ABSTRACT
Objective To explore the biological functions of E77.43, a gene segment of Microtus fortis, in treating Schistoso-ma japonicum infection. Methods Recombinant retroviral vectors of pRevTRE-E77.43 was constructed, and recombinant retro-viral vectors were transfected into PA317 cells, and the stable cell lines were obtained by hygromycin screening, followed by the packaging, concentration and purification of recombinant retrovirus. The virus was transferred to the mice infected by S. japoni-cum via intravenous or intraperitoneal injection, through which the express of target gene and the treatment function in vivo were observed. Results The experiment showed the recombinant virus injected mice could efficiently express E77.43 on the 7th day after the injection which lasted for forty-five days thereafter. A significant reduction in adult worms (31.0％) and a high reduction (35.0％) in liver eggs were induced by pRevTRE-E77.43, while the reduction in adult worms and that in liver eggs was 1.2％and 0.9％induced by pRevTRE respectively (t=3.524, 9.485, both P<0.01). Conclusion pRevTRE-E77.43 could be used for the treatment of S. japonicum infection, indicating that E77.43 may involve in the natural resistance of M. fortis to S. japonicum infec-tion.
ABSTRACT
Objective To develop neural stem cells(NSCs) which can stably express exogenous brain-derived neurotrophic factor(BDNF) in vitro. Methods NSCs from the subependymal zone of embry-onic day 14.5(E14.5) rat brain were purified by limiting dilution assay and then infected with supernatant of recombinant retrovirus pLXSN-BDNF and retrovirus pLXSN. The original copy numbers of exogenous gene templates from three groups NSCs(pLXSN-BDNF viral infection group, pLXSN viral infection group, control group) were detected by fluorescent quantitative PCR(FQ-PCR). ELISA assay was used for determining the protein contents of BDNF of supernatant from three groups NSCs for six days continually after seeded in 24-well plates in the same cell density. Results NSCs were purified successfully by limiting dilution assay.The original copy numbers of exogenous BDNF gene templates from pLXSN-BDNF viral infection group by FQ-PCR were (19.57±0.65) × 10~3 copies/μl, higher than those of another two groups(P < 0.05). The protein contents of BDNF of supernatant from NSCs of pLXSN-BDNF viral infection group was highest among three groups and compared with another two groups had statistical significance (P <0.05) . Conclusion The purified NSCs can be transduced exogenous BDNF successfully with supematant of recombinant retrovir-us pLXSN-BDNF which provide experimental evidences and laying foundations for further research of retinal transplantation and quantization investigation of gene therapy for optic nerve injury.
ABSTRACT
Objective To explore whether the neural stem cells(NSCs) can act directly as a gene target cell which can be infected by the recombinant retrovirus and express the products of exogenous genes after infection. Methods The NSCs were cultured with supernatant containing the recombinant retroviruses with the genes of NGF or GDNF for two days.After screened with G418,the infected NSC were expanded at the present of bFGF in culture.The PC12 cells and the neurons of ventral midbrain of rat were cultured by the medium from the infected NSC,which were called as GDNF\|containing conditioned medium NGF or GDNF\|containing conditioned medium the morphological changes of the dopamine neurons of the ventral midbrain and expression of exogenous genes of the infected NSCs were detected by immunohistochemistry staining. Results It was estimated that about fifty percent of NSCs via retrovirus\|mediated NGF or GDNF gene transduction were G418\|resistant.These infected NSCs began to differentiate.Long and radical processes reached out from the sphere of proliferation and the cells migrated towards outside along the processes.The NSC infected with gene of NGF showed an astroid\|shape with larger body and processes.The NSC infected with gene of GDNF showed a shuttle\|shape with a smaller body and long processes.The PC12 cells increased in the NGF\|containing conditioned medium and stretched out long neurites.The dopamine neuron of the ventral midbrain which were immunoreactive for TH also showed a larger body and longer processes in the GDNF\|containing conditioned medium.Most of G418\|resistant NSCs were immunoreactive for NGF or GDNF. Conclusion NSC can act directly as a gene target cell which not only be infected by the recombinant retrovirus,but also express and secrete the products of exogenous genes.