AIM: This study investigated the anti-cancer effect ofcombined quercetin and a recombinant adenovirus vectorexpressing the human p53, GM-CSF and B7-1 genes(designated BB-102) on human hepatocellular carcinoma(HCC) cel...AIM: This study investigated the anti-cancer effect ofcombined quercetin and a recombinant adenovirus vectorexpressing the human p53, GM-CSF and B7-1 genes(designated BB-102) on human hepatocellular carcinoma(HCC) cell lines in vitro.METHODS: The sensitivity of HCC cells to anticancer agentswas evaluated by 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The viability of cells infectedwith BB-102 was determined by trypan blue exclusion. Theexpression levels of human wild-type p53, GM-CSF and B7-1genes were determined by Western blot, enzyme-linkedimmunosorbent assay (ELISA) and flow cytometric analysis,respectively. The apoptosis of BB-102-infected or quercetin-treated HCC cells was detected by terminal deoxynucleotidyltransferase (TdT) assay or DNA ladder electrophoresis.RESULTS: Quercetin was found to suppress proliferation ofhuman HCC cell lines BEL-7402, HUH-7 and HLE, with peaksuppression at 50 μmol/L quercetin. BB-102 infection wasalso found to significantly suppress proliferation of HCC celllines. The apoptosis of BB-102-infected HCC cells was greaterin HLE and HUH-7 cells than in BEL-7402 cells. Quercetin didnot affect the expression of the three exogenous genes inBB-102-infected HCC cells (P>0.05), but it was found to furtherdecrease proliferation and promote apoptosis of BB-102-infected HCC cells.CONCLUSION: BB-102 and quercetin synergeticallysuppress HCC cell proliferation and induce HCC cell apoptosis,suggesting a possible use as a combined anti-cancer agent.展开更多
AIM: To study the immunoprotective effect of liver cancer vaccine with co-transfected IL-2 and B7-1 genes on hepatocarcinogenesis in mice.METHODS: The murine liver cancer cell line Hepal-6 was transfected with IL-2 an...AIM: To study the immunoprotective effect of liver cancer vaccine with co-transfected IL-2 and B7-1 genes on hepatocarcinogenesis in mice.METHODS: The murine liver cancer cell line Hepal-6 was transfected with IL-2 and/or B7-1 gene via recombinant adenoviral vectors and the liver cancer vaccines were prepared. C57BL/6 mice were immunized with these vaccines and challenged with the parental Hepal-6 cells afterwards.The immunoprotection was investigated and the reactive T cell line was assayed.RESULTS: The immunoprotection of the tumor vaccine was demonstrated. The effect of IL-2 and B7-1 genes cotransfected Hepal-6 liver cancer vaccine (Hep6-IL2/B7vaccine) on the onset of tumor formation was the strongest.When attacked with wild Hepal-6 cells, the median survival period of the mice immunized with Hep6-IL2/B7 vaccine was the longest (68 days, χ2=7.70-11.69, P<0.05) and the implanted tumor was the smallest (z =3.20-44.10, P<0.05).The effect of single IL-2 or B7-1 gene-transfected vaccine was next to the IL2/B7 gene co-transfected group, and the mean survival periods were 59 and 54 days, respectively.The mean survival periods of wild or enhanced green fluorescence protein gene modified vaccine immunized group were 51 and 48 days, respectively. The mice in control group all died within 38 days and the implanted tumor was the largest (z=3.20-40.21, P<0.05). The cellular immunofunction test and cytotoxicity study showed that the natural killer (NK) cell, lymphokine activated killer (LAK) cell and cytotoxic T lymphocyte (CTL) activities were significantly increased in mice immunized with the Hep6-IL2/B7 vaccine, (29.5±2.5%,65.0±2.9%, 83.1±1.5% respectively, compared with other groups, P<0.05).CONCLUSION: The Hep6-IL2/B7 liver cancer vaccines can induce the mice to produce activated and specific CTL against the parental tumor cells, and demonstrate stronger effect on the hepatocarcinogenesis than single gene modified or the regular tumor vaccine. Therefore, the vaccines may become a novel potential therapy for recurrence and metastasis of HCC.展开更多
