/IFN-g or SAK2. Therefore, J774 macrophages recognize LPS/IFN-g, non-CpG DNA or two-CpG DNA-containing sequences as immunologically distinct. PMID:20097302

  15. Characterization of the bovine type I IFN locus: rearrangements, expansions, and novel subfamilies

    PubMed Central

    Walker, Angela M; Roberts, R Michael

    2009-01-01

    Background The Type I interferons (IFN) have major roles in the innate immune response to viruses, a function that is believed to have led to expansion in the number and complexity of their genes, although these genes have remained confined to single chromosomal region in all mammals so far examined. IFNB and IFNE define the limits of the locus, with all other Type I IFN genes except IFNK distributed between these boundaries, strongly suggesting that the locus has broadened as IFN genes duplicated and then evolved into a series of distinct families. Results The Type I IFN locus in Bos taurus has undergone significant rearrangement and expansion compared to mouse and human, however, with the constituent genes separated into two sub-loci separated by >700 kb. The IFNW family is greatly expanded, comprising 24 potentially functional genes and at least 8 pseudogenes. The IFNB (n = 6), represented in human and mouse by one copy, are also present as multiple copies in Bos taurus. The IFNT, which encode a non-virally inducible, ruminant-specific IFN secreted by the pre-implantation conceptus, are represented by three genes and two pseudogenes. The latter have sequences intermediate between IFNT and IFNW. A new Type I IFN family (IFNX) of four members, one of which is a pseudogene, appears to have diverged from the IFNA lineage at least 83 million years ago, but is absent in all other sequenced genomes with the possible exception of the horse, a non-ruminant herbivore. Conclusion In summary, we have provided the first comprehensive annotation of the Type I IFN locus in Bos taurus, thereby providing an insight into the functional evolution of the Type I IFN in ruminants. The diversity and global spread of the ruminant species may have required an expansion of the Type I IFN locus and its constituent genes to provide broad anti-viral protection required for foraging and foregut fermentation. PMID:19393062

  16. Co-incubation with IL-18 potentiates antigen-specific IFN-γ response in a whole-blood stimulation assay for measurement of cell-mediated immune responses in pigs experimentally infected with Lawsonia intracellularis.

    PubMed

    Riber, Ulla; Boesen, Henriette Toft; Jakobsen, Jeanne T; Nguyen, Lien T M; Jungersen, Gregers

    2011-02-15

    The whole-blood interferon-gamma (IFN-γ) assay is a quantitative in vitro assay for a direct read-out of Ag-specific cell-mediated immune (CMI) responses to infectious diseases. The IFN-γ assay is robust in severe intracellular infections like Brucella or mycobacteria, but more difficult to evaluate for less severe or immunocompromising infections. Here we investigated the performance of the assay when recombinant co-stimulatory cytokines IL-12 and/or IL-18 were added along with Ag or PBS to cultures of whole-blood from pigs infected with Lawsonia intracellularis. In pigs recovering from a natural infection, addition of rIL-12 or rIL-18 alone increased the Ag-specific IFN-γ release while addition of both cytokines resulted in increased IFN-γ release also in PBS cultures. In analyses after experimental infections with L. intracellularis, significant increased levels of Ag-specific IFN-γ production were measured in Ag+rIL-18 cultures from infected pigs compared to the background response in PBS+rIL-18 control samples (p<0.01) or to Ag+rIL-18 cultures from non-inoculated control pigs (p<0.05). Flow cytometry identified two lymphocyte subsets as the Ag-specific IFN-γ producers. The highest IFN-γ production was by CD4(+)CD8(+) cells while a more numerous population of CD4(-)CD8(+) cells produced lower amounts of IFN-γ in response to rIL-18 and L. intracellularis Ag. PMID:20889217

  17. IFN-gamma determines distinct clinical outcomes in autoimmune encephalomyelitis.

    PubMed

    Wensky, Allen K; Furtado, Glaucia C; Marcondes, Maria Cecilia Garibaldi; Chen, Shaohua; Manfra, Denise; Lira, Sergio A; Zagzag, David; Lafaille, Juan J

    2005-02-01

    Experimental autoimmune encephalomyelitis (EAE) is an inflammatory disease of the CNS initiated by autoreactive CD4(+) T cells. EAE classically presents with a progressive ascending paralysis and is a model of multiple sclerosis that recapitulates some aspects of the disease. In this report we describe a mouse strain that spontaneously develops a severe, nonclassical form of EAE with 100% incidence. The distinct clinical phenotype is marked initially by a slight head tilt, progressing to a severe head tilt, spinning, or a rotatory motion. Classical EAE spontaneously occurs in myelin basic protein (MBP)-specific TCR transgenic RAG-1(-/-) mice (referred to as T/R(-)), whereas nonclassical EAE spontaneously occurs in T/R(-) IFN-gamma(-/-) mice (T/R(-)gamma(-)). Thus, the TCR recognizes the same Ag (MBP) and uses identical TCR in both cases. The cellular infiltrate in nonclassical EAE is predominantly found in the brainstem and cerebellum, with very little inflammation in the spinal cord, which is primarily affected in classical disease. Importantly, depending on the genetic makeup and priming conditions of the MBP-specific T cells, nonclassical disease can occur in the presence of an inflammatory infiltrate with eosinophilic, neutrophilic, or monocytic characteristics. Finally, we believe that nonclassical spontaneous EAE could be a useful model for the study of some characteristics of multiple sclerosis not observed in classical EAE, such as the inflammatory responses in the brainstem and cerebellum that can cause vertigo. PMID:15661899

  18. CpG-B Oligodeoxynucleotides Inhibit TLR-Dependent and -Independent Induction of Type I IFN in Dendritic Cells

    PubMed Central

    Liu, Yi C.; Gray, Reginald C.; Hardy, Gareth A. D.; Kuchtey, John; Abbott, Derek W.; Emancipator, Steven N.; Harding, Clifford V.

    2010-01-01

    CpG oligodeoxynucleotides (ODNs) signal through TLR9 to induce type I IFN (IFN-αβ) in dendritic cells (DCs). CpG-A ODNs are more efficacious than CpG-B ODNs for induction of IFN-αβ. Because IFN-αβ may contribute to autoimmunity, it is important to identify mechanisms to inhibit induction of IFN-αβ. In our studies, CpG-B ODN inhibited induction of IFN-αβ by CpG-A ODN, whereas induction of TNF-α and IL-12p40 by CpG-A ODN was not affected. CpG-B inhibition of IFN-αβ was observed in FLT3 ligand-induced murine DCs, purified murine myeloid DCs, plasmacytoid DCs, and human PBMCs. CpG-B ODN inhibited induction of IFN-αβ by agonists of multiple receptors, including MyD88-dependent TLRs (CpG-AODN signaling via TLR9, or R837 or Sendai virus signaling via TLR7) and MyD88-independent receptors (polyinosinic:polycytidylic acid signaling via TLR3 or ds break-DNA signaling via a cytosolic pathway). CpG-B ODN did not inhibit the IFN-αβ positive feedback loop second-wave IFN-αβ, because IFN-αβ–induced expression of IFN-αβ was unaffected, and CpG-B inhibition of IFN-αβ was manifested in IFN-αβR−/− DCs, which lack the positive feedback mechanism. Rather, CpG-B ODN inhibited early TLR-induced first wave IFN-α4 and IFN-β. Chromatin immunoprecipitation revealed that association of IFN regulatory factor 1 with the IFN-α4 and IFN-β promoters was induced by CpG-A ODN but not CpG-B ODN. Moreover, CpG-A–induced association of IFN regulatory factor 1 with these promoters was inhibited by CpG-B ODN. Our studies demonstrate a novel mechanism of transcriptional regulation of first-wave IFN-αβ that selectively inhibits induction of IFN-αβ downstream of multiple receptors and may provide targets for future therapeutic inhibition of IFN-αβ expression in vivo. PMID:20181884

  19. Natural Killer Cell Sensing of Infected Cells Compensates for MyD88 Deficiency but Not IFN-I Activity in Resistance to Mouse Cytomegalovirus.

    PubMed

    Cocita, Clément; Guiton, Rachel; Bessou, Gilles; Chasson, Lionel; Boyron, Marilyn; Crozat, Karine; Dalod, Marc

    2015-05-01

    In mice, plasmacytoid dendritic cells (pDC) and natural killer (NK) cells both contribute to resistance to systemic infections with herpes viruses including mouse Cytomegalovirus (MCMV). pDCs are the major source of type I IFN (IFN-I) during MCMV infection. This response requires pDC-intrinsic MyD88-dependent signaling by Toll-Like Receptors 7 and 9. Provided that they express appropriate recognition receptors such as Ly49H, NK cells can directly sense and kill MCMV-infected cells. The loss of any one of these responses increases susceptibility to infection. However, the relative importance of these antiviral immune responses and how they are related remain unclear. In humans, while IFN-I responses are essential, MyD88 is dispensable for antiviral immunity. Hence, a higher redundancy has been proposed in the mechanisms promoting protective immune responses against systemic infections by herpes viruses during natural infections in humans. It has been assumed, but not proven, that mice fail to mount protective MyD88-independent IFN-I responses. In humans, the mechanism that compensates MyD88 deficiency has not been elucidated. To address these issues, we compared resistance to MCMV infection and immune responses between mouse strains deficient for MyD88, the IFN-I receptor and/or Ly49H. We show that selective depletion of pDC or genetic deficiencies for MyD88 or TLR9 drastically decreased production of IFN-I, but not the protective antiviral responses. Moreover, MyD88, but not IFN-I receptor, deficiency could largely be compensated by Ly49H-mediated antiviral NK cell responses. Thus, contrary to the current dogma but consistent with the situation in humans, we conclude that, in mice, in our experimental settings, MyD88 is redundant for IFN-I responses and overall defense against a systemic herpes virus infection. Moreover, we identified direct NK cell sensing of infected cells as one mechanism able to compensate for MyD88 deficiency in mice. Similar mechanisms likely

  20. A role for the transcription factor RelB in IFN-alpha production and in IFN-alpha-stimulated cross-priming.

    PubMed

    Le Bon, Agne; Montoya, Maria; Edwards, Matthew J; Thompson, Clare; Burke, Shannon A; Ashton, Miranda; Lo, David; Tough, David F; Borrow, Persephone

    2006-08-01

    Chimeric mice generated with bone marrow from RelB-deficient (-/-), RelB-heterozygous (+/-) and wild-type (+/+) mice were used to determine how total or partial absence of the transcription factor RelB in haematopoietic cells affects the immune response generated after lymphocytic choriomeningitis virus (LCMV) infection. In RelB(-/-) chimeras, early virus replication was enhanced and LCMV clearance was impaired. Although plasmacytoid dendritic cell numbers were similar, serum interferon (IFN)-alpha levels in RelB(-/-) and RelB(+/-) chimeras were markedly lower than in RelB(+/+) chimeras during early LCMV infection. Further, both RelB(-/-) and RelB(+/-) chimeras mounted a lower-magnitude LCMV-specific CD8(+) T cell response than their RelB(+/+) counterparts, although the LCMV-specific CD8(+) T cells present were differentiated into functional cytotoxic cells. In LCMV-infected RelB(-/-) mice, induction of cross-priming to an independently injected soluble protein, which depends on the IFN-alpha/beta made during the viral infection, was also impaired. Notably, provision of exogenous IFN-alpha did not restore the ability of RelB(-/-) mice to cross-prime. In summary, these results show that the RelB/NF-kappaB pathway is required for optimal IFN-alpha production after LCMV infection and suggest a crucial role for RelB in IFN-alpha-stimulated cross-priming of CD8(+) T cell responses. PMID:16810633

  1. IL-27 Induced by Select Candida spp. via TLR7/NOD2 Signaling and IFN-β Production Inhibits Fungal Clearance.

    PubMed

    Patin, Emmanuel C; Jones, Adam V; Thompson, Aiysha; Clement, Mathew; Liao, Chia-Te; Griffiths, James S; Wallace, Leah E; Bryant, Clare E; Lang, Roland; Rosenstiel, Philip; Humphreys, Ian R; Taylor, Philip R; Jones, Gareth W; Orr, Selinda J

    2016-07-01

    Candida spp. elicit cytokine production downstream of various pathogen recognition receptors, including C-type lectin-like receptors, TLRs, and nucleotide oligomerization domain (NOD)-like receptors. IL-12 family members IL-12p70 and IL-23 are important for host immunity against Candida spp. In this article, we show that IL-27, another IL-12 family member, is produced by myeloid cells in response to selected Candida spp. We demonstrate a novel mechanism for Candida parapsilosis-mediated induction of IL-27 in a TLR7-, MyD88-, and NOD2-dependent manner. Our data revealed that IFN-β is induced by C. parapsilosis, which in turn signals through the IFN-α/β receptor and STAT1/2 to induce IL-27. Moreover, IL-27R (WSX-1)-deficient mice systemically infected with C. parapsilosis displayed enhanced pathogen clearance compared with wild-type mice. This was associated with increased levels of proinflammatory cytokines in the serum and increased IFN-γ and IL-17 responses in the spleens of IL-27R-deficient mice. Thus, our data define a novel link between C. parapsilosis, TLR7, NOD2, IFN-β, and IL-27, and we have identified an important role for IL-27 in the immune response against C. parapsilosis Overall, these findings demonstrate an important mechanism for the suppression of protective immune responses during infection with C. parapsilosis, which has potential relevance for infections with other fungal pathogens. PMID:27259855

  2. Lipoarabinomannan-specific TNF-α and IFN-γ as markers of protective immunity against tuberculosis: a cohort study in an endemic setting.

    PubMed

    Belay, Mulugeta; Legesse, Mengistu; Mihret, Adane; Bekele, Yonas; Bjune, Gunnar; Abebe, Fekadu

    2015-10-01

    Lipoarabinomannan (LAM) is a virulent factor used for entry and survival of Mycobacterium tuberculosis (Mtb) in macrophages. Although the role of LAM for the diagnosis of tuberculosis (TB) has been extensively investigated, its cytokine response during natural Mtb infection in humans is largely unknown. In this study, LAM-specific IFN-γ, TNF-α, and IL-10 levels following whole blood assay were measured in untreated pulmonary TB patients, their contacts and community controls at baseline. In treated patients and contacts, cytokines were also measured at 6 and 12 months. At entry, 52.8% and 74.8% of controls and contacts were QFT-GIT positive, respectively. At baseline, untreated TB patients and contacts had significantly lower IFN-γ and TNF-α response compared to community controls (p < 0.0001). Besides, untreated patients had significantly higher TNF-α and IL-10 response compared to their contacts (p < 0.0001). At 6 months, contacts and treated TB patients had significantly increased INF-γ and TNF-α response (p < 0.0001). In TB patients, IFNincreased 10-fold following chemotherapy suggesting its potential role for treatment monitoring. The data suggests that LAM might have an anti-inflammatory effect during clinical TB and early Mtb infection. The data also suggests that LAM-induced IFN-γ and TNF-α could be used as biomarkers of protective immunity. PMID:26200933

  3. IL-27 Induced by Select Candida spp. via TLR7/NOD2 Signaling and IFN-β Production Inhibits Fungal Clearance

    PubMed Central

    Patin, Emmanuel C.; Jones, Adam V.; Thompson, Aiysha; Clement, Mathew; Liao, Chia-Te; Griffiths, James S.; Wallace, Leah E.; Bryant, Clare E.; Lang, Roland; Rosenstiel, Philip; Humphreys, Ian R.; Taylor, Philip R.

    2016-01-01

    Candida spp. elicit cytokine production downstream of various pathogen recognition receptors, including C-type lectin-like receptors, TLRs, and nucleotide oligomerization domain (NOD)–like receptors. IL-12 family members IL-12p70 and IL-23 are important for host immunity against Candida spp. In this article, we show that IL-27, another IL-12 family member, is produced by myeloid cells in response to selected Candida spp. We demonstrate a novel mechanism for Candida parapsilosis–mediated induction of IL-27 in a TLR7-, MyD88-, and NOD2-dependent manner. Our data revealed that IFN-β is induced by C. parapsilosis, which in turn signals through the IFN-α/β receptor and STAT1/2 to induce IL-27. Moreover, IL-27R (WSX-1)–deficient mice systemically infected with C. parapsilosis displayed enhanced pathogen clearance compared with wild-type mice. This was associated with increased levels of proinflammatory cytokines in the serum and increased IFN-γ and IL-17 responses in the spleens of IL-27R–deficient mice. Thus, our data define a novel link between C. parapsilosis, TLR7, NOD2, IFN-β, and IL-27, and we have identified an important role for IL-27 in the immune response against C. parapsilosis. Overall, these findings demonstrate an important mechanism for the suppression of protective immune responses during infection with C. parapsilosis, which has potential relevance for infections with other fungal pathogens. PMID:27259855

  4. Down modulation of IFN-{gamma} signaling in alveolar macrophages isolated from smokers

    SciTech Connect

    Dhillon, Navneet K.; Murphy, William J.; Filla, Michael B.; Crespo, Ana J.; Latham, Heath A.; O'Brien-Ladner, Amy

    2009-05-15

    The master cytokine, IFN-{gamma} possesses a wide spectrum of biological effects and is crucial for development of the highly activated macrophage phenotype characteristically found during inflammation. However, no data exists regarding the potential influence of cigarette smoke on the status of the expression of the cell surface receptor for IFN-{gamma} (IFN-{gamma}R) on alveolar macrophages (AM) of smokers. Here in, we report reduction in the expression of the IFN-{gamma}R {alpha}-chain on AM of cigarette smokers, when compared with non-smokers. Ensuing from the loss of receptor expression on the AM of smokers there was a decrease in IFN-{gamma}-mediated cell signaling. This included a decrease in the phosphorylation of signal transducer and activator of transcription (STAT)-1 and induction of interferon regulatory factor (IRF)-1. Further, diminished activation/induction of transcription factors did not appear to result from induction of known members of the 'suppressors of cytokine signaling (SOCS)' family. Decreased IFN-{gamma} signal transduction in AM from smokers may have an important implication regarding the use of therapeutic IFN-{gamma} in the lungs of patients that develop respiratory disorders as a result of tobacco use.

  5. Lineage-Specific Expansion of IFIT Gene Family: An Insight into Coevolution with IFN Gene Family

    PubMed Central

    Liu, Ying; Zhang, Yi-Bing; Liu, Ting-Kai; Gui, Jian-Fang

    2013-01-01

    In mammals, IFIT (Interferon [IFN]-induced proteins with Tetratricopeptide Repeat [TPR] motifs) family genes are involved in many cellular and viral processes, which are tightly related to mammalian IFN response. However, little is known about non-mammalian IFIT genes. In the present study, IFIT genes are identified in the genome databases from the jawed vertebrates including the cartilaginous elephant shark but not from non-vertebrates such as lancelet, sea squirt and acorn worm, suggesting that IFIT gene family originates from a vertebrate ancestor about 450 million years ago. IFIT family genes show conserved gene structure and gene arrangements. Phylogenetic analyses reveal that this gene family has expanded through lineage-specific and species-specific gene duplication. Interestingly, IFN gene family seem to share a common ancestor and a similar evolutionary mechanism; the function link of IFIT genes to IFN response is present early since the origin of both gene families, as evidenced by the finding that zebrafish IFIT genes are upregulated by fish IFNs, poly(I:C) and two transcription factors IRF3/IRF7, likely via the IFN-stimulated response elements (ISRE) within the promoters of vertebrate IFIT family genes. These coevolution features creates functional association of both family genes to fulfill a common biological process, which is likely selected by viral infection during evolution of vertebrates. Our results are helpful for understanding of evolution of vertebrate IFN system. PMID:23818968

  6. CD28 Deficiency Enhances Type I IFN Production by Murine Plasmacytoid Dendritic Cells.

    PubMed

    Macal, Monica; Tam, Miguel A; Hesser, Charles; Di Domizio, Jeremy; Leger, Psylvia; Gilliet, Michel; Zuniga, Elina I

    2016-02-15

    Type I IFNs (IFN-I) are key innate mediators that create a profound antiviral state and orchestrate the activation of almost all immune cells. Plasmacytoid dendritic cells (pDCs) are the most powerful IFN-I-producing cells and play important roles during viral infections, cancer, and autoimmune diseases. By comparing gene expression profiles of murine pDCs and conventional DCs, we found that CD28, a prototypic T cell stimulatory receptor, was highly expressed in pDCs. Strikingly, CD28 acted as a negative regulator of pDC IFN-I production upon TLR stimulation but did not affect pDC survival or maturation. Importantly, cell-intrinsic CD28 expression restrained pDC (and systemic) IFN-I production during in vivo RNA and DNA viral infections, limiting antiviral responses and enhancing viral growth early after exposure. Finally, CD28 also downregulated IFN-I response upon skin injury. Our study identified a new pDC regulatory mechanism by which the same CD28 molecule that promotes stimulation in most cells that express it is co-opted to negatively regulate pDC IFN-I production and limit innate responses. PMID:26773151

  7. IFN-γ signaling maintains skin pigmentation homeostasis through regulation of melanosome maturation.

    PubMed

    Natarajan, Vivek T; Ganju, Parul; Singh, Archana; Vijayan, Vinaya; Kirty, Kritika; Yadav, Shalini; Puntambekar, Shraddha; Bajaj, Sonali; Dani, Prachi P; Kar, Hemanta K; Gadgil, Chetan J; Natarajan, Krishnamurthy; Rani, Rajni; Gokhale, Rajesh S

    2014-02-11

    Cellular homeostasis is an outcome of complex interacting processes with nonlinear feedbacks that can span distinct spatial and temporal dimensions. Skin tanning is one such dynamic response that maintains genome integrity of epidermal cells. Although pathways underlying hyperpigmentation cascade are recognized, negative feedback regulatory loops that can dampen the activated melanogenesis process are not completely understood. In this study, we delineate a regulatory role of IFN-γ in skin pigmentation biology. We show that IFN-γ signaling impedes maturation of the key organelle melanosome by concerted regulation of several pigmentation genes. Withdrawal of IFN-γ signal spontaneously restores normal cellular programming. This effect in melanocytes is mediated by IFN regulatory factor-1 and is not dependent on the central regulator microphthalmia-associated transcription factor. Chronic IFN-γ signaling shows a clear hypopigmentation phenotype in both mouse and human skin. Interestingly, IFN-γ KO mice display a delayed recovery response to restore basal state of epidermal pigmentation after UV-induced tanning. Together, our studies delineate a new spatiotemporal role of the IFN-γ signaling network in skin pigmentation homeostasis, which could have implications in various cutaneous depigmentary and malignant disorders. PMID:24474804

  8. Lineage-specific expansion of IFIT gene family: an insight into coevolution with IFN gene family.

    PubMed

    Liu, Ying; Zhang, Yi-Bing; Liu, Ting-Kai; Gui, Jian-Fang

    2013-01-01

    In mammals, IFIT (Interferon [IFN]-induced proteins with Tetratricopeptide Repeat [TPR] motifs) family genes are involved in many cellular and viral processes, which are tightly related to mammalian IFN response. However, little is known about non-mammalian IFIT genes. In the present study, IFIT genes are identified in the genome databases from the jawed vertebrates including the cartilaginous elephant shark but not from non-vertebrates such as lancelet, sea squirt and acorn worm, suggesting that IFIT gene family originates from a vertebrate ancestor about 450 million years ago. IFIT family genes show conserved gene structure and gene arrangements. Phylogenetic analyses reveal that this gene family has expanded through lineage-specific and species-specific gene duplication. Interestingly, IFN gene family seem to share a common ancestor and a similar evolutionary mechanism; the function link of IFIT genes to IFN response is present early since the origin of both gene families, as evidenced by the finding that zebrafish IFIT genes are upregulated by fish IFNs, poly(I:C) and two transcription factors IRF3/IRF7, likely via the IFN-stimulated response elements (ISRE) within the promoters of vertebrate IFIT family genes. These coevolution features creates functional association of both family genes to fulfill a common biological process, which is likely selected by viral infection during evolution of vertebrates. Our results are helpful for understanding of evolution of vertebrate IFN system. PMID:23818968

  9. Respiratory Syncytial Virus Persistence in Murine Macrophages Impairs IFN-β Response but Not Synthesis.

    PubMed

    Rivera-Toledo, Evelyn; Torres-González, Laura; Gómez, Beatriz

    2015-10-01

    Type-I interferon (IFN-I) production is an early response to viral infection and pathogenic viruses have evolved multiple strategies to evade this cellular defense. Some viruses can establish and maintain persistent infections by altering the IFN-I signaling pathway. Here, we studied IFN-I synthesis and response in an in vitro model of persistent infection by respiratory syncytial virus (RSV) in a murine macrophage-like cell line. In this model, interferon regulatory factor 3 was constitutively active and located at nuclei of persistently infected cells, inducing expression of IFN-beta mRNA and protein. However, persistently infected macrophages did not respond in an autocrine manner to the secreted-IFN-beta or to recombinant-IFN-beta, since phosphorylated-STAT1 was not detected by western blot and transcription of the interferon-stimulated genes (ISGs) Mx1 and ISG56 was not induced. Treatment of non-infected macrophages with supernatants from persistently infected cells induced STAT1 phosphorylation and ISGs expression, mediated by the IFN-I present in the supernatants, because blocking the IFN-I receptor inhibited STAT1 phosphorylation. Results suggest that the lack of autocrine response to IFN-I by the host cell may be one mechanism for maintenance of RSV persistence. Furthermore, STAT1 phosphorylation and ISGs expression induced in non-infected cells by supernatants from persistently infected macrophages suggest that RSV persistence may trigger a proinflammatory phenotype in non-infected cells as part of the pathogenesis of RSV infection. PMID:26501312

  10. Respiratory Syncytial Virus Persistence in Murine Macrophages Impairs IFN-β Response but Not Synthesis

    PubMed Central

    Rivera-Toledo, Evelyn; Torres-González, Laura; Gómez, Beatriz

    2015-01-01

    Type-I interferon (IFN-I) production is an early response to viral infection and pathogenic viruses have evolved multiple strategies to evade this cellular defense. Some viruses can establish and maintain persistent infections by altering the IFN-I signaling pathway. Here, we studied IFN-I synthesis and response in an in vitro model of persistent infection by respiratory syncytial virus (RSV) in a murine macrophage-like cell line. In this model, interferon regulatory factor 3 was constitutively active and located at nuclei of persistently infected cells, inducing expression of IFN-beta mRNA and protein. However, persistently infected macrophages did not respond in an autocrine manner to the secreted-IFN-beta or to recombinant-IFN-beta, since phosphorylated-STAT1 was not detected by western blot and transcription of the interferon-stimulated genes (ISGs) Mx1 and ISG56 was not induced. Treatment of non-infected macrophages with supernatants from persistently infected cells induced STAT1 phosphorylation and ISGs expression, mediated by the IFN-I present in the supernatants, because blocking the IFN-I receptor inhibited STAT1 phosphorylation. Results suggest that the lack of autocrine response to IFN-I by the host cell may be one mechanism for maintenance of RSV persistence. Furthermore, STAT1 phosphorylation and ISGs expression induced in non-infected cells by supernatants from persistently infected macrophages suggest that RSV persistence may trigger a proinflammatory phenotype in non-infected cells as part of the pathogenesis of RSV infection. PMID:26501312

  11. NKT cells mediate pulmonary inflammation and dysfunction in murine sickle cell disease through production of IFN-γ and CXCR3 chemokines

    PubMed Central

    Wallace, Kori L.; Marshall, Melissa A.; Ramos, Susan I.; Lannigan, Joanne A.; Field, Joshua J.; Strieter, Robert M.

    2009-01-01

    Ischemia-reperfusion injury (IRI) triggers an inflammatory cascade that is initiated by the activation of CD1d-restricted iNKT cells. In sickle cell disease (SCD), misshapen erythrocytes evoke repeated transient bouts of microvascular IRI. Compared with C57BL/6 controls, NY1DD mice have more numerous and activated (CD69+, interferon-γ+ [IFN-γ+]) lung, liver, and spleen iNKT cells that are hyperresponsive to hypoxia/reoxygenation. NY1DD mice have increased pulmonary levels of IFN-γ, IFN-γ–inducible chemokines (CXCL9, CXCL10), and elevated numbers of lymphocytes expressing the chemokine receptor CXCR3. Treating NY1DD mice with anti-CD1d antibody to inhibit iNKT cell activation reverses baseline pulmonary dysfunction manifested as elevated vascular permeability, decreased arterial oxygen saturation, and increased numbers of activated leukocytes. Anti-CD1d antibodies decrease pulmonary levels of IFN-γ and CXCR3 chemokines. Neutralization of CXCR3 receptors ameliorates pulmonary dysfunction. Crossing NY1DD to lymphocyte-deficient Rag1−/− mice decreases pulmonary dysfunction. This is counteracted by the adoptive transfer of 1 million NKT cells. Like mice, people with SCD have increased numbers of activated circulating iNKT cells expressing CXCR3. Together, these data indicate that iNKT cells play a pivotal role in sustaining inflammation in SCD mice by a pathway involving IFN-γ and production of chemotactic CXCR3 chemokines and that this mechanism may translate to human disease. PMID:19433855

  12. Multiplex cytokine profile from dengue patients: MIP-1beta and IFN-gamma as predictive factors for severity

    PubMed Central

    Bozza, Fernando A; Cruz, Oswaldo G; Zagne, Sonia MO; Azeredo, Elzinandes L; Nogueira, Rita MR; Assis, Edson F; Bozza, Patricia T; Kubelka, Claire F

    2008-01-01

    Background Dengue virus pathogenesis is not yet fully understood and the identification of patients at high risk for developing severe disease forms is still a great challenge in dengue patient care. During the present study, we evaluated prospectively the potential of cytokines present in plasma from patients with dengue in stratifying disease severity. Methods Seventeen-cytokine multiplex fluorescent microbead immunoassay was used for the simultaneous detection in 59 dengue patients. GLM models using bimodal or Gaussian family were determined in order to associate cytokines with clinical manifestations and laboratory diagnosis. Results IL-1β, IFN-γ, IL-4, IL-6, IL-13, IL-7 and GM-CSF were significantly increased in patients with severe clinical manifestations (severe dengue) when compared to mild disease forms (mild dengue). In contrast, increased MIP-1β levels were observed in patients with mild dengue. MIP-1β was also associated with CD56+NK cell circulating rates. IL-1β, IL-8, TNF-α and MCP-1 were associated with marked thrombocytopenia. Increased MCP-1 and GM-CSF levels correlated with hypotension. Moreover, MIP-1β and IFN-γ were independently associated with both dengue severity and disease outcome. Conclusion Our data demonstrated that the use of a multiple cytokine assay platform was suitable for identifying distinct cytokine profiles associated with the dengue clinical manifestations and severity. MIP-β is indicated for the first time as a good prognostic marker in contrast to IFN-γ that was associated with disease severity. PMID:18578883

  13. Viral Inhibition of the IFN-Induced JAK/STAT Signalling Pathway: Development of Live Attenuated Vaccines by Mutation of Viral-Encoded IFN-Antagonists.

    PubMed

    Fleming, Stephen B

    2016-01-01

    The interferon (IFN) induced anti-viral response is amongst the earliest and most potent of the innate responses to fight viral infection. The induction of the Janus kinase/signal transducer and activation of transcription (JAK/STAT) signalling pathway by IFNs leads to the upregulation of hundreds of interferon stimulated genes (ISGs) for which, many have the ability to rapidly kill viruses within infected cells. During the long course of evolution, viruses have evolved an extraordinary range of strategies to counteract the host immune responses in particular by targeting the JAK/STAT signalling pathway. Understanding how the IFN system is inhibited has provided critical insights into viral virulence and pathogenesis. Moreover, identification of factors encoded by viruses that modulate the JAK/STAT pathway has opened up opportunities to create new anti-viral drugs and rationally attenuated new generation vaccines, particularly for RNA viruses, by reverse genetics. PMID:27367734

  14. The activating effect of IFN-γ on monocytes/macrophages is regulated by the LIF–trophoblast–IL-10 axis via Stat1 inhibition and Stat3 activation

    PubMed Central

    Dallagi, Angham; Girouard, Julie; Hamelin-Morrissette, Jovane; Dadzie, Rachel; Laurent, Laetitia; Vaillancourt, Cathy; Lafond, Julie; Carrier, Christian; Reyes-Moreno, Carlos

    2015-01-01

    Interferon gamma (IFN-γ) and leukemia inhibitory factor (LIF) are key gestational factors that may differentially affect leukocyte function during gestation. Because IFN-γ induces a pro-inflammatory phenotype in macrophages and because trophoblast cells are principal targets of LIF in the placenta, we investigated whether and how soluble factors from trophoblast cells regulate the effects of IFN-γ on macrophage activation. IFN-γ reduces macrophage motility, but enhances Stat1 activation, pro-inflammatory gene expression and cytotoxic functions. Soluble factors from villous cytotrophoblasts (vCT+LIF cells) and BeWo cells (BW/ST+LIF cells) that were differentiated in the presence of LIF inhibit macrophage Stat1 activation but inversely sustain Stat3 activation in response to IFN-γ. vCT+LIF cells produce soluble factors that induce Stat3 activation; this effect is partially abrogated in the presence of neutralizing anti-interleukin 10 (IL-10) antibodies. Moreover, soluble factors from BW/ST+LIF cells reduce cell proliferation but enhance the migratory responses of monocytes. In addition, these factors reverse the inhibitory effect of IFN-γ on monocyte/macrophage motility. BW/ST+LIF cells also generate IFN-γ-activated macrophages with enhanced IL-10 expression, but reduced tumor-necrosis factor alpha (TNF-α), CD14 and CD40 expression as well as impaired cytotoxic function. Additional assays performed in the presence of neutralizing anti-IL-10 antibodies and exogenous IL-10 demonstrate that reduced macrophage cytotoxicity and proliferation, but increased cell motility result from the ability of trophoblast IL-10 to sustain Stat3 activation and suppress IFN-γ-induced Stat1 activation. These in vitro studies are the first to describe the regulatory role of the LIF–trophoblast–IL-10 axis in the process of macrophage activation in response to pro-inflammatory cytokines. PMID:25027966

  15. The activating effect of IFN-γ on monocytes/macrophages is regulated by the LIF-trophoblast-IL-10 axis via Stat1 inhibition and Stat3 activation.

    PubMed

    Dallagi, Angham; Girouard, Julie; Hamelin-Morrissette, Jovane; Dadzie, Rachel; Laurent, Laetitia; Vaillancourt, Cathy; Lafond, Julie; Carrier, Christian; Reyes-Moreno, Carlos

    2015-05-01

    Interferon gamma (IFN-γ) and leukemia inhibitory factor (LIF) are key gestational factors that may differentially affect leukocyte function during gestation. Because IFN-γ induces a pro-inflammatory phenotype in macrophages and because trophoblast cells are principal targets of LIF in the placenta, we investigated whether and how soluble factors from trophoblast cells regulate the effects of IFN-γ on macrophage activation. IFN-γ reduces macrophage motility, but enhances Stat1 activation, pro-inflammatory gene expression and cytotoxic functions. Soluble factors from villous cytotrophoblasts (vCT+LIF cells) and BeWo cells (BW/ST+LIF cells) that were differentiated in the presence of LIF inhibit macrophage Stat1 activation but inversely sustain Stat3 activation in response to IFN-γ. vCT+LIF cells produce soluble factors that induce Stat3 activation; this effect is partially abrogated in the presence of neutralizing anti-interleukin 10 (IL-10) antibodies. Moreover, soluble factors from BW/ST+LIF cells reduce cell proliferation but enhance the migratory responses of monocytes. In addition, these factors reverse the inhibitory effect of IFN-γ on monocyte/macrophage motility. BW/ST+LIF cells also generate IFN-γ-activated macrophages with enhanced IL-10 expression, but reduced tumor-necrosis factor alpha (TNF-α), CD14 and CD40 expression as well as impaired cytotoxic function. Additional assays performed in the presence of neutralizing anti-IL-10 antibodies and exogenous IL-10 demonstrate that reduced macrophage cytotoxicity and proliferation, but increased cell motility result from the ability of trophoblast IL-10 to sustain Stat3 activation and suppress IFN-γ-induced Stat1 activation. These in vitro studies are the first to describe the regulatory role of the LIF-trophoblast-IL-10 axis in the process of macrophage activation in response to pro-inflammatory cytokines. PMID:25027966

  16. THYROXINE (T4) CATABOLISM IN HUMAN AND RAT HEPATOCYTES INCREASES FOLLOWING EXPOSURE TO HEPATIC ENZYME INDUCERS

    EPA Science Inventory

    Nuclear receptor agonists phenobarbital (PB), 3-methylcholanthrene (3MC), pregnenolone-16a-carbonitrile (PCN), 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153), and 2,2' ,4,4'-tetrabromodiphenyl ether (BDE 47) decrease serum thyroxine (T4) in rats. This decrease is thought to occur th...

  17. Inhibition of Epstein-Barr virus-mediated capping of CD21/CR2 by alpha interferon (IFN-alpha): immediate antiviral activity of IFN-alpha during the early phase of infection.

    PubMed Central

    Delcayre, A X; Lotz, M; Lernhardt, W

    1993-01-01

    Early events of human B-lymphocyte infection by Epstein-Barr virus involve the virus binding to CD21, capping, and subsequent internalization of the virus-receptor complex. We show here that alpha interferon (IFN-alpha) inhibits the capping of Epstein-Barr virus-CD21 complexes. Synthetic peptides with the CD21 binding motif of IFN-alpha mimic IFN-alpha activity, suggesting that this effect may be mediated by IFN-alpha-CD21 interaction. Our findings demonstrate a novel and immediate mechanism of IFN-alpha action. PMID:8386282

  18. Vaccinia viruses with a serpin gene deletion and expressing IFN-γ induce potent immune responses without detectable replication in vivo

    PubMed Central

    Legrand, Fatema A.; Verardi, Paulo H.; Chan, Kenneth S.; Peng, Yue; Jones, Leslie A.; Yilma, Tilahun D.

    2005-01-01

    In a continuing effort to develop safe and efficacious vaccine and immunotherapeutic vectors, we constructed recombinant vaccinia virus (rVV) vaccines lacking either the B13R (SPI-2) or the B22R (SPI-1) immune-modulating gene and coexpressing IFN-γ. B13R and B22R are nonessential VV immune-modulating genes that have antiapoptotic and antiinflammatory properties with sequence homology to serine protease inhibitors (serpins). IFN-γ is a cytokine with potent immunoregulatory, antineoplastic, and antiviral properties. We observed that these rVVs with a deletion in a serpin gene and expressing IFN-γ replicated to high titers in tissue culture yet were avirulent in both immunocompromised and immunocompetent mice with no detectable viral replication in these animals. A single immunization elicited potent humoral, T helper, and cytotoxic T cell immune responses in mice despite the absence of any detectable virus replication in vivo. IFN-γ coexpression and the inactivation of one or more VV immune-modulating genes provide an optimized method for increasing the safety while maintaining the efficacy of rVV vaccines. This strategy provides a method for developing highly safe and efficacious vaccines for smallpox and other diseases and immunotherapeutic vectors. PMID:15705716

  19. IFN-adjuvanted DNA vaccine against infectious salmon anemia virus: Antibody kinetics and longevity of IFN expression.

    PubMed

    Robertsen, Børre; Chang, Chia-Jung; Bratland, Lisa

    2016-07-01

    Plasmids expressing interferon (IFN) have recently been shown to function as adjuvants in Atlantic salmon when co-injected with a DNA vaccine encoding hemagglutinin-esterase (HE) from infectious salmon anemia virus (ISAV). In this work we have compared the antibody kinetics and the systemic Mx/ISG15 response of fish vaccinated with HE-plasmid using either IFNa plasmid (pIFNa) or pIFNc as adjuvants over a longer time period, i.e. 22 weeks post vaccination (pv). The results showed that the antibody response against ISAV with pIFNa as adjuvant arose earlier (7 weeks pv) than with pIFNc as adjuvant (10 weeks pv), peaked at week 10 and declined at week 22. The antibody response with pIFNc as adjuvant peaked at 16 weeks and kept at this level 22 weeks pv. Fish injected with pIFNc alone expressed high levels of Mx and ISG15 in liver throughout the 22 week period. In contrast, fish injected with pIFNc together with HE-plasmid expressed high levels of Mx and ISG15 in liver for the first 10 weeks, but at week 16 this response was absent in two of three fish at week 16 and was absent in all tested fish at week 22 pv. This suggests that cells expressing HE and IFNc are intact at week 10 pv, but are eliminated by adaptive immune responses after week 10 due to recognition of HE. The longevity of the Mx/ISG15 response in pIFNc treated fish is likely due to the fact that IFNc is a self-antigen of salmon and is not attacked by the adaptive immune system. PMID:27108379

  20. IFN-γ and IL-21 Double Producing T Cells Are Bcl6-Independent and Survive into the Memory Phase in Plasmodium chabaudi Infection.

