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PubMed1975

Cyclic AMP potentiation of interferon antiviral activity and effect of interferon on cellular cyclic AMP levels.

Treatment of L cells with 3 to 10 mM 3':5'-cyclic adenosine monophosphate (cAMP) in the presence of interferon was found to potentiate the development of antiviral activity. The dose response of interferon activity at various time periods in the presence and absence of cAMP indicated that potentiation of interferon activity by cAMP occurred at an early stage in the development of antiviral activity. Among the analogues of cAMP tested for interferon-potentiating activity, only the acylated derivatives were found to be active. Combined L-epinephrine and theophylline treatment of cells elevated cellular cAMP levels and also potentiated interferon-mediated antiviral activity. Interferon was also found to elevate cAMP levels in L cells. This activity was limited to biologically active interferon and antagonized the depression of cAMP associated with vesicular stomatitis virus (VSV) infection of L cells. These observations suggest that some aspects of interferon's biological activity is associated with an alteration in cellular levels of cAMP.

Animals↗
PubMed1980

Interferon induction by viruses. IV. Sindbis virus: early passage defective-interfering particles induce interferon.

We have shown that a single defective-interfering (DI) particle of early (5th) passage Sindbis virus induces maximal amounts of interferon in an 'aged' primary chick embryo cell. The capacity of such DI particles to induce interferon is inactivated by small amounts of u.v. radiation (i/e dose = 232 ergs/mm2). The I/e dose for inactivation of the interferon-inducing capacity of infectious virus particles is 399 ergs/mm2 and for infectivity is 101 ergs/mm2. Pre-treatment with interferon blocks formation of interferon in response to either DI or infectious virus particles. Our results suggest that Sindbis virus genes must be expressed to form the interferon inducer, which is presumably a molecule of double-stranded (ds)RNA. We postulate that for interferon induction, the genomic RNA which codes for genes G and A must be translated into products whose concerted action produces a dsRNA molecule upon synthesis of a segment of RNA complementary to the genome. The RNA from early passage DI particles is sufficiently large (25S, 1.6 x 10(6) mol. wt.) to accommodate these genes, whereas the RNA from the late passage DI particles (20S, 1.0 x 10(6) mol. wt.) is not. Late (15th) passage DI particles do not induce interferon formation.

Animals↗
PubMed1979

Interferon and cytotoxic factor (cytotoxin) released in the blood of mice infected with Mycobacterium bovis BCG. I. Enhanced production of interferon and appearance of cytotoxin stimulated by capsular polysaccharide of Klebsiella pneumoniae or bacterial lipopolysaccharide.

Interferon production stimulated by the active substance (neutral fraction) of the capsular polysaccharide of Klebsiella pneumoniae (neutral CPS-K) in BCG-infected mice was compared with that by bacterial lipopolysaccharide (LPS). Prior infection with BCG increased the responsiveness of mice to the lethal effect of neutral CPS-K as well as to that of LPS. Associated with this, BCG-infected mice showed a markedly enhanced ability to produce interferon after stimulation not only by LPS but also by neutral CPS-K. In addition, a cytotoxic factor (cytotoxin) was found to be released in the serum of BCG-infected mice after injection of these inducers. The kinetics of production of interferon and cytotoxin stimulated by neutral CPS-K were very similar to those stimulated by LPS. The time pattern of cytotoxin production was not in parallel with that of interferon production. Interferon reached a peak 2 hr and cytotoxin 3 hr after injection with these inducers. Interferon and cytotoxin produced by neutral CPS-K showed essentially the same stabilities to heating at 56 C and to treatment at pH 2 respectively as those produced by LPS. Interferon was inactivated by heating at 56 C more rapidly than cytotoxin. Cytotoxin was inactivated by treatment at pH 2 for 24 hr, whereas interferon activity was well preserved after this treatment. These results suggest that both activities are the result of different substances.

