Recombinant Human Interferon Alpha-2b Research Articles

Molecular and Biological Characterization of a Prepared Recombinant Human Interferon Alpha 2b Isoform.

Recombinant human interferon alpha2b (rhIFN-α2b) protein is FDA approved for treatment of many tumors and viral diseases. A rhIFN-α2b isoform has been produced and purified from the refolding reaction using high-resolution anion ion exchange chromatography. This isoform has a proper MW (19kDa) and high purity and homogeneity. The conservation of native linear and conformational epitopes in this isoform was immunologically confirmed by Western blot and ELISA. Mass spectrometry assessment of its intact mass showed average mass (19,337Da) equivalent to that of the expressed rhIFN-α2b protein without any chemical modification and without the first methionine. Peptide mapping of rhIFN-α2b through tryptic digestion of reductive/alkylated protein using urea as a denaturing agent gave the best pattern. The rhIFN-α2b had a high specific antiviral activity (2.5 × 108 ± 1.1 × 108IU/mg protein). In vivo clearance study of rhIFN-α2b in female SD rats (500μg/kg, intramuscularly) revealed rapid clearance (elimination half-life 0.54h with a maximum plasma concentration of 33,792pg/ml) compared with the commercial rhIFN-α2 (elimination half-life 0.75-0.96h). In conclusion, the prepared rhIFN-α2b isoform has high purity, homogeneity, native like chemical and structural composition, high antiviral activity, and proper biological stability, which reduce its immunogenicity and raise its therapeutic efficiency.

Observation of the effect of oxymatrine combined with interferon alpha-2b in the treatment of patients with chronic hepatitis B

Objective To investigate the clinical value of oxymatrine combined with interferon alpha-2b in the treatment of chronic hepatitis B. Methods From January 2014 to January 2017, Ninety patients with chronic hepatitis B in the Third People's Hospital of Linfen were divided into observation group and control group according to the random number table method, with 45 cases in each group.The control group was treated with recombinant human interferon alpha-2b, intramuscular injection of 5 million IU, 1 time/d, and on the basis of the control group, the observation group was treated with oxymatrine injection 500 mg+ 0.9% sodium chloride injection 250mL, intravenous infusion of normal saline, 1 time/d, the treatment cycle was 6 months.The changes of liver function, HBV-DNA negative rate and liver fibrosis indicators were compared between the two groups before and after treatment. Results After treatment, the liver function indicators of the observation group and the control group[ALT(45.2±8.3)IU/L, (68.4±9.5)IU/L; AST(42.6±7.2)IU/L, (63.7±9.3)IU/L]were significantly decreased, which of the observation group were significantly lower than those of the control group, the differences were statistically significant (t=11.678, 10.186, all P<0.05). The negative rate of HBV-DNA in the observation group(82.2%) was significantly higher than that in the control group(60.0%), the difference was statistically significant(χ2=5.409, P<0.05). After treatment, the levels of Ⅳ-C[(57.7±10.6)ng/L, (132.2±47.6)ng/L], LN[(103.1±33.1)ng/L, (162.5±57.9)ng/L]and HA[(158.7±59.2)ng/L, (263.4±97.9)ng/L]of the observation group and the control group were significantly decreased, which of the observation group were significantly lower than those of the control group, the differences were statistically significant (t=9.899, 5.971, 5.856, all P<0.05). Conclusion Oxymatrine injection combined with interferon alpha-2b in the treatment of chronic hepatitis B can significantly improve liver function, improve the negative rate of virus and liver fibrosis. Key words: Hepatitis B; Interferon Alfa-2b; Oxymatrine

Efficacy of nystatin vaginal effervescent tablets and nifuratel tablet combined with recombinant human interferon alpha 2b suppository in the treatment of candida vaginitis

