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At least 163 records · Page 9Linked to original sources
PubMed2002

Substance P enhances the production of interferon-induced protein of 10 kDa by human keratinocytes in synergy with interferon-gamma.

A neuropeptide substance P is related to skin inflammation. Interferon-induced protein of 10 kDa (IP-10) chemoattracts T helper 1 cells, and interferon-induced protein of 10 kDa production by keratinocytes is enhanced in inflammatory skin diseases such as psoriasis. We examined the in vitro effects of substance P on interferon-induced protein of 10 kDa production by human keratinocytes. Though substance P alone did not induce interferon-induced protein of 10 kDa production, it enhanced interferon-induced protein of 10 kDa secretion, mRNA expression, and promoter activity induced by suboptimal concentrations of interferon-gamma. Interferon-stimulated response element and two nuclear factor-kappaB sites on interferon-induced protein of 10 kDa promoter were responsible for the enhancement by substance P. Substance P alone enhanced transcriptional activity and transcription factor binding through the two nuclear factor-kappaB sites, whereas it did not alter interferon-gamma-induced transcriptional activity and transcription factor binding through interferon-stimulated response element. The effects of substance P on interferon-induced protein of 10 kDa production and nuclear factor-kappaB activation were inhibited by neurokinin-1 receptor antagonist, phospholipase C inhibitor, intracellular Ca2+ chelator, and anti-oxidant. These results suggest that substance P may induce nuclear factor-kappaB activation and interferon-induced protein of 10 kDa production in synergy with interferon-gamma via neurokinin-1 receptor on keratinocytes. These effects of substance P may be mediated via phospholipase C activation, intra-cellular Ca2+ signal, and reactive oxygen intermediates.

Antineoplastic Agents↗
PubMed1988

Resistance to recombinant interferon alfa-2a in hairy-cell leukemia associated with neutralizing anti-interferon antibodies.

To explain the hematologic deterioration occasionally observed during interferon therapy, we assayed serum specimens from 51 patients with hairy-cell leukemia receiving treatment with recombinant interferon alfa-2a for the presence of anti-interferon antibodies. After a median of seven months of therapy, anti-interferon antibodies were found in 31 patients. Fifteen of these patients had only non-neutralizing antibodies, but antibody from the other 16 neutralized the antiviral effects of recombinant interferon alfa-2a in vitro. In no case, however, did neutralizing antibody inhibit the antiviral effects of purified natural interferon alfa. Clinical resistance to interferon of various degrees was present in 6 of 16 patients with neutralizing antibodies; the remaining 10 patients and all 20 patients without antibody continue to respond after a minimum of two years of therapy. In all the patients with interferon resistance, antibody was present when it developed. These data suggest that the development of clinical resistance to interferon alfa-2a in hairy-cell leukemia is not necessarily related to an altered cellular response to interferon. Treatment with other interferons, such as purified natural interferon alfa, may be useful in patients with clinically important neutralizing antibodies against interferon alfa-2a.

Antibodies↗
PubMed1977

Interferon messenger RNA content of human fibroblasts during induction, shutoff, and superinduction of interferon production.

Translation of injected mRNA in oocytes of Xenopus laevis has been used as a highly sensitive and quantitative assay for interferon mRNA. Injection into oocytes of polyadenylylated RNA extracted from poly(I).poly(C)-induced human diploid fibroblasts (FS-4) leads to the synthesis of biologically active human fibroblast interferon over a period of 24-32 hr. There is a linear relationship between the amount of mRNA injected and the interferon yield obtained over a range of 1-20 ng of injected RNA. Injection of 40-80 ng of mRNA into each of 15 oocytes, homogenized in 0.3 ml of incubation medium, gave a titer of 128-256 interferon reference units/ml of homogenate.FS-4 cells at the peak of interferon production-i.e., approximately 2.5 hr after the beginning of induction with poly(I).poly(C)-gave mRNA that yielded 24-48 interferon reference units/ml in the oocyte assay (30 ng of RNA injected per oocyte). An equivalent amount of mRNA from FS-4 cells in the shutoff phase, approximately 6 hr after induction, gave </=4 interferon reference units/ml. In contrast, mRNA extracted from FS-4 cells that had been induced and maintained in the presence of 40 muM 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole for 6 hr produced 64-128 interferon reference units/ml. Polyadenylylated RNA obtained from uninduced FS-4 cells did not lead to detectable interferon synthesis (<4 interferon reference units/ml). These data provide a direct verification of the hypothesis that the shutoff of interferon production in FS-4 cells involves a regulatory event leading to the posttranscriptional inactivation or degradation of interferon mRNA. Because the inactivating mechanism is sensitive to inhibition by 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole, a selective inhibitor of nuclear heterogeneous RNA and mRNA synthesis, it is likely that synthesis of an RNA molecule is necessary for the shutoff of interferon production.

