Investigation Of Alteration And Influencing Factors Of CD4~+CD25~+ Regulatory T Cell In Peripheral Blood Of The Patients With Esophageal Cancer In Peri-operational Period

Background&Objective:Esophageal cancer is one of the most common malignancies in China,and the overall 5-year survival rate remains low.Currently the common clinical therapy to the tumor is generally directed towards the formed tumor cells,such as surgery,chemotherapy and radiation therapy.Chemotherapy and radiation not only kill cancer cells,but also damage the normal immune cells.For the reason,people are tend to a new theory regulating endogenous immune activity to remove tumors,by utilizing organism's own immune mechanism as the important clinical cancer treatment.Tumor immunotherapy treatment,as the represent of tumor biotherapy,has become a new treatment model following surgery,chemotherapy and radiation therapy.The latest research of tumor immunology demonstrated that the occurrence and progress of tumor correlate closely with immune system functional disorder and/or functional defect.The CD4~+CD25~+regulatory T cells,a unique immunoregulation population of T-cell subgroup,can inhibit the immune response of T cells to exogenous and autologous antigen,which induce immune tolerance to their own component and also prevent the organism of autologous homologous tumor cells immune response.Many studies showed that CD4~+CD25~+ regulatory T cells express significantly higher in malignant tumor tissue,such as lung cancer,breast carcinoma, rectal cancer,stomach cancer,ovarian cancer and so on.However,there were only few reports about the expression of Tregs in esophageal cancer.The objective of this research is to detect the level of CD4~+CD25~+regulatory T cells in peripheral blood of the patients with esophageal cancer in peri-operational period,and to explore the related factors with clinical data.It may provide a theory support for adjuvant treatment after surgery.Methods:Peripheral blood samples were collected from 56 patients with esophageal cancer in peri-operational period,and 30 healthy donors(adult who had medical examination) at the same time.All the patients received tumor resection in Shandong province hospital.Mononuclear cells were isolated from the blood samples by lymphocyte separation medium.Then the cells were washed and incubated with mAb(PE anti-human CD4,FITC anti-human CD25,ECD anti-human CD3).After treated,the cells were analyzed with FACS Calibur flow cytometer to detect the T cell subgroup,especially the proportion of CD4~+CD25~+regulatory T cells to CD4~+T cells. All statistic analyses were performed with SPSS 12.0 statistical software,to investigate the level of CD4~+CD25~+ regulatory T cells in peripheral blood of the patients with esophageal cancer in peri-operational period and analyze the influence factors according to the clinical and pathology data.Results:The percentage of CD4~+CD25~+ regulatory T cells in total CD4~+ cells in peripheral blood of patients with esophageal cancer in pre-operation and post-operative 1st week was respectively(17.21±1.94)%,(15.02±1.82)%.Each of them was obviously higher than controls(9.35±1.41)%,with statistical significance (P＜0.01).The percentage of CD4~+CD25~+ regulatory T cells in peripheral blood of patients post-operative 4th week(9.99±1.39)%was higher than controls,but there was no significant difference(P＞0.05).The percentage of CD4~+CD25~+ regulatory T cells in peripheral blood of patients after resection were all significantly lower than that of preoperative(P＜0.01).The percentage of CD3~+T cells and CD3~+CD4~+T cells in peripheral blood of patients post-operative 4th week was(57.34±7.73)%, (35.73±6.64)%respectively,which were lower than those in healthy controls(65.58±10.88)%,(43.05±8.67)%,with statistical significance(P＜0.01).There were no significant differences between the percentage of CD3~+T cells and CD3~+CD4~+T cells in peripheral blood of patients pre-operation and controls,and the same situation referred to those of patients post-operative 4th week and healthy controls.The percentage of CD4~+CD25~+ regulatory T cells in total CD4~+ T cells in peripheral blood of patients atⅠ,Ⅱ,Ⅲstage before operation was respectively (15.35±1.22)%,(16.83±1.50)%,(18.49±1.94)%,while post-operative 1st week was (13.03±0.86)%,(14.76±1.38)%,(16.21±1.84)%,and post-operative 4th week was (8.58±0.74)%,(9.91±1.19)%,(10.66±1.45)%,there was statistical significance between different stages(P＜0.01),which mean that the percentage of CD4~+CD25~+ regulatory T cells was higher in the late stage than the early.The percentage of CD4~+CD25~+ regulatory T cells in total CD4~+ T cells in peripheral blood of patients with lymph node metastasis and without lymph node metastasis before operation was respectively(17.96±2.12)%,(16.19±1.03)%,while post-operative 1st week was (15.85±1.92)%,(13.93±0.88)%,and post-operative 4th week was(10.70±1.40)%, (9.05±0.64)%.There was statistical significance between the two groups(P＜0.01). The percentage of CD4~+CD25~+ regulatory T cells in total CD4~+ T cells in peripheral blood of cancer resection patients receiving blood transfusion and without blood transfusion at the 1st week post-operation was(15.77±1.79)%,(14.23±1.53)% respectively,while post-operative 4th week was(10.64±1.45)%,(9.29±0.93)%.There was statistical significance in different stages(P＜0.01).The percentage of CD4~+CD25~+regulatory T cells in the peripheral blood of cancer resection patients receiving chemotherapy was respectively(10.44±1.45)%,(11.67±1.56)%before and after chemo,with statistical significance(P＜0.01).There was not statistical significance between the percentage of CD4~+CD25~+regulatory T cells in the peripheral blood of patients with different age,sex,tumor location,pathological category,degree of tumor differentiation,depth of tumor infiltration and surgical procedure(P＞0.05).Conclusions:Significantly increased CD4~+CD25~+ regulatory T cells in peripheral blood of the patients with esophageal cancer indicated that there might be a mechanism that compromises the cellular immune function.Significantly decreased CD4~+CD25~+ regulatory T cells in peripheral blood of the post-operative patients with esophageal cancer showed that the operation has alleviated or eliminated the tumor burden,and it might be propitious to recovery of immune function and efficacy of anti-tumor.The percentage of CD3~+T cells and CD3~+CD4~+T cells in peripheral blood of patients at the 1st week post-operation was significantly lower than the patients pre-operation and the 4th week post-operation,which demonstrated that the injury of operation could induce decrease of immune function and the influence was reversible. The percentage of CD4~+CD25~+regulatory T cells in peripheral blood of the patients was related to lymph node metastasis and TMN stage,which suggested it may be relevant to tumor progress,invasion and metastasis.Increased CD4~+CD25~+regulatory T cells of esophageal cancer patients receiving blood transfusion or chemotherapy indicated that the treatments may induce immune suppression.