Objective: To construct eukaryotic expression vector containing B7-1/GFP geneand study its expression in osteosarcoma cell line LM8. Methods: By using gene cloning technique, eukaxyotic expression vector pEGFP-C1 wa...Objective: To construct eukaryotic expression vector containing B7-1/GFP geneand study its expression in osteosarcoma cell line LM8. Methods: By using gene cloning technique, eukaxyotic expression vector pEGFP-C1 was used to construct the murine B7-1 recombinant plasmid (pEGFP-C1/B7). Recombinant plasmid was transfected into LM8 cells with liposome and was confirmed by restriction endonuclease digestion and DNA sequencing. The expression of the fusion protein was detected using fluorescence microscope and Western blot analysis. Results: The recombinant eukaryotic expression plasmid pEGFP-C1/B7 was successfully constructed, which was confirmed by DNA sequencing, RT-PGR and restriction enzymes analysis. The green fluorescent protein could be detected in the transfected LM8 with fluorescence microscope. The expected B7-1 and green fluorescent protein (GFP) fusion protein was detected by RT-PCR and Western blot. Conclusion: The eukaryotic expression vector containing B7-1/GFP gene was constructed successfully, and it could be expressed in LM8 after transfection.展开更多
Objective: To study the synergic effects of IL-12 and B7-1 transfectant on antitumor immunity in vivo. Methods: The retrovirus vector encoding mIL-12 and mB7-1 gene was tranfected into EL-4 thymic lymphoma cells respe...Objective: To study the synergic effects of IL-12 and B7-1 transfectant on antitumor immunity in vivo. Methods: The retrovirus vector encoding mIL-12 and mB7-1 gene was tranfected into EL-4 thymic lymphoma cells respectively.The cells were used as tumor vaccine and the therapeutic effect was observed. Results: In contrast to the miceimmunized with EL-4/Wt or EL-4/Neo groups, thetumorigenicity of EL-4/IL-12 transfectant was decreased(P<0.001). The EL-4/IL-12 and EL-4/B7-1 cells irradiatedwith 60Co showed significant systematic protective effectsagainst the rechallenge of EL-4/Wt. 60Co irradiatedEL-4/IL-12 cells delayed the occurrence of tumor andprolonged the survival period of tumor bearing mice.Combination of the vaccines of EL-4/IL-12 and EL-4/B7-1 resulted in the enhanced therapeutic effect compared witheach single transfectant group (P<0.001). Conclusion: The results showed that IL-12 transduced cells could enhancethe antitumor immunity of host as cancer vaccine.Combination of the EL-4/IL-12 and EL-4/B7-1 transfectant could improve immunity of host and is a prospect cancervaccine.展开更多
Objective: To study the vaccine potency of gene-modified tumor cells. Methods: The EL-4 lymphoma was transduced with recombinant retrovirus containing the murine GM-CSF gene or B7-1 gene. The effect of gene transducti...Objective: To study the vaccine potency of gene-modified tumor cells. Methods: The EL-4 lymphoma was transduced with recombinant retrovirus containing the murine GM-CSF gene or B7-1 gene. The effect of gene transduction on antitumor immunity was investigated. Results: Flow cytometry analysis showed that expression of their surface marker between wild-type EL-4 cells and gene transduced tumor cells was the same except for CD80 positive in B7-1 gene transduced cells. GM-CSF gene or B7-1 gene transduced EL-4 cells resulted in remarkable loss of tumorigenicity in syngenetic mice. The systemic protective immunity was induced against the challenge with EL-4/wt cells. Therapeutic vaccine with EL-4/GM-CSF or EL/7-1 cells could retard the growth of established early-stage EL-4/wt tumor significantly, but not retard the growth of late-stage EL-4/wt tumor. Irradiated GM-CSF gene transduced EL-4 cells showed strong vaccine effect against EL-4 cell challenge, but irradiated B7-1 gene transduced EL-4 cells showed weak vaccine effect. Remarkable cooperative antitumor effect against EL-4 cell challenge was observed when both irradiated EL-4/GM-CSF and EL-4/B7-1 were inoculated together. Conclusion: GM-CSF gene or B7-1 gene transduced BL-4 cells can be used as a good tumor vaccine. The combination of the two kinds of vaccine may have potential application value in human cancer treatment.展开更多