Animals↗
PubMed1989

The potential role of interferons and interferon antagonists in inflammatory disease.

Studies indicate that, among a number of other cytokines, interferons (IFN alpha, beta and gamma) are important elements regulating acute as well as chronic inflammatory responses. The role of interferons has been investigated in various experimental models of inflammation, by administration both of interferons and of antibodies that block the biological activity of interferons formed endogenously. The conclusions reached from these experiments clearly indicate that interferons can boost as well as inhibit inflammation. The effects depend on the type of inflammation studied, the time of interferon administration or emergence in the tissue, the type of interferon (alpha/beta or gamma), the dosage, and the presence of other inflammation-controlling cytokines. The effect of blockage of IFN gamma by the systemic administration of neutralising antibodies is particularly clear. Such blockage has been found to profoundly modify local lipopolysaccharide (LPS)-induced inflammation, brain inflammation due to autoimmunity or infection, and shock reactions caused by systemic administration of LPS. Further research on the particular place occupied by interferons in the inflammation-controlling cytokine network holds great promise, not only for better understanding but also for improved therapy of acute and chronic inflammatory disease.

Animals↗
PubMed1999

Interferon therapy reduces the risk for hepatocellular carcinoma: national surveillance program of cirrhotic and noncirrhotic patients with chronic hepatitis C in Japan. IHIT Study Group. Inhibition of Hepatocarcinogenesis by Interferon Therapy.

BACKGROUND: Previous studies on the effect of interferon therapy on the incidence of hepatocellular carcinoma have not sufficiently assessed degree of liver fibrosis, a major risk factor for hepatocellular carcinoma. OBJECTIVE: To evaluate the effect of interferon therapy on incidence of hepatocellular carcinoma, adjusting for risk factors, including the degree of liver fibrosis. DESIGN: Retrospective cohort study. SETTING: Seven university hospitals and one regional core hospital in Japan. PATIENTS: 2890 patients with chronic hepatitis C who had undergone liver biopsy since 1986. Of these patients, 2400 received interferon and 490 were untreated. MEASUREMENTS: The degree of liver fibrosis was assessed from stage F0 (no fibrosis) to stage F4 (cirrhosis). Response to interferon was determined virologically and biochemically. Screening for development of hepatocellular carcinoma was performed periodically during an average follow-up of 4.3 years. Effect of interferon therapy on the risk for hepatocellular carcinoma was analyzed by using Cox proportional hazards regression. RESULTS: Hepatocellular carcinoma developed in 89 interferon-treated patients and in 59 untreated patients. Among untreated patients, the annual incidence of hepatocellular carcinoma increased with the degree of liver fibrosis, from 0.5% among patients with stage F0 or F1 fibrosis to 7.9% among patients with stage F4 fibrosis. The cumulative incidence in treated and untreated patients differed significantly for patients with stage F2 fibrosis (P = 0.0128) and for those with stage F3 fibrosis (P = 0.0011). In multivariate analysis, interferon therapy was associated with a reduced risk for hepatocellular carcinoma (adjusted risk ratio, 0.516 [95% CI, 0.358 to 0.742]; P < 0.001), especially among patients with sustained virologic response (risk ratio, 0.197 [CI, 0.099 to 0.392]), among those with persistently normal serum alanine aminotransferase levels (risk ratio, 0.197 [CI, 0.104 to 0.375]), and among those with alanine aminotransferase levels less than two times the upper limit of normal (risk ratio, 0.358 [CI, 0.206 to 0.622]). CONCLUSIONS: Interferon therapy significantly reducesthe risk for hepatocellular carcinoma, especially among virologic or biochemical responders.

Alanine Transaminase↗
PubMedDate not supplied

Effectiveness of leukocyte interferon in patients affected by HCV-positive mixed cryoglobulinemia resistant to recombinant alpha-interferon.

