AIM: To investigate the potential role of cytokines in promoting Fas ligand (FasL)-expressing colon cancer cells. METHODS: Immunohistochemical SABC method was used to observe the expression of Fas receptor and ligand ...AIM: To investigate the potential role of cytokines in promoting Fas ligand (FasL)-expressing colon cancer cells. METHODS: Immunohistochemical SABC method was used to observe the expression of Fas receptor and ligand in SW620 colon cancer cell line and Jurkat T cells in order to provide the morphological evidence for the functions of Fas receptor and ligand. To examine the cytotoxicity of effector cells, CytoTox96 non-radioactive cytotoxicity assay was adopted to measure the lactate dehydrogenase-releasing value after SW620 cells were co-cultured with Jurkat T lymphocytes. RESULTS: The FasL of colon cancer SW620 cells was positive. The positive substances were distributed in the cell membrane and cytoplasm. The Fas receptor of colon cancer SW620 cells was negative. The Fas receptor and ligand of Jurkat T lymphocytes turned out to be positive. The positive substances were distributed in the cell membrane. After phytohemagglutinin (PHA)-stimulated Jurkat T lymphocytes were co-cultured with phorbol 12-myristate 13-acetate (PMA)-plus-ionomycin-stimulated (for 48 h) SW620 cells or tumor necrosis factor-alpha (TNF-α)-stimulated (for 48 h) SW620 cells or unstimulated SW620 cells for 4 h, the cytotoxicity of SW620 cells to PHA-stimulated Jurkat cells at effector-to-target ratios of 10:1, 5:1, 2.5:1, and 1.25:1 was 74.6%, 40.8%, 32.4%, and 10.9% (F= 8.19, P<0.05); or 54.9%, 35.3%, 22.0%, and 10.3% (F= 11.12, P<0.05); or 14.9%, 10.5%, 6.9%, and 5.8% (F = 3.45, P<0.05). After PHA-stimulated Jurkat T lymphocytes were co-cultured with unstimulated SW620 cells for 8 h, the cytotoxicity of SW620 cells to PHA-stimulated Jurkat cells at effector-to-target ratios of 5:1, 2.5:1, and 1.25:1 from the experiment was 83.9%, 74.1%, and 28.5% (F=137.04, P<0.05) respectively. Non-radioactive cytotoxicity assay showed that the apoptotic rate of Jurkat cells remarkably increased with the increase of planting concentration of SW620 cells and co-culture time after the SW620 cells were co-cultured with the Jurkat T lymphocytes. The cytotoxici展开更多
To detect oral administration of recombinant human insulin to nonobese diabetic (NOD) mice for preventing them from diabetes and insulitis and to detect the effects of oral administration of insulin on Fas and Fas lig...To detect oral administration of recombinant human insulin to nonobese diabetic (NOD) mice for preventing them from diabetes and insulitis and to detect the effects of oral administration of insulin on Fas and Fas ligand expression on islet of Langerhans Methods Sixty four female NOD mice were divided into two groups One group (34) was orally administered recombination human insulin 1?mg in 500?μl PBS and the other (30) 500?μl PBS only at age of 5 weeks old, twice a week for the first week, then weekly until 30 weeks of age Results Oral administration of insulin to female NOD mice can significantly suppress diabetes and insulitis The insulitis was less severe in the group fed with insulin than that in the control group (score of insulitis: 1 25±0 45 vs 3 0±0 76 at 16 weeks of age, P <0 01) We examined Fas ligand and Fas expression on islets of Langerhans in both groups of NOD mice by using immunohistochemical techniques We find that Fas only expressed on islets when the mice suffered the diabetes, whereas Fas ligand expressed on islets of the mice fed with insulin at 16 and 20 week of ages We did not find Fas ligand positive staining on the islet feeding with PBS Conclusion We speculated that oral insulin may induce Fas ligand expression on the islets and plays a role in protecting the pancreatic β cell from autoimmune destruction These results show that oral insulin affected autoimmune diabetes and insulitis in NOD mice The immune mechanism of oral tolerance is closely related to the change of Fas ligand and Fas system展开更多
