ObjectiveTo investigate the proportion of peripheral blood CD4+CD25+ regulatory T cells (Tregs) in patients with pancreatic head carcinoma, the dynamic changes of these cells before and after pancreatoduodenectomy were also analyzed. MethodsThe proportions of peripheral blood CD4+CD25+ Tregs in patients with pancreatic head carcinoma and normal individuals were examined by using flow cytometric analysis. The CD4+/CD8+ ratio was also studied before and after operation. ResultsThe patients with pancreatic head carcinoma showed higher ratio of CD4+CD25+ and CD4+CD25high Tregs compared with normal control before operation (Plt;0.05). However, the percentage of these T cells reduced significantly after pancreatoduodenectomy, which was most obviously on the 3rd day after operation (Plt;0.01, Plt;0.05). After operation, CA199 level began to decrease, which was obvious on the fourteen day after operation. This tendency of CD4+CD25high Tregs changes was similar to that of CA199. The patients showed an decreased ratios of CD4+/CD8+ compared with normal controls, which further declined after operation, and reached the lowest point on the seventh day after operation (Plt;0.05). ConclusionsPancreatoduodenectomy may be helpful for the recovery of antitumor immunity. The perioperative period of patients with pancreatic head carcinoma may be a beneficial windowphase for immune intervention and Tregs may be served as target cells.
ObjectiveTo approach the role of CD4+CD25+ regulatory T cells in the maintenance of immunotolerance in mouse liver allograft. MethodsThe mouse orthotopic liver transplantation was performed. After the liver transplantation immunotolerance induction, antiCD25 monoclonal antibody (PC61) was injected into the recipients with a delayed timing to remove the CD4+CD25+ T cells. The percentage of CD4+CD25+ T cells and the expression of forkhead/winged helix transcription factor (Foxp3) in the recipients were examined. Furthermore, the survival time of the recipient was observed. ResultsC3H/HeJ recipients receiving DBA/2 hepatic allografts survived over 70 d as in the syngeneic liver transplantation (C3H/HeJ recipients receiving C3H/HeJ hepatic grafts). With various protocols of the delayed PC61 treatment, the CD4+CD25+ T cell was completely disappeared as observed. However, the removal of CD4+CD25+ regulatory T cells after the induction of transplantation immunotolerance did not affect the survival of hepatic allografts. ConclusionCD4+CD25+ regulatory T cells are not essential for the maintenance of spontaneous mouse liver transplantation immunotolerance.
Objective To establish a modified mouse abdominal heterotopic heart transplantation model in order to increase the graft survival rate and reduce operative complications. Methods The heart was transplanted into the abdomen by anastomosing the donor ascending aorta and pulmonary artery to the recipient abdominal aorta and infrahepatic vena cava respectively. Hilar tissue was not alone ligated, meanwhile recipient lumbar vein was not ligated. Recipient abdominal aorta and infrahepatic vena cava were not isolated, but were liberated and obstructed simultaneously. Results Two hundred and twenty-nine formal transplantations were performed with the successful rate of 97.82% (224/229). The syngeneic graft survival time was more than 6 months. Complications: Aorta thrombus was found in 2 mice (0.87%), inferior vena cava thrombus in 1 mouse (0.44%), heart torsion in 4 mice (1.75%), hemorrhage in 4 mice (1.75%), crural paralysis in 2 mice (0.87%), intestinal obstruction in 1 mouse (0.44%), and no anesthetic accident happened. Conclusions The meliorated mouse abdominal heterotopic heart transplantation model is simple and reliable, which can reduce the operation time. Thus, the meliorated method provides a useful technique for immunologic transplantation research.