OBJECTIVE: Interferon is the first-choice therapy for HCV-positive mixed cryoglobulinemia, but only a small fraction of the patients show long-term recovery from the disease. In non-responders or relapsers, the second-line therapy (high dose interferon) generally is not effective. The aim of this study was to evaluate the effectiveness of leukocyte interferon as a second-line therapy in patients who are non-responders or relapsers to a first course of recombinant interferon. METHODS: Twenty-eight patients with HCV-positive mixed cryoglobulinemia were enrolled. In each case the HCV-RNA and HCV genotype, as well as the usual laboratory parameters, were determined before, at the end of therapy and 1 year after the end of therapy. All patients were treated following the same schedule: leukocyte interferon 3,000,000 three times a week for one year. RESULTS: Only 5 patients obtained complete recovery from viral infection as well as from all signs and symptoms of the disease. Most patients (80%) experienced relief from clinical symptoms without recovery from HCV replication. Responders to the second interferon course were "relapsers" to the first treatment. No patient considered as a "non-responder" showed complete remission from the disease after the second treatment. CONCLUSIONS: A second leukocyte interferon course could be useful for patients affected by mixed crvoglobulinemia who relapsed after a first course of recombinant interferon therapy.

Adult↗
PubMedDate not supplied

Interferon-alpha suppresses leptin levels: studies in interferon-alpha treated patients with hepatitis C virus infection and murine adipocytes.

Leptin is an adipocyte-derived protein, which signals the status of current energy stores and energy intake to the central nervous system. Interferon-alpha therapy is frequently associated with loss of appetite and weight reduction. In this study, we tested whether interferon-alpha is able to regulate leptin synthesis. We therefore determined leptin plasma concentrations in thirteen patients with chronic hepatitis C who were treated with 1 x 10(7) IU interferon-alpha daily, up to 21 days after initial treatment. Furthermore, leptin concentrations and messenger RNA levels were quantified in interferon-alpha-treated and untreated murine adipocytes. After reaching peak plasma levels at 12 hours, probably reflecting the circadian rhythm, leptin concentrations fell and were significantly lower after 14 days. They remained significantly decreased 17 and 21 days after the start of the interferon-alpha treatment. In murine adipocytes exposed to interferon-alpha, leptin secretion was significantly decreased while messenger RNA levels remained unchanged. Our data suggest that, in contrast to proinflammatory cytokines such as interleukin-1, interferon-alpha suppresses leptin secretion in adipose tissue. We therefore hypothesize that loss of weight and appetite in interferon-alpha-treated patients with chronic hepatitis C might not be due to an elevation of leptin resulting in signals of increased energy stores in the brain.

3T3 Cells↗
PubMed1991

[Autoantibodies related to interferon therapy in chronic hepatitis B may affect the therapeutic response to interferon].

We have evaluated the problem of autoantibodies such as antinuclear antibodies (ANA), smooth muscle antibody (SMA) and antibodies to thyroid microsomal (TMA) and to thyroglobulin (TGA) related to interferon therapy in 27 patients with chronic hepatitis B. Anti-interferon antibody was also studied by Western blot method. Eight patients had ANA and 2 had SMA during interferon therapy. However, 6 of the 8 patients were ANA positive and one of the 2 was SMA positive prior to interferon treatment. No patients developed TMA, TGA or anti-interferon antibody. Eight (29.6%) of the 27 patients had clearance of both DNA polymerase and HBeAg and persistent normalization in alanine aminotransferase levels with interferon therapy. Seven of the 8 responders developed none of the autoantibodies related to interferon therapy. These results suggest that the presence of ANA or SMA during treatment may affect the therapeutic response to interferon.

Adolescent↗
PubMed1986

Characterization of human interferon species using gel extraction and monoclonal antibodies: implications on clinical use of interferon preparations.

