Isolation, culture and identification of goat alveolar macrophages / 中国比较医学杂志

Objective In order to study the biological characteristics of macrophages and provide the materials to study the survival mechanism of intracellular parasites, we conducted this study to establish a high-purity alveolar macrophage isolation and culture method.Methods Goat lungs were lavaged with normal saline in sterile environment several times, and cells were collected and then goat alveolar macrophages were purified by density gradient centrifugation using peripheral blood mononuclear cells (PBMC) solution.The isolated goat alveolar macrophages were cultured in cell culture medium containing 10% fetal bovine serum and cell morphology was observed under an inverted microscope every day,and the phagocytic activity of the cells was detected by chicken red blood cell phagocytosis test.Flow cytometry was used to detect CD14, a characteristic monocyte-macrophage surface marker.Results The adherent cells were characterized by typical macrophage morphology, pseudopodia and protrusions, showing round and irregular shape, rich cytoplasm, and large cell body.Of the cultured macrophages, 54.5% could phagocytize chicken erythrocytes and showed good phagocytic activity.After one month of in vitro culture, 93.7% of the cells were able to express CD14 antigen, which had a macrophage-specific immunophenotype.Conclusions The alveolar macrophages obtained in this study have high purity and good bioactivity, thus provide a cell model for studying the immune mechanism of intracellular parasites.

Experimental study on bacteriostatic effect of recombinant human lactoferrin on Helicobacter pylori / 重庆医学

Objective To evaluate the bacteriostatic effect of recombinant human lactoferrin(rhLF) on Helicobacter(H .) py‐lori and its influence on CagA ,Ure and gastric mucosal IL‐8 .Methods The minimum inhibitory concentration(MIC)and the influ‐ence of different drug concentrations on the proliferation of H .pylori were detected .The effects of rhLF on the mRNA and protein expressions of CagA and Ure in H .pylori were detected by RT‐PCR and Western blot ,respectively .The animal study :Balb/c mice were adopted and assigned randomly into four groups ,including the standard triple+rhLF(group A) ,rhLF(group B) ,standard tri‐ple(group C) and normal saline(group D) .The histopathological HE staining was used to observe the gastric inflammation and ELISA was used to detect the IL‐8 level of gastric tissue in each group .Results MIC was 0 .5 mg/mL ,moreover rhLF inhibited the bacterial growth and proliferation with a concentration‐dependent manner .rhLF could reduce the expression of H .pylori major viru‐lence factor CagA ,mRNA and protein of Ure .Comparing the group A with the group B ,C and D ,the gastric mucosal inflammation score and the IL‐8 levels of gastric tissue homogenates had statistically significant differences(P<0 .05) .Conclusion rhLF inhibits the growth and proliferation of H .pylori ,moreover inhibit the expression of major virulence factor CagA in H .pylori ,mRNA and protein of Ure in different degrees ,weakens its pathogenicity ,meanwhile reduces the IL‐8 level in mice gastric mucosa ,and allevi‐ates H .pylori related gastric mucosal inflammatory response .

Deletion of marker gene in transgenic goat by Cre/LoxP system / 生物工程学报

In producing transgenic livestock, selectable marker genes (SMGs) are usually used to screen transgenic cells from numerous normal cells. That results in SMGs integrating into the genome and transmitting to offspring. In fact, SMGs could dramatically affect gene regulation at integration sites and also make the safety evaluation of transgenic animals complicated. In order to determine the deletion time and methods in the process of producing transgenic goats, the feasibility of deleting SMGs was explored by Cre/LoxP before or after somatic cell cloning. In addition, we compared the efficiency of protein transduction with plasmids co-transduction. We could delete 43.9% SMGs after screening out the transgenic cell clones, but these cells could not be applied to somatic cells cloning because of serious aging after two gene modifications. The SMG-free cells suitable for nuclear transfer were accessible by using the cells of transgenic goats, but this approach was more time consuming. Finally, we found that the Cre plasmid could delete SMGs with an efficiency of 7.81%, but about 30% in SMG-free cells had sequences of Cre plasmid. Compared with Cre plasmid, the integration of new exogenous gene could be avoided by TAT-CRE protein transduction, and the deletion rate of TAT-CRE transduction was between 43.9 and 72.8%. Therefore, TAT-Cre transduction could be an effective method for deleting selectable marker genes.

