UNIPROT:P05231 - FACTA Search

Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P05231 (interleukin-6)
23,907 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Interferons (IFNs) originally described for antiviral activity have been reported to have pleiotropic effects, including the ability to induce interleukin-6 (IL-6) and IL-8 production in several cell types. IL-6 and IL-8 are proinflammatory cytokines and are known to be produced by a wide variety of cells, including human keratinocytes. In the present study, we sought to examine the effects of IFNs on IL-6 and IL-8 production from human keratinocytes. IFN-gamma (10-50 ng/ml) induced IL-6 and IL-8 production dose dependently, but no induction of IL-6 or IL-8 was observed with either IFN-alpha or IFN-beta. Because cytokines often work in a cascade fashion and keratinocytes are a source of primary cytokines, IL-1 alpha, and tumor necrosis factor-alpha (TNF-alpha), we examined whether combined treatment with IFN-gamma and these primary cytokines, IL-1 alpha and TNF-alpha, had a synergistic effect on the production of IL-6 and IL-8. Combined treatment with IFN-gamma and IL-1 alpha induced 6-fold to 7-fold higher levels of IL-6 than IL-1 alpha alone. Combined treatment with IFN-gamma and TNF-alpha induced 11-fold to 12-fold higher levels of IL-6 than TNF-alpha alone. The same treatment induced 3-fold to 4-fold higher levels of IL-8 in both cases. These results suggest that IFN-gamma is a positive regulator for the production of IL-6 and IL-8 from human keratinocytes and likely has an augmentative effect on skin inflammation.
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PMID:Effects of interferons on the production of interleukin-6 and interleukin-8 in human keratinocytes. 919 2

We have studied the expression of cytokines and viral genes induced by Newcastle disease virus (NDV) and Sendai virus in bone marrow-derived macrophages (BMM) and lymphocytes from C57BL/6 mice and the congenic line B6.C-H-28c. These mice carry the loci If-1h (high) or If-1l (low), respectively, that are responsible for up to tenfold differences in the interferon (IFN)-alpha, IFN-beta, interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) response to NDV but not to Sendai virus. Only BMM but not spleen lymphocytes showed allele-specific differences in NDV-induced cytokine levels, indicating cell-specific If-1 expression. The If-1 locus harbors IFN-inducible gene(s) whose expression is prevented in the presence of cycloheximide. Our data provide evidence that the If-1l allele acts by specifically suppressing the cytokine response to NDV. Cytokine production was dependent on infectious virions, and kinetic analyses revealed a close correlation between the amount of viral transcripts and individual cytokine mRNA. BMM from lf-1l mice strongly restricted transcription of the NDV nucleoprotein (NP) gene, whereas BMM from If-1h mice supported NP transcription. Following treatment with IL-4, which inhibited constitutive IFN-beta gene expression, however, If-1l BMM became highly permissive for transcription of the viral NP gene and released high amounts of cytokines. We conclude that If-1l gene products are responsible for the low producer phenotype by efficiently interfering with NDV transcription, leading to strongly reduced intracellular levels of cytokine inducing viral dsRNA intermediates.
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PMID:Interferon-induced expression of If-1h and If-1l alleles in Newcastle disease virus-infected mouse macrophages is associated with specific differences in viral gene transcription. 955 81