This work was supposed by CMB (No. 96—635) This is one of papers of the special issue on gene therapy research (Chin J Cancer Res Vol. 9 No. 4 December, 1997). Although cervical carcinoma cells may express the hu...This work was supposed by CMB (No. 96—635) This is one of papers of the special issue on gene therapy research (Chin J Cancer Res Vol. 9 No. 4 December, 1997). Although cervical carcinoma cells may express the human papillomavirus protein E6 and E7, they fail to induce an effective specific cytotoxic T lymphocyte response. Recent studies suggest that expression of CD 80 (B7 1) on tumor cells is effective to induce antitumor immune responses. 1,2 In our study, CD 80 gene was transfected into human Hela cell line with a CD 80 expression plasmid (B7 1 +pcDNA 3) by electroporation, then the immunogenecity of the modified Hela cell was tested in TLMC (tumor lymphocyte mixed culture) system. Thymidine lymphocyte proliferation assays showed that the response of human peripheral blood lymphocytes (PBLS) to CD 80 positive Hela cells demonstrated a substantial increase in cell proliferation compared to the response to control cells. Cocultivation of allogeneic PBLs with CD 80 positive tumor cells for three days can induce an increased secretion of IL 2. Our results demonstrate an immunostimulatory effect of CD 80 expression on cervical cancer cells, which provides a basis for the development of a therapeutic tumor vaccine.展开更多
Summary: Mouse B7 1 cDNA was cloned by RT PCR from BALB/C mouse splenic cells and inserted into pcDNA3 to construct an eukaryotic expression vector. This constructor was named pCD mB7 1, in which the B7 1 cDNA w...Summary: Mouse B7 1 cDNA was cloned by RT PCR from BALB/C mouse splenic cells and inserted into pcDNA3 to construct an eukaryotic expression vector. This constructor was named pCD mB7 1, in which the B7 1 cDNA was identified to be consistent with the data from other researchers. pCD mB7 1 plasmid was transfected into B16(F0) cells, and effective expression of mB7 1 in these tumor cells could be detected till the 6th month by RT PCR and RNA hybridization. Specific cytotoxity assay of lymphocytes was conducted after culturing with tumor cells and the results demonstrated that B16 cells transfected with B7 1 gene were more effective than B16 wt and B16 neo in inducing specific cytotoxity of lymphocytes against B16 wt cells. It is suggested that expression of B7 1 gene in tumor cells could enhance the immunogenicity and induce the effective antitumor immunity.展开更多
Objective: To construct recombinant R7-l/B7-2 retrovirus vectors and observe the effects of B7-l/R7-2 gene expression on in ho and in for immune response against against murine hepatoma. Methods: The recombinant retro...Objective: To construct recombinant R7-l/B7-2 retrovirus vectors and observe the effects of B7-l/R7-2 gene expression on in ho and in for immune response against against murine hepatoma. Methods: The recombinant retrovirus vectors expressing B7-1/B7-2 were constructed by gene cloning technology to produce retrovirus-infected PE501 and PA317 cell lines and murine hepatoma Hepal-6. The expression of R7-l/B7-2 was detected by fluorescence activated cell soning analysis (FACS). B7-l/B7-2 positive Hepal-6 Cell lines were used in inducing anti-hepatoma immunity in ho and in the. Results: In contrast to the excessive growth of parental Hemal-6 tumor, the growth of B7-l/B7-2-positive Hepal-6 inoculated into syngenic mice regressed. B7-1/R7-2-positive or cytokine-treated Hepal-6 alone could only induce mild cytototicity; in contrast, B7-1/B7-2-positive Hemal-6 treated with cytokine-stimulated spleen cells and activated the cytotoxicity effectively. Immunity in mice with R7-1/B7-2-positive tumor cells or