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Xie C.,Sun Yat Sen University | Xie C.,Shenzhen Weiguang Biological Products Co. | Chen W.,Guangzhou University | Chen W.,Gene Science and Health company | And 5 more authors.
FEBS Letters | Year: 2015

Abstract Despite extensive investigation into the role of let-7 miRNAs in pathological tumor processes, their involvement in the DNA damage response remains unclear. Here we show that most let-7 family members down-regulate MDM4 expression via binding to MDM4 mRNA at a conserved DNA sequence. Expression of exogenous let-7 miRNA mimics decreased MDM4 protein but not mRNA levels. Several DNA damage reagents increased let-7 expression, thereby decreasing MDM4 protein levels in glioma cells. Inhibition of endogenous let-7 with antisense RNAs rescued MDM4 protein levels with or without MG132, a proteasome-dependent degradation inhibitor. An MDM4 mutation identified in a glioma patient was associated with loss of the putative MDM4 target site. Therefore, let-7 binding to MDM4 is implicated in the DNA damage response. © 2015 Federation of European Biochemical Societies. Source

Shenzhen Weiguang Biological Products Co. | Date: 2011-08-16

The present invention discloses an intravenous cytomegalovirus human immune globulin and a manufacturing method thereof, wherein the technical problem to be solved is to improve the purity, yield, and safety of the product. The intravenous cytomegalovirus human immune globulin of the present invention has a specific activity of no less than 2.5 PEI-U/mg, an anti-CMV titer of no less than 100 PEI-U/ml, a purity of greater than 98.2%, and a protein content of 5155 mg/ml. The present invention employs caprylic acid precipitation and anion exchange chromatography for replacing the step of ethanol precipitation in the conventional cold ethanol method to keep IgG in the supernatant and maintain the activity of the IgG; the present invention employing processes of caprylic acid inactivation of virus and nanometer film virus removal can effectively protect the safety of the product, and studies show that the preparing method of the present invention not only improves the purity, yield, and safety of the product; but also saves energy and reduces the cost of production.

Zhu S.,Shenzhen Weiguang Biological Products Co. | Li H.,Shenzhen Weiguang Biological Products Co. | Wang C.,Shenzhen Weiguang Biological Products Co. | Luo F.,Shenzhen Weiguang Biological Products Co. | Guo C.,Shenzhen Weiguang Biological Products Co.
Journal of NeuroVirology | Year: 2015

Rabies is an ancient neurological disease that is almost invariably fatal once the clinical symptoms develop. Currently, prompt wound cleansing after exposing to a potentially rabid animal and vaccination using rabies vaccine combined with administration of rabies immune globulin are the only effective methods for post-exposure prophylaxis against rabies. Reverse genetic technique is a novel approach to investigate the function of a specific gene by analyzing the phenotypic effects through directly manipulating the gene sequences. It has revolutionized and provided a powerful tool to study the molecular biology of RNA viruses and has been widely used in rabies virus research. The attenuation of rabies virus virulence is the prerequisite for rabies vaccine development. Given the current challenge that sufficient and affordable high-quality vaccines are limited and lacking for global rabies prevention and control, highly cell-adapted, stable, and attenuated rabies viruses with broad cross-reactivity against different viral variants are ideal candidates for consideration to meet the need for human rabies control in the future. A number of approaches have been pursued to reduce the virulence of the virus and improve the safety of rabies vaccines. The application of reverse genetic technique has greatly advanced the engineering of rabies virus and paves the avenue for utilizing rabies virus for vaccine against rabies, viral vectors for exogenous antigen expression, and gene therapy in the future. © 2015, Journal of NeuroVirology, Inc. Source

Guo C.-P.,Shenzhen Weiguang Biological Products Co. | Wang C.-H.,Shenzhen Weiguang Biological Products Co. | Zhou L.-Z.,Shenzhen Weiguang Biological Products Co. | Liu Y.-D.,Shenzhen Weiguang Biological Products Co. | And 3 more authors.
Chinese Journal of Biologicals | Year: 2015

Objective: To optimize the procedure for culture of rabies virus (RV) in chick embryo cells. Methods: M199 was used as a basal medium, to which human serum albumin, fetal bovine serum and HEPES buffer were added respectively then sodium bicarbonate was added separately to prepare media Ml, M2 and M3. CTNCEC25 strain obtained by subculture of CTN-1 V strain was inoculated to chick embryo cell (CEC) suspension and cultured under various conditions. The ranges of four parameters, i.e. formula of medium, temperature for culture, MOI and time for culture, were determined by single factor test, of which the combination was optimized by orthogonal test. Results: The technological parameters determined by single factor test were as follows: M2 or M3 was used, and the culture temperature, MOI and culture time were 33 ∼ 36 °C, 0.01 ∼ 0.001 FFU/cell and 72 ∼ 120 h respectively. Under the condition, the CNTCEC25 strain reached a titer of more than 7.0 lgFFU/ml. The procedure optimized by orthogonal test was as follows: M3 was used, while the culture temperature, MOI and culture time were 33 °C, 0.01 FFU/cell and 120 h respectively, by which the vims titer reached 7.5 lgFFU/ml. Conclusion: The procedure for culture of RV in chick embryo cells was optimized, and the titer of cultured CTNCEC25 strain increased from 6.0 to more than 7.0 lgFFU/ml, which laid a foundation of obtaining an ideal antigen amount for vaccine production. Source

Zhou L.-Z.,Shenzhen Weiguang Biological Products Co. | Liu Y.-D.,Shenzhen Weiguang Biological Products Co. | Dai M.-L.,Shenzhen Weiguang Biological Products Co. | Rong W.-H.,Shenzhen Weiguang Biological Products Co. | And 3 more authors.
Chinese Journal of Biologicals | Year: 2015

Objective: To determine the titer of rabies virus by cell fluorescence focus unit (FFU) assay. Methods: Rabies virus was diluted, inoculated to BSR cells, cultured for 22 ∼ 24 h, and stained with FITC-labeled specific antibody against rabies vims to count the fluorescence foci in infected cells, based on which the virus titer was calculated. The titers of 14 batches of rabies virus were determined by median lethal dose (LD50) assay in suckling mice and the developed method respectively, and the relationship between the two methods was analyzed. The same virus sample was determined at 3 time points, 6 times for each, to verify the reproducibility of the method. Three virus samples at different titers were determined for 3 times at various time points by 2 staff separately to verify the intermediate precision of the method. The same virus sample was 2-fold serially diluted to 9 dilutions, each of which was tested for titer for 3 times to determine the linear range of the method. A total of 38 batches of rabies virus CTNCKC strain were determined for titer by the developed method. Results: The range of -LgLD50 values of 14 batches of rabies virus determined by LD50 assay in suckling mice was 4.20 ∼ 8.19, while the range of LgFFU by FFU assay was 3.76 ∼ 7.69. The -LgLD50 and LgFFU exhibited the same trends, which showed a significantly linear correlation (adjusted R2 = 96.1). The CVs of samples determined for 6 times at the same time point and for 3. times at various time points were less than 2.00%. However, the CVs of samples determined for 3 times at various time points by two staff were less than 8.00%, which showed no significant difference (P > 0.05). The sample concentration showed a good linear relationship to LgFFU, with an adjusted R2 value of 99.3%, of which the linear range was 2.26 ∼ 6.12. The mean LgFFU of 38 batches of CTNCEC strain was 3.63-7.69, with a standard deviation (SI)) of 0.021∼0.57 and a CV value of less than 10.00%. Conclusion: The developed FFU assay showed high accuracy, reproducibility and intermediate precision, which might be used for the determination of rabies vims titer. Source

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