Preparation of mouse anti-human B7-2 monoclonal antibody and analysis of its role in inducing Fas and FasL on the surface of 8266 cells / 中华微生物学和免疫学杂志

Objective To prepare a mouse anti-human B7-2 monoclonal antibody ( McAb) and to study its effect on the induction of death-related molecules on the surface of tumor cells. -ethods Trans-genic cells, L929-B7-2, were used as the immunogen to immunize BALB/c mice. Through cell fusion, mul-tiple screening by immunofluorescence labeling and continuous subcloning, the hybridoma secreting B7-2 McAb was obtained. Biological characteristics of the McAb were analyzed using Ig subclass identification test strip, antigenic site competition inhibition assay and specific cell membrane molecules binding test. McAb was prepared through inducing ascites in vivo and then purified by protein G affinity chromatography. The purified McAb was co-cultured with 8266 cells, naturally expressing B7-2 molecules, to observe the expres-sion of Fas and FasL on cell surface by flow cytometry ( FCM) . Results The prepared B7-2 McAb labeled as 12G4 was successfully obtained with a titer of 0. 1 μg/5×105 cells. Its heavy and light chains were IgG2b and κ, respectively. The concentration of the purified ascites-derived antibody was 1. 61 mg/ml. FCM re-sults showed that the 12G4 McAb recognized cell membrane molecules well with a positive binding rate of 89. 6％ to 8266 cells. The mean value of the Fas molecule on the cell surface increased after incubating with 20 μg/ml of 12G4 McAb for 12 h and reached the peak of 62575. 8 at 48 h, which was significantly higher than the maximum value of 57135. 4 in the IgG control group (P<0. 05). After culturing the cells with 20μg/ml of 12G4 McAb for 12 h, the expression of FasL on the cell surface also increased and reached the maximum of 7. 98％ at 48 h, which was significantly higher than the 1. 10％ in the IgG control group ( P<0. 05). Conclusions B7-2 McAb was successfully prepared. It could be used to induce the expression of some death-related molecules on the surface of tumor cells.

Mesenchymal stem cells promote articular cartilage repair and regeneration / 中国组织工程研究

BACKGROUND:After articular cartilage injury, the injured cartilage almost has no self-healing ability. Articular cartilage injury repair has been always a difficulty in clinical work. OBJECTIVE:To explore the types and biological characteristics of stem cels for articular cartilage repair and to ensure the role and relative merits of stem cel transplantation in articular cartilage repair. METHODS:PubMed and CNKI were retrieved by the first author for relevant articles published from 1998 to 2015 using the keywords of “articular cartilage injury, mesenchymal stem cels, regeneration” in English and Chinese, respectively. Finaly, 47 articles were included in result analysis. RESULTS AND CONCLUSION: Stem cel therapy is the most effective method for repair of articular cartilage injury. Mesenchymal stem cels from bone marrow, adipose and umbilical cord have strong chondrogenic and cloning capacities. Bone marrow mesenchymal stem cels have a stronger differentiation potential, and can be used for repair of cartilage injury. Umbilical cord-derived mesenchymal stem cels have a low tumorigenicity. Adipose-derived stem cels can proliferate and grow faster. Stem cels combined with natural carrier materials, such as colagen, gelatin, fibrin and alginate, can promote cel adhesion, differentiation and proliferation, in order to build an effective tissue engineered cartilage for repair of articular cartilage defects.

Chemical constituents from stems and leaves of Micromelum integerrimum / 药学学报

A new benzene derivative microintegerrin C (1) and a new norsesquiterpenoid microintegerrin D (2), along with six known compounds (3-8), were isolated and identified from stems and leaves of Micromelum integerrimum by various chromatographies such as silica gel, Sephadex LH-20, RP-18 column chromatography and HPLC. Their structures were mainly identified based on the spectral data analysis such as 1D-, 2D-NMR and HR-EI-MS. All known compounds were isolated from this plant for the first time.

Immune intervention effect of human-mouse chimeric antibody B7-1 against murine lupus nephritis model / 中国免疫学杂志

Objective:On the basis of the use of chemical methods to establish mouse model of lupus nephritis and its biological identification , we investigate the reverse effect of pathological lesions of B 7-1 human-mouse chimeric antibody blockade against B7/D28 signaling pathway in mice with lupus nephritis model.Methods:Pristane was injected intraperitoneally to 6-week-old female C57BL/6J mice at dose of 0.5 ml per mouse in one go,and urine protein,ANA and renal pathological changes were detected on a monthly basis.Mice whose urine protein content reached ++and ANA fluorescence intensity reached ++were randomly devided into three groups ,five each.Antibody intervention group was sequentially injected with B 7-1-mouse chimeric antibody by orbital venous , positive control group was injected with immunosuppressant CTX , negative control group was injected with isotype control IgG.Urine protein and ANA were also detected on a monthly basis.Mice were sacrificed three months after intervention was executed.Kidney was used for H&E dying , IC detection and electric microscope observation.Results: After four-month Pristane induction , urine protein content of 80%mice reached +-+++,meanwhile,serum ANA fluorescence intensity reached ++-+++.Glomerulonephritis infiltrating cells were observed Mice with urine protein and ANA , glomerular inflammatory cell infiltration , tubular epithelial cell degeneration visible edema ,vascular congestion significantly ,fibrosis.After antibody intervention ,urine protein content in antibody intervention group gradually reduced from ++-+++to ±-+++,ANA ++-+++to +-++,and were significantly different from that in the negative control group ( P<0.01 ).Analysis of kidney H&E dying showed that antibody glomerular infiltration of inflammatory cells in the intervention group and tubular congestion and other symptoms were improved significantly.Immunofluorescence staining indicated that fluorescence intensity of IC was significantly reduced in the antibody intervention group.Electron dense deposits reduction and glomerular basement membrane uniformity were observed in antibody intervention group by electric microscope when compared with the negative control group.Conclusion:B7-1 antibodies could downregulate immune response through inhibiting B 7-1/CD28 signaling pathway , reducing the production of autoantibodies and reversing pathological damage caused by autoimmune response .

Improved lipid productivity of Nannochloropsis by heavy-ion irradiation mutagenesis / 生物工程学报

Nannochloropsis has been considered as a promising feedstock for biodiesel production in recent years. To improve its lipid productivity, heavy-ion irradiation mutagenesis, an effectively breeding method used in plants and microorganisms was applied in Nannochloropsis oceanica OZ-1. After large-scale screening using Imaging-PAM and microplate-reader, two mutants (HP-1 and HP-2) with higher growth rate were isolated from the wild type N. oceanica. Subsequently analysis showed that after 18 days of cultivation biomass accumulation of the HP-1 and HP-2 mutant was increased by 18% and 26% respectively compare to the wild type. Total lipid productivity of the HP-1 and HP-2 mutant was 295 mg/(L x d) and 275 mg/(L x d), respectively, whereas that of the wild type was 247 mg/(L x d). Both mutants showed significantly advantage over their wild type concerning biomass accumulation and lipid productivity.