cytokine-beated Hepal-6 only provided partial protection against parental Hepa1-6 tumor, whereas pretreatment of the transfected tumor cells with IFN-r and TNF-a induced complete immunity protection in vivo. Mice receiving inoculation of cytokine-treated B7-l/R7-2-positive Hemal-6 cells presented regression of the establoshed pental tUmor and survived for more than l00 d, while those untreated mice died within 40 d. Conclu sions: B7-l/R7-2 expression is necessary but not sufficient in inducing anti-hepatoma immune response, whereas it is efficient when combined with the beatment of IFN-γ and TNF-a.展开更多
The role of B7-1 in podocyte injury has received increasing attention.The aim of this study was to investigate whether losartan protects podocytes of patients with diabetic kidney disease(DKD)by regulating B7-1 and th...The role of B7-1 in podocyte injury has received increasing attention.The aim of this study was to investigate whether losartan protects podocytes of patients with diabetic kidney disease(DKD)by regulating B7-1 and the underlying mechanisms.Rats with streptozotocin-induced DKD were treated with losartan for 8 weeks.Biochemical changes in blood and urine were analyzed.Kidneys were isolated for electron microscopy,immunofluorescence,real-time quantitative PCR(RT-PCR),and Western blot analysis.Immortalized mouse podocyte cells were cultured in normal or high glucose medium in the presence or absence of losartan for 48 h,and then the cells were collected for immunofluorescence,PCR,Western blotting and monolayer permeability detection.The phosphatidylinositol 3-kinase(PI3K)110a subunit and angiotensin II type 1 receptor(AT1R)plasmids were transfected into podocytes,respectively,and then Western blotting was performed to assess the expression of B7-1 protein.The results showed that losartan ameliorated podocyte structure and function in the rat model of DKD,and reduced the expression of B7-1 protein.Overexpression of PI3K 110a subunit in podocytes attenuated the inhibitory effect of losartan on B7-1 expression in high glucose-stimulated podocytes.The expression of B7-1 was significantly increased by overexpression of ATI R and significantly reduced by blocking PI3K 110a subunit.We conclude that losartan protects podocytes against high glucose-induced injury by inhibiting AT1R-mediated B7-1 expression.This effect is dependent on the AT1R-PI3K 110a subunit pathway.展开更多
AIM: To study the activation of cytotoxic T lymphocytes (CTLs) against gastric cancer cells induced by FasL/B7-1 (FB-11) gene-modified tumor cells, and to explore whether co-expression of FasL and B7-1 in SGC-7901 tum...AIM: To study the activation of cytotoxic T lymphocytes (CTLs) against gastric cancer cells induced by FasL/B7-1 (FB-11) gene-modified tumor cells, and to explore whether co-expression of FasL and B7-1 in SGC-7901 tumor cells could initiate synergistic antitumor effect. METHODS: FasL and B7-1 genes were transfected into human SGC-7901 gastric cancer cells with adenovirus vectors. The positive clones were selected by G418. FasL and B7-1 genes were detected by flow cytometry and RT-PCR. Abdominal infiltrating lymphocytes and sensitized spleen cells were obtained from mice that were immunized with SGC-7901/FB-11 or wild type SGC-7901 cells intraperitoneally, and cytotoxicity of these CTLs against tumor cells was determined by MTT assay. RESULTS: Flow cytometry and RT-PCR showed that FasL and B7-1 genes were highly expressed. FasL and B7-1 transfected cancer cells had a high apoptosis index. DNA laddering suggested that FasL and B7-1 genes induced gastric cancer cell apoptosis. FasL+/B7-1+SGC-7901 cells (SGC-7901/FB-11) were inoculated subcutaneously in the dorsal skin of C57BL/6 mice and then decreased their tumorigenicity greatly (z = 2.15-46.10, P<0.01). SGC- 7901/FB-11 cell-sensitized mice obtained protective immune activity against the rechallenge of wild type SGC 7901 cells (z = 2.06-44.30, P<0.05). The cytotoxicity of CTLs induced by SGC-7901/FB-11 cells against SGC-7901 was significantly higher than that of CTLs activated by wild-type SGC-7901 cells (84.1±2.4% vs30.5±2.3%,P<0.05).CONCLUSION: FasL and B7-1 genes can effectively promote the activity of CTLs against gastric cancer cells. FasL/B7-1 molecules play an important role in CTL cytotoxicity.展开更多