Human interferons from various sources have been characterized using sodium dodecyl sulfate polyacrylamide gel electrophoresis followed by electrotransfer onto nitrocellulose and reaction with specific polyclonal and monoclonal antibodies. When gel slices were extracted, alpha-interferon subspecies possessed antiviral activity predominantly in the 18.6-19.7K region bands, the beta-interferon in the 22.1K band, and gamma-interferon in the 16.5-18.0K bands. Three of the monoclonal antibodies (Ab 138, Ab 126, Ab 098) reacted with a characteristic triplet of biologically active bands (18.6K, 19.1K, 19.7K) obtained using the Namalwa cell interferons, while two (Ab 194 and Ab 232) reacted only with the 18.6K band and Ab 523 reacted with the 19.7K band. With the human leukocyte interferons, Ab 098, Ab 194, and Ab 232 reacted with the active 18.6K band. The Ab 138, Ab 126, and Ab 523 reacted specifically with certain lower molecular weight active bands (13K region). A comparison of the antiviral activity and reactivity towards monoclonal and polyclonal antibodies presents a differentiation of the subspecies of interferons in the wide array of closely related proteins in interferon preparations packaged for clinical use.

Antibodies, Monoclonal↗
PubMed1986

Interferons: from molecular biology to man. Part 1. Genetics and molecular biology of the interferon system.

In 1986, 29 years after the original papers on 'the interferon', Alick Isaacs' optimism and enthusiasm for this discovery has been more than justified and the scope of interferon research ranges from genetics and molecular biology to clinical trials in man. In this series of three articles I hope to explain the importance of interferons to these, and other, areas of science. Part 1 describes the genetics of the interferon system, how the genes are controlled, and the properties of their products. It will also outline some of the molecular changes that occur in the cell after the interaction of interferons with a specific cell-surface receptor. Part 2 describes how the interferon-induced changes in cellular RNA and protein synthesis can cause profound changes in cell behaviour, and Part 3 relates such functional changes in the cell to the interferon system in the whole animal and discusses the therapeutic potential of interferons given as antiviral or anticancer therapy.

Animals↗
PubMed1986

Immunologic effects of interferon-alpha in man: treatment with human recombinant interferon-alpha suppresses in vitro immunoglobulin production in patients with chronic type B hepatitis.

The effect of human recombinant interferon-alpha on lymphocyte proliferation and differentiation was studied in 18 patients with chronic type B hepatitis who were participating in a randomized controlled trial of interferon-alpha therapy. Peripheral blood mononuclear cells (PBMC) were obtained by lymphopheresis before and during a 4 mo course of interferon. Pokeweed mitogen-induced immunoglobulin synthesis by PBMC obtained from patients before therapy was similar to that of PBMC from normal individuals. However, after 2 wk treatment with human recombinant interferon-alpha mitogen-induced immunoglobulin production was decreased by an average of 50%. Staining for cytoplasmic immunoglobulin revealed decreases that paralleled secreted immunoglobulin, indicating that interferon-alpha treatment inhibited immunoglobulin synthesis. Mixing autologous T and B cell enriched populations from before and during interferon treatment revealed that the decrease in immunoglobulin synthesis involved a defect in the B cell-enriched population. In contrast to immunoglobulin synthesis, pokeweed mitogen-induced lymphocyte proliferation was not significantly affected by in vivo administration of interferon-alpha. Thus a major effect of in vivo interferon-alpha on immunoregulation in patients with chronic type B hepatitis appears to be an inhibition of the late stages of B cell differentiation into immunoglobulin producing and secreting plasma cells.

Antibody Formation↗
PubMedDate not supplied

[Ability of influenza virus strains to induce interferon and their sensitivity to the action of exogenous interferon].

Investigation of 112 influenza A (H1N1 and H3N2) virus strains isolated in different years demonstrated their different interferon-inducing activity. The detection of strain differences in the process of interferon production is very important for the study of influenza infection pathogenicity. Of special importance are the studies of influenza virus strain sensitivity to the effect of exogenous interferon. Overcoming of resistance to interferon is important for effective influenza control. The experiments done by the authors confirm that interferon is a factor of natural immunity. When exogenous interferon is given to an infected host, it interacts with interferon induced by the infectious process. The therapeutic-prophylactic effect of interferon was clearly manifest with increasing age.