Animals↗
PubMed1999

Changes in serum hepatitis C virus RNA in interferon nonresponders retreated with interferon plus ribavirin: a preliminary report.

Ribavirin, a nucleoside analogue, inhibits replication of RNA and DNA viruses and may control hepatitis C virus (HCV) infection through modulation of anti-inflammatory and antiviral actions. Ribavirin monotherapy has no effect on serum HCV RNA levels. In combination with interferon, this agent appears to enhance the efficacy of interferon. The aim of this study was to monitor serum HCV RNA levels early during therapy with interferon and ribavirin compared with that previously seen in the same patients during interferon monotherapy. Five patients who previously showed no response to therapy with interferon alfa 3 MU three times weekly for 6 months were retreated with the identical dose of interferon alfa 2b in combination with oral ribavirin 1,000 mg/day. Serum HCV RNA levels were monitored at baseline, week 4, week 8, and week 12 of therapy by a quantitative multicycle polymerase chain reaction assay. In the first 8 to 12 weeks, serum HCV RNA levels showed a greater decrease in all patients when retreated with combination therapy compared with interferon alone. Mean (+/- SEM) serum HCV RNA levels for interferon therapy alone were 3.3 +/- 0.95, 1.2 +/- 0.95, 1.6 +/- 1.2, and 2.3 +/- 1.2 x 10(6) copies/ml at week 0, 4, 8, and 12, respectively. This was compared with 3.3 +/- 0.83, 0.3 +/- 0.2, 0.03 +/- 0.02, and 0.15 +/- 0.14 x 10(6), respectively, for the interferon and ribavirin group (p < 0.07 at week 8). Two of five patients had undetectable serum HCV RNA during combination therapy. Combination therapy with interferon and ribavirin in prior interferon nonresponders reduces serum HCV RNA levels compared with interferon alone. This may suggest some additional antiviral effect of ribavirin when given with interferon.

Adult↗
PubMed2002

Treatment of hepatitis C virus genotype 4-related cirrhosis: ribavirin and interferon combination compared with interferon alone.

BACKGROUND: Response to treatment with interferon alfa, with or without concomitant ribavirin, varies with the viral genotype and the degree of fibrosis in patients with chronic hepatitis C virus (HCV). GOALS: To determine the response of HCV type 4-related cirrhosis to interferon and ribavirin combination treatment compared with interferon alone. STUDY: Patients living in Kuwait were assigned to take either interferon alone at a dosage of 5 million units thrice weekly (26 patients) or interferon 5 million units thrice weekly combined with ribavirin 1,000 mg/d (21 patients) for 24 weeks. Biochemical response was defined as normal alanine aminotransferase (ALT) at end of therapy. Sustained biochemical response was defined as normal ALT 6 months after the end of therapy. Sustained virologic response was defined as negative serum HCV RNA 6 months after the end of therapy. RESULTS: Only 2 (8%) of 26 patients showed biochemical response after interferon alone, whereas 11 (52%) of 21 showed biochemical response after interferon combined with ribavirin (p < 0.01). Only 2 (8%) of 26 patients showed sustained biochemical response after interferon alone, whereas 5 (23%) of 21 showed sustained biochemical response after interferon combined with ribavirin (not significant, p > 0.1). None of the 26 patients showed virologic response after interferon alone, whereas 3 (14%) of 21 showed sustained virologic response after interferon combined with ribavirin (not significant, p > 0.1). CONCLUSION: These results suggest that patients with cirrhosis caused by HCV type 4 show no response to interferon alone and only slightly better response to 24 weeks of interferon combined with ribavirin.