Objective To explore the efficacy of nystatin vaginal effervescent tablets, nifuratel tablet combined with recombinant human interferon alpha 2b suppository in the treatment of candida vaginitis. Methods 124 patients with candida vaginitis were selected as the research subjects.The patients were randomly divided into two groups according to different treatment.The control group was treated with nystatin vaginal effervescent tablets + nifuratel tablet, the study group was given recombinant human interferon alpha 2b suppository on the basis of the control group.The symptoms, clinical curative effect, quality of life score, adverse reaction rate were observed and compared in the two groups. Results There were no statistically significant differences between the two groups in symptom and physical signs before treatment(all P>0.05). After treatment, the vulvar itching, burning pain, abnormal leucorrhea, redness symptoms and signs of the study group were (0.95±0.44)points, (1.02±0.51)points, (1.13±0.62)points, (1.09±0.56)points, which were significantly lower than those of the control group[(1.42±0.98)points, (1.28±1.02)points, (1.38±1.17)points, (1.37±1.12)points, t=2.529, 2.512, 2.505, 2.618, all P<0.05]. The total effective rate of the study group was 95.2%, which was significantly higher than 74.2% of the control group (Z=-2.839, P<0.05). After treatment, the quality of life scores of physiological function, bodily pain, mental health, emotional function and social function in the study group were (80.16±9.23)points, (84.22±9.95)points, (87.49±10.46)points, (89.27±12.35)points, (88.21±11.74)points, which were significantly higher than those in the control group[(67.58±5.34)points, (71.49±7.28)points, (73.52±7.61)points, (76.83±8.32)points, (75.51±8.16) points, t=9.728, 8.577, 9.036, 7.039, 7.537, all P<0.05]. The incidence rate of adverse reactions of the study group was significantly lower than that of the control group(χ2=10.978, P<0.05). Conclusion Nystatin vaginal effervescent tablets, nifuratel tablet combined with recombinant human interferon alpha 2b suppository in the treatment of candida vaginitis can significantly improve clinical symptoms, improve the therapeutic effect, and improve the quality of life of patients with significant clinical value, it is worthy of reference. Key words: Candidiasis, vulvovaginal; Nystatin; Nifuratel; Interferon alpha 2b

Response Surface Optimization of the Expression Conditions for Synthetic Human Interferon alpha-2b Gene in Escherichia coli

Recombinant human interferon alpha-2b is an FDA-approved drug for monotherapy or in combination therapy with other drugs for hepatitis and cancers. It belongs to a family of homologous proteins involved in antiviral, antiproliferative, and immunoregulatory processes. A different expression system has been used for overexpression of this protein. Escherichia coli expression system is a highly characterized host and various expression settings have been developed based on its properties. However, finding the best conditions for the overexpression of recombinant human interferon alpha-2b remains to be addressed. In this study, the expression of synthetic human interferon alpha-2b gene in E. coli was greatly improved by adjusting the expression condition. In this regard, a recombinant gene was designed and codon optimized for the periplasmic expression of this protein. Then, gene subcloning was employed to insert the synthesized gene into the pET22b expression vector. Thereafter, the response surface methodology method was employed to design 20 experiments to find out the optimum points for isopropyl β-D-1-thiogalactopyranoside concentration, post-induction period, and the cell density of induction (OD600). The expression fluctuations were assessed by using the real time polymerase chain reaction method. Our results indicated that the synthetic human interferon alpha-2b gene was successfully codon optimized and subcloned into the expression vector. The real time polymerase chain reaction results revealed that the optimum levels of the selected parameters are 0.27 mM for isopropyl β-D-1-thiogalactopyranoside concentration, 7.98 H for the post-induction period, and 3.93 for cell density (OD600). These optimized conditions led to a 3.5-fold increase in the rhIFNα2b expression, which is highly promising for large scale rhIFNα2b overexpression.