To compare virological, biochemical, and immune responses to human lymphoblastoid interferon (IFN-alpha) and human fibroblast interferon (IFN-beta) in patients with chronic hepatitis C virus (HCV) infection, 120 patients were randomly assigned to three groups (group A, 60 patients receiving IFN-alpha, 6 million units (MU) once a day, daily for one month and thrice weekly for five months; group B, 40 patients receiving 6 MU IFN-beta once a day daily for two months; and group C, 20 patients receiving 3 MU IFN-beta twice a day (6 MU/day) daily for two months). Serum soluble interleukin-2 receptor (sIL-2R) and interleukin-6 (IL-6) levels were measured by enzyme-linked immunosorbent assay. Patients with sustained clearance of serum HCV RNA detected by polymerase chain reaction (PCR) at six months after IFN treatment were defined as having complete response to IFN treatment. A low level of HCV RNA (< or = 10(4) copies/50 microl, measured by competitive PCR) and HCV RNA of genotype 2a were favorable factors for a complete response to both IFNs. Complete response in group A treatment was strongly associated with early HCV RNA clearance, in contrast with group B. A significantly higher HCV RNA negativity at the second week from start of treatment was noted in group C (80.0%), compared with groups A (41.6%) and B (27.5%). sIL-2R levels rose in each group during IFN administration. In group C, alanine aminotransferase (ALT) and IL-6 levels were remarkably elevated. These findings indicate that timing of serum HCV RNA negativity in sustained response differs between IFN-alpha and IFN-beta administrations and that early HCV RNA clearance was induced by twice-a-day IFN-beta treatment.
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PMID:Differences between interferon-alpha and -beta treatment for patients with chronic hepatitis C virus infection. 1008 Jan 58

We investigated the role of the constitutive nitric oxide (NO) in the expression of interferon (IFN) genes in mouse peritoneal macrophages (PM). The treatment of PM with L-arginine-N(G)-amine (AA), a potent inhibitor of NO-producing enzymes, resulted in a marked accumulation of IFN-alpha4 mRNA and, to a minor extent, of IFN-beta mRNA. In contrast, the expression of IFN-gamma mRNA, as well as tumor necrosis factor alpha and interleukin-6 mRNA, was not affected. Furthermore, a remarkable increase in the expression of the IFN regulating factor 1 (IRF-1), but not of IRF-2, mRNA was detected in AA-treated PM. To investigate whether the AA-induced activation of the IFN system correlates with the production and antiviral activity of IFN, the extent of encephalomyocarditis virus (EMCV) replication was monitored in AA-treated PM with respect to control cultures. AA treatment strongly inhibited, in a dose-dependent manner, EMCV yields in PM. Likewise, similar results were obtained by the addition of the NO-scavenger carboxyphenyl-tetramethylimidazoline-oxyl-oxide. In addition, inhibition of NO synthesis by N(G)-mono-methyl-L-arginine in PM strongly decreased virus replication in coculture of PM and EMCV-infected L929 cells, whereas no antiviral effect was observed in L929 cells alone. Moreover, the AA-mediated antiviral activity was abrogated in the presence of antibody to IFN-alpha/beta, whereas antibody to IFN-gamma was completely ineffective. Taken together, these results indicate that low levels of NO, constitutively released by resting PM, negatively regulate the expression and activity of IFN-alpha/beta in PM. We suggest that NO acts as a homeostatic agent in the regulation of IFN pathway expression in macrophages.
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PMID:Inhibitory activity of constitutive nitric oxide on the expression of alpha/beta interferon genes in murine peritoneal macrophages. 1043 21

Multiple sclerosis (MS) is a T-cell-mediated autoimmune demyelinating disease of the central nervous system, associated with an altered cytokine network. We previously assayed peripheral blood T-lymphocyte binding for two prototypic cytokines, tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6), and found that T cells from MS patients had significantly more TNF-alpha and IL-6 receptors than those from healthy controls. In the present work, paralleling a previous one on T-cell TNF-alpha binding, we studied the effect of interferon (IFN)-beta-1b treatment on T-lymphocyte IL-6 binding in patients with relapsing-remitting MS. T cells from MS patients had significantly (P < 0.001) higher amounts of IL-6 receptors than those from controls [292 +/- 6 vs. 228 +/- 8 (mean +/- SEM) receptors per cell, respectively], whereas the ligand-receptor affinity values were similar in the two groups [26.2 +/- 0.7 and 25.7 +/- 0.4 (mean +/- SEM) pmoles/l, respectively]. After a 3-month IFN-beta-1b treatment, they showed a significant decrease in IL-6 binding [266 +/- 7 (mean +/- SEM) receptors per cell]. After 6 and 9 months, T-cell IL-6 B(max) values were even lower [258 +/- 8 and 251 +/- 8 (mean +/- SEM) receptors per cell]. Since an increased IL-6 binding might be linked to a lymphocyte activation, our data give further support for an enhanced immune response in patients with MS. Our data seem to demonstrate that the major effects of IFN-beta-1b treatment result in a decrease of T-cell activation.
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PMID:T-cell interleukin-6 receptor binding in interferon-beta-1b-treated multiple sclerosis patients. 1113 50

