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 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
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.
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.