    PubMed

    Carpio, Victor H; Opata, Michael M; Montañez, Marelle E; Banerjee, Pinaki P; Dent, Alexander L; Stephens, Robin

    2015-01-01

    CD4 T cells are required to fight malaria infection by promoting both phagocytic activity and B cell responses for parasite clearance. In Plasmodium chabaudi infection, one specific CD4 T cell subset generates anti-parasitic IFN-γ and the antibody-promoting cytokine, IL-21. To determine the lineage of these multifunctional T cells, we followed IFN-γ+ effector T cells (Teff) into the memory phase using Ifng-reporter mice. While Ifng+ Teff expanded, the level of the Th1 lineage-determining transcription factor T-bet only peaked briefly. Ifng+ Teff also co-express ICOS, the B cell area homing molecule CXCR5, and other Tfh lineage-associated molecules including Bcl6, the transcription factor required for germinal center (GC) T follicular helper cells (Tfh) differentiation. Because Bcl6 and T-bet co-localize to the nucleus of Ifng+ Teff, we hypothesized that Bcl6 controls the Tfh-like phenotype of Ifng+ Teff cells in P. chabaudi infection. We first transferred Bcl6-deficient T cells into wildtype hosts. Bcl6-deficient T cells did not develop into GC Tfh, but they still generated CXCR5+ IFN-γ+ IL-21+ IL-10+ Teff, suggesting that this predominant population is not of the Tfh-lineage. IL-10 deficient mice, which have increased IFN-γ and T-bet expression, demonstrated expansion of both IFN-γ+ IL-21+ CXCR5+ cells and IFN-γ+ GC Tfh cells, suggesting a Th1 lineage for the former. In the memory phase, all Ifng+ T cells produced IL-21, but only a small percentage of highly proliferative Ifng+ T cells maintained a T-bethi phenotype. In chronic malaria infection, serum IFN-γ correlates with increased protection, and our observation suggests Ifng+ T cells are maintained by cellular division. In summary, we found that Ifng+ T cells are not strictly Tfh derived during malaria infection. T cells provide the host with a survival advantage when facing this well-equipped pathogen, therefore, understanding the lineage of pivotal T cell players will aid in the rational design of an

  1. IFN-γ and TNF-α are involved during Alzheimer disease progression and correlate with nitric oxide production: a study in Algerian patients.

    PubMed

    Belkhelfa, Mourad; Rafa, Hayet; Medjeber, Oussama; Arroul-Lammali, Amina; Behairi, Nassima; Abada-Bendib, Myriam; Makrelouf, Mohamed; Belarbi, Soreya; Masmoudi, Ahmed Nacer; Tazir, Meriem; Touil-Boukoffa, Chafia

    2014-11-01

    Alzheimer's disease (AD) is a neurodegenerative disease leading to a progressive and irreversible loss of mental functions. It is characterized by 3 stages according to the evolution and the severity of the symptoms. This disease is associated with an immune disorder, which appears with significant rise in the inflammatory cytokines and increased production of free radicals such as nitric oxide (NO). Our study aims to investigate interferon (IFN)-γ and tumor necrosis factor-α (TNF-α) involvement in NO production, in vivo and ex vivo, in peripheral blood mononuclear cells from Algerian patients (n=25), according to the different stages of the disease (mild Alzheimer's, moderate Alzheimer's, and severe Alzheimer's) in comparison to mild cognitive impairment (MCI) patients. Interestingly, we observed that in vivo IFN-γ and TNF-α levels assessed in patients with AD in mild and severe stages, respectively, are higher than those observed in patients with moderate stage and MCI. Our in vivo and ex vivo results show that NO production is related to the increased levels of IFN-γ and TNF-α, in mild and severe stages of AD. Remarkably, significant IFN-γ level is only detected in mild stage of AD. Our study suggests that NO production is IFN-γ dependent both in MCI and mild Alzheimer's patients. Further, high levels of NO are associated with an elevation of TNF-α levels in severe stage of AD. Collectively, our data indicate that the proinflammatory cytokine production seems, in part, to be involved in neurological deleterious effects observed during the development of AD through NO pathway. PMID:24831467

  2. Quantifying the Antiviral Effect of IFN on HIV-1 Replication in Cell Culture

    NASA Astrophysics Data System (ADS)

    Ikeda, Hiroki; Godinho-Santos, Ana; Rato, Sylvie; Vanwalscappel, Bénédicte; Clavel, François; Aihara, Kazuyuki; Iwami, Shingo; Mammano, Fabrizio

    2015-06-01

    Type-I interferons (IFNs) induce the expression of hundreds of cellular genes, some of which have direct antiviral activities. Although IFNs restrict different steps of HIV replication cycle, their dominant antiviral effect remains unclear. We first quantified the inhibition of HIV replication by IFN in tissue culture, using viruses with different tropism and growth kinetics. By combining experimental and mathematical analyses, we determined quantitative estimates for key parameters of HIV replication and inhibition, and demonstrate that IFN mainly inhibits de novo infection (33% and 47% for a X4- and a R5-strain, respectively), rather than virus production (15% and 6% for the X4 and R5 strains, respectively). This finding is in agreement with patient-derived data analyses.

  3. PKR Transduces MDA5-Dependent Signals for Type I IFN Induction.

    PubMed

    Pham, Alissa M; Santa Maria, Felicia Gilfoy; Lahiri, Tanaya; Friedman, Eugene; Marié, Isabelle J; Levy, David E

    2016-03-01

    Sensing invading pathogens early in infection is critical for establishing host defense. Two cytosolic RIG-like RNA helicases, RIG-I and MDA5, are key to type I interferon (IFN) induction in response to viral infection. Mounting evidence suggests that another viral RNA sensor, protein kinase R (PKR), may also be critical for IFN induction during infection, although its exact contribution and mechanism of action are not completely understood. Using PKR-deficient cells, we found that PKR was required for type I IFN induction in response to infection by vaccinia virus lacking the PKR antagonist E3L (VVΔE3L), but not by Sendai virus or influenza A virus lacking the IFN-antagonist NS1 (FluΔNS1). IFN induction required the catalytic activity of PKR, but not the phosphorylation of its principal substrate, eIF2α, or the resulting inhibition of host translation. In the absence of PKR, IRF3 nuclear translocation was impaired in response to MDA5 activators, VVΔE3L and encephalomyocarditis virus, but not during infection with a RIG-I-activating virus. Interestingly, PKR interacted with both RIG-I and MDA5; however, PKR was only required for MDA5-mediated, but not RIG-I-mediated, IFN production. Using an artificially activated form of PKR, we showed that PKR activity alone was sufficient for IFN induction. This effect required MAVS and correlated with IRF3 activation, but no longer required MDA5. Nonetheless, PKR activation during viral infection was enhanced by MDA5, as virus-stimulated catalytic activity was impaired in MDA5-null cells. Taken together, our data describe a critical and non-redundant role for PKR following MDA5, but not RIG-I, activation to mediate MAVS-dependent induction of type I IFN through a kinase-dependent mechanism. PMID:26939124

  4. PKR Transduces MDA5-Dependent Signals for Type I IFN Induction

    PubMed Central

    Lahiri, Tanaya; Friedman, Eugene; Marié, Isabelle J.; Levy, David E.

    2016-01-01

    Sensing invading pathogens early in infection is critical for establishing host defense. Two cytosolic RIG-like RNA helicases, RIG-I and MDA5, are key to type I interferon (IFN) induction in response to viral infection. Mounting evidence suggests that another viral RNA sensor, protein kinase R (PKR), may also be critical for IFN induction during infection, although its exact contribution and mechanism of action are not completely understood. Using PKR-deficient cells, we found that PKR was required for type I IFN induction in response to infection by vaccinia virus lacking the PKR antagonist E3L (VVΔE3L), but not by Sendai virus or influenza A virus lacking the IFN-antagonist NS1 (FluΔNS1). IFN induction required the catalytic activity of PKR, but not the phosphorylation of its principal substrate, eIF2α, or the resulting inhibition of host translation. In the absence of PKR, IRF3 nuclear translocation was impaired in response to MDA5 activators, VVΔE3L and encephalomyocarditis virus, but not during infection with a RIG-I-activating virus. Interestingly, PKR interacted with both RIG-I and MDA5; however, PKR was only required for MDA5-mediated, but not RIG-I-mediated, IFN production. Using an artificially activated form of PKR, we showed that PKR activity alone was sufficient for IFN induction. This effect required MAVS and correlated with IRF3 activation, but no longer required MDA5. Nonetheless, PKR activation during viral infection was enhanced by MDA5, as virus-stimulated catalytic activity was impaired in MDA5-null cells. Taken together, our data describe a critical and non-redundant role for PKR following MDA5, but not RIG-I, activation to mediate MAVS-dependent induction of type I IFN through a kinase-dependent mechanism. PMID:26939124

  5. IFN-β Selectively Inhibits IL-2 Production through CREM-Mediated Chromatin Remodeling.

    PubMed

    Otero, Dennis C; Fares-Frederickson, Nancy J; Xiao, Menghong; Baker, Darren P; David, Michael

    2015-06-01

    IFN-β is widely used in the treatment of multiple sclerosis, yet the mechanism facilitating its efficacy remains unclear. IL-2 production by activated T cells, including those mediating autoimmunity, and subsequent autocrine stimulation is vital for T cell expansion and function. In this study, we demonstrate that in mouse and human T cells, IFN-β specifically inhibits the production of IL-2 upon TCR engagement without affecting other cytokines or activation markers. Rather than disrupting TCR signaling, IFN-β alters histone modifications in the IL-2 promoter to retain the locus in an inaccessible configuration. This in turn is mediated through the upregulation of the transcriptional suppressor CREM by IFN-β and consequent recruitment of histone deacetylases to the IL-2 promoter. In accordance, ablation of CREM expression or inhibition of histone deacetylases activity eliminates the suppressive effects of IFN-β on IL-2 production. Collectively, these findings provide a molecular basis by which IFN-β limits T cell responses. PMID:25888642

  6. Nordihydroguaiaretic acid inhibits IFN-gamma-induced STAT tyrosine phosphorylation in rat brain astrocytes.

    PubMed

    Jeon, Sae-Bom; Ji, Kyung-Ae; You, Hye-Jin; Kim, Jae-Hong; Jou, Ilo; Joe, Eun-Hye

    2005-03-11

    The Janus kinase (JAK) and signal transducers and activators of transcription (STAT) signal cascades are major pathways that mediate the inflammatory functions of interferon-gamma (IFN-gamma), an important pro-inflammatory cytokine. Therefore, regulation of JAK/STAT signaling should modulate IFN-gamma-mediated inflammation. In this study, we found that nordihydroguaiaretic acid (NDGA), a well-known lipoxygenase (LO) inhibitor, suppressed IFN-gamma-induced inflammatory responses in brain astrocytes. In the presence of NDGA, interferon regulatory factor-1 expression was significantly reduced. Expression of monocyte chemotactic protein-1 and interferon-gamma inducible protein-10 mRNA in response to IFN-gamma was significantly suppressed in the presence of NDGA, as was tyrosine-phosphorylation of JAK and STAT. However, the 5-LO products, leukotriene B(4) (LTB(4)) and leukotriene C(4), were not detected in cells treated with IFN-gamma, indicating that the effect of NDGA seemed to be independent of 5-LO inhibition. In addition, two other 5-LO inhibitors (Rev5901 and AA861) did not mimic the effect of NDGA, and the 5-LO metabolites, 5-hydroxyeicosatetraenoic acid and LTB(4), were unable to reverse NDGA-driven suppression of STAT activation or affect basal STAT phosphorylation. Taken together, these results suggest that NDGA regulates IFN-gamma-mediated inflammation through mechanisms unrelated to the inhibition of 5-LO. PMID:15694390

  7. IL-12 and type I IFN response of neonatal myeloid DC to human CMV infection.

    PubMed

    Renneson, Joelle; Dutta, Binita; Goriely, Stanislas; Danis, Bénédicte; Lecomte, Sandra; Laes, Jean-François; Tabi, Zsuzsanna; Goldman, Michel; Marchant, Arnaud

    2009-10-01

    Following congenital human CMV (HCMV) infection, 15-20% of infected newborns develop severe health problems whereas infection in immunocompetent adults rarely causes illness. The immaturity of neonatal antigen presenting cells could play a pivotal role in this susceptibility. Neonatal myeloid DC were shown to be deficient in IFN-beta and IL-12 synthesis in response to TLR triggering. We studied the response of cord and adult blood-derived myeloid DC to HCMV infection. Neonatal and adult DC were equally susceptible to in vitro HCMV infection. Among immunomodulatory cytokines, IL-12, IFN-beta and IFN-lambda1 were produced at lower levels by neonatal as compared with adult DC. In contrast, neonatal and adult DC produced similar levels of IFN-alpha and IFN-inducible genes. Microarray analysis indicated that among the more than thousand genes up- or down-regulated by HCMV infection of myeloid DC, 88 were differently regulated between adult and neonatal DC. We conclude that neonatal and adult DC trigger a partly different response to HCMV infection. The deficient IL-12 and mature IFN-alpha production by neonatal DC exposed to HCMV are likely to influence the quality of the T lymphocyte response to HCMV infection in early life. PMID:19637227

  8. Cutting edge: enhancement of antibody responses through direct stimulation of B and T cells by type I IFN.

    PubMed

    Le Bon, Agnes; Thompson, Clare; Kamphuis, Elisabeth; Durand, Vanessa; Rossmann, Cornelia; Kalinke, Ulrich; Tough, David F

    2006-02-15

    Type I IFN (IFN-alphabeta) is induced rapidly by infection and plays a key role in innate antiviral defense. IFN-alphabeta also exerts stimulatory effects on the adaptive immune system and has been shown to enhance Ab and T cell responses. We have investigated the importance of B and T cells as direct targets of IFN-alphabeta during IFN-alpha-mediated augmentation of the Ab response against a soluble protein Ag. Strikingly, the ability of IFN-alpha to stimulate the Ab response and induce isotype switching was markedly reduced in mice in which B cells were selectively deficient for the IFN-alphabetaR. Moreover, IFN-alpha-mediated enhancement of the Ab response was also greatly impaired in mice in which T cells were selectively IFN-alphabetaR-deficient. These results indicate that IFN-alphabetaR signaling in both B and T cells plays an important role in the stimulation of Ab responses by IFN-alphabeta. PMID:16455962

  9. Salmonella Typhimurium Co-Opts the Host Type I IFN System To Restrict Macrophage Innate Immune Transcriptional Responses Selectively.

    PubMed

    Perkins, Darren J; Rajaiah, Rajesh; Tennant, Sharon M; Ramachandran, Girish; Higginson, Ellen E; Dyson, Tristan N; Vogel, Stefanie N

    2015-09-01

    Innate immune inflammatory responses are subject to complex layers of negative regulation at intestinal mucosal surfaces. Although the type I IFN system is critical for amplifying antiviral immunity, it has been shown to play a homeostatic role in some models of autoimmune inflammation. Type I IFN is triggered in the gut by select bacterial pathogens, but whether and how the type I IFN might regulate innate immunity in the intestinal environment have not been investigated in the context of Salmonella enterica serovar Typhimurium (ST). ST infection of human or murine macrophages reveals that IFN-β selectively restricts the transcriptional responses mediated by both the TLRs and the NOD-like receptors. Specifically, IFN-β potently represses ST-dependent innate induction of IL-1 family cytokines and neutrophil chemokines. This IFN-β-mediated transcriptional repression was independent of the effects of IFN-β on ST-induced macrophage cell death, but significantly dependent on IL-10 regulation. We further evaluated ST pathogenesis in vivo following oral inoculation of mice lacking IFN-β. We show that IFN-β(-/-) mice exhibit greater resistance to oral ST infection and a slower spread of ST to distal sterile sites. This work provides mechanistic insight into the relationship between ST and type I IFN, and demonstrates an additional mechanism by which IFN-β may promote spread of enteric pathogens. PMID:26202980

  10. IL-36α induces maturation of Th1-inducing human MDDC and synergises with IFN-γ to induce high surface expression of CD14 and CD11c.

    PubMed

    Higgins, John; Mutamba, Shilla; Mahida, Yashwant; Barrow, Paul; Foster, Neil

    2015-04-01

    We show that IL-36α induced maturation of human MDDCs and stimulated differentiation of IFN-γ producing (Type 1) CD3+ lymphocytes but was not as effective as IL-36β in doing so. For the first time, we also show that IL-36α induced expression of CD14 by MDDCs and this was highly potentiated by co-cultured with IFN-γ. In contrast, lipopolysaccharide (LPS) did not increase CD14 expression by MDDCs, suggesting that if MDDCs represent a physiologically relevant population in vivo, they need to be stimulated by relevant inflammatory cytokines prior to CD14 expression and detection of LPS, expressed by Gram negative bacteria. IFN-γ synergised with IL-36α to restore the high levels of CD11c expression by MDDCs, which was reduced by culture with these cytokines in isolation. IL-36α/IFN-γ synergy also correlated with increased binding of the opsonic complement protein (iC3b) to MDDCs. However although IL-36α increased the phagocytic capacity of MDDCs for Salmonella Typhimurium 4/74 this was not synergistically increased by IFN-γ (P>0.05). In conclusion we report the hitherto unknown effects of IL-36α on the innate cell function of human MDDCs. PMID:25700962

  11. Dengue Virus Activates Membrane TRAIL Relocalization and IFN-α Production by Human Plasmacytoid Dendritic Cells In Vitro and In Vivo

    PubMed Central

    Gandini, Mariana; Gras, Christophe; Azeredo, Elzinandes Leal; Pinto, Luzia Maria de Oliveira; Smith, Nikaïa; Despres, Philippe; da Cunha, Rivaldo Venâncio; de Souza, Luiz José

    2013-01-01

    Background Dengue displays a broad spectrum of clinical manifestations that may vary from asymptomatic to severe and even fatal features. Plasma leakage/hemorrhages can be caused by a cytokine storm induced by monocytes and dendritic cells during dengue virus (DENV) replication. Plasmacytoid dendritic cells (pDCs) are innate immune cells and in response to virus exposure secrete IFN-α and express membrane TRAIL (mTRAIL). We aimed to characterize pDC activation in dengue patients and their function under DENV-2 stimulation in vitro. Methods & Findings Flow cytometry analysis (FCA) revealed that pDCs of mild dengue patients exhibit significantly higher frequencies of mTRAIL compared to severe cases or healthy controls. Plasma levels of IFN-α and soluble TRAIL are increased in mild compared to severe dengue patients, positively correlating with pDC activation. FCA experiments showed that in vitro exposure to DENV-2 induced mTRAIL expression on pDC. Furthermore, three dimension microscopy highlighted that TRAIL was relocalized from intracellular compartment to plasma membrane. Chloroquine treatment inhibited DENV-2-induced mTRAIL relocalization and IFN-α production by pDC. Endosomal viral degradation blockade by chloroquine allowed viral antigens detection inside pDCs. All those data are in favor of endocytosis pathway activation by DENV-2 in pDC. Coculture of pDC/DENV-2-infected monocytes revealed a dramatic decrease of antigen detection by FCA. This viral antigens reduction in monocytes was also observed after exogenous IFN-α treatment. Thus, pDC effect on viral load reduction was mainly dependent on IFN-α production Conclusions This investigation characterizes, during DENV-2 infection, activation of pDCs in vivo and their antiviral role in vitro. Thus, we propose TRAIL-expressing pDCs may have an important role in the outcome of disease. PMID:23755314

  12. Two-Year Follow-up Study of Mycobacterium tuberculosis Antigen-Driven IFN-γ Responses and Macrophage sCD14 Levels After Tuberculosis Contact.

    PubMed

    Druszczynska, Magdalena; Wlodarczyk, Marcin; Kielnierowski, Grzegorz; Kawka, Malwina; Rudnicka, Wieslawa

    2016-06-01

    Clinical data regarding the prediction of active tuberculosis (TB) development in close TB contacts are scarce. To address this problem, we performed a 2-year follow-up study of Mycobacterium tuberculosis (M.tb) antigen-driven IFN-gamma responses and serum levels of soluble macrophage CD14 receptor in individuals with recent or prolonged M.tb exposure. Between June 2011 and June 2013, we studied 60 healthy Polish adults with recent household or long-term work TB contact and individuals without known M.tb exposure. All of them underwent baseline and repeated testing with IGRA (IFN-gamma release assay) and serum sCD14 ELISA quantification. Frequencies of IGRA results differed at the baseline and follow-up testing. IGRA reversions were noticed in almost one-third of Work TB Contacts and no participants from the Household TB Contact group. IGRA conversions were found in 40 % of Household TB Contacts. No correlation between the IGRA result and the sCD14 level was observed. IFN-γ variability has important implications for clinical practice and requires caution in interpreting the results to distinguish new infections from nonspecific inter-individual variations in cytokine responses. The impairment of IFN-γ response in some individuals with prolonged M.tb exposure representing a resistant immune status does not allow considering IGRA results as reliable and credible. Monitoring the serum sCD14 level can reduce the likelihood of a false prediction of active TB development in close TB contacts showing an M.tb-specific increase in the IFN-gamma production in repeated IGRA testing. PMID:27570313

  13. Conditional IFNAR1 ablation reveals distinct requirements of Type I IFN signaling for NK cell maturation and tumor surveillance

    PubMed Central

    Mizutani, Tatsuaki; Neugebauer, Nina; Putz, Eva M.; Moritz, Nadine; Simma, Olivia; Zebedin-Brandl, Eva; Gotthardt, Dagmar; Warsch, Wolfgang; Eckelhart, Eva; Kantner, Hans-Peter; Kalinke, Ulrich; Lienenklaus, Stefan; Weiss, Siegfried; Strobl, Birgit; Müller, Mathias; Sexl, Veronika; Stoiber, Dagmar

    2012-01-01

    Mice with an impaired Type I interferon (IFN) signaling (IFNAR1- and IFNβ-deficient mice) display an increased susceptibility toward v-ABL-induced B-cell leukemia/lymphoma. The enhanced leukemogenesis in the absence of an intact Type I IFN signaling is caused by alterations within the tumor environment. Deletion of Ifnar1 in tumor cells (as obtained in Ifnar1f/f CD19-Cre mice) failed to impact on disease latency or type. In line with this observation, the initial transformation and proliferative capacity of tumor cells were unaltered irrespective of whether the cells expressed IFNAR1 or not. v-ABL-induced leukemogenesis is mainly subjected to natural killer (NK) cell-mediated tumor surveillance. Thus, we concentrated on NK cell functions in IFNAR1 deficient animals. Ifnar1-/- NK cells displayed maturation defects as well as an impaired cytolytic activity. When we deleted Ifnar1 selectively in mature NK cells (by crossing Ncr1-iCre mice to Ifnar1f/f animals), maturation was not altered. However, NK cells derived from Ifnar1f/f Ncr1-iCre mice showed a significant cytolytic defect in vitro against the hematopoietic cell lines YAC-1 and RMA-S, but not against the melanoma cell line B16F10. Interestingly, this defect was not related to an in vivo phenotype as v-ABL-induced leukemogenesis was unaltered in Ifnar1f/f Ncr1-iCre compared with Ifnar1f/f control mice. Moreover, the ability of Ifnar1f/f Ncr1-iCre NK cells to kill B16F10 melanoma cells was unaltered, both in vitro and in vivo. Our data reveal that despite the necessity for Type I IFN in NK cell maturation the expression of IFNAR1 on mature murine NK cells is not required for efficient tumor surveillance. PMID:23170251

  14. Additive loss-of-function proteasome subunit mutations in CANDLE/PRAAS patients promote type I IFN production.

    PubMed

    Brehm, Anja; Liu, Yin; Sheikh, Afzal; Marrero, Bernadette; Omoyinmi, Ebun; Zhou, Qing; Montealegre, Gina; Biancotto, Angelique; Reinhardt, Adam; Almeida de Jesus, Adriana; Pelletier, Martin; Tsai, Wanxia L; Remmers, Elaine F; Kardava, Lela; Hill, Suvimol; Kim, Hanna; Lachmann, Helen J; Megarbane, Andre; Chae, Jae Jin; Brady, Jilian; Castillo, Rhina D; Brown, Diane; Casano, Angel Vera; Gao, Ling; Chapelle, Dawn; Huang, Yan; Stone, Deborah; Chen, Yongqing; Sotzny, Franziska; Lee, Chyi-Chia Richard; Kastner, Daniel L; Torrelo, Antonio; Zlotogorski, Abraham; Moir, Susan; Gadina, Massimo; McCoy, Phil; Wesley, Robert; Rother, Kristina I; Rother, Kristina; Hildebrand, Peter W; Brogan, Paul; Krüger, Elke; Aksentijevich, Ivona; Goldbach-Mansky, Raphaela

    2015-11-01

    Autosomal recessive mutations in proteasome subunit β 8 (PSMB8), which encodes the inducible proteasome subunit β5i, cause the immune-dysregulatory disease chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature (CANDLE), which is classified as a proteasome-associated autoinflammatory syndrome (PRAAS). Here, we identified 8 mutations in 4 proteasome genes, PSMA3 (encodes α7), PSMB4 (encodes β7), PSMB9 (encodes β1i), and proteasome maturation protein (POMP), that have not been previously associated with disease and 1 mutation in PSMB8 that has not been previously reported. One patient was compound heterozygous for PSMB4 mutations, 6 patients from 4 families were heterozygous for a missense mutation in 1 inducible proteasome subunit and a mutation in a constitutive proteasome subunit, and 1 patient was heterozygous for a POMP mutation, thus establishing a digenic and autosomal dominant inheritance pattern of PRAAS. Function evaluation revealed that these mutations variably affect transcription, protein expression, protein folding, proteasome assembly, and, ultimately, proteasome activity. Moreover, defects in proteasome formation and function were recapitulated by siRNA-mediated knockdown of the respective subunits in primary fibroblasts from healthy individuals. Patient-isolated hematopoietic and nonhematopoietic cells exhibited a strong IFN gene-expression signature, irrespective of genotype. Additionally, chemical proteasome inhibition or progressive depletion of proteasome subunit gene transcription with siRNA induced transcription of type I IFN genes in healthy control cells. Our results provide further insight into CANDLE genetics and link global proteasome dysfunction to increased type I IFN production. PMID:26524591

  15. Additive loss-of-function proteasome subunit mutations in CANDLE/PRAAS patients promote type I IFN production

    PubMed Central

    Brehm, Anja; Liu, Yin; Sheikh, Afzal; Marrero, Bernadette; Omoyinmi, Ebun; Zhou, Qing; Montealegre, Gina; Biancotto, Angelique; Reinhardt, Adam; Almeida de Jesus, Adriana; Pelletier, Martin; Tsai, Wanxia L.; Remmers, Elaine F.; Kardava, Lela; Hill, Suvimol; Kim, Hanna; Lachmann, Helen J.; Megarbane, Andre; Chae, Jae Jin; Brady, Jilian; Castillo, Rhina D.; Brown, Diane; Casano, Angel Vera; Gao, Ling; Chapelle, Dawn; Huang, Yan; Stone, Deborah; Chen, Yongqing; Sotzny, Franziska; Lee, Chyi-Chia Richard; Kastner, Daniel L.; Torrelo, Antonio; Zlotogorski, Abraham; Moir, Susan; Gadina, Massimo; McCoy, Phil; Wesley, Robert; Rother, Kristina; Hildebrand, Peter W.; Brogan, Paul; Krüger, Elke; Aksentijevich, Ivona; Goldbach-Mansky, Raphaela

    2015-01-01

    Autosomal recessive mutations in proteasome subunit β 8 (PSMB8), which encodes the inducible proteasome subunit β5i, cause the immune-dysregulatory disease chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature (CANDLE), which is classified as a proteasome-associated autoinflammatory syndrome (PRAAS). Here, we identified 8 mutations in 4 proteasome genes, PSMA3 (encodes α7), PSMB4 (encodes β7), PSMB9 (encodes β1i), and proteasome maturation protein (POMP), that have not been previously associated with disease and 1 mutation in PSMB8 that has not been previously reported. One patient was compound heterozygous for PSMB4 mutations, 6 patients from 4 families were heterozygous for a missense mutation in 1 inducible proteasome subunit and a mutation in a constitutive proteasome subunit, and 1 patient was heterozygous for a POMP mutation, thus establishing a digenic and autosomal dominant inheritance pattern of PRAAS. Function evaluation revealed that these mutations variably affect transcription, protein expression, protein folding, proteasome assembly, and, ultimately, proteasome activity. Moreover, defects in proteasome formation and function were recapitulated by siRNA-mediated knockdown of the respective subunits in primary fibroblasts from healthy individuals. Patient-isolated hematopoietic and nonhematopoietic cells exhibited a strong IFN gene-expression signature, irrespective of genotype. Additionally, chemical proteasome inhibition or progressive depletion of proteasome subunit gene transcription with siRNA induced transcription of type I IFN genes in healthy control cells. Our results provide further insight into CANDLE genetics and link global proteasome dysfunction to increased type I IFN production. PMID:26524591

  16. Identification of CpG oligodeoxynucleotide sequences that induce IFN-gamma production in canine peripheral blood mononuclear cells.

    PubMed

    Kurata, Keigo; Iwata, Akira; Masuda, Kenichi; Sakaguchi, Masahiro; Ohno, Koichi; Tsujimoto, Hajime

    2004-12-28

    Oligodeoxynucleotides containing the cytosine-phosphate-guanine (CpG) motif (CpG-ODNs) have been shown to induce T(H)1 immune responses in animals. Since the sequences of CpG-ODNs that induce T(H)1 responses are considered to vary among animal species, it is necessary to identify effective CpG-ODNs in each animal. In order to identify the sequences of CpG-ODNs that induce T(H)1 responses in dogs, mRNA expression and protein production of IFN-gamma were examined in peripheral blood mononuclear cells (PBMCs) from healthy dogs treated with 11 kinds of synthetic CpG-ODNs. One of the 11 CpG-ODNs (No. 2 CpG-ODN, 5'-GGTGCATCGATGCAGGGGGG-3') was shown to significantly increase mRNA expression and protein production of IFN-gamma in canine PBMCs in a manner dependent on the sequence of the CpG motif. This CpG-ODN also enhanced the expression of IL-12 p40 mRNA in canine PBMCs, whereas expression of IL-12 p35, IL-18, and IL-4 mRNAs was not induced by this CpG-ODN. These results indicate that this CpG-ODN was able to produce IFN-gamma by induction of T(H)1-skewed immune response in dogs. CpG-ODNs may be useful for inducing prophylactic and therapeutic immunity against allergic diseases, viral infection, and tumors in dogs. PMID:15541797

  17. Pretreatment of LPS inhibits IFN-β-induced STAT1 phosphorylation through SOCS3 induced by LPS.

    PubMed

    Ando, Takashi; Komatsu, Takayuki; Naiki, Yoshikazu; Yokochi, Takashi; Watanabe, Daisuke; Koide, Naoki

    2015-12-01

    It has been known that LPS activates macrophages and induces IFN-β production from macrophages. The endogenous IFN-β produced by LPS stimulates the cells, which plays a role in innate immune. However, it was not elucidated yet if the signaling by exogenous IFN-β was influenced by LPS stimulation. In this study, it was found pretreatment of LPS interrupted IFN-β-induced JAK1/STAT1 phosphorylation. LPS pretreatment also reduced IFN-β-induced ISG54, one of IFN-β-inducible genes. Pretreatment with LPS for more than 2h shows inhibitory effect on IFN-β-induced STAT1 phosphorylation but simultaneous treatment or post-treatment of LPS with IFN-β did not show the inhibitory effect. The study using a neutralizing antibody to IFN-β indicated that IFN-β produced by LPS does not take part in the inhibitory effect of LPS. Furthermore, LPS did not affect the expression of IFN αβ receptor. A previous report has shown that LPS-induced SOCS3 inhibited IFN-γ-induced STAT1 phosphorylation, likewise, it was also shown in this study that LPS induced SOCS3 expression and its expression inhibited IFN-β-induced STAT1 phosphorylation which was confirmed by the knockdown study by the siRNA of SOCS3. The real-time PCR and immune-blot studies of SOCS3 indicated that LPS induced SOCS3 is independent of IL-6, IL-10, TNF-α and STAT3, and might depend on p38 activation by LPS. It was suggested that bacterial LPS rather interfere with IFN-β actions, dependent on the timing of LPS stimulation. PMID:26653542

  18. An important role for type III interferon (IFN-lambda/IL-28) in TLR-induced antiviral activity.

    PubMed

    Ank, Nina; Iversen, Marie B; Bartholdy, Christina; Staeheli, Peter; Hartmann, Rune; Jensen, Uffe B; Dagnaes-Hansen, Frederik; Thomsen, Allan R; Chen, Zhi; Haugen, Harald; Klucher, Kevin; Paludan, Søren R

    2008-02-15

    Type III IFNs (IFN-lambda/IL-28/29) are cytokines with type I IFN-like antiviral activities, which remain poorly characterized. We herein show that most cell types expressed both types I and III IFNs after TLR stimulation or virus infection, whereas the ability of cells to respond to IFN-lambda was restricted to a narrow subset of cells, including plasmacytoid dendritic cells and epithelial cells. To examine the role of type III IFN in antiviral defense, we generated IL-28Ralpha-deficient mice. These mice were indistinguishable from wild-type mice with respect to clearance of a panel of different viruses, whereas mice lacking the type I IFN receptor (IFNAR(-/-)) were significantly impaired. However, the strong antiviral activity evoked by treatment of mice with TLR3 or TLR9 agonists was significantly reduced in both IL-28RA(-/-) and IFNAR(-/-) mice. The type I IFN receptor system has been shown to mediate positive feedback on IFN-alphabeta expression, and we found that the type I IFN receptor system also mediates positive feedback on IFN-lambda expression, whereas IL-28Ralpha signaling does not provide feedback on either type I or type III IFN expression in vivo. Finally, using bone-marrow chimeric mice we showed that TLR-activated antiviral defense requires expression of IL-28Ralpha only on nonhemopoietic cells. In this compartment, epithelial cells responded to IFN-lambda and directly restricted virus replication. Our data suggest type III IFN to target a specific subset of cells and to contribute to the antiviral response evoked by TLRs. PMID:18250457

  19. Controlling nuclear JAKs and STATs for specific gene activation by IFN{gamma}

    SciTech Connect

    Noon-Song, Ezra N.; Ahmed, Chulbul M.; Dabelic, Rea; Canton, Johnathan; Johnson, Howard M.

    2011-07-08

    Highlights: {yields} Gamma interferon (IFN{gamma}) and its receptor subunit, IFNGR1, interact with the promoter region of IFN{gamma}-associated genes along with transcription factor STAT1{alpha}. {yields} We show that activated Janus kinases pJAK2 and pJAK1 also associate with IFNGR1 in the nucleus. {yields} The activated Janus kinases are responsible for phosphorylation of tyrosine 41 on histone H3, an important epigenetic event for specific gene activation. -- Abstract: We previously showed that gamma interferon (IFN{gamma}) and its receptor subunit, IFNGR1, interacted with the promoter region of IFN{gamma}-activated genes along with transcription factor STAT1{alpha}. Recent studies have suggested that activated Janus kinases pJAK2 and pJAK1 also played a role in gene activation by phosphorylation of histone H3 on tyrosine 41. This study addresses the question of the role of activated JAKs in specific gene activation by IFN{gamma}. We carried out chromatin immunoprecipitation (ChIP) followed by PCR in IFN{gamma} treated WISH cells and showed association of pJAK1, pJAK2, IFNGR1, and STAT1 on the same DNA sequence of the IRF-1 gene promoter. The {beta}-actin gene, which is not activated by IFN{gamma}, did not show this association. The movement of activated JAK to the nucleus and the IRF-1 promoter was confirmed by the combination of nuclear fractionation, confocal microscopy and DNA precipitation analysis using the biotinylated GAS promoter. Activated JAKs in the nucleus was associated with phosphorylated tyrosine 41 on histone H3 in the region of the GAS promoter. Unphosphorylated JAK2 was found to be constitutively present in the nucleus and was capable of undergoing activation in IFN{gamma} treated cells, most likely via nuclear IFNGR1. Association of pJAK2 and IFNGR1 with histone H3 in IFN{gamma} treated cells was demonstrated by histone H3 immunoprecipitation. Unphosphorylated STAT1 protein was associated with histone H3 of untreated cells. IFN

  20. BINDING OF POLYCHLORINATED BIPHENYLS CLASSIFIED AS EITHER PHENOBARBITONE-, 3-METHYLCHOLANTHRENE- OR MIXED-TYPE INDUCERS TO CYTOSOLIC AH RECEPTOR

    EPA Science Inventory

    It has been postulated that reversible, high-affinity binding of 3-methyl-cholanthrene (MC)-type inducers to a receptor protein (the Ah receptor) in hepatic cytosol is essential for induction of aryl hydrocarbon hydroxylase (AHH) enzymic activity. To test this postulate, the bind...

  1. Memory T cell proliferative responses and IFN-γ productivity sustain long-lasting efficacy of a Cap-based PCV2 vaccine upon PCV2 natural infection and associated disease

    PubMed Central

    2014-01-01

    Porcine circovirus type 2 (PCV2) vaccination represents an important measure to cope with PCV2 infection; however, data regarding the modulation of the immune cell compartment are still limited, especially under field conditions. This study is aimed at investigating the features of the cellular immune response in conventional piglets induced by vaccination using a capsid (Cap) protein-based PCV2 vaccine compared to unvaccinated animals when exposed to PCV2 natural infection. Immune reactivity was evaluated by quantifying peripheral cell subsets involved in the anti-viral response and characterizing the interferon-gamma (IFN-γ) secreting cell (SC) responsiveness both in vivo and upon in vitro whole PCV2 recall. The vaccination triggered an early and intense IFN-γ secreting cell response and induced the activation of peripheral lymphocytes. The early increase of IFN-γ SC frequencies resulted in a remarkable and transient tendency to increased IFN-γ productivity in vaccinated pigs. In vaccinated animals, soon before the onset of infection occurred 15-16 weeks post-vaccination, the recalled PCV2-specific immune response was characterized by moderate PCV2-specific IFN-γ secreting cell frequencies and augmented productivity together with reactive CD4+CD8+ memory T cells. Conversely, upon infection, unvaccinated animals showed very high frequencies of IFN-γ secreting cells and a tendency to lower productivity, which paralleled with effector CD4–CD8+ cytotoxic cell responsiveness. The study shows that PCV2 vaccination induces a long-lasting immunity sustained by memory T cells and IFN-γ secreting cells that potentially played a role in preventing the onset of infection; the extent and duration of this reactivity can be an important feature for evaluating the protective immunity induced by vaccination. PMID:24735253

  2. PDGF-BB Promotes Type I IFN-Dependent Vascular Alterations and Monocyte Recruitment in a Model of Dermal Fibrosis.

    PubMed

    Cho, John S; Fang, Terry C; Reynolds, Taylor L; Sofia, Daniel J; Hamann, Stefan; Burkly, Linda C

    2016-01-01

    Systemic sclerosis (SSc) is a chronic autoimmune disorder that can result in extensive tissue damage in the skin and, in advanced cases, internal organs. Vasculopathy, aberrant immune activation, and tissue fibrosis are three hallmarks of the disease that have been identified, with vasculopathy and aberrant immunity being amongst the earliest events. However, a mechanistic link between these processes has not been established. Here, we have identified a novel role of platelet derived growth factor-BB (PDGF-BB)/PDGFRβ activation in combination with dermal injury induced by bleomycin as a driver of early, aberrant expression of interferon stimulatory genes (ISGs) and inflammatory monocyte infiltration. Activation of PDGFRβ in combination with bleomycin-induced dermal injury resulted in increased dermal thickness, vascular density, monocyte/macrophage infiltration, and exacerbation of tissue injury. Many of these features were dependent on IFNAR-signaling, and an increase in the number of interferon-beta (IFN-β) producing monocytes cells was found in the skin lesions. Taken together, these results identify a novel link between PDGFRβ activation, and Type I IFN-driven vascular maintenance and monocyte/macrophage cell recruitment, and provide a potential explanation linking key features of SSc that were previously thought to be unrelated. PMID:27618690

  3. Effectiveness of electrochemotherapy after IFN-α adjuvant therapy of melanoma patients

    PubMed Central

    Hribernik, Andrejc; Cemazar, Maja; Sersa, Gregor; Bosnjak, Maša

    2016-01-01

    Background The combination of electrochemotherapy with immuno-modulatory treatments has already been explored and proven effective. However, the role of interferon alpha (IFN-α) adjuvant therapy of melanoma patients and implication on electrochemotherapy effectiveness has not been explored yet. Therefore, the aim of the study was to retrospectively evaluate the effectiveness and safety of electrochemotherapy after the previous adjuvant treatment with IFN-α in melanoma patients. Patients and methods The study was a retrospective single-center observational analysis of the patients with advanced melanoma, treated with electrochemotherapy after previous IFN-α adjuvant therapy. Five patients, treated between January 2008 and December 2014, were included into the study, regardless of the time point of IFN-α adjuvant therapy. Results Electrochemotherapy of recurrent melanoma after the IFN-α adjuvant therapy proved to be a safe and effective treatment. Patients with one or two metastases responded completely. Among patients with multiple metastases, there was a variable response rate. In one patient all 23 metastases responded completely, in second patient more than 85% of all together 80 metastases responded completely and in third patient all 5 metastases had partial response. Taking into account all metastases from all patients together there was an 85% complete response rate. Conclusions The study showed that electrochemotherapy of recurrent melanoma after the IFN-α adjuvant therapy is a safe and effective treatment modality, which results in a high complete response rate, not only in single metastasis, but also in multiple metastases. The high complete response rate might be due to an IFN-α immune-editing effect, however, further studies with a larger number of patients are needed to support this presumption. PMID:27069446

  4. IL-4 acts as a homeostatic regulator of IL-2-induced TNF and IFN-gamma.

    PubMed Central

    Bello-Fernandez, C; Oblakowski, P; Meager, A; Duncombe, A S; Rill, D M; Hoffbrand, A V; Brenner, M K

    1991-01-01

    Interleukin-4 (IL-4) is a cytokine secreted by interleukin-2 (IL-2)-activated lymphocytes. IL-2-stimulated lymphocytes also secrete two cytokines, tumour necrosis factor (TNF) and gamma-interferon (IFN-gamma), which contribute to effector function and which may themselves recruit fresh, cytokine-secreting effector cells. We have now investigated whether the IL-4 induced is able to homeostatically regulate secretion of the TNF and IFN-gamma. Peripheral blood mononuclear cells or lymphocytes from normal donors and from patients with neoplastic disease were cultured in the presence of IL-2 alone, IL-4 alone or with both cytokines. IL-2 induced high levels of TNF and IFN-gamma secretion in both groups. The addition of recombinant IL-4 to these IL-2-stimulated cultures lead to significant inhibition of IFN-gamma and TNF production. IFN-gamma secretion was reduced by 50-99% in normal donors and by between 11% and 99% in patients (P less than 0.001). TNF levels induced by IL-2 were similarly reduced by IL-4 both in normal donors (P less than 0.003) and in patients (P less than 0.01). These inhibitory effects were produced by IL-4 at doses of IL-2 attainable in vivo. Inhibition appears to represent a homeostatic regulatory mechanism which may limit recruitment of fresh activated killer (AK) cells. When endogenous IL-4 activity in IL-2-activated lymphocytes was blocked by anti-IL-4 antibody, significantly higher levels of IFN-gamma and TNF were secreted (P less than 0.05). Since both TNF and IFN-gamma may contribute to the anti-neoplastic action of IL-2, manipulating the level of IL-4 activity in vivo could augment the benefits of IL-2 immunotherapy. PMID:1901829

  5. IFN-β improves BCG immunogenicity by acting on DC maturation

    PubMed Central

    Giacomini, Elena; Remoli, Maria Elena; Gafa, Valérie; Pardini, Manuela; Fattorini, Lanfranco; Coccia, Eliana M.

