Objective:To investigate the chemokine receptors expression on regulatory T cells induced by different antigens and chemotaxis of T cells conducted by CCL20 and CCL22.Methods:BALB/c mice were divided into different groups and inoculated with skin-antigen derived from C57BL/6 mice or BCG vaccine respectively.The changes of CCR4 and CCR6 expression on CD4+CD25-T cells and CD4+CD25+CD127-T cells were detected at 1st,2nd,3rd and 4th week using flow cytometer.The chemotactic effects of CCL20 and CCL22 on CD4+CD25-T cells and CD4+CD25+CD127-T cells subsets were assayed by chemotaxis assay.Results: ①In skin-antigen group,the average fluorescence intensity ( MFI) of CCR4 on CD4+CD25-T cells at 4 week was significantly stronger than that at 3 week (P<0.05).There were no significant changes of CCR4 expression in BCG group.②The MFI of CCR6 on CD4+CD25-T cells was strongest at 2 week in skin-antigen group (P<0.05) while in other groups at 4th week (P<0.05).Besides,the expression of CCR6 on CD4+CD25+CD127-T cells was stronger during the first two weeks than the later two weeks ( P<0.05) in skin-antigen group, while in BCG group,the MFI was stronger at 2nd and 4th week than 1st week (P<0.05).③The chemotactic index of CD4+CD25+CD127-T cells was highest at 4th week in BCG group (P<0.05) in CCL20 induced chemotaxis,while in other groups were higher at 2nd and 4th week(P<0.05).In CCL22 induced chemotaxis ,there were no significantly differences of chemotactic index of CD4+CD25+CD127-T cells between skin-antigen group and BCG group.Conclusion:①The expression of chemokine receptor on the surface of Treg was associated with antigenic properties.②CCL22 had a notable chemotactic effect on Treg at the early stage of post-induction, while CCL20 did that at the late stage of post-induction.

Objective:To study the effect of chemokines CCL20 and CCL22 combined with skin-induced Treg on survival time of grafted skin.Methods: Skin grafting mice were divided into four groups, three mice per group, namely Treg group, Treg+CCL20 group,Treg+CCL22 group and control group.C57BL/6 mice were used as donor and BALB/c as acceptor, and the Treg cells were isolated from the mice induced by skin allograft.After skin grafted,CCL20 and CCL22 were subcutaneous injection every day,which lasted for 10 day.Survival time of skin in each group were observed and recorded.The Treg colonzation experiments were performed as follows.We firstly isolated Treg with Magnetic cell sorting system( MACS) and then labled them with 99 Tcm.After that we intravenously injected them into the mice.3 hours later,the mice were sacrifced and the radioactivity of organs were detected by GC-2016γradioim-munoassay counter.Results:①After Treg treated the survival time of skin grafted in antigen-induced Treg group was signifiantly longer than control group,when treg were cooperated with CCL20 and CCL22,the skin grafted showed more longer survival time than Treg and control groups( P<0.001 ).②After injection of induced Treg, Treg in autologous and allogeneic skin grafts goups were mainly distributed in autologous and allogeneic skin,accounting for 60% and 98% respectively.When cooperated with CCL20 or CCL22,the Treg were mainly distributed in liver.Conclusion:Chemokines CCL20 and CCL22 synergistically improved the effects of skin antigen induced Treg on survival time of skin graft,which probably related with the Treg colonization into the liver.

Objective To investigate the epidemiological and molecular virological characteristics in HBV-infected patients with copositive HBsAg and anti-HBs.Methods HBV serological markers were analyzed in 52 070 specimens.The epidemiological characteristics of HBsAg and anti-HBs simultaneously positive patients (the experimental group) and HBsAg positive and auti-HBs negative patients (the control group) were compared.The S protein of HBV coding region was amplified by semi-nested PCR and sequenced.The statistical differences between the two groups were compared in different gene regions,genotypes and different clinical diagnosis.Results HBsAg was positive in 20.40％ (10 621/52 070) of all specimens.In the patients with positive HBsAg,2.48％ (263/10 621) was positive anti-HBs.The prevalence of co-positive HBsAg and auti-HBs was higher in aged 0 to 9 years and greater than or equal to 80 years than that in other age,and the prevalence of positive HBsAg and negative anti-HBs was completely opposite.The mutation rate of S protein in the experimental group was significantly higher than that in the control group (1.52％ vs 0.81％,P ＜0.01) with the mutation in the major hydrophilic region (MHR) (1.68％ vs 0.57％,P ＜0.01).The mutation rates of S protein of HBV carriers,chronic hepatitis B (CHB) patients and patients with liver cirrhosis (LC) in the experimental group were significantly higher than those in the control group (1.47％ vs 0.65％,1.28％ vs 0.84％,2.21％ vs 0.44％,P ＜0.05,respectively),except for the patients with hepatocellular carcinoma (HCC) (1.97％ vs 2.21％,P ＞ 0.05).Conclusion Co-positive HBsAg and anti-HBs in HBV-infected patients was more common in HBsAg positive patients aged 0 to 9 years and greater than or equal to 80 years than the others.Coexistence of HBsAg and anti-HBs in HBV-infected patients may relate to immune escape caused by mutation of S protein (mainly MHR).The mutation rates of S protein in the two groups of patients,co-positive HBsAg and anti-HBs and the positive HBsAg combined with negative anti-HBs,were associated with the stage of liver disease.