The study was aimed to investigate the synergistically effect of interferon-&alpha; (IFN-&alpha;) and homoharringtonine (HHT) on the proliferation, apoptosis, cell cycle of K562 cells and the expression of β-catenin. The proliferation, apoptosis, cell cycle and β-catenin mRNA expression of K562 cells treated with IFN-&alpha; and/or HHT were assayed with MTT, flow cytometry or RT-PCR respectively. The results showed that HHT alone, but not IFN-&alpha; alone, displayed a proliferation inhibition, apoptosis induction, G(0)/G(1) phase block and down-regulation of β-catenin expression in K562 cells with concentration- and time-dependent manners. The expression level of β-catenin mRNA after being treated with HHT was 0.5576 ± 0.0373, which were lower than that in control group (0.9369 ± 0.0142). The down-regulation of β-catenin expression in group of IFN-&alpha; combined with HHT was higher significantly than that in HHT group (0.3737 ± 0.0529 vs 0.5576 ± 0.0373, P < 0.05). Otherwise, HHT combined with IFN-&alpha; did not demonstrate obvious toxicologic effect on bone marrow mononuclear cells. It is concluded that IFN-&alpha; combined with HHT can enhance the cytotoxic effect of HHT on K562 cells, which may be associated with down-regulation of β-catenin expression.
Cell Proliferation ; drug effects ; Harringtonines ; pharmacology ; Humans ; Interferon-alpha ; pharmacology ; K562 Cells ; beta Catenin ; genetics ; metabolism

Both IFN-omega and IFN-alpha belong to type I interferon and have antiviral, antiproliferative, immunomodulatory activities, but their bioactivities are usually different. FeIFN-omega gene was amplified by PCR. FeIFN-alpha gene was synthesized based on the published sequences of GenBank. Then the two types of feline interferon genes were subcloned into the pET-His vector, and expressed in Escherichia coli Rosetta (DE3). Recombinant interferons were purified by affinity chromatography with immobilized nickel chelating NTA (Ni-NTA) and their antiviral activity was estimated according to the ability of IFNs to inhibit the cytopathic effects (CPE) of virus on cells. Results showed that the antiviral activities against various viruses of FeIFN-omega were higher than those of FeIFN-alpha. Against H9N2 subtype avian influenza virus (AIV) and canine distemper virus (CDV), the antiviral activities of FeIFN-omega were 160 folds and 4 folds higher than those of FeIFN-alpha.
Animals ; Antiviral Agents ; pharmacology ; Cats ; Distemper Virus, Canine ; drug effects ; Influenza A Virus, H9N2 Subtype ; drug effects ; Interferon Type I ; biosynthesis ; genetics ; pharmacology ; Interferon-alpha ; biosynthesis ; genetics ; pharmacology

BACKGROUNDTo study the anti-SARS virus activities of different recombinant human interferons on the cell culture system.

METHODSAnti-SARS virus activities of interferons were determined by using CPE inhibition test in human skeletal muscle sarcoma (Rda) cell culture.

RESULTSThe average minimum amount of interferon alpha 2b, alpha 1b, beta 1b or omega 1b to inhibit 50% CPE in Rda cell culture was (160.5+/-129.5) IU/ml, (149.0+/-71.7) IU/ml, (69.5+/-61.5) IU/ml, (87.3+/-47.1) IU/ml, respectively or (0.6+/-0.5) ng/ml, (10.6+/-5.1) ng/ml, (3.5+/-3.1) ng/ml, (0.9+/-0.5) ng/ml, respectively.

CONCLUSIONAll the tested recombinant interferons showed anti-SARS virus activities on the Rda cell culture with different sensitivities.

Antiviral Agents ; pharmacology ; Cell Line, Tumor ; Humans ; Interferon Type I ; pharmacology ; Interferon-alpha ; pharmacology ; Recombinant Proteins ; SARS Virus ; drug effects ; Severe Acute Respiratory Syndrome ; drug therapy ; virology

OBJECTIVETo detect the effect of interferon-&alpha;2a(IFN-&alpha;2a) on thymidine phosphorylase(TP) mRNA expression levels and the anticancer activity of 5-fluorouracil(5-FU) and 5'-deoxy-fluorouridine(5'-DFUR) in human colon carcinoma cell lines LOVO and SW480.

METHODSTwo human colon cancer cell lines LOVO and SW480 were cultured and treated with IFN-&alpha;2a at a series of dosage, and fluorescence quantitative PCR was carried out to detect the TP mRNA expression levels in these 2 cell lines. Then MTT assay and software Templet were used to determine the change of 50% inhibition concentration of 5-FU or 5'-DFUR combined with IFN-&alpha;2a on the two cell lines.

