Interferon-beta treatment of human disease

Inhibitory effect of human interferon-beta-1a on activated rat and human hepatic stellate cells

BACKGROUND AND AIMS

Hepatic stellate cells (HSC) are the primary cell type mediating hepatic fibrosis. Although known for its antiviral effects, the inhibitory effects of interferon-beta (IFN-β) on HSC treatment have not yet been established.

METHODS

Both human and rat activated HSC cell lines were incubated with increasing concentrations of recombinant human IFN-β1a (rhIFN-β1a) for 24, 48 or 72 h. The effects of rhIFN-β1a on α-smooth muscle actin (α-SMA), collagen types I and III, transforming growth factor-β1 (TGF-β1), platelet-derived growth factor-BB (PDGF-BB), and mothers against decapentaplegic homolog (Smad4, Smad7) expression in HSC were examined using Western blotting and immunocytochemistry. Proliferation of HSC was evaluated via bromodeoxyuridine assay.

RESULTS

rhIFN-β1a treatment had a dose-dependent, inhibitory effect on α-SMA and collagen type I protein expression. In addition, rhIFN-β1a decreased the expression of collagen type III, TGF-β1, PDGF-BB and Smad4 protein expression in HSC compared with untreated cells. We also observed increased Smad7 protein expression and decreased proliferation in rhIFN-β1a-treated HSC.

CONCLUSIONS

Our data suggest that rhIFN-β1a treatment decreased α-SMA and collagen expression and inhibited the activation of HSC through the inhibition of the TGF-β and PDGF pathways.

Natural human interferon beta plus ribavirin combination therapy in Japanese patients infected with hepatitis C virus and a high viral load

OBJECTIVE

The aim of this pilot study was to determine the safety and efficacy of natural human interferon beta (nIFNbeta) plus ribavirin (RBV) in patients with chronic hepatitis C who did not respond to pegylated interferon alpha (PEG-IFN), with special emphasis on the incidence of mental disorders or refusal for fear of adverse effects.

METHODS

We studied 19 patients with HCV genotype 1b, 2a or 2b and a high viral load, including 8 patients with mental disorders. They were treated with nIFNbeta-RBV. Eleven patients with HCV genotype 1b of these patients were treated with nIFNbeta-RBV for 48 weeks (group A), and compared with 22 matched controls treated with PEG-IFN plus RBV for 48 weeks (group B). The other 8 patients with HCV genotype 2 were treated with nIFNbeta-RBV for 24 weeks.

RESULTS

Six of 8 patients with mental disorders and 9 of 11 patients without mental disorders completed nIFNbeta-RBV therapy; 1 patient with mental disorder dropped out due to exacerbation of depression, and 3 patients suspended the therapy due to insufficient response. The sustained virological response (SVR) was 27% (3/11) in group A and 41% (9/22) in group B (p = 0.70). During treatment, platelet count increased in group A but not in group B. SVR was 88% (7/8) in patients of genotype 2 and high viral load treated with nIFNbeta plus RBV.

CONCLUSION

nIFNbeta-RBV therapy offers sufficient safety and efficacy for patients with mental disorders, and thus could represent an excellent second-line therapy for subpopulations that are not suitable for PEG-IFN-RBV.

Bile acids for viral hepatitis

BACKGROUND

Trials have assessed bile acids for patients with viral hepatitis, but no consensus has been reached regarding their usefulness.

OBJECTIVES

To assess the beneficial and harmful effects of bile acids for viral hepatitis.

SEARCH STRATEGY

Searches were performed in The Cochrane Hepato-Biliary Group Controlled Trials Register (July 2007), The Cochrane Library (Issue 1, 2007), MEDLINE (July 2007), EMBASE (July 2007), Science Citation Index Expanded (July 2007), and Chinese Biomedical Database (July 2007).

SELECTION CRITERIA

Randomised clinical trials comparing any dose or duration of bile acids versus placebo or no intervention for viral hepatitis were included, irrespective of language, publication status, or blinding. Co-interventions were allowed in the included randomised clinical trials.

DATA COLLECTION AND ANALYSIS

Two authors extracted the data independently. The methodological quality of the trials was evaluated with respect to generation of the allocation sequence, allocation concealment, double blinding, and follow-up. The outcomes were presented as relative risks (RR) or weighted mean differences (WMD) with 95% confidence intervals (CI).

