Expression of the S glycoprotein of transmissible gastroenteritis virus (TGEV) in transgenic potato and its immunogenicity in mice / 대한수의학회지

Transgenic plants have been tested as an alternative host for the production and delivery of experimental oral vaccines. Here, we developed transgenic potatoes that express the major antigenic sites A and D of the glycoprotein S from transmissible gastroenteritis coronavirus (TGEV-S0.7) under three expression vector systems. The DNA integration and mRNA expression level of the TGEV-S0.7 gene were confirmed in transgenic plants by PCR and northern blot analysis. Antigen protein expression in transgenic potato was determined by western blot analysis. Enzyme-linked immunosorbent assay results revealed that based on a dilution series of Escherichia coli-derived antigen, the transgenic line P-2 had TGEV-S0.7 protein at levels that were 0.015% of total soluble proteins. We then examined the immunogenicity of potato-derived TGEV-S0.7 antigen in mice. Compared with the wild-type potato treated group and synthetic antigen treated group, mice treated with the potato-derived antigen showed significantly higher levels of immunoglobulin (Ig) G and IgA responses.

Generation of transgenic corn-derived Actinobacillus pleuropneumoniae ApxIIA fused with the cholera toxin B subunit as a vaccine candidate

Corn, one of the most important forage crops worldwide, has proven to be a useful expression vehicle due to the availability of established transformation procedures for this well-studied plant. The exotoxin Apx, a major virulence factor, is recognized as a common antigen of Actinobacillus (A.) pleuropneumoniae, the causative agent of porcine pleuropneumonia. In this study, a cholera toxin B (CTB)-ApxIIA#5 fusion protein and full-size ApxIIA expressed in corn seed, as a subunit vaccine candidate, were observed to induce Apx-specific immune responses in mice. These results suggest that transgenic corn-derived ApxIIA and CTB-ApxIIA#5 proteins are potential vaccine candidates against A. pleuropneumoniae infection.

Dynamic observation on splenocytes subsets in mice immunized with the transgenic alfalfa vaccine containing Eg95-EgA31 fusion gene of Echinococcus granulosus / 中国人兽共患病学报

To observe changes on subsets of splenocytes in mice immunized with the transgenic alfalfa (Medicago sativa) vaccine containing Eg95-EgA31 fusion gene of Echinococcus granulosus dynamically,the leaf protein was extracted from the transgenic alfalfa by heat-coagulation method and prepared for a solution with a concentration of 20 g/ L.The 132 BALB/c mice were divided into 3 groups randomly and immunized intranasally or orally with the leaf protein solution once per 3 days for 2 months.At the same time,the group of intranasal immunization with leaf protein from the non-transgenic alfalfa was set as control group.4 mice randomized from each group were killed to get the spleens at Week 0,2,4,6,8,10,12,14,16,18 and 20 after last immunization,and the splenocytes were separated to measure CD_4~+and CD_8~+T cell subsets by FCM.In the oral group,CD_4~+subset increased significantly from Week 6 to Week 10 after the last immunization and reached the peak at Week 6.While CD+ 8 subset increased obviously from Week 4 to Week 12 and reached the highest level at Week 8.In the intranasal group,the significant increase of the CD_4~+subset was observed from Week 4 to Week 6 and also reached the peak at Week 6.The similar trend of CD_8~+ subset was observed from Week 4 to Week 10 and reached the highest level at Week 8.It was suggested that CD+ 4and CD+ 8subsets played an important role in the protection induced in mice immunized with the transgenic alfalfa vaccine.

Progresses on Biosynthesis of Long Chain Polyunsaturated Fatty Acids in Plant / 中国生物工程杂志

There is immense interest in the long-chain polyunsaturated fatty acids(LC-PUFAs) on account of their health-beneficial properties.There has been considerable interest in the production of LC-PUFAs in transgenic plants to provide a cheap,sustainable and clean source of these fatty acids.Several main LC-PUFAs,their roles and metabolic pathway in plant are introducedbriefly,progresses on biosynthesis of LC-PUFAs in transgenic plant are reviewed,and strategies for improving the yields of LC-PUFAs in plant are also discussed.

Research Progress of Taking Key Enzyme in Metabolism as Selectable Marker in Transgenic Plant / 中国生物工程杂志

In plant genetic engineering, selectable marker is needed to distinguish transformant. As the commercialization of transgenic plants, people are more and more paying close attention to their safety, among which mainly refers to the safety of selectable marker. In order to increase the safety of transgenic plants, biologists began to search for biosafe selectable marker.Current research progress of taking key enzyme in metabolic pathways were overviewed,which include glycometabolism, amino acid metabolism, hormone metabolism ,nucleotide metabolism and protein metabolism et cetera, as selectable marker in transgenic plants.

The Effect of Transgenic Plants on Rhizosphric Soil Ecosystems / 中国生物工程杂志

Along with the transgenic plant planting more and more popular in the world,the influence of transgenic plants on ecological environment was widely given attention and the comprehensive research had been done on effect of transgenic plants in soil ecosystems.The latent risks of transgenic plants to the soil ecosystem were reviewed.Also,the study on decomposition of transgenic plants in soil,the vertical and horizontal transfer possibility of recombinant DNA by transformation,as well as the influence of the exogenous gene and its expression product on soil animals,soil microbes as well as soil physical and chemical properties were also discussed,all of which would provide useful information for utilization of transgenic plants more safely in future.