文摘AIM: This study investigated the anti-cancer effect ofcombined quercetin and a recombinant adenovirus vectorexpressing the human p53, GM-CSF and B7-1 genes(designated BB-102) on human hepatocellular carcinoma(HCC) cell lines in vitro.METHODS: The sensitivity of HCC cells to anticancer agentswas evaluated by 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The viability of cells infectedwith BB-102 was determined by trypan blue exclusion. Theexpression levels of human wild-type p53, GM-CSF and B7-1genes were determined by Western blot, enzyme-linkedimmunosorbent assay (ELISA) and flow cytometric analysis,respectively. The apoptosis of BB-102-infected or quercetin-treated HCC cells was detected by terminal deoxynucleotidyltransferase (TdT) assay or DNA ladder electrophoresis.RESULTS: Quercetin was found to suppress proliferation ofhuman HCC cell lines BEL-7402, HUH-7 and HLE, with peaksuppression at 50 μmol/L quercetin. BB-102 infection wasalso found to significantly suppress proliferation of HCC celllines. The apoptosis of BB-102-infected HCC cells was greaterin HLE and HUH-7 cells than in BEL-7402 cells. Quercetin didnot affect the expression of the three exogenous genes inBB-102-infected HCC cells (P>0.05), but it was found to furtherdecrease proliferation and promote apoptosis of BB-102-infected HCC cells.CONCLUSION: BB-102 and quercetin synergeticallysuppress HCC cell proliferation and induce HCC cell apoptosis,suggesting a possible use as a combined anti-cancer agent.
基金the National Key Technologies Research and Development during the 9th Five-Year Plan period,Program of China,No.96-905-01-20
文摘AIM: To study the immunoprotective effect of liver cancer vaccine with co-transfected IL-2 and B7-1 genes on hepatocarcinogenesis in mice.METHODS: The murine liver cancer cell line Hepal-6 was transfected with IL-2 and/or B7-1 gene via recombinant adenoviral vectors and the liver cancer vaccines were prepared. C57BL/6 mice were immunized with these vaccines and challenged with the parental Hepal-6 cells afterwards.The immunoprotection was investigated and the reactive T cell line was assayed.RESULTS: The immunoprotection of the tumor vaccine was demonstrated. The effect of IL-2 and B7-1 genes cotransfected Hepal-6 liver cancer vaccine (Hep6-IL2/B7vaccine) on the onset of tumor formation was the strongest.When attacked with wild Hepal-6 cells, the median survival period of the mice immunized with Hep6-IL2/B7 vaccine was the longest (68 days, χ2=7.70-11.69, P<0.05) and the implanted tumor was the smallest (z =3.20-44.10, P<0.05).The effect of single IL-2 or B7-1 gene-transfected vaccine was next to the IL2/B7 gene co-transfected group, and the mean survival periods were 59 and 54 days, respectively.The mean survival periods of wild or enhanced green fluorescence protein gene modified vaccine immunized group were 51 and 48 days, respectively. The mice in control group all died within 38 days and the implanted tumor was the largest (z=3.20-40.21, P<0.05). The cellular immunofunction test and cytotoxicity study showed that the natural killer (NK) cell, lymphokine activated killer (LAK) cell and cytotoxic T lymphocyte (CTL) activities were significantly increased in mice immunized with the Hep6-IL2/B7 vaccine, (29.5±2.5%,65.0±2.9%, 83.1±1.5% respectively, compared with other groups, P<0.05).CONCLUSION: The Hep6-IL2/B7 liver cancer vaccines can induce the mice to produce activated and specific CTL against the parental tumor cells, and demonstrate stronger effect on the hepatocarcinogenesis than single gene modified or the regular tumor vaccine. Therefore, the vaccines may become a novel potential therapy for recurrence and metastasis of HCC.