基金Supported by the Science and Technology Commission Foundation of Tianjin, No. 003119711
文摘AIM: To investigate the potential role of cytokines in promoting Fas ligand (FasL)-expressing colon cancer cells. METHODS: Immunohistochemical SABC method was used to observe the expression of Fas receptor and ligand in SW620 colon cancer cell line and Jurkat T cells in order to provide the morphological evidence for the functions of Fas receptor and ligand. To examine the cytotoxicity of effector cells, CytoTox96 non-radioactive cytotoxicity assay was adopted to measure the lactate dehydrogenase-releasing value after SW620 cells were co-cultured with Jurkat T lymphocytes. RESULTS: The FasL of colon cancer SW620 cells was positive. The positive substances were distributed in the cell membrane and cytoplasm. The Fas receptor of colon cancer SW620 cells was negative. The Fas receptor and ligand of Jurkat T lymphocytes turned out to be positive. The positive substances were distributed in the cell membrane. After phytohemagglutinin (PHA)-stimulated Jurkat T lymphocytes were co-cultured with phorbol 12-myristate 13-acetate (PMA)-plus-ionomycin-stimulated (for 48 h) SW620 cells or tumor necrosis factor-alpha (TNF-α)-stimulated (for 48 h) SW620 cells or unstimulated SW620 cells for 4 h, the cytotoxicity of SW620 cells to PHA-stimulated Jurkat cells at effector-to-target ratios of 10:1, 5:1, 2.5:1, and 1.25:1 was 74.6%, 40.8%, 32.4%, and 10.9% (F= 8.19, P<0.05); or 54.9%, 35.3%, 22.0%, and 10.3% (F= 11.12, P<0.05); or 14.9%, 10.5%, 6.9%, and 5.8% (F = 3.45, P<0.05). After PHA-stimulated Jurkat T lymphocytes were co-cultured with unstimulated SW620 cells for 8 h, the cytotoxicity of SW620 cells to PHA-stimulated Jurkat cells at effector-to-target ratios of 5:1, 2.5:1, and 1.25:1 from the experiment was 83.9%, 74.1%, and 28.5% (F=137.04, P<0.05) respectively. Non-radioactive cytotoxicity assay showed that the apoptotic rate of Jurkat cells remarkably increased with the increase of planting concentration of SW620 cells and co-culture time after the SW620 cells were co-cultured with the Jurkat T lymphocytes. The cytotoxici
文摘采用酶联免疫夹心法 (EL ISA)检测了 2 5例特发性血小板减少性紫癜 (ITP)患者血清中 s Fas、s Fas L的水平。结果显示 ITP患者血清 s Fas含量为 16 .5 1± 6 .86μg/ L ,s Fas L含量为 0 .48± 0 .33μg/ L ,均显著高于正常对照 (分别为 P<0 .0 0 1和 P<0 .0 1) ;18例 ITP患者血清 s Fas水平升高 ,其中有 9例同时有 s Fas L水平升高 ,但是血清 s Fas水平升高组的血小板计数与 s Fas正常组无显著差异。提示 s Fas和 s Fas L
文摘To detect oral administration of recombinant human insulin to nonobese diabetic (NOD) mice for preventing them from diabetes and insulitis and to detect the effects of oral administration of insulin on Fas and Fas ligand expression on islet of Langerhans Methods Sixty four female NOD mice were divided into two groups One group (34) was orally administered recombination human insulin 1?mg in 500?μl PBS and the other (30) 500?μl PBS only at age of 5 weeks old, twice a week for the first week, then weekly until 30 weeks of age Results Oral administration of insulin to female NOD mice can significantly suppress diabetes and insulitis The insulitis was less severe in the group fed with insulin than that in the control group (score of insulitis: 1 25±0 45 vs 3 0±0 76 at 16 weeks of age, P <0 01) We examined Fas ligand and Fas expression on islets of Langerhans in both groups of NOD mice by using immunohistochemical techniques We find that Fas only expressed on islets when the mice suffered the diabetes, whereas Fas ligand expressed on islets of the mice fed with insulin at 16 and 20 week of ages We did not find Fas ligand positive staining on the islet feeding with PBS Conclusion We speculated that oral insulin may induce Fas ligand expression on the islets and plays a role in protecting the pancreatic β cell from autoimmune destruction These results show that oral insulin affected autoimmune diabetes and insulitis in NOD mice The immune mechanism of oral tolerance is closely related to the change of Fas ligand and Fas system
