OBJECTIVE: To investigate the regulatory effect of interferon-α (IFN-α) on the apoptosis and killing function of CD56^dimCD57⁺ natural killer (NK) cells in systemic lupus erythematosus (SLE) patients, and to explore the specific mechanism. METHODS: A total of sixty-four newly treated SLE patients and sixteen healthy controls (HC) enrolled in the Second Hospital of Dalian Medical University were selected as the research subjects. And the gene expression levels of molecules related to NK cell-killing function were detected by real-time quantitative polymerase chain reaction. CD56^dimCD57⁺ NK cells were co-cultured with the K562 cells, and the apoptotic K562 cells were labeled with Annexin-Ⅴ and 7-amino-actinomycin D. Peripheral blood mononuclear cells were treated with 20, 40, and 80 μmol/L hydrogen peroxide (H₂O₂), and treated without H₂O₂ as control, the expression level of perforin (PRF) was detected by flow cytometry. The concentration of IFN-α in serum was determined by enzyme linked immunosorbent assay. The expression levels of IFN-α receptors (IFNAR) on the surface of CD56^dimCD57⁺ NK cells were detected by flow cytometry, and were represented by mean fluorescence intensity (MFI). CD56^dimCD57⁺ NK cells were treated with 1 000 U/mL IFN-α for 24, 48 and 72 h, and no IFN-α treatment was used as the control, the apoptosis and the expression levels of mitochondrial reactive oxygen species (mtROS) were measured by flow cytometry and represented by MFI. RESULTS: Compared with HC(n=3), the expression levels of PRF1 gene in peripheral blood NK cells of the SLE patients (n=3) were decreased (1.24±0.41 vs. 0.57±0.12, P=0.05). Compared with HC(n=5), the ability of peripheral blood CD56^dimCD57⁺ NK cells in the SLE patients (n=5) to kill K562 cells was significantly decreased (58.61%±10.60% vs. 36.74%±6.27%, P < 0.01). Compared with the control (n=5, 97.51%±1.67%), different concentrations of H₂O₂ treatment significantly down-regulated the PRF expression levels of CD56^dimCD57⁺ NK cells in a dose-dependent manner, the 20 μmol/L H₂O₂ PRF was 83.23%±8.48% (n=5, P < 0.05), the 40 μmol/L H₂O₂ PRF was 79.53%±8.56% (n=5, P < 0.01), the 80 μmol/L H₂O₂ PRF was 76.67%±7.16% (n=5, P < 0.01). Compared to HC (n=16), the serum IFN-α levels were significantly increased in the SLE patients (n=45) with moderate to high systemic lupus erythematosus disease activity index (SLEDAI≥10) [(55.07±50.36) ng/L vs. (328.2±276.3) ng/L, P < 0.001]. Meanwhile, compared with HC (n=6), IFNAR1 expression in peripheral blood CD56^dimCD57⁺ NK cells of the SLE patients (n=6) were increased (MFI: 292.7±91.9 vs. 483.2±160.3, P < 0.05), and compared with HC (n=6), IFNAR2 expression in peripheral blood CD56^dimCD57⁺ NK cells of the SLE patients (n=7) were increased (MFI: 643.5±113.7 vs. 919.0±246.9, P < 0.05). Compared with control (n=6), the stimulation of IFN-α (n=6) significantly promoted the apoptosis of CD56^dimCD57⁺ NK cells (20.48%±7.01% vs. 37.82%±5.84%, P < 0.05). In addition, compared with the control (n=4, MFI: 1 049±174.5), stimulation of CD56^dimCD57⁺ NK cells with IFN-α at different times significantly promoted the production of mtROS in a time-dependent manner, 48 h MFI was 3 437±1 472 (n=4, P < 0.05), 72 h MFI was 6 495±1 089 (n=4, P < 0.000 1), but there was no significant difference at 24 h of stimulation. CONCLUSION High serum IFN-α level in SLE patients may induce apoptosis by promoting mtROS production and inhibit perforin expression, which can down-regulate CD56^dimCD57⁺ NK killing function.
Humans ; Interferon-alpha/metabolism* ; Perforin/metabolism* ; Leukocytes, Mononuclear/metabolism* ; Hydrogen Peroxide/metabolism* ; Interferon-gamma/metabolism* ; CD56 Antigen/metabolism* ; Killer Cells, Natural/metabolism* ; Lupus Erythematosus, Systemic

