POSSIBLE MECHANISMS FOR REDUCTION OF CIRCULATING CONCENTRATIONS OF PROGESTERONE BY INTERFERON-ALPHA IN COWS - EFFECTS ON HYPERTHERMIA, LUTEAL CELLS, METABOLISM OF PROGESTERONE AND SECRETION OF LH

Experiments were performed to determine the mechanism by which recombinant bovine interferon-alpha(I)1 (rbIFN-alpha) causes an acute reduction in plasma concentrations of progesterone. In experiment 1, administration of a prostaglandin synthesis inhibitor blocked rbIFN-alpha-induced hyperthermia but did not prevent the decline in plasma concentrations of progesterone. The decline in progesterone concentrations caused by rbIFN-alpha was, therefore, not a direct consequence of the associated hyperthermia or of pathways mediated through prostaglandin synthesis. It is also unlikely that rbIFN-alpha acts to increase the clearance of progesterone since injection of rbIFN-alpha did not decrease plasma concentrations of progesterone in ovariectomized cows given an intravaginal implant of progesterone (experiment 2). In experiment 3, rbIFN-alpha did not affect basal and LH-induced release of progesterone from cultured luteal slices, indicating that rbIFN-alpha is unlikely to affect luteal function directly. Injection of rbIFN-alpha did, however, cause a decrease in plasma concentrations of LH in ovariectomized cows (experiment 4) that coincided temporally with the decrease in progesterone concentrations seen in cows having a functional corpus luteum. The present results strongly suggest that rbIFN-alpha acts to reduce secretion of progesterone by interfering with pituitary support for luteal synthesis of progesterone. The finding that rbIFN-alpha can inhibit LH secretion implies that interferon-alpha molecules should be considered among the cytokines that can regulate hypothalamic or pituitary function.

REGULATION OF BOVINE ENDOMETRIAL SECRETION OF PROSTAGLANDINS AND SYNTHESIS OF 2',5'-OLIGOADENYLATE SYNTHETASE BY INTERFERON-ALPHA MOLECULES

Experiments were performed to (1) verify the inhibitory effect of bovine trophoblast protein-1 (bTP-1) on uterine prostaglandin synthesis, (2) evaluate whether other interferon-alpha (IFN-alpha) molecules also inhibit prostaglandin secretion, and (3) test whether the enzyme 2',5'-oligoadenylate synthetase (2-5A synthetase) can be induced in endometrium by interferon-alpha. In experiment 1, all interferon molecules (bTP-1, oTP-1, bIFN-alpha and hIFN-alpha) equally inhibited secretion of PGF and PGE2 from endometrial explant cultures obtained at day 17 of the estrous cycle. In experiment 2, endometrial explants obtained from day 17 of the cycle were cultured with and without bovine serum albumin (BSA; 50-mu-g/ml) and bIFN-alpha (0, 0.84, 4.2, and 42 nM). Addition of BSA to the culture medium greatly enhanced the accumulation of PGF into the medium. The bIFN-alpha inhibited accumulation of PGF and PGE2 in both the presence or absence of BSA by 12 h. All three concentrations of bIFN-alpha were equally effective in inhibiting prostaglandin accumulation. Additionally, all concentrations of bIFN-alpha increased the amounts of 2-5A synthetase in endometrium. In conclusion, these results confirm the inhibitory effect of bTP-1 on PGF release from endometrium and demonstrate that bTP-1 can also inhibit PGE2 secretion. Furthermore, other interferon-alpha molecules, including bIFN-alpha, hIFN-alpha, and oTP-1, also reduced PGF and PGE2 secretion in culture. It is likely, therefore, that conceptus and other interferon-alpha molecules exert similar effects on endometrium in vitro and that the antiluteolytic effects of bIFN-alpha in vivo are mediated in part by changes in endometrial prostaglandin synthesis.

The effect of bovine interferon-alpha I1 on pregnancy rate in heifers.