RESULTSThe TP mRNA expressions were up-regulated significantly by IFN-&alpha;2a at the doses of 500 U/ml and 5000 U/ml in LOVO(P<0.01). Compared with untreated cells(IFN-&alpha;2a 0 U/ml), no significance was found for TP mRNA expression levels in LOVO and SW480 treated by IFN-&alpha;2a at the dose of 50 U/ml (P>0.05). There was no significant difference for TP mRNA expression in SW480 between the dose of 0 U/ml and 500 U/ml of IFN-&alpha;2a(P>0.05), while a significant increace was detected at the dose of 5000 U/ml (P<0.01). No significant difference was found for the IC50 values after treatment of 5-FU combined with IFN-&alpha;2a (20 U/ml) on LOVO and SW480 compared with 5-FU alone, while the IC50 values after treatment of 5'-DFUR combined with IFN-&alpha;2a decreased significantly compared with 5'-DFUR alone(P<0.05).

CONCLUSIONThere is no direct inhibition effect of IFN-&alpha;2a on LOVO and SW480 in vitro, while it can up-regulate TP mRNA expression levels both in LOVO and SW480, and enhance the anticancer effect of 5'-DFUR on these 2 cell lines.

Cell Line, Tumor ; Colonic Neoplasms ; enzymology ; pathology ; Floxuridine ; pharmacology ; Humans ; Interferon-alpha ; pharmacology ; Recombinant Proteins ; pharmacology ; Thymidine Phosphorylase ; metabolism

Celecoxib ; Cell Proliferation ; drug effects ; Drug Resistance, Multiple ; Humans ; Interferon-alpha ; pharmacology ; K562 Cells ; Pyrazoles ; pharmacology ; Sulfonamides ; pharmacology

PEGylation is considered one of the most successful techniques to improve the characteristics of protein drugs including to increase the circulating half-life of proteins in blood and to decrease their immunogenicity and antigenicity. One known PEG modification method is to attach PEG to the free amino group, typically at lysine residues or at the N-terminal amino acid with no selectivity, resulting in a heterogeneous product mixture. This lack of selectivity can present problems when a therapeutic PEGylated protein is being developed, because predictability of activity and manufacturing reproducibility are needed for regulatory approval. Enzymatic PEGylation of proteins is one route to overcome this limitation. Transglutaminases (TGase) are enzyme candidates for site-specific PEGylation. We use human interferon alpha 2a (IFN α2a) as a test case, and predict that the potential modification residues are Gln101 by computational approach as it contains 12 potential PEGylation sites. IFN α2a was PEGylated by Y shaped PEG40k-NH2 mediated by microbial transglutaminase. Our results show that the microbial transglutaminase mediated PEGylation of IFN α2a was site-specific only at the site of Gln101 in IFN α2a, yielding the single mono-conjugate PEG-Gln101-IFN α2a with a mass of 59 374.66 Da. Circular dichroism studies showed that PEG-Gln101-IFN α2a preserved the same secondary structures as native IFN α2a. As expected, the bioactivity and pharmacokinetic profile in rats of PEG-Gln101-IFN α2a revealed a significant improvement to unmodified IFN α2a, and better than PEGASYS.
Animals ; Antiviral Agents ; Humans ; Interferon alpha-2 ; metabolism ; Interferon-alpha ; biosynthesis ; pharmacokinetics ; Polyethylene Glycols ; pharmacokinetics ; Protein Structure, Secondary ; Rats ; Recombinant Proteins ; biosynthesis ; pharmacokinetics ; pharmacology ; Reproducibility of Results ; Transglutaminases ; metabolism

BACKGROUNDHaptoglobin (Hp) is one of the acute-phase proteins. Recent studies have demonstrated that Hp exerts immunoregulatory and anti-inflammatory actions and may be one of the inhibitory factors of immune reactions in the skin. In this study we investigated the regulation of Hp expression in a human keratinocyte cell line HaCaT by various cytokines and glucocorticoid.

METHODSHaCaT cells were cultured with IL-6 (50 ng/ml), TNF-alpha (20 ng/ml), IFN-gamma (20 ng/ml) or IL-4 (20 ng/ml) with or without 1 micromol/L dexamethasone in 6-well plates for 12, 24 and 48 hours. Both the cells and the supernatants were collected to detect the changes of Hp expression by reverse-transcription PCR, ELISA and immunohistochemistry.

RESULTSThe results showed that Hp expression were elevated at both the mRNA and protein level by the combination of IL-6, TNF-alpha or IL-4 with dexamethasone, whereas the three cytokines alone did not upregulate the Hp expression. IFN-gamma showed no effect on the Hp expression in HaCaT cells.

CONCLUSIONSThese findings suggest that different inflammatory cytokines as well as glucocorticoid may be involved in the regulation of Hp expression in keratinocytes, and this may be one of the negative feedback mechanisms in inflammatory skin diseases.

