Objective To study the effect of the ECV-304 cells modified with LIF gene on the ex vivo culture of HSC/HPC in cord blood.Methods The ECV-304 cells were infected by Eukaryotic Expression plasmid pcDNA3.0LIF,and the positive ECV-304 cells were obtained by selected with G418.These cells were used to co-culture with CD34+ cells of cord blood.The phenotype of CD34+ and CD34+ CD54+、CD34+ CD62L+ primitive progenitors was detected by flow cytometry.Results The LIF gene can express in ECV-304 cells steadily.ECV-304 cells modified with LIF gene can improve expansion of CB CD34+、CD34+CD54+ and CD34+ CD62L+ cells while sustaining the expression of homing-related adhesion molecule.Conclusion The ECV-304 cells modified with LIF gene can not only significantly expand CB hematopoietic progenitor cells ex vivo,but the expanded CD34+ cells may well retain their homing ability.

Objective:To detect the biological activity of the expression products of the human ?-NGF cDNA in CHO cell line and purified the seperated protein.Methods:Human ?-NGF was transfected with lipofectamine reagent into CHO cell line.The biological activity was analyzed by objection with microscope and the method of MTT.The pure protein was proved by SDS-PAGE analysis.Results:The protein in the culture supernatant of the positive CHO cells transfected with ?-NGF gene could stimulate the growth of PC12 cell line and go into BBB.Conclusion:The target gene expressed successfully in the transfected CHO cell line and had good biological activity. [

Objective:To construct the cells which can express LIF protein steadily and study the effect of rhLIF and IL-24 on HL-60 cells.Methods:ECV-304 cells were infected by eukaryotic expression plasmid pcDNA3-LIF,then the positive cells were selected by G418.The positive cells were collected and their culture supernatant was stored for further use.Expression of LIF mRNA was detected by RT-PCR.The pAdeasy-1-pAdTrack-CMV-IL-24 was extracted from DH5a.The recombined adenovirus vector was lineared with PacI and transfected into 293 cells.The IL-24 recombined adenovirus(Ad-IL-24) was obtained and used to infect HL-60 cells.At the same time,the culture supernatant containing rhLIF was added into the HL-60 cells which was identified as positive expression of IL-24 by RT-PCR.Synergistic effect of the cytokines on HL-60 cells was tested by LSCM, FCM and immunohistochemistry stain assay.Results:The cells expressing LIF protein steadily were constructed successfully, the high titer of the recombined adenovirus(Ad-IL-24) was obtained. Expression of IL-24 in infected HL-60 cells was identified by RT-PCR.The apoptosis of HL-60 cells induced by rhLIF and IL-24 was proved by LSCM ,FCM and immunohistochemistry stain assay. They had synergistic effect.Conclusion:rhLIF and IL-24 can inhibit growth of HL-60 cells and induce apoptosis of the cells.They have synergistic effect.

Objective To construct the human IL-24 recombined adenovirus(Ad-IL24)and to observe the effect of Ad-IL24 on ex vivo culture of HL-60 cells.Methods pAdTrack-CMV-IL24 was constructed by PCR with pcDNA3.0-IL24 recombined plasmid as a template,enzyme digestion and ligation.The pAdTrack-CMV-IL24 lineared by Pme Ⅰ was co-transformed into BJ5183 with pAdEasy-1.The pAdEasy-1-pTrack-CMV-IL24 recombined adenovirus vector was lineared with Pac Ⅰ and then transfected in to QBI-293A cells.The Ad-IL24 was obtained and used to infect HL-60 ceils,and the effect on HL-60 cells was tested by LSCM,Mrrr,FCM,ELISA and immunohistochemistry staining.Results The pAdEasy-1-pTrack-CMV-IL24 vector was constructed and the Ad-IL24 was successfully obtained.The effect of inhibiting growth of HL-60 cells and inducing cell apoptosis by IL-24 was proved by LSCM,MTT and FCM.IL-24 down-regulated the expression of anti-apoptosis factor Bcl-2 and increased the secretion of IFN-γ,TNF-α of HL-60 cells.Conclusion Ad-IL24 can inhibit the growth of HL-60 cells and induce cell apoptosis through down-regulating expression of anti-apoptosis factor and increasing the secretion of IFN-γ,TNF-α of HL-60 cells.The human Ad-IL24 may provide a basic study for the future target therapy to tumors.

