Increased efficacy of human natural interferon alpha (IFN-alpha n3) versus human recombinant IFN-alpha 2 for inhibition of HIV-1 replication in primary human monocytes

Protection from pulmonary tissue damage associated with infection of cynomolgus macaques by highly pathogenic avian influenza virus (H5N1) by low dose natural human IFN-α administered to the buccal mucosa

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Highly pathogenic avian influenza viruses cause extensive pulmonary damage.

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A low dose oral formulation of natural human interferon-α (Alferon LDO) inhibits H5N1 induced pulmonary damage.

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All fatal human cases of H5N1 exhibit Acute Respiratory Disease Syndrome (ARDS).

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Emerging highly pathogenic avian influenza viruses (H5N1, H7N9, and others) are a major pandemic threat.

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Similar results have been observed with type-1 IFN amelioration of pulmonary damage with SARS-CoV.

Using an established nonhuman primate model for H5N1 highly pathogenic influenza virus infection in humans, we have been able to demonstrate the prophylactic mitigation of the pulmonary damage characteristic of human fatal cases from primary influenza virus pneumonia with a low dose oral formulation of a commercially available parenteral natural human interferon alpha (Alferon N Injection®). At the highest oral dose (62.5 IU/kg body weight) used there was a marked reduction in the alveolar inflammatory response with minor evidence of alveolar and interstitial edema in contrast to the hemorrhage and inflammatory response observed in the alveoli of control animals. The mitigation of severe damage to the lower pulmonary airway was observed without a parallel reduction in viral titers. Clinical trial data will be necessary to establish its prophylactic human efficacy for highly pathogenic influenza viruses.

[The role and possibilities of natural interferon treatment in chronic hepatitis C: experience with natural interferon treatment for patients barred from combined antiviral therapy because of the STOP rule]

The first choice, and the most efficient therapy for chronic hepatitis C is the pegylated interferon + ribavirin treatment. The introduction and application of the STOP rule (pegylated interferon + ribavirin treatment should be stopped in cases without sufficient virological answer for the therapy at the 12th or 24th week of the treatment) is motivated by the very high cost of this treatment.

AIMS

The greatest problem of the application of the STOP rule is that these patients are not coming in for the proven advantages of one-year interferon treatment (arrest or decrease the inflammation, decrease or prevent the progression to liver cirrhosis, decrease probability or prevent the development of hepatocellular carcinoma), which were observed almost in virologically slow-, partial-, or non-responder patients who received one-year interferon therapy. Based on these data, the official Hungarian treatment protocol allows and recommends the continuation of the antiviral treatment by natural interferon for patients whose pegylated interferon + ribavirin treatment should have been stopped because of the STOP rule.

PATIENTS AND METHODS

15 patients whose pegylated interferon + ribavirin treatment should have been stopped because of the STOP rule (8 men, 7 women, age: 35-63, mean: 48.8 years, HCV genotype: 1b, HAI mean: 6.7, SD: +/-5.03; stage: mean: 1.75 SD: +/-0.9) treatment was continued with natural IFN for further 16-36 (mean 23.7) weeks. The total treatment duration was 48-52 weeks. The duration of follow-up was at least 6 months.

CONTROL GROUP

18 patients whose pegylated interferon + ribavirin treatment should have been stopped because of the STOP rule (7 men, 11 women, age: 32-63, mean: 48.7 years, HCV genotype: 1b, HAI mean: 10.1, SD: +/-4.8; stage mean: 2.0 SD: +/-0.6). The duration of follow-up was at least 6 months.