MAIN RESULTS

We identified 29 randomised trials of bile acids for hepatitis B or C; none were of high methodological quality. We were unable to extract data from two trials. In one trial, ursodeoxycholic acid (UDCA) versus placebo for acute hepatitis B significantly reduced the risk of hepatitis B surface antigen positivity at the end of treatment and serum HBV DNA level at the end of follow-up. In another trial, UDCA versus no intervention for chronic hepatitis B significantly reduced the risk of having abnormal serum transaminase activities at the end of treatment. Twenty-five trials compared bile acids (21 trials UDCA; four trials tauro-UDCA) versus placebo or no intervention with or without co-interventions for chronic hepatitis C. Bile acids did not significantly reduce the risk of having detectable serum HCV RNA (RR 0.99, 95% CI 0.91 to 1.07), cirrhosis, or portal and periportal inflammation score at the end of treatment. Bile acids significantly decreased the risk of having abnormal serum alanine aminotransferase activity at the end of treatment (RR 0.82, 95% CI 0.76 to 0.90) and follow-up (RR 0.91, 95% CI 0.85 to 0.98). Bile acids significantly increased the Knodell score (WMD 0.20, 95% CI 0.08 to 0.31) at the end of treatment. No severe adverse events were reported. We did not identify trials including patients with hepatitis A, acute hepatitis C, hepatitis D, or hepatitis E.

AUTHORS' CONCLUSIONS

Bile acids lead to a significant improvement in serum transaminase activities in hepatitis B and C but have no effects on the clearance of virus. There is insufficient evidence either to support or to refute effects on long-term outcomes including hepatocellular carcinoma, hepatic decompensation, and liver related mortality. Randomised trials with high methodological quality are required before clinical use is considered.

The role of type I interferons in TLR responses

Recent advances in unravelling the complexities of the signalling pathways that constitute innate immunity have highlighted type I interferon as a key component in the response to infection. Here we focus on the emerging field of pattern-recognition receptor signalling, specifically Toll-like receptors and retinoic acid inducible gene-like helicases, from the perspective of this 50-year-old cytokine. The type I interferon gene family encompasses more than 20 subtypes, whose nature and properties have been extensively studied during its relatively long history. In this review we update and integrate available data on the mechanics of activation of the interferon genes and the role of this cytokine family in the innate immune response.

Activities of enzymes that hydrolyze adenine nucleotides in platelets from rats experimentally demyelinated with ethidium bromide and treated with interferon-beta

The activities of the enzymes NTPDase (EC 3.6.1.5, apyrase, CD39) and 5'-nucleotidase (EC 3.1.3.5, CD73) were analyzed in platelets from rats submitted to demyelination by ethidium bromide (EB) and treated with interferon beta (IFN-beta). The following groups were studied: I - control (saline), II - (saline and IFN-beta), III - (EB) and IV - (EB and IFN-beta). After 7, 15 and 30 days, the animals (n=7) were sacrificed and the platelets were separated by the method of Lunkes et al. [Lunkes, G., Lunkes D., Morsch, V., Mazzanti, C., Morsch, A., Miron, V., Schetinger, M.R.C., 2004. NTPDase and 5'-nucleotidase in rats alloxan- induced diabetes. Diabetes Research and Clinical Practice 65, 1-6]. NTPDase activity for ATP and ADP substrates was significantly lower in groups II and III after seven days, when compared to control (p<0.001). At fifteen days, ATP hydrolysis was significantly lower in group III and IV and higher in group II (p<0.001), while there was an activation of ADP hydrolysis in group II (p<0.001), when compared with the control. 5'-nucleotidase activity was significantly higher in group IV (p<0.001) after seven days, and lower in the groups III and IV (p<0.001) after fifteen days in relation to the control. No significant differences were observed in NTPDase and 5'-nucleotidase activities after thirty days. In conclusion, our study demonstrated that the hydrolysis of adenine nucleotides is modified in platelets of rats demyelinated and treated with IFN-beta.

Is interferon-beta an alternative treatment for chronic hepatitis C

The treatment of chronic hepatitis C (CHC) is still far from optimal, particularly for those subpopulations that do not respond to the standard combination therapy with Interferon-α (IFNα) plus ribavirin. Although in some cases the use of higher doses or longer treatment periods may be effective, these approaches are generally associated with a higher incidence of adverse events, which may either lead to a reduction in patient compliance or require drug withdrawal. IFNβ could represent an interesting alternative for treating CHC patients. Controversial data about IFNβ efficacy in CHC exist, the main reason being that many results stem from pilot studies with small cohorts of patients. However, promising results have been obtained in some subgroups of patients that fail to respond to IFNα. Additionally, the good tolerability of IFNβ represents an important advantage of the drug. The rates of dropouts in controlled clinical trials, as well as the need for dose reductions or treatment discontinuation are very low. It might be worth assessing the value of IFNβ plus ribavirin in randomized studies with a larger cohort of patients, not eligible or not tolerating standard therapy, and for non-responders.