    2009-01-01

    Given the variable protective efficacy provided by Mycobacterium bovis bacillus Calmette-Guérin (BCG), there is an urgent need to develop new vaccines against tuberculosis. As dendritic cells (DC) play a critical role in initiating and regulating a protective T cell response against the pathogens, the comprehension of mycobacterium-induced modulation of DC functions is critical to pinpoint new, immunological strategies. To this end, a comparative analysis of the effect induced by BCG and Mycobacterium tuberculosis (Mtb) infection on the DC immunophenotype indicated that BCG is less efficient in inducing DC maturation than Mtb. In addition, BCG-infected DC poorly expressed IFN-β and displayed a reduced production of IL-12 as compared with Mtb-stimulated cells. The impaired expression of IL-12p35 and IFN-β is likely a result of the inability of BCG to induce the activation of the IFN regulatory factor-3. Taking into account these data, we sought to investigate whether the exogenous addition of IFN-β, a cytokine that exerts important effects on the immune system, could enhance the Th1-polarizing capacity of BCG-infected DC. Interestingly, when DC infected by BCG were pretreated in vitro with IFN-β, they displayed a fully mature phenotype and released a significant amount of bioactive IL-12p70, which resulted in an enhanced Th1 response. This study demonstrates that IFN-β potentiates DC immunological functions following BCG infection, thus suggesting IFN-β as a possible candidate as vaccine adjuvant. PMID:19056860

  6. T lymphocyte-derived TNF and IFN-γ repress HFE expression in cancer cells.

    PubMed

    Reuben, Alexandre; Godin-Ethier, Jessica; Santos, Manuela M; Lapointe, Réjean

    2015-06-01

    The immune system and tumors are closely intertwined initially upon tumor development. During this period, tumors evolve to promote self-survival through immune escape, including by targeting crucial components involved in the presentation of antigens to the immune system in order to avoid recognition. Accordingly, components involved in MHC I presentation of tumor antigens are often mutated and down-regulated targets in tumors. On the other hand, the immune system has been shown to influence tumors through production of immunosuppressive cytokines, recruitment and polarization of cells favoring or impeding tumor escape or through production of anti-tumor cytokines promoting tumor rejection. We previously discovered that the hemochromatosis protein HFE, a negative regulator of iron absorption, dampens classical MHC I antigen presentation. In this study, we evaluated the impact of activated T lymphocytes purified from peripheral blood mononuclear cells (PBMC) on HFE expression in tumor cell lines. We co-cultured tumor cell lines from melanoma, lung, and kidney cancers with anti-CD3-activated PBMC and established that HFE expression is increased in tumor cell lines compared to healthy tissues, whilst being down-regulated significantly upon exposure to activated PBMC. HFE down-regulation was mediated by both CD4 and CD8 T lymphocytes, through production of soluble mediators, namely TNF and IFN-γ. These results suggest that the immune system may modulate tumor HFE expression in inflammatory conditions in order to regulate MHC I antigen presentation and promote tumor clearance. PMID:25700349

  7. Rhinovirus stimulated IFN-α production: how important are plasmacytoid DCs, monocytes and endosomal pH?

    PubMed Central

    Xi, Yang; Finlayson, Arvid; White, Oliva J; Carroll, Melanie L; Upham, John W

    2015-01-01

    Human rhinovirus (HRV) infection is a major cause of asthma exacerbations, which appears to be linked to a defective innate immune response to infection. Although the type I interferons (IFN-α and IFN-β) have a critical role in protecting against most viral infections, the cells responsible for IFN production in response to HRV and the relative importance of pattern recognition receptors located in endosomes has not been fully elucidated. In the current study we demonstrate that, using intracellular flow cytometry, >90% of the IFN-α-producing cells in human blood mononuclear cells following HRV16 exposure are plasmacytoid dendritic cells, whereas monocytes and myeloid dendritic cells contribute only 10% and <1%, respectively, of the IFN-α production. Bafilomycin and chloroquine, agents that inhibit the function of endosomal toll-like receptors (TLRs), significantly reduced the capacity of TLR3-, TLR7- and TLR-9-stimulated cells to produce IFN-α and the IFN-induced chemokine CXCL10 (IP-10). In contrast, only bafilomycin (but not chloroquine) effectively suppressed HRV16-stimulated IFN-α and IP-10 production, whereas neither bafilomycin or chloroquine inhibited HRV16-stimulated interleukin-6 release. Attempts to block IFN-α production with commercially available TLR-specific oligonucleotides were unsuccessful due to major ‘off-target' effects. These findings suggest that among circulating haemopoietic cells, plasmacytoid dendritic cells and TLRs located within endosomes are critical for inducing efficient IFN-I production in response to HRVs. PMID:26682054

  8. Association of IFN-γ and P2X7 Receptor Gene Polymorphisms in Susceptibility to Tuberculosis Among Iranian Patients.

    PubMed

    Shamsi, Mahdi; Zolfaghari, Mohammad Reza; Farnia, Parissa

    2016-03-01

    Interferon-gamma (IFN-γ) and P2X7 receptor are crucial for host defence against mycobacterial infections. Recent studies have indicated that IFN-γ, IFN-γ receptor 1 (IFN-γR1) andP2X7 gene polymorphisms are associated with susceptibility to pulmonary tuberculosis (TB). However, the relationship between IFN-γ and P2X7 polymorphism and TB susceptibility remains inconclusive in Iranian population. For this reason, single nucleotide polymorphisms (SNPs) in IFN-γ (G+2109A), IFN-γR1 (G-611A) and P2X7 genes (at -762, 1513 position) in patients (n = 100) were assessed using PCR-RFLP. Data were analysed with SPSS version 18. For the 2109 loci of IFN-γ gene, the frequency of mutant alleles between patients and controls were not statistically significant. However, there was a significant difference between the TB patient and controls for -611 alleles of IFN-γR1 (P = 0.01). Additionally, the frequency of P2X7 gene polymorphisms (SNP-762 and 1513) between patients and controls was statistically significant. In conclusions, our study revealed a significant association of IFN-γR1 and P2X7 genes polymorphisms with risk of developing TB in Iranian population. PMID:27020872

  9. MOV10 Provides Antiviral Activity against RNA Viruses by Enhancing RIG-I-MAVS-Independent IFN Induction.

    PubMed

    Cuevas, Rolando A; Ghosh, Arundhati; Wallerath, Christina; Hornung, Veit; Coyne, Carolyn B; Sarkar, Saumendra N

    2016-05-01

    Moloney leukemia virus 10, homolog (MOV10) is an IFN-inducible RNA helicase, associated with small RNA-induced silencing. In this article, we report that MOV10 exhibits antiviral activity, independent of its helicase function, against a number of positive- and negative-strand RNA viruses by enhancing type I IFN induction. Using a number of genome-edited knockout human cells, we show that IFN regulatory factor 3-mediated IFN induction and downstream IFN signaling through IFN receptor was necessary to inhibit virus replication by MOV10. MOV10 enhanced IFN regulatory factor 3-mediated transcription of IFN. However, this IFN induction by MOV10 was unique and independent of the known retinoic acid-inducible gene I/mitochondrial antiviral-signaling protein-mediated RNA-sensing pathway. Upon virus infection, MOV10 specifically required inhibitor of κB kinase ε, not TANK-binding kinase 1, for its antiviral activity. The important role of MOV10 in mediating antiviral signaling was further supported by the finding that viral proteases from picornavirus family specifically targeted MOV10 as a possible innate immune evasion mechanism. These results establish MOV10, an evolutionary conserved protein involved in RNA silencing, as an antiviral gene against RNA viruses that uses an retinoic acid-inducible gene I-like receptor-independent pathway to enhance IFN response. PMID:27016603

  10. IFN-λ Inhibits MiR-122 Transcription through a Stat3-HNF4α Inflammatory Feedback Loop in an IFN-α Resistant HCV Cell Culture System

    PubMed Central

    Aboulnasr, Fatma; Hazari, Sidhartha; Nayak, Satyam; Chandra, Partha K.; Panigrahi, Rajesh; Ferraris, Pauline; Chava, Srinivas; Kurt, Ramazan; Song, Kyongsub; Dash, Asha; Balart, Luis A.; Garry, Robert F.; Wu, Tong; Dash, Srikanta

    2015-01-01

    Background HCV replication in persistently infected cell culture remains resistant to IFN-α/RBV combination treatment, whereas IFN-λ1 induces viral clearance. The antiviral mechanisms by which IFN-λ1 induces sustained HCV clearance have not been determined. Aim To investigate the mechanisms by which IFN-λ clears HCV replication in an HCV cell culture model. Methods IFN-α sensitive (S3-GFP) and resistant (R4-GFP) cells were treated with equivalent concentrations of either IFN-α or IFN-λ. The relative antiviral effects of IFN-α and IFN-λ1 were compared by measuring the HCV replication, quantification of HCV-GFP expression by flow cytometry, and viral RNA levels by real time RT-PCR. Activation of Jak-Stat signaling, interferon stimulated gene (ISG) expression, and miRNA-122 transcription in S3-GFP and R4-GFP cells were examined. Results We have shown that IFN-λ1 induces HCV clearance in IFN-α resistant and sensitive replicon cell lines in a dose dependent manner through Jak-Stat signaling, and induces STAT 1 and STAT 2 activation, ISRE-luciferase promoter activation and ISG expression. Stat 3 activation is also involved in IFN-λ1 induced antiviral activity in HCV cell culture. IFN-λ1 induced Stat 3 phosphorylation reduces the expression of hepatocyte nuclear factor 4 alpha (HNF4α) through miR-24 in R4-GFP cells. Reduced expression of HNF4α is associated with decreased expression of miR-122 resulting in an anti-HCV effect. Northern blot analysis confirms that IFN-λ1 reduces miR-122 levels in R4-GFP cells. Our results indicate that IFN-λ1 activates the Stat 3-HNF4α feedback inflammatory loop to inhibit miR-122 transcription in HCV cell culture. Conclusions In addition to the classical Jak–Stat antiviral signaling pathway, IFN-λ1 inhibits HCV replication through the suppression of miRNA-122 transcription via an inflammatory Stat 3–HNF4α feedback loop. Inflammatory feedback circuits activated by IFNs during chronic inflammation expose non

  11. Collaborative study for the validation of an improved HPLC assay for recombinant IFN-alfa-2.

    PubMed

    Jönsson, K H; Daas, A; Buchheit, K H; Terao, E

    2016-01-01

    The current European Pharmacopoeia (Ph. Eur.) texts for Interferon (IFN)-alfa-2 include a nonspecific photometric protein assay using albumin as calibrator and a highly variable cell-based assay for the potency determination of the protective effects. A request was expressed by the Official Medicines Control Laboratories (OMCLs) for improved methods for the batch control of recombinant interferon alfa-2 bulk and market surveillance testing of finished products, including those formulated with Human Serum Albumin (HSA). A HPLC method was developed at the Medical Products Agency (MPA, Sweden) for the testing of IFN-alfa-2 products. An initial collaborative study run under the Biological Standardisation Programme (BSP; study code BSP039) revealed the need for minor changes to improve linearity of the calibration curves, assay reproducibility and robustness. The goal of the collaborative study, coded BSP071, was to transfer and further validate this improved HPLC method. Ten laboratories participated in the study. Four marketed IFN-alfa-2 preparations (one containing HSA) together with the Ph. Eur. Chemical Reference Substance (CRS) for IFN-alfa-2a and IFN-alfa-2b, and in-house reference standards from two manufacturers were used for the quantitative assay. The modified method was successfully transferred to all laboratories despite local variation in equipment. The resolution between the main and the oxidised forms of IFN-alfa-2 was improved compared to the results from the BSP039 study. The improved method even allowed partial resolution of an extra peak after the principal peak. Symmetry of the main IFN peak was acceptable for all samples in all laboratories. Calibration curves established with the Ph. Eur. IFN-alfa-2a and IFN-alfa-2b CRSs showed excellent linearity with intercepts close to the origin and coefficients of determination greater than 0.9995. Assay repeatability, intermediate precision and reproducibility varied with the tested sample within acceptable

  12. Dengue Virus Control of Type I IFN Responses: A History of Manipulation and Control.

    PubMed

    Castillo Ramirez, Jorge Andrés; Urcuqui-Inchima, Silvio

    2015-06-01

    The arthropod-borne diseases caused by dengue virus (DENV) are a major and emerging problem of public health worldwide. Infection with DENV causes a series of clinical manifestations ranging from mild flu syndrome to severe diseases that include hemorrhage and shock. It has been demonstrated that the innate immune response plays a key role in DENV pathogenesis. However, in recent years, it was shown that DENV evades the innate immune response by blocking type I interferon (IFN-I). It has been demonstrated that DENV can inhibit both the production and the signaling of IFN-I. The viral proteins, NS2A and NS3, inhibit IFN-I production by degrading cellular signaling molecules. In addition, the viral proteins, NS2A, NS4A, NS4B, and NS5, can inhibit IFN-I signaling by blocking the phosphorylation of the STAT1 and STAT2 molecules. Finally, NS5 mediates the degradation of STAT2 using the proteasome machinery. In this study, we briefly review the most recent insights regarding the IFN-I response to DENV infection and its implication for pathogenesis. PMID:25629430

  13. The synergistic interaction between the calcineurin B subunit and IFN-γ enhances macrophage antitumor activity

    PubMed Central

    Su, Z; Yang, R; Zhang, W; Xu, L; Zhong, Y; Yin, Y; Cen, J; DeWitt, J P; Wei, Q

    2015-01-01

    Macrophages are involved in tumor growth and progression. They infiltrate into tumors and cause inflammation, which creates a microenvironment favoring tumor growth and metastasis. However, certain stimuli may induce macrophages to act as tumor terminators. Here we report that the calcineurin B subunit (CnB) synergizes with IFN-γ to make macrophages highly cytotoxic to cancer cells. Furthermore, CnB and IFN-γ act synergistically to polarize mouse tumor-associated macrophages, as well as human monocyte-derived macrophages to an M1-like phenotype. This synergy is mediated by the crosstalk between CnB-engaged integrin αM-p38 MAPK signaling and IFN-γ-initiated p38/PKC-δ/Jak2 signaling. Interestingly, the signal transducer and activator of transcription 1 (STAT1) is a key factor that orchestrates the synergy of CnB and IFN-γ, and the phosphorylation status at Ser727 and Tyr701 of STAT1 is directly regulated by CnB and IFN-γ. PMID:25950470

  14. Literature-based discovery of IFN-gamma and vaccine-mediated gene interaction networks.

    PubMed

    Ozgür, Arzucan; Xiang, Zuoshuang; Radev, Dragomir R; He, Yongqun

    2010-01-01

    Interferon-gamma (IFN-gamma) regulates various immune responses that are often critical for vaccine-induced protection. In order to annotate the IFN-gamma-related gene interaction network from a large amount of IFN-gamma research reported in the literature, a literature-based discovery approach was applied with a combination of natural language processing (NLP) and network centrality analysis. The interaction network of human IFN-gamma (Gene symbol: IFNG) and its vaccine-specific subnetwork were automatically extracted using abstracts from all articles in PubMed. Four network centrality metrics were further calculated to rank the genes in the constructed networks. The resulting generic IFNG network contains 1060 genes and 26313 interactions among these genes. The vaccine-specific subnetwork contains 102 genes and 154 interactions. Fifty six genes such as TNF, NFKB1, IL2, IL6, and MAPK8 were ranked among the top 25 by at least one of the centrality methods in one or both networks. Gene enrichment analysis indicated that these genes were classified in various immune mechanisms such as response to extracellular stimulus, lymphocyte activation, and regulation of apoptosis. Literature evidence was manually curated for the IFN-gamma relatedness of 56 genes and vaccine development relatedness for 52 genes. This study also generated many new hypotheses worth further experimental studies. PMID:20625487

  15. Bacterial Muramyl Dipeptide (MDP) Restricts Human Cytomegalovirus Replication via an IFN-β-Dependent Pathway

    PubMed Central

    Kapoor, Arun; Fan, Yi-Hsin; Arav-Boger, Ravit

    2016-01-01

    We recently reported that induction of NOD2 by human Cytomegalovirus (HCMV) resulted in virus inhibition and upregulation of antiviral and inflammatory cytokines. Here we investigated the effects of muramyl dipeptide (MDP), a bacterial cell wall component that activates NOD2, on HCMV replication and antiviral responses. HCMV infection of human foreskin fibroblasts induced NOD2, the downstream receptor-interacting serine/threonine-protein kinase 2 (RIPK2), resulting in phosphorylation of TANK-binding kinase 1 (TBK1) and interferon regulatory factor 3 (IRF3). MDP treatment following infection at low multiplicity (MOI = 0.1 PFU/cell) inhibited HCMV in a dose-dependent manner and further induced phosphorylation of TBK1, IRF3 and expression of IFN-β. None of these effects of MDP were observed following infection at multiplicity of 1. In infected NOD2 knocked-down cells MDP did not induce IFN-β, irrespective of MOI. Treatment with MDP before infection also inhibited HCMV, an effect augmented with treatment duration. Treatment with an IFN-β receptor blocking antibody or knockdown of IFN-β significantly attenuated the inhibitory effect of MDP on HCMV. MDP treatment before or after infection with herpesvirus 1 did not inhibit its replication. Summarized, NOD2 activation exerts anti-HCMV activities predominantly via IFN-β. Since MDP is a bacterial cell wall component, ongoing microbial exposure may influence HCMV replication. PMID:26830977

  16. IL-17/IFN-γ interactions regulate intestinal inflammation in TNBS-induced acute colitis.

    PubMed

    Jin, Yu; Lin, Yan; Lin, Lianjie; Zheng, Changqing

    2012-11-01

    Colonic administration of 2,4,6-trinitrobenzene sulfonic acid (TNBS) induced acute colitis in mice and elicited a Th1 immune response. Th17 cells are believed to play a major role in TNBS-induced colitis. The aim of this study is to investigate the roles of interleukin (IL)-17 and interferon (IFN)-γ in the pathogenesis of TNBS-induced acute colitis. We assessed the inflammation scores of TNBS-induced acute colitis in wild-type (WT), IL-17 knockout (KO), and IFN-γ KO mice and measured the levels of inflammatory cytokines using real-time PCR and ELISAs. Histology data showed that IL-17 KO mice with TNBS-induced colitis had significantly lower neutrophil infiltration and inflammatory macroscopic scores compared to the IFN-γ KO mice and WT mice. Intraperitoneal injection of anti-IL-17 monoclonal antibody confirmed a specific role for IL-17 in TNBS-induced acute colitis in the 3 strains of mice. The severity of colitis was higher in IFN-γ KO mice and lower in IL-17 KO mice compared to WT mice. Our data suggested that IL-17 signaling plays a critical role in the local inflammation of TNBS-induced colitis, while IFN-γ was not an important mediator of the local inflammation response. IL-17 may represent a target for therapeutic intervention in inflammatory bowel disease patients. PMID:23030668

  17. Dengue Virus Control of Type I IFN Responses: A History of Manipulation and Control

    PubMed Central

    Castillo Ramirez, Jorge Andrés

    2015-01-01

    The arthropod-borne diseases caused by dengue virus (DENV) are a major and emerging problem of public health worldwide. Infection with DENV causes a series of clinical manifestations ranging from mild flu syndrome to severe diseases that include hemorrhage and shock. It has been demonstrated that the innate immune response plays a key role in DENV pathogenesis. However, in recent years, it was shown that DENV evades the innate immune response by blocking type I interferon (IFN-I). It has been demonstrated that DENV can inhibit both the production and the signaling of IFN-I. The viral proteins, NS2A and NS3, inhibit IFN-I production by degrading cellular signaling molecules. In addition, the viral proteins, NS2A, NS4A, NS4B, and NS5, can inhibit IFN-I signaling by blocking the phosphorylation of the STAT1 and STAT2 molecules. Finally, NS5 mediates the degradation of STAT2 using the proteasome machinery. In this study, we briefly review the most recent insights regarding the IFN-I response to DENV infection and its implication for pathogenesis. PMID:25629430

  18. IFN-γ induced IDO and WRS expression in microglia is differentially regulated by IL-4

    PubMed Central

    Yadav, Manisha C.; Burudi, E.M.E.; Alirezaei, Mehrdad; Flynn, Claudia C.; Watry, Debbie D.; Lanigan, Caroline M.; Fox, Howard S.

    2008-01-01

    Indoleamine 2,3-dioxygenase (IDO), a tryptophan catabolizing enzyme, has been implicated in the pathogenesis of various neurological disorders. IDO expression is induced by IFN-γ and leads to neurotoxicity by generating quinolinic acid. Additionally, it inhibits the immune response through both tryptophan depletion and generating other tryptophan catabolites. IL-4 and IL-13 have been shown to control IDO expression by antagonizing the effects of IFN-γ in different cell types. Here, we investigated the effects of these cytokines on IDO expression in microglia. Interestingly, we observed that both IL-4 and IL-13 greatly enhanced IFN-γ induced IDO expression. However, tryptophanyl-tRNA synthetase (WRS), which is coinduced with IDO by IFN-γ, is downregulated by IL-4 and IL-13. The effect of IL-4 and IL-13 was independent of STAT-6. Modulation of IDO but not WRS was eliminated by inhibition of protein phosphatase 2A (PP2A) activity. The phosphatidylinositol 3-kinase (PI3K) pathway further differentiated the regulation of these two enzymes, as inhibiting the PI3K pathway eliminated IFN-γ induction of IDO, whereas such inhibition greatly enhanced WRS expression. These findings show discordance between modulations of expression of two distinct enzymes utilizing tryptophan as a common substrate, and raise the possibility of their involvement in regulating immune responses in various neurological disorders. PMID:17661345

  19. Newcastle Disease Virus V Protein Targets Phosphorylated STAT1 to Block IFN-I Signaling

    PubMed Central

    Qiu, Xusheng; Fu, Qiang; Meng, Chunchun; Yu, Shengqing; Zhan, Yuan; Dong, Luna; Song, Cuiping; Sun, Yingjie; Tan, Lei; Hu, Shunlin; Wang, Xiaoquan; Liu, Xiaowen; Peng, Daxin; Liu, Xiufan; Ding, Chan

    2016-01-01

    Newcastle disease virus (NDV) V protein is considered as an effector for IFN antagonism, however, the mechanism remains unknown. In this study, the expression of STAT1 and phospho-STAT1 in cells infected with NDV or transfected with V protein-expressing plasmids were analyzed. Our results showed that NDV V protein targets phospho-STAT1 reduction in the cells depends on the stimulation of IFN-α. In addition, a V-deficient genotype VII recombinant NDV strain rZJ1-VS was constructed using reverse genetic technique to confirm the results. The rZJ1-VS lost the ability to reduce phospho-STAT1 and induced higher expression of IFN-responsive genes in infected cells. Furthermore, treatment with an ubiquitin E1 inhibitor PYR-41 demonstrated that phospho-STAT1 reduction was caused by degradation, but not de-phosphorylation. We conclude that NDV V protein targets phospho-STAT1 degradation to block IFN-α signaling, which adds novel knowledge to the strategies used by paramyxoviruses to evade IFN. PMID:26859759

  20. Mechanism of Interferon-γ–Induced Increase in T84 Intestinal Epithelial Tight Junction

    PubMed Central

    Boivin, Michel A.; Roy, Praveen K.; Bradley, Angela; Kennedy, John C.; Rihani, Tuhama

    2009-01-01

    Interferon-γ (IFN-γ) is an important proinflammatory cytokine that plays a central role in the intestinal inflammatory process of inflammatory bowel disease. IFN-γ induced disturbance of the intestinal epithelial tight junction (TJ) barrier has been postulated to be an important mechanism contributing to intestinal inflammation. The intracellular mechanisms that mediate the IFN-γ induced increase in intestinal TJ permeability remain unclear. The aim of this study was to examine the role of the phosphatidylinositol 3-kinase (PI3-K) pathway in the regulation of the IFN-γ induced increase in intestinal TJ permeability using the T84 intestinal epithelial cell line. IFN-γ caused an increase in T84 intestinal epithelial TJ permeability and depletion of TJ protein, occludin. The IFN-γ induced increase in TJ permeability and alteration in occludin protein was associated with rapid activation of PI3-K; and inhibition of PI3-K activation prevented the IFN-γ induced effects. IFN-γ also caused a delayed but more prolonged activation of nuclear factor-κB (NF-κB); inhibition of NF-κB also prevented the increase in T84 TJ permeability and alteration in occludin expression. The IFN-γ induced activation of NF-κB was mediated by a cross-talk with PI3-K pathway. In conclusion, the IFN-γ induced increase in T84 TJ permeability and alteration in occludin protein expression were mediated by the PI3-K pathway. These results show for the first time that the IFN-γ modulation of TJ protein and TJ barrier function is regulated by a cross-talk between PI3-K and NF-κB pathways. PMID:19128033

  1. Mechanism of interferon-gamma-induced increase in T84 intestinal epithelial tight junction.

    PubMed

    Boivin, Michel A; Roy, Praveen K; Bradley, Angela; Kennedy, John C; Rihani, Tuhama; Ma, Thomas Y

    2009-01-01

    Interferon-gamma (IFN-gamma) is an important proinflammatory cytokine that plays a central role in the intestinal inflammatory process of inflammatory bowel disease. IFN-gamma induced disturbance of the intestinal epithelial tight junction (TJ) barrier has been postulated to be an important mechanism contributing to intestinal inflammation. The intracellular mechanisms that mediate the IFN-gamma induced increase in intestinal TJ permeability remain unclear. The aim of this study was to examine the role of the phosphatidylinositol 3-kinase (PI3-K) pathway in the regulation of the IFN-gamma induced increase in intestinal TJ permeability using the T84 intestinal epithelial cell line. IFN-gamma caused an increase in T84 intestinal epithelial TJ permeability and depletion of TJ protein, occludin. The IFN-gamma induced increase in TJ permeability and alteration in occludin protein was associated with rapid activation of PI3-K; and inhibition of PI3-K activation prevented the IFN-gamma induced effects. IFN-gamma also caused a delayed but more prolonged activation of nuclear factor-kappaB (NF-kappaB); inhibition of NF-kappaB also prevented the increase in T84 TJ permeability and alteration in occludin expression. The IFN-gamma induced activation of NF-kappaB was mediated by a cross-talk with PI3-K pathway. In conclusion, the IFN-gamma induced increase in T84 TJ permeability and alteration in occludin protein expression were mediated by the PI3-K pathway. These results show for the first time that the IFN-gamma modulation of TJ protein and TJ barrier function is regulated by a cross-talk between PI3-K and NF-kappaB pathways. PMID:19128033

  2. IFN-induced Guanylate Binding Proteins in Inflammasome Activation and Host Defense

    PubMed Central

    Kim, Bae-Hoon; Chee, Jonathan D.; Bradfield, Clinton J.; Park, Eui-Soon; Kumar, Pradeep; MacMicking, John D.

    2016-01-01

    Traditional views of the inflammasome highlight pre-existing core components being assembled under basal conditions shortly after infection or tissue damage. Recent work, however, suggests the inflammasome machinery is also subject to tunable or inducible signals that may accelerate its autocatalytic properties and dictate where inflammasome assembly takes place in the cell. Many of these immune signals operate downstream of interferon (IFN) receptors to elicit inflammasome regulators, including a new family of IFN-induced GTPases termed guanylate binding proteins (GBPs). Here, we examine the critical roles for IFN-induced GBPs in directing inflammasome subtype-specific responses and their consequences for cell-autonomous immunity against a wide variety of microbial pathogens. We discuss emerging mechanisms of action and the potential impact of these GBPs on predisposition to sepsis and other infectious or inflammatory diseases. PMID:27092805

  3. Mycobacterial disease and impaired IFN-γ immunity in humans with inherited ISG15 deficiency.

    PubMed

    Bogunovic, Dusan; Byun, Minji; Durfee, Larissa A; Abhyankar, Avinash; Sanal, Ozden; Mansouri, Davood; Salem, Sandra; Radovanovic, Irena; Grant, Audrey V; Adimi, Parisa; Mansouri, Nahal; Okada, Satoshi; Bryant, Vanessa L; Kong, Xiao-Fei; Kreins, Alexandra; Velez, Marcela Moncada; Boisson, Bertrand; Khalilzadeh, Soheila; Ozcelik, Ugur; Darazam, Ilad Alavi; Schoggins, John W; Rice, Charles M; Al-Muhsen, Saleh; Behr, Marcel; Vogt, Guillaume; Puel, Anne; Bustamante, Jacinta; Gros, Philippe; Huibregtse, Jon M; Abel, Laurent; Boisson-Dupuis, Stéphanie; Casanova, Jean-Laurent

    2012-09-28

    ISG15 is an interferon (IFN)-α/β-inducible, ubiquitin-like intracellular protein. Its conjugation to various proteins (ISGylation) contributes to antiviral immunity in mice. Here, we describe human patients with inherited ISG15 deficiency and mycobacterial, but not viral, diseases. The lack of intracellular ISG15 production and protein ISGylation was not associated with cellular susceptibility to any viruses that we tested, consistent with the lack of viral diseases in these patients. By contrast, the lack of mycobacterium-induced ISG15 secretion by leukocytes-granulocyte, in particular-reduced the production of IFN-γ by lymphocytes, including natural killer cells, probably accounting for the enhanced susceptibility to mycobacterial disease. This experiment of nature shows that human ISGylation is largely redundant for antiviral immunity, but that ISG15 plays an essential role as an IFN-γ-inducing secreted molecule for optimal antimycobacterial immunity. PMID:22859821

  4. Mycobacterial disease and impaired IFN-γ immunity in humans with inherited ISG15 deficiency

    PubMed Central

    Bogunovic, Dusan; Byun, Minji; Durfee, Larissa A.; Abhyankar, Avinash; Sanal, Ozden; Mansouri, Davood; Salem, Sandra; Radovanovic, Irena; Grant, Audrey V.; Adimi, Parisa; Mansouri, Nahal; Okada, Satoshi; Bryant, Vanessa L.; Kong, Xiao-Fei; Kreins, Alexandra; Velez, Marcela Moncada; Boisson, Bertrand; Khalilzadeh, Soheila; Ozcelik, Ugur; Darazam, Ilad Alavi; Schoggins, John W.; Rice, Charles M.; Al-Muhsen, Saleh; Behr, Marcel; Vogt, Guillaume; Puel, Anne; Bustamante, Jacinta; Gros, Philippe; Huibregtse, Jon M.; Abel, Laurent; Boisson-Dupuis, Stéphanie; Casanova, Jean-Laurent

    2012-01-01

    ISG15 is an interferon (IFN)-α/β-inducible, ubiquitin-like intracellular protein. Its conjugation to various proteins (ISGylation) contributes to antiviral immunity in mice. We describe human patients with inherited ISG15 deficiency and mycobacterial, but not viral diseases. The lack of intracellular ISG15 production and protein ISGylation was not associated with cellular susceptibility to any viruses tested, consistent with the lack of viral diseases in these patients. By contrast, the lack of mycobacterium-induced ISG15 secretion by leukocytes — granulocytes in particular — reduced the production of IFN-γ by lymphocytes, including natural killer cells, probably accounting for the enhanced susceptibility to mycobacterial disease. This experiment of Nature shows that human ISGylation is largely redundant for antiviral immunity, but that ISG15 plays an essential role as an IFN-γ-inducing secreted molecule for optimal antimycobacterial immunity. PMID:22859821

  5. The antiviral innate immune response in fish: evolution and conservation of the IFN system.

    PubMed

    Langevin, Christelle; Aleksejeva, Elina; Passoni, Gabriella; Palha, Nuno; Levraud, Jean-Pierre; Boudinot, Pierre

    2013-12-13

    Innate immunity constitutes the first line of the host defense after pathogen invasion. Viruses trigger the expression of interferons (IFNs). These master antiviral cytokines induce in turn a large number of interferon-stimulated genes, which possess diverse effector and regulatory functions. The IFN system is conserved in all tetrapods as well as in fishes, but not in tunicates or in the lancelet, suggesting that it originated in early vertebrates. Viral diseases are an important concern of fish aquaculture, which is why fish viruses and antiviral responses have been studied mostly in species of commercial value, such as salmonids. More recently, there has been an interest in the use of more tractable model fish species, notably the zebrafish. Progress in genomics now makes it possible to get a relatively complete image of the genes involved in innate antiviral responses in fish. In this review, by comparing the IFN system between teleosts and mammals, we will focus on its evolution in vertebrates. PMID:24075867

  6. The External Quality Assurance Oversight Laboratory (EQAPOL) Proficiency Program for IFN-gamma Enzyme-Linked ImmunoSpot (IFN-γ ELISpot) assay

    PubMed Central

    Garcia, Ambrosia; Schuetz, Alexandra; Cox, Josephine; Frahm, Nicole; Manak, Mark; Sarzotti-Kelsoe, Marcella; D'Souza, M. Patricia; Denny, Thomas; Ferrari, Guido

    2014-01-01

    The Interferon-gamma Enzyme-Linked ImmunoSpot (IFN-γ ELISpot) assay has been developed and used as an end-point assay in clinical trials for infectious diseases and cancer to detect the magnitude of antigen-specific immune responses. The ability to compare data generated by different laboratories across organizations is pivotal to understand the relative potency of different therapeutic and vaccine strategies. We developed an external proficiency program for the IFN-γ ELISpot assay that evaluates the laboratory performance based on five parameters: timeliness for data reporting; ability to handle cellular samples; detection of background (non-specific) responses; accuracy to consensus of the results; and precision of the measurements. Points are awarded for each criterion, and the sum of the points is used to determine a numeric and adjectival performance rating. Importantly, the evaluation of the accuracy to the consensus mean for the detection of antigen-specific responses using laboratory-specific procedures informs each laboratory and its sponsor on the degree of concordance of its results with those obtained by other laboratories. This study will ultimately provide the scientific community with information on how to organize and implement an external proficiency program to evaluate longitudinally the performance of the participating laboratories and, therefore, fulfill the requirements of the GCLP guidelines for laboratories performing end-point IFN-γ ELISpot assay for clinical trials. PMID:24685833

  7. Evolution of IFN-λ in tetrapod vertebrates and its functional characterization in green anole lizard (Anolis carolinensis).

    PubMed

    Chen, Shan Nan; Zhang, Xiao Wen; Li, Li; Ruan, Bai Ye; Huang, Bei; Huang, Wen Shu; Zou, Peng Fei; Fu, Jian Ping; Zhao, Li Juan; Li, Nan; Nie, Pin

    2016-08-01

    IFN-λ (IFNL), i.e. type III IFN genes were found in a conserved gene locus in tetrapod vertebrates. But, a unique locus containing IFNL was found in avian. In turtle and crocodile, IFNL genes were distributed in these two separate loci. As revealed in phylogenetic trees, IFN-λs in these two different loci and other amniotes were grouped into two different clades. The conservation in gene presence and gene locus was also observed for the receptors of IFN-λ, IFN-λR1 and IL-10RB in tetrapods. It is further revealed that in North American green anole lizard Anolis carolinensis, a single IFNL gene was situated collinearly in the conserved locus as in other tetrapods, together with its receptors IFN-λR1 and IL-10RB also identified in this study. The IFN-λ and its receptors were expressed in all examined organs/tissues, and their expression was stimulated following the injection of polyI:polyC. The ISREs in promoter of IFN-λ in lizard were responsible to IRF3 as demonstrated using luciferase report system, and IFN-λ in lizard functioned through the receptors, IFN-λR1 and IL-10RB, as the up-regulation of ISGs was observed in ligand-receptor transfected, and also in recombinant IFN-λ stimulated, cell lines. Taken together, it is concluded that the mechanisms involved in type III IFN ligand-receptor system, and in its signalling pathway and its down-stream genes may be conserved in green anole lizard, and may even be so in tetrapods from xenopus to human. PMID:27062970

  8. [Effects of IFN-γ treatment on biological characteristics and functions of dendritic cells].

    PubMed

    Liu, Yanling; Wang, Hongmei; Yu, Yanrong; Yuan, Keng; Zhang, Yujuan; Min, Weiping

    2016-08-01

    Objective To investigate the effect of IFN-γ treatment on the biological characteristics and functions of C57BL/6 murine dendritic cells (DCs). Methods In the process of DC culture, 20 ng/mL IFN-γ was added in the DCs at the early (day 2) or late (day 5) stage, and on day 7, LPS was added to stimulate DC maturation. The expressions of DC surface molecules CD11c, CD80 and CD86 were determined by flow cytometry. To analyze cell functions, DCs were co-cultured with BALB/c mouse-derived lymphocyte cells. The 5, 6-carboxyfluorescein diacetate N-succinimidyl ester (CFSE) labelling was used to detect their ability to stimulate allogeneic lymphocyte proliferation and flow cytometry was used to measure their ability to induce the production of regulatory T cells (Tregs). Results Compared with the control group, the early IFN-γ treatment group had decreased DC number and inhibited cell differentiation; though there was no difference in the expression of co-stimulatory molecules, early IFN-γ treatment resisted the stimulatory effect of LPS on DC maturation, weakened the ability to stimulate allogeneic lymphocyte proliferation and enhanced the ability to induce more Tregs. Compared with the control group, the late IFN-γ treatment group showed no change in DC number and differentiation; the expressions of co-stimulatory molecules CD86 and CD80 were upregulated; the results of DC maturation and mixed allogeneic lymphocyte reaction stimulated by LPS were similar to those in the control group, but its ability to induce Tregs was stronger. Conclusion DCs treated with IFN-γ at early stage and those at late stage showed obvious difference in biological characteristics and functions. PMID:27412927

  9. Mining of vaccine-associated IFN-γ gene interaction networks using the Vaccine Ontology

    PubMed Central

    2011-01-01

    Background Interferon-gamma (IFN-γ) is vital in vaccine-induced immune defense against bacterial and viral infections and tumor. Our recent study demonstrated the power of a literature-based discovery method in extraction and comparison of the IFN-γ and vaccine-mediated gene interaction networks. The Vaccine Ontology (VO) contains a hierarchy of vaccine names. It is hypothesized that the application of VO will enhance the prediction of IFN-γ and vaccine-mediated gene interaction network. Results In this study, 186 specific vaccine names listed in the Vaccine Ontology (VO) and their semantic relations were used for possible improved retrieval of the IFN-γ and vaccine associated gene interactions. The application of VO allows discovery of 38 more genes and 60 more interactions. Comparison of different layers of IFN-γ networks and the example BCG vaccine-induced subnetwork led to generation of new hypotheses. By analyzing all discovered genes using centrality metrics, 32 genes were ranked high in the VO-based IFN-γ vaccine network using four centrality scores. Furthermore, 28 specific vaccines were found to be associated with these top 32 genes. These specific vaccine-gene associations were further used to generate a network of vaccine-vaccine associations. The BCG and LVS vaccines are found to be the most central vaccines in the vaccine-vaccine association network. Conclusion Our results demonstrate that the combined usages of biomedical ontologies and centrality-based literature mining are able to significantly facilitate discovery of gene interaction networks and gene-concept associations. Availability VO is available at: http://www.violinet.org/vaccineontology; and the SVM edit kernel for gene interaction extraction is available at: http://www.violinet.org/ifngvonet/int_ext_svm.zip PMID:21624163

  10. Contribution of Thy1+ NK cells to protective IFN-γ production during Salmonella Typhimurium infections

    PubMed Central

    Kupz, Andreas; Scott, Timothy A.; Belz, Gabrielle T.; Andrews, Daniel M.; Greyer, Marie; Lew, Andrew M.; Brooks, Andrew G.; Smyth, Mark J.; Curtiss, Roy; Bedoui, Sammy; Strugnell, Richard A.