Age Factors↗
PubMed1983

Direct action of interferon and inducers of interferon on tumor cells in athymic nude mice.

Two interferon-mediated enzyme activities, the protein kinase and pppA (2'p5'A)n synthetase (2-5A synthetase) were used to assess the presence and action of interferon on HeLa tumor cells in athymic nude mice. The protein kinase is manifested by the phosphorylation of endogenous proteins with a molecular weight of 67,000 and 72,000 in mouse and human cells, respectively. Treatment of HeLa tumor-bearing mice with mouse interferon (alpha and beta) resulted in enhanced levels of 2-5A synthetase and protein kinase (Mr 67,000) activities in the spleen and lung while there were no apparent effects on HeLa cells. In these HeLa tumor cells of human origin, the 2-5A synthetase and protein kinase (Mr 72,000) activities were enhanced considerably only after treatment of mice with human fibroblastic (beta) interferon. When HeLa tumor-bearing mice were given injections of polyadenylate-polyuridylate or with polyinosinylate-polycytidylate, then the 2-5A synthetase and the protein kinase activities were enhanced in tumor cells [protein kinase] as well as in the different tissues [protein (Mr 67,000) kinase] of mice since both mouse and human interferons were produced under these conditions. These results indicate a direct action of interferon on homologous tumor cells, and furthermore they indicate that tumor cells in an organism may themselves produce interferon and respond to their own interferon.

2',5'-Oligoadenylate Synthetase↗
PubMed1978

Glycosylation of interferons. Effects of tunicamycin on human immune interferon.

Human immune interferon, induced in leukocytes by phytohemagglutinin, was prepared in the absence and presence of tunicamycin, an antibiotic which selectively inhibits the glycosylation of newly synthesized glycoproteins. Interferon preparations, produced in the absence of the antibiotic, displayed a considerable chromatographic heterogeneity on: (a) concanavalin A-agarose, (b) phenyl-agarose, (c) Cibacron Blue F3GA-agarose, and (d) polyuridylic acid-agarose. This heterogeneity was completely eliminated when tunicamycin (2 microgram/ml) was present during induction of interferon; all activity was then recovered in the breakthrough fractions from all sorbents. The level of interferon activity in leukocyte culture fluid was not affected by tunicamycin within the range of concentration 0.05 to 2.0 microgram/ml. These data indicate that (a) human immune interferon undergoes glycosylation, and tunicamycin is an effective inhibitor of this process. Thus, it appears that (b) at least some of the carbohydrates of human immune interferon are N-glycosidically linked. Moreover, it seems that (c) glycosylation is not necessary for an interferon molecule to either be secreted by the cell or (d) to express its antiviral function. Such properties of human immune interferon as (e) the apparent hydrophobicity and (f) an affinity for a polyribonucleotide are conferred only when its glycosylation is unimpaired.

Glucosamine↗
PubMed1997

Effect of iron depletion on long-term response to interferon-alpha in patients with chronic hepatitis C who previously did not respond to interferon therapy.

About half of patients with chronic hepatitis C treated with interferon will not have a biochemical or virological response. Several studies suggested that increased hepatic iron content may negatively influence the response to interferon. We conducted this prospective trial to evaluate the effect of iron depletion on the response to a repeat course of interferon in 20 chronic hepatitis C patients who previously had not responded to interferon. The patients underwent 500-ml phlebotomies every 2 weeks until iron deficiency was achieved. Patients were then started on a 6-month course of interferon alfa-2b (3 million units, t.i.w.). These patients required a mean of 6.0 (range, 1-14) phlebotomies to become iron deficient. ALT levels decreased in 18 of 20 patients and became normal in 4 patients. Mean ALT levels decreased from 154.2 to 87.9 U/L (p = 0.0006). At the end of 24 wk of interferon therapy, ALT levels were normal in 11 patients, 3 of whom had undetectable HCV RNA in the serum. One additional patient with abnormal ALT had undetectable HCV RNA. After 6 months of follow-up, one of the HCV RNA negative patients relapsed with reappearance of HCV RNA and elevation of ALT. In summary, 15% of chronic hepatitis C patients who previously failed interferon now had a sustained response to interferon therapy that was preceded by iron depletion.