Safety of interferon β treatment for chronic HCV hepatitis

Hepatitis C is a major cause of liver-related morbidity and mortality worldwide. In fact, chronic hepatitis C is considered as one of the primary causes of chronic liver disease, cirrhosis and hepatocellular carcinoma, and is the most common reason for liver transplantation. The primary objectives for the treatment of HCV-related chronic hepatitis is to eradicate infection and prevent progression of the disease. The treatment has evolved from the use of α -interferon (IFNα) alone to the combination of IFNα plus ribavirin, with a significant improvement in the overall efficacy, and to the newer PEG-IFNs which have further increased the virological response, used either alone or in combination with ribavirin. Despite these positive results, in terms of efficacy, concerns are related to the safety and adverse events. Many patients must reduce the dose of PEG-IFN or ribavirin, others must stop the treatment and a variable percentage of subjects are not suitable owing to intolerance toward drugs. IFNβ represents a potential therapeutic alternative for the treatment of chronic viral hepatitis and in some countries it plays an important role in therapeutic protocols. Aim of the present paper was to review available data on the safety of IFNβ treatment in HCV-related chronic hepatitis.

The rates of treatment discontinuation and/or dose modification due to the appearance of severe side effects during IFNβ are generally low and in several clinical studies no requirements for treatment discontinuation and/or dose modifications have been reported. The most frequent side effects experienced during IFNβ treatment are flu-like syndromes, fever, fatigue and injection-site reactions. No differences in terms of side-effect frequency and severity between responders and non-responders have been reported. A more recent study, performed to compare IFNβ alone or in combination with ribavirin, confirmed the good safety profile of both treatments. Similar trends of adverse event frequency have been observed in subpopulations such as patients with genotype-1b HCV hepatitis unresponsive to IFNα treatment or with HCV-related cirrhosis and patients with acute viral hepatitis. If further studies will confirm the efficacy of combined IFNβ and ribavirin treatment, this regimen could represent a safe and alternative therapeutic option in selected patients.

Bile acids for viral hepatitis

BACKGROUND

The viral hepatitides are common causes of liver diseases globally. Trials have assessed bile acids for patients with viral hepatitis, but no consensus was reached regarding their usefulness.

OBJECTIVES

To assess the beneficial and harmful effects of bile acids for viral hepatitis.

SEARCH STRATEGY

Searches were performed of the trial registers of The Cochrane Hepato-Biliary Group (September 2002), The Cochrane Library (Issue 2, 2002), MEDLINE (September 2002), EMBASE (September 2002), and The Chinese Biomedical Database (April 2001).

SELECTION CRITERIA

Randomised clinical trials comparing any dose or duration of bile acids versus placebo or no intervention for viral hepatitis were included, irrespective of language, publication status, or blinding.

DATA COLLECTION AND ANALYSIS

Two reviewers extracted the data independently. The methodological quality of the trials was evaluated with respect to generation of the allocation sequence, allocation concealment, double blinding, and follow-up. The outcomes were presented as relative risks (RR) or weighted mean differences (WMD) with 95% confidence intervals (CI).

MAIN RESULTS

We identified 27 randomised trials of bile acids for hepatitis B or C; none were of high methodological quality. In one trial, ursodeoxycholic acid (UDCA) versus placebo for acute hepatitis B significantly reduced the risk of hepatitis B surface antigen positivity at the end of treatment and serum HBV DNA level at the end of follow-up. In another trial, UDCA versus no intervention for chronic hepatitis B significantly reduced the risk of having abnormal serum transaminase activities at the end of treatment. Twenty-five trials compared bile acids (21 trials UDCA; four trials tauro-UDCA) versus placebo or no intervention with or without co-interventions for chronic hepatitis C. Bile acids did not significantly reduce the risk of having detectable serum HCV RNA (RR 0.99, 95% CI 0.91 to 1.07), cirrhosis, or portal and periportal inflammation score at the end of treatment. Bile acids significantly decreased the risk of having abnormal serum alanine aminotransferase activity at the end of treatment (RR 0.82, 95% CI 0.76 to 0.90) and follow-up (RR 0.91, 95% CI 0.85 to 0.98). Bile acids significantly increased the Knodell score (WMD 0.20, 95% CI 0.08 to 0.31) at the end of treatment. No severe adverse events were reported. We did not identify trials including patients with hepatitis A, acute C, D, or E.