Клиническая эффективность и патогенетическое обоснование применения человеческого рекомбинантного интерферона альфа-2b в комбинированном лечении больных наружным генитальным эндометриозом

Клиническая эффективность и патогенетическое обоснование применения человеческого рекомбинантного интерферона альфа-2b в комбинированном лечении больных наружным генитальным эндометриозом

THE RATIONALE FOR ALPHA-INTERFERON IMMUNOTHERAPY IN INFANTS WITH FUNCTIONAL GASTROINTESTINAL DISORDERS AND ACUTE INVASIVE INTESTINAL INFECTION

Background: Acute intestinal infections in children are a considerable medical and social problem worldwide. Immune therapy could help to reduce the frequency of post-infectious functional intestinal dysfunction in patients with comorbidities. Aim: To evaluate the efficacy of human recombinant interferon alpha-2b, administered at acute phase of an acute invasive intestinal infection to infants in the first months of age, suffering from functional bowel disorders. Materials and methods: This was an open-label, randomized (envelope method), prospective study in two parallel groups. The study included 59 infants of the first months of life, who were breastfed, had a history of intestinal dysfunction and were hospitalized to an infectious department. We studied efficacy of recombinant interferon alpha-2b administered in rectal suppositories at a dose of chromatography with measurement of short-chain fatty acids. Results: Standard treatment was ineffective in 63.3% (95% CI 43.9–80.0%) of patients. Administration of interferon alpha-2b reduced the rate of treatment failure by day 14 to 32% (95% CI 9–56%) and the risk of persistent diarrhea for more than one month to 29% (95% CI 5–53%). In those patients who were administered interferon, inflammation at days 25 to 55 was less severe and the levels of i-forms of short-chain fatty acids were lower. Conclusion: Immunotherapy with recombinant interferon alpha-2b seems to be a promising way to improve combination treatment of acute invasive intestinal infections in infants with a history of intestinal dysfunction, as it reduces the risk of post-infectious intestinal disorders.

Improvement of in vitro stability and pharmacokinetics of hIFN-α by fusing the carboxyl-terminal peptide of hCG β-subunit

Improving in vivo half-life and in vitro stability of protein-based therapeutics is a current challenge for the biopharmaceutical industry. In particular, recombinant human interferon alpha-2b (rhIFN-α2b), which belongs to a group of cytokines extensively used for the treatment of viral diseases and cancers, shows a poor stability in solution and an extremely short plasma half-life which determines a strict therapeutic regimen comprising high and repeated doses. In this work, we have used a strategy based on the fusion of the carboxyl-terminal peptide (CTP) of human chorionic gonadotropin (hCG) β-subunit, bearing four O-linked oligosaccharide recognition sites, to each or both N- and C-terminal ends of rhIFN-α2b. Molecules containing from 5 (CTP-IFN and IFN-CTP) to 9 (CTP-IFN-CTP) O-glycosylation sites were efficiently expressed and secreted to CHO cells supernatants, and exhibited antiviral and antiproliferative bioactivities in vitro. Significant improvements in pharmacokinetics in rats were achieved through this approach, since the doubly CTP-modified IFN variant showed a 10-fold longer elimination half-life and a 19-fold decreased plasma apparent clearance compared to the wild-type cytokine. Moreover, CTP-IFN-CTP demonstrated a significant increase in in vitro thermal resistance and a higher stability against plasma protease inactivation, both features attributed to the stabilizing effects of the O-glycans provided by the CTP moiety. These results constitute the first report that postulates CTP as a tag for improving both the in vitro and in vivo stability of rhIFN-α2b which, in turn, would positively influence its in vivo bioactivity.

Removing a Cystein Group On Interferon Alpha 2b at Position 2 and 99 does Not Diminish Antitumor Activity of the Protein, Even Better

Interferon alpha 2b is the only standard therapeutic protein for hepatitis virus infections. Further study demonstrated that this protein also posseses antitumor activity in several cancerous organs. One main pathway of this antitumor activity is mediated through antiproliferation as well as proapoptotic effects. Previously, we have successfully developed recombinant human interferon alpha 2b (rhIFNα2b) by using a synthetic gene. In addition, two mutein forms of rhIFNα2b were generated to improve the characteristics of this protein. Two point mutations showed better pharmacokinetic profiles than one point mutation as well as the native form. In the present study, this mutein form was studied for ist antitumor effect in vitro using HepG2 cells. As a comparison, the native form as well as a commercial rIFNα2b were used. Several parameters were investigated including the MTT assay, cell viability test, cell cycle using flow cytometric analysis, and the genes and protein expressions involved in cell growth. The latest was observed to study the mechanism of rhIFNα2b. There was no significant difference in the MTT assay and cell viability after cells were treated with both forms of rhIFNα2b. However, the mutein rhIFNα2b tended to show better proapoptotic activity reflected by flow cytometric data, protein expression of pSTAT1, and DNA expression of caspase 3.