Lassa virus (LV) and Mopeia virus (MV) are closely related members of the Arenavirus genus, sharing 75% amino acid sequence identity. However, LV causes hemorrhagic fever in humans and nonhuman primates, whereas MV cannot induce disease. We have previously shown that antigen-presenting cells (APC)-macrophages (MP) and dendritic cells (DC)-sustain high replication rates of LV but are not activated, suggesting that they play a role in the immunosuppression observed in severe cases of Lassa fever. Here, we infected human APC with MV and analyzed the cellular responses induced. MV infection was productive in MP and even more so in DC. Apoptosis was not induced in either cell type. Moreover, unlike DC, MP were early and strongly activated in response to MV, as shown by the increased surface expression of CD86, CD80, CD54, CD40, and HLA-abc and by the production of mRNA encoding alpha interferon (IFN-alpha), IFN-beta, tumor necrosis factor alpha and interleukin-6. In addition, MV-infected MP produced less of the virus than DC, which was related to the fact that these cells secreted IFN-alpha. Thus, the strong activation of MP is probably a major event in the control of MV infection and may be involved in the induction of an adaptive immune response in infected hosts. These results may explain the difference in pathogenicity between LV and MV.
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PMID:Human macrophages, but not dendritic cells, are activated and produce alpha/beta interferons in response to Mopeia virus infection. 1536 18

Cytokines play an important role in the onset, regulation, and propagation of immune and inflammatory responses within the central nervous system (CNS). The main source of cytokines in the CNS are microglial cells. Under inflammatory conditions, microglial cells are capable of producing pro- and antiinflammatory cytokines, which convey essential impact on the glial and neuronal environment. One paramount functional feature of astrocytes is their ability to form a functionally coupled syncytium. The structural link, which is responsible for the syncytial behavior of astrocytes, is provided by gap junctions. The present study was performed to evaluate the influence of inflammation related cytokines on an astroglial/microglial inflammatory model. Primary astrocytic cultures of newborn rats were cocultured with either 5% (M5) or 30% (M30) microglial cells and were incubated with the following proinflammatory cytokines: tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), interleukin-6 (IL-6), interferon-gamma (IFN-gamma), and the antiinflammatory cytokines transforming growth factor-beta1 (TGF-beta1) and IFN-beta. Under these conditions, i.e., incubation with the inflammatory cytokines and the high fraction of microglia (M30), microglial cells revealed a significant increase of activated round phagocytotic cells accompanied by a reduction of astroglial connexin 43 (Cx43) expression, a reduced functional coupling together with depolarization of the membrane resting potential (MRP). When the antiinflammatory mediator TGF-beta1 was added to proinflammatory altered M30 cocultures, a reversion of microglial activation and reconstitution of functional coupling together with recovery of the astroglial MRP was achieved. Finally IFN-beta, added to M5 cocultures was able to prevent the effects of the proinflammatory cytokines TNF-alpha, IL-1beta, and IFN-gamma.
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PMID:Effects of cytokines on microglial phenotypes and astroglial coupling in an inflammatory coculture model. 1592 Jul 25