    2013-01-01

    IFN-γ is critical for immunity against infections with intracellular pathogens, such as Salmonella enterica. However, which of the many cell types capable of producing IFN-γ controls Salmonella infections remains unclear. Using a mouse model of systemic Salmonella infection, we observed that only a lack of all lymphocytes or CD90 (Thy1)+ cells, but not the absence of T cells, Retinoic acid-related orphan receptor (ROR)-γt–dependent lymphocytes, (NK)1.1+ cells, natural killer T (NKT), and/or B cells alone, replicated the highly susceptible phenotype of IFN-γ–deficient mice to Salmonella infection. A combination of antibody depletions and adoptive transfer experiments revealed that early protective IFN-γ was provided by Thy1-expressing natural killer (NK) cells and that these cells improved antibacterial immunity through the provision of IFN-γ. Further analysis of NK cells producing IFN-γ in response to Salmonella indicated that less mature NK cells were more efficient at mediating antibacterial effector function than terminally differentiated NK cells. Inspired by recent reports of Thy1+ NK cells contributing to immune memory, we analyzed their role in secondary protection against otherwise lethal WT Salmonella infections. Notably, we observed that a newly generated Salmonella vaccine strain not only conferred superior protection compared with conventional regimens but that this enhanced efficiency of recall immunity was afforded by incorporating CD4−CD8−Thy1+ cells into the secondary response. Taken together, these findings demonstrate that Thy1-expressing NK cells play an important role in antibacterial immunity. PMID:23345426

  11. Increased epidermal growth factor receptor gene expression by gamma-interferon in a human breast carcinoma cell line.

    PubMed Central

    Hamburger, A. W.; Pinnamaneni, G. D.

    1991-01-01

    The interferons are a group of naturally occurring proteins that inhibit the growth of tumours in vivo and many transformed cell lines in vitro. The mechanisms of action of interferon, however, remain unclear. The IFN induced inhibition of growth of many epithelial cancer cell lines is associated with changes in Epidermal Growth Factor Receptor (EGFR) binding or expression. Therefore, we examined the effect of IFN treatment on the expression of EGFR in a human breast carcinoma cell line, MDA 468. We have found the IFN-gamma inhibited, in a dose dependent fashion, the growth of MDA 468 cells. IFN decreased cell surface binding of 125I-EGF to EGFR by changing receptor number rather than affinity. However, total cellular receptor protein, as measured by immunoprecipitation with monoclonal antibodies, was increased in IFN-treated cells. The half-life of the metabolically labelled receptor was unchanged by treatment with IFN. Increased amounts of EGFR mRNA were observed in MDA 468 cells treated with IFN-gamma for 3 days. The levels of mRNA increased with time in culture, reaching a peak of four times control values after 5 days of treatment. This effect was observable with as little as 10 U ml-1 of IFN-gamma. Treatment of the cells with Actinomycin D to inhibit new RNA synthesis suggested that the stability of EGFR mRNA was not enhanced in IFN-gamma treated cells. The increase in receptor mRNA induced by IFN was not inhibited by cycloheximide. These data suggest IFN-gamma can increase expression of EGFR mRNA and protein in MDA 468 cells. Increased expression of EGFR mRNA and protein by IFN-gamma is associated with inhibition of cell growth. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 PMID:1906727

  12. FcγRIIB prevents inflammatory type I IFN production from plasmacytoid dendritic cells during a viral memory response.

    PubMed

    Flores, Marcella; Chew, Claude; Tyan, Kevin; Huang, Wu Qing; Salem, Aliasger; Clynes, Raphael

    2015-05-01

    The type I IFN (IFN-α) response is crucial for viral clearance during primary viral infections. Plasmacytoid dendritic cells (pDCs) are important early responders during systemic viral infections and, in some cases, are the sole producers of IFN-α. However, their role in IFN-α production during memory responses is unclear. We found that IFN-α production is absent during a murine viral memory response, despite colocalization of virus and pDCs to the splenic marginal zone. The absence of IFN was dependent on circulating Ab and was reversed by the transgenic expression of the activating human FcγRIIA receptor on pDCs. Furthermore, FcγRIIB was required for Sendai virus immune complex uptake by splenic pDCs in vitro, and internalization via FcγRIIb prevented cargo from accessing TLR signaling endosomes. Thus, pDCs bind viral immune complexes via FcγRIIB and prevent IFN-α production in vivo during viral memory responses. This Ab-dependent IFN-α regulation may be an important mechanism by which the potentially deleterious effects of IFN-α are prevented during a secondary infection. PMID:25821224

  13. Cutting Edge: IFN-γ Produced by Brain-Resident Cells Is Crucial To Control Cerebral Infection with Toxoplasma gondii.

    PubMed

    Sa, Qila; Ochiai, Eri; Tiwari, Ashish; Perkins, Sara; Mullins, Jeremi; Gehman, Marie; Huckle, William; Eyestone, Willard H; Saunders, Thomas L; Shelton, Brent J; Suzuki, Yasuhiro

    2015-08-01

    In vitro studies demonstrated that microglia and astrocytes produce IFN-γ in response to various stimulations, including LPS. However, the physiological role of IFN-γ production by brain-resident cells, including glial cells, in resistance against cerebral infections remains unknown. We analyzed the role of IFN-γ production by brain-resident cells in resistance to reactivation of cerebral infection with Toxoplasma gondii using a murine model. Our study using bone marrow chimeric mice revealed that IFN-γ production by brain-resident cells is essential for upregulating IFN-γ-mediated protective innate immune responses to restrict cerebral T. gondii growth. Studies using a transgenic strain that expresses IFN-γ only in CD11b(+) cells suggested that IFN-γ production by microglia, which is the only CD11b(+) cell population among brain-resident cells, is able to suppress the parasite growth. Furthermore, IFN-γ produced by brain-resident cells is pivotal for recruiting T cells into the brain to control the infection. These results indicate that IFN-γ produced by brain-resident cells is crucial for facilitating both the protective innate and T cell-mediated immune responses to control cerebral infection with T. gondii. PMID:26091720

  14. Direct stimulation of T cells by type I IFN enhances the CD8+ T cell response during cross-priming.

    PubMed

    Le Bon, Agnes; Durand, Vanessa; Kamphuis, Elisabeth; Thompson, Clare; Bulfone-Paus, Silvia; Rossmann, Cornelia; Kalinke, Ulrich; Tough, David F

    2006-04-15

    Type I IFN (IFN-alphabeta), which is produced rapidly in response to infection, plays a key role in innate immunity and also acts as a stimulus for the adaptive immune response. We have investigated how IFN-alphabeta induces cross-priming, comparing CD8+ T cell responses generated against soluble protein Ags in the presence or absence of IFN-alphabeta. Injection of IFN-alpha was found to prolong the proliferation and expansion of Ag-specific CD8+ T cells, which was associated with marked up-regulation of IL-2 and IL-15 receptors on Ag-specific cells and expression of IL-15 in the draining lymph node. Surprisingly, neither IL-2 nor IL-15 was required for IFN-alpha-induced cross-priming. Conversely, expression of the IFN-alphabetaR by T cells was shown to be necessary for effective stimulation of the response by IFN-alpha. The finding that T cells represent direct targets of IFN-alphabeta-mediated stimulation reveals an additional mechanism by which the innate response to infection promotes adaptive immunity. PMID:16585561

  15. Tumor-induced myeloid-derived suppressor cell function is independent of IFN-γ and IL-4Rα.

    PubMed

    Sinha, Pratima; Parker, Katherine H; Horn, Lucas; Ostrand-Rosenberg, Suzanne

    2012-08-01

    Myeloid-derived suppressor cells (MDSCs) are present in most cancer patients and experimental animals where they exert a profound immune suppression and are a significant obstacle to immunotherapy. IFN-γ and IL-4 receptor alpha (IL-4Rα) have been implicated as essential molecules for MDSC development and immunosuppressive function. If IFN-γ and IL-4Rα are critical regulators of MDSCs, then they are potential targets for preventing MDSC accumulation or inhibiting MDSC function. Because data supporting a role for IFN-γ and IL-4Rα are not definitive, we have examined MDSCs induced in IFN-γ-deficient, IFN-γR-deficient, and IL-4Rα-deficient mice carrying three C57BL/6-derived (B16 melanoma, MC38 colon carcinoma, and 3LL lung adenocarcinoma), and three BALB/c-derived (4T1 and TS/A mammary carcinomas, and CT26 colon carcinoma) tumors. We report that although MDSCs express functional IFN-γR and IL-4Rα, and have the potential to signal through the STAT1 and STAT6 pathways, respectively, neither IFN-γ nor IL-4Rα impacts the phenotype, accumulation, or T-cell suppressive potency of MDSCs, although IFN-γ and IL-4Rα modestly alter MDSC-macrophage IL-10 crosstalk. Therefore, neither IFN-γ nor IL-4Rα is a key regulator of MDSCs and targeting these molecules is unlikely to significantly alter MDSC accumulation or function. PMID:22673957

  16. Depletion of IFN-gamma, CD8+ or Tcr gamma delta+ cells in vivo during primary infection with an enteric parasite (Trichostrongylus colubriformis) enhances protective immunity.

    PubMed

    McClure, S J; Davey, R J; Lloyd, J B; Emery, D L

    1995-12-01

    In order to examine the role of CD8+ and WCI+ T cells and of IFN-gamma in the development of protective immunity against infection with the enteric nematode parasite Trichostrongylus colubriformis in sheep, mAb were administered during induction of the immune response to deplete or neutralize these components. Protection against the primary and challenge infections were assessed by faecal egg count and total worm count. Prolonged administration of mAb recognizing IFN-gamma and CD8+ resulted in significantly increased protection during the 6-week primary infection. CD8+ cells were depleted from blood but not intestinal mucosa. After injection of mAb (CC15) recognizing the surface antigen WCI, WCI+ and T cell receptor (Tcr) gamma delta+ cells were depleted from blood but not from enteric mucosa, and protection against challenge, although variable, was increased by up to 88%. It appears that CD8+ and WCI+/gamma delta+ cells and IFN-gamma all retard the potential development of naturally-acquired immunity against the parasite. PMID:8713478

  17. Rapid activation of spleen dendritic cell subsets following lymphocytic choriomeningitis virus infection of mice: analysis of the involvement of type 1 IFN.

    PubMed

    Montoya, Maria; Edwards, Matthew J; Reid, Delyth M; Borrow, Persephone

    2005-02-15

    In this study, we report the dynamic changes in activation and functions that occur in spleen dendritic cell (sDC) subsets following infection of mice with a natural murine pathogen, lymphocytic choriomeningitis virus (LCMV). Within 24 h postinfection (pi), sDCs acquired the ability to stimulate naive LCMV-specific CD8+ T cells ex vivo. Conventional (CD11chigh CD8+ and CD4+) sDC subsets rapidly up-regulated expression of costimulatory molecules and began to produce proinflammatory cytokines. Their tendency to undergo apoptosis ex vivo simultaneously increased, and in vivo the number of conventional DCs in the spleen decreased markedly, dropping approximately 2-fold by day 3 pi. Conversely, the number of plasmacytoid (CD11clowB220+) DCs in the spleen increased, so that they constituted almost 40% of sDCs by day 3 pi. Type 1 IFN production was up-regulated in plasmacytoid DCs by 24 h pi. Analysis of DC activation and maturation in mice unable to respond to type 1 IFNs implicated these cytokines in driving infection-associated phenotypic activation of conventional DCs and their enhanced tendency to undergo apoptosis, but also indicated the existence of type 1 IFN-independent pathways for the functional maturation of DCs during LCMV infection. PMID:15699111

  18. Leptin potentiates IFN-γ-induced expression of nitric oxide synthase and cyclo-oxygenase-2 in murine macrophage J774A.1

    PubMed Central

    Raso, Giuseppina Mattace; Pacilio, Maria; Esposito, Emanuela; Coppola, Anna; Di Carlo, Raffaele; Meli, Rosaria

    2002-01-01

    Leptin, a pleiotropic hormone believed to regulate body weight, has recently been associated with inflammatory states and immune activity. Here we have studied the effect of leptin on expression of IFN-γ-induced nitric oxide synthase (iNOS) and cyclo-oxygenase-2 (COX-2), both prominent markers of macrophage activation, using the murine macrophage J774A.1 cell line. After 24 h of incubation, leptin (1–10 μg ml−1) potently synergized with IFN-γ (100 U ml−1) in nitric oxide (NO) release, evaluated as nitrite and nitrate (NOx), and prostaglandin E2 (PGE2) production in culture medium. The observed increase of NO and PGE2 was related to enhanced expression of the respective inducible enzyme isoforms, measured in mRNA and protein by RT–PCR and Western blot analysis, respectively. When cells were stimulated only with leptin, a weak induction of NO and PGE2 release and of the expression of related inducible enzymes was observed. Moreover IFNincreased the expression of the functional form of leptin receptor (Ob-Rb) and this effect was potentiated by leptin in a concentration-dependent manner. These data suggest that macrophages, among the peripheral immune cells, represent a target for leptin and confirm the relevance of this hormone in the pathophysiology of inflammation. PMID:12411410

  19. Lion (Panthera leo) and cheetah (Acinonyx jubatus) IFN-gamma sequences.

    PubMed

    Maas, Miriam; Van Rhijn, Ildiko; Allsopp, Maria T E P; Rutten, Victor P M G

    2010-04-15

    Cloning and sequencing of the full length lion and cheetah interferon-gamma (IFN-gamma) transcript will enable the expression of the recombinant cytokine, to be used for production of monoclonal antibodies and to set up lion and cheetah-specific IFN-gamma ELISAs. These are relevant in blood-based diagnosis of bovine tuberculosis, an important threat to lions in the Kruger National Park. Alignment of nucleotide and amino acid sequences of lion and cheetah and that of domestic cats showed homologies of 97-100%. PMID:19913304

  20. A20 Regulates Atherogenic Interferon (IFN)-γ Signaling in Vascular Cells by Modulating Basal IFNβ Levels*

    PubMed Central

    Moll, Herwig P.; Lee, Andy; Minussi, Darlan C.; da Silva, Cleide G.; Csizmadia, Eva; Bhasin, Manoj; Ferran, Christiane

    2014-01-01

    IFNγ signaling in endothelial (EC) and smooth muscle cells (SMC) is a key culprit of pathologic vascular remodeling. The impact of NF-κB inhibitory protein A20 on IFNγ signaling in vascular cells remains unknown. In gain- and loss-of-function studies, A20 inversely regulated expression of IFNγ-induced atherogenic genes in human EC and SMC by modulating STAT1 transcription. In vivo, inadequate A20 expression in A20 heterozygote mice aggravated intimal hyperplasia following partial carotid artery ligation. This outcome uniquely associated with increased levels of Stat1 and super-induction of Ifnγ-dependent genes. Transcriptome analysis of the aortic media from A20 heterozygote versus wild-type mice revealed increased basal Ifnβ signaling as the likely cause for higher Stat1 transcription. We confirmed higher basal IFNβ levels in A20-silenced human SMC and showed that neutralization or knockdown of IFNβ abrogates heightened STAT1 levels in these cells. Upstream of IFNβ, A20-silenced EC and SMC demonstrated higher levels of phosphorylated/activated TANK-binding kinase-1 (TBK1), a regulator of IFNβ transcription. This suggested that A20 knockdown increased STAT1 transcription by enhancing TBK1 activation and subsequently basal IFNβ levels. Altogether, these results uncover A20 as a key physiologic regulator of atherogenic IFNγ/STAT1 signaling. This novel function of A20 added to its ability to inhibit nuclear factor-κB (NF-κB) activation solidifies its promise as an ideal therapeutic candidate for treatment and prevention of vascular diseases. In light of recently discovered A20/TNFAIP3 (TNFα-induced protein 3) single nucleotide polymorphisms that impart lower A20 expression or function, these results also qualify A20 as a reliable clinical biomarker for vascular risk assessment. PMID:25217635

  1. PEG-IFN Alpha but Not Ribavirin Alters NK Cell Phenotype and Function in Patients with Chronic Hepatitis C

    PubMed Central

    Markova, Antoaneta A.; Mihm, Ulrike; Schlaphoff, Verena; Lunemann, Sebastian; Filmann, Natalie; Bremer, Birgit; Berg, Thomas; Sarrazin, Christoph; Zeuzem, Stefan; Manns, Michael P.; Cornberg, Markus; Herrmann, Eva; Wedemeyer, Heiner

    2014-01-01

    Background Ribavirin (RBV) remains part of several interferon-free treatment strategies even though its mechanisms of action are still not fully understood. One hypothesis is that RBV increases responsiveness to type I interferons. Pegylated Interferon alpha (PEG-IFNa) has recently been shown to alter natural killer (NK) cell function possibly contributing to control of hepatitis C virus (HCV) infection. However, the effects of ribavirin alone or in combination with IFNa on NK cells are unknown. Methods Extensive ex vivo phenotyping and functional analysis of NK cells from hepatitis C patients was performed during antiviral therapy. Patients were treated for 6 weeks with RBV monotherapy (n = 11), placebo (n = 13) or PEG-IFNa-2a alone (n = 6) followed by PEG-IFNa/RBV combination therapy. The effects of RBV and PEG-IFNa-2a on NK cells were also studied in vitro after co-culture with K562 or Huh7.5 cells. Results Ribavirin monotherapy had no obvious effects on NK cell phenotype or function, neither ex vivo in patients nor in vitro. In contrast, PEG-IFNa-2a therapy was associated with an increase of CD56bright cells and distinct changes in expression profiles leading to an activated NK cell phenotype, increased functionality and decline of terminally differentiated NK cells. Ribavirin combination therapy reduced some of the IFN effects. An activated NK cell phenotype during therapy was inversely correlated with HCV viral load. Conclusions PEG-IFNa activates NK cells possibly contributing to virological responses independently of RBV. The role of NK cells during future IFN-free combination therapies including RBV remains to be determined. PMID:24751903

  2. Phenotypic and functional characteristics of active suppressor cells against IFN-gamma production in PHA-stimulated cord blood lymphocytes

    SciTech Connect

    Seki, H.; Taga, K.; Matsuda, A.; Uwadana, N.; Hasui, M.; Miyawaki, T.; Taniguchi, N.

    1986-11-15

    Cord blood mononuclear cells (MNC) were defective in their ability to produce interferon-gamma (IFN-gamma) on stimulation with phytohemagglutinin (PHA) or recombinant interleukin 2, whereas cord MNC could induce comparable amounts of IFN-gamma with adult controls on stimulation with a streptococcal preparation, OK-432. Moreover, irradiation of cord MNC with 1500 rad before PHA stimulation could restore the IFN-gamma production. Kinetic studies indicated that such augmentation of IFN-gamma production by irradiation was evident when cord MNC were irradiated before or by 12 hr of PHA-stimulated culture. But irradiation after 18 hr or more of PHA stimulation did not exert any significant augmentation on IFN-gamma production by cord MNC. It seemed most likely that the ability of IFN-gamma production is already mature at birth, but radiosensitive suppressor effectors on IFN-gamma production are activated within cord MNC at an early stage of PHA stimulation, resulting in poor IFN-gamma production by cord MNC. PHA-induced IFN-gamma production by OKT3+, OKT4+, and OKT8- cord cells were markedly enhanced by irradiation with 1,500 rad before the culture. Coculture experiments disclosed that cord OKT4+ cells, but not OKT4- cells, when prestimulated with PHA for 24 hr, exerted active suppression on PHA-induced IFN-gamma production by adult MNC in a dose-dependent manner. These results suggested that radiosensitive suppressor effectors on IFN-gamma production were induced within the OKT4+ T cell subset of cord MNC on PHA stimulation.

  3. Type I IFN Induces IL-10 Production in an IL-27–Independent Manner and Blocks Responsiveness to IFN-γ for Production of IL-12 and Bacterial Killing in Mycobacterium tuberculosis–Infected Macrophages

    PubMed Central

    Ewbank, John; Howes, Ashleigh; Moreira-Teixeira, Lucia; Martirosyan, Anna; Ghilardi, Nico; Saraiva, Margarida; O’Garra, Anne

    2014-01-01

    Tuberculosis, caused by the intracellular bacterium Mycobacterium tuberculosis, currently causes ∼1.4 million deaths per year, and it therefore remains a leading global health problem. The immune response during tuberculosis remains incompletely understood, particularly regarding immune factors that are harmful rather than protective to the host. Overproduction of the type I IFN family of cytokines is associated with exacerbated tuberculosis in both mouse models and in humans, although the mechanisms by which type I IFN promotes disease are not well understood. We have investigated the effect of type I IFN on M. tuberculosis–infected macrophages and found that production of host-protective cytokines such as TNF-α, IL-12, and IL-1β is inhibited by exogenous type I IFN, whereas production of immunosuppressive IL-10 is promoted in an IL-27–independent manner. Furthermore, much of the ability of type I IFN to inhibit cytokine production was mediated by IL-10. Additionally, type I IFN compromised macrophage activation by the lymphoid immune response through severely disrupting responsiveness to IFN-γ, including M. tuberculosis killing. These findings describe important mechanisms by which type I IFN inhibits the immune response during tuberculosis. PMID:25187652

  4. Type I IFN induces IL-10 production in an IL-27-independent manner and blocks responsiveness to IFN-γ for production of IL-12 and bacterial killing in Mycobacterium tuberculosis-infected macrophages.

    PubMed

    McNab, Finlay W; Ewbank, John; Howes, Ashleigh; Moreira-Teixeira, Lucia; Martirosyan, Anna; Ghilardi, Nico; Saraiva, Margarida; O'Garra, Anne

    2014-10-01

    Tuberculosis, caused by the intracellular bacterium Mycobacterium tuberculosis, currently causes ∼1.4 million deaths per year, and it therefore remains a leading global health problem. The immune response during tuberculosis remains incompletely understood, particularly regarding immune factors that are harmful rather than protective to the host. Overproduction of the type I IFN family of cytokines is associated with exacerbated tuberculosis in both mouse models and in humans, although the mechanisms by which type I IFN promotes disease are not well understood. We have investigated the effect of type I IFN on M. tuberculosis-infected macrophages and found that production of host-protective cytokines such as TNF-α, IL-12, and IL-1β is inhibited by exogenous type I IFN, whereas production of immunosuppressive IL-10 is promoted in an IL-27-independent manner. Furthermore, much of the ability of type I IFN to inhibit cytokine production was mediated by IL-10. Additionally, type I IFN compromised macrophage activation by the lymphoid immune response through severely disrupting responsiveness to IFN-γ, including M. tuberculosis killing. These findings describe important mechanisms by which type I IFN inhibits the immune response during tuberculosis. PMID:25187652

  5. [Growth inhibition of melanoma cells by interferons in vitro. Similar antiproliferative effects of 100-1000 times lower concentrations of nIFN-beta in comparison with rIFN-alpha-2a].

    PubMed

    Zouboulis, C; Garbe, C; Orfanos, C E

    1989-02-01

    The type I interferons (IFNs) rIFN-alpha 2a and nIFN-beta showed a significant dose-dependent antiproliferative effect on melanoma cell monolayer cultures in vitro compared with untreated controls (P less than 0.01 at 10 IU/ml; P less than 0.01 and P less than 0.001 at 1,000 IU/ml). The antiproliferative effect of a single IFN dose lasted for a maximum of 4 days, after which uninhibited proliferation of melanoma cells was again observed. In all experiments nIFN-beta showed a similar antiproliferative effect to rIFN-alpha 2a on the two melanoma cell lines (StML-11, SKMel-28) tested, when used in concentrations 100-1,000 times lower. At concentrations of 10,000 IU/ml rIFN-alpha 2a and 100-1,000 IU/ml hIFN-beta cytotoxic effects were observed. PMID:2714987

  6. THE E3 UBIQUITIN LIGASE RO52 NEGATIVELY REGULATES IFN-β PRODUCTION POST-PATHOGEN RECOGNITION BY POLYUBIQUITIN-MEDIATED DEGRADATION OF IRF31

    PubMed Central

    Higgs, Rowan; Gabhann, Joan Ní; Larbi, Nadia Ben; Breen, Eamon P.; Fitzgerald, Katherine A.; Jefferies, Caroline A.

    2010-01-01

    Induction of type I interferons is a fundamental cellular response to both viral and bacterial infection. The role of the transcription factor IRF3 is well established in driving this process. However, equally as important are cellular mechanisms for turning off type I interferon production in order to limit this response. In this respect, IRF3 has previously been shown to be targeted for ubiquitin-mediated degradation post-viral detection in order to turn off the IFN-β response. Here we provide evidence that the E3 ligase Ro52 (TRIM21) targets IRF3 for degradation post-pathogen recognition receptor activation. We demonstrate that Ro52 interacts with IRF3 via its C-terminal SPRY domain, resulting in the polyubiquitination and proteasomal degradation of the transcription factor. Ro52-mediated IRF3 degradation significantly inhibits IFN-β promoter activity, an effect that is reversed in the presence of the proteasomal inhibitor MG132. Specific targeting of Ro52 using shRNA rescues IRF3 degradation following polyI:C-stimulation of HEK293T cells, with a subsequent increase in IFN-β production. Additionally, shRNA targeting of murine Ro52 enhances the production of the IRF3-dependent chemokine RANTES following Sendai virus infection of murine fibroblasts. Collectively, this demonstrates a novel role for Ro52 in turning off and thus limiting IRF3-dependent type I interferon production by targeting the transcription factor for polyubiquitination and subsequent proteasomal degradation. PMID:18641315

  7. Differential Co-Expression between α-Synuclein and IFN-γ Signaling Genes across Development and in Parkinson’s Disease

    PubMed Central

    Liscovitch, Noa; French, Leon

    2014-01-01

    Expression patterns of the alpha-synuclein gene (SNCA) were studied across anatomy, development, and disease to better characterize its role in the brain. In this postmortem study, negative spatial co-expression between SNCA and 73 interferon-γ (IFN-γ) signaling genes was observed across many brain regions. Recent animal studies have demonstrated that IFN-γ induces loss of dopamine neurons and nigrostriatal degeneration. This opposing pattern between SNCA and IFN-γ signaling genes increases with age (rho = −0.78). In contrast, a meta-analysis of four microarray experiments representing 126 substantia nigra samples reveals a switch to positive co-expression in Parkinson’s disease (p<0.005). Use of genome-wide testing demonstrates this relationship is specific to SNCA (p<0.002). This change in co-expression suggests an immunomodulatory role of SNCA that may provide insight into neurodegeneration. Genes showing similar co-expression patterns have been previously linked to Alzheimer’s (ANK1) and Parkinson’s disease (UBE2E2, PCMT1, HPRT1 and RIT2). PMID:25493648

  8. TLR3/TRIF signalling pathway regulates IL-32 and IFN-β secretion through activation of RIP-1 and TRAF in the human cornea

    PubMed Central

    Park, Ga Bin; Hur, Dae Young; Kim, Yeong Seok; Lee, Hyun-Kyung; Yang, Jae Wook; Kim, Daejin

    2015-01-01

    Toll-like receptor-3 (TLR3) and RNA helicase retinoic-acid-inducible protein-1 (RIG-I) serve as cytoplasmic sensors for viral RNA components. In this study, we investigated how the TLR3 and RIG-I signalling pathway was stimulated by viral infection to produce interleukin (IL)-32-mediated pro-inflammatory cytokines and type I interferon in the corneal epithelium using Epstein–Barr virus (EBV)-infected human cornea epithelial cells (HCECs/EBV) as a model of viral keratitis. Increased TLR3 and RIG-I that are responded to EBV-encoded RNA 1 and 2 (EBER1 and EBER2) induced the secretion of IL-32-mediated pro-inflammatory cytokines and IFN-β through up-regulation of TRIF/TRAF family proteins or RIP-1. TRIF silencing or TLR3 inhibitors more efficiently inhibited sequential phosphorylation of TAK1, TBK1, NF-κB and IRFs to produce pro-inflammatory cytokines and IFN-β than RIG-I-siRNA transfection in HCECs/EBV. Blockade of RIP-1, which connects the TLR3 and RIG-I pathways, significantly blocked the TLR3/TRIF-mediated and RIG-I-mediated pro-inflammatory cytokines and IFN-β production in HCECs/EBV. These findings demonstrate that TLR3/TRIF-dependent signalling pathway against viral RNA might be a main target to control inflammation and anti-viral responses in the ocular surface. PMID:25754842

  9. Antigen-Specific Mammary Inflammation Depends on the Production of IL-17A and IFN-γ by Bovine CD4+ T Lymphocytes

    PubMed Central

    Rainard, Pascal; Cunha, Patricia; Ledresseur, Marion; Staub, Christophe; Touzé, Jean-Luc; Kempf, Florent; Gilbert, Florence B.; Foucras, Gilles

    2015-01-01

    Intramammary infusion of the antigen used to sensitize cows by the systemic route induces a local inflammation associated with neutrophil recruitment. We hypothesize that this form of delayed type hypersensitivity, which may occur naturally during infections or could be induced intentionally by vaccination, can impact the outcome of mammary gland infections. We immunized cows with ovalbumin to identify immunological correlates of antigen-specific mammary inflammation. Intraluminal injection of ovalbumin induced a mastitis characterized by a prompt tissue reaction (increase in teat wall thickness) and an intense influx of leukocytes into milk of 10 responder cows out of 14 immunized animals. The magnitude of the local inflammatory reaction, assessed through milk leukocytosis, correlated with antibody titers, skin thickness test, and production of IL-17A and IFN-γ in a whole-blood antigen stimulation assay (WBA). The production of these two cytokines significantly correlated with the magnitude of the milk leukocytosis following the ovalbumin intramammary challenge. The IL-17A and IFN-γ production in the WBA was dependent on the presence of CD4+ cells in blood samples. In vitro stimulation of peripheral blood lymphocytes with ovalbumin followed by stimulation with PMA/ionomycin allowed the identification by flow cytometry of CD4+ T cells producing either IL-17A, IFN-γ, or both cytokines. The results indicate that the antigen-specific WBA, and specifically IL-17A and IFN-γ production by circulating CD4+ cells, can be used as a predictor of mammary hypersensitivity to protein antigens. This prompts further studies aiming at determining how Th17 and/or Th1 lymphocytes modulate the immune response of the mammary gland to infection. PMID:26375594

  10. Activated human mesenchymal stem/stromal cells suppress metastatic features of MDA-MB-231 cells by secreting IFN-β.

    PubMed

    Yoon, N; Park, M S; Shigemoto, T; Peltier, G; Lee, R H

    2016-01-01

    Our recent study showed that human mesenchymal stem/stromal cells (hMSCs) are activated to express tumor necrosis factor (TNF)-α-related apoptosis-inducing ligand (TRAIL) by exposure to TNF-α and these activated hMSCs effectively induce apoptosis in triple-negative breast cancer MDA-MB-231 (MDA) cells in vitro and in vivo. Here, we further demonstrated that activated hMSCs not only induced apoptosis of MDA cells but also reduced metastatic features in MDA cells. These activated hMSC-exposed MDA cells showed reduced tumorigenicity and suppressed formation of lung metastasis when implanted in the mammary fat pad. Surprisingly, the activated hMSC-exposed MDA cells increased TRAIL expression, resulting in apoptosis in MDA cells. Interestingly, upregulation of TRAIL in MDA cells was mediated by interferon-beta (IFN-β) secreted from activated hMSCs. Furthermore, IFN-β in activated hMSCs was induced by RNA and DNA released from apoptotic MDA cells in absent in melanoma 2 (AIM2) and IFN induced with helicase C domain 1 (IFIH1)-dependent manners. These observations were only seen in the TRAIL-sensitive breast cancer cell lines but not in the TRAIL-resistant breast cancer cell lines. Consistent with these results, Kaplan-Meier survival analysis also showed that lack of innate sensors detecting DNA or RNA is strongly associated with poor survival in estrogen receptor-negative breast cancer patients. In addition, cancer-associated fibroblasts (CAF) isolated from a breast cancer patient were also able to express TRAIL and IFN-β upon DNA and RNA stimulation. Therefore, our results suggest that the crosstalk between TRAIL-sensitive cancer cells and stromal cells creates a tumor-suppressive microenvironment and further provide a novel therapeutic approach to target stromal cells within cancer microenvironment for TRAIL sensitive cancer treatment. PMID:27077807

  11. Ex vivo recovery and activation of dysfunctional, anergic, monocyte-derived dendritic cells from patients with operable breast cancer: critical role of IFN-alpha

    PubMed Central

    Satthaporn, Sukchai; Aloysius, Mark M; Robins, Richard A; Verma, Chandan; Chuthapisith, Suebwong; Mckechnie, Alasdair J; El-Sheemy, Mohamad; Vassanasiri, Wichai; Valerio, David; Clark, David; Jibril, Jibril A; Eremin, Oleg

    2008-01-01

    Background Dendritic cells (DCs) play a crucial role in initiating effective cell-mediated immune responses, but are dysfunctional and anergic in breast cancer. Reversal of this dysfunction and establishment of optimal DC function is a key prerequisite for the induction of effective anti-cancer immune responses. Results Peripheral blood DCs (PBDCs) and lymph node DCs (LNDCs) generated in vitro from adherent cultures of peripheral blood monocytes (PBMs) and lymph node monocytes (LNMs), respectively, using the 4 cytokine conditioned medium (CCM) (GM-CSF+IL-4+TNF-α+IFN-α) or 3 CCM (GM-CSF+IL-4+TNF-α) demonstrated a significantly higher degree of recovery and functional capacity in a mixed lymphocyte DC reaction (MLDCR, p < 0.001), expressed significantly higher levels of HLA-DR, CD86, compared with 2 CCM (GM-CSF+IL-4) or medium alone generated DCs from PBMs and LNMs (p < 0.001). The PBDCs generated with 3 CCM or 4 CCM showed a significantly (p < 0.001) enhanced macropinocytotic capability (dextran particles) and induced increased production and secretion of interleukin-12p40 (IL-12p40) in vitro (p < 0.001), compared with PBDCs generated from monocytes using 2 CCM or medium alone. Lipopolysaccharide (LPS) stimulation of PBDCs generated with 4 CCM demonstrated enhanced secretion of IL-6 but not IL-12p70, compared with control DCs unstimulated with LPS (p < 0.001). Conclusion Dysfunctional and anergic PBDCs and LNDCs from patients with operable breast cancer can be optimally reversed by ex vivo culturing of precursor adherent monocytes using a 4 CCM containing IFN-α. Maximal immunophenotypic recovery and functional reactivation of DCs is seen in the presence of IFN-α. However, 4 CCM containing IFN-α generated-PBDCs, do not produce and secrete IL-12p70 in vitro. PMID:18588665

  12. Activated human mesenchymal stem/stromal cells suppress metastatic features of MDA-MB-231 cells by secreting IFN

    PubMed Central

    Yoon, N; Park, M S; Shigemoto, T; Peltier, G; Lee, R H

    2016-01-01

    Our recent study showed that human mesenchymal stem/stromal cells (hMSCs) are activated to express tumor necrosis factor (TNF)-α-related apoptosis-inducing ligand (TRAIL) by exposure to TNF-α and these activated hMSCs effectively induce apoptosis in triple-negative breast cancer MDA-MB-231 (MDA) cells in vitro and in vivo. Here, we further demonstrated that activated hMSCs not only induced apoptosis of MDA cells but also reduced metastatic features in MDA cells. These activated hMSC-exposed MDA cells showed reduced tumorigenicity and suppressed formation of lung metastasis when implanted in the mammary fat pad. Surprisingly, the activated hMSC-exposed MDA cells increased TRAIL expression, resulting in apoptosis in MDA cells. Interestingly, upregulation of TRAIL in MDA cells was mediated by interferon-beta (IFN-β) secreted from activated hMSCs. Furthermore, IFN-β in activated hMSCs was induced by RNA and DNA released from apoptotic MDA cells in absent in melanoma 2 (AIM2) and IFN induced with helicase C domain 1 (IFIH1)-dependent manners. These observations were only seen in the TRAIL-sensitive breast cancer cell lines but not in the TRAIL-resistant breast cancer cell lines. Consistent with these results, Kaplan–Meier survival analysis also showed that lack of innate sensors detecting DNA or RNA is strongly associated with poor survival in estrogen receptor-negative breast cancer patients. In addition, cancer-associated fibroblasts (CAF) isolated from a breast cancer patient were also able to express TRAIL and IFN-β upon DNA and RNA stimulation. Therefore, our results suggest that the crosstalk between TRAIL-sensitive cancer cells and stromal cells creates a tumor-suppressive microenvironment and further provide a novel therapeutic approach to target stromal cells within cancer microenvironment for TRAIL sensitive cancer treatment. PMID:27077807

  13. Hepatitis C Virus-Induced Myeloid-Derived Suppressor Cells Suppress NK Cell IFN-γ Production by Altering Cellular Metabolism via Arginase-1.

    PubMed

    Goh, Celeste C; Roggerson, Krystal M; Lee, Hai-Chon; Golden-Mason, Lucy; Rosen, Hugo R; Hahn, Young S

    2016-03-01

    The hepatitis C virus (HCV) infects ∼ 200 million people worldwide. The majority of infected individuals develop persistent infection, resulting in chronic inflammation and liver disease, including cirrhosis and hepatocellular carcinoma. The ability of HCV to establish persistent infection is partly due to its ability to evade the immune response through multiple mechanisms, including suppression of NK cells. NK cells control HCV replication during the early phase of infection and regulate the progression to chronic disease. In particular, IFN-γ produced by NK cells limits viral replication in hepatocytes and is important for the initiation of adaptive immune responses. However, NK cell function is significantly impaired in chronic HCV patients. The cellular and molecular mechanisms responsible for impaired NK cell function in HCV infection are not well defined. In this study, we analyzed the interaction of human NK cells with CD33(+) PBMCs that were exposed to HCV. We found that NK cells cocultured with HCV-conditioned CD33(+) PBMCs produced lower amounts of IFN-γ, with no effect on granzyme B production or cell viability. Importantly, this suppression of NK cell-derived IFN-γ production was mediated by CD33(+)CD11b(lo)HLA-DR(lo) myeloid-derived suppressor cells (MDSCs) via an arginase-1-dependent inhibition of mammalian target of rapamycin activation. Suppression of IFN-γ production was reversed by l-arginine supplementation, consistent with increased MDSC arginase-1 activity. These novel results identify the induction of MDSCs in HCV infection as a potent immune evasion strategy that suppresses antiviral NK cell responses, further indicating that blockade of MDSCs may be a potential therapeutic approach to ameliorate chronic viral infections in the liver. PMID:26826241

  14. Cloning and expression analyses of interferon regulatory factor (IRF) 3 and 7 genes in European eel, Anguilla anguilla with the identification of genes involved in IFN production.

    PubMed

    Huang, Bei; Huang, Wen Shu; Nie, P

    2014-04-01

    Interferon regulatory factor (IRF) 3 and IRF7 have been identified as regulators of type I interferon (IFN) gene expression in mammals. In the present study, the two genes were cloned and characterized in the European eel, Anguilla anguilla. The full-length cDNA sequence of IRF3 and IRF7 in the European eel, named as AaIRF3 and AaIRF7 consists of 2879 and 2419 bp respectively. Multiple alignments showed that the two IRFs have a highly conserved DNA binding domain (DBD) in the N terminus, with the characteristic motif containing five tryptophan residues, which is a feature present in their mammalian homologues. But, IRF7 has only four of the five residues in other species of fish. The expression of AaIRF3 and AaIRF7 both displayed an obvious dose-dependent manner following polyinosinic:polycytidylic acid (PolyI:C) challenge. In vivo expression analysis showed that the mRNA level of AaIRF3 and AaIRF7 was significantly up-regulated in response to PolyI:C stimulation in all examined tissues/organs except in muscle, with a lower level of increase observed in response to lipopolysaccharide (LPS) challenge and Edwardsiella tarda infection, indicating that AaIRF3 and AaIRF7 may be more likely involved in antiviral immune response. In addition, some pattern recognition receptors genes related with the production of type I IFNs and those genes in response to type I IFNs were identified in the European eel genome database, indicating a relatively conserved system in the production of type I IFN and its signalling in the European eel. PMID:24565894

  15. BETA DEFENSIN 2 AND 3 PROMOTE THE UPTAKE OF SELF OR CpG DNA, ENHANCE IFN-α PRODUCTION BY HUMAN PLASMACYTOID DENDRITIC CELLS AND PROMOTE INFLAMMATION

    PubMed Central

    Tewary, Poonam; dela Rosa, Gonzalo; Sharma, Neeraj; Rodriguez, Luis G; Tarasov, Sergey G; Howard, OM Zack; Shirota, Hidekazu; Steinhagen, Folkert; Klinman, Dennis M.; Yang, De; Oppenheim, Joost J.