Cloning and expression of a single human immunoglobulin heavy-chain variable domain with vascular endothelial growth factor binding activity / 生物工程学报

In the application of therapeutic antibodies, large molecular weight of antibodies is always a problem that prevents them from penetrating into tissues or binding to antigenic determinants. To overcome this problem, we investigated the function of the heavy chain variable domain of a monoclonal anti-VEGF human IgM antibody derived from the Five-Feature Translocus Mice. We cloned the cDNA of the heavy chain variable domain, which was then inserted into pET28a vector and expressed in Escherichia coli. After purification and renaturation of the denatured recombinant protein, we obtained a 16 kDa antibody fragment, which is named as rhVVH. By immunoassaying its VEGF-binding capability in vitro, we proved that rhVVH retains this activity as the complete IgM. Importantly, rhVVH is shown to inhibit the HUVEC cell proliferation in a concentration-dependent manner. Our results indicate that the single heavy chain variable domain might inherit part of the biological function of the complete IgM antibody, which provided a valuable potential in further research on antibody miniaturisation.

Generation of fully human anti-vascular endothelial growth factor 165 monoclonal antibody with antitumor efficacy from transgenic five-feature mice / 中国药科大学学报

Aim: To prepare a fully human anti-VEGF_(165)(vascular endothelial growth factor 165) monoclonal antibody with antitumor activity from five-feature mice which express human immunoglobin loci. Methods: A routine method for the generation of monoclonal antibodies( mAbs) against the human VEGF_(165) was developed. The immunizing effect between five-feature mice and BALB/c was observed and the mAb was purified through MBP IgM affinity chromatography. The effect of mAbs on antitumor was tested ire vitro by T24 cell line. Results: Four hybri-domata secreting mAbs steadily were isolated successfully, and the serum titer of mAb in BALB/c mice was almost 10 times higher than that in five-feature mice. The indirect ELISA method for mAb titer determination was also established. The anti-VEGF_(165) mAb was purified to homogeneity by precipitation with ammonium sulfate followed by the affinity chromatography on MBP IgM purification column. Moreover, both purified human IgM V_2, V_(75) and mouse ascites were characterized by SDS-PAGE and Western blotting. Proliferation of T24 cell line was considerably inhibited by V_2 and V_(75). Conclusion: Five-feature mice could be used to produce fully human monoclonal antibody. The fully human anti-VEGF mAb is potential in the cancer treatment.

Expression and analysis of the recombinant human interleukin-21 (rhIL-21) in Pichia pastoris / 生物工程学报

Interleukin-21 is a type I cytokine mainly produced by activated CD4+ T cells that acts as a regulator of immune system. In this work, hIL-21cDNA was amplified from human peripheral blood lymphocytes by RT-PCR, and then inserted into pPIC9K. The recombinant vector pPIC9K-hIL21cDNA was linearized by Sac I, and transformed into Pichia pastoris strain GS115 by electroporation. Transformants were selected by G418 and confirmed by PCR. The recombinant protein was expressed and secreted into the supernatant after inducing by methanol. SDS-PAGE analysis indicated the molecular weight of rhIL-21 was about 16 kD. ELISA results show that the yield of rhIL-21 reach 229.28 mg/L, rhIL-21 was purified from culture supernatants, and it was purified to about 95% purity with ion-exchange chromatography. When co-stimulate with Con A, rhIL-21 can promote the proliferation of human lymphocytes. This is the first expression of bio-active rhIL-21 in Pichia pastoris. It lays a foundation for further research in immunotherapy and cancer therapy.

Goat MII ooplasts support preimplantation development of embryos cloned from other species / 生物工程学报

The preimplantation development competences of somatic cell nuclear transfer (SCNT) embryos reconstructed with enuleated goat (Capra hircus) Metaphase II (MII) oocytes matured in vivo and whole cells derived from adult fibroblasts of several mammalian species (goat, boer goat, bovine, tahr, panda) and human patient were evaluated. Results obtained from our experiments revealed that these reconstructed SCNT embryos could complete preimplantation development to form blastocysts. The fusion rate and blastocyst rate of intra-species SCNT embryos (Capra hircus as control) was 78.67 (557/708); 56.29% (264/469), that of sub-species or inter-species SCNT embryos were: boer goat 78.18% (541/692); 33.90% (40/118), bovine 70.53% (146/207); 22.52% (25/111), tahr 53.51% (61/114); 5.26% (3/570), panda 79.82% (1159/1452); 8.35% (75/898) and human 68.76% (317/461); 5.41% (16/296), respectively. It is concluded that (1) there are no relationships between fusion rate and relativeness of the recipient cytoplasm to nucleus donor cells, (2) cytoplast of the goat MII oocyte can support the preimplantation development of SCNT embryos reconstructed with nucleus from other species, (3) the blastocyst rate of close relative inter-species SCNT embryos is higher than that of distant relative inter-species SCNT embryos.