RESULTS

There is no significant difference between the two groups. The ALT level significantly decreased (73.4 U/l SD: +/-25.5 versus 45.9 U/l SD: +/- 22.1) due to pegylated interferon + ribavirin treatment, and remained at this level during the natural interferon treatment and the follow up (45.7 U/l SD: +/-15.1, and 49.3 U/l SD: +/-19.4 U/l; p < 0.001). The difference is significant. The ALT level decreased (108.5 U/l SD: +/-69.8 versus 86.0 U/l SD: +/-82.8) due to pegylated interferon + ribavirin treatment, but increased after the cessation of the therapy (99.7 U/l SD: +/-60.9) in the control group. The biochemical response (significant reduction of ALT level) which was detected during the pegylated interferon + ribavirin treatment remained permanent during the continuation and after the cessation of the therapy in the natural interferon treated group, while relapse occurred in every case in the control group. The viral load increased at least 1 log 10 after cessation of the therapy in pegylated interferon + ribavirin treatment non-responder patients. The natural interferon treatment was able to control the viral replication (prevent the increasing of the viral load), but after the termination of natural interferon dosage, similar elevation of viral load was observed. The subjective side effects of natural interferon treatment were rarely and milder. Leucopenia and thrombopenia occurs rarely and was milder than that during the pegylated interferon + ribavirin therapy.

CONCLUSIONS

The patients have no difficulty in the application of natural interferon; probably the positive psychic effect of the fact that they have not been barred from treatment compensated the technical hardness (three injections weekly). A wide range of the application of this therapeutic possibility, and further studies with larger number of patients are suggested.

In vitro susceptibility of 10 clinical isolates of SARS coronavirus to selected antiviral compounds

Effective antiviral agents are urgently needed to combat the possible return of severe acute respiratory syndrome (SARS). Commercial antiviral agents and pure chemical compounds extracted from traditional Chinese medicinal herbs were screened against 10 clinical isolates of SARS coronavirus by neutralisation tests with confirmation by plaque reduction assays. Interferon-beta-1a, leukocytic interferon-alpha, ribavirin, lopinavir, rimantadine, baicalin and glycyrrhizin showed antiviral activity. The two interferons were only active if the cell lines were pre-incubated with the drugs 16 h before viral inoculation. Results were confirmed by plaque reduction assays. Antiviral activity varied with the use of different cell lines. Checkerboard assays for synergy were performed showing combinations of interferon beta-1a or leukocytic interferon-alpha with ribavirin are synergistic. Since the clinical and toxicity profiles of these agents are well known, they should be considered either singly or in combination for prophylaxis or treatment of SARS in randomised placebo controlled trials in future epidemics.

Structure of the mitochondrial ATP synthase by electron cryomicroscopy

We have determined the structure of intact ATP synthase from bovine heart mitochondria by electron cryomicroscopy of single particles. Docking of an atomic model of the F1-c10 subcomplex into a major segment of the map has allowed the 32 A resolution density to be interpreted as the F1-ATPase, a central and a peripheral stalk and an FO membrane region that is composed of two domains. One domain of FO corresponds to the ring of c-subunits, and the other probably contains the a-subunit, the transmembrane portion of the b-subunit and the remaining integral membrane proteins of FO. The peripheral stalk wraps around the molecule and connects the apex of F1 to the second domain of FO. The interaction of the peripheral stalk with F1-c10 implies that it binds to a non-catalytic alpha-beta interface in F1 and its inclination where it is not attached to F1 suggests that it has a flexible region that can serve as a stator during both ATP synthesis and ATP hydrolysis.

It is hazardous to treat HIV patients with interferon-alpha

Interferon-alpha is shown to play a key role in the progressing immunodysfunction that characterizes HIV infection. In particular, interferon-alpha is responsible for the development of an autoimmune state that is prone to serious complications. Therefore, treatment of HIV patients with IFN-alpha is hazardous. There are results suggesting that anti-interferon-alpha immunization might be a method for prophylaxis and treatment of the autoimmune state in HIV patients. This treatment may prevent complications of HIV infection and the transition to AIDS.

Modulation of cytokine-induced HIV gene expression by competitive binding of transcription factors to the coactivator p300

The host response to viral infection involves the secretion of multiple cytokines which alter immune function and viral replication. These proteins activate several signal transduction pathways in infected cells which must be integrated to regulate cellular and viral gene expression. In this report, we demonstrate that specific transcription factors induced by distinct cytokines regulate HIV transcription by competitive binding to the p300 coactivator. Interferon-alpha (IFN-alpha) was found to inhibit NF-kappaB-dependent HIV gene expression stimulated by tumor necrosis factor-alpha (TNF-alpha). This inhibition was mediated by binding of the IFN-alpha signal transducer and activator of transcription 2, Stat2, to a specific domain of p300 which also binds to the RelA (p65) subunit of NF-kappaB. p300 was found to be limiting with respect to RelA (p65) and Stat2, and this effect was reversed by overexpression of p300. Inhibition by Stat2 was specific for NF-kappaB and was not mediated by Stat1, which is also induced by IFN-alpha. Gene activation induced by the Stat2 transcription domain was also inhibited by expression of RelA. These results demonstrate that HIV transcription can be regulated in the nucleus by competitive binding of specific cytokine-induced transcription factors to a discrete domain of a transcriptional coactivator.

