Tumor cell-specific gene transfer with retroviral vectors displaying single-chain antibody / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To specifically deliver the therapeutic gene to cancer cells and construct target retroviral vectors by inserting the single-chain variable antibody fragment into the retroviral envelope.</p><p><b>METHODS</b>Single-chain antibody expression vector pET -20bScfv was constructed. Binding activity of the genetically engineered single-chain variable antibody fragment was verified by enzyme-linked immunosorbent assay (ELISA) and Western blot. At the same time, by means of polymerase chain reaction (PCR)-directed mutagenesis, the appropriate cloning site EcoT22/Sal was generated at the N-terminus of receptor-binding SU domain in the MoMLV env polypeptide. Then the single- chain antibody gene, encoding a functional antibody, was inserted into the cloning site. The Scfv-env fusion gene fragment was subcloned into CMV expression vector. The Lac-Z retrovirus that co-displayed the Scfv-env chimeric protein and wild-type env protein was produced by transfection of Psi 2 cells with retroviral plasmid and the fusion gene expressing plasmid. To confirm the specificity of the recombinant retrovirus, infection assays and competitive inhibition assays were performed.</p><p><b>RESULTS</b>The results of ELISA and Western blot showed that the genetically engineered single-chain variable antibody fragment could bind to the SHG44 cells surface membrane antigen. Virus-binding assay, viral infection and competitive inhibition assays confirmed that the harvested virus efficiently bound to and infected SHG44 cancer cells expressing the relative membrane antigen specially via the recognition of the target antigen.</p><p><b>CONCLUSION</b>These results imply that insertion of Scfv into the retroviral envelope can specifically deliver the interested gene into specific antigen-producing cancer cells.</p>

Investigation of Dust Mites in Dormitories, Classrooms and Library of a College / 环境与健康杂志

0.05), in the sheets, quilt covers, bedsides, coats and underwear, the difference was significant (P

Paragonimus skrjabini Infection in Animal Reservoir Hosts and Questionnairing in Residents at a Village of Hubei Province / 中国寄生虫学与寄生虫病杂志

Freshwater crabs (Sinopotamon denticulatum) were examined for metacercariae. Cats and dogs were also examined for Paragonimus infection. Questionnairing was carried out on health knowledge and behaviors among local residents in a village of Baokang County, Hubei Province. Results showed that the infection rate of Paragonimus skrjabini metacercariae in Sinopotamon denticulatum was 20.5% (46/214), with 15.6% (20/128) in a mining area and 30.2%(26/86) for the non-mining area respectively ( ?2=6.5, P0.05). Questionnairing showed that dogs and cats were with the habit of foraging and defecating at streams and children had the habits of eating raw or under-cooked crabs. The natural and ecological environments are in favor of the life cycle of P. skrjabini.