Bovine interferon-alpha I1 (bIFN-alpha) may be useful for enhancing fertility in sheep and cattle because it has extensive sequence homology with ovine and bovine trophoblast protein-1 and, like those proteins, extends corpus luteum lifespan. To test the effectiveness of bIFN-alpha to enhance fertility, several experiments were performed in which inseminated heifers were given i.m. injections of bIFN-alpha approximately at the time of embryo-mediated signals that result in maintenance of the corpus luteum. In Exp. 1, heifers given 20 mg of bIFN-alpha daily from d 14 to 17 tended (P less than .07) to have lower pregnancy rates at d 110 to 112 of gestation (36/75; 48% vs 43/72; 60%). Similar results were obtained in Exp. 2 when heifers received a single injection of 40 mg of bIFN-alpha or placebo at d 13 after estrus; pregnancy rates at d 42 were 39/104 (38%) for bIFN-alpha and 47/98 (48%) for placebo. In Exp. 3, heifers were given gradually increasing doses of bIFN-alpha or placebo from d 11 to 19, because such a regimen had been shown to reduce the number of heifers experiencing hyperthermia after bIFN-alpha injection. Pregnancy rates were 42/95 (44%) for bIFN-alpha and 62/111 (56%) for placebo. Across all three experiments, pregnancy rates were lower (P less than .01) for heifers treated with bIFN-alpha (117/274; 43%) than for heifers treated with placebo (152/281; 54%). In conclusion, these results demonstrate that, under the administration systems used, bIFN-alpha does not increase pregnancy rate, but rather tends to reduce it.

Lack of reproductive toxicity in adult male rats exposed to interferon-alpha

Interferon-alpha (IFN- α ), a type I IFN, is a protein with antiviral, antiproliferative, and immunoregulatory activities, widely used in the treatment of several types of cancers as well as hepatitis B and C. Decrease of libido and erectile dysfunction are commonly reported by male patients during treatment of chronic hepatitis C with IFN- α . However, IFN therapy-associated underlying factors attributed to sexual dysfunction are still not well defined. Currently, there are few studies investigating the effects of IFN on male reproductive system functions. Given that, the aim of the present investigation was to examine effects of subchronic exposure to IFN- α (5 × 10(4) U/kg and 10 × 10(4) U/kg, 30 d) on serum hormones, sperm parameters, fertility, and testicular and epididymal hystopathology and morphometry in adult male Wistar rats. None of the evaluated parameters was markedly altered by IFN- α . Thus, our results suggest that exposure to IFN- α , in this experimental design, did not adversely affect sperm quality and fertile capacity of male rats.

Combined treatment with zidovudine and lymphoblast interferon-alpha in patients with HIV-related Kaposi's sarcoma

A combination of oral zidovudine (250 mg twice daily) and subcutaneous interferon-alpha (10 x 10(6) units daily) was evaluated for clinical, antiretroviral, and immunological efficacy and for side effects in 17 patients with AIDS-related Kaposi's sarcoma. Fifteen patients were evaluable. During the study period of 12 weeks, tumor responses were complete in two patients and partial in two patients (27% major response rate). Minimal responses were seen in two patients (40% overall response rate). An anti-HIV effect (reduction of serum p24 antigen by 70% or more) was observed in seven of ten evaluable patients who were initially antigenemic. CD4 lymphocyte counts remained unchanged. In six patients who had either a tumor response or a marked decline of HIV antigenemia, the treatment was continued between 12 and 59 weeks beyond the study period. Two of four patients with tumor regression at 12 weeks had an additional tumor response in this period despite prior dose reduction of interferon due to toxicity. Late progression of KS was eventually observed in four of six patients on prolonged treatment. The responsiveness of Kaposi's sarcoma seen in this study in patients with low CD4 counts and prior constitutional symptoms (fever, weight loss) was unexpected and needs further confirmation by larger patient groups. Dose-limiting toxicities were bone marrow depression (severe anemia in four and neutropenia with anemia in two patients), subjective adverse experiences (fever, fatigue, myalgia; four patients) and both (two patients).(ABSTRACT TRUNCATED AT 250 WORDS)

Influences of porcine circo-, arteriviruses and cathelicidins in plasmacytoid dendritic cell-derived interferon-alpha responses