Aim To study the expression of β-NGF gene in the mammlian cells and the biological activity of its expression products. Methods The β-nerve growth factor (β-NGF) cDNA which obtained from the plasmid pGEM-β-NGF by enzyme digestion analysis was cloned into the expression vector pcDNA3 to construct the recombinant plasmid pcDNA3-β-NGF. COS-7-cell line grown to log phase was transfected using lipofectamine reagent. The expression level of β-NGF mRNA and the biological activity were analyzed by Northern blot and observation of neurite outgrowth of PC12 cell line stimulated by supernatant, respectively. Results The β-NGF gene was expressed successfully in COS-7 cell lines. The culture supernatant of the positive COS-7 cells transfected with pcDNA3-β-NGF could stimulate the neurite outgrowth of PC12 cell line. Conclusion The target gene expressed successfully in the transfected COS-7 cell line and had good biological activity.

Objective:To construct a recombinant prokaryotic expression vector pGEX-5X-3/hIL-17F and express it in E.coli and to explore the biological activities of human IL-17F fusion protein.Methods:The coding sequence of the mature human IL-17F(minus the signal peptide) was amplified from pUCm-T/hIL-17F by PCR and subcloned into the prokaryotic expression vector pGEX-5X-3 to express glutathione S-transferase(GST) fusion protein. The fusion protein was induced in E.coli BL21 by IPTG and purified by standard methods reported in prokaryotic system. The purified GST-hIL-17F fusion protein was identified by Western blot. The proliferation of ECV304 cells was observed by incubating them with soluble GST-hIL-17F fusion protein by MTT assay. The concentrations of IL-6, IFN-? and TNF-? in the supernatants of ECV304 cells were determined by ELISA. The effect of GST-hIL-17F on the angiogenesis of the chick chorioallantoic membrane was assessed by CAM assay.Results:A 41 kD fusion protein was effciently induced in E.coli BL21 by IPTG, accounting for about 55% of the total bacterial protein. The purified GST-hIL-17F fusion protein was identified by Western blot. GST-hIL-17F fusion protein had obvious biological activity to inhibit the proliferation of ECV304 cells and enhance IL-6 secretion. GST-hIL-17F had a marked antiangiogenic activity.Conclusion:The preliminary study of hIL-17F recombinant prokaryotic expression and its antiangiogenic effect has been successful, which lays a foundation for future research on the mechanism of antiangiogenesis and clinical application of recombinant hIL-17F protein.

Aim To construct the eukaryotic expression vector of hIL-24 cDNA,and express it in CHO cells and detect its anti-tumor effect of recombinant hIL-24 protein.Methods Constructed pcDNA3-hIL-24 was identified by endonucleases digestion & PCR.The recombinant expression plasmids were transfected into CHO cells,human hIL-24 expressed in CHO cells was detected with RT-PCR.The apoptosis-inducing activities of recombinant protein hIL-24 was tested by MTT assay,Hoechst& FCM assay,and the expression of IL-6 and IFN-? from PBMC induced by rhIL-24 was tested by ELISA.Results The eukaryotic expression vector pcDNA3-hIL-24 was constructed correctly.Stable expression of human IL-24 in CHO cells was identified with RT-PCR.The apoptosis of A549 cells induced by hIL-24 was proved by Hoechst & FCM assay,and the expression of IL-6 and IFN-? from PBMC induced by rhIL-24 was identified with ELISA.Conclusion The successful stable expression & experimental study of apoptosis effect of human IL-24 gene lay the foundation for the further study of molecular mechanism of hIL-24 on anti-tumors and potential application.

Objective To establish Ad-LIF-OSM transgenic feeder cells for the expansion of CD34+ hematopoietic stem/progenitor cell and tentatively study its effect in expansion and differentiation of cord blood hematopoietic stem cell(HSC) in vitro.Methods In the foundation of pAdTrack-CMV-LIF-polyA+promoterΔ,the OSM gene was inserted to the vector plasmid.Then we structure the transfer plasmid pAdTrack-CMV-LIF-polyA+promoterΔ-OSM.The transfer vector and backbone vector were further cotransfected for homologous recombination. The result pAdEasy-1-pAdTrack-CMV-LIF-polyA + promoterΔ-OSM homologous recombination plasmid were transfected into the human embryonic kidney 293 (QBI-293A) cells,leading to formation of the recombinant adenviruses Ad-LIF-OSM which co-expressing LIF and OSM.Infect the feeder layer cells with groups of Adenovirus,detection the expressing of LIF and OSM in WI-38 cells by RT-PCR and ELISA.Compares the stem cells differentiation and proliferation of the different experimental groups in vitro by transwell and cell counting.Results The sequencing results show that the OSM genes were anastomotic in Ad-LIF-OSM.LIF and OSM gene could be detected in feeder layer cells which infected by Ad-LIF-OSM.Exogenetic LIF and OSM have special effect in culturing HSC in vitro.Conclusion The adenoviral vector co-expressing LIF and OSM (Ad-LIF-OSM) were successfully constructed.Ad-LIF-OSM transgenic feeder cells can effectively proliferate umbilical cord blood CD34+ HSPC in vitro and delay it differentiate.

