Trail, a tumor necrosis factor-related apoptosis-inducing ligand, is a novel potent endogenous activator of the cell death pathway through the activation of cell surface death receptors Trail-R1 and Trail-R2. Its role...Trail, a tumor necrosis factor-related apoptosis-inducing ligand, is a novel potent endogenous activator of the cell death pathway through the activation of cell surface death receptors Trail-R1 and Trail-R2. Its role, like FasL in activation-induced cell death (AICD), has been demonstrated in immune system. However the mechanism of Trail induced apoptosis remains unclear. In this report, the recombinant Trail protein was expressed and purified. The apoptosis-inducing activity and the regulation mechanism of recombinant Trail on Jurkat T cells were explored in vitro. Trypan blue exclusion assay demonstrated that the recombinant Trail protein actively killed Jurkat T cells in a dose-dependent manner. Trail-induced apoptosis in Jurkat T cells were remarkably reduced by Bcl-2 over expression in Bcl-2 gene transfected cells. Treatment with PMA (phorbol 12-myristate 13-acetate), a PKC activator, suppressed Trail-induced apoptosis in Jurkat T cells. The inhibition of apoptosis by PMA was abolished by pretreatment with Bis, a PKC inhibitor. Taken together, it was suggested that Bcl-2 over-expression and PMA activated PKC actively down-regulated the Trail-mediated apoptosis in Jurkat T cell.展开更多
We have developed and tested chimeric T-cell receptors (TCR) specific for p185HER2. In these experiments, retroviral vectors expressing the N29γ or N29ζ receptors were constructed in pRET6. Amphotropic viral produce...We have developed and tested chimeric T-cell receptors (TCR) specific for p185HER2. In these experiments, retroviral vectors expressing the N29γ or N29ζ receptors were constructed in pRET6. Amphotropic viral producer cells were established in the GALV-based PG13 packaging cell line. Ficoll purified human peripheral blood lymphocytes (PBL) were virally transduced using an optimized protocol incorporating activation with immobilized anti-CD3/anti-CD28 monoclonal anti- bodies, followed by viral infection in the presence of fibronectin fragment CH296. Transduced cells were co-cultured with human tumor cell lines that overexpress (SK-OV-3) or underexpress (MCF7) p185HER2 to assay for antigen specific im- mune responses. Both CM+ and CD8+ T-cells transduced with the N29γ or N29ζ chTCR demonstrated HER2-specific anti- gen responses, as determined by release of Th1 like cytokines, and cellular cytotoxicity assays. Our results support the fea- sibility of adoptive immunotherapy with genetically modified T-cells expressing a chTCR specific for p185HER2.展开更多
目的研究Fas/FasL在绒毛膜癌细胞中的表达,及绒癌细胞与Jurkat细胞共培养诱导T细胞凋亡的机制。方法用免疫荧光染色法检测绒癌细胞系Fas/FasL的阳性表达情况,MTT法检测随时间变化绒癌细胞对Jur-kat细胞的抑制情况,流式细胞仪检测Jurkat...目的研究Fas/FasL在绒毛膜癌细胞中的表达,及绒癌细胞与Jurkat细胞共培养诱导T细胞凋亡的机制。方法用免疫荧光染色法检测绒癌细胞系Fas/FasL的阳性表达情况,MTT法检测随时间变化绒癌细胞对Jur-kat细胞的抑制情况,流式细胞仪检测Jurkat细胞与绒癌细胞共培养24 h、中和抗体NOK-2封闭FasL24 h Jurkat细胞的凋亡情况,透射电镜观察细胞的凋亡形态。结果绒癌细胞上均有Fas及FasL的表达,在绒癌细胞上Fas的阳性表达较低,而FasL表达较多(P<0.05)。绒癌细胞与Jurkat细胞共培养可诱导Jurkat细胞凋亡,绒癌细胞与Jurkat细胞共培养后随着时间的延长Jurkat细胞的凋亡率增加(P<0.05),出现特征性凋亡形态特征。用中和抗体NOK-2封闭细胞表面FasL后,Jurkat细胞的凋亡率下降。结论两种绒癌细胞上均有Fas及Fasl的表达,绒癌细胞能抵抗Fas介导的凋亡,其表面的FasL可抑制T细胞的免疫功能,Fas/FasL途径是绒癌细胞免疫逃逸的重要机制之一。展开更多
Colon cancer is still one of the leading causes of cancer death worldwide. Although the host immune system has been shown to react against tumor cells, mainly through tumor infi ltrating lymphocytes and NK cells, tumo...Colon cancer is still one of the leading causes of cancer death worldwide. Although the host immune system has been shown to react against tumor cells, mainly through tumor infi ltrating lymphocytes and NK cells, tumor cells may utilize different ways to escape anti-tumor immune response. Tumor infi ltration of CD8+ and CD4+ (T-bet+) effector T cells has been attributed to a beneficial outcome, and the enhancement of T cell activation through T cell receptor stimulation and co-stimulatory signals provides promising strategies for immunotherapy of colon cancer. Growing evidence supports a role for the Fas/FasL system in tumor immunology, although the mechanisms and consequences of FasL activation in colon cancer are not completely understood. In animal models, depletion of regulatory T cells (CD4+ CD25+ T cells) can enhance the anti-tumor immune response under certain conditions. Taken together, recent insights in the immune reaction against colon carcinoma have provided new approaches to immunotherapy, although much remains to be learned about the exact mechanisms.展开更多
基金Major State BasicResearch (973) Program of China, (G1999053905).
