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Pharmacokinetics and tissue distribution of recombinant human alpha A, D, A/D(Bgl), and I interferons and mouse alpha-interferon in mice.

The pharmacokinetics and tissue distribution in mice of several recombinant human alpha-interferons [rHuIFN-alpha A, D, I, and A/D(Bgl)] as well as natural mouse alpha-interferon (MuIFN-alpha) were assessed following single intravenous injections. The serum profiles of rHuIFN-alpha A, rHuIFN-alpha D, rHuIFN-alpha A/D(Bgl), and MuIFN-alpha were similar, whereas those following rHuIFN-alpha I showed a much longer terminal elimination phase. Differences in elimination half-life, volume of distribution, and total body clearance between these IFNs were observed. There was appreciable uptake of IFN in the kidney: the amount of each interferon per gram of tissue in the kidney ranges from 1 to 9 times the amount found in the serum. The greatest uptake appeared with rHuIFN-alpha D, followed by rHuIFN-alpha A, rHuIFN-alpha A/D(Bgl), and MuIFN-alpha. The only exception was rHuIFN-alpha I which showed no uptake into the kidney.

Animals↗

Characterization of a mouse interferon gene locus II. Differential expression of alpha-interferon genes.

A cluster of four MuIFN-alpha genes was recently isolated and characterized (1); one of the genes in this cluster had, in the coding region, an internal deletion of 5 amino acids. Bacterial expression plasmids were constructed to examine the effect of this deletion on the antiviral activity of the MuIFN-alpha 4 peptide and it was found that the alpha 4 interferon peptide had a 100-fold lower antiviral activity than full length alpha-interferon proteins when expressed in E. coli. Three of the four MuIFN-alpha genes identified were expressed coordinately in L-cells infected with NDV. The relative levels of alpha 4 mRNA were substantially higher than the levels of the other alpha mRNAs. Comparison of the 5' end flanking sequences of these four alpha interferon genes revealed that the promoter sequences of alpha 1, alpha 5 and alpha 6 are more homologous to each other than to the alpha 4 promoter which also contains a G rich cluster not seen in the other three promoters.

Animals↗

Differential sensitivity of Rauscher murine leukaemia virus (MuLV-R) to interferons in two interferon-responsive cell lines.

The effect of interferon on the replication of vesicular stomatitis virus (VSV) and type-C oncornavirus in two Balb/c mouse cell lines, JLS-V5 and JLS-V9R, infected with MuLV-R was examined. VSV replication was inhibited threefold (0-5 log10) in both cell lines by 10 to 20 units of interferon/ml. In JLS-V5 cells C-type virus yields, as measured by 3H-uridine incorporation and reverse transcriptase activity, were also reduced threefold by 10 to 20 units of interferon/ml. However, in JLS-V9R cells, C-type virus replication was refractory to interferon at concentrations up to 1 x 10(4) units/ml. Infectious C-type virus transmitted from JLS-V9R cells to Balb/3TS cells was as sensitive to interferon as virus transmitted from JLS-V5 cells, indicating that resistance of C-type virus in JLS-V9R cells is a feature of the cells rather than of the virus strain.

Animals↗

Comparison of interferon action in interferon resistant and sensitive L1210 cells.

Translation inhibition, leu-tRNA aminoacylation and double-stranded RNA and ATP dependent phosphorylation were examined in interferon-treated and control cell-free lysates of leukaemic mouse L 1210 R and L 1210 S cells. No differences were observed between the respective interferon-treated and control cell-free extracts, except for the presence of an enhanced 67K dalton phosphoprotein fraction in interferon-treated L 1210 S cell-free extracts. In non-responding cell-free lysates, the lack of stimulation of a 67K dalton phosphoprotein fraction cannot be explained by the presence of an increased level of some inhibitory activity, such as a phosphatase.

Animals↗

Regulation of the interferon system: evidence that Vero cells have a genetic defect in interferon production.

A clone of Vero cells was isolated and shown to be totally unable to synthesize interferon and insensitive to the toxic effect of poly(rI).poly(rC) treatment. Cells of this clone and mouse L cells were fused by treatment with polyethylene glycol or Sendai virus. Hybrid cell clones were isolated following selection in medium containing hypoxanthine, thymidine and ouabain. The hybrids were sensitive to the antiviral effect of poly(rI).poly(rC) and synthesized mouse, but not primate, interferon. It is proposed that in Vero cells, the gene for interferon synthesis is defective or absent.

