Bovine viral diarrhea virus Erns protein expressed in Chinese hamster ovary cells and its immunogenicity analysis / 生物工程学报

The aim of this study was to produce Erns protein of bovine viral diarrhea virus (BVDV) by using suspensively cultured CHO cells expression system and to analyze the immunogenicity of the purified Erns protein. In this study, the recombinant eukaryotic expression plasmid pcDNA3.1-BVDV-Erns was constructed based on the gene sequence of BVDV-1 NADL strain. The Erns protein was secreted and expressed in cells supernatant after transfecting the recombinant expression plasmid pcDNA3.1-BVDV-Erns into CHO cells. The expression and purification of the Erns protein was analyzed by SDS-PAGE, the reactivity was determined with anti-His monoclonal antibodies and BVDV positive serum with Western blotting. Immunogenicity analysis of the Erns protein was determined after immunizing New Zealand white rabbits, and the serum antibodies were tested by indirect ELISA (iELISA) and indirect immunofluorescence (IFA). The serum neutralizing titer of the immunized rabbits was determined by virus neutralization test. The concentration of the purified Erns protein was up to 0.886 mg/mL by BCA protein quantification kit. The results showed that the Erns protein could be detected with anti-His monoclonal antibodies and anti-BVDV sera. Serum antibodies could be detected by iELISA on the 7th day post-prime immunization, and the antibody level was maintained at a high titer until the 28th day post-immunization. The antibody titer was 1:128 000. Furthermore, the expression of the Erns protein in BVDV-infected MDBK cells could be detected with immunized rabbits sera by IFA. Moreover, antigen-specific neutralizing antibodies of 2.71 log10 was induced in rabbits. In this study, purified BVDV Erns protein was successfully produced using CHO suspension culture system, and the recombinant protein was proved to have a good immunogenicity, which may facilitate the development of BVD diagnosis method and novel subunit vaccine.

Recombinant porcine interferon-gamma expressed in CHO cells and its antiviral activity / 生物工程学报

The aim of this study was to produce recombinant porcine interferon gamma (rPoIFN-γ) by Chinese hamster ovarian (CHO) cells expression system and to analyze its antiviral activity. Firstly, we constructed the recombinant eukaryotic expression plasmid pcDNA3.1-PoIFN-γ and transfected into suspension cultured CHO cells for secretory expression of rPoIFN-γ. The rPoIFN-γ was purified by affinity chromatography and identified with SDS-PAGE and Western blotting. Subsequently, the cytotoxicity of rPoIFN-γ was analyzed by CCK-8 test, and the antiviral activity of rPoIFN-γ was evaluated using standard procedures in VSV/PK-15 (virus/cell) test system. Finally the anti-Seneca virus A (SVA) of rPoIFN-γ activity and the induction of interferon-stimulated genes (ISGs) and cytokines were also analyzed. The results showed that rPoIFN-γ could successfully expressed in the supernatant of CHO cells. CCK-8 assays indicated that rPoIFN-γ did not show cytotoxicity on IBRS-2 cells. The biological activity of rPoIFN-γ was 5.59×107 U/mg in VSV/PK-15 system. Moreover, rPoIFN-γ could induced the expression of ISGs and cytokines, and significantly inhibited the replication of SVA. In conclusion, the high activity of rPoIFN-γ was successfully prepared by CHO cells expression system, which showed strong antiviral activity on SVA. This study may facilitate the investigation of rPoIFN-γ function and the development of novel genetically engineered antiviral drugs.

Generation and immunogenicity evaluation of Senecavirus A virus-like particles / 生物工程学报

To develop Senecavirus A (SVA) virus-like particles (VLPs), a recombinant prokaryotic expression plasmid pET28a-SVA-VP031 was constructed to co-express SVA structural proteins VP0, VP3 and VP1, according to the genomic sequence of the field isolate CH-FJ-2017 after the recombinant proteins were expressed in E .coli system, and purified by Ni+ ion chromatographic method. The SVA VLPs self-assemble with a high yield in vitro buffer. A typical VLPs with an average diameter of 25-30 nm which is similar to native virions by using TEM detection. Animals immunized by SVA VLPs shown that the VLPs induced high titers neutralizing antibodies in Guinea pigs. This study indicated that the VLPs produced with co-expressing SVA structural proteins VP0, VP3 and VP1 in prokaryotic system is a promising candidate and laid an important foundation for the development of a novel SVA VLPs vaccine.

Aquaporin 8 expression in human placenta and fetal membrane / 中国组织工程研究

BACKGROUND: Placenta and fetal membrane play an important role In maternal-fetal homeostasis. However, the molecular and cellular mechanisms underlying water transfer across placenta and amniotic membrane remain unknown. It is hypothesized that maternal-fetal fluid exchanges via aquaporin (AQP) water channels in the placenta and fetal membrane.OBJECTIVE: To investigate AQP8 protein expression in normal human placenta and fetal membrane.DESIGN, TIME AND SETTING: A control observation was performed at the Central Laboratory of Guangzhou Medical College from July to December 2005.MATERIALS: Human placenta and fetal membrane tissues from 5 elective cesarean section deliveries of normal term pregnancies (range 37-42 weeks) were studied. Maternal age averaged (27?) years old. Experimental protocol was approved by the Hospital's Ethics Committee.METHODS: Thirty minutes after delivery, fetal membrane and placenta were dissected and washed with sterile physiological saline. Some were frozen at -80?, and the remaining tissues were fixed for 24-48 hours with 10% neutral formalin and paraffin embedded for immunohistochemical staining.MAIN OUTCOME MEASURES: AQP8 expression and distribution in human placenta and fetal membrane were detected by the reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry, and Western blotting analysis.RESULTS: RT-PCR results showed that AQP8 mRNA was expressed in both placenta and fetal membrane tissues. Western blotting analysis also yielded positive results in placenta and fetal membrane with a specific band site at approximately 45 000.Immunohistochemistry results revealed that AQP8 protein was expressed in placental syncytiotrophoblasts, amniotic epithelial cells, and chorion cytotrophoblasts.CONCLUSION: At protein level, AQP8 is expressed in placental syncytiotrophoblasts, amniotic epithelial cells, and chorion cytotrophoblasts.

Expression of aquaporin-1,3,8,9 mRNA in human amniotic membranes in polyhydranmios / 中华围产医学杂志

Objective To determine the expression of aquaporin-1,3,8,9 mRNA (AQP-1,3,8, 9) in amniotic membranes in pregnant women with polyhydramnios. Methods Amniotic membranes were collected from women who presented with either polyhydramnios (n= 5)or normal amniotic fluid volume (control, n= 5) underwent elective cesarean sections at term. The AQP-1,3,8,9 mRNA expression were detected by reverse transcriptase-polymerase chain reaction (RT-PCR). Results The expression of AQP-9 mRNA on fetal membranes were significantly higher in polyhydramnios groups (1. 1403±0. 0831) than that of control (0. 5903±0. 1909) (P = 0. 002), although the expression of AQP-1, 3 and 8 showed no significant difference between the two groups (P= 0. 972, 0. 242,0. 608, respectively). Conclusions AQP-9 may play an important role in maintaining the volume and the balance of different components of amniotic fluid in polyhydramnios cases.