EFFICACY AND SAFETY OF A NEW COMBINED MEDICATION WITH RECOMBINANT INTERFERON AND BETAMETHASONE IN THE TREATMENT OF HAY FEVER DURING PERIODS OF EXACERBATION

Objective: to assess the efficacy, safety and tolerability of the new combined medication Allergoferon® beta in patients with moderate-to-severe hay fever (seasonal allergic rhinitis and conjunctivitis) during periods of exacerbation. patients and methods: the object of our study was medication Allergoferon® beta (recombinant human interferon alpha-2b, not less than 5000 IU/ml + betamethasone sodium phosphate, 1.0 mg/ml) in the form of eye and nasal drops. Total of 120 patients aged 18-65 years with hay fever for at least two years were enrolled in the clinical trial, including 76 women and 44 men. All patients had a clinical picture of moderate-to-severe hay fever during periods of exacerbation. Patients were divided into two equal groups. The main group received Allergoferon® beta, the control group was treated with Oftan® Dexamethasone and Nasobek medications. This trial used a randomized, open-label, multicenter, parallel, comparative, controlled study design. results: we found that new combined medication Allergoferon® beta had a significant therapeutic effect in relieving main clinical manifestations of acute hay fever and showed a higher efficacy, than the comparison remedies. By comparing similar symptoms in both groups, we observed that in patients treated with Allergoferon® beta clinical symptoms of acute hay fever were relieved earlier (on the 5th day of treatment), than in the control group (on the 10th day of treatment) and the disease itself proceeded milder. Therapeutic efficacy of Allergoferon® beta was 85,96% (in the control group — 74,73%, p&lt;0.05). During clinical trial we have not observed any adverse effects; general or local toxic and allergic reactions were also not discovered. The medication tolerability was rated as “good” for patients. Conclusion: according to the clinical study results, the medication Allergoferon® beta (eye and nasal drops) is recommended for the state registration and can be used by medical professionals in the treatment of moderate-to-severe hay fever (seasonal allergic rhinitis and conjunctivitis), including periods of exacerbation.

Obtaining of the transgenic Heliantus tuberosus L. plants, callus and “hairy” root cultures able to express the recombinant human interferon alpha-2b gene

This work is the first to our knowledge to describe the successful attempt of Agrobacterium rhizogenes-mediated transformation of topinambour in order to obtain the transgenic H. tuberosus plants, callus and "hairy" root cultures. The plasmid vectors contained the sequence of interferon gene fused with Nicotiana plumbagenifolia L. calreticulin apoplast targeting signal driven by 35S CaMV promoter or root-specific Mll promoter. Nearly 75% isolated Ri-root lines and callus cultures were proved (by PCR analysis) to contain HuINFa-2b transgene. We also managed to obtain H. tuberosus transgenic plants through somatic embryogenesis on the transgenic "hairy" root culture. The obtained transgenic H. tuberosus cultures exhibited high-level antiviral activity that ranged from 2000 to 54500 IU/g FW that makes this crop considered a promising source of recombinant interferon alpha 2b protein.

Production of human interferon alpha-2b in Escherichia coli and removal of N-terminal methionine utilizing archaeal methionine aminopeptidase

AbstractMethionine is the first amino acid residue in most of the recombinant proteins and sometimes it is necessary to remove the starting methionine in order to get foreign proteins with wild type sequences. Recombinant human interferon alpha-2b was produced in Escherichia coli in insoluble form as inclusion bodies, which were solubilized and refolded. Analysis of the purified recombinant protein indicated that it consisted of two types of molecules, one type, in majority, having N-terminal methionine intact, whereas the other type, in minority, having the N-terminal methionine cleaved by methionine aminopeptidase of the host. Both species were separated by high performance liquid chromatography and Nterminal methionine of the remaining molecules was removed by utilizing methionine aminopeptidase from Pyrococcus furiosus in order to get similar form of the interferon alpha-2b as produced by human body. The methodology developed in this study can be extended to other proteins of pharmaceutical importance.