Adult↗
PubMed2001

The interferon inhibiting cytokine IK is overexpressed in cutaneous T cell lymphoma derived tumor cells that fail to upregulate major histocompatibility complex class II upon interferon-gamma stimulation.

Cutaneous T cell lymphomas are characterized by an accumulation of malignant clonal lymphocytes in the skin and occasionally in the blood. We compared gene transcription profiles from cultured clonal lymphocytes with autologous healthy blood lymphocytes by microarray hybridization. Cutaneous T cell lymphoma derived cells transcribed high amounts of an interferon inhibiting cytokine factor. The presence of an interferon inhibiting cytokine factor was confirmed in 12 skin biopsies of mycosis fungoides and Sézary syndrome derived blood lymphocytes by reverse transcriptase-polymerase chain reaction. The presence of interferon inhibiting cytokine factor mRNA in Sézary syndrome derived lymphocytes was associated with a lack of HLA class II upregulation after stimulation with interferon-alpha and interferon-gamma. This was not due to a loss of the interferon signaling cascade as the presence of interferon-signaling components was confirmed by reverse transcriptase--polymerase chain reaction on the transcriptional level. The elevated constitutive interferon inhibiting cytokine factor expression observed in cutaneous T cell lymphoma derived cells was insensitive to interferon-gamma stimulation, but was enhanced in normal peripheral blood mononuclear cells. We suggest that interferon inhibiting cytokine factor contributes to the lack of HLA class II upregulation in lymphoma cells. Interferon inhibiting cytokine factor may participate in providing a microenvironment at the tumor site insensitive to interferon-gamma stimulation and thus prevents an efficient local immune response.

Adult↗
PubMed1999

T-cell interferon gamma receptor binding in interferon beta-1b-treated patients with multiple sclerosis.

OBJECTIVE: To investigate the effects of interferon beta treatment on T-cell interferon gamma binding (which is a possible marker for T-cell-dependent immune function) in patients with multiple sclerosis (MS). DESIGN: Assay interferon gamma binding on T lymphocytes from patients with stable relapsing-remitting MS before, 3 months after, and 6 months after initiating interferon beta-1b treatment. SETTING: The study was performed on ambulatory patients in a tertiary care center, where patients were diagnosed as having definite MS. PATIENTS: Eighteen patients with clinically definite, stable, relapsing-remitting MS (13 women and 5 men; mean age [+/-SD] 32.6+/-7.1 years) were selected consecutively. Clinical status was defined according to the Kurtzke Expanded Disability Status Scale. All patients were treated with 8 x 10(6) IU interferon beta-1b subcutaneously every other day. Eighteen age- and sex-matched healthy subjects with no family history of neuropsychiatric disorders formed the control group. RESULTS: T lymphocytes from untreated patients with MS had significantly smaller amounts of interferon gamma receptors than those from control subjects (638+/-7 [SE] vs 707+/-11 [SE] receptors per cell). After 3 months of interferon beta-1b treatment, they showed a significant increase in interferon gamma binding (681+/-9 [SE] receptors per cell). After 6 months, T-cell interferon gamma maximal receptor values were even higher (700+/-7 [SE] receptors per cell), only slightly lower than those of control subjects. CONCLUSION: Given that reduced interferon gamma binding might be related to lymphocyte activation, our data seem to demonstrate that the major effect of interferon beta-lb treatment is a decrease in T-cell activation.

Adjuvants, Immunologic↗
PubMed1997

Platelet and white blood cell counts during therapy with different types of alpha interferon in patients with chronic viral hepatitis. Investigators of the Alpha Interferon Study Group of Piemonte, Italy.