    2013-01-01

    Alarmins are a group of structurally diverse host defense antimicrobial peptides that are important immune activators. Here we present a novel role of two potent alarmins, human beta defensin 2 and 3 (HBD2 and 3) in promoting IFN-α production by human plasmacytoid DCs (pDCs). We demonstrate that HBD2 and 3 activate pDCs by enhancing the intracellular uptake of CpG and self DNA and promote DNA induced IFN-α production in a TLR9 dependent manner. Both CpG and host DNA form aggregates that resemble DNA nets when combined with HBD2 and 3. Isothermal Titration Calorimetry (ITC) studies to elucidate the nature of HBD3-CpG complexes demonstrates involvement of enthalpy driven interactions in addition to hydrophobic interactions with the formation of complexes at a molar ratio of 2:1 defensin/CpG. Intravenous administration of HBD3-CpG complexes induced proinflammatory cytokines like IL-12, IFN-γ, IL-6, IFN-α and IL-10 in serum associated with an increased recruitment of antigen presenting cells (APCs) in the spleen. Subcutaneous injections of these complexes showed enhanced infiltration of inflammatory cells at injection site indicating a potential pathophysiological role of alarmin/DNA complexes in contributing to inflammation. Intraperitoneal immunization of HBD3/CpG complexes with OVA enhanced both cellular and humoral responses in response to OVA as compared to OVA/HBD3 or OVA/CPG alone, indicative of a much more potent adjuvant effect of the HBD3/CpG complexes. Thus the ability of defensins to enhance cellular uptake of nucleic acids can lead to improved vaccine formulations by promoting their uptake by various cells resulting in an enhanced immune response. PMID:23776172

  16. Ubiquilin 1 Promotes IFN-γ-Induced Xenophagy of Mycobacterium tuberculosis

    PubMed Central

    Sakowski, Erik T.; Shrestha, Elina; Hetzenecker, Stefanie E.; Maurer, Katie; Cadwell, Ken; Philips, Jennifer A.

    2015-01-01

    The success of Mycobacterium tuberculosis (Mtb) as a pathogen rests upon its ability to grow intracellularly in macrophages. Interferon-gamma (IFN-γ) is critical in host defense against Mtb and stimulates macrophage clearance of Mtb through an autophagy pathway. Here we show that the host protein ubiquilin 1 (UBQLN1) promotes IFN-γ-mediated autophagic clearance of Mtb. Ubiquilin family members have previously been shown to recognize proteins that aggregate in neurodegenerative disorders. We find that UBQLN1 can interact with Mtb surface proteins and associates with the bacilli in vitro. In IFN-γ activated macrophages, UBQLN1 co-localizes with Mtb and promotes the anti-mycobacterial activity of IFN-γ. The association of UBQLN1 with Mtb depends upon the secreted bacterial protein, EsxA, which is involved in permeabilizing host phagosomes. In autophagy-deficient macrophages, UBQLN1 accumulates around Mtb, consistent with the idea that it marks bacilli that traffic through the autophagy pathway. Moreover, UBQLN1 promotes ubiquitin, p62, and LC3 accumulation around Mtb, acting independently of the E3 ligase parkin. In summary, we propose a model in which UBQLN1 recognizes Mtb and in turn recruits the autophagy machinery thereby promoting intracellular control of Mtb. Thus, polymorphisms in ubiquilins, which are known to influence susceptibility to neurodegenerative illnesses, might also play a role in host defense against Mtb. PMID:26225865

  17. Pulmonary Fibrosis Treated with Inhaled Interferon-gamma (IFN-γ).

    PubMed

    Fusiak, Timothy; Smaldone, Gerald C; Condos, Rany

    2015-10-01

    Parenteral IFN-γ was unsuccessful as a treatment for pulmonary fibrosis. Inhaled IFN-γ targeted to the lungs may be more effective. Our patient, a 56-year-old male with biopsy proven usual interstitial pneumonia (UIP) and declining pulmonary function tests (PFTs) was initially diagnosed with idiopathic pulmonary fibrosis (IPF). He enrolled in a 2-year research protocol and was treated with inhaled IFN-γ (100 μg, Actimmune, Horizon Pharma, Deerfield, IL) 3 times per week. After completion of the protocol, he was able to secure the drug and continued therapy for a total of 7 years. He felt better, returning to work. His only complaint was transient cough during inhalation. PFTs improved (e.g., DLCO, 58% at baseline, 81% at 2 years, 69% currently). Clinical monitoring showed preserved exercise tolerance and stable CT scans. He was ultimately diagnosed (year 5) with scleroderma-like connective tissue disease after he developed sclerodactyly and a positive antinuclear antibody. Inhaled IFN-γ was well tolerated for 7 years and may stabilize fibrotic lung disease. PMID:26327351

  18. IFN-γ Hinders Recovery from Mucosal Inflammation during Antibiotic Therapy for Salmonella Gut Infection.

    PubMed

    Dolowschiak, Tamas; Mueller, Anna Angelika; Pisan, Lynn Joanna; Feigelman, Rounak; Felmy, Boas; Sellin, Mikael Erik; Namineni, Sukumar; Nguyen, Bidong Dinh; Wotzka, Sandra Yvonne; Heikenwalder, Mathias; von Mering, Christian; Mueller, Christoph; Hardt, Wolf-Dietrich

    2016-08-10

    Salmonella Typhimurium (S.Tm) causes acute enteropathy resolving after 4-7 days. Strikingly, antibiotic therapy does not accelerate disease resolution. We screened for factors blocking remission using a S.Tm enterocolitis model. The antibiotic ciprofloxacin clears pathogen stool loads within 3-24 hr, while gut pathology resolves more slowly (ψ50: ∼48 hr, remission: 6-9 days). This delayed resolution is mediated by an interferon-γ (IFN-γ)-dependent response that is triggered during acute infection and continues throughout therapy. Specifically, IFN-γ production by mucosal T and NK cells retards disease resolution by maintaining signaling through the transcriptional regulator STAT1 and boosting expression of inflammatory mediators like IL-1β, TNF, and iNOS. Additionally, sustained IFN-γ fosters phagocyte accumulation and hampers antimicrobial defense mediated by IL-22 and the lectin REGIIIβ. These findings reveal a role for IFN-γ in delaying resolution of intestinal inflammation and may inform therapies for acute Salmonella enteropathy, chronic inflammatory bowel diseases, or disease resolution during antibiotic treatment. PMID:27453483

  19. HER-2/neu raises SHP-2, stops IFN-{gamma} anti-proliferation in bladder cancer

    SciTech Connect

    Su, W.-P.; Tu, I-H.; Hu, S.-W.; Yeh, H.-H.; Shieh, D.-B.; Chen, T.-Y.; Su, W.-C. . E-mail: sunnysu@mail.ncku.edu.tw

    2007-04-27

    Gene amplification or HER-2/neu protein overexpression signals a poor outcome for bladder cancer patients. We investigated the anti-proliferative effect of IFN-{gamma} in HER-2/neu-transfected human bladder cancer cells (TCC-N5 and TCC-N10). The cells continued growing after IFN-{gamma} stimulation but did not activate the Janus kinase (Jak)/Stat pathway. We found Jak/Stat protein phosphatase in TCC-N5 and TCC-N10 cells with upregulated Src homology 2-containing protein tyrosine phosphatase-2 (SHP-2). After the cells had been treated with AG825, a HER-2/neu-specific inhibitor, SHP-2 expression declined, and Jak2/Stat1 reactivated. Similar results were reported in a mouse bladder cancer cell line, MBT2, with constitutive HER-2/neu overexpression. Further, AG825 pretreatment restored the anti-proliferation activity of IFN-{gamma} in TCC-N5 and TCC-N10 cells. Therefore, the suppression of IFN-{gamma} signaling in HER-2/neu-overexpressing bladder cancer cells might be due to SHP-2 upregulation. The regulation of SHP-2 by HER-2/neu provides a new target for blocking the HER-2/neu oncogenic pathwa000.

  20. Development of a Second Generation Bovigam Interferon Gamma (IFN-gamma) Assay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In search for better tools to control bovine tuberculosis, the development of diagnostic tests with improved performance and enhanced ease-of-use has a high priority. BOVIGAM®, a rapid laboratory assay, measures gamma interferon (IFN-gamma) production in whole blood samples after induction of a ce...

  1. G2A Signaling Dampens Colitic Inflammation via Production of IFN-γ.

    PubMed

    Frasch, S Courtney; McNamee, Eóin N; Kominsky, Douglas; Jedlicka, Paul; Jakubzick, Claudia; Zemski Berry, Karin; Mack, Matthias; Furuta, Glenn T; Lee, James J; Henson, Peter M; Colgan, Sean P; Bratton, Donna L

    2016-08-15

    Proinflammatory consequences have been described for lysophosphatidylcholine, a lipid product of cellular injury, signaling via the G protein-coupled receptor G2A on myeloid and lymphoid inflammatory cells. This prompted the hypothesis that genetic deletion of G2A would limit intestinal inflammation in a mouse model of colitis induced by dextran sodium sulfate. Surprisingly, G2A(-/-) mice exhibited significantly worsened colitis compared with wild-type mice, as demonstrated by disease activity, colon shortening, histology, and elevated IL-6 and IL-5 in colon tissues. Investigation of inflammatory cells recruited to inflamed G2A(-/-) colons showed significantly more TNF-α(+) and Ly6C(hi)MHCII(-) proinflammatory monocytes and eosinophils than in wild-type colons. Both monocytes and eosinophils were pathogenic as their depletion abolished the excess inflammation in G2A(-/-) mice. G2A(-/-) mice also had less IFN-γ in inflamed colon tissues than wild-type mice. Fewer CD4(+) lymphocytes were recruited to inflamed G2A(-/-) colons, and fewer colonic lymphocytes produced IFN-γ upon ex vivo stimulation. Administration of IFN-γ to G2A(-/-) mice during dextran sodium sulfate exposure abolished the excess colitic inflammation and reduced colonic IL-5 and eosinophil numbers to levels seen in wild-type mice. Furthermore, IFN-γ reduced the numbers of TNF-α(+) monocyte and enhanced their maturation from Ly6C(hi)MHCII(-) to Ly6C(int)MHCII(+) Taken together, the data suggest that G2A signaling serves to dampen intestinal inflammation via the production of IFN-γ, which, in turn, enhances monocyte maturation to a less inflammatory program and ultimately reduces eosinophil-induced injury of colonic tissues. PMID:27402702

  2. Association between IFN-γ +874A/T and IFN-γR1 (-611A/G, +189T/G, and +95C/T) Gene Polymorphisms and Chronic Periodontitis in a Sample of Iranian Population.

    PubMed

    Heidari, Zahra; Mahmoudzadeh-Sagheb, Hamidreza; Hashemi, Mohammad; Ansarimoghaddam, Somayeh; Moudi, Bita; Sheibak, Nadia

    2015-01-01

    Background. Interferon gamma (IFN-γ) is an immune regulatory cytokine that acts through its receptor and plays important role in progression of inflammatory disease such as chronic periodontitis (CP). The purpose of this study was to determine the differences in the distribution of IFN-γ (+874A/T) and IFN-γR1 (-611A/G, +189T/G, and +95C/T) gene polymorphisms among CP and healthy individuals and to investigate relationships between these polymorphisms and susceptibility to CP. Materials and Methods. 310 individuals were enrolled in the study including 210 CP patients and 100 healthy controls. Single nucleotide polymorphisms at IFN-γ (+874A/T) and IFN-γR1 (-611A/G, +189T/G, and +95C/T) were analyzed by ARMS-PCR and PCR-RFLP methods. Results. The significant difference was found in genotype and allele frequency of IFN-γ (+874A/T) gene polymorphism in chronic periodontitis patients and healthy controls. The distribution of genotypes and allele frequencies for IFN-γR1 (-611A/G, +189T/G, and +95C/T) were similar among the groups and no differences in the frequencies of alleles or genotypes of IFN-γR1 genetic polymorphisms variants between case and control groups were detected. Conclusion. The finding of this study showed that IFN-γ +874A/T gene polymorphism may affect susceptibility to CP, whereas IFN-γR1 genetic polymorphisms at -611A/G, +189T/G, and +95C/T were not associated with this disease. PMID:26823666

  3. Association between IFN-γ +874A/T and IFN-γR1 (-611A/G, +189T/G, and +95C/T) Gene Polymorphisms and Chronic Periodontitis in a Sample of Iranian Population

    PubMed Central

    Heidari, Zahra; Mahmoudzadeh-Sagheb, Hamidreza; Hashemi, Mohammad; Ansarimoghaddam, Somayeh; Moudi, Bita; Sheibak, Nadia

    2015-01-01

    Background. Interferon gamma (IFN-γ) is an immune regulatory cytokine that acts through its receptor and plays important role in progression of inflammatory disease such as chronic periodontitis (CP). The purpose of this study was to determine the differences in the distribution of IFN-γ (+874A/T) and IFN-γR1 (-611A/G, +189T/G, and +95C/T) gene polymorphisms among CP and healthy individuals and to investigate relationships between these polymorphisms and susceptibility to CP. Materials and Methods. 310 individuals were enrolled in the study including 210 CP patients and 100 healthy controls. Single nucleotide polymorphisms at IFN-γ (+874A/T) and IFN-γR1 (-611A/G, +189T/G, and +95C/T) were analyzed by ARMS-PCR and PCR-RFLP methods. Results. The significant difference was found in genotype and allele frequency of IFN-γ (+874A/T) gene polymorphism in chronic periodontitis patients and healthy controls. The distribution of genotypes and allele frequencies for IFN-γR1 (-611A/G, +189T/G, and +95C/T) were similar among the groups and no differences in the frequencies of alleles or genotypes of IFN-γR1 genetic polymorphisms variants between case and control groups were detected. Conclusion. The finding of this study showed that IFN-γ +874A/T gene polymorphism may affect susceptibility to CP, whereas IFN-γR1 genetic polymorphisms at -611A/G, +189T/G, and +95C/T were not associated with this disease. PMID:26823666

  4. STAT1 deficiency redirects IFN signalling toward suppression of TLR response through a feedback activation of STAT3

    PubMed Central

    Kim, Hun Sik; Kim, Dong Chan; Kim, Hong-Mi; Kwon, Hyung-Joon; Kwon, Soon Jae; Kang, Suk-Jo; Kim, Sun Chang; Choi, Go-Eun

    2015-01-01

    Interferons (IFNs) potentiate macrophage activation typically via a STAT1-dependent pathway. Recent studies suggest a functioning of STAT1-independent pathway in the regulation of gene expression by IFN-γ, thus pointing to the diversity in cellular responses to IFNs. Many functions of IFNs rely on cross-regulation of the responses to exogenous inflammatory mediators such as TLR ligands. Here we investigated the contribution of STAT1-independent pathway to macrophage activation and its underlying mechanism in the context of combined stimulation of IFN and TLR. We found that TLR-induced production of inflammatory cytokines (TNF-α, IL-12) was not simply nullified but was significantly suppressed by signaling common to IFN-γ and IFN-β in STAT1-null macrophages. Such a shift in the suppression of TLR response correlated with a sustained STAT3 activation and attenuation of NF-κB signaling. Using a JAK2/STAT3 pathway inhibitor or STAT3-specific siRNA, blocking STAT3 in that context restored TNF-α production and NF-κB signaling, thus indicating a functional cross-regulation among STAT1, STAT3, and NF-κB. Our results suggest that STAT1 deficiency reprograms IFN signaling from priming toward suppression of TLR response via feedback regulation of STAT3, which may provide a new insight into the host defense response against microbial pathogens in a situation of STAT1 deficiency. PMID:26299368

  5. Human metapneumovirus small hydrophobic (SH) protein downregulates type I IFN pathway signaling by affecting STAT1 expression and phosphorylation.

    PubMed

    Hastings, Andrew K; Amato, Katherine R; Wen, Sherry C; Peterson, Laura S; Williams, John V

    2016-07-01

    Type I interferon (IFN) is a key mediator of antiviral immunity. Human metapneumovirus (HMPV) inhibits IFN signaling, but does not encode homologues of known IFN antagonists. We tested the hypothesis that a specific viral protein prevents type I IFN signaling by targeting signal transducer and activator of transcription-1 (STAT1). We found that human airway epithelial cells (capable of expressing IFNs) became impaired for STAT1 phosphorylation even without direct infection due to intrinsic negative feedback. HMPV-infected Vero cells (incapable of expressing IFN) displayed lower STAT1 expression and impaired STAT1 phosphorylation in response to type I IFN treatment compared to mock-infected cells. Transient overexpression of HMPV small hydrophobic (SH) protein significantly inhibited STAT1 phosphorylation and signaling, and recombinant virus lacking SH protein was unable to inhibit STAT1 phosphorylation. Our results indicate a role for the SH protein of HMPV in the downregulation of type I IFN signaling through the targeting of STAT1. PMID:27131212

  6. Exogenous IFN-alpha Administration Reduces Influenza A Virus Replication in the Lower Respiratory Tract of Rhesus Macaques

    PubMed Central

    Matzinger, Shannon R.; Carroll, Timothy D.; Fritts, Linda; McChesney, Michael B.; Miller, Christopher J.

    2011-01-01

    To determine the role of innate immune responses in controlling influenza A virus replication, rhesus macaques (RM) were administered pegylated IFN-alpha prior to virus challenge. Systemic and mucosal pegylated IFN-alpha administration induced expression of the interferon-stimulated genes (ISG) MxA and OAS in the airways. RM treated with IFN-alpha 24 hours prior to influenza virus challenge had significantly lower peak vRNA levels in the trachea compared to untreated animals. In addition to blunting viral replication, IFN-alpha treatment minimized the weight loss and spike in body temperature after influenza infection of RM. These results confirm the importance of IFN-alpha induced innate immune responses in the rapid control of influenza A virus replication in primates. PMID:22220209

  7. IL-2, IL-4, IFN-γ or TNF-α enhances BAFF-stimulated cell viability and survival by activating Erk1/2 and S6K1 pathways in neoplastic B-lymphoid cells.

    PubMed

    Gui, Lin; Zeng, Qingyu; Xu, Zhigang; Zhang, Hai; Qin, Shanshan; Liu, Chunxiao; Xu, Chong; Qian, Zhou; Zhang, Shuangquan; Huang, Shile; Chen, Long

    2016-08-01

    B-cell activating factor of the TNF family (BAFF) has been documented to act as a critical factor in the development of aggressive B lymphocytes and autoimmune diseases. However, the effect of various cytokines on BAFF-elicited neoplastic B-lymphoid cells is not known. In this study, we exhibited that administration of human soluble BAFF (hsBAFF), IL-2, IL-4, IFN-γ, or TNF-α alone increased cell viability and survival in Raji cells concentration-dependently, yet a more robust viability/survival was seen in the cells co-treatment of IL-2, IL-4, IFN-γ, or TNF-α with hsBAFF, respectively. Further research revealed that both Erk1/2 and S6K1 signaling pathways were essential for IL-2, IL-4, IFN-γ, or TNF-α enhancement of the viability/survival in the hsBAFF-stimulated cells, as inhibition of Erk1/2 with U0126 or down-regulation of Erk1/2, or blockage of S6K1 with rapamycin or silencing S6K1, or silencing S6K1/Erk1/2, respectively, reduced the cell viability/survival in the cells treated with/without hsBAFF±IL-2, IL-4, IFN-γ, or TNF-α. These findings indicate that IL-2, IL-4, IFN-γ or TNF-α enhances BAFF-stimulated cell viability/survival by activating Erk1/2 and S6K1 signaling in neoplastic B-lymphoid cells. Our data suggest that modulation of IL-2, IL-4, IFN-γ and/or TNF-α levels, or inhibitors of Erk1/2 or S6K1 may be a new approach to prevent BAFF-induced aggressive B-cell malignancies. PMID:27235588

  8. High Pulmonary Levels of IL-6 and IL-1β in Children with Chronic Suppurative Lung Disease Are Associated with Low Systemic IFN-γ Production in Response to Non-Typeable Haemophilus influenzae

    PubMed Central

    Pizzutto, Susan J.; Upham, John W.; Yerkovich, Stephanie T.; Chang, Anne B.

    2015-01-01

    Non-typeable Haemophilus influenzae (NTHi) is commonly associated with chronic suppurative lung disease in children. We have previously shown that children with chronic suppurative lung disease have a reduced capacity to produce IFN-γ in response to NTHi compared with healthy control children. The aim of this study was to determine if deficient NTHi-specific IFN-γ production is associated with heightened systemic or airway inflammation. We measured a panel of cytokines (IFN-γ, IL-1β, IL-6, IL-8, IL-12 p70), antimicrobial proteins (LL-37, IP-10) as well as cellular and clinical factors associated with airway and systemic inflammation in 70 children with chronic suppurative lung disease. IFN-γ was measured in peripheral blood mononuclear cells challenged in vitro with live NTHi. Regression analysis was used to assess the association between the systemic and airway inflammation and the capacity to produce IFN-γ. On multivariate regression, NTHi-specific IFN-γ production was significantly negatively associated with the BAL concentrations of the inflammatory cytokines IL-6 (β=-0.316; 95%CI -0.49, -0.14; p=0.001) and IL-1β (β=-0.023; 95%CI -0.04, -0.01; p=0.001). This association was independent of bacterial or viral infection, BAL cellularity and the severity of bronchiectasis (using modified Bhalla score on chest CT scans). We found limited evidence of systemic inflammation in children with chronic suppurative lung disease. In summary, increased local airway inflammation is associated with a poorer systemic cell-mediated immune response to NTHi in children with chronic suppurative lung disease. These data support the emerging body of evidence that impaired cell-mediated immune responses and dysregulated airway inflammation may be linked and contribute to the pathobiology of chronic suppurative lung disease. PMID:26066058

  9. Enhancing Specific-Antibody Production to the ragB Vaccine with GITRL That Expand Tfh, IFN-γ+ T Cells and Attenuates Porphyromonas gingivalis Infection in Mice

    PubMed Central

    Su, Zhaoliang; Kong, Fanzhi; Shi, Xiaoju; Tong, Jia; Shen, Pei; Peng, Tianqing; Wang, Shengjun; Xu, Huaxi

    2013-01-01

    The outer membrane protein RagB is one of the major virulence factors of the periodontal pathogen Porphyromonas gingivalis (P. gingivalis). In order to induce protective immune response against P. gingivalis infection, an mGITRL gene-linked ragB DNA vaccine (pIRES-ragB-mGITRL ) was constructed. Six-week-old female BALB/c mice were immunized with pIRES-ragB-mGITRL through intramuscular injection and then challenged by subcutaneous injection in the abdomen with P. gingivalis. RagB-specific antibody-forming cells were evaluated by an Enzyme-linked immunosorbent spot, and specific antibody was determined by enzyme-linked immunosorbent assay. In addition, the frequencies of Tfh and IFN-γ+ T cells in spleen were measured using flow cytometer, and the levels of IL-21 and IFN-γ mRNA or proteins were detected by real time RT-PCR or ELISA. The data showed that the mGITRL-linked ragB DNA vaccine induced higher levels of RagB-specific IgG in serum and RagB-specific antibody-forming cells in spleen. The frequencies of Tfh and IFN-γ+ T cells were obviously expanded in mice immunized by pIRES-ragB-mGITRL compared with other groups (pIRES or pIRES-ragB ). The levels of Tfh and IFN-γ+ T cells associated cytokines were also significantly increased in pIRES-ragB-mGITRL group. Therefore, the mice immunized with ragB plus mGITRL showed the stronger resistant to P. gingivalis infection and a significant reduction of the lesion size caused by P. gingivalis infection comparing with other groups. Taken together, our findings demonstrated that intramuscular injection of DNA vaccine ragB together with mGITRL induced protective immune response dramatically by increasing Tfh and IFN-γ+ T cells and antibody production to P. gingivalis. PMID:23560053

  10. N-3 polyunsaturated fatty acids inhibit IFN-γ-induced IL-18 binding protein production by prostate cancer cells.

    PubMed

    Wang, Xiaofeng; Breeze, Andrew; Kulka, Marianna

    2015-02-01

    Prostate cancer cells can produce IL-18 binding protein (IL-18BP) in response to interferon-γ (IFN-γ), which may function to neutralize IL-18, an anti-tumor factor formerly known as IFN-γ inducing factor. The consumption of n-3 polyunsaturated fatty acids (PUFAs) has been associated with a lower risk of certain types of cancer including prostate cancer, although the precise mechanisms of this effect are poorly understood. We hypothesized that n-3 PUFAs could modify IL-18BP production by prostate cancer cells by altering IFN-γ receptor-mediated signal transduction. Here, we demonstrate that n-3 PUFA treatment significantly reduced IFN-γ-induced IL-18BP production by DU-145 and PC-3 prostate cancer cells by inhibiting IL-18BP mRNA expression and was associated with a reduction in IFN-γ receptor expression. Furthermore, IFN-γ-induced phosphorylation of Janus kinase 1 (JAK1), signal transducers and activators of transcription 1 (STAT1), extracellular signal-regulated kinases 1/2 (ERK1/2), and P38 were suppressed by n-3 PUFA treatment. By contrast, n-6 PUFA had no effect on IFN-γ receptor expression, but decreased IFN-γ-induced IL-18BP production and IFN-γ stimulation of JAK1, STAT1, ERK1/2, and JNK phosphorylation. These data indicate that both n-3 and n-6 PUFAs may be beneficial in prostate cancer by altering IFN-γ signaling, thus inhibiting IL-18BP production and thereby rendering prostate cancer cells more sensitive to IL-18-mediated immune responses. PMID:25351720

  11. Monoclonal antibody against IFN-gamma inhibits Moloney murine sarcoma virus-specific cytotoxic T lymphocyte differentiation

    SciTech Connect

    Zanovello, P.; Vallerani, E.; Biasi, G.; Landolfo, S.; Collavo, D.

    1988-02-15

    The role of autochthonous IFN- production was evaluated in immune reactions to Moloney murine sarcoma virus (M-MSV)-induced tumors which are characterized by spontaneous regression mainly caused by virus-specific CTL activity. A functional IFN- depletion, induced by repeated administration of mAb anti-IFN- at the site of virus inoculation, prevented tumor regression in M-MSV-injected mice. Moreover, this antibody inhibited in vitro both proliferation and differentiation of M-MSV-specific T lymphocytes obtained in bulk cultures, but not growth and lytic activity of the already differentiated virus-specific CTL clone CHM-14 stimulated with rIL-2 and relevant tumor Ag. In addition, in mice receiving mAb treatment the frequency of M-MSV-specific CTL precursors, evaluated by means of limiting dilution analysis, was strongly reduced in comparison with that of control mice injected only with virus. Because CTL secrete IFN- following antigenic stimulation, the possibility that non-T effector cells recruited by this lymphokine might mediate tumor regression was also considered. Adoptive immunotherapy experiments, performed in T cell-deficient (Tx + BM) and in sublethally irradiated mice, demonstrated that transfer of CHM-14 CTL clone, which secretes IFN-, was able to counteract M-MSV tumor growth despite the local mAb anti-IFN- treatment which may have prevented host cell recruitment. Moreover, repeated local rIFN- inoculations in Tx + BM mice did not counteract M-MSV tumor progression, thus confirming that other IFN- properties such as non-T cell recruitment, antiviral or anti-proliferative IFN- activities have little or no relevance when M-MSV-specific CTL are lacking. On the whole, these results indicate that in M-MSV-injected mice, tumor enhancement after mAb anti-IFN- treatment is principally caused by impaired differentiation of virus-specific CTL precursors.

  12. Blocking the PI3K/AKT pathway enhances mammalian reovirus replication by repressing IFN-stimulated genes

    PubMed Central

    Tian, Jin; Zhang, Xiaozhan; Wu, Hongxia; Liu, Chunguo; Li, Zhijie; Hu, Xiaoliang; Su, Shuo; Wang, Lin-Fa; Qu, Liandong

    2015-01-01

    Many host cellular signaling pathways were activated and exploited by virus infection for more efficient replication. The PI3K/Akt pathway has recently attracted considerable interest due to its role in regulating virus replication. This study demonstrated for the first time that the mammalian reovirus strains Masked Palm Civet/China/2004 (MPC/04) and Bat/China/2003 (B/03) can induce transient activation of the PI3K/Akt pathway early in infection in vitro. When UV-treated, both viruses activated PI3K/Akt signaling, indicating that the virus/receptor interaction was sufficient to activate PI3K/Akt. Reovirus virions can use both clathrin- and caveolae-mediated endocytosis, but only chlorpromazine, a specific inhibitor of clathrin-mediated endocytosis, or siRNA targeting clathrin suppressed Akt phosphorylation. We also identified the upstream molecules of the PI3K pathway. Virus infection induced phosphorylation of focal adhesion kinase (FAK) but not Gab1, and blockage of FAK phosphorylation suppressed Akt phosphorylation. Blockage of PI3K/Akt activation increased virus RNA synthesis and viral yield. We also found that reovirus infection activated the IFN-stimulated response element (ISRE) in an interferon-independent manner and up-regulated IFN-stimulated genes (ISGs) via the PI3K/Akt/EMSY pathway. Suppression of PI3K/Akt activation impaired the induction of ISRE and down-regulated the expression of ISGs. Overexpression of ISG15 and Viperin inhibited virus replication, and knockdown of either enhanced virus replication. Collectively, these results demonstrate that PI3K/Akt activated by mammalian reovirus serves as a pathway for sensing and then inhibiting virus replication/infection. PMID:26388843

  13. TNF-alpha, but not IFN-gamma, regulates CCN2 (CTGF), collagen type I, and proliferation in mesangial cells: possible roles in the progression of renal fibrosis.

    PubMed

    Cooker, Laurinda A; Peterson, Darryl; Rambow, Joann; Riser, Melisa L; Riser, Rebecca E; Najmabadi, Feridoon; Brigstock, David; Riser, Bruce L

    2007-07-01

    Connective tissue growth factor (CCN2) is a profibrotic factor acting downstream and independently of TGF-beta to mediate renal fibrosis. Although inflammation is often involved in the initiation and/or progression of fibrosis, the role of inflammatory cytokines in regulation of glomerular CCN2 expression, cellular proliferation, and extracellular matrix accumulation is unknown. We studied two such cytokines, TNF-alpha and IFN-gamma, for their effects on cultured mesangial cells in the presence or absence of TGF-beta, as a model for progressive renal fibrosis. Short-term treatment with TNF-alpha, like TGF-beta, significantly increased secreted CCN2 per cell, but unlike TGF-beta inhibited cellular replication. TNF-alpha combined with TGF-beta further increased CCN2 secretion and mRNA levels and reduced proliferation. Surprisingly, however, TNF-alpha treatment decreased baseline collagen type I protein and mRNA levels and largely blocked their stimulation by TGF-beta. Long-term treatment with TGF-beta or TNF-alpha alone no longer increased CCN2 protein levels. However, the combination synergistically increased CCN2. IFN-gamma had no effect on either CCN2 or collagen activity and produced a mild inhibition of TGF-beta-induced collagen only at a high concentration (500 U/ml). In summary, we report a strong positive regulatory role for TNF-alpha, but not IFN-gamma, in CCN2 production and secretion, including that driven by TGF-beta. The stimulation of CCN2 release by TNF-alpha, unlike TGF-beta, is independent of cellular proliferation and not linked to increased collagen type I accumulation. This suggests that the paradigm of TGF-beta-driven CCN2 with subsequent collagen production may be overridden by an as yet undefined inhibitory mechanism acting either directly or indirectly on matrix metabolism. PMID:17376761

  14. IFN-γ Directly Controls IL-33 Protein Level through a STAT1- and LMP2-dependent Mechanism*

    PubMed Central

    Kopach, Pavel; Lockatell, Virginia; Pickering, Edward M.; Haskell, Ronald E.; Anderson, Richard D.; Hasday, Jeffrey D.; Todd, Nevins W.; Luzina, Irina G.; Atamas, Sergei P.

    2014-01-01

    IL-33 contributes to disease processes in association with Th1 and Th2 phenotypes. IL-33 mRNA is rapidly regulated, but the fate of synthesized IL-33 protein is unknown. To understand the interplay among IL-33, IFN-γ, and IL-4 proteins, recombinant replication-deficient adenoviruses were produced and used for dual expression of IL-33 and IFN-γ or IL-33 and IL-4. The effects of such dual gene delivery were compared with the effects of similar expression of each of these cytokines alone. In lung fibroblast culture, co-expression of IL-33 and IFN-γ resulted in suppression of the levels of both proteins, whereas co-expression of IL-33 and IL-4 led to mutual elevation. In vivo, co-expression of IL-33 and IFN-γ in the lungs led to attenuation of IL-33 protein levels. Purified IFN-γ also attenuated IL-33 protein in fibroblast culture, suggesting that IFN-γ controls IL-33 protein degradation. Specific inhibition of caspase-1, -3, and -8 had minimal effect on IFN-γ-driven IL-33 protein down-regulation. Pharmacological inhibition, siRNA-mediated silencing, or gene deficiency of STAT1 potently up-regulated IL-33 protein expression levels and attenuated the down-regulating effect of IFN-γ on IL-33. Stimulation with IFN-γ strongly elevated the levels of the LMP2 proteasome subunit, known for its role in IFN-γ-regulated antigen processing. siRNA-mediated silencing of LMP2 expression abrogated the effect of IFN-γ on IL-33. Thus, IFN-γ, IL-4, and IL-33 are engaged in a complex interplay. The down-regulation of IL-33 protein levels by IFN-γ in pulmonary fibroblasts and in the lungs in vivo occurs through STAT1 and non-canonical use of the LMP2 proteasome subunit in a caspase-independent fashion. PMID:24619410

  15. Characterization of ATI, TK and IFN-alpha/betaR genes in the genome of the BeAn 58058 virus, a naturally attenuated wild Orthopoxvirus.

    PubMed

    Marques, J T; Trindade, G D; Da Fonseca, F G; Dos Santos, J R; Bonjardim, C A; Ferreira, P C; Kroon, E G

    2001-12-01

    The lack of knowledge about the natural host of Vaccinia virus (VV) along with the description of human infections caused by poxviruses after smallpox eradication has increased the need to characterize poxviruses isolated from the wild. Moreover, in the past years poxviruses have been widely studied as potential vaccination tools, with the discovery of several genes implicated in the evasion of the host immune response involved in virus pathogenesis. Among them, an Interferon (IFN)-binding protein was identified in the supernatant of VV strain WR infected cells coded by the B18R gene. It was shown that many other Orthopoxviruses also encode and express this soluble receptor although some VV strains such as Lister and modified Ankara, which were less reactogenic vaccines, do not. The BeAn 58058 virus (BAV) has been recently characterized and proposed to be an Orthopoxvirus. BAV was also shown to be less virulent in animal models than VV Lister. Here we report the identification of an IFN-alpha/betaR gene in the BAV genome with 99% of sequence identity with the VVWR B18R gene. The identified gene encodes a B18R-like IFN binding protein as demonstrated by its capacity to inhibit the IFN-mediated protection of VERO cells against EMC virus. In order to better characterize the virus we have searched for the A type inclusion body (ATI) gene currently used in the classification of Orthopoxviruses but did not detect it in the BAV genome. We have also sequenced the BAV thymidine kinase (TK) gene, a poxvirus-conserved gene, which, as expected, showed high homology with the TK gene of other poxviruses. Phylogenetic trees were constructed based on sequences of the IFN-alpha/betaR and TK genes from several poxviruses and in both cases BAV was placed in the same cluster as other VV strains. These observations strengthened the hypothesis that this virus is a variant of the VV vaccine used in Brazil. However the explanation for the BAV lack of virulence remains to be discovered

  16. Differential Cytotoxicity but Augmented IFN-γ Secretion by NK Cells after Interaction with Monocytes from Humans, and Those from Wild Type and Myeloid-Specific COX-2 Knockout Mice

    PubMed Central

    Tseng, Han-Ching; Arasteh, Aida; Kaur, Kawaljit; Kozlowska, Anna; Topchyan, Paytsar; Jewett, Anahid

    2015-01-01

    The list of genes, which augment NK cell function when knocked out in neighboring cells is increasing, and may point to the fundamental function of NK cells targeting cells with diminished capability to differentiate optimally since NK cells are able to target less differentiated cells, and aid in their differentiation. In this paper, we aimed at understanding the effect of monocytes from targeted knockout of COX-2 in myeloid cells (Cox-2flox/flox;LysMCre/+) and from control littermates (Cox-2flox/flox;LysM+/+) on ex vivo function of NK cells. Furthermore, we compared the effect of monocytes treated with and without lipopolysaccharide (LPS) on NK cells from mice and humans. NK cells purified from Cox-2flox/flox;LysMCre/+ mice had heightened cytotoxic activity when compared to those obtained from control littermates. In addition, NK cells cultured with autologous Cox-2flox/flox;LysMCre/+ monocytes and DCs, mouse embryonic fibroblasts from global knockout COX-2, but not with knockout of COX-2 in T cells, had increased cytotoxic function as well as augmented IFN-γ secretion when compared to NK cells from control littermates cultured with monocytes. LPS inhibited NK cell cytotoxicity while increasing IFN-γ secretion when cultured in the presence of monocytes from either Cox-2flox/flox;LysMCre/+ or control littermates. In contrast to mice, NK cells from humans when cultured with monocytes lost cytotoxic function and gained ability to secrete large amounts of IFN-γ, a process, which we had previously coined as “split anergy.” Similar to mice, LPS potentiated the loss of human NK cell cytotoxicity while increasing IFN-γ secretion in the presence of monocytes. Greater loss of cytotoxicity and larger secretion of IFN-γ in NK cells induced by gene knockout cells may be important for the greater need of these cells for differentiation. PMID:26106386

  17. Insulin regulates IL-1alpha, Ifn-y and IL-4 release from murine splenocytes stimulated with staphylococcal protein A, toxic shock syndrome toxin-1 and streptococcal lysin S.