Cell Line ; Dexamethasone ; pharmacology ; Glucocorticoids ; pharmacology ; Haptoglobins ; analysis ; Humans ; Interferon-gamma ; pharmacology ; Interleukin-4 ; pharmacology ; Interleukin-6 ; pharmacology ; Keratinocytes ; chemistry ; drug effects ; Tumor Necrosis Factor-alpha ; pharmacology

OBJECTIVETo explore the effect of astragalus polysaccharide (APS) on the function and maturation of chronic myelogenous leukemia (CML) peripheral blood mononuclear cells (PBMC)-derived plasmacytoid dendritic cells (pDCs).

METHODSCML-derived pDCs were sorted by flow cytometry, and then incubated with APS (at 0, 50, 100 and 200 mg/L). After 24 hours, the concentrations of IFN-&alpha;, IL-6, TNF-&alpha; were detected with ELISA. Five days later, the cultured cells were collected and analyzed for immotype, morphology and ultramicrostructure.

RESULTSThe level of IFN-&alpha;, IL-6, TNF-&alpha; was significantly higher in samples from CML remission group than that in untreated pDCs, and newly diagnosed pDC (P < 0.05) or untreated group. APS could promote more pDCs differentiating to dendritic cells (DCs) in CML remission group than in untreated-pDCs in a dose-dependant manner (P < 0.05).

CONCLUSIONAPS can enhance the immune function of pDCs, promote differentiation and maturation of pDCs from CML patients.

Cells, Cultured ; Dendritic Cells ; immunology ; Humans ; Interferon-alpha ; pharmacology ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; immunology ; Leukocytes, Mononuclear ; Polysaccharides ; pharmacology

Porcine interferon-alpha (pIFN-alpha) fermentative production by recombinant Pichia pastoris was carried out in a 10-L bioreactor to study its metabolism changes and effects on fermentation under different inducing strategies, by analyzing the change patterns of the corresponding metabolism and energy regeneration. The results show that the specific activities of alcohol oxidase (AOX), formaldehyde dehydrogenase (FLD) and formate dehydrogenase (FDH) largely increased when reducing temperature from 30 degrees C to 20 degrees C under pure methanol induction, leading significant enhancements in methanol metabolism, formaldehyde dissimilatory energy metabolism and pIFN-alpha antiviral activity. The highest pIFN-alpha antiviral activity reached 1.4 x 10(6) IU/mL, which was about 10-folds of that obtained under 30 degrees C induction. Using methanol/sorbitol co-feeding strategy at 30 degrees C, the major energy metabolism energizing pIFN-alpha synthesis shifted from formaldehyde dissimilatory energy metabolism pathway to TCA cycle, formaldehyde dissimilatory pathway was weakened and accumulation of toxic intermediate metabolite-formaldehyde was relieved, and methanol flux distribution towards to pIFN-alpha synthesis was enhanced. Under this condition, the highest pIFN-alpha antiviral activity reached 1.8 x 10(7) IU/mL which was about 100-folds of that obtained under pure methanol induction at 30 degrees C. More important, enhanced pIFN-alpha production with methanol/sorbitol co-feeding strategy could be implemented under mild conditions, which greatly reduced the fermentation costs and improved the entire fermentation performance.
Animals ; Energy Metabolism ; Fermentation ; Interferon-alpha ; biosynthesis ; genetics ; Methanol ; pharmacology ; Pichia ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; Sorbitol ; pharmacology ; Swine

BACKGROUNDBased on the earlier mapping of the epitope recognized by neutralizing antibody, the authors directly replaced binding domain of IFN in AB-loop for enhancement of biological activity.

METHODSTwo unique restriction sites (EcoR? and BsE?) were created into region flanking LoopAB. Casette mutagesis, restriction enzyme digestion, DNA sequencing, antiviral activity assay and antiproliferative activity assay have been used in the project.

RESULTSThe mutated residues M31?D,D32?P of LoopAB in parent IFN were produced. The recombinant phagemid pCANTAB5E/3132IFN 1c/86D and expression plasmid PBV322-132IFN 1c/86D were constructed respectively by replacing the corresponding LoopAB with DNA fragment mutated in the residues M31?D,D32?P, which have been confirmed. The recombinant protein has been expressed in E.coli JM103. The crude 3132IFN 1c/86D has been assayed on human WISH cells challenged with VSV and on HeLa cells by colorimetric MTT. 3132IFN 1c/86D showed 8-old antiviral activity compared to that of parent IFN 1c/86D, while IFN?induced growth inhibition of both types had no difference.

CONCLUSIONSThe authors concluded that a mutant IFN with enhanced antiviral activity can be obtained via a targeted replacement of receptor binding domain in AB-loop.

Amino Acid Substitution ; Antibodies, Viral ; Antiviral Agents ; pharmacology ; Cells, Cultured ; DNA Mutational Analysis ; Humans ; Interferon Type I ; genetics ; pharmacology ; Interferon-alpha ; Mutagenesis, Site-Directed ; Mutation ; Peptide Fragments ; genetics ; pharmacology ; Plasmids ; genetics ; Receptors, Interferon ; metabolism ; Recombinant Proteins