BACKGROUND: Platelet and white blood cell counts decrease in chronic viral hepatitis patients treated with alpha interferon. AIM: To analyse whether delta negative variations in platelets and white blood cells are influenced by type, dose and duration of alpha interferon treatment, we studied 340 consecutive patients (mean treatment 8 months, range 4-18 months). PATIENTS AND METHODS: A total of 204 (60%) patients were treated with recombinant alpha interferons (30% alpha-2a and 30% alpha-2b), 64 (19%) with N3.leukocytic and 72 (21%) N1.lymphoblastoid natural interferons. Median age and male/female ratios were comparable in the 3 groups (41, 41 and 43 years and 2.3, 2.6 and 2.5, respectively). The lowest platelets and white blood cells counts were observed between the 2nd and the 4th month of therapy in all patients. Age, sex, aetiology and duration of interferon therapy did nor influence the platelets and white blood cells reduction rates. The decrease was lower for patients treated with N3.leukocytic interferon than for the other interferons. A significant difference was observed between interferon doses when the groups treated with 3 or 9-10 MIU were compared. However, dose or cirrhosis-related bias are ruled out by similar proportions of cirrhosis and patients treated with 3 MIU in the 3 groups of patients treated with different types of interferon. CONCLUSIONS: The type of interferon appears to represent a major cause of the different haemopoietic toxicity. The lowest toxicity of N3.leukocytic interferon may have clinical implications for the choice of interferon in patients with low baseline platelets and white blood cells counts. These findings prompt prospective studies on larger series of patients.

Adult↗
PubMedDate not supplied

[The effect of exogenous interferon on the in vitro production of alpha- and gamma-interferon by the lymphocytes of patients with respiratory papillomatosis].

The influence of various interferon concentrations in vitro on alpha- and gamma-interferon production by lymphocytes of children suffering from respiratory papillomatosis was studied for optimization of interferon therapy. Most of the children with clinical improvement after interferon treatment showed proportional dependence of alpha-interferon production upon exogenous interferon concentrations and stability of gamma-interferon production. In children without clinical improvement, initial production of both interferons was reduced significantly in the absence of IF in the medium, but no changes occurred when exogenous interferon was present in the medium. The test proposed here may be used for the determination of patients' sensitivity to interferon and for individualization of interferon treatment schedules in other long-lasting recurrent diseases.

Cells, Cultured↗
PubMed1995

Recombinant duck interferon: a new reagent for studying the mode of interferon action against hepatitis B virus.

Although interferon is widely used to treat chronic hepatitis B virus infections, its mode of action against hepadnaviruses is largely unknown. This deficit is due mainly to the lack of suitable model systems. The duck system could not be used because purified duck interferon was not available in sufficient quantities. We have now cloned a DNA fragment that contains an intronless gene for duck interferon. The primary translation product consists of 191 amino acids, the N-terminal 30 residues of which constitute a signal peptide. Mature duck interferon is 50% identical to the recently cloned chicken interferon. Sequence homology to mammalian interferons is marginal, but conservation of four cysteine residues and inducibility by virus indicate a distant relationship between duck interferon and mammalian type I interferons. Purified recombinant duck interferon from Escherichia coli is biologically active: it activates the interferon-inducible Mx gene, prevents cell destruction by cytolytic RNA viruses, and has a strong inhibitory effect on duck hepatitis B virus in cultured primary duck hepatocytes. This new reagent should help to define the interferon-sensitive step of the hepadnavirus life cycle. Furthermore, the duck system can now be used for systematic studies of the in vivo effectiveness of interferon in chronic hepatitis B virus infections.

Amino Acid Sequence↗
PubMed1986

Interferon modulation of c-myc expression in cloned Daudi cells: relationship to the phenotype of interferon resistance.

Treatment of interferon-sensitive Daudi cell with electrophoretically pure human interferon alpha markedly reduced the level of c-myc mRNA, increased the level of class I histocompatibility antigen (HLA) mRNA, and did not affect the level of actin mRNA within the same cells. In contrast, the level of c-myc mRNA or HLA mRNA did not change significantly following interferon treatment in different clones of Daudi cells selected for resistance to the antiproliferative action of interferon. These cells possessed interferon receptors, however, and responded to interferon modulation of other genes, including 2',5' oligoisoadenylate synthetase (M. G. Tovey, M. Dron, K. E. Mogensen, B. Lebleu, N. Metchi, and J. Begon-Lours, Guymarho, J. Gen. Virol., 64:2649-2653, 1983; M. Dron, M. G. Tovey, and P. Eid, J. Gen. Virol., 66:787-795, 1985). A clone of interferon-resistant Daudi cells which had reverted to almost complete sensitivity to both the antiproliferative action of interferon and the interferon-enhanced expression of HLA mRNA remained refractory, however, to interferon modulation of c-myc expression, suggesting that a reduced level of c-myc mRNA may not be a prerequisite for inhibition of cell proliferation in interferon-treated cells. Our results do not exclude the possibility, however, that posttranscriptional modification(s) of c-myc expression may precede an inhibition of cell proliferation in interferon-treated cells.