ANTIPROLIFERATIVE ACTIVITY OF RECOMBINANT HUMAN INTERFERON ALPHA2B ON ESTROGEN POSITIVE HUMAN BREAST CANCER MCF-7 CELL LINE

Indonesia is the top three countries with hepatitis and moreover has 40.000 cancer mortalities per year. Interferon alpha 2b (IFNα-2b) is a therapeutic standard for cancer and hepatitis B/C treatments. We developed recombinant human interferon alpha 2b (rhIFNα-2b) in methilotropic yeast Pichia pastoris X-33. The protein was produced as extracellular protein with 24 kDa in size. This research was aimed to characterize the protein based on its amino acid sequence and to study its antiproliferative activity on MCF-7 cell line. Amino acid sequencing by using MALDI TOF TOF mass spectrometry with trypsin as proteolytic enzyme identified protein as hIFNα-2b with 33% of amino acid coverage. The antiproliferative activity was determined by 3-[4.5-dimethyltiazol-2il]-2.5-diphenylltetrazolium bromide (MTT) assay. Based on several studies about the synergistic activity of rhIFNα-2b with other anticancer drugs, we combined our rhIFNα-2b with tamoxifen (tmx). The growth percentage of the cells after being treated with 1µM of tmx at various concentrations of rhIFNα-2b was compared with that of untreated cell. This study showed that the antiproliferative activity was dose-dependently. Cell viability assay with calcein and ethidium bromide-based staining by fluorescence microscope confirmed that the rhIFNα-2b had ability to inhibit proliferation of human breast cancer cell line MCF-7. Keywords: human interferon alpha 2b, Pichia pastoris , antiproliferative and MCF-7

Novaferon, a novel recombinant protein produced by DNA-shuffling of IFN-α, shows antitumor effect in vitro and in vivo

ObjectiveA recombinant antitumor/antiviral protein (Novaferon, Nova) is a new type of interferon, which is produced by artificial design technology combining DNA-shuffling and High Throughput Screening (HTS).MethodsThe in vitro biological activities, such as anti-tumor activity and antiviral activity of Nova and recombinant human interferon alpha-2b (rhIFN-α2b) was performed; in vivo anti-tumor activity in nude mice was also tested. Flow cytometry, histo-pathological analysis including HE staining and immunohistochemistry, and surface plasmon resonance assay were performed to investigate the underlying mechanisms analysis.ResultsNova exhibited stronger anti-cancer effects compared to rhIFN-α2b in vitro and in vivo. The antitumor mechanisms of Nova may be related to S phase arrest, pro-apoptosis, and inhibition of tumor angiogenesis. Moreover, Nova exhibited a higher binding affinity for IFN receptor 2 (IFNR2) than rhIFN-α2b, which is one of the possible reasons accounting for its stronger actions against tumor cells compared with rhIFN-α2b.ConclusionNova has strong antitumor activity and could be a potentially effective therapeutic drug for cancer.

Study on the effect of solution conditions on heat induced-aggregation of human alpha interferon.

A major problem in the formulation of therapeutic proteins is the irreversible protein aggregation. Recombinant human interferon alpha2b (rhIFNα2b) has poor stability and undergoes physical degradation. The aim of this study was to investigate the effect of solution conditions on the heat-induced aggregation of rhIFNα2b. The protein was incubated for 1 h at 40-70 °C and for up to 240 h at 50 °C and its aggregation tendency was then studied using optical density (at 350 nm), SE-HPLC, dynamic light scattering and SDS-PAGE methods. The effect of various pH (5, 6 and 7) and buffer concentrations (10, 55 and 100 mM) on the aggregation of protein following incubation at 50 °C for 72 h was also evaluated. The results obtained for samples incubated at 50 °C for up to 240 h showed that OD350 and the amount of higher molecular weight aggregates (HMW) increased and the monomer content decreased significantly (p<0.05) as the incubation time increased. Following incubation at various temperatures, a significant increase in OD350, drop in monomer content and increase in the amount of HMW aggregates were observed (p<0.05). Data obtained from incubation of samples at 50 °C for 72 h confirmed that regardless of the buffer concentration, the percentage of monomer at pH 6 was significantly higher than that at pH 7 and pH 5 (p<0.05). At constant pH, although not significant, the same trend was observed when the buffer concentration increased to 100 mM. In conclusion, the change in solution conditions can influence the aggregation extent of rhIFNα2b.