Type I interferons (IFNs), mainly IFN-α/β play a crucial role in innate defense against viruses. In addition to their direct antiviral activity, type I IFNs have antitumoral and immunomodulatory effects. Although all cells are virtually able to induce IFN-α, the plasmacytoid dendritic cell (pDC) subset represents the ultimate producers of IFN-α as well as other proinflammatory cytokines. Due to the specific expression of TLR7 and TLR9 recognizing single-stranded (ss) RNA and unmethylated CpG motifs respectively, pDCs can secrete up to 1000 times more IFN-α than any cellular types. Additionally, it is well known that several cytokines including type I and II IFNs, Flt3-L, IL-4 and GM-CSF favor pDC-derived IFN-α responses to unmethylated CpG motifs. In a first step, we aimed to characterize and clarify the interactions of two porcine viruses with pDCs. The double-stranded DNA replicative forms of porcine circovirus type 2 (PCV2) were demonstrated to inhibit CpG-induced IFN- α by pDCs. Our study showed that none of the cytokines known to enhance pDC responsiveness can counter-regulate the PCV2-mediated inhibition of IFN-α induced by CpG, albeit IFN-γ significantly reduced the level of inhibition. Interestingly, the presence of IFN-γ enabled pDCs to induce IFN-α to low doses of PCV2. We also noted that after DNase treatment, PCV2 preparations were still able to stimulate pDCs. These data suggest that encapsulated viral ssDNA promotes the induction of IFN-α in pDCs treated with IFN-γ whereas free DNA, presumably as double-stranded forms, was responsible for inhibiting pDC responses. Regarding PRRSV, it has been reported that North American isolates did not induce and even inhibited IFN-α response in pDCs. However, PRRSV infection was also shown to lead to an induction of IFN-α in the serum and in the lungs suggesting that certain cells are responsive to the virus. Contrasting to previous reports we found that numerous PRRSV isolates directly induced IFN-α in pDCs. This response was still observed after UV-inactivation of viruses and required TLR7 signaling. The inhibition of CpG-induced IFN-α was weak and strain dependent, again contrasting with a previous report. We also observed that IFN-γ and IL-4 enhanced IFN-α response to two prototype strains, VR-2332 and LVP23. In summary, we demonstrated that both PCV2 and PRRSV promote IFN-α secretion in pDCs in vitro suggesting that IFN-α detected in PCV2- or PRRSV-infected animal might originate from pDCs. On the other hand, PRRSV replication is restricted to the macrophage (MΦ) lineage. These innate immune cells represent a heterogeneous population which can be induce to “classical” (M1) and “alternative” (M2) activated MΦ acquiring inflammatory or “wound-healing” functional properties, respectively. Nonetheless, little is known about the effect of polarization into M1 or M2 and the susceptibility of these cells to PRRSV. Thus, we examined the impact of cytokine on MΦ polarization into M1 or M2. Infections of these cells by several PRRSV isolates enabled the discrimination of PRRSV isolate in a genotype- and irulencedependent manner in M1 and IFN-β-activated MΦ. In contrast, the expression of PRRSV nucleocapsid in M2 or inactivated MΦ was indistinguishable among the PRRSV isolates tested. In the last part of my Thesis, we investigated the influence of three synthetic porcine cathelicidin peptides for their ability to deliver nucleic acid to pDCs. We reported that all cathelicidins tested can complex and quickly deliver nucleic acids resulting in IFN-α induction. Moreover, we show that the typical α- helical amphipathic conformation is required to mediate killing of bacteria but not for inducing IFN-α secretion by pDCs. Furthermore, we found that E.coli treated with one of these cathelicidins is able to induce significantly higher levels of IFN-α compared to a non-sense version of the peptide. These data suggest that cathelicidins could influence the immune response in a two-step process. First, these peptides target bacteria leading to cell lysis. In turn, cathelicidins form complexes and deliver extracellular microbial nucleic acids released into pDCs. These pDC-derived IFN-α responses could be of particular relevance in driving the adaptive immune responses against microbial infections.

Transcriptionally active Stat1 is required for the antiproliferative effects of both interferon alpha and interferon gamma.

Type I (alpha, beta) and type II (gamma) interferons (IFNs) can restrict the growth of many cell types. INF-stimulated gene transcription, a key early event in IFN response, acts through the Janus kinase-signal transducers and activators of transcription pathway, in which both IFN-alpha and IFN-gamma activate the transcription factor Stat1. A cell line lacking Stat1 (U3A) was not growth-arrested by IFN-alpha or IFN-gamma, and experiments were carried out with U3A cells permanently expressing normal or various mutant forms of Stat1 protein. Only cells in which complete Stat1 activity was available (Stat1alpha) were growth-inhibited by IFN-gamma. A mutant that supports 20-30% normal transcription did not cause growth restraint. In contrast, IFN-alpha growth restraint was imposed by cells producing Stat1beta, which lacks transcriptional activation potential. This parallels earlier results showing the truncated Stat1 can function in IFN-alpha gene activation. In addition to experiments on long-term cultured cells, we also found that wild-type primary mouse embryonic fibroblasts were inhibited by IFNs, but fibroblasts from Stat1-deficient mouse embryos were not inhibited by IFNs.