Targeting Prnp in bovine fibroblasts by promoter-trap strategy / 生物工程学报

Promoter-trap strategy for enriching targeted colonies has been usually used to elevate the gene targeting efficiency in somatic cells. Knocking out Prnp in animals by gene targeting can render them resistant to Prion diseases. We constructed a bovine Prnp promoter-less targeting vector BoPrPneo, then transfected the linearized vector into the bovine fetal fibroblasts BFF through electroporation. After selecting in cell culture medium with 250 microg/mL G418, we obtained 99 drug-resistant cell colonies, 4 of them were positive for targeted events after PCR screening, and the targeted colonies were further confirmed by sequencing and Southern blotting. This suggests that one allele of Prnp has been successfully knocked out in bovine fetal fibroblasts. This research supplies a simple, safe and effective method to targeting bovine Prnp.

Effects of Xiezhuo Jiedu Decoction on expression of IL-10,TNF-?and NF-?B in ulcerative colitis rats / 中华中医药杂志

Objective:To observe the effects and mechanism of Xiezhuo Jiedu Decoction on the expression of IL-10,TNF-? and NF-?B in ulcerative colitis rat.Methods:2,4,6-trinitrobenzene sulfonic acid(TNBS)/ethanol solution was administrated by enema to establish ulcerative colitis rats models.Five groups were set up in the experiments:normal control group,model control group,salazosulfamide group,Xiezhuo Jiedu Decoction low-dose group,Xiezhuo Jiedu Decoction high-dose group;Pathomorphological observation was carried out on the rats'colon(DAI scores and CMDI scores).Cytokines IL-10,TNF-? were determined by radioimmunoassay;NF-?B p65 was determined by immunohistochemical staining(SP method).Results:Xiezhuo Jiedu Decoction can significantly reduce the CMDI sores of the rats'colon and the expression of NF-?B p65,increase the content of IL-10,decrease the content of TNF-?.Conclusion:Xiezhuo Jiedu Decoction had good therapeutic effect on ulcerative colitis in rats,its mechanism may be related to reducing the expression of NF-?B p65,increasing the content of IL-10,decreasing the content of TNF-?.

Development of Acute Promyelocytic Leukemia in PML-RARalpha Transgenic Mice / 中国实验血液学杂志

To investigate the leukemogenic potential of PML-RARalpha fusion protein in vivo, hCG-PML-RARalpha transgene was constructed using molecular cloning technique and hCG-PML-RARalpha transgenic mice were generated. The genotype and phenotype of hCG-PML-RARalpha transgenic mice were analyzed by PCR, RT-PCR, morphology of peripheral blood and bone marrow cells, and pathological examination of spleen, liver and bone marrow. As a result, acute promyelocytic leukemia was developed in 3 hCG-PML-RARalpha transgenic mice in 1 - 5 months. The results demonstrated that PML-RARalpha fusion protein plays a crucial role in leukemogenesis.

Establishment of double reporter transgenic mice for monitoring Cre recombinase activity / 第三军医大学学报

Objective To establish a double reporter transgenic mice for monitoring Cre recombinase activity. Methods ZAP DNA fragment with lacZ and human alkaline phosphatase (hAP) gene was microinjected into the male pronucleus of 554 fertilized eggs from C57BL/6 mice. The founder mice and their progeny were screened for integration of transgene into the mouse genome by PCR and Southern blotting. The expression of lacZ transgene at early embryos from F1 generation mice was analyzed by X gal staining. Results A total of 398 survival ZAP DNA injected fertilized eggs were transfered to the oviducts of 21 pseudopregnant recipient mice. Of the 21 recipient mice, 13 became pregnancy and gave birth to 68 offspring mice. The zygote survival rate and birth rate were 71% (398/554) and 17% (68/398), respectively. Of the 68 offspring mice, 9 mice (5 males and 4 females) were identified by PCR and Southern blot analysis. Total integration rate and efficiency of transgene was 13% (9/68) and 1.6% (9/554), respectively. Nine mice as the founders were back crossed to set up F1 generation with other inbred C57BL/6 mice. Out of 9 transgenic mice, transmission of reporter gene in F1 offspring mice followed Mendelian rules, but the expression of lacZ protein was detected at the early embryonic stage (13.5 days postcoitum) in only 3 mice. Conclusion A double reporter transgenic mice for monitoring Cre recombinase activity is established.