    PubMed

    Sommese, L; Scarfogliero, P; Vitiello, M; Gorga, F; Galdiero, M

    1998-01-01

    In this study, changes were investigated in release of IL-1alpha, IFN-gamma and IL-4 from mouse splenocytes stimulated with staphylococcal protein A (SpA), toxic shock syndrome toxin-1 (TSST-1) or streptococcal lysin S (SLS) in the presence of insulin. The results show that insulin-treated splenocytes stimulated by SpA had a 25% increase in IFN-gamma release and a 50% decrease in IL-4 compared with splenocytes treated with SpA alone. IL-1alpha release was unchanged compared with controls. Insulintreated splenocytes stimulated with TSST-1 had a 30% fall in IL-1alpha and IFN-gamma release compared with controls. There were no changes in IL-4 release. Splenocytes stimulated with SLS after insulin treatment increased their release of IL-1alpha and IFN-gamma by 50%, whereas IL-4 release was unchanged. The data suggest that the insulin may have important functional implications in immunoregulation. PMID:17657628

  18. Glycosylation-Dependent IFN-γR Partitioning in Lipid and Actin Nanodomains Is Critical for JAK Activation.

    PubMed

    Blouin, Cédric M; Hamon, Yannick; Gonnord, Pauline; Boularan, Cédric; Kagan, Jérémy; Viaris de Lesegno, Christine; Ruez, Richard; Mailfert, Sébastien; Bertaux, Nicolas; Loew, Damarys; Wunder, Christian; Johannes, Ludger; Vogt, Guillaume; Contreras, Francesc-Xabier; Marguet, Didier; Casanova, Jean-Laurent; Galès, Céline; He, Hai-Tao; Lamaze, Christophe

    2016-08-11

    Understanding how membrane nanoscale organization controls transmembrane receptors signaling activity remains a challenge. We studied interferon-γ receptor (IFN-γR) signaling in fibroblasts from homozygous patients with a T168N mutation in IFNGR2. By adding a neo-N-glycan on IFN-γR2 subunit, this mutation blocks IFN-γ activity by unknown mechanisms. We show that the lateral diffusion of IFN-γR2 is confined by sphingolipid/cholesterol nanodomains. In contrast, the IFN-γR2 T168N mutant diffusion is confined by distinct actin nanodomains where conformational changes required for Janus-activated tyrosine kinase/signal transducer and activator of transcription (JAK/STAT) activation by IFN-γ could not occur. Removing IFN-γR2 T168N-bound galectins restored lateral diffusion in lipid nanodomains and JAK/STAT signaling in patient cells, whereas adding galectins impaired these processes in control cells. These experiments prove the critical role of dynamic receptor interactions with actin and lipid nanodomains and reveal a new function for receptor glycosylation and galectins. Our study establishes the physiological relevance of membrane nanodomains in the control of transmembrane receptor signaling in vivo. VIDEO ABSTRACT. PMID:27499022

  19. STS-1 promotes IFN-α induced autophagy by activating the JAK1-STAT1 signaling pathway in B cells.

    PubMed

    Dong, Guanjun; You, Ming; Fan, Hongye; Ding, Liang; Sun, Lingyun; Hou, Yayi

    2015-08-01

    Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the overexpression of IFN-α. IFN-α induces autophagy via the JAK1-STAT1 signaling pathway, contributing to the pathogenesis of SLE. Recent studies reported that B cells from patients with SLE and NZB/W F1 mice had enhanced autophagy activity; however, the mechanism still remains unknown. Here, we show that the protein tyrosine phosphatase STS-1 (suppressor of T-cell receptor signaling 1) was significantly overexpressed in B cells from patients with SLE and MRL/lpr mice. Notably, STS-1 promoted IFN-α-induced autophagy in B cells by enhancing the JAK1-STAT1 signaling activation. STS-1 inhibited the phosphorylation of the E3 ubiquitin protein ligase c-cbl, and subsequently promoted IFN-α-induced phosphorylation of tyrosine kinase 2, leading to JAK1-STAT1 signaling activation. Furthermore, STAT1 and JAK1 inhibitors blocked the IFN-α-induced autophagy promoted by STS-1, indicating that STS-1 promotes IFN-α-induced autophagy via the JAK1-STAT1 signaling. Our results demonstrate the importance of STS-1 in regulating IFN-α-induced autophagy in B cells, and this could be used as a therapeutic approach to treat SLE. PMID:25959715

  20. NK-DC crosstalk controls the autopathogenic Th17 response through an innate IFN-γ-IL-27 axis.

    PubMed

    Chong, Wai Po; van Panhuys, Nicholas; Chen, Jun; Silver, Phyllis B; Jittayasothorn, Yingyos; Mattapallil, Mary J; Germain, Ronald N; Caspi, Rachel R

    2015-09-21

    IFN-γ is a pathogenic cytokine involved in inflammation. Paradoxically, its deficiency exacerbates experimental autoimmune encephalomyelitis, uveitis, and arthritis. Here, we demonstrate using IFN-γ(-/-) mice repleted with IFN-γ +/+: NK cells that innate production of IFN-γ from NK cells is necessary and sufficient to trigger an endogenous regulatory circuit that limits autoimmunity. After immunization, DCs recruited IFN-γ-producing NK cells to the draining lymph node and interacted with them in a CXCR3-dependent fashion. The interaction caused DCs to produce IL-27, which in turn enhanced IFN-γ production by NK cells, forming a self-amplifying positive feedback loop. IL-10, produced by the interacting cells themselves, was able to limit this process. The NK-DC-dependent IL-27 inhibited development of the adaptive pathogenic IL-17 response and induced IL-10-producing Tr1-like cells, which ameliorated disease in an IL-10-dependent manner. Our data reveal that an early NK-DC interaction controls the adaptive Th17 response and limits tissue-specific autoimmunity through an innate IFN-γ-IL-27 axis. PMID:26347474

  1. Serum levels of IFN-β are associated with days of evolution but not with severity of dengue.

    PubMed

    Pech Torres, Ramón Enrique; Cedillo Rivera, Roberto Manuel; Loroño Pino, Maria Alba; Sánchez Burgos, Gilma Guadalupe

    2016-03-01

    The serum levels of beta interferon (IFN-β) were evaluated in clinical samples taken in the acute phase of dengue fever for 107 patients during the 2011 dengue outbreak in Yucatán, México. Dengue diagnoses were confirmed by NS1 or IgM/IgG serology in all patients. Average serum IFN-β levels in patients with dengue fever without warning signs (n = 53) were 140 pg/ml, and 105 pg/ml for patients with warning signs (n = 54). There was no statistically significant difference between IFN-β levels for the two groups (Mann-Whitney U Test P > 0.05) and no association with warning or mild signs (OR: 0.57; 95%CI: 0.26-1.22) was indicated. Thrombocytopenia was the most prevalent warning sign (91%) in one group of patients (49) with mean 113 pg/ml IFN-β levels. In contrast, the patients without thrombocytopenia (50) had 126 pg/ml of IFN-β, but this level was not statistically significant (Mann-Whitney U Test P > 0.05). The average levels of IFN-β were also found to have statistically similar results, using the 1997 WHO classification system. The amount of IFN-β at 1-3, 4-6, and 7-9 days after onset of illness, however, did show significant differences (ANOVA P = 0.038) between patients for the 1-3 and 4-6 days pair (Scheffe post-hoc P = 0.043). These results suggest that serum levels of IFN-β do not correlate well with the severity of dengue illness, but there is a clear association between changes in IFN-β levels and the days of evolution during the acute phase of the disease. PMID:26252251

  2. Natural Killer Cells-Produced IFN-γ Improves Bone Marrow-Derived Hepatocytes Regeneration in Murine Liver Failure Model

    PubMed Central

    Li, Lu; Zeng, Zhutian; Qi, Ziping; Wang, Xin; Gao, Xiang; Wei, Haiming; Sun, Rui; Tian, Zhigang

    2015-01-01

    Bone-marrow transplantation (BMT) can repopulate the liver through BM-derived hepatocyte (BMDH) generation, although the underlying mechanism remains unclear. Using fumarylacetoacetate hydrolase–deficient (Fah−/−) mice as a liver-failure model, we confirmed that BMDHs were generated by fusion of BM-derived CD11b+F4/80+myelomonocytes with resident Fah−/− hepatocytes. Hepatic NK cells became activated during BMDH generation and were the major IFN-γ producers. Indeed, both NK cells and IFN-γ were required for BMDH generation since WT, but not NK-, IFN-γ–, or IFN-γR1–deficient BM transplantation successfully generated BMDHs and rescued survival in Fah−/− hosts. BM-derived myelomonocytes were determined to be the IFN-γ–responding cells. The IFN-γ–IFN-γR interaction contributed to the myelomonocyte–hepatocyte fusion process, as most of the CD11b+ BMDHs in mixed BM chimeric Fah−/− hosts transplanted with a 1:1 ratio of CD45.1+ WT and CD45.2+ Ifngr1−/− BM cells were of CD45.1+ WT origin. Confirming these findings in vitro, IFN-γ dose-dependently promoted the fusion of GFP+ myelomonocytes with Fah−/− hepatocytes due to a direct effect on myelomonocytes; similar results were observed using activated NK cells. In conclusion, BMDH generation requires NK cells to facilitate myelomonocyte–hepatocyte fusion in an IFN-γ–dependent manner, providing new insights for treating severe liver failure. PMID:26345133

  3. Role of the IFN I system against the VHSV infection in juvenile Senegalese sole (Solea senegalensis).

    PubMed

    Alvarez-Torres, Daniel; Podadera, Ana M; Bejar, Julia; Bandin, Isabel; Alonso, M Carmen; Garcia-Rosado, Esther

    2016-01-01

    Senegalese sole is susceptible to marine VHSV isolates but is not affected by freshwater isolates, which may indicate differences regarding virus-host immune system interaction. IFN I induces an antiviral state in fish, stimulating the expression of genes encoding antiviral proteins (ISG). In this study, the stimulation of the Senegalese sole IFN I by VHSV infections has been evaluated by the relative quantification of the transcription of several ISG (Mx, Isg15 and Pkr) after inoculation with marine (pathogenic) and freshwater (non-pathogenic) VHSV isolates. Compared to marine VHSV, lower levels of RNA of the freshwater VHSV induced transcription of ISG to similar levels, with the Isg15 showing the highest fold induction. The protective role of the IFN I system was evaluated in poly I:C-inoculated animals subsequently challenged with VHSV isolates. The cumulative mortality caused by the marine isolate in the control group was 68%, whereas in the poly I:C-stimulated group was 5%. The freshwater VHSV isolate did not cause any mortality. Furthermore, viral RNA fold change and viral titers were lower in animals from the poly I:C + VHSV groups than in the controls. The implication of the IFN I system in the protection observed was confirmed by the transcription of the ISG in animals from the poly I:C + VHSV groups. However, the marine VHSV isolate exerts a negative effect on the ISG transcription at 3 and 6 h post-inoculation (hpi), which is not observed for the freshwater isolate. This difference might be partly responsible for the virulence shown by the marine isolate. PMID:26743229

  4. Molecular characterization of RIG-I, STAT-1 and IFN-beta in the horseshoe bat.

    PubMed

    Li, Jinju; Zhang, Guangxu; Cheng, Dalong; Ren, Hua; Qian, Min; Du, Bing

    2015-04-25

    Wild Chinese horseshoe bats have been proven to be natural reservoirs of SARS-like coronaviruses. However, the molecular characterization of key proteins in bats still needs to be explored further. In this study, we used cloning and bioinformatics to analyze the sequence of RIG-I, STAT-1 and IFN-β in the immortalized cell lines from Rhinolophus affinis and Rhinolophus sinicus. Then, we treated different bat cells, mouse embryonic fibroblasts (MEF) and splenocytes with polyinosinic-polycytidylic acid (polyI:C) and vesicular stomatitis virus (VSV) to assess and compare antiviral immune responses between bats and mice. Our results demonstrated that bat RIG-I, STAT-1 and IFN-β showed close homology with human, mouse, pig and rhesus monkey. RIG-I and STAT-1 were both highly expressed in bat spleen. Furthermore, IFN-β was induced by polyI:C and VSV in both bat and mouse cells. These findings have provided new insight into the potential characteristics of the bat innate immune system against viral infection. PMID:25680291

  5. Probiotic Leuconostoc mesenteroides ssp. cremoris and Streptococcus thermophilus induce IL-12 and IFN-γ production

    PubMed Central

    Kekkonen, Riina A; Kajasto, Elina; Miettinen, Minja; Veckman, Ville; Korpela, Riitta; Julkunen, Ilkka

    2008-01-01

    AIM: To investigate the capacity of potentially probiotic strains from six bacterial genera to induce cytokine production alone or in combinations in order to identify potential enhancing or synergistic effects in order to select probiotic bacteria for in vivo purposes. METHODS: Cytokine production in human peripheral blood mononuclear cells (PBMC) in response to stimulation with eleven different potentially probiotic bacterial strains from Streptococcus, Lactobacillus, Bifidobacterium, Lactococcus, Leuconostoc and Propionibacterium genera was analysed. Production and mRNA expression of TNF-α, IL-12, IFN-γ and IL-10 were determined by ELISA and Northern blotting, respectively. RESULTS: All tested bacteria induced TNF-α production. The best inducers of Th1 type cytokines IL-12 and IFN-γ were Streptococcus and Leuconostoc strains. All Bifidobacterium and Propionibacterium strains induced higher IL-10 production than other studied bacteria. Stimulation of PBMC with any bacterial combinations did not result in enhanced cytokine production suggesting that different bacteria whether gram-positive or gram-negative compete with each other during host cell interactions. CONCLUSION: The probiotic S. thermophilus and Leuconostoc strains are more potent inducers of Th1 type cytokines IL-12 and IFN-γ than the probiotic Lactobacillus strains. Bacterial combinations did not result in enhanced cytokine production. PMID:18300344

  6. Vitamin D Is Required for IFN-γ–Mediated Antimicrobial Activity of Human Macrophages

    PubMed Central

    Fabri, Mario; Stenger, Steffen; Shin, Dong-Min; Yuk, Jae-Min; Liu, Philip T.; Realegeno, Susan; Lee, Hye-Mi; Krutzik, Stephan R.; Schenk, Mirjam; Sieling, Peter A.; Teles, Rosane; Montoya, Dennis; Iyer, Shankar S.; Bruns, Heiko; Lewinsohn, David M.; Hollis, Bruce W.; Hewison, Martin; Adams, John S.; Steinmeyer, Andreas; Zügel, Ulrich; Cheng, Genhong; Jo, Eun-Kyeong; Bloom, Barry R.; Modlin, Robert L.

    2012-01-01

    Control of tuberculosis worldwide depends on our understanding of human immune mechanisms, which combat the infection. Acquired T cell responses are critical for host defense against microbial pathogens, yet the mechanisms by which they act in humans remain unclear. We report that T cells, by the release of interferon-γ (IFN-γ), induce autophagy, phagosomal maturation, the production of antimicrobial peptides such as cathelicidin, and antimicrobial activity against Mycobacterium tuberculosis in human macrophages via a vitamin D–dependent pathway. IFN-γ induced the antimicrobial pathway in human macrophages cultured in vitamin D–sufficient sera, but not in sera from African-Americans that have lower amounts of vitamin D and who are more susceptible to tuberculosis. In vitro supplementation of vitamin D–deficient serum with 25-hydroxyvitamin D3 restored IFN-γ–induced antimicrobial peptide expression, autophagy, phagosome-lysosome fusion, and antimicrobial activity. These results suggest a mechanism in which vitamin D is required for acquired immunity to overcome the ability of intracellular pathogens to evade macrophage-mediated antimicrobial responses. The present findings underscore the importance of adequate amounts of vitamin D in all human populations for sustaining both innate and acquired immunity against infection. PMID:21998409

  7. Recombinant LPG3 Stimulates IFN-Γ and TNF-A Secretion by Human NK Cells

    PubMed Central

    RASOLZADEH, Sanaz; HAJI FATAHALIHA, Mostafa; HOSSEINI, Maryam; JAFARI, Reza; MIAHIPOUR, Abolfazl; MOVASSAGHPOUR, Ali Akbar; BABALO, Zohreh; RAFATI, Sima; YOUSEFI, Mehdi

    2015-01-01

    Background: Natural killer (NK) cells play an important role in early stages of innate immune responses against viral and tumoral attacks. Activation of NK cells by leishmaniasis results in secretion of cytokines such as interferon (IFN)-γ and tumor necrosis factor (TNF)-α, which enhances the phagocytosis and clearance of parasite. Lipophosphoglycan 3 (LPG3), the Leishmania homologous with GRP94 (glucose regulated protein 94), a member of HSP90 family, contributes to LPG assembly as the most abundant macromolecule on the surface of Leishmania promastigotes. Methods: We purified NK cells from healthy individuals (n=10) using magnetic-activated cell sorting (MACS) technology. Purified NK cells were co-incubated with different concentrations of recombinant LPG3 (rLPG3), and its N-terminal (NT) and C-terminal (CT) fragments. Finally, the production of IFN-γ and TNF-α by NK cells were measured by ELISA. Results: Recombinant LPG3 but not its fragments (CT and NT), can significantly enhance the production of TNF-α by NK cells (P<0.05). Moreover, rLPG3, CT, and NT fragments were markedly stimulated the secretion of IFN-γ by NK cells (P<0.001). Conclusion: The Leishmania LPG3 antigen can effectively activate NK cells, in vitro. Leishmania LPG3 participates in the innate immunity against leishmaniasis and thereby improves the effective parasite destruction. However, its efficiency should be tested in vivo. PMID:26811721

  8. Recombinant LPG3 Stimulates IFN-Γ and TNF-Α Secretion by Human NK Cells

    PubMed Central

    RASOLZADEH, Sanaz; HAJI FATAHALIHA, Mostafa; HOSSEINI, Maryam; JAFARI, Reza; MIAHIPOUR, Abolfazl; SADREDDINI, Sevil; BABALO, Zohreh; SAMADI KAFIL, Hossein; YOUSEFI, Mehdi

    2015-01-01

    Background: Natural killer (NK) cells play an important role in early stages of innate immune responses against viral and tumoral attacks. Activation of NK cells by leishmaniasis results in secretion of cytokines such as interferon (IFN)-γ and tumor necrosis factor (TNF)-α, which enhance the phagocytosis and clearance of parasite. Lipophosphoglycan 3 (LPG3), the Leishmania homologous with GRP94 (glucose regulated protein 94), a member of HSP90 family, contributes to LPG assembly as the most abundant macromolecule on the surface of Leishmania promastigotes. Methods: We purified NK cells from healthy individuals (n=10) using magnetic-activated cell sorting (MACS) technology. Purified NK cells were co-incubated with different concentrations of recombinant LPG3 (rLPG3), and its N-terminal (NT) and C-terminal (CT) fragments. Finally, the production of IFN-γ and TNF-α by NK cells were measured by ELISA. Results: Recombinant LPG3 but not its fragments (CT and NT), could significantly enhance the production of TNF-α by NK cells (P<0.05). Moreover, rLPG3, CT, and NT fragments were markedly stimulated the secretion of IFN-γ by NK cells (P<0.001). Conclusion: The Leishmania LPG3 antigen could effectively activate NK cells, in vitro. Leishmania LPG3 participates in the innate immunity against leishmaniasis and thereby improves the effective parasite destruction. However, its efficiency should be tested in vivo. PMID:26622301

  9. Type I IFNs induce anti-tumor polarization of tumor associated neutrophils in mice and human.

    PubMed

    Andzinski, Lisa; Kasnitz, Nadine; Stahnke, Stephanie; Wu, Ching-Fang; Gereke, Marcus; von Köckritz-Blickwede, Maren; Schilling, Bastian; Brandau, Sven; Weiss, Siegfried; Jablonska, Jadwiga

    2016-04-15

    The importance of tumor associated neutrophils (TANs) in cancer development is in the meantime well established. Numerous of clinical data document the adverse prognostic effects of neutrophil infiltration in solid tumors. However, certain tumor therapies need functional neutrophils to be effective, suggesting altered neutrophil polarization associated with different outcomes for cancer patients. Therefore, modulation of neutrophilic phenotypes represents a potent therapeutic option, but factors mediating neutrophil polarization are still poorly defined. In this manuscript we provide evidence that type I IFNs alter neutrophilic phenotype into anti-tumor, both in mice and human. In the absence of IFN-β, pro-tumor properties, such as reduced tumor cytotoxicity with low neutrophil extracellular traps (NETs) expression, low ICAM1 and TNF-α expression, dominated neutrophil phenotypes in primary lesion and premetastatic lung. Interestingly, such neutrophils have significantly prolonged life-span. Notably, interferon therapy in mice altered TAN polarization towards anti-tumor N1. Similar changes in neutrophil activation could be observed in melanoma patients undergoing type I IFN therapy. Altogether, these data highlight the therapeutic potential of interferons, suggesting optimization of its clinical use as potent anti-tumor agent. PMID:26619320

  10. Genetic polymorphisms, their allele combinations and IFN-β treatment response in Irish multiple sclerosis patients

    PubMed Central

    O’Doherty, Catherine; Favorov, Alexander; Heggarty, Shirley; Graham, Colin; Favorova, Olga; Ochs, Michael; Hawkins, Stanley; Hutchinson, Michael; O’Rourke, Killian; Vandenbroeck, Koen

    2009-01-01

    Introduction IFN-β is widely used as first-line immunomodulatory treatment for multiple sclerosis. Response to treatment is variable (30–50% of patients are nonresponders) and requires a long treatment duration for accurate assessment to be possible. Information about genetic variations that predict responsiveness would allow appropriate treatment selection early after diagnosis, improve patient care, with time saving consequences and more efficient use of resources. Materials & methods We analyzed 61 SNPs in 34 candidate genes as possible determinants of IFN-β response in Irish multiple sclerosis patients. Particular emphasis was placed on the exploration of combinations of allelic variants associated with response to therapy by means of a Markov chain Monte Carlo-based approach (APSampler). Results The most significant allelic combinations, which differed in frequency between responders and nonresponders, included JAK2–IL10RB–GBP1–PIAS1 (permutation p-value was pperm = 0.0008), followed by JAK2–IL10–CASP3 (pperm = 0.001). Discussion The genetic mechanism of response to IFN-β is complex and as yet poorly understood. Data mining algorithms may help in uncovering hidden allele combinations involved in drug response versus nonresponse. PMID:19604093

  11. Key Role of Splenic Myeloid DCs in the IFN-αβ Response to Adenoviruses In Vivo

    PubMed Central

    Fejer, György; Drechsel, Lisa; Liese, Jan; Schleicher, Ulrike; Ruzsics, Zsolt; Imelli, Nicola; Greber, Urs F.; Keck, Simone; Hildenbrand, Bernd; Krug, Anne; Bogdan, Christian; Freudenberg, Marina A.

    2008-01-01

    The early systemic production of interferon (IFN)-αβ is an essential component of the antiviral host defense mechanisms, but is also thought to contribute to the toxic side effects accompanying gene therapy with adenoviral vectors. Here we investigated the IFN-αβ response to human adenoviruses (Ads) in mice. By comparing the responses of normal, myeloid (m)DC- and plasmacytoid (p)DC-depleted mice and by measuring IFN-αβ mRNA expression in different organs and cells types, we show that in vivo, Ads elicit strong and rapid IFN-αβ production, almost exclusively in splenic mDCs. Using knockout mice, various strains of Ads (wild type, mutant and UV-inactivated) and MAP kinase inhibitors, we demonstrate that the Ad-induced IFN-αβ response does not require Toll-like receptors (TLR), known cytosolic sensors of RNA (RIG-I/MDA-5) and DNA (DAI) recognition and interferon regulatory factor (IRF)-3, but is dependent on viral endosomal escape, signaling via the MAP kinase SAPK/JNK and IRF-7. Furthermore, we show that Ads induce IFN-αβ and IL-6 in vivo by distinct pathways and confirm that IFN-αβ positively regulates the IL-6 response. Finally, by measuring TNF-α responses to LPS in Ad-infected wild type and IFN-αβR−/− mice, we show that IFN-αβ is the key mediator of Ad-induced hypersensitivity to LPS. These findings indicate that, like endosomal TLR signaling in pDCs, TLR-independent virus recognition in splenic mDCs can also produce a robust early IFN-αβ response, which is responsible for the bulk of IFN-αβ production induced by adenovirus in vivo. The signaling requirements are different from known TLR-dependent or cytosolic IFN-αβ induction mechanisms and suggest a novel cytosolic viral induction pathway. The hypersensitivity to components of the microbial flora and invading pathogens may in part explain the toxic side effects of adenoviral gene therapy and contribute to the pathogenesis of adenoviral disease. PMID:19008951

  12. Kinetics of IFN-Gamma and TNF-Alpha Gene Expression and Their Relationship with Disease Progression after Infection with Mycobacterium Tuberculosis in Guinea Pigs

    PubMed Central

    Roh, In Soon; Cho, Sungae; Eum, Seok-Yong

    2013-01-01

    Purpose Guinea pig is one of the most suitable animal models for Mycobacterium tuberculosis (M. tb) infection since it shows similarities to pulmonary infection in humans. Although guinea pig shows hematogenous spread of M. tb infection into the whole body, immunological studies have mainly focused on granulomatous tissues in lungs and spleens. In order to investigate the time-course of disease pathogenesis and immunological profiles in each infected organ, we performed the following approaches with guinea pigs experimentally infected with M. tb over a 22-week post-infection period. Materials and Methods We examined body weight changes, M. tb growth curve, cytokine gene expression (IFN-γ and TNF-α), and histopathology in liver, spleen, lungs and lymph nodes of infected guinea pigs. Results The body weights of infected guinea pigs did not increase as much as uninfected ones and the number of M. tb bacilli in their organs increased except bronchotracheal lymph node during the experimental period. The gene expression of IFN-γ and TNF-α was induced between 3 and 6 weeks of infection; however, kinetic profiles of cytokine gene expression showed heterogeneity among organs over the study period. Histophathologically granulomatous lesions were developed in all four organs of infected guinea pigs. Conclusion Although IFN-γ and TNF-α gene expression profiles showed heterogeneity, the granuloma formation was clearly observed in every organ regardless of whether the number of bacilli increased or decreased. However, this protective immunity was accompanied with severe tissue damage in all four organs, which may lead to the death of guinea pigs. PMID:23549819

  13. IL-7 Promotes CD95-Induced Apoptosis in B Cells via the IFN-γ/STAT1 Pathway

    PubMed Central

    Sammicheli, Stefano; Dang Vu Phuong, Linh; Ruffin, Nicolas; Pham Hong, Thang; Lantto, Rebecka; Vivar, Nancy; Chiodi, Francesca; Rethi, Bence

    2011-01-01

    Interleukin-7 (IL-7) concentrations are increased in the blood of CD4+ T cell depleted individuals, including HIV-1 infected patients. High IL-7 levels might stimulate T cell activation and, as we have shown earlier, IL-7 can prime resting T cell to CD95 induced apoptosis as well. HIV-1 infection leads to B cell abnormalities including increased apoptosis via the CD95 (Fas) death receptor pathway and loss of memory B cells. Peripheral B cells are not sensitive for IL-7, due to the lack of IL-7Ra expression on their surface; however, here we demonstrate that high IL-7 concentration can prime resting B cells to CD95-mediated apoptosis via an indirect mechanism. T cells cultured with IL-7 induced high CD95 expression on resting B cells together with an increased sensitivity to CD95 mediated apoptosis. As the mediator molecule responsible for B cell priming to CD95 mediated apoptosis we identified the cytokine IFN-γ that T cells secreted in high amounts in response to IL-7. These results suggest that the lymphopenia induced cytokine IL-7 can contribute to the increased B cell apoptosis observed in HIV-1 infected individuals. PMID:22194871

  14. Interferon-γ is increased in the gut of patients with irritable bowel syndrome and modulates serotonin metabolism.

    PubMed

    Barbaro, Maria Raffaella; Di Sabatino, Antonio; Cremon, Cesare; Giuffrida, Paolo; Fiorentino, Michelangelo; Altimari, Annalisa; Bellacosa, Lara; Stanghellini, Vincenzo; Barbara, Giovanni

    2016-03-15

    Mucosal immune activation and altered serotonin metabolism participate in the pathophysiology of irritable bowel syndrome (IBS). However, the reciprocal interplay between these two systems remains unknown. We evaluated the expression and release of interferon (IFN)-γ from the colonic mucosa of patients with IBS and its impact on serotonin reuptake transporter (SERT) gene expression in Caco-2 cells. qPCR was used to evaluate IFN-γ gene expression in colonic mucosal biopsies, whereas IFN-γ protein amount was assessed by ELISA. Colonic T box expressed in T cells (T-bet) and phosphorylated signal transducer and activator of transcription 4 protein amount were evaluated by Western blot. The impact of colonic mucosal mediators on SERT gene expression was evaluated in Caco-2 cells using qPCR. IFN-γ receptor was silenced in Caco-2 cells to determine the effect of IFN-γ released by mucosal biopsies. Compared with asymptomatic controls (ACs), the expression of IFN-γ gene and its transcription factor T-bet were markedly increased in the colonic mucosa of patients with IBS. Compared with ACs, IFN-γ protein tissue levels and its release by mucosal biopsies were significantly increased in IBS. The exposure of Caco-2 cells to IBS supernatants induced a significant decrease in SERT gene expression, independently of IBS subtypes, compared with AC mucosal supernatants. In Caco-2 cells, IFN-γ receptor silencing reversed the reduction of SERT expression evoked by IBS supernatants vs. nonsilenced cell lines. IFN-γ gene, its transcription factor T-bet, IFN-γ protein expression, and its release are increased in the colonic mucosa of patients with IBS and downregulate SERT gene expression in vitro. These results suggest that IFN-γ downregulates SERT expression, hence likely playing a role in altered serotonin metabolism of patients with IBS. PMID:26744473

  15. Cerebral and ocular toxoplasmosis related with IFN-γ, TNF-α, and IL-10 levels

    PubMed Central

    Meira, Cristina S.; Pereira-Chioccola, Vera L.; Vidal, José E.; de Mattos, Cinara C. Brandão; Motoie, Gabriela; Costa-Silva, Thais A.; Gava, Ricardo; Frederico, Fábio B.; de Mattos, Luiz C.

    2014-01-01

    This study analyzed the synthesis of Interferon gamma (IFN-γ), Tumor Necrosis Factor alpha (TNF-α), and Interleukin 10 (IL-10) in chronically infected patients which developed the symptomatic disease as cerebral or ocular toxoplasmosis. Blood from 61 individuals were divided into four groups: Cerebral toxoplasmosis/AIDS patients (CT/AIDS group) (n = 15), ocular toxoplasmosis patients (OT group) (n = 23), chronic toxoplasmosis individuals (CHR group) (n = 13) and healthy individuals (HI group) (n = 10). OT, CHR, and HI groups were human immunodeficiency virus (HIV) seronegative. The diagnosis was made by laboratorial (PCR and ELISA) and clinical subjects. For cytokine determination, peripheral blood mononuclear cells (PBMC) of each patient were isolated and stimulated in vitro with T. gondii antigen. IFN-γ, TNF-α, and IL-10 activities were determined by ELISA. Patients from CT/AIDS and OT groups had low levels of IFN-γ when were compared with those from CHR group. These data suggest the low resistance to develop ocular lesions by the low ability to produce IFN-γ against the parasite. The same patients, which developed ocular or cerebral toxoplasmosis had higher TNF-α levels than CHR individuals. High TNF-α synthesis contribute to the inflammatory response and damage of the choroid and retina in OT patients and in AIDS patients caused a high inflammatory response as the TNF-α synthesis is not affected since monocytes are the major source this cytokine in response to soluble T. gondii antigens. IL-10 levels were almost similar in CT/AIDS and OT patients but low when compared with CHR individuals. The deviation to Th2 immune response including the production of anti-inflammatory cytokines, such as IL-10 may promote the parasite's survival causing the tissue immune destruction. IL-10 production in T. gondii-infected brains may support the persistence of parasites as down-regulating the intracerebral immune response. All these indicate that OT and CT

  16. Revisiting the Heterogeneous IFN-γ Response of Bacille of Calmette-Guérin (BCG)-Revaccinated Healthy Volunteers in a Randomized Controlled Trial: Effect of the Body Mass Index and of the IFNG+874 A/T Polymorphism

    PubMed Central

    Conceição, Elisabete L.; Nascimento-Sampaio, Francisco S.; Schwingel, Paulo A.; Oliveira, Evelin S.; Rocha, Michael S.; Vieira, Igor; Mendes, Carlos M. C.; Souza-Machado, Adelmir; Oliveira, Martha M.; Barral-Netto, Manoel; Marinho, Jamocyr M.

    2016-01-01

    In trials evaluating the immune responses to Bacille of Calmette-Guérin (BCG), the genetic background and the nutritional status are host-related factors that could affect the heterogeneity in these parameters. The IFNG+874 A/T (rs 62559044) polymorphism has been reported to influence the IFN-γ production by BCG-vaccinated individuals challenged in vitro with mycobacterial antigens. The body mass index (BMI) is a proxy for the nutritional status and has been associated both with the susceptibility to tuberculosis and with the IFN-γ response. We show that although the IFNG+874 A/T polymorphism was not associated with the heterogeneity of IFN-γ production in a randomized controlled trial that evaluated long-term immune responses to BCG revaccination previously conducted in Salvador, Bahia, Brazil, the effect of this polymorphism on the observed increase in IFN-γ production among revaccinated subjects was adjusted in individuals with a low BMI. PMID:27472280

  17. Characterization of lethal dengue virus type 4 (DENV-4) TVP-376 infection in mice lacking both IFN-α/β and IFN-γ receptors (AG129) and comparison with the DENV-2 AG129 mouse model.

    PubMed

    Sarathy, Vanessa V; Infante, Ernesto; Li, Li; Campbell, Gerald A; Wang, Tian; Paessler, Slobodan; Robert Beatty, P; Harris, Eva; Milligan, Gregg N; Bourne, Nigel; Barrett, Alan D T

    2015-10-01

    Dengue is a mosquito-borne disease caused by four related but distinct dengue viruses, DENV-1 to DENV-4. Dengue is endemic in most tropical countries, and over a third of the world's population is at risk of being infected. Although the global burden is high, no vaccine or antiviral is licensed to combat this disease. An obstacle complicating dengue research is the lack of animal challenge models that mimic human disease. Advances in immunocompromised murine infection models resulted in development of lethal DENV-2, DENV-3 and DENV-4 models in AG129 mice, which are deficient in both the IFN-α/β receptor (IFN-α/βR) and the IFN-γ receptor (IFN-γR). These models mimic features of dengue disease in humans. Here, we characterized lethal infection of AG129 mice by DENV-4 strain TVP-376 and found that AG129 mice developed clinical signs of illness and high viral loads in multiple tissues and succumbed 5 days after infection. Moreover, the splenic and hepatic histopathology of TVP-376-infected mice demonstrated the presence of cell activation and destruction of tissue architecture. Furthermore, infected mice had heightened levels of circulating cytokines. Comparison of the virulence phenotypes of DENV-4 strain TVP-376 and DENV-2 strain D2S10 revealed that TVP-376-induced mortality occurred in the absence of both IFN-α/βR and IFN-γR signalling, but not with intact signalling from the IFN-γR, whereas D2S10 required the absence of IFN-α/βR signalling only, indicating that it is more virulent than TVP-376. In conclusion, TVP-376 is lethal in AG129 mice, and this model provides a useful platform to investigate vaccine candidates and antivirals against DENV-4. PMID:26296350

  18. Interferon (IFN) Consensus Sequence-binding Protein, a Transcription Factor of the IFN Regulatory Factor Family, Regulates Immune Responses In Vivo through Control of Interleukin 12 Expression

    PubMed Central

    Giese, Nathalia A.; Gabriele, Lucia; Doherty, T. Mark; Klinman, Dennis M.; Tadesse-Heath, Lekidelu; Contursi, Christina; Epstein, Suzanne L.; Morse, Herbert C.

    1997-01-01

    Mice with a null mutation of the gene encoding interferon consensus sequence-binding protein (ICSBP) develop a chronic myelogenous leukemia-like syndrome and mount impaired responses to certain viral and bacterial infections. To gain a mechanistic understanding of the contributions of ICSBP to humoral and cellular immunity, we characterized the responses of control and ICSBP−/− mice to infection with influenza A (flu) and Leishmania major (L. major). Mice of both genotypes survived infections with flu, but differed markedly in the isotype distribution of antiflu antibodies. In sera of normal mice, immunoglobulin (Ig)G2a antibodies were dominant over IgG1 antibodies, a pattern indicative of a T helper cell type 1 (Th1)-driven response. In sera of ICSBP−/− mice, however, IgG1 antibodies dominated over IgG2a antibodies, a pattern indicative of a Th2-driven response. The dominance of IgG1 and IgE over IgG2a was detected in the sera of uninfected mice as well. A seeming Th2 bias of ICSBP-deficient mice was also uncovered in their inability to control infection with L. major, where resistance is known to be dependent on IL-12 and IFN-γ as components of a Th1 response. Infected ICSBP-deficient mice developed fulminant, disseminated leishmaniasis as a result of failure to mount a Th1-mediated curative response, although T cells remained capable of secreting IFN-γ and macrophages of producing nitric oxide. Compromised Th1 differentiation in ICSBP−/− mice could not be attributed to hyporesponsiveness of CD4+ T cells to interleukin (IL)-12; however, the ability of uninfected and infected ICSBP-deficient mice to produce IL-12 was markedly impaired. This indicates that ICSBP is a deciding factor in Th responses governing humoral and cellular immunity through its role in regulating IL-12 expression. PMID:9348311

  19. Lnk/Sh2b3 controls the production and function of dendritic cells and regulates the induction of IFN-γ-producing T cells.

    PubMed

    Mori, Taizo; Iwasaki, Yukiko; Seki, Yoichi; Iseki, Masanori; Katayama, Hiroko; Yamamoto, Kazuhiko; Takatsu, Kiyoshi; Takaki, Satoshi

    2014-08-15

    Dendritic cells (DCs) are proficient APCs that play crucial roles in the immune responses to various Ags and pathogens and polarize Th cell immune responses. Lnk/SH2B adaptor protein 3 (Sh2b3) is an intracellular adaptor protein that regulates B lymphopoiesis, megakaryopoiesis, and expansion of hematopoietic stem cells by constraining cytokine signals. Recent genome-wide association studies have revealed a link between polymorphism in this adaptor protein and autoimmune diseases, including type 1 diabetes and celiac disease. We found that Lnk/Sh2b3 was also expressed in DCs and investigated its role in the production and function of DC lineage cells. In Lnk(-/-) mice, DC numbers were increased in the spleen and lymph nodes, and growth responses of bone marrow-derived DCs to GM-CSF were augmented. Mature DCs from Lnk(-/-) mice were hypersensitive and showed enhanced responses to IL-15 and GM-CSF. Compared to normal DCs, Lnk(-/-) DCs had enhanced abilities to support the differentiation of IFN-γ-producing Th1 cells from naive CD4(+) T cells. This was due to their elevated expression of IL-12Rβ1 and increased production of IFN-γ. Lnk(-/-) DCs supported the appearance of IFN-γ-producing T cells even under conditions in which normal DCs supported induction of regulatory T cells. These results indicated that Lnk/Sh2b3 plays a regulatory role in the expansion of DCs and might influence inflammatory immune responses in peripheral lymphoid tissues. PMID:25024389

  20. Harnessing Mechanistic Knowledge on Beneficial Versus Deleterious IFN-I Effects to Design Innovative Immunotherapies Targeting Cytokine Activity to Specific Cell Types

    PubMed Central

    Tomasello, Elena; Pollet, Emeline; Vu Manh, Thien-Phong; Uzé, Gilles; Dalod, Marc

    2014-01-01

    Type I interferons (IFN-I) were identified over 50 years ago as cytokines critical for host defense against viral infections. IFN-I promote anti-viral defense through two main mechanisms. First, IFN-I directly reinforce or induce de novo in potentially all cells the expression of effector molecules of intrinsic anti-viral immunity. Second, IFN-I orchestrate innate and adaptive anti-viral immunity. However, IFN-I responses can be deleterious for the host in a number of circumstances, including secondary bacterial or fungal infections, several autoimmune diseases, and, paradoxically, certain chronic viral infections. We will review the proposed nature of protective versus deleterious IFN-I responses in selected diseases. Emphasis will be put on the potentially deleterious functions of IFN-I in human immunodeficiency virus type 1 (HIV-1) infection, and on the respective roles of IFN-I and IFN-III in promoting resolution of hepatitis C virus (HCV) infection. We will then discuss how the balance between beneficial versus deleterious IFN-I responses is modulated by several key parameters including (i) the subtypes and dose of IFN-I produced, (ii) the cell types affected by IFN-I, and (iii) the source and timing of IFN-I production. Finally, we will speculate how integration of this knowledge combined with advanced biochemical manipulation of the activity of the cytokines should allow designing innovative immunotherapeutic treatments in patients. Specifically, we will discuss how induction or blockade of specific IFN-I responses in targeted cell types could promote the beneficial functions of IFN-I and/or dampen their deleterious effects, in a manner adapted to each disease. PMID:25400632

  1. Expression of Interferon Lambda 4 Is Associated with Reduced Proliferation and Increased Cell Death in Human Hepatic Cells

    PubMed Central

    Onabajo, Olusegun O.; Porter-Gill, Patricia; Paquin, Ashley; Rao, Nina; Liu, Luyang; Tang, Wei; Brand, Nathan

    2015-01-01

    Interferon lambda 4 (IFN-λ4) is a novel type-III interferon that can be generated only in individuals carrying a ΔG frame-shift allele of an exonic genetic variant (rs368234815-ΔG/TT). The rs368234815-ΔG allele is strongly associated with decreased clearance of hepatitis C virus (HCV) infection. Here, we further explored the biological function of IFN-λ4 expressed in human hepatic cells—a hepatoma cell line HepG2 and fresh primary human hepatocytes (PHHs). We performed live confocal imaging, cell death and proliferation assays, mRNA expression profiling, protein detection, and antibody blocking assays using transient and inducible stable in vitro systems. Not only did we observe significant intracellular retention of IFN-λ4 but also detected secreted IFN-λ4 in the culture media of expressing cells. Secreted IFN-λ4 induced strong activation of the interferon-stimulated genes (ISGs) in IFN-λ4-expressing and surrounding cells in transwell assays. Specifically, in PHHs, secreted IFN-λ4 induced expression of the CXCL10 transcript and a corresponding pro-inflammatory chemokine, IP-10. In IFN-λ4-expressing HepG2 cells, we also observed decreased proliferation and increased cell death. All IFN-λ4-induced phenotypes—activation of ISGs, decreased proliferation, and increased cell death—could be inhibited by an anti-IFN-λ4-specific antibody. Our study offers new insights into biology of IFN-λ4 and its possible role in HCV clearance. PMID:26134097

  2. Pharmacodynamics of PEG-IFN alpha-2a in HIV/HCV co-infected patients: Implications for treatment outcomes

    PubMed Central

    Dahari, Harel; Affonso de Araujo, Evaldo S.; Haagmans, Bart L.; Layden, Thomas J.; Cotler, Scott J.; Barone, Antonio A.; Neumann, Avidan U.