REVIEWER'S CONCLUSIONS

Bile acids lead to a significant improvement in serum transaminase activities in hepatitis B and C. There is insufficient evidence either to support or to refute effects on viral markers, mortality, incidence of cirrhosis, or liver histology. Trials with high methodological quality are required.

Bioprocess applications of a Sindbis virus-based temperature-inducible expression system

The production and study of toxic proteins requires inducible expression systems with low basal level expression and high inducibility. Here, we describe bioprocess applications of the pCytTS temperature-regulatable Sindbis virus replicon-based expression system. We used green fluorescent protein as a marker protein to optimize the selection of stable transfected clones with increased expression levels. Using the optimized protocol, clones were constructed that produced the growth-inhibiting, anti-viral protein interferon beta (beta-IFN). Selected clones were analyzed for temperature-dependent beta-IFN production in adherent and suspension cultures in serum free medium. Specific expression levels were around 1.0 x 10(5) IU/10(6) cells/day (0.5 microg/10(6) cells/day) in suspension cultures and over 1.5 x 10(6) IU/mL/day (7.5 microg/mL/day) in hollow fiber reactors using adherent cells. Hexahistidine-tagged beta-IFN purified from T-flask cultures was highly glycosylated and showed high specific activity. beta-IFN mRNA amplified by the viral replicase for 10 days did not show an accumulation of mutations. These data suggest the applicability of the pCytTS-inducible expression system for the production of high-quality glycoproteins in different reactors.

Mechanisms for regulation of cellular responsiveness to human IFN-beta1a

Interferons (IFNs) are potent, pleiotropic cytokines, and therefore it is likely that the cell has mechanisms to modulate IFN activity in response to excessive or prolonged IFN exposure. To investigate this question, Jurkat T cells were exposed to IFN-beta1a in vitro. The effect of dose and frequency of IFN treatment on receptor expression, the signal transduction pathway, and biologic activity was examined. Results demonstrate that at even modest doses of IFN (60 IU/ml), cell surface expression of the IFN receptor subunit, IFNAR-1, decreased significantly, and the cells were unresponsive to further IFN treatment. More interestingly, after an initial treatment with very low concentrations of IFN (<10 IU/ml), even when receptor levels remained normal and phosphorylation of signaling molecules occurred, cells were still refractory to further IFN treatment. After withdrawal of IFN, full cellular responsiveness was a progressive but surprisingly slow process. Cells retreated 2 days or 4 days after the initial IFN treatment were still refractory to even high doses (500 IU/ml) of IFN. Cells retreated 1 week after the initial IFN treatment were fully responsive. High levels of Stat1 and Stat2 correlated with the block in transcriptional activation of IFN-dependent genes and may be a mechanism by which cells can downmodulate an IFN response. Similar results were obtained when fresh peripheral blood mononuclear cells (PBMC) were treated with IFN and expression of the endogenous IFN-dependent gene, MxA, was examined. Cell surface levels of IFNAR-1 decreased and Stat1 levels increased after IFN-beta treatment, and retreatment with IFN resulted in an attenuated induction of Mx protein expression. In the context of using IFNs as therapeutic agents in the treatment of human disease, our data suggest that increasing the amount or frequency of IFN administration may not yield desired biologic effects. Thus, issues concerning the dosage and the frequency of IFN-beta administration deserve careful consideration.

Interferon induction in turkeys by oral administration of the imidazoquinolinamine S-28828 and modulation of the pathogenesis of Escherichia coli

A synthetic imidazoquinolinamine, S-28828, has been shown to be an effective antiviral and antitumor agent in mammals. This immune modifier induces a number of cytokines such as interferons, tumor necrosis factor-alpha, interleukins and granulocyte-macrophage colony-stimulating factors in mammals. We showed that when turkeys were given S-28828 orally, high serum titers of IFN were induced in a dose-dependent manner. Turkeys, once stimulated by S-28828, became refractory to IFN production by repeated stimulation. S-28828 induced spleen, bone marrow and peripheral leukocytes to produce IFN in vitro. Splenic adherent cells were the main producers of IFN after in vitro stimulation. S-28828-induced IFN was identified as type I IFN that was pH-resistant but heat-labile. We examined the effect of a high dose (100 mg kg(-1) body weight) of S-28828 on the pathogenesis of E. coli in turkeys. Treatment with S-28828 increased mortality in infected birds and impaired E. coli clearance from the liver. The enhancement of the pathogenicity of E. coli by S-28828 may have been due to the massive release of cytokines inducing a shock-like syndrome in infected turkeys.