HBsAg seroclearance or seroconversion induced by peg-interferon alpha and lamivudine or adefovir combination therapy in chronic hepatitis B treatment: a meta-analysis and systematic review

Background and aims: Seroclearance or seroconversion of hepatitis B surface antigen (HBsAg) is generally considered as a clinical endpoint. The purpose of the present meta-analysis was to evaluate the effect of combined therapy with pegylated interferon alpha (PEG-IFNα) with or without lamivudine (LAM) or adefovir (ADV) on HBsAg seroclearance or seroconversion in subjects with chronic hepatitis B (CHB). Methods: Randomized controlled trials performed through May 30th 2015 in adults with CHB receiving PEG-IFNα and LAM or ADV combination therapy or monotherapy for 48-52 weeks were included. The Review Manager Software 5.2.0 was used for the meta-analysis. Results: No statistical differences in HBsAg seroclearance (9.9% vs. 7.1%, OR = 1.47, 95% CI: 0.75, 2.90; p = 0.26) or HBsAg seroconversion (4.2% vs. 3.7%, OR = 1.17, 95% CI: 0.57, 2.37; p = 0.67) rates were noticed between PEG-IFNα + LAM and PEG-IFN α + placebo during post-treatment follow-up for 24-26-weeks in subjects with hepatitis Be antigen (HBeAg)-positive CHB. No statistical differences in HBsAg clearance (10.5% vs. 6.4%, OR = 1.68, 95% CI: 0.75, 3.76; p = 0.21) were seen, but statistical differences in HBsAg seroconversion (6.3% vs. 0%, OR = 7.22, 95% CI: 1.23, 42.40; p = 0.03) were observed, between PEG-IFNα + ADV and PEG-IFNα for 48-52 weeks of treatment in subjects with HBeAg-positive CHB. A systematic evaluation showed no differences in HBsAg disappearance and seroconversion rates between PEG-IFNα + placebo and PEG-IFNα + LAM for 48-52 weeks in subjects with HBeAg-positive CHB. A systematic assessment found no differences in HBsAg disappearance and seroconversion rates between PEG-IFNα + placebo and PEG-IFNα + LAM during 24 weeks' to 3 years' follow-up after treatment in subjects with HBeAg-negative CHB. Conclusion: Combined therapy with PEG-IFNα and LAM or ADV was not superior to monotherapy with PEG-IFNα in terms of HBsAg seroclearance or seroconversion.

STARTVerso1: A Randomized Trial of Faldaprevir Plus Pegylated Interferon/Ribavirin for Chronic HCV Genotype-1 Infection

BACKGROUND & AIMS: The efficacy and tolerability of faldaprevir, a potent hepatitis C virus (HCV) NS3/4A protease inhibitor, plus peginterferon (PegIFN) and ribavirin (RBV) was assessed in a double-blind, placebo-controlled phase 3 study of treatment-naïve patients with HCV genotype-1 infection. METHODS: Patients were randomly assigned (1:2:2) to PegIFN/RBV plus: placebo (arm 1, n = 132) for 24 weeks; faldaprevir (120 mg, once daily) for 12 or 24 weeks (arm 2, n = 259); or faldaprevir (240 mg, once daily) for 12 weeks (arm 3, n = 261). In arms 2 and 3, patients with early treatment success (HCV-RNA <25 IU/ml at week 4 and undetectable at week 8) stopped all treatment at week 24. Other patients received PegIFN/RBV until week 48 unless they met futility criteria. The primary endpoint was sustained virologic response 12 weeks post-treatment (SVR12). RESULTS: SVR12 was achieved by 52%, 79%, and 80% of patients in arms 1, 2, and 3, respectively (estimated difference for arms 2 and 3 vs. arm 1: 27%, 95% confidence interval 17%-36%; and 29%, 95% confidence interval, 19%-38%, respectively; p < 0.0001 for both). Early treatment success was achieved by 87% (arm 2) and 89% (arm 3) of patients, of whom 86% and 89% achieved SVR12. Adverse event rates were similar among groups; few adverse events led to discontinuation of all regimen components. CONCLUSIONS: Faldaprevir plus PegIFN/RBV significantly increased SVR12, compared with PegIFN/RBV, in treatment-naïve patients with HCV genotype-1 infection. No differences were seen in responses of patients given faldaprevir once daily at 120 or 240 mg.

The results of a randomized trial looking at 24 weeks vs 48 weeks of treatment with peginterferon alpha-2a (40 kDa) and ribavirin combination therapy in patients with chronic hepatitis C genotype 1