    2010-01-01

    Background & Aims The pharmacokinetics and pharmacodynamics of pegylated-interferon-α-2a (PEG-IFN) have not been described in HCV/HIV co-infected patients. We sought to estimate the pharmacokinetics and pharmacodynamics of PEG-IFN and determine whether these parameters predict treatment outcome. Methods Twenty-six HCV/human immunodeficiency virus (HIV)-co-infected patients were treated with a 48-week regimen of PEG-IFN (180 µg/week) plus ribavirin (11 mg/kg/day). HCV-RNA and PEG-IFN concentrations were obtained from samples collected until week 12. A modeling framework that includes pharmacokinetic and pharmacodynamic parameters was developed. Results Five patients discontinued treatment. Seven patients achieved a sustained virological response (SVR). PEG-IFN concentrations at day 8 were similar to steady-state levels (p = 0.15) and overall pharmacokinetic parameters were similar in SVRs and non-SVRs. The maximum PEG-IFN effectiveness during the first PEG-IFN dose and the HCV-infected cell loss rate (δ), was significantly higher in SVRs compared to non-SVRs (median 95% vs 86% [p = 0.013], 0.27 vs 0.11 day−1 [p = 0.006], respectively). Patients infected with HCV genotype-1 had a significantly lower average first-week PEG-IFN effectiveness (median 70% vs. 88% [p = 0.043]), however, 4- to 12-week PEG-IFN effectiveness was not significantly different compared to those with genotype-3 (p = 0.114). Genotype-1 had a significantly lower δ compared to genotype-3 (median 0.14 vs. 0.23 day−1 [p = 0.021]). The PEG-IFN concentration that decreased HCV production by 50% (EC50) was lower in genotype-3 compared to genotype-1 (median 1.3 vs. 3.4 [p = 0.034]). Conclusions Both the HCV infected cell loss rate (δ) and the maximum effectiveness of the first dose of PEG-IFN-α-2a distinguished HIV co-infected patients and were highly predictive of SVR. Further studies are needed to validate these viral kinetic parameters as early on-treatment prognosticators of response in

  3. TLR-Mediated Innate Production of IFN-γ by CD8+ T Cells Is Independent of Glycolysis.

    PubMed

    Salerno, Fiamma; Guislain, Aurelie; Cansever, Dilay; Wolkers, Monika C

    2016-05-01

    CD8(+) T cells can respond to unrelated infections in an Ag-independent manner. This rapid innate-like immune response allows Ag-experienced T cells to alert other immune cell types to pathogenic intruders. In this study, we show that murine CD8(+) T cells can sense TLR2 and TLR7 ligands, resulting in rapid production of IFN-γ but not of TNF-α and IL-2. Importantly, Ag-experienced T cells activated by TLR ligands produce sufficient IFN-γ to augment the activation of macrophages. In contrast to Ag-specific reactivation, TLR-dependent production of IFN-γ by CD8(+) T cells relies exclusively on newly synthesized transcripts without inducing mRNA stability. Furthermore, transcription of IFN-γ upon TLR triggering depends on the activation of PI3K and serine-threonine kinase Akt, and protein synthesis relies on the activation of the mechanistic target of rapamycin. We next investigated which energy source drives the TLR-induced production of IFN-γ. Although Ag-specific cytokine production requires a glycolytic switch for optimal cytokine release, glucose availability does not alter the rate of IFN-γ production upon TLR-mediated activation. Rather, mitochondrial respiration provides sufficient energy for TLR-induced IFN-γ production. To our knowledge, this is the first report describing that TLR-mediated bystander activation elicits a helper phenotype of CD8(+) T cells. It induces a short boost of IFN-γ production that leads to a significant but limited activation of Ag-experienced CD8(+) T cells. This activation suffices to prime macrophages but keeps T cell responses limited to unrelated infections. PMID:27016606

  4. S1PR4 Signaling Attenuates ILT 7 Internalization To Limit IFN-α Production by Human Plasmacytoid Dendritic Cells.

    PubMed

    Dillmann, Christina; Ringel, Christian; Ringleb, Julia; Mora, Javier; Olesch, Catherine; Fink, Annika F; Roberts, Edward; Brüne, Bernhard; Weigert, Andreas

    2016-02-15

    Plasmacytoid dendritic cells (pDCs) produce large amounts of type I IFN in response to TLR7/9 ligands. This conveys antiviral effects, activates other immune cells (NK cells, conventional DCs, B, and T cells), and causes the induction and expansion of a strong inflammatory response. pDCs are key players in various type I IFN-driven autoimmune diseases such as systemic lupus erythematosus or psoriasis, but pDCs are also involved in (anti-)tumor immunity. The sphingolipid sphingosine-1-phosphate (S1P) signals through five G-protein-coupled receptors (S1PR1-5) to regulate, among other activities, immune cell migration and activation. The present study shows that S1P stimulation of human, primary pDCs substantially decreases IFN-α production after TLR7/9 activation with different types of CpG oligodeoxynucleotides or tick-borne encephalitis vaccine, which occurred in an S1PR4-dependent manner. Mechanistically, S1PR4 activation preserves the surface expression of the human pDC-specific inhibitory receptor Ig-like transcript 7. We provide novel information that Ig-like transcript 7 is rapidly internalized upon receptor-mediated endocytosis of TLR7/9 ligands to allow high IFN-α production. This is antagonized by S1PR4 signaling, thus decreasing TLR-induced IFN-α secretion. At a functional level, attenuated IFN-α production failed to alter Ag-driven T cell proliferation in pDC-dependent T cell activation assays, but shifted cytokine production of T cells from a Th1 (IFN-γ) to a regulatory (IL-10) profile. In conclusion, S1PR4 agonists block human pDC activation and may therefore be a promising tool to restrict pathogenic IFN-α production. PMID:26783340

  5. Defining the Roles of IFN-γ and IL-17A in Inflammation and Protection against Helicobacter pylori Infection

    PubMed Central

    Sjökvist Ottsjö, Louise; Flach, Carl-Fredrik; Nilsson, Staffan; de Waal Malefyt, Rene; Walduck, Anna K.; Raghavan, Sukanya

    2015-01-01

    CD4+ T cells have been shown to be essential for vaccine-induced protection against Helicobacter pylori infection. However, the effector mechanisms leading to reductions in the gastric bacterial loads of vaccinated mice remain unclear. We have investigated the function of IFN-γ and IL-17A for vaccine-induced protection and inflammation (gastritis) using IFN-γ-gene-knockout (IFN-γ-/-) mice, after sublingual or intragastric immunization with H. pylori lysate antigens and cholera toxin. Bacteria were enumerated in the stomachs of mice and related to the gastritis score and cellular immune responses. We report that sublingually and intragastrically immunized IFN-γ-/- mice had significantly reduced bacterial loads similar to immunized wild-type mice compared to respective unimmunized infection controls. The reduction in bacterial loads in sublingually and intragastrically immunized IFN-γ-/- mice was associated with significantly higher levels of IL-17A in stomach extracts and lower gastritis scores compared with immunized wild-type mice. To study the role of IL-17A for vaccine-induced protection in sublingually immunized IFN-γ-/- mice, IL-17A was neutralized in vivo at the time of infection. Remarkably, the neutralization of IL-17A in sublingually immunized IFN-γ-/- mice completely abolished protection against H. pylori infection and the mild gastritis. In summary, our results suggest that IFN-γ responses in the stomach of sublingually immunized mice promote vaccine-induced gastritis, after infection with H. pylori but that IL-17A primarily functions to reduce the bacterial load. PMID:26168305

  6. Adenovirus-specific T-cell Subsets in Human Peripheral Blood and After IFN-γ Immunomagnetic Selection.

    PubMed

    Qian, Chongsheng; Wang, Yingying; Cai, Huili; Laroye, Caroline; De Carvalho Bittencourt, Marcelo; Clement, Laurence; Stoltz, Jean-François; Decot, Véronique; Reppel, Loïc; Bensoussan, Danièle

    2016-01-01

    Adoptive antiviral cellular immunotherapy by infusion of virus-specific T cells (VSTs) is becoming an alternative treatment for viral infection after hematopoietic stem cell transplantation. The T memory stem cell (TSCM) subset was recently described as exhibiting self-renewal and multipotency properties which are required for sustained efficacy in vivo. We wondered if such a crucial subset for immunotherapy was present in VSTs. We identified, by flow cytometry, TSCM in adenovirus (ADV)-specific interferon (IFN)-γ+ T cells before and after IFN-γ-based immunomagnetic selection, and analyzed the distribution of the main T-cell subsets in VSTs: naive T cells (TN), TSCM, T central memory cells (TCM), T effector memory cell (TEM), and effector T cells (TEFF). In this study all of the different T-cell subsets were observed in the blood sample from healthy donor ADV-VSTs, both before and after IFN-γ-based immunomagnetic selection. As the IFN-γ-based immunomagnetic selection system sorts mainly the most differentiated T-cell subsets, we observed that TEM was always the major T-cell subset of ADV-specific T cells after immunomagnetic isolation and especially after expansion in vitro. Comparing T-cell subpopulation profiles before and after in vitro expansion, we observed that in vitro cell culture with interleukin-2 resulted in a significant expansion of TN-like, TCM, TEM, and TEFF subsets in CD4IFN-γ T cells and of TCM and TEM subsets only in CD8IFN-γ T cells. We demonstrated the presence of all T-cell subsets in IFN-γ VSTs including the TSCM subpopulation, although this was weakly selected by the IFN-γ-based immunomagnetic selection system. PMID:26641259

  7. Ligand-induced IFN gamma receptor tyrosine phosphorylation couples the receptor to its signal transduction system (p91).

    PubMed Central

    Greenlund, A C; Farrar, M A; Viviano, B L; Schreiber, R D

    1994-01-01

    Herein we report that interferon-gamma (IFN gamma) induces the rapid and reversible tyrosine phosphorylation of the IFN gamma receptor. Using a panel of receptor intracellular domain mutants, we show that a membrane-proximal LPKS sequence (residues 266-269) is required for ligand-induced tyrosine kinase activation and/or kinase-receptor association and biological responsiveness, and a functionally critical membrane-distal tyrosine residue (Y440) is a target of the activated enzyme. The biological significance of Y440 phosphorylation was demonstrated by showing that a receptor-derived nonapeptide corresponding to receptor residues 436-444 and containing phosphorylated Y440 bound specifically to p91, blocked p91 phosphorylation and inhibited the generation of an active p91-containing transcription factor complex. In contrast, nonphosphorylated wild-type, phosphorylated mutant, or phosphorylated irrelevant peptides did not. Moreover, the phosphorylated Y440-containing peptide did not interact with a related but distinct latent transcription factor (p113) which is activatible by IFN alpha but not IFN gamma. These results thus document the specific and inducible association of p91 with the phosphorylated IFN gamma receptor and thereby elucidate the mechanism by which ligand couples the IFN gamma receptor to its signal transduction system. Images PMID:8156998

  8. Successful Treatment of Human Visceral Leishmaniasis Restores Antigen-Specific IFN-γ, but not IL-10 Production

    PubMed Central

    Adem, Emebet; Tajebe, Fitsumbirhan; Getahun, Mulusew; Kiflie, Amare; Diro, Ermias; Hailu, Asrat; Shkedy, Ziv; Mengesha, Bewketu; Mulaw, Tadele; Atnafu, Saba; Deressa, Tekalign; Mathewos, Biniam; Abate, Ebba; Modolell, Manuel; Munder, Markus; Müller, Ingrid; Takele, Yegnasew; Kropf, Pascale

    2016-01-01

    One of the key immunological characteristics of active visceral leishmaniasis (VL) is a profound immunosuppression and impaired production of Interferon-γ (IFN-γ). However, recent studies from Bihar in India showed using a whole blood assay, that whole blood cells have maintained the capacity to produce IFN-γ. Here we tested the hypothesis that a population of low-density granulocytes (LDG) might contribute to T cell responses hyporesponsiveness via the release of arginase. Our results show that this population is affected by the anticoagulant used to collect blood: the frequency of LDGs is significantly lower when the blood is collected with heparin as compared to EDTA; however, the anticoagulant does not impact on the levels of arginase released. Next, we assessed the capacity of whole blood cells from patients with active VL to produce IFN-γ and IL-10 in response to antigen-specific and polyclonal activation. Our results show that whole blood cells produce low or levels below detection limit of IFN-γ and IL-10, however, after successful treatment of VL patients, these cells gradually regain their capacity to produce IFN-γ, but not IL-10, in response to activation. These results suggest that in contrast to VL patients from Bihar, India, whole blood cells from VL patients from Gondar, Ethiopia, have lost their ability to produce IFN-γ during active VL and that active disease is not associated with sustained levels of IL-10 production following stimulation. PMID:26962865

  9. Successful Treatment of Human Visceral Leishmaniasis Restores Antigen-Specific IFN-γ, but not IL-10 Production.

    PubMed

    Adem, Emebet; Tajebe, Fitsumbirhan; Getahun, Mulusew; Kiflie, Amare; Diro, Ermias; Hailu, Asrat; Shkedy, Ziv; Mengesha, Bewketu; Mulaw, Tadele; Atnafu, Saba; Deressa, Tekalign; Mathewos, Biniam; Abate, Ebba; Modolell, Manuel; Munder, Markus; Müller, Ingrid; Takele, Yegnasew; Kropf, Pascale

    2016-03-01

    One of the key immunological characteristics of active visceral leishmaniasis (VL) is a profound immunosuppression and impaired production of Interferon-γ (IFN-γ). However, recent studies from Bihar in India showed using a whole blood assay, that whole blood cells have maintained the capacity to produce IFN-γ. Here we tested the hypothesis that a population of low-density granulocytes (LDG) might contribute to T cell responses hyporesponsiveness via the release of arginase. Our results show that this population is affected by the anticoagulant used to collect blood: the frequency of LDGs is significantly lower when the blood is collected with heparin as compared to EDTA; however, the anticoagulant does not impact on the levels of arginase released. Next, we assessed the capacity of whole blood cells from patients with active VL to produce IFN-γ and IL-10 in response to antigen-specific and polyclonal activation. Our results show that whole blood cells produce low or levels below detection limit of IFN-γ and IL-10, however, after successful treatment of VL patients, these cells gradually regain their capacity to produce IFN-γ, but not IL-10, in response to activation. These results suggest that in contrast to VL patients from Bihar, India, whole blood cells from VL patients from Gondar, Ethiopia, have lost their ability to produce IFN-γ during active VL and that active disease is not associated with sustained levels of IL-10 production following stimulation. PMID:26962865

  10. IFN-γ Prevents Adenosine Receptor (A2bR) Upregulation To Sustain the Macrophage Activation Response.

    PubMed

    Cohen, Heather B; Ward, Amanda; Hamidzadeh, Kajal; Ravid, Katya; Mosser, David M

    2015-10-15

    The priming of macrophages with IFN-γ prior to TLR stimulation results in enhanced and prolonged inflammatory cytokine production. In this study, we demonstrate that, following TLR stimulation, macrophages upregulate the adenosine 2b receptor (A2bR) to enhance their sensitivity to immunosuppressive extracellular adenosine. This upregulation of A2bR leads to the induction of macrophages with an immunoregulatory phenotype and the downregulation of inflammation. IFN-γ priming of macrophages selectively prevents the induction of the A2bR in macrophages to mitigate sensitivity to adenosine and to prevent this regulatory transition. IFN-γ-mediated A2bR blockade leads to a prolonged production of TNF-α and IL-12 in response to TLR ligation. The pharmacologic inhibition or the genetic deletion of the A2bR results in a hyperinflammatory response to TLR ligation, similar to IFN-γ treatment of macrophages. Conversely, the overexpression of A2bR on macrophages blunts the IFN-γ effects and promotes the development of immunoregulatory macrophages. Thus, we propose a novel mechanism whereby IFN-γ contributes to host defense by desensitizing macrophages to the immunoregulatory effects of adenosine. This mechanism overcomes the transient nature of TLR activation, and prolongs the antimicrobial state of the classically activated macrophage. This study may offer promising new targets to improve the clinical outcome of inflammatory diseases in which macrophage activation is dysregulated. PMID:26355158

  11. Mycobacterium simiae infection in two unrelated patients with different forms of inherited IFN-γR2 deficiency

    PubMed Central

    Martínez-Barricarte, Rubén; Megged, Orli; Stepensky, Polina; Casimir, Pierre; Moncada-Velez, Marcela; Averbuch, Diana; Assous, Marc Victor; Abuzaitoun, Omar; Kong, Xiao-Fei; Pedergnana, Vincent; Deswarte, Caroline; Migaud, Mélanie; Rose-John, Stefan; Itan, Yuval; Boisson, Bertrand; Belkadi, Aziz; Conti, Francesca; Abel, Laurent; Vogt, Guillaume; Boisson-Dupuis, Stephanie; Casanova, Jean-Laurent; Bustamante, Jacinta

    2014-01-01

    Interferon-γ receptor 2 (IFN-γR2) deficiency is a rare primary immunodeficiency characterized by predisposition to infections with weakly virulent mycobacteria, such as environmental mycobacteria and BCG vaccines. We describe here two children with IFN-γR2 deficiency, from unrelated, consanguineous kindreds of Arab and Israeli descent. The first patient was a boy who died at the age of 4.5 years, from recurrent, disseminated disease caused by Mycobacterium simiae. His IFN-γR2 defect was autosomal recessive and complete. The second patient was a girl with multiple disseminated mycobacterial infections, including infection with M. simiae. She died at the age of five years, a short time after the transplantation of umbilical cord blood cells from an unrelated donor. Her IFN-γR2 defect was autosomal recessive and partial. Autosomal recessive IFN-γR2 deficiency is life-threatening, even in its partial form, and genetic diagnosis and familial counseling are therefore particularly important for this condition. These two cases are the first of IFN-γR2 deficiency associated with M simiae infection to be described. PMID:25135595

  12. Mycobacterium simiae infection in two unrelated patients with different forms of inherited IFN-γR2 deficiency.

    PubMed

    Martínez-Barricarte, Rubén; Megged, Orli; Stepensky, Polina; Casimir, Pierre; Moncada-Velez, Marcela; Averbuch, Diana; Assous, Marc Victor; Abuzaitoun, Omar; Kong, Xiao-Fei; Pedergnana, Vincent; Deswarte, Caroline; Migaud, Mélanie; Rose-John, Stefan; Itan, Yuval; Boisson, Bertrand; Belkadi, Aziz; Conti, Francesca; Abel, Laurent; Vogt, Guillaume; Boisson-Dupuis, Stephanie; Casanova, Jean-Laurent; Bustamante, Jacinta

    2014-11-01

    Interferon-γ receptor 2 (IFN-γR2) deficiency is a rare primary immunodeficiency characterized by predisposition to infections with weakly virulent mycobacteria, such as environmental mycobacteria and BCG vaccines. We describe here two children with IFN-γR2 deficiency, from unrelated, consanguineous kindreds of Arab and Israeli descent. The first patient was a boy who died at the age of 4.5 years, from recurrent, disseminated disease caused by Mycobacterium simiae. His IFN-γR2 defect was autosomal recessive and complete. The second patient was a girl with multiple disseminated mycobacterial infections, including infection with M. simiae. She died at the age of 5 years, a short time after the transplantation of umbilical cord blood cells from an unrelated donor. Her IFN-γR2 defect was autosomal recessive and partial. Autosomal recessive IFN-γR2 deficiency is life-threatening, even in its partial form, and genetic diagnosis and familial counseling are therefore particularly important for this condition. These two cases are the first of IFN-γR2 deficiency associated with M. simiae infection to be described. PMID:25135595

  13. IFN-τ Alleviates Lipopolysaccharide-Induced Inflammation by Suppressing NF-κB and MAPKs Pathway Activation in Mice.

    PubMed

    Wu, Haichong; Zhao, Gan; Jiang, Kangfeng; Chen, Xiuying; Rui, Guangze; Qiu, Changwei; Guo, Mengyao; Deng, Ganzhen

    2016-06-01

    IFN-τ, which is a type I interferon with low cytotoxicity, is defined as a pregnancy recognition signal in ruminants. Type I interferons have been used as anti-inflammatory agents, but their side effects limit their clinical application. The present study aimed to determine the anti-inflammatory effects of IFN-τ in a lipopolysaccharide-stimulated acute lung injury (ALI) model and in RAW264.7 cells and to confirm the mechanism of action involved. The methods used included histopathology, measuring the lung wet/dry ratio, determining the myeloperoxidase activity, ELISA, qPCR, and western blot. The results revealed that IFN-τ greatly ameliorated the infiltration of inflammatory cells and the expression of TNF-α, IL-1β, and IL-6. Further analysis revealed that IFN-τ down-regulated the expression of TLR-2 and TLR-4 mRNA and the activity of the NF-κB and MAPK pathways both in a lipopolysaccharide-induced ALI model and in RAW264.7 cells. The results demonstrated that IFN-τ suppressed the levels of pro-inflammatory cytokines by inhibiting the phosphorylation of the NF-κB and MAPK pathways. Thus, IFN-τ may be an optimal target for the treatment of inflammatory diseases. PMID:27052630

  14. Inhibition of hepatitis C virus replication by IFN-mediated ISGylation of HCV-NS5A.

    PubMed

    Kim, Min-Jung; Yoo, Joo-Yeon

    2010-10-01

    ISG15 is a ubiquitin-like molecule whose expression is induced by type I IFN (IFN-α/β) or in response to virus or bacterial infection. ISG15 or conjugation of ISG15 to target proteins was reported to play critical roles in the regulation of antiviral responses. IFN restricts replication of hepatitis C virus (HCV). However, molecular mechanism of IFN-α/β that inhibits HCV replication is not clear yet. In the current study, we demonstrated that replication of HCV was inhibited by overexpression of ISG15 and ISG15-conjugation enzymes in the HCV subgenomic replicon cells. Among various nonstructural proteins of HCV, NS5A was identified as the substrate for ISGylation. Furthermore, protein stability of NS5A was decreased by overexpression of ISG15 or ISG15-conjugating enzymes. The inhibitory effect of ISG15 or ISGylation on NS5A was efficiently blocked by substitution of lysine at 379 residue to arginine within the C-terminal region, suggesting that ISGylation directly controls protein stability of NS5A. Finally, the inhibitory effect of IFN-α/β on HCV replication was further enhanced by ISGylation, suggesting ISG15 as a therapeutic tool for combined therapy with IFN against HCV. PMID:20810994

  15. Therapeutic Strategies for SLE Involving Cytokines: Mechanism-Oriented Therapies Especially IFN-γ Targeting Gene Therapy

    PubMed Central

    Hayashi, Toshiharu

    2010-01-01

    Systemic lupus erythematosus (SLE: lupus) is a chronic complicated autoimmune disease and pathogenesis is still unclear. However, key cytokines have been recognized. Interferon (IFN)-γ and also IFNα/β are of particular importance. Depending on the concept that lupus is a helper T(Th)1 disease and that dendritic cells (DCs) determine the direction of lupus, balance shift of Th1/Th2 and immunogenic/tolerogenic DCs is reviewed for therapy. (IFN)-γ- and IFN-α/β-targeted (gene) therapies are introduced. These consist of Th1/Th2 balance shift and elimination of IFN-γ and IFN-γ-related cytokines such as (interleukin)IL-12 and IL-18. Other approaches include suppression of immunocompetent cells, normalization of abnormal T-cell function, costimulation blockade, B lymphocyte stimulator (Blys) blockade, and suppression of nephritic kidney inflammation. Moreover, balance shift of IFN-α/β and tumor necrosis factor (TNF)-α together with regulatory T(Treg) cells are briefely introduced. Clinical application will be discussed. PMID:20827419

  16. Modulation of the Fas signaling pathway by IFN-gamma in therapy of colon cancer: phase I trial and correlative studies of IFN-gamma, 5-fluorouracil, and leucovorin.

    PubMed

    Schwartzberg, Lee S; Petak, Istvan; Stewart, Clinton; Turner, P Kellie; Ashley, Jeri; Tillman, David M; Douglas, Leslie; Tan, Ming; Billups, Catherine; Mihalik, Rudolf; Weir, Alva; Tauer, Kurt; Shope, Steve; Houghton, Janet A

    2002-08-01

    Potentiation of 5-fluorouracil/leucovorin (FUra/LV) cytotoxicity by IFN-gamma in colon carcinoma cells is dependent on FUra-induced DNA damage, the Fas death receptor, and independent of p53 and RNA-mediated FUra toxicity, which occurs in normal gastrointestinal tissues. This provides a rationale for enhancing the selective action of FUra/LV by IFN-gamma in the treatment of colorectal carcinoma. Based on results from our preclinical studies we designed a Phase I trial combining FUra (370 mg/m2) and LV (200 mg/m2), i.v. bolus daily x 5 days, with escalating doses of IFN-gamma (10-100 micro g/m2) s.c. on days 1, 3, and 5, every 28 days. Twenty-five patients with carcinomas were enrolled; 6 patients received IFN-gamma on days 1 and 3 only. The dose-limiting toxicity, stomatitis, occurred most frequently at 100 micro g/m2 IFN-gamma. Minor response or SD was observed in 2 of 9 patients and in 4 of 12 patients at dose levels of < or =50 micro g/m2 and > or =75 micro g/m2 IFN-gamma, respectively. Three evaluable chemonaive patients demonstrated partial response (2) or complete response (1). Serial plasma samples revealed peak FUra concentrations of >100 micro M; at 100 micro g/m2 IFN-gamma plasma concentrations >5 units/ml persisted for 6.5 h and >1 unit/ml for 28.5 h. The pharmacokinetic parameters of IFN-gamma correlated with a 2-3-fold up-regulation of Fas expression at 24 h in CD15+ cells in peripheral blood samples. Furthermore, clinically relevant IFN-gamma concentrations up-regulated Fas expression and sensitized HT29 colon carcinoma cells in vitro to FUra/LV cytotoxicity. On the basis of the modulation of Fas signaling, FUra/LV combined with IFN-gamma has shown activity in a Phase I trial in colorectal carcinoma and warrants additional evaluation in Phase II. PMID:12171874

  17. T-2 toxin impairment of enteric reovirus clearance in the mouse associated with suppressed immunoglobulin and IFN-{gamma} responses

    SciTech Connect

    Li Maoxiang; Cuff, Christopher F.; Pestka, James J. . E-mail: pestka@msu.edu

    2006-08-01

    Trichothecenes are exquisitely toxic to the gastrointestinal (GI) tract and leukocytes and thus are likely to impair gut immunity. The purpose of this research was to test the hypothesis that the Type A trichothecene T-2 toxin interferes with the gut mucosal immune response to enteric reovirus infection. Mice were exposed i.p. first to 1.75 mg/kg bw T-2 and then 2 h later with 3 x 10{sup 7} plaque-forming units of reovirus serotype 1, strain Lang (T1/L). As compared to vehicle-treated control, T-2-treated mice had dramatically elevated intestinal plaque-forming viral titers after 5 days and failed to completely clear the virus from intestine by 10 days. Levels of reovirus {lambda}2 core spike (L2 gene) RNA in feces in T-2-treated mice were significantly higher at 1, 3, 5, and 7 days than controls. T-2 potentiated L2 mRNA expression in a dose-dependent manner with as little as 50 {mu}g/kg of the toxin having a potentiative effect. T-2 exposure transiently suppressed induction of reovirus-specific IgA in feces (6 and 8 days) as well as specific IgA and IgG{sub 2a} in serum (5 days). This suppression corresponded to decreased secretion of reovirus-specific IgA and IgG{sub 2a} in Peyer's patch (PP) and lamina propria fragment cultures prepared 5 days after infection. T-2 suppressed IFN-{gamma} responses in PP to reovirus at 3 and 7 days as compared to infected controls whereas IL-2 mRNA concentrations were unaffected. PP IL-6 mRNA levels were increased 2-fold 2 h after T-2 treatment, but no differences between infected T-2-exposed and infected vehicle-treated mice were detectable over the next 7 days. Overall, the results suggest that T-2 toxin increased both the extent of GI tract reovirus infection and fecal shedding which corresponded to both suppressed immunoglobulin and IFN-{gamma} responses.

  18. Role of TLR2-dependent IL-10 production in the inhibition of the initial IFN-γ T cell response to Porphyromonas gingivalis.

    PubMed

    Gaddis, Dalia E; Maynard, Craig L; Weaver, Casey T; Michalek, Suzanne M; Katz, Jannet

    2013-01-01

    P.g., a Gram-negative bacterium, is one of the main etiological agents of the chronic inflammatory disease, periodontitis. Disease progression is thought to occur as a result of an inadequate immune response, which although happens locally, can also occur distally as a result of the dissemination of P.g. into the circulation. As IL-10 and TLR2 are pivotal molecules in the immune response that P.g. elicits, we hypothesized that TLR2-mediated IL-10 production, following the initial systemic exposure to P.g., inhibits the IFN-γ T cell response. To address this hypothesis, mice were primed with P.g., and the types of cells producing IL-10 and the capacity of T cells to produce IFN-γ following blocking or neutralization of IL-10 were assessed. Our results showed that upon initial encounter with P.g., splenic T cells and CD11b(+) cells produce IL-10, which when neutralized, resulted in a substantial increase in IFN-γ production by T cells. Furthermore, IL-10 production was dependent on TLR2/1 signaling, partly in response to the major surface protein, FimA of P.g. In addition, P.g. stimulation resulted in the up-regulation of PD-1 and its ligand PD-L1 on CD4 T cells and CD11b(+) cells, respectively. Up-regulation of PD-1 was partially dependent on IL-10 but independent of TLR2 or FimA. These results highlight the role of IL-10 in inhibiting T cell responses to the initial systemic P.g. exposure and suggest multiple inhibitory mechanisms potentially used by P.g. to evade the host's immune response, thus allowing its persistence in the host. PMID:23077245

  19. NKG2D⁺ IFN-γ⁺ CD8⁺ T cells are responsible for palladium allergy.

    PubMed

    Kawano, Mitsuko; Nakayama, Masafumi; Aoshima, Yusuke; Nakamura, Kyohei; Ono, Mizuho; Nishiya, Tadashi; Nakamura, Syou; Takeda, Yuri; Dobashi, Akira; Takahashi, Akiko; Endo, Misato; Ito, Akiyo; Ueda, Kyosuke; Sato, Naoki; Higuchi, Shigehito; Kondo, Takeru; Hashimoto, Suguru; Watanabe, Masamichi; Watanabe, Makoto; Takahashi, Tetsu; Sasaki, Keiichi; Nakamura, Masanori; Sasazuki, Takehiko; Narushima, Takayuki; Suzuki, Ryuji; Ogasawara, Kouetsu

    2014-01-01

    Nickel, cobalt, and chromium are well known to be causal agents of allergic contact dermatitis. Palladium (Pd) can also cause allergic disease and exposure results from wide use of this metal in dental restorations and jewelry. Metal allergy is categorized as a delayed-type hypersensitivity, and metal-responsive T cell clones have been isolated from allergic patients. However, compared to nickel, little is known about the pathology of allergic disease mediated by Pd, and pathogenic T cells are poorly understood. To identify the pathogenic T cells that are responsible for onset of Pd allergy, we enriched metal-responsive lymphocytes by sequential adoptive transfer of involved lymph node cells. Here we show that sequential adoptive transfer gradually increased the incidence and the intensity of Pd allergy, and CD8⁺ T cells are responsible for the disease as CD8⁺ T cell-depleted mice and β2-microglobulin-deficient mice did not develop Pd allergy. In addition, we found that draining lymph node cells skewed toward CD8⁺ T cells in response to Pd challenge in 8th adoptive transferred recipient mice. The CD8⁺ T cells expressed NKG2D, a costimulatory molecule involved in the production of IFN-γ. NKG2D ligand was also induced in Pd-injected tissues. Furthermore, both NKG2D ligand-transgenic mice, where NKG2D is downmodulated, and IFN-γ-deficient mice showed impaired Pd allergy. Taken together, these results indicate that IFN-γ-producing NKG2D⁺ CD8⁺ T cells are responsible for Pd allergy and suggest that NKG2D is a potential therapeutic target for treatment of metal allergy. PMID:24533050

  20. Plasma Levels of IFN-γ, IL-4, IL-6 and IL-17 in HIV-Positive Patients With Oral Candidiasis

    PubMed Central

    Ayatollahi Mousavi, Seyyed Amin; Asadikaram, Gholamreza; Nakhaee, Nouzar; Izadi, Alireza

    2016-01-01

    Background: Cell-mediated immunity (CMI) by CD4 + Th (T helper)-type cells is the predominant host defense mechanism against Oral Candidiasis (OC) in HIV-infected individuals. Weakened CMI and depletion of CD4 + T cells are the main factor contributing to the output of OC in HIV-positive individuals. The cytokines produced by Th1, Th2 and Th17 cells play a role in mediating an increased susceptibility to OC during HIV infection. Objectives: The present study investigated plasma concentration of IFN-γ, IL-4, IL-6 and IL-17 in HIV-1 patients suffering from OC. Patients and Methods: In total, 98 samples in four groups (HIV-positive and HIV-negative persons with and without OC) were obtained from the oral cavities and cultured on Sabouraud’s dextrose agar and CHROMagar. Also blood samples were obtained to assess plasma level of IFN-γ, IL-4, IL-6 and IL-17 using ELISA technique. Results: There was a statistically significant difference in the plasma concentration of IFN-γ, IL-6 and IL-17 but not about IL-4. Our findings suggest a significant interaction between fungal infection and HIV on expression of assessed cytokines. Conclusions: Fungal infection and HIV alone and together could seriously alter immune system function as assessed by measuring the levels of the plasma cytokines. Therefore, these results provide important new information relative to the putative immune-based factors associated with resistance and/or susceptibility to OC in HIV-positive persons. PMID:27127595

  1. Suppression of Acute Graft-Versus-Host Response by TCDD Is Independent of the CTLA-4-IFN-γ-IDO pathway

    PubMed Central

    Kerkvliet, Nancy I.

    2013-01-01

    Activation of the aryl hydrocarbon receptor (AhR) by its prototypic ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), induces potent suppression of an acute graft-versus-host (GVH) response and prevents GVH disease (GVHD). Suppression is associated with development of a regulatory population of donor CD4+ CD25+T-cells that express high levels of cytotoxic T-lymphocyte antigen 4 (CTLA-4). However, a direct link between these AhR-induced Tregs (AhR-Tregs) and suppression of GVHD remains to be shown. CTLA-4 is a negative regulator of T-cell responses and is associated with the induction of tolerogenic dendritic cells (DCs) that produce indoleamine 2,3-dioxygenase (IDO). We hypothesized that AhR-Tregs mediate suppression via their enhanced expression of CTLA-4, which, in turn, induces IFN-γ and IDO in host DCs. Subsequent depletion of tryptophan by IDO leads to termination of the donor T-cell response prior to development of effector CTL. Here, we show that despite increased expression of Ifng, Irf3, Irf7, Ido1, and Ido2 in the lymph nodes of TCDD-treated host mice, inhibition of IDO enzyme activity by 1-methyl-tryptophan was unable to relieve TCDD-mediated suppression of the GVH response. Furthermore, treatment with an anti-CTLA-4 antibody that blocks CTLA-4 signaling was also unable to alleviate TCDD-mediated suppression. Alternatively, we investigated the possibility that donor-derived AhR-Tregs produce IFN-γ to suppress effector CTL development. However, suppression of GVHD by TCDD was not affected by the use of Ifng-deficient donor cells. Together, these results indicate that neither overexpression of CTLA-4 nor production of IFN-γ by AhR-Tregs plays a major role in the manifestation of their immunosuppressive function in vivo. PMID:23798565

  2. Effect of a four-week exercise program on the secretion of IFN-γ, TNF-α, IL-2 and IL-6 cytokines in elite Taekwondo athletes

    PubMed Central

    Kaya, Oktay

    2016-01-01

    The aim of the present study was to examine how a 4-week exercise program affects the serum levels of certain cytokines in Taekwondo athletes. The study involved 10 elite male Taekwondo athletes (mean age, 20.67±0.24 years; mean weight, 65.45±1.69 kg) who were studying at the Physical Education and Sports High School of Selçuk University (Konya, Turkey) in June 2014. The subjects were involved in a Taekwondo exercise program on every weekday for 4 weeks. The subjects were also engaged in an exercise to exhaustion session twice; once before starting the 4-week exercise program and once upon completion of the program. Blood samples were collected from the subjects in four rounds: During rest, upon fatigue, and before and after the 4-week exercise program. These samples were analyzed to establish the serum levels of interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), interleukin (IL)-2 and IL-6 using enzyme-linked immunosorbent assay test kits. Pre- and post-exercise program, the IFN-γ and TNF-α levels did not show any significant difference. When compared with the pre-exercise levels, serum IL-2 levels of the subjects were found to be elevated after the 4-week exercise program. The highest serum IL-6 values were established after the subjects were exercised to fatigue before the exercise program was initiated (P<0.05). The 4-week exercise program resulted in a decrease in IL-6 levels (P<0.05). The findings of the study indicate that a 4-week exercise program did not result in significant changes in IFN-γ and TNF-α levels, but led to an increase in IL-2 levels. The notable finding of the present study is that a 4-week exercise program reduces cellular immune functions and, thus, the levels of IL-6, which negatively influences performance. PMID:27588179

  3. IL-2, IL-5, TNF-α and IFN-γ mRNA expression in epidermal keratinocytes of systemic lupus erythematosus skin lesions

    PubMed Central

    Carneiro, José Ronaldo M; Fuzii, Hellen T; Kayser, Cristiane; Alberto, Fernando L; Soares, Fernando A; Sato, Emília I; Andrade, Luís Eduardo C

    2011-01-01

    OBJECTIVE: To analyze cytokine gene expression in keratinocytes from patients with systemic lupus erythematosus (SLE). INTRODUCTION: Keratinocytes represent 95% of epidermal cells and can secrete several cytokines. METHODS: Keratinocytes were obtained by laser microdissection from 21 patients with SLE (10 discoid and 11 acute lesions) at involved and uninvolved sites. All patients were receiving a low/moderate prednisone dose and 18 were receiving chloroquine diphosphate. IL-2, IL-5, TNF-α and IFN-γ gene expression was evaluated by real-time PCR and expressed as the ratio (R) to a pool of skin samples from 12 healthy volunteers. RESULTS: Heterogeneity in cytokine gene expression was found among patients with SLE. Eighteen of 38 valid SLE samples (47%) presented overexpression (R>1) of at least one cytokine. Lesional skin samples tended to show higher cytokine expression than samples from uninvolved skin (p = 0.06). IL-5 and IFN-γ were the most commonly overexpressed cytokines. Samples with cytokine overexpression corresponded to more extensive and severe lesions. Prednisone dose did not differ between samples without cytokine overexpression (15.71±3.45 mg/day) and those with overexpressed cytokines (12.68±5.41 mg/day) (p = 0.216). Samples from all patients not receiving diphosphate chloroquine had at least one overexpressed cytokine. CONCLUSIONS: The heterogeneous keratinocyte cytokine gene expression reflects the complex immunological and inflammatory background in SLE. Patients with severe/extensive skin lesions showed a higher frequency of cytokine gene overexpression. Increased IFN-γ and IL-5 expression suggests that Th1 and Th2 cells are involved in SLE skin inflammation. The possibility that prednisone and antimalarial drugs may have contributed to low cytokine gene expression in some samples cannot be ruled out. PMID:21437440

  4. Identification of alpha interferon-induced envelope mutations of hepatitis C virus in vitro associated with increased viral fitness and interferon resistance.

    PubMed

    Serre, Stéphanie B N; Krarup, Henrik B; Bukh, Jens; Gottwein, Judith M

    2013-12-01

    Alpha interferon (IFN-α) is an essential component of innate antiviral immunity and of treatment regimens for chronic hepatitis C virus (HCV) infection. Resistance to IFN might be important for HCV persistence and failure of IFN-based therapies. Evidence for HCV genetic correlates of IFN resistance is limited. Experimental studies were hampered by lack of HCV culture systems. Using genotype (strain) 1a(H77) and 3a(S52) Core-NS2 JFH1-based recombinants, we aimed at identifying viral correlates of IFN-α resistance in vitro. Long-term culture with IFN-α2b in Huh7.5 cells resulted in viral spread with acquisition of putative escape mutations in HCV structural and nonstructural proteins. Reverse genetic studies showed that primarily amino acid changes I348T in 1a(H77) E1 and F345V/V414A in 3a(S52) E1/E2 increased viral fitness. Single-cycle assays revealed that I348T and F345V/V414A enhanced viral entry and release, respectively. In assays allowing viral spread, these mutations conferred a level of IFN-α resistance exceeding the observed fitness effect. The identified mutations acted in a subtype-specific manner but were not found in genotype 1a and 3a patients, who failed IFN-α therapy. Studies with HCV recombinants with different degrees of culture adaptation confirmed the correlation between viral fitness and IFN-α resistance. In conclusion, in vitro escape experiments led to identification of HCV envelope mutations resulting in increased viral fitness and conferring IFN-α resistance. While we established a close link between viral fitness and IFN-α resistance, identified mutations acted via different mechanisms and appeared to be relatively specific to the infecting virus, possibly explaining difficulties in identifying signature mutations for IFN resistance. PMID:24049176

  5. Characterization of Amphioxus IFN Regulatory Factor Family Reveals an Archaic Signaling Framework for Innate Immune Response.