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

The effect of induction temperature on aggregation of consensus interferon-alpha expressed by Pichia pastoris was investigated. The cell growth and cIFN level were analyzed and compared when Pichia pastoris was grown at 30,25,20 degrees C during induction phase, using 5.0L fermentor. The result suggested that the cell growth was not affected much under the different induction temperature, but the protein level declined markedly with the decrease of the induction temperature. The total protein ammount induced at 20 degrees C was 67.8 percent of that at 30 degrees C. SDS-PAGE and native-PAGE as well as Western blotting analysis were further conducted. The electrophoresis results revealed that cIFN formed aggregates after secreted into media when protein was induced at 30 degrees C but this problem can be restored by decreasing the induction temperature to 20 degrees C. cIFN monomer in supernatant arrived at 570mg/L and bioactivity of fermentation broth reached 1.05 x 10(9) IU/mL at 20 degrees C of induction temperature. The amount of cIFN monomer and bioactivity in supernatant elevated 7.2 and 38.7 times, respectively, when the induction temperature was controlled at 20 degrees C instead of conventional 30 degrees C.
Fermentation ; Humans ; Interferon Type I ; biosynthesis ; genetics ; Interferon-alpha ; Pichia ; genetics ; growth & development ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; Temperature

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

OBJECTIVETo study the effects of andrographolide on immune functions and the immune mechanism of its clinical application.

METHODThe amounts of IFN-alpha, IFN-gamma, TNF-alpha, IL-8 in the peripheral blood mononuclear cells(PBMCs) culture supernatants deal with by different concentrations of LianBiZhi (LBZ) injection made of andrographolide were detected by biological activity test or ELISA in vitro. The effects of LBZ injection on macrophage phagocytotic function and natural killer cells cytotoxicity were examined by means of macrophage to phagocytize cock erythrocyte and measurement of lactate dehydrogenase(LDH) activity released from the damaged cells, respectively.

RESULTThe LBZ injection could promote IFN-alpha, IFN-gamma, TNF-alpha inductions of PBMCs, but had no effect on IL-8. At the same time, the LBZ injection could not only enhance the phagocytosis activity of peritoneal macrophage from guinea pig to phagocytosis cock erythrocyte, but also augment the cytotoxicity mediated by natural killer cells from PBMCs to damage the K562 cell lines.

CONCLUSIONAndrographolide is an immunostimulant agent which can modulate both antigen specific and nonspecific immune function by means of its natural killer cells and macrophage and cytokines induction.

Animals ; Anti-Inflammatory Agents, Non-Steroidal ; pharmacology ; Chickens ; Diterpenes ; pharmacology ; Guinea Pigs ; Humans ; Injections ; Interferon-alpha ; metabolism ; Interferon-gamma ; metabolism ; Killer Cells, Natural ; drug effects ; Macrophages, Peritoneal ; drug effects ; Neutrophils ; metabolism ; Phagocytosis ; drug effects ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo construct a recombinant bacillus Calmette-Guérin vaccine (rBCG) secreting human interferon-alpha 2b (IFN alpha-2b).

METHODSBCG Ag85B signal sequence and IFN alpha-2b gene were amplified from the genome of BCG and of human peripheral blood by polymerase chain reaction (PCR), respectively. IFN alpha-2b gene was cloned in E. coli-BCG shuttle-vector pMV261 to get pMV261-IFN alpha-2b. A new recombinant plasmid pMV261-IFN alpha-2b was constructed by inserting BCG Ag85B signal sequence into pMV261-Ag85B-IFN alpha-2b. Then, BCG was transformed with this recombinant plasmid by electroporation, and designated as rBCG-IFN alpha-2b. The DNA and protein expressions of IFN alpha-2b gene in rBCG were determined by PCR and Western blot respectively. Also the quantity of IFN alpha-2b protein secreted by rBCG in culture supernatants was determined by enzyme linked immunosorbent assay (ELISA).

RESULTSBy partial nucleotide sequencing, the DNA sequences of human IFN alpha-2b and BCG Ag85B were consistent with that in the Gene Bank, and were correctly inserted into the shuttle expression vector pMV261 to construct recombinant plasmid pMV261-Ag85B-IFN alpha-2b. BCG was successfully transformed with this recombinant plasmid by electroporation and the recombinant BCG (rBCG-IFN alpha-2b) was capable of synthesizing and secreting cytokine IFN alpha-2b. The concentration of IFN alpha-2b in culture supernatants was quantified by ELISA and calculated to be approximately 301.45 pg/ml.

CONCLUSIONSRecombinant BCG secreting human IFN alpha-2b (rBCG-IFN alpha-2b) was constructed successfully and the specific IFN alpha-2b protein can be expressed highly and steadily by rBCG vaccine.