Animals↗

Interferon induction by viruses. Sindbis virus: defective-interfering particles temperature-sensitive for interferon induction.

A defective-interfering (DI) particle of Sindbis virus was generated from a ts mutant of RNA-complementation group A by serially undiluted passages at 30 degrees C. This mutant induced interferon at a permissive temperature (30 degrees C), but not at a non-permissive temperature (40.5 degrees C); it also expressed homotypic interference throughout the range 30 to 40.5 degrees C. This demonstrates for the first time in a DI particle a ts function, namely, the ability to induce interferon. In addition, our data provide further evidence that the RNA genome of a Sindbis DI particle can be translated within the cell. We postulate that the products of translation function to produce the putative inducer of interferon, namely a molecule of dsRNA.

Defective Viruses↗

The effect of hypertonic salt on interferon and interferon mRNA synthesis in human MG63 cells.

After infection with Sendai virus or Newcastle disease virus (NDV) strain F, human osteosarcoma MG63 cells produced large amounts of interferon-beta. Both interferon production and overall protein synthesis were strongly inhibited by hypertonic salt. Interferon mRNA synthesis, however, was little affected by hypertonic salt up to twice normal salt concentrations, although cellular RNA synthesis was inhibited under these conditions. The results are compared to those obtained with polyriboinosinic acid: polyribocytidylic acid copolymer [poly(rI) . poly(rC)] inductions of MG63 cells.

Cell Line↗

Studies on the expression of spontaneous and induced interferons in mouse peritoneal macrophages by means of monoclonal antibodies to mouse interferons.

Monoclonal antibodies (MAbs) to mouse interferons (MuIFN) have been used to characterize the interferon-like activities spontaneously expressed in mouse peritoneal macrophages freshly explanted from normal pathogen-free mice. Injection of mice with MAbs to MuIFN-alpha or -beta resulted in a significant increase of vesicular stomatitis virus (VSV) multiplication in peritoneal macrophages. Addition of these MAbs to freshly explanted mouse macrophages accelerated the decay of the antiviral state to VSV during the 'ageing' in vitro of these macrophage cultures. Furthermore, these MAbs to MuIFN-alpha or -beta markedly inhibited the transfer of the antiviral state from freshly explanted peritoneal cells or macrophages to syngeneic macrophages 'aged' in vitro permissive for virus replication. These effects were not observed using a non-neutralizing antibody to MuIFN-alpha, nor with a MAb to MuIFN-gamma. In all experiments sheep polyclonal antibodies to MuIFN-alpha/beta were more effective than the corresponding amount of MAbs to MuIFN-alpha or -beta. A mixture of both these MAbs was more effective than either alone. Interferons produced after stimulation of peritoneal macrophages with Newcastle disease virus (NDV) and of total peritoneal cells with lipopolysaccharides (LPS) have also been characterized by means of MAbs to IFNs. The results of neutralization studies with these antibodies indicated that MuIFN-beta was the major component of peritoneal cell IFN (induced by both NDV and LPS) and MuIFN-alpha was a minor component (13 to 17%). These data indicate that both MuIFN-alpha and -beta, but not MuIFN-gamma, are spontaneously present in/on mouse peritoneal macrophages and are produced after stimulation with NDV or LPS.

Animals↗

Type-A CpG oligonucleotides activate exclusively porcine natural interferon-producing cells to secrete interferon-alpha, tumour necrosis factor-alpha and interleukin-12.