Peginterferon-alpha plus ribavirin is the most effective therapy for chronic hepatitis C. This study was designed to evaluate the effect of peginterferon alpha-2a (40 kDa) plus ribavirin on sustained virological response (SVR) when administered for 24 vs 48 weeks in genotype 1 naive patients. One hundred and seventeen patients were enrolled in this controlled trial. Genotype 1 patients were randomized to 24 weeks treatment vs 48 weeks treatment. Genotype non-1 patients received 24 weeks treatment as an observational group. Outcomes were SVR (defined by hepatitis C virus-RNA-negative at week 24 of follow-up) and tolerability across the study period. The end-of-treatment response was 59% for genotype 1 (24 weeks treatment), 80% for genotype 1 (48 weeks treatment) and 92% for genotype non-1 (24 weeks treatment). The end-of-follow-up response was 19% (95% confidence interval (CI): 7.2-36.4) (genotype 1, 24 weeks) and 48% (95% CI: 30.2-66.9; P = 0.0175) (genotype 1, 48 weeks). Among genotype non-1, SVR was 76% (95% CI: 62.3-86.5). There were no unexpected adverse events.Almost half of the genotype 1 patients achieved an SVR after 48 weeks treatment with peginterferon alpha-2a (40 kDa) and low-dose ribavirin and confirmed that they should be treated for 48 weeks. Safety profile was acceptable.

Induction pegylated interferon Alfa-2a and high dose ribavirin do not increase SVR in heavy patients with HCV genotype 1 and high viral loads

Background & Aims Patients infected with hepatitis C virus (HCV) genotype 1, body weight <85 kg, and high baseline viral load respond poorly to standard doses of pegylated interferon (peginterferon) and ribavirin. We evaluated intensified therapy with peginterferon alfa-2a plus ribavirin. Methods This double-blind randomized trial included HCV genotype 1-infected outpatients from hepatology clinics with body weight <85 kg and HCV RNA titer <400,000 IU/mL. Patients were randomized to 180 μg/wk peginterferon alfa-2a for 48 weeks plus 1200 mg/day ribavirin (standard of care) (group A, n = 191) or 1400/1600 mg/day ribavirin (group B, n = 189). Additional groups included 360 μg/wk peginterferon alfa-2a for 12 weeks then 180 μg/wk peginterferon alfa-2a for 36 weeks plus 1200 mg/day ribavirin (group C, n = 382) or 1400/1600 mg/day ribavirin (group D, n = 383). Follow-up lasted 24 weeks after treatment. Results Sustained virologic response rates (HCV RNA level <15 IU/mL at end of follow-up) in groups A, B, C, and D were 38%, 43%, 44%, and 41%, respectively. There were no significant differences among the 4 groups or between pooled peginterferon alfa-2a regimens (A + B vs C + D: odds ratio [OR], 1.08; 95% confidence interval [CI], 0.831.39; P = .584) or pooled ribavirin regimens (A + C vs B + D: OR, 1.00; 95% CI, 0.791.28; P = .974). Conclusions In patients infected with HCV genotype 1 who are difficult to treat (high viral load, body weight <85 kg), a 12-week induction regimen of peginterferon alfa-2a and/or higher-dose ribavirin is not more effective than the standard regimen. © 2010 AGA Institute.

IL28B polymorphisms are markers of therapy response and are influenced by genetic ancestry in chronic hepatitis C patients from an admixed population

Background: IL28B polymorphisms are predictors of therapy response in hepatitis C virus (HCV) patients. We do not know whether they are markers of treatment response in admixed populations or not. Aims: To determine whether IL28B polymorphisms are predictors of therapy response in patients with HCV from an admixed population and are influenced by genetic ancestry. Methods: rs12979860 and rs8099917 were genotyped in 222 HCV patients treated with pegylated interferon and ribavirin. Ancestry was determined using genetic markers. Results: IL28B rs12979860 C/C was associated with sustained virological response (SVR), whereas C/T and T/T were associated with failure to therapy (P = 1.12 x 10(-5)). IL28B rs8099917 T/T was associated with SVR, and G/G and G/T were associated with nonresponse/ relapse (NR/R) (P = 8.00 x 10(-3)). Among HCV genotype 1 patients with C/C genotype, genomic ancestry did not interfere with therapy response. Among patients with rs12979860 T/T genotype, African genetic contribution was greater in the NR/R group (P = 1.51 x 10(-3)), whereas Amerindian and European genetic ancestry contribution were higher in the SVR group (P = 3.77 x 10(-3) and P = 2.16 x 10(-2) respectively). Among HCV type 1 patients with rs8099917 T/T, African genetic contribution was significantly greater in the NR/R group (P = 5.0 x 10(-3)); Amerindian and European ancestry genetic contribution were greater in the SVR group. Conclusion: IL28B rs12979860 and rs8099917 polymorphisms were predictors of therapy response in HCV genotypes 1, 2 and 3 subjects from an admixed population. Genomic ancestry did not interfere with response to therapy in patients with rs12979860 C/C, whereas it interfered in patients with C/T and T/T genotypes. Among HCV genotype 1 rs8099917 T/T patients, genomic ancestry interfered with response to therapy.