Recovery of human interferon alpha-2b from recombinant Escherichia coli using alcohol/salt-based aqueous two-phase systems

The purification of intracellular human recombinant interferon-alpha2b (IFN-α2b) from Escherichia coli (E. coli) was studied using alcohol/salt aqueous two-phase system (ATPS). The influences of nine biphasic systems comprising alcohol-based top phase (ethanol, 1-propanol and 2-propanol) and salt-based bottom phase (ammonium sulfate, di-potassium hydrogen phosphate and monosodium citrate) on IFN-α2b purification were studied. The results showed that the optimum condition for purification of IFN-α2b was achieved in ATPS composed of 18% (w/w) 2-propanol with 22% (w/w) ammonium sulfate in the presence of 1% (w/w) sodium chloride (NaCl). The purified IFN-α2b recorded a purification factor (PF) of 16.24 with the yield of 74.64%.

Heterologous expression, immunochemical and computational analysis of recombinant human interferon alpha 2b

Interferon alpha 2b (IFNα-2b) is an important cytokine and used for antiviral and anticancer treatment. The low cost production of IFNα-2b with high biological activity is necessary to provide the interferon therapy to the hepatitis patients in Pakistan. In the present study, human interferon alpha 2b (hIFNα-2b) gene from a healthy person was cloned and overexpressed in E. coli BL21(DE3). The molecular weight of the expressed hIFNα-2b is 19 kDa. The over expressed recombinant hIFNα-2b was checked by ELISA using antibodies raised against commercially available hIFNα-2b. The biocomputational analysis of recombinant hIFNα-2b gene showed the 99.9% nucleotide sequence and 100% deduced amino acid sequence homology with reported sequences of IFNα-2b. The predicted 3D-structure showed mainly five α-helices, one 310 helix and two disulfide bonds at Cys1-Cys98 and Cys129-Cys138. The amino acid sequence alignment indicated that the disulfide linkage position is conserved in all IFNα family members. On the basis of sequence homology among interferon alpha family, new potent variants of hIFNα-2b with enhance efficacy can be produced. Indigenous production of IFNα-2b from gene of local population will reduce the cost and increase tolerability of interferon therapy.

Effects of topical ocular administration of high doses of human recombinant interferon alpha-2b and feline recombinant interferon omega on naturally occurring viral keratoconjunctivitis in cats

To determine whether 14-day topical ocular administration of high doses of feline recombinant interferon omega (FelFN) or human recombinant interferon alpha-2b (HulFN) solution improves clinical disease and decreases virus shedding in cats with naturally acquired viral keratoconjunctivitis. 36 cats with upper respiratory tract disease and ocular involvement. Cats received 1 drop of FelFN solution (1 × 10(6) U/mL), HulFN solution (1 × 10(6) U/mL), or saline (0.9% NaCl) solution (12 cats/group) in each eye twice daily for 14 days (beginning day 1). Oropharyngeal and conjunctival swab samples were collected from each cat before (day 0) and on day 14 of treatment for virus isolation (VI) and real-time quantitative PCR (RT-qPCR) testing to detect feline herpesvirus-1 and feline calicivirus. Subjective clinical scores were recorded on days 0, 3, 7, 10, and 14. The number of cats for which feline herpesvirus-1 was detected via VI or RT-qPCR assay was generally (albeit not always significantly) lower on day 14, compared with day 0 findings; however, findings on days 0 or 14 did not differ among groups. The number of cats for which feline calicivirus was detected via VI or RT-qPCR assay did not differ significantly between days 0 and 14 for any group. Clinical scores significantly decreased over the 14-day period but did not differ among groups. In cats with naturally occurring viral keratoconjunctivitis, bilateral ocular administration of high doses of FelFN or HulFN twice daily for 14 days did not improve clinical disease or virus shedding, compared with treatment with saline solution.