Natural interferon-producing cells (NIPC), also referred to as immature plasmacytoid dendritic cells (PDC), constitute a small population of leucocytes secreting high levels of type I interferons in response to certain danger signals. Amongst these signals are those from DNA containing unmethylated CpG motifs. The present work demonstrated that the CpG oligonucleotides (CpG-ODN) 2216, D32 and D19 induce high amounts of interferon-alpha (IFN-alpha), tumour-necrosis factor-alpha (TNF-alpha) and interleukin (IL)-12 in porcine peripheral blood mononuclear cells (PBMCs). Swine workshop cluster 3 (SWC3)1ow CD4high cells, with high IL-3-binding activity, representing NIPC, were the exclusive cytokine-producing cells responding to the CpG-ODN. These cells did not express CD6, CD8 or CD45RA. Importantly, monocyte-derived DC did not respond to CpG-ODN by secretion of IFN-alpha or TNF-alpha or by the up-regulation of costimulatory molecule expression. CpG-ODN up-regulated MHC class II and CD80\86 expression on the NIPC, but were unable to promote NIPC survival. Interestingly, certain CpG-ODN, incapable of inducing NIPC to secrete IFN-alpha or up-regulate MHC class II and CD80\86, did promote NIPC viability. Taken together, the influence of CpG-ODN on porcine NIPC, monocytes and myeloid DCs relates to that observed with their human equivalents. These results represent an important basis for the application of CpG-ODN as adjuvants for the formulation of novel vaccines and demonstrate the importance of the pig as an alternative animal model for this approach.

Animals↗

Transcriptional activation of psoriasis-associated cytokeratin K17 by interferon-gamma. Analysis of gamma-interferon activation sites.

The acid cytokeratin K17 is inducible by interferon-gamma (IFN-gamma), a characteristic unique for cytokeratins analysed so far. In this report, we analysed the molecular basis of K17 expression by IFN-gamma in epithelial cells. The 5'-flanking region of the K17 gene (positions -1762 to -13), cloned in front of a chloramphenicol acetyl transferase (CAT) reporter gene construct, conferred responsiveness to IFN-gamma but not IFN-alpha in transient transfection assays. Sequence analysis revealed three putative gamma-interferon activation sites (GAS). Band-shift assays and transient transfections with CAT reporter gene constructs were used to characterize and to dissect the functional importance of each of the putative GAS elements. In the band shift assay, GAS3 (positions -1528 to -1515) was found to bind GAF/STAT91 and to compete with tryptophanyl-tRNA synthetase (IFP53/WRS)-GAS for binding to GAF; in contrast, GAS1 (positions -183 to -171) and GAS2 (positions -290 to -277) were neither able to bind to nor to compete for GAF/STAT91. However, deletion constructs and mutational analysis of CAT reporter gene constructs harbouring the 5'-flanking region (positions -1762 to -111) in front of the heterologous promoter revealed that the distal GAS3 site was dispensible, but that alteration of the GAS1 element rendered the promoter uninducible by IFN-gamma. Surprisingly, transfection of a CAT-reporter gene construct harbouring a promoter segment (positions -111 to +13) devoid of the GAS elements revealed enhanced CAT-gene expression upon IFN-gamma treatment. The interaction of GAS1 with the interferon-responsive promoter region in the physiological context remains to be clarified.

Base Sequence↗

Human interferon and cell growth inhibition. I. Inhibitory effect of human interferon on the growth rate of cultured human cells.

Human interferon inhibited the growth rate of cultured human cells. These included diploid fibroblast cells from embryonal lung and skin, established lines of HeLa and U-amnion cells, all grown in monolayer; and the established lymphoblastoid line P3HR1 grown in suspension. Cells growing fast were inhibited to a higher degree than those growing slowly. The inhibitory effect was dose dependent but the dose-dependency was different in various cell types. The inhibitory effect of leukocyte interferon and fibroblast interferon was quantitatively comparable.

Cell Count↗

Interferon-gamma-inducing factor (IL-18) and interferon-gamma in inflammatory CNS diseases.

OBJECTIVE: To examine the intrathecal production of a newly identified cytokine, interferon-gamma-inducing factor (IL-18), together with interferon-gamma itself, in inflammatory diseases of the CNS (i.e., bacterial meningitis, viral meningoencephalitis, and MS). RESULTS: IL-18 concentrations in CSF were significantly increased in bacterial meningitis and tended toward increased levels in viral meningoencephalitis. In contrast, IL-18 was detectable only in a few patients with MS and healthy controls. Interestingly, interferon-gamma was significantly increased selectively in CSF of patients with viral meningoencephalitis. CONCLUSION: The observation of an intrathecal release of IL-18 in patients with meningitis argues for a pathophysiologic role of this novel cytokine in immunity against invading microorganisms the CNS.