Objective To study the antitumor effect and mechanism of co-cultured cytokine-induced killer(CIK) cells and autologous DC modified with IL-24 gene on A549 cells in vitro. Methods DC and CIK cells were prepared routinely from human peripheral blood mononuclear cells(PBMC). Recombinant adenovirus vector pAdEasy-1-pTrack-CMV-IL-24 was extracted from DH5α, it was lineared with Pac I and transfected into A293 cells, and then the IL-24 recombined adenovirus(Ad-IL-24) was obtained. Ad-IL-24 was used to infect DC. The cells obtained were named DC-IL-24. RT-PCR and ELISA were used to evaluate the expression of IL-24 gene in transfected DC. The phenotypes change of DC were identified by flow cytometry analysis, the concen-tration of IL-12 and TNF-α in supernatant of DC were determined by EIJSA. The ability of CIK producing per-forin was measured by homolysis method. FCM was used to determine the cytotoxicity of cocultured CIK cells and autologous DC modified with IL-24 gene to A549 cells. Results We obtained the high titre of Ad-IL-24.IL-24 gene was transfered into DC successfully via Ad-IL-24. The green fluorescence was observed on DC by fluorescence microscope. The expression rate of CD80, CD83, HI.A-DR, CD40, CXCR4 on DC-IL-24 was sig-nificantly increased compared with that of the control group. DC-IL-24 produced markedly higher levels of IL-12 and TNF-α as compared with DC. DC-IL-24 can enhance the ability of CIK cells producing perforin. On com-parison with non-transfected DC co-cultured with CIK cells, transfected DC co-cultured with CIK cells had a sig-nificantly higher lytic activity against A549 cells. Conclusion IL-24 gene modification can enhance the anti-tu-moral immunity of DC. The mechanism of which might be related to the increased secretion of IL-12 and TNF-α, up-regulation expression of co-stimulatory molecules and MHC Ⅱ class molecules on DC, promoting the acti-vation and maturation of DC, and then enhancing CIK cells to generate specific anti-tumoral immunity.

Objective:To study the antitumor effect and mechanism of cocultured CIK cells modified with IL-24 gene and autologous DCs on HL-60 cells in vitro.Methods:DCs and CIK cells were prepared routinely from human peripheral blood mononuclear cells ( PBMC).IL-24 gene was transferred into CIK cells via electroporation.The cells obtained were named CIK-IL24.RT-PCR and ELISA were used to evaluate expression of IL-24 gene in transfected CIK cells.The phenotypic changes of CIK cells were identified by flowcytometry analysis.The concentration of IFN-γ and TNF-α in supernatant of CIK was determined by ELISA.FCM was used to determine the cytotoxicity of cocultured CIK cells modified with IL-24 gene and autologous DCs against HL-60 cells.Results:Eukaryotic expressing plasmid pcDNA3.0-IL24 was transferred into CIK cells successfully via electroporation.The expressing rate of CD3~+、CD3~+CD56~+ cells had no significant change in CIK cells.However,the rate of CD4~+CD25~+ cells was significantly decreased compared with that of the control group.Expression of adhesion molecules CD54,CXCR4 were significantly increased on CD3+CD56+ cells.CIK-IL24 cells produced markedly higher levels of IFN-γ and TNF-α as compared with the CIK cells.By comparison with non-transfected CIK cells co-cultured with DCs,transfected CIK cells co-cultured with DCs had a significantly higher lytic activity against HL-60 cells.Conclusion:IL-24 gene modification can enhance the anti-tumoral immunity of CIK cells,the mechanism of which might be related to the increased secretion of IFN-γ,TNF-α,up-regulation of adhesion molecule expression,and reduction of the rate of CD4~+CD25~+ cells in CIK cells.