Evaluation of Adverse Effects of Mutein Forms of Recombinant Human Interferon Alpha-2b in Female Swiss Webster Mice

Purpose. We successfully developed recombinant human interferon alpha-2b (rhIFN-α2b) and mutein forms through the site-directed mutagenesis technique. The mutein forms were developed by substituting cysteins at positions 2 and 99 with aspartic acids. The potential adverse effects of these rhIFN-α2bs were assessed by acute and subchronic studies. Methods. In the acute study, rhIFN-α2bs were subcutaneously administered to mice at a single dose of 97.5 μg/kg, 975 μg/kg, and 9.75 mg/kg BW and were observed for 14 days. In the subchronic study, single dose of 1.95 μg/kg and 19.5 μg/kg, respectively, was given subcutaneously every 3 days for 45 days. Results. No death as well as abnormality in body weight, behavior, presentation of main organs, and value of plasma SGPT and SGOT was observed. Wild type and mutein rhIFN-α2bs did not show significant adverse effects at dose up to 9.75 mg/kg BW. Administration of these rhIFN-α2bs given repeatedly did not induce any adverse effect. Conclusion. These results suggest that our rhIFN-α2bs are safe. However, further study is still needed to clarify the safety issue before use in clinical trial.

Recovery of Human Interferon Alpha-2b from Recombinant Escherichia coli by Aqueous Two-Phase System

Recovery of periplasmic human recombinant interferon alpha-2b (IFN-α2b) from Escherichia coli rosetta-gami2 (DE3) using a single-step polyethylene glycol (PEG)-potassium phosphate aqueous two-phase system (ATPS) was investigated in this study. The influences of system parameters including PEG molecular weight, tie-line length, volume ratio, crude stock loading, system pH, and sodium chloride (NaCl) concentration (%, w/w) were studied. The results showed that the optimum condition to obtain the high purification factor of IFN-α2b in a single step was achieved by ATPS composed of 4% (w/w) PEG 8000, 13% (w/w) potassium phosphate, 0.5% (w/w) NaCl, 10% (w/w) crude stock, and a system pH of 6.5. A purification factor of 26.3 and recovery yield of 40.7% were obtained from optimized ATPS.

Controlled-release interferon alpha 2b, a new member of the interferon family for the treatment of chronic hepatitis C

Introduction: Combination therapy with pegylated interferon alpha (Peg-interferon) and ribavirin is currently the cornerstone of antiviral therapy for chronic hepatitis C. Monotherapy with Peg-interferon still is important for the treatment of chronic hepatitis B. With the advent of new therapies, protease inhibitors for chronic hepatitis C and nucleotide inhibitors for chronic hepatitis B, there remains a need for interferon-based therapies. The side effects of Peg-interferon are a main disadvantage and represent a stumbling block for many patients to enter and continue therapy.Areas covered: In this review, the authors will discuss controlled-release interferon alpha 2b (CR2b) (Locteron®, Biolex Therapeutics, Pittsboro, NC, USA), a new slow-release interferon alpha 2b preparation for the treatment of chronic viral hepatitis. Other alternative interferons will also be discussed.Expert opinion: CR2b is a slow-release microsphere preparation for the administration of plant-derived recombinant human interferon alpha 2b. Compared with Peg-interferon, treatment with CR2b shows less flu-like reactions and less depression, and is at least as effective as conventional Peg-interferon-based therapy in patients with chronic hepatitis C. CR2b has the added advantage of biweekly instead of once weekly administration. CR2b appears to cause more neutropenia than Peg-interferon alpha 2b. This may be due to higher trough serum levels of CR2b at the end of a dosing interval. The bone marrow effects of CR2b closely resemble those published for the registered Peg-interferon alpha 2a. CR2b appears to have at least comparable efficacy with fewer side effects than current registered Peg-interferons.