Adult↗
PubMed1991

A phase II study alternating alpha-2a-interferon and gamma-interferon therapy in patients with chronic myelogenous leukemia.

Patients with Philadelphia chromosome-positive chronic myelogenous leukemia (CML) were treated with a combination of alpha-interferon and gamma-interferon. Recombinant alpha-2a-interferon (Roferon-A, Hoffmann-LaRoche, Inc., Nutley, NJ) and recombinant gamma-interferon (Genentech, Inc., South San Francisco, CA) were administered on alternating weeks each at doses ranging from 2 to 10 MU/m2 given intramuscularly. Of the 27 patients, 11 (41%) achieved complete hematologic remission (CHR) and 3 (11%) achieved partial hematologic remission (PHR). Responses were seen among 9 of 22 (41%) patients treated during the chronic phase of the disease and in 2 of 5 (40%) patients treated during the accelerated phase/second chronic phase. Cytogenetic responses were seen in six patients, including one complete response and five minor responses. Toxicities included flu-like symptoms, which appeared to be more severe with gamma-interferon than with alpha-interferon, hypertriglyceridemia, and thrombocytopenia. In this limited study, an improved outcome was not observed for the combination regimen compared with alpha-interferon alone.

Adolescent↗
PubMed2002

Mycophenolate mofetil in combination with recombinant interferon alfa-2a in interferon-nonresponder patients with chronic hepatitis C.

BACKGROUND/AIMS: Since ribavirin was able to improve the antiviral efficacy of interferon alfa in patients with chronic hepatitis C, several other adjuncts have been studied. It has been shown that mycophenolate mofetil (MMF) is a more potent inhibitor of the inosine 5'-monophosphate-dehydrogenase (IMPDH) than ribavirin. The present study is a pilot study evaluating the efficacy and safety of combination therapy with interferon alfa-2a and MMF in interferon alfa nonresponder patients. METHODS: Thirty-eight adult patients with chronic hepatitis C who did not respond to a previous interferon alfa monotherapy were enrolled to receive 6 million units of interferon alfa-2a tiw in combination with MMF (1 week 500 mg/day, 1 week 1000 mg/day, 22 weeks 2000 mg/day). RESULTS: An interim analysis of 29 patients after 12 weeks of therapy showed that only one patient had negative hepatitis C virus-RNA at this time point. There was no significant reduction of the viral load during therapy. Due to inefficacy the study was discontinued. CONCLUSIONS: Combination therapy of interferon alfa-2a and MMF is ineffective in improving virological response rates in nonresponder patients with chronic hepatitis C. These data suggest that inhibition of the IMPDH seems not to be the major mechanism of ribavirin in enhancing the antiviral effect of interferon alfa in chronic hepatitis C.

Adult↗
PubMed1989

[Interferon-specific cellular receptors in cultured human cells, differing in sensitivity to alpha-interferon].

The interferon-specific cellular receptors in human cells cultures differing in sensitivity to alpha-interferon have been studied. The J-41 cells resistant to alpha-interferon are practically devoid of receptors highly specific to alpha-interferon. The coefficient of equilibrium and the number of receptors analyzed after Scatchard for J-96 culture of cells are 15.6 x 10(11) M-1 and 210 +/- 90, respectively. Evidently, resistance of J-41 cells to alpha-interferon is connected with the absence of interferon receptors and, as a consequence, inability to interferon-receptor interaction.

Cells, Cultured↗