Adult↗

Effect of interferon-alpha on progression of cirrhosis to hepatocellular carcinoma: a retrospective cohort study. International Interferon-alpha Hepatocellular Carcinoma Study Group.

BACKGROUND: There is debate about whether interferon-alpha treatment lowers the risk of progression to hepatocellular carcinoma in patients with chronic viral hepatitis and cirrhosis and whether any effect is limited to certain subgroups. We investigated these issues by retrospective analysis of data for 913 patients from Italy and Argentina. METHODS: 21 centres reported patients from their records who had chronic viral hepatitis and Child's A cirrhosis, were positive for HBsAg or hepatitis-C-virus antibodies (anti-HCV), and had been screened yearly for at least 3 years by ultrasonography and alpha-1-fetoprotein testing. Prognostic risk factors for hepatocellular carcinoma defined by multivariate Cox regression analysis and individual observation time were used for group matching and conditional logistic regression analysis of the independent interferon-alpha treatment effect. FINDINGS: After group matching, the number of patients was reduced to 637. Age, male sex, and portal hypertension were significant risk factors for hepatocellular carcinoma (each p < 0.001); hepatic inflammation (p = 0.21) and iron storage (p = 0.18) were also included in the model 66 (19%) of 356 untreated patients and 29 (10%) of 281 treated patients developed hepatocellular carcinoma (relative risk 1.99 [95% CI 1.09-3.64]); the corresponding proportions for anti-HCV-positive patients were 48 (18.5%) of 259 versus 21 (9.1%) of 232 (3.14 [1.46-6.80]), and those for hepatitis-B-virus-infected (HBV) patients were 18 (10%) of 97 and eight (16%) of 49 (0.98 [0.33-2.92]). Among anti-HCV patients without HBV markers, 29 (20%) of 129 untreated and six (5%) of 116 treated patients developed hepatocellular carcinoma (6.28 [1.65-23.8]). INTERPRETATION: Interferon treatment lowered the rate of progression to hepatocellular carcinoma two fold. The risk reduction was apparently greater for patients with chronic hepatitis C and no evidence of HBV infection. Future studies should stratify HCV-infected patients by HBV status.

Adolescent↗

Interferon versus interferon and UDCA combined therapy in chronic hepatitis C.

BACKGROUND: Interferon alpha (IFN) has been shown to have established efficacy in the treatment of chronic hepatitis C but its effectiveness is unsatisfactory. Combined therapies with IFN and other antiviral or immunomodulatory drugs are under evaluation. A combination of interferon alpha and ursodeoxycholic acid UDCA has been reported to give better results than interferon alone. The aim of the study was to assess the efficacy of IFN monotherapy versus IFN and UDCA therapy in patients with chronic hepatitis C. MATERIAL AND METHODS: We studied 38 patients (25 males and 13 females) chronically infected with HCV (anti-HCV positive, HCV-RNA positive by PCR). Seventeen of them were treated with IFN 3 MU tiw for 6 months--Group I. The remaining 21 patients were treated with IFN, at the same dosage, plus UDCA (10 mg/kg/day) also for 6 months--Group II. Patients were followed for 6 months. 6 months after the end of therapy, laboratory biochemical parameters, HCV viremia and proportion as well as time to relapse were assessed. CONCLUSIONS: In contrast to previous reports we did not find any differences neither in proportion of HCV reactivation nor in the time of its appearance among patients treated because of chronic hepatitis B with IFN alone or with IFN plus UDCA combined therapy. We also did not find any difference in initial and late response to the treatments in both groups.

DNA, Complementary↗

Study of the priming effect of interferon in L cells. I. The primed interferon response and the kinetics of development of priming.

Interferon was detected one hour earlier, its production followed an enhanced pattern and became resistant to actinomycin D 30 minutes sooner in cultures primed by interferon pretreatment before stimulation by polyriboinosinic-polyribocytidylic acid than in unprimed cultures. The kinetics of development of the primed state was found to be a time and dose dependent phenomenon. The continuous presence of interferon during the pretreatment period was not required for the development of the primed state.

Animals↗