Leptin is a peptide hormone which acts on cells of immune system by influencing the production of cytokines. Serum leptin levels and cytokine production by peripheral blood mononuclear cells (PBMC) were measured in 18 secondary progressive multiple sclerosis (SPMS) patients under IFN-beta-1b treatment. There were no overall effects on leptin, interleukin-6 (IL-6), IL-10 and IL-12 p40 after 2, 6 and 12 months of treatment. However, leptin and IL-6 decreased after 6 and 12 months of treatment in 12 patients who did not show progression of disability. Thus, our pilot data show that the beneficial effect of IFN-beta on some SPMS patients might be associated with the reduced levels of leptin and reduced IL-6 production by PBMC.
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PMID:Evidence of involvement of leptin and IL-6 peptides in the action of interferon-beta in secondary progressive multiple sclerosis. 1626 54

The V protein of parainfluenza virus 5 (PIV5) plays an important role in the evasion of host immune responses. The V protein blocks interferon (IFN) signaling in human cells by causing degradation of the STAT1 protein, a key component of IFN signaling, and blocks IFN-beta production by preventing nuclear translocation of IRF3, a key transcription factor for activating IFN-beta promoter. Interleukin-6 (IL-6), along with tumor necrosis factor (TNF)-alpha and IL-1beta, is a major proinflammatory cytokine that plays important roles in clearing virus infection through inflammatory responses. Many viruses have developed strategies to block IL-6 expression. Wild-type PIV5 infection induces little, if any, expression of cytokines such as IL-6 or TNF-alpha, whereas infection by a mutant PIV5 lacking the conserved C-terminal cysteine rich domain (rPIV5VDeltaC) induced high levels of IL-6 expression. Examination of mRNA levels of IL-6 indicated that the transcription activation of IL-6 played an important role in the increased IL-6 expression. Co-infection with wild-type PIV5 prevented the activation of IL-6 transcription by rPIV5VDeltaC, and a plasmid encoding the full-length PIV5 V protein prevented the activation of IL-6 promoter-driven reporter gene expression by rPIV5VDeltaC, indicating that the V protein played a role in inhibiting IL-6 transcription. The activation of IL-6 was independent of IFN-beta even though rPIV5VDeltaC-infected cells produced IFN-beta. Using reporter gene assays and chromatin immunoprecipitation (ChIP), it was found that NF-kappaB played an important role in activating expression of IL-6. We have proposed a model of activating and inhibiting IL-6 transcription by PIV5.
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PMID:Inhibition of interleukin-6 expression by the V protein of parainfluenza virus 5. 1769 82

The P8 proteoglycolipid complex (P8 PGLC) is a glyconjugate expressed by Leishmania mexicana complex parasites. We previously have shown that vaccination with P8 PGLC provides protection against cutaneous leishmaniasis in susceptible BALB/c mice. However, the biological importance of this complex remains unknown. Here we show that P8 PGLC localizes to the surface of Leishmania pifanoi amastigotes and that upon exposure to macrophages, P8 PGLC binds and induces inflammatory cytokine and chemokine mRNAs such as tumor necrosis factor alpha and RANTES early after stimulation. Our studies indicate that cytokine and chemokine induction is dependent upon Toll-like receptor 4 (TLR4). Interestingly, key inflammatory cytokines and chemokines (such as interleukin-6 [IL-6], macrophage inflammatory protein 1beta, and beta interferon [IFN-beta]) that can be induced through TLR4 activation were not induced or only slightly upregulated by P8 PGLC. Activation by P8 PGLC does not occur in the presence of TLR4 alone and requires both CD14 and myeloid differentiation protein 2 for signaling; this requirement may be responsible for the limited TLR4 response. This is the first characterization of a TLR4 ligand for Leishmania. In vitro experiments indicate that L. pifanoi amastigotes induce lower levels of cytokines in macrophages in the absence of TLR4; however, notably higher IL-10/IFN-gamma ratios were found for TLR4-deficient mice than for BALB/c mice. Further, increased levels of parasites persist in BALB/c mice deficient in TLR4. Taken together, these results suggest that TLR4 recognition of Leishmania pifanoi amastigotes is important for the control of infection and that this is mediated, in part, through the P8 PGLC.
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PMID:Leishmania pifanoi proteoglycolipid complex P8 induces macrophage cytokine production through Toll-like receptor 4. 1829 40

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