基金This study was supported by a grant from the youth dawn program of Wuhan (Grant No. 20025001028).
文摘Objective: To construct eukaryotic expression vector containing B7-1/GFP geneand study its expression in osteosarcoma cell line LM8. Methods: By using gene cloning technique, eukaxyotic expression vector pEGFP-C1 was used to construct the murine B7-1 recombinant plasmid (pEGFP-C1/B7). Recombinant plasmid was transfected into LM8 cells with liposome and was confirmed by restriction endonuclease digestion and DNA sequencing. The expression of the fusion protein was detected using fluorescence microscope and Western blot analysis. Results: The recombinant eukaryotic expression plasmid pEGFP-C1/B7 was successfully constructed, which was confirmed by DNA sequencing, RT-PGR and restriction enzymes analysis. The green fluorescent protein could be detected in the transfected LM8 with fluorescence microscope. The expected B7-1 and green fluorescent protein (GFP) fusion protein was detected by RT-PCR and Western blot. Conclusion: The eukaryotic expression vector containing B7-1/GFP gene was constructed successfully, and it could be expressed in LM8 after transfection.
基金supported by a grant from the National"95"Key Project of China(No.96-906A-01-20).
文摘Objective: To study the synergic effects of IL-12 and B7-1 transfectant on antitumor immunity in vivo. Methods: The retrovirus vector encoding mIL-12 and mB7-1 gene was tranfected into EL-4 thymic lymphoma cells respectively.The cells were used as tumor vaccine and the therapeutic effect was observed. Results: In contrast to the miceimmunized with EL-4/Wt or EL-4/Neo groups, thetumorigenicity of EL-4/IL-12 transfectant was decreased(P<0.001). The EL-4/IL-12 and EL-4/B7-1 cells irradiatedwith 60Co showed significant systematic protective effectsagainst the rechallenge of EL-4/Wt. 60Co irradiatedEL-4/IL-12 cells delayed the occurrence of tumor andprolonged the survival period of tumor bearing mice.Combination of the vaccines of EL-4/IL-12 and EL-4/B7-1 resulted in the enhanced therapeutic effect compared witheach single transfectant group (P<0.001). Conclusion: The results showed that IL-12 transduced cells could enhancethe antitumor immunity of host as cancer vaccine.Combination of the EL-4/IL-12 and EL-4/B7-1 transfectant could improve immunity of host and is a prospect cancervaccine.
基金a grant from the "95 National Key Project of China" (No.96-906-01-20).
文摘Objective: To study the vaccine potency of gene-modified tumor cells. Methods: The EL-4 lymphoma was transduced with recombinant retrovirus containing the murine GM-CSF gene or B7-1 gene. The effect of gene transduction on antitumor immunity was investigated. Results: Flow cytometry analysis showed that expression of their surface marker between wild-type EL-4 cells and gene transduced tumor cells was the same except for CD80 positive in B7-1 gene transduced cells. GM-CSF gene or B7-1 gene transduced EL-4 cells resulted in remarkable loss of tumorigenicity in syngenetic mice. The systemic protective immunity was induced against the challenge with EL-4/wt cells. Therapeutic vaccine with EL-4/GM-CSF or EL/7-1 cells could retard the growth of established early-stage EL-4/wt tumor significantly, but not retard the growth of late-stage EL-4/wt tumor. Irradiated GM-CSF gene transduced EL-4 cells showed strong vaccine effect against EL-4 cell challenge, but irradiated B7-1 gene transduced EL-4 cells showed weak vaccine effect. Remarkable cooperative antitumor effect against EL-4 cell challenge was observed when both irradiated EL-4/GM-CSF and EL-4/B7-1 were inoculated together. Conclusion: GM-CSF gene or B7-1 gene transduced BL-4 cells can be used as a good tumor vaccine. The combination of the two kinds of vaccine may have potential application value in human cancer treatment.