Different relative activities of human cell-derived interferon-alpha subtypes: IFN-alpha 8 has very high antiviral potency

Interferon-alpha (IFN-alpha) subtypes were separated by HPLC from the IFN mixtures produced by virus-stimulated human lymphoblastoid cells and leukocytes. Together with preparations of lymphoblastoid IFN and recombinant IFN-beta, these were tested in three human tumor cell lines derived from liver, lung, and neuroblasts. Their relative antiviral activities differed markedly: subtype IFN-alpha 8 was the most potent and IFN-alpha 1 the least. The results were broadly similar in all three cells, with some minor differences. when the same preparations were tested for inhibition of thymidine incorporation, the relative activities were quite different: subtypes IFN-alpha 10, IFN-alpha 17, IFN-alpha 21, and IFN-alpha 5 were now the most active, and IFN-alpha 2 was the least active. IFN-alpha 1 and IFN-alpha 8 had comparable intermediate activity. Thus, the differences in activity were not caused by degradation of some subtypes during their separation. IFN-alpha 8 not only had the greatest antiviral activity but also, like IFN-beta, induced an antiviral state in U1 mutant cell lines, which lack the tyrosine kinase, Tyk2, required for signal transduction by other IFN-alpha subtypes.

Effects of recombinant interferon-tau on ovine lentivirus replication

As a pregnancy recognition signal, sheep trophoblast cells secrete a type I interferon, ovine interferon-tau (OvIFN-tau), which has potent antiviral activity. We studied the effects of a recombinant protein (rOv-IFN-tau) on the replication of ovine lentivirus (OvLV) in goat synovial membrane cells. The amount of provirus DNA, as measured by polymerase chain reaction (PCR), the virus titers, and the number of OvLV-induced syncytia were 76.5%, 82%, and 95%, respectively, lower in cultures treated with rOv-IFN-tau than in placebo-treated controls (p < 0.01). rOv-IFN-tau also reduced OvLV reverse transcriptase activity and protected cells from OvLV-induced cell lysis, but the effect was less dramatic. The antiviral activity increased with the concentration up to a maximum with 256 antiviral units of rOv-IFN-tau per ml.

Characterization of beta-R1, a gene that is selectively induced by interferon beta (IFN-beta) compared with IFN-alpha

We report preliminary characterization of a gene designated beta-R1, which is selectively expressed in response to interferon beta (IFN-beta) compared with IFN-alpha. In human astrocytoma cells, beta-R1 was induced to an equivalent extent by 10 IU/mL IFN-beta or 2500 IU/mL IFN-alpha2. To address the mechanism of this differential response, we analyzed induction of the beta-R1 gene in fibrosarcoma cells and derivative mutant cells lacking components required for signaling by type I IFNs. beta-R1 was readily induced by IFN-beta in the parental 2fTGH cell line, but not by recombinant IFN-alpha2, IFN-alpha Con1, or a mixture of IFN-alpha subtypes. IFN-alpha8 induced beta-R1 weakly. beta-R1 was not induced by IFN-beta in mutant cell lines U2A, U3A, U4A, and U6A, which lack, respectively, p48, STAT1, JAK1, and STAT2. U5A cells, which lack the Ifnar 2.2 component of the IFN-alpha and -beta receptor, also failed to express beta-R1. U1A cells are partially responsive to IFN-beta and IFN-alpha8 but lacked beta-R1 expression, indicating that TYK2 protein is essential for induction of this gene. Taken together, these results suggest that the expression of beta-R1 in response to type I IFN requires IFN-stimulated gene factor 3 plus an additional component, which is more efficiently formed on induction by IFN-beta compared with IFN-alpha.