    PubMed

    Yuan, Shaochun; Zheng, Tingting; Li, Peiyi; Yang, Rirong; Ruan, Jie; Huang, Shengfeng; Wu, Zhenxin; Xu, Anlong

    2015-12-15

    The IFN regulatory factor (IRF) family encodes transcription factors that play important roles in immune defense, stress response, reproduction, development, and carcinogenesis. Although the origin of the IRF family has been dated back to multicellular organisms, invertebrate IRFs differ from vertebrate IRFs in genomic structure and gene synteny, and little is known about their functions. Through comparison of multiple amphioxus genomes, in this study we suggested that amphioxus contains nine IRF members, whose orthologs are supposed to be shared among three amphioxus species. As the orthologs to the vertebrate IRF1 and IRF4 subgroups, Branchiostoma belcheri tsingtauense (bbt)IRF1 and bbtIRF8 bind the IFN-stimulated response element (ISRE) and were upregulated when amphioxus intestinal cells were stimulated with poly(I:C). As amphioxus-specific IRFs, both bbtIRF3 and bbtIRF7 bind ISRE. When activated, they can be phosphorylated by bbtTBK1 and then translocate into nucleus for target gene transcription. As transcriptional repressors, bbtIRF2 and bbtIRF4 can inhibit the transcriptional activities of bbtIRF1, 3, 7, and 8 by competing for the binding of ISRE. Interestingly, amphioxus IRF2, IRF8, and Rel were identified as target genes of bbtIRF1, bbtIRF7, and bbtIRF3, respectively, suggesting a dynamic feedback regulation among amphioxus IRF and NF-κB. Collectively, to our knowledge we present for the first time an archaic IRF signaling framework in a basal chordate, shedding new insights into the origin and evolution of vertebrate IFN-based antiviral networks. PMID:26573836

  6. Two cis-DNA elements involved in myeloid-cell-specific expression and gamma interferon (IFN-gamma) activation of the human high-affinity Fc gamma receptor gene: a novel IFN regulatory mechanism.

    PubMed Central

    Perez, C; Wietzerbin, J; Benech, P D

    1993-01-01

    The human high-affinity receptor for the constant region of immunoglobulin G (human Fc gamma R1) is encoded by two mRNAs induced selectively by gamma interferon (IFN-gamma) and expressed in cells of myeloid lineage. The cis-DNA element (GRR) previously found to confer IFN-gamma responsiveness to this gene acts as an inducible enhancer and is the target of an IFN-gamma-activated factor(s) (GIRE-BP) in cells of different origins. Although the GRR motif is not related to the DNA elements involved in the regulation of other IFN-stimulated genes, GIRE-BP binding depends on the IFN-gamma-dependent activation of the 91-kDa protein known to be one of the factors of a transcriptional complex activated by IFN-alpha. Deletions of the Fc gamma R1 promoter allowed us to identify a 25-bp element, downstream from the GRR motif, conferring cell-type-specific expression. This element, called MATE (myeloid activating transcription element), is the DNA target for constitutive factors forming two complexes, MATE-BP1 and MATE-BP2. In accordance with the functional analysis, MATE-BP binding activities were detected in extracts prepared from myeloid cell lines such as THP-1, HL-60, and U-937 but not in HeLa cell extracts. The MATE motif is present not only in the promoter of other Fc receptor genes but also in several promoters of genes whose expression is restricted to monocytic cells. Our results suggest that human Fc gamma R1 gene expression in myeloid cells is initiated by the interaction of IFN-gamma-activated factors with cell-type-specific factors through their binding to the GRR and MATE motifs. Images PMID:8455606

  7. IFN-gamma plays a detrimental role in murine defense against nasal colonization of Staphylococcus aureus.

    PubMed

    Satorres, Sara Elena; Alcaráz, Lucía Esther; Cargnelutti, Ethelina; Di Genaro, Maria Silvia

    2009-04-27

    The anterior nares are the major reservoir in humans of Staphylococcus aureus with the risk of developing endogenous infections or transmitting infections to susceptible persons. The mechanisms that mediate attachment of staphylococci to the nasal mucosa are little known. The purpose of the present work was to study some factors that could influence the nasal colonization in an animal model of mice. We investigated the possible role of IFN-gamma. We used S. aureus ATCC 35556 (SA113) slime-producing and ATCC 25923 non-slime-producing strains. Male 6-week-old BALB/c, C57BL/6 (wild-type, WT), and gene-deficient IL-12p40 (IL-12p40-/-) or IL-4 (IL-4-/-) mice on C57BL/6 background were infected with a dose of S. aureus of 10(6) CFU in 10mul of saline. The total number of S. aureus CFU per nose and lung, specific IgA response and IFN-gamma levels were evaluated. Significant higher CFU were recovery from the narines of C57BL/6 compared with BALB/c mice either after ATCC 35556 (p<0.0001) and ATCC 25923 (p<0.02) strain infection. Low IgA response correlated with high bacterial counting in the C57BL/6 nasal region. Moreover, C57BL/6 mice showed major colonization of slime-producing S. aureus ATCC 35556 than non-slime-producing ATCC 25923 S. aureus strain (p<0.02). IL-12p40-/-mice clarified the bacteria from their nose more efficiently that WT mice after slime-producing S. aureus (p<0.0001). Accordingly, significant lower level of IFN-gamma were detected in IL-12p40-/- compared with WT mice after infection with this strain (p<0.03). The results suggested the influence of the slime production in nasal colonization of S. aureus, and indicate at first time that IFN-gamma may play a detrimental role in this mucosal infection. These results could contribute to elucidate mucosal immune mechanisms involved in S. aureus colonization and then control infections in susceptible persons. PMID:19428568

  8. Combination of TLR1/2 and TLR3 ligands enhances CD4+ T cell longevity and antibody responses by modulating type I IFN production

    PubMed Central

    Lee, Bo Ryeong; Jeong, Soo Kyung; Ahn, Byung Cheol; Lee, Byeong-Jae; Shin, Sung Jae; Yum, Jung Sun; Ha, Sang-Jun

    2016-01-01

    Despite the possibility of combining Toll-like receptor (TLR) ligands as adjuvants to improve vaccine efficacy, it remains unclear which combinations of TLR ligands are effective or what their underlying mechanisms may be. Here, we investigated the mechanism of action of L-pampo, a proprietary adjuvant composed of TLR1/2 and TLR3 ligands. L-pampo dramatically increased humoral immune responses against the tested target antigens, which was correlated with an increase in follicular helper T cells and the maintenance of antigen-specific CD4+ T cells. During the initial priming phase, in contrast to the induction of type I interferon (IFN) and pro-inflammatory cytokines stimulated by polyI:C, L-pampo showed a greatly diminished induction of type I IFN, but not of other cytokines, and remarkably attenuated IRF3 signaling, which appeared to be critical to L-pampo-mediated adjuvanticity. Collectively, our results demonstrate that the adjuvant L-pampo contributes to the promotion of antigen-specific antibodies and CD4+ T cell responses via a fine regulation of the TLR1/2 and TLR3 signaling pathways, which may be helpful in the design of improved vaccines. PMID:27580796

  9. Combination of TLR1/2 and TLR3 ligands enhances CD4(+) T cell longevity and antibody responses by modulating type I IFN production.

    PubMed

    Lee, Bo Ryeong; Jeong, Soo Kyung; Ahn, Byung Cheol; Lee, Byeong-Jae; Shin, Sung Jae; Yum, Jung Sun; Ha, Sang-Jun

    2016-01-01

    Despite the possibility of combining Toll-like receptor (TLR) ligands as adjuvants to improve vaccine efficacy, it remains unclear which combinations of TLR ligands are effective or what their underlying mechanisms may be. Here, we investigated the mechanism of action of L-pampo, a proprietary adjuvant composed of TLR1/2 and TLR3 ligands. L-pampo dramatically increased humoral immune responses against the tested target antigens, which was correlated with an increase in follicular helper T cells and the maintenance of antigen-specific CD4(+) T cells. During the initial priming phase, in contrast to the induction of type I interferon (IFN) and pro-inflammatory cytokines stimulated by polyI:C, L-pampo showed a greatly diminished induction of type I IFN, but not of other cytokines, and remarkably attenuated IRF3 signaling, which appeared to be critical to L-pampo-mediated adjuvanticity. Collectively, our results demonstrate that the adjuvant L-pampo contributes to the promotion of antigen-specific antibodies and CD4(+) T cell responses via a fine regulation of the TLR1/2 and TLR3 signaling pathways, which may be helpful in the design of improved vaccines. PMID:27580796

  10. T Cells Detect Intracellular DNA but Fail to Induce Type I IFN Responses: Implications for Restriction of HIV Replication

    PubMed Central

    Kofod-Olsen, Emil; Holm, Christian K.; Melchjorsen, Jesper; Jensen, David G.; Hansen, Anne Louise; Jørgensen, Louise B.; Ostergaard, Lars; Tolstrup, Martin; Larsen, Carsten S.; Paludan, Søren R.; Jakobsen, Martin R.; Mogensen, Trine H.

    2014-01-01

    HIV infects key cell types of the immune system, most notably macrophages and CD4+ T cells. Whereas macrophages represent an important viral reservoir, activated CD4+ T cells are the most permissive cell types supporting high levels of viral replication. In recent years, it has been appreciated that the innate immune system plays an important role in controlling HIV replication, e.g. via interferon (IFN)-inducible restriction factors. Moreover, innate immune responses are involved in driving chronic immune activation and the pathogenesis of progressive immunodeficiency. Several pattern recognition receptors detecting HIV have been reported, including Toll-like receptor 7 and Retinoic-inducible gene-I, which detects viral RNA. Here we report that human primary T cells fail to induce strong IFN responses, despite the fact that this cell type does express key molecules involved in DNA signaling pathways. We demonstrate that the DNA sensor IFI16 migrates to sites of foreign DNA localization in the cytoplasm and recruits the signaling molecules stimulator of IFN genes and Tank-binding kinase, but this does not result in expression of IFN and IFN-stimulated genes. Importantly, we show that cytosolic DNA fails to affect HIV replication. However, exogenous treatment of activated T cells with type I IFN has the capacity to induce expression of IFN-stimulated genes and suppress HIV replication. Our data suggest the existence of an impaired DNA signaling machinery in T cells, which may prevent this cell type from activating cell-autonomous anti-HIV responses. This phenomenon could contribute to the high permissiveness of CD4+ T cells for HIV-1. PMID:24404168

  11. Probing the Attenuation and Protective Efficacy of a Candidate Chikungunya Virus Vaccine in Mice with Compromised Interferon (IFN) Signaling

    PubMed Central

    Partidos, Charalambos D.; Weger, James; Brewoo, Joseph; Seymour, Robert; Borland, Erin M.; Ledermann, Jeremy P.; Powers, Ann M.; Weaver, Scott C.; Stinchcomb, Dan T.; Osorio, Jorge E.

    2011-01-01

    Chikungunya virus (CHIKV) is a mosquito-borne alphavirus that causes explosive outbreaks of febrile illness associated with rash, and painful arthralgia. The CHIK vaccine strain 181/clone25 (181/25) developed by the United States Army Medical Research Institute of Infectious Diseases (USAMRIID) was shown to be well-tolerated and highly immunogenic in phase I and II clinical trials although it induced transient arthralgia in some healthy adult volunteers. In an attempt to better understand the host factors that are involved in the attenuating phenotype of CHIK 181/25 vaccine virus we conducted studies in interferon (IFN)-compromised mice and also evaluated its immunogenic potential and protective capacity. Infection of AG129 mice (defective in IFN-α/β and IFN-γ receptor signaling) with CHIK 181/25 resulted in rapid mortality within 3-4 days. In contrast, all infected A129 mice (defective in IFN-α/β receptor signaling) survived with temporary morbidity characterized by ruffled appearance and body weight loss. A129 heterozygote mice that retain partial IFN-α/β receptor signaling activity remained healthy. Infection of A129 mice with CHIK 181/25 induced significant levels of IFN-γ and IL-12 while the inflammatory cytokines, TNFα and IL-6 remained low. A single administration of the CHIK 181/25 vaccine provided both short-term and long-term protection (38 days and 247 days post-prime, respectively) against challenge with wt CHIKV-La Reunion (CHIKV-LR). This protection was at least partially mediated by antibodies since passively transferred immune serum protected both A129 and AG129 mice from wt CHIKV-LR and 181/25 virus challenge. Overall, these data highlight the importance of IFNs in controlling CHIK 181/25 vaccine and demonstrate the ability of this vaccine to elicit neutralizing antibody responses that confer short-and long-term protection against wt CHIKV-LR challenge. PMID:21300099

  12. Mice with a selective impairment of IFN-γ signaling in macrophage lineage cells demonstrate the critical role of IFN-γ activated macrophages for the control of protozoan parasitic infections in vivo1, 2

    PubMed Central

    Lykens, Jennifer E.; Terrell, Catherine E.; Zoller, Erin E.; Divanovic, Senad; Trompette, Aurelien; Karp, Christopher L.; Aliberti, Julio; Flick, Matthew J.; Jordan, Michael B.

    2010-01-01

    IFN-γ has long been recognized as a cytokine with potent and varied effects in the immune response. While its effects on specific cell types have been well studied in vitro, its in vivo effects are less clearly understood because of its diverse actions on many different cell types. While control of multiple protozoan parasites is thought to depend critically on the direct action of IFN-γ on macrophages, this premise has never been directly proven in vivo. In order to more directly examine the effects of IFN-γ on cells of the macrophage lineage in vivo, we generated mice called the ‘Macrophages Insensitive to Interferon Gamma’ (MIIG) mice, which express a dominant negative mutant IFN-γ receptor in CD68+ cells: monocytes, macrophages, dendritic cells, and mast cells. Macrophage lineage cells and mast cells from these mice are unable to respond to IFN-γ while other cells are able to produce and respond to this cytokine normally. When challenged in vitro, macrophages from MIIG mice were unable produce NO or kill Trypanosoma cruzi or Leishmania major after priming with IFN-γ. Furthermore, MIIG mice demonstrated impaired parasite control and heightened mortality after T. cruzi, L. major, and Toxoplasma gondii infection, despite an appropriate IFN-γ response. In contrast, MIIG mice displayed normal control of lymphocytic choriomeningitis virus, despite persistent insensitivity of macrophages to IFN-γ. Thus, the MIIG mouse formally demonstrates for the first time in vivo, the specific importance of direct, IFN-γ mediated activation of macrophages for controlling infection with multiple protozoan parasites. “This is an author-produced version of a manuscript accepted for publication in The Journal of Immunology (The JI). The American Association of Immunologists, Inc. (AAI), publisher of The JI, holds the copyright to this manuscript. This version of the manuscript has not yet been copyedited or subjected to editorial proofreading by The JI; hence, it may

  13. In utero sensitization modulates IgG isotype, IFN-γ and IL-10 responses of neonates in bancroftian filariasis.

    PubMed

    Achary, K G; Mandal, N N; Mishra, S; Mishra, R; Sarangi, S S; Satapathy, A K; Kar, S K; Bal, M S

    2014-10-01

    In utero exposure has been considered as a risk factor for filarial infection. To evaluate the influence of maternal infection on filarial-specific IgG subclass response in neonates and their correlation with plasma levels IL-10 and interferon-γ, 145 pairs of mothers and their respective cord bloods were examined. Transplacental transfer of circulating filarial antigen (CFA) was observed in 34·8% cord bloods from CFA positive mothers. Filarial-specific IgG1, IgG2 and IgG4 responses of cord bloods were found to be positively correlated with CFA of mothers. In contrast, IgG3 responses negatively correlated with CFA of mothers. The % of similarity of recognition pattern in the cord blood with maternal blood was high for IgG3 response than IgG4 in all three groups. An increased levels of IL-10 and decreased levels of interferon gamma (IFN-γ) were observed in cord blood of infected mothers. Interferon gamma was positively correlated with IgG3 and negatively correlated with IgG4 level. On the other hand, IL-10 was positively correlated with IgG4 and CFA, indicating that cytokines may play a role in modulating the immune responses in cord bloods of sensitized foetus. The findings of the study reveal that in utero tolerance or sensitization may influence the filarial-specific immunity to infection in neonates. PMID:24902619

  14. Inhibition of IFN-γ-Induced Nitric Oxide Dependent Antimycobacterial Activity by miR-155 and C/EBPβ

    PubMed Central

    Qin, Yongwei; Wang, Qinglan; Zhou, Youlang; Duan, Yinong; Gao, Qian

    2016-01-01

    miR-155 (microRNA-155) is an important non-coding RNA in regulating host crucial biological regulators. However, its regulatory function in mycobacterium infection remains unclear. Our study demonstrates that miR-155 expression is significantly increased in macrophages after Mycobacterium marinum (M.m) infection. Transfection with anti-miR-155 enhances nitric oxide (NO) synthesis and decreases the mycobacterium burden, and vice versa, in interferon γ (IFN-γ) activated macrophages. More importantly, miR-155 can directly bind to the 3′UTR of CCAAT/enhancer binding protein β (C/EBPβ), a positive transcriptional regulator of nitric oxide synthase (NOS2), and regulate C/EBPβ expression negatively. Knockdown of C/EBPβ inhibit the production of nitric oxide synthase and promoted mycobacterium survival. Collectively, these data suggest that M.m-induced upregulation of miR-155 downregulated the expression of C/EBPβ, thus decreasing the production of NO and promoting mycobacterium survival, which may provide an insight into the function of miRNA in subverting the host innate immune response by using mycobacterium for its own profit. Understanding how miRNAs partly regulate microbicidal mechanisms may represent an attractive way to control tuberculosis infectious. PMID:27070591

  15. Three functional variants of IFN regulatory factor 5 (IRF5) define risk and protective haplotypes for human lupus

    PubMed Central

    Graham, Robert R.; Kyogoku, Chieko; Sigurdsson, Snaevar; Vlasova, Irina A.; Davies, Leela R. L.; Baechler, Emily C.; Plenge, Robert M.; Koeuth, Thearith; Ortmann, Ward A.; Hom, Geoffrey; Bauer, Jason W.; Gillett, Clarence; Burtt, Noel; Cunninghame Graham, Deborah S.; Onofrio, Robert; Petri, Michelle; Gunnarsson, Iva; Svenungsson, Elisabet; Rönnblom, Lars; Nordmark, Gunnel; Gregersen, Peter K.; Moser, Kathy; Gaffney, Patrick M.; Criswell, Lindsey A.; Vyse, Timothy J.; Syvänen, Ann-Christine; Bohjanen, Paul R.; Daly, Mark J.; Behrens, Timothy W.; Altshuler, David

    2007-01-01

    Systematic genome-wide studies to map genomic regions associated with human diseases are becoming more practical. Increasingly, efforts will be focused on the identification of the specific functional variants responsible for the disease. The challenges of identifying causal variants include the need for complete ascertainment of genetic variants and the need to consider the possibility of multiple causal alleles. We recently reported that risk of systemic lupus erythematosus (SLE) is strongly associated with a common SNP in IFN regulatory factor 5 (IRF5), and that this variant altered spicing in a way that might provide a functional explanation for the reproducible association to SLE risk. Here, by resequencing and genotyping in patients with SLE, we find evidence for three functional alleles of IRF5: the previously described exon 1B splice site variant, a 30-bp in-frame insertion/deletion variant of exon 6 that alters a proline-, glutamic acid-, serine- and threonine-rich domain region, and a variant in a conserved polyA+ signal sequence that alters the length of the 3′ UTR and stability of IRF5 mRNAs. Haplotypes of these three variants define at least three distinct levels of risk to SLE. Understanding how combinations of variants influence IRF5 function may offer etiological and therapeutic insights in SLE; more generally, IRF5 and SLE illustrates how multiple common variants of the same gene can together influence risk of common disease. PMID:17412832

  16. IRF-1 responsiveness to IFN-γ predicts different cancer immune phenotypes

    PubMed Central

    Murtas, D; Maric, D; De Giorgi, V; Reinboth, J; Worschech, A; Fetsch, P; Filie, A; Ascierto, M L; Bedognetti, D; Liu, Q; Uccellini, L; Chouchane, L; Wang, E; Marincola, F M; Tomei, S

    2013-01-01

    Background: Several lines of evidence suggest a dichotomy between immune active and quiescent cancers, with the former associated with a good prognostic phenotype and better responsiveness to immunotherapy. Central to such dichotomy is the master regulator of the acute inflammatory process interferon regulatory factor (IRF)-1. However, it remains unknown whether the responsiveness of IRF-1 to cytokines is able to differentiate cancer immune phenotypes. Methods: IRF-1 activation was measured in 15 melanoma cell lines at basal level and after treatment with IFN-γ, TNF-α and a combination of both. Microarray analysis was used to compare transcriptional patterns between cell lines characterised by high or low IRF-1 activation. Results: We observed a strong positive correlation between IRF-1 activation at basal level and after IFN-γ and TNF-α treatment. Microarray demonstrated that three cell lines with low and three with high IRF-1 inducible translocation scores differed in the expression of 597 transcripts. Functional interpretation analysis showed mTOR and Wnt/β-cathenin as the top downregulated pathways in the cell lines with low inducible IRF-1 activation, suggesting that a low IRF-1 inducibility recapitulates a cancer phenotype already described in literature characterised by poor prognosis. Conclusion: Our findings support the central role of IRF-1 in influencing different tumour phenotypes. PMID:23807161

  17. Children with recurrent otitis show defective IFN gamma-producing cells in adenoids.

    PubMed

    Avanzini, Antonietta M; Castellazzi, Anna Maria; Marconi, Massimo; Valsecchi, Chiara; Marseglia, Alessia; Ciprandi, Giorgio; De Silvestri, Annalisa; Marseglia, Gian Luigi

    2008-09-01

    Infectious diseases are frequently observed in children and their recurrence represents a demanding challenge for the paediatrician. It has been hypothesized that a defective immune response may occur in these patients. The aim of the present study was to evaluate whether children presenting with recurrent otitis have a defective interferon (IFN)gamma production by the lymphocytes of peripheral blood and of adenoid tissue, in comparison with children without recurrent otitis. Our study group was represented by 58 children undergoing adenoidectomy for adenoidal hypertrophy. They were subdivided into two groups according to the recurrence of otitis (>or=3 per year) or not (<3 per year). Intracellular cytokine profile of lymphocyte subsets in adenoids and peripheral blood was evaluated by flow cytometry analysis. Children with recurrent otitis showed a significantly lower percentage of CD8+-producing IFN gamma cells in adenoids than children with <3 otitis per year (p = 0.003). The reduced capability of the adenoid cells to produce INF-gamma may induce a high susceptibility to the recurrence of otitis in children. PMID:18266836

  18. The IFN-gamma +874T/A gene polymorphism is associated with retinochoroiditis toxoplasmosis susceptibility.

    PubMed

    Albuquerque, Maíra Cavalcanti de; Aleixo, Ana Luisa Quintella do Couto; Benchimol, Eliezer Israel; Leandro, Ana Cristina Câmara S; das Neves, Leandro Batista; Vicente, Regiane Trigueiro; Bonecini-Almeida, Maria da Glória; Amendoeira, Maria Regina Reis

    2009-05-01

    Toxoplasmosis is a worldwide zoonosis that generally produces an asymptomatic infection. In some cases, however, toxoplasmosis infection can lead to ocular damage. The immune system has a crucial role in both the course of the infection and in the evolution of toxoplasmosis disease. In particular, IFN-gamma plays an important role in resistance to toxoplasmosis. Polymorphisms in genes encoding cytokines have been shown to have an association with susceptibility to parasitic diseases. The aim of this work was to analyse the occurrence of polymorphisms in the gene encoding IFN-gamma (+874T/A) among Toxoplasma gondii seropositive individuals, including those with ocular lesions caused by the parasite, from a rural population of Santa Rita de Cássia, Barra Mansa, state of Rio de Janeiro, Brazil. Further, we verified which of these polymorphisms could be related to susceptibility to the development of ocular toxoplasmosis. This study included 34 individuals with ocular toxoplasmosis (ocular group) and 134 without ocular lesions (control group). The differences between A and T allele distributions were not statistically significant between the two groups. However, we observed that a higher frequency of individuals from the ocular group possessed the A/A genotype, when compared with the control group, suggesting that homozygocity for the A allele could enhance susceptibility to ocular toxoplasmosis in T. gondii infection. PMID:19547871

  19. Constitutive and IFN-gamma-induced nuclear import of STAT1 proceed through independent pathways.

    PubMed

    Meyer, Thomas; Begitt, Andreas; Lödige, Inga; van Rossum, Marleen; Vinkemeier, Uwe

    2002-02-01

    STAT1 functions as both a constitutive transcriptional regulator and, in response to cytokine stimulation of cells, as an inducible tyrosine-phosphorylated transcription factor. Here, we identify and characterize a non-transferable nuclear targeting sequence in the STAT1 DNA-binding domain. This conserved signal is critical for the interferon-gamma (IFN-gamma)-induced nuclear import of phosphorylated STAT1 dimers and requires adjacent positively charged and hydrophobic residues for functioning. Additionally, the constitutive nucleocytoplasmic shuttling of STAT1 in the absence of IFN-gamma stimulation is revealed. Nuclear import and export of unphosphorylated STAT1 are demonstrated to be sensitive towards wheat germ agglutinin and to occur independently of the import receptor p97. Loss-of-function mutations of the dimer-specific import signal block nuclear entry of tyrosine-phosphorylated STAT1, which in turn also prevents induction of cytokine-inducible target genes. Nevertheless, nuclear import of unphosphorylated STAT1 continues and the STAT1-dependent constitutive expression of caspases and the tumor necrosis factor-alpha-mediated induction of apoptosis proceed unaltered. Thus, tyrosine-phosphorylated and unphosphorylated STAT1 molecules shuttle via independent pathways to distinct sets of target genes. PMID:11823427

  20. Pro-lymphangiogenic properties of IFN-γ-activated human dendritic cells.

    PubMed

    Gagliostro, Vincenzo; Seeger, Pascal; Garrafa, Emirena; Salvi, Valentina; Bresciani, Roberto; Bosisio, Daniela; Sozzani, Silvano

    2016-05-01

    Dendritic cells (DCs) play a crucial role in the initiation of adaptive immune responses. In addition, through the release of pro- and anti-angiogenic mediators, DCs are key regulators of blood vessel remodeling, a process that characterizes inflammation. Less information is available on the role of DCs in lymphangiogenesis. This study reports that human DCs produce VEGF-C, a cytokine with potent pro-lymphangiogenic activity when stimulated with IFN-γ. DC-derived VEGF-C was biologically active, being able to promote tube-like structure formation in cultures of human lymphatic endothelial cells (LECs). DCs co-cultured with IL-15-activated NK cells produced high levels of VEGF-C, suggesting a role for NK-DC cross-talk in peripheral lymphoid and non-lymphoid tissues in inflammation-associated lymphangiogenesis. Induction of VEGF-C by IFN-γ was detected also in other myeloid cells, such as blood-purified CD1c(+) DCs, CD14(+) monocytes and in monocyte-derived macrophages. In all these cell types, VEGF-C was found associated with the cell membrane by low affinity, heparan sulphate-mediated, interactions. Therefore, human DCs should be considered as new players in inflammation-associated lymphangiogenesis. PMID:26987844

  1. Type I and III IFNs Produced by Plasmacytoid Dendritic Cells in Response to a Member of the Flaviviridae Suppress Cellular Immune Responses.

    PubMed

    Reid, Elizabeth; Juleff, Nicholas; Windsor, Miriam; Gubbins, Simon; Roberts, Lisa; Morgan, Sophie; Meyers, Gregor; Perez-Martin, Eva; Tchilian, Elma; Charleston, Bryan; Seago, Julian

    2016-05-15

    The pestivirus noncytopathic bovine viral diarrhea virus (BVDV) can suppress IFN production in the majority of cell types in vitro. However, IFN is detectable in serum during acute infection in vivo for ∼5-7 d, which correlates with a period of leucopoenia and immunosuppression. In this study, we demonstrate that a highly enriched population of bovine plasmacytoid dendritic cells (DCs) produced IFN in response to BVDV in vitro. We further show that the majority of the IFN produced in response to infection both in vitro and in vivo is type III IFN and acid labile. Further, we show IL-28B (IFN-λ3) mRNA is induced in this cell population in vitro. Supernatant from plasmacytoid DCs harvested postinfection with BVDV or recombinant bovine IFN-α or human IL-28B significantly reduced CD4(+) T cell proliferation induced by tubercle bacillus Ag 85-stimulated monocyte-derived DCs. Furthermore, these IFNs induced IFN-stimulated gene expression predominantly in monocyte-derived DCs. IFN-treated immature DCs derived from murine bone marrow also had a reduced capacity to stimulate T cell proliferative responses to tubercle bacillus Ag 85. Immature DCs derived from either source had a reduced capacity for Ag uptake following IFN treatment that is dose dependent. Immunosuppression is a feature of a number of pestivirus infections; our studies suggest type III IFN production plays a key role in the pathogenesis of this family of viruses. Overall, in a natural host, we have demonstrated a link between the induction of type I and III IFN after acute viral infection and transient immunosuppression. PMID:27053760

  2. Lack of essential role of NF-kappa B p50, RelA, and cRel subunits in virus-induced type 1 IFN expression.

    PubMed

    Wang, Xingyu; Hussain, Sofia; Wang, Emilie-Jeanne; Wang, Xiuyan; Li, Ming O; García-Sastre, Adolfo; Beg, Amer A

    2007-06-01

    Type 1 IFNs (IFN-alphabeta) play pivotal roles in the host antiviral response and in TLR-induced signaling. IFN regulatory factor (IRF) and NF-kappaB transcription factors are thought to be crucial for virus-induced mRNA expression of IFN-beta. Although recent studies have demonstrated essential roles for IRF3 and IRF7, the definitive role of NF-kappaB factors in IFN-beta (or IFN-alpha) expression remains unknown. Using mice deficient in distinct members of the NF-kappaB family, we investigated NF-kappaB function in regulating type 1 IFN expression in response to Sendai virus and Newcastle disease virus infection. Surprisingly, IFN-beta and IFN-alpha expression was strongly induced following virus infection of mouse embryonic fibroblasts (MEFs) from p50(-/-), RelA/p65(-/-), cRel(-/-), p50(-/-)cRel(-/-), and p50(-/-)RelA(-/-) mice. Compared with wild-type MEFs, only RelA(-/-) and p50(-/-)RelA(-/-) MEFs showed a modest reduction in IFN-beta expression. To overcome functional redundancy between different NF-kappaB subunits, we expressed a dominant-negative IkappaBalpha protein in p50(-/-)RelA(-/-) MEFs to inhibit activation of remaining NF-kappaB subunits. Although viral infection of these cells failed to induce detectable NF-kappaB activity, both Sendai virus and Newcastle disease virus infection led to robust IFN-beta expression. Virus infection of dendritic cells or TLR9-ligand CpG-D19 treatment of plasmacytoid dendritic cells from RelA(-/-) or p50(-/-)cRel(-/-) mice also induced robust type 1 IFN expression. Our findings therefore indicate that NF-kappaB subunits p50, RelA, and cRel play a relatively minor role in virus-induced type 1 IFN expression. PMID:17513724

  3. Type I IFN-Inducible Downregulation of MicroRNA-27a Feedback Inhibits Antiviral Innate Response by Upregulating Siglec1/TRIM27.

    PubMed

    Zheng, Qingliang; Hou, Jin; Zhou, Ye; Yang, Yingyun; Cao, Xuetao

    2016-02-01

    Upon recognition of viral components by pattern recognition receptors, including TLRs and retinoic acid-inducible gene I-like helicases, cells are activated to produce type I IFN, which plays key roles in host antiviral innate immune response. However, excessive IFN production may induce immune disorders, and the mechanisms responsible for the regulation of type I IFN production have attracted much attention. Furthermore, type I IFN activates the downstream IFN/JAK/STAT pathway to modulate expression of a set of genes against viral infection, but whether these genes can feedback regulate type I IFN production is poorly understood. In this study, by screening the microRNAs modulated by viral infection in macrophages, we identified that microRNA (miR)-27a was significantly downregulated via the IFN/JAK/STAT1/runt-related transcription factor 1 pathway. Inducible downregulation of miR-27a, in turn, negatively regulated vesicular stomatitis virus-triggered type I IFN production, thus promoting vesicular stomatitis virus replication in macrophages. Mechanistically, we found that miR-27a directly targeted sialic acid-binding Ig-like lectin (Siglec)1 and E3 ubiquitin ligase tripartite motif-containing protein 27 (TRIM27), both of which were previously verified as negative regulators of type I IFN production. Furthermore, we constructed "Sponge" transgenic mice against miR-27a expression and found that Siglec1 and TRIM27 expression were elevated whereas type I IFN production was inhibited and viral replication was aggregated in vivo. Therefore, type I IFN-induced downregulation of miR-27a can upregulate Siglec1 and TRIM27 expression, feedback inhibiting type I IFN production in antiviral innate response. Our study outlines a new negative way to feedback regulate type I IFN production. PMID:26700765

  4. Functional dichotomy of Vδ2 γδ T cells in chronic hepatitis C virus infections: role in cytotoxicity but not for IFN-γ production.

    PubMed

    Yin, Wenwei; Tong, Shiwen; Zhang, Qiongfang; Shao, Jianying; Liu, Qian; Peng, Hong; Hu, Huaidong; Peng, Mingli; Hu, Peng; Ren, Hong; Tian, Zhigang; Zhang, Dazhi

    2016-01-01

    Vδ2 γδ (Vδ2) T cells, a major human γδ T cell subset, exhibit broad anti-tumor and anti-infective activity; however, their precise role in chronic hepatitis C virus (HCV) infections remains unclear. In this study, we analyzed the phenotype and function of Vδ2 T cells in 43 HCV-infected patients compared to 39 healthy controls (HCs). Vδ2 T cells from HCV-infected patients were activated and differentiated into effector cells. Vδ2 T cells in patients expressed significantly higher levels of natural killer (NK) cell markers CD56 and CD16 than in HCs, acquiring cytotoxic NK-like phenotype. The Vδ2 T cell phenotype was associated with increased cytolytic effector molecules expression in HCV-infected patients with elevated serum ALT levels. Surprisingly, Vδ2 T cells in patients had a markedly impaired capacity to produce IFN-γ. Further in vitro and in vivo analysis showed that interferon-α, which was induced during HCV infection, caused Vδ2 T cell function bias toward cytotoxicity. These results suggest a functional dichotomy for Vδ2 T cells in chronic HCV infections: a role in cytotoxicity but not for IFN-γ production, which may contribute to both the liver inflammation and HCV persistence. PMID:27192960

  5. Combined exercise training reduces IFN-γ and IL-17 levels in the plasma and the supernatant of peripheral blood mononuclear cells in women with multiple sclerosis.

    PubMed

    Golzari, Zahra; Shabkhiz, Fatemeh; Soudi, Sara; Kordi, Mohammad Reza; Hashemi, Seyed Mahmoud

    2010-11-01

    Multiple sclerosis (MS) is a chronic inflammatory demyelinating disorder in which lymphocytic infiltration mediated mainly by pro-inflammatory cytokines. In this study, we examined the effect of combined exercise training on the levels of IFN-γ, IL-4 and IL-17 in the plasma and the supernatant of peripheral blood lymphocytes in women with multiple sclerosis. Expanded Disability Status Scale (EDSS), VO(2)max, muscle strength, and balance tests were obtained at baseline and post-treatment follow-up. Combined exercises training was designed for 24 sessions during 8 weeks. Each session was started with 5 min warm-up and was followed by 10 min stretch training, 20 min aerobic exercises and 20 min resistance-endurance training. The disability score was significantly decreased in test MS subjects after 8 weeks combined exercise training. Muscle strength and balance were increased significantly after the training program in test group. In this study, plasma, and peripheral blood mononuclear cell (PBMC) IL-17 and IFN-γ production was significantly decreased after 8 weeks combined training. Our findings suggest that combined training has useful anti-inflammatory effects by decrease in PBMC and plasma IL-17 production. PMID:20797460

  6. Control of RSV-induced lung injury by alternatively activated macrophages is IL-4R alpha-, TLR4-, and IFN-beta-dependent.

    PubMed

    Shirey, K A; Pletneva, L M; Puche, A C; Keegan, A D; Prince, G A; Blanco, J C G; Vogel, S N

    2010-05-01

    Severe respiratory syncytial virus (RSV)-induced bronchiolitis has been associated with a mixed "Th1" and "Th2" cytokine storm. We hypothesized that differentiation of "alternatively activated" macrophages (AA-M phi) would mediate the resolution of RSV-induced lung injury. RSV induced interleukin (IL)-4 and IL-13 by murine lung and peritoneal macrophages, IL-4R alpha/STAT6-dependent AA-M phi differentiation, and significantly enhanced inflammation in the lungs of IL-4R alpha(-/-) mice. Adoptive transfer of wildtype macrophages to IL-4R alpha(-/-) mice restored RSV-inducible AA-M phi phenotype and diminished lung pathology. RSV-infected Toll-like receptor (TLR)4(-/-) and interferon (IFN)-beta(-/-) macrophages and mice also failed to express AA-M phi markers, but exhibited sustained proinflammatory cytokine production (e.g., IL-12) in vitro and in vivo and epithelial damage in vivo. TLR4 signaling is required for peroxisome proliferator-activated receptor gamma expression, a DNA-binding protein that induces AA-M phi genes, whereas IFN-beta regulates IL-4, IL-13, IL-4R alpha, and IL-10 expression in response to RSV. RSV-infected cotton rats treated with a cyclooxygenase-2 inhibitor increased expression of lung AA-M phi. These data suggest new treatment strategies for RSV that promote AA-M phi differentiation. PMID:20404812

  7. Functional dichotomy of Vδ2 γδ T cells in chronic hepatitis C virus infections: role in cytotoxicity but not for IFN-γ production

    PubMed Central

    Yin, Wenwei; Tong, Shiwen; Zhang, Qiongfang; shao, Jianying; Liu, Qian; Peng, Hong; Hu, Huaidong; Peng, Mingli; Hu, Peng; Ren, Hong; Tian, Zhigang; Zhang, Dazhi

    2016-01-01

    Vδ2 γδ (Vδ2) T cells, a major human γδ T cell subset, exhibit broad anti-tumor and anti-infective activity; however, their precise role in chronic hepatitis C virus (HCV) infections remains unclear. In this study, we analyzed the phenotype and function of Vδ2 T cells in 43 HCV-infected patients compared to 39 healthy controls (HCs). Vδ2 T cells from HCV-infected patients were activated and differentiated into effector cells. Vδ2 T cells in patients expressed significantly higher levels of natural killer (NK) cell markers CD56 and CD16 than in HCs, acquiring cytotoxic NK-like phenotype. The Vδ2 T cell phenotype was associated with increased cytolytic effector molecules expression in HCV-infected patients with elevated serum ALT levels. Surprisingly, Vδ2 T cells in patients had a markedly impaired capacity to produce IFN-γ. Further in vitro and in vivo analysis showed that interferon-α, which was induced during HCV infection, caused Vδ2 T cell function bias toward cytotoxicity. These results suggest a functional dichotomy for Vδ2 T cells in chronic HCV infections: a role in cytotoxicity but not for IFN-γ production, which may contribute to both the liver inflammation and HCV persistence. PMID:27192960

  8. Modulation effect of Semen Ziziphi Spinosae extracts on IL-1β, IL-4, IL-6, IL-10, TNF-α and IFN-γ in mouse serum.

    PubMed

    Xie, Junbo; Guo, Li; Pang, Guangchang; Wu, Xin; Zhang, Mingchun

    2011-02-01

    This study aims to explore and evaluate the effects of Semen Ziziphi Spinosae extracts on the serum levels of interleukin (IL)-6, IFN-γ, IL-1β, TNF-α, IL-10 and IL-4 in mice, and the regulative effect of Semen Ziziphi Spinosae on the cytokine system. Using an ELISA assay, the serum levels of IL-6, IFN-γ, IL-1β, TNF-α, IL-10 and IL-4 were examined in mice after intraperitoneal injection (i.p.) with Semen Ziziphi Spinosae extracts. The results showed that the levels of IL-6 and IL-1β were significantly increased compared with the control groups (p<0.01), while the level of tumour necrosis factor-α (TNF-α) was significantly decreased (p<0.01). Semen Ziziphi Spinosae possesses certain modulation effects on cytokines, and the immuno-regulating function and hypnosis effects of Semen Ziziphi Spinosae may be relevant to these modulation effects on cytokines. PMID:21328141

  9. EBV-driven LMP1 and IFN-γ up-regulate PD-L1 in nasopharyngeal carcinoma: Implications for oncotargeted therapy