BCG Vaccine ; genetics ; immunology ; metabolism ; Gene Expression ; Genetic Vectors ; Humans ; Interferon-alpha ; genetics ; metabolism ; Plasmids ; genetics ; Recombinant Proteins ; Transformation, Bacterial

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

OBJECTIVES: To study the expression of V-domain Ig suppressor of T cell activation (VISTA) in peripheral blood of children with juvenile idiopathic arthritis (JIA) and its role in the pathogenesis of JIA. METHODS: In this prospective study, peripheral blood was collected from 47 children with different subtypes of JIA and 10 healthy children. Flow cytometry was used to measure the expression levels of VISTA, interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α) on CD14⁺ mononuclear cells, CD4⁺ T lymphocytes, and CD8⁺ T lymphocytes. RESULTS: The children with JIA had a significantly lower expression level of VISTA than the healthy children (P<0.05). There was a significant difference in the expression of VISTA between the children with different subtypes of JIA, with the lowest expression level in those with systemic JIA (P<0.05). There was also a significant difference in the expression of VISTA between different immune cells, with a significantly higher expression level on the surface of monocytes (P<0.05). Correlation analysis showed that VISTA was negatively correlated with the expression of IFN-γ and TNF-α on CD4⁺ T cells (r=-0.436 and -0.382 respectively, P<0.05), CD8⁺ T cells (r=-0.348 and -0.487 respectively, P<0.05), and CD14⁺ mononuclear cells (r=-0.582 and -0.603 respectively, P<0.05). CONCLUSIONS The insufficient expression of VISTA may be associated with the pathogenesis of JIA, and enhancing the immunomodulatory effect of VISTA might be one option for the treatment of JIA in the future.
Child ; Humans ; Arthritis, Juvenile/pathology* ; Tumor Necrosis Factor-alpha/metabolism* ; CD8-Positive T-Lymphocytes ; Prospective Studies ; Interferon-gamma/metabolism*

Objective To identify the relationship between nephritis activity, autophagy and inflammation in patients with SLE. Methods Western blot analysis was used to detect the expression of microtubule-associated protein 1 light chain 3 (LC3) and P62 in peripheral blood mononuclear cells (PBMCs) of SLE patients with lupus nephritis and non-lupus nephritis patients. Tumor necrosis factor α (TNF-α) and interferon γ (IFN-γ) in the serum of SLE patients were determined by ELISA. The correlation between LC3II/LC3I ratio and SLE disease activity score (SLEDAI), urinary protein, TNF-α and IFN-γ levels was analyzed by Pearson method. Results The expression of LC3 was increased and P62 was decreased in SLE patients. TNF-α and IFN-γ were increased in the serum of SLE patients. LC3II/LC3I ratio was positively correlated with SLEDAI (r=0.4560), 24 hour urine protein (r=0.3753), IFN-γ (r=0.5685), but had no correlation with TNF-α (r=0.04 683). Conclusion Autophagy is found in PBMCs of SLE, and the autophagy is correlated with renal damage and inflammation in patients with lupus nephritis.
Humans ; Tumor Necrosis Factor-alpha/metabolism* ; Leukocytes, Mononuclear/metabolism* ; Autophagy-Related Proteins/metabolism* ; Lupus Nephritis/urine* ; Kidney ; Interferon-gamma/metabolism* ; Inflammation/metabolism* ; Lupus Erythematosus, Systemic/metabolism*

BACKGROUNDAlthough the onset of anemia during infectious disease is commonly correlated with production of inflammatory cytokines, the mechanisms by which cytokines induce anemia are poorly defined. This study focused on the mechanism research.

METHODSDifferent types of mice were infected perorally with Toxoplasma gondii strain ME49. At the indicated times, samples from each mouse were harvested, processed, and analyzed individually. Blood samples were analyzed using a Coulter Counter and red blood cell (RBC) survival was measured by biotinylation. Levels of tumor necrosis factor-&alpha; (TNF-&alpha;), inducible nitric oxide synthase (iNOS), and inducible protein 10 (IP-10) mRNA in liver tissue were measured by real-time polymerase chain reaction.

RESULTST. gondii-infected mice exhibited anemia due to a decrease in both erythropoiesis and survival time of RBC in the circulation (P < 0.02). In addition, infection-stimulated anemia was associated with fecal occult, supporting previous literature that hemorrhage is a consequence of T. gondii infection in mice. Infection-induced anemia was abolished in interferon gamma (IFNγ) and IFNγ receptor deficient mice (P < 0.05) but was still evident in mice lacking TNF-&alpha;, iNOS, phagocyte NADPH oxidase or IP-10 (P < 0.02). Neither signal transducer and activator of transcription 1 (STAT1) deficient mice nor 129S6 controls exhibited decreased erythropoiesis, but rather suffered from an anemia resulting solely from increased loss of circulating RBC.

CONCLUSIONSInfection-stimulated decrease in erythropoiesis and losses of RBC have distinct mechanistic bases. These results show that during T. gondii infection, IFNγ is responsible for an anemia that results from both a decrease in erythropoiesis and a STAT1 independent loss of circulating RBC.

Anemia ; genetics ; metabolism ; Animals ; Erythrocytes ; pathology ; Interferon-gamma ; metabolism ; Male ; Mice ; Mice, Knockout ; Nitric Oxide Synthase Type II ; genetics ; metabolism ; Receptors, Interferon ; genetics ; metabolism ; STAT1 Transcription Factor ; genetics ; metabolism ; Toxoplasma ; pathogenicity ; Tumor Necrosis Factor-alpha ; genetics ; metabolism