日本血吸虫可溶性虫卵抗原免疫小鼠DC亚群对哮喘的影响及对CCL-11和IL-13Rα2表达的抑制作用

The inhibitory effect of dendritic cell subsets from mice immunized with the soluble egg antigen of Schis tosoma japonicumon asthma and levels of CCL-11 and IL-13Ra2 expression

目的通过过继转移日本血吸虫可溶性虫卵抗原(SEA)免疫的小鼠树突状细胞(DC)亚群,探讨SEA免疫的DC亚群在抑制过敏性哮喘中的作用及可能的作用机制。方法用CD8α和CD11c磁珠分离纯化日本血吸虫SEA免疫小鼠CD8α+DC、CD8α-DC亚群。另取24只BALB/c小鼠,随机分为4组:正常对照组、单纯哮喘组、过继转移SEA免疫CD8α+DC(SEA-CD8α+DC)组和过继转移SEA免疫CD8α-DC(SEA-CD8α-DC)组。SEA-CD8α+DC组、SEA-CD8α-DC组每只小鼠分别经尾静脉过继转移SEA免疫CD8α+DC或CD8α-DC 5×105个。1h后单纯哮喘组、SEA-CD8α+DC组、SEA-CD8α-DC组小鼠同时用卵白蛋白(OVA)诱发哮喘,4周后剖杀,取肺组织做病理切片和免疫组织化学染色,观察炎症变化,同时检测肺组织CCL-11和IL-13Rα2表达情况。结果与单纯哮喘组和SEA-CD8α+DC组比较,SEACD8α-DC组小鼠肺部炎症显著减轻。免疫组化染色后小鼠肺组织CCL-11平均吸光度值分别为:正常对照组0.1496±0.0009,单纯哮喘组1.7121±0.4994,SEA-CD8α+DC组0.9631±0.1201,SEA-CD8α-DC组0.3458±0.0543,SEACD8α-DC组与单纯哮喘组和SEA-CD8α+DC比较差异有统计学意义(P<0.05);小鼠肺组织IL-13Rα2平均吸光度值分别为:正常对照组0.1029±0.0103,单纯哮喘组0.3136±0.0174,SEA-CD8α+DC组0.3263±0.0128,SEA-CD8α-DC组0.1859±0.0294,SEA-CD8α-DC组与单纯哮喘组和SEA-CD8α+DC组比较差异有统计学意义(P<0.05)。结论日本血吸虫SEA免疫的DC亚群对过敏性哮喘有抑制作用,且CD8α-DC亚群起主要作用。

Objective This paper sought to study the inhibitory effect of adoptive transfer of dendritic cell（DC）subsets from mice immunized with the soluble egg antigen（SEA）of Schistosoma japonicum on asthma and its mechanisms.Methods DC subsets from mice infected with S.japonicum were sorted and purified using CD8αand CD11cmicrobeads.Twenty four BALB/c mice were randomly divided into four groups：a normal control group,agroup with untreated asthma,agroup treated by adoptive transfer of SEA CD8α＋DCs（SEA-CD8α＋DCs）,and a group treated by adoptive transfer of SEA CD8α-DCs（SEA-CD8α-DCs）.5×105 CD8α＋DCs and CD8α-DCs from mice immunized with SEA were adoptively transferred via the tail vein to respective mice in the SEA-CD8α＋DC group and SEA-CD8α-DC group.One hour later,mice in the untreated asthma group,SEA-CD8α