文摘This work was supposed by CMB (No. 96—635) This is one of papers of the special issue on gene therapy research (Chin J Cancer Res Vol. 9 No. 4 December, 1997). Although cervical carcinoma cells may express the human papillomavirus protein E6 and E7, they fail to induce an effective specific cytotoxic T lymphocyte response. Recent studies suggest that expression of CD 80 (B7 1) on tumor cells is effective to induce antitumor immune responses. 1,2 In our study, CD 80 gene was transfected into human Hela cell line with a CD 80 expression plasmid (B7 1 +pcDNA 3) by electroporation, then the immunogenecity of the modified Hela cell was tested in TLMC (tumor lymphocyte mixed culture) system. Thymidine lymphocyte proliferation assays showed that the response of human peripheral blood lymphocytes (PBLS) to CD 80 positive Hela cells demonstrated a substantial increase in cell proliferation compared to the response to control cells. Cocultivation of allogeneic PBLs with CD 80 positive tumor cells for three days can induce an increased secretion of IL 2. Our results demonstrate an immunostimulatory effect of CD 80 expression on cervical cancer cells, which provides a basis for the development of a therapeutic tumor vaccine.
文摘Summary: Mouse B7 1 cDNA was cloned by RT PCR from BALB/C mouse splenic cells and inserted into pcDNA3 to construct an eukaryotic expression vector. This constructor was named pCD mB7 1, in which the B7 1 cDNA was identified to be consistent with the data from other researchers. pCD mB7 1 plasmid was transfected into B16(F0) cells, and effective expression of mB7 1 in these tumor cells could be detected till the 6th month by RT PCR and RNA hybridization. Specific cytotoxity assay of lymphocytes was conducted after culturing with tumor cells and the results demonstrated that B16 cells transfected with B7 1 gene were more effective than B16 wt and B16 neo in inducing specific cytotoxity of lymphocytes against B16 wt cells. It is suggested that expression of B7 1 gene in tumor cells could enhance the immunogenicity and induce the effective antitumor immunity.
文摘Objective: To construct recombinant R7-l/B7-2 retrovirus vectors and observe the effects of B7-l/R7-2 gene expression on in ho and in for immune response against against murine hepatoma. Methods: The recombinant retrovirus vectors expressing B7-1/B7-2 were constructed by gene cloning technology to produce retrovirus-infected PE501 and PA317 cell lines and murine hepatoma Hepal-6. The expression of R7-l/B7-2 was detected by fluorescence activated cell soning analysis (FACS). B7-l/B7-2 positive Hepal-6 Cell lines were used in inducing anti-hepatoma immunity in ho and in the. Results: In contrast to the excessive growth of parental Hemal-6 tumor, the growth of B7-l/B7-2-positive Hepal-6 inoculated into syngenic mice regressed. B7-1/R7-2-positive or cytokine-treated Hepal-6 alone could only induce mild cytototicity; in contrast, B7-1/B7-2-positive Hemal-6 treated with cytokine-stimulated spleen cells and activated the cytotoxicity effectively. Immunity in mice with R7-1/B7-2-positive tumor cells or cytokine-beated Hepal-6 only provided partial protection against parental Hepa1-6 tumor, whereas pretreatment of the transfected tumor cells with IFN-r and TNF-a induced complete immunity protection in vivo. Mice receiving inoculation of cytokine-treated B7-l/R7-2-positive Hemal-6 cells presented regression of the establoshed pental tUmor and survived for more than l00 d, while those untreated mice died within 40 d. Conclu sions: B7-l/R7-2 expression is necessary but not sufficient in inducing anti-hepatoma immune response, whereas it is efficient when combined with the beatment of IFN-γ and TNF-a.