文摘Trail, a tumor necrosis factor-related apoptosis-inducing ligand, is a novel potent endogenous activator of the cell death pathway through the activation of cell surface death receptors Trail-R1 and Trail-R2. Its role, like FasL in activation-induced cell death (AICD), has been demonstrated in immune system. However the mechanism of Trail induced apoptosis remains unclear. In this report, the recombinant Trail protein was expressed and purified. The apoptosis-inducing activity and the regulation mechanism of recombinant Trail on Jurkat T cells were explored in vitro. Trypan blue exclusion assay demonstrated that the recombinant Trail protein actively killed Jurkat T cells in a dose-dependent manner. Trail-induced apoptosis in Jurkat T cells were remarkably reduced by Bcl-2 over expression in Bcl-2 gene transfected cells. Treatment with PMA (phorbol 12-myristate 13-acetate), a PKC activator, suppressed Trail-induced apoptosis in Jurkat T cells. The inhibition of apoptosis by PMA was abolished by pretreatment with Bis, a PKC inhibitor. Taken together, it was suggested that Bcl-2 over-expression and PMA activated PKC actively down-regulated the Trail-mediated apoptosis in Jurkat T cell.
文摘We have developed and tested chimeric T-cell receptors (TCR) specific for p185HER2. In these experiments, retroviral vectors expressing the N29γ or N29ζ receptors were constructed in pRET6. Amphotropic viral producer cells were established in the GALV-based PG13 packaging cell line. Ficoll purified human peripheral blood lymphocytes (PBL) were virally transduced using an optimized protocol incorporating activation with immobilized anti-CD3/anti-CD28 monoclonal anti- bodies, followed by viral infection in the presence of fibronectin fragment CH296. Transduced cells were co-cultured with human tumor cell lines that overexpress (SK-OV-3) or underexpress (MCF7) p185HER2 to assay for antigen specific im- mune responses. Both CM+ and CD8+ T-cells transduced with the N29γ or N29ζ chTCR demonstrated HER2-specific anti- gen responses, as determined by release of Th1 like cytokines, and cellular cytotoxicity assays. Our results support the fea- sibility of adoptive immunotherapy with genetically modified T-cells expressing a chTCR specific for p185HER2.
文摘目的研究Fas/FasL在绒毛膜癌细胞中的表达,及绒癌细胞与Jurkat细胞共培养诱导T细胞凋亡的机制。方法用免疫荧光染色法检测绒癌细胞系Fas/FasL的阳性表达情况,MTT法检测随时间变化绒癌细胞对Jur-kat细胞的抑制情况,流式细胞仪检测Jurkat细胞与绒癌细胞共培养24 h、中和抗体NOK-2封闭FasL24 h Jurkat细胞的凋亡情况,透射电镜观察细胞的凋亡形态。结果绒癌细胞上均有Fas及FasL的表达,在绒癌细胞上Fas的阳性表达较低,而FasL表达较多(P<0.05)。绒癌细胞与Jurkat细胞共培养可诱导Jurkat细胞凋亡,绒癌细胞与Jurkat细胞共培养后随着时间的延长Jurkat细胞的凋亡率增加(P<0.05),出现特征性凋亡形态特征。用中和抗体NOK-2封闭细胞表面FasL后,Jurkat细胞的凋亡率下降。结论两种绒癌细胞上均有Fas及Fasl的表达,绒癌细胞能抵抗Fas介导的凋亡,其表面的FasL可抑制T细胞的免疫功能,Fas/FasL途径是绒癌细胞免疫逃逸的重要机制之一。
文摘Colon cancer is still one of the leading causes of cancer death worldwide. Although the host immune system has been shown to react against tumor cells, mainly through tumor infi ltrating lymphocytes and NK cells, tumor cells may utilize different ways to escape anti-tumor immune response. Tumor infi ltration of CD8+ and CD4+ (T-bet+) effector T cells has been attributed to a beneficial outcome, and the enhancement of T cell activation through T cell receptor stimulation and co-stimulatory signals provides promising strategies for immunotherapy of colon cancer. Growing evidence supports a role for the Fas/FasL system in tumor immunology, although the mechanisms and consequences of FasL activation in colon cancer are not completely understood. In animal models, depletion of regulatory T cells (CD4+ CD25+ T cells) can enhance the anti-tumor immune response under certain conditions. Taken together, recent insights in the immune reaction against colon carcinoma have provided new approaches to immunotherapy, although much remains to be learned about the exact mechanisms.