Cell Line↗
PubMed1984

The kinetics of interferon clearance in mice: comparison of mouse and human interferon.

Mice were injected with three kinds of interferon, i.e., mouse, human leucocyte and human fibroblast interferon, and the kinetics of their clearance from the blood was compared. After intravenous injection, mouse interferon was cleared very rapidly with an initial half life to two to three minutes, while both types of human interferon were cleared rather slowly with a corresponding value of about 20 minutes. When mouse interferon was injected intramuscularly or intraperitoneally, only very low levels of interferon activity were detected in the serum, and the recovery did not exceed 1% at any time. In contrast, both types of human interferon gave appreciable levels of activity in the serum upon injection by the same routes, and the levels remained stable during the observation period. The recovery of human interferon in the blood was about 10-fold that of mouse interferon. Mouse interferon was not inactivated in vitro by incubation with normal mouse serum. Our results suggest the validity of using homologous interferon for studies on the kinetics of interferon clearance in experimental animals.

Animals↗
PubMed1997

Interferon regulatory factor 1 induces the expression of the interferon-stimulated genes.

The interferon regulatory factor 1 (IRF-1) is a positive transcriptional regulatory protein which acts in the interferon signal transduction pathway to activate the transcription of the type I interferon genes by binding to the PRDI response element. The aim of this study was to explore the role of IRF-1 in regulating the expression of other interferon-stimulated genes in the interferon signal transduction pathway. A transient transfection assay was used to show that IRF-1 induced the expression of interferon-stimulated genes. The induction was a direct result of IRF-1 binding to the promoters of the interferon-stimulated response element (ISRE). The levels of endogenous mRNA of two interferon-stimulated genes, 6-16 and 9-27, were increased in cells containing increased levels of IRF-1. In addition, IRF-1 activates the expression of IRF-2, a negative regulator of the type I interferon genes themselves. Two sequences were found in the IRF-2 promoter which were the binding sites for IRF-1. Mutations in the oligonucleotide sequences of these sites could abolish the binding of the IRF-1. These data suggested that IRF-1 not only plays an important role in the induction of type I interferon genes, but also in the activation of interferon-stimulated genes.

Base Sequence↗
PubMed1995

The myxoma virus-soluble interferon-gamma receptor homolog, M-T7, inhibits interferon-gamma in a species-specific manner.

The myxoma virus M-T7 protein contains significant sequence similarity to the ligand binding domain of the mammalian interferon-gamma receptors, and functions as a soluble homolog which can bind and inhibit the biological activities of rabbit interferon-gamma (Upton, C., Mossman, K., and McFadden, G. (1992) Science 258:1369-1372). M-T7, the most abundantly secreted protein from myxoma virus-infected cells, was shown to be expressed in significant biological amounts as a typical poxvirus early gene product, efficiently secreted at early times of infection to levels that exceed 5 x 10(7) molecules/cell, and function as a stable inhibitory protein in infected cell supernatants until late times of infection. M-T7 was specific in binding and inhibiting rabbit interferon-gamma, and did not bind either human or murine interferon-gamma. Scatchard analysis of rabbit interferon-gamma binding curves yielded a single high affinity binding site on M-T7, with a Kd of 1.2 x 10(-9) M, which is comparable to the affinity between soluble forms of cellular interferon-gamma receptors and their cognate ligands. In comparison, rabbit interferon-gamma was shown to bind its cellular receptor with a Kd of 5.9 x 10(-10) M, again comparable to the affinity of membrane bound forms of other mammalian interferon-gamma receptors for interferon-gamma. Thus, the myxoma virus M-T7 protein is a functional soluble interferon-gamma receptor homolog which binds and inhibits interferon-gamma with high affinity in a species-specific manner.

Amino Acid Sequence↗