基金the National Natural Science Foundation of China(No.81400333).
文摘The role of B7-1 in podocyte injury has received increasing attention.The aim of this study was to investigate whether losartan protects podocytes of patients with diabetic kidney disease(DKD)by regulating B7-1 and the underlying mechanisms.Rats with streptozotocin-induced DKD were treated with losartan for 8 weeks.Biochemical changes in blood and urine were analyzed.Kidneys were isolated for electron microscopy,immunofluorescence,real-time quantitative PCR(RT-PCR),and Western blot analysis.Immortalized mouse podocyte cells were cultured in normal or high glucose medium in the presence or absence of losartan for 48 h,and then the cells were collected for immunofluorescence,PCR,Western blotting and monolayer permeability detection.The phosphatidylinositol 3-kinase(PI3K)110a subunit and angiotensin II type 1 receptor(AT1R)plasmids were transfected into podocytes,respectively,and then Western blotting was performed to assess the expression of B7-1 protein.The results showed that losartan ameliorated podocyte structure and function in the rat model of DKD,and reduced the expression of B7-1 protein.Overexpression of PI3K 110a subunit in podocytes attenuated the inhibitory effect of losartan on B7-1 expression in high glucose-stimulated podocytes.The expression of B7-1 was significantly increased by overexpression of ATI R and significantly reduced by blocking PI3K 110a subunit.We conclude that losartan protects podocytes against high glucose-induced injury by inhibiting AT1R-mediated B7-1 expression.This effect is dependent on the AT1R-PI3K 110a subunit pathway.
基金Supported by the Medical Scientific Foundation of Jiangsu Province, No. H200147
文摘AIM: To study the activation of cytotoxic T lymphocytes (CTLs) against gastric cancer cells induced by FasL/B7-1 (FB-11) gene-modified tumor cells, and to explore whether co-expression of FasL and B7-1 in SGC-7901 tumor cells could initiate synergistic antitumor effect. METHODS: FasL and B7-1 genes were transfected into human SGC-7901 gastric cancer cells with adenovirus vectors. The positive clones were selected by G418. FasL and B7-1 genes were detected by flow cytometry and RT-PCR. Abdominal infiltrating lymphocytes and sensitized spleen cells were obtained from mice that were immunized with SGC-7901/FB-11 or wild type SGC-7901 cells intraperitoneally, and cytotoxicity of these CTLs against tumor cells was determined by MTT assay. RESULTS: Flow cytometry and RT-PCR showed that FasL and B7-1 genes were highly expressed. FasL and B7-1 transfected cancer cells had a high apoptosis index. DNA laddering suggested that FasL and B7-1 genes induced gastric cancer cell apoptosis. FasL+/B7-1+SGC-7901 cells (SGC-7901/FB-11) were inoculated subcutaneously in the dorsal skin of C57BL/6 mice and then decreased their tumorigenicity greatly (z = 2.15-46.10, P<0.01). SGC- 7901/FB-11 cell-sensitized mice obtained protective immune activity against the rechallenge of wild type SGC 7901 cells (z = 2.06-44.30, P<0.05). The cytotoxicity of CTLs induced by SGC-7901/FB-11 cells against SGC-7901 was significantly higher than that of CTLs activated by wild-type SGC-7901 cells (84.1±2.4% vs30.5±2.3%,P<0.05).CONCLUSION: FasL and B7-1 genes can effectively promote the activity of CTLs against gastric cancer cells. FasL/B7-1 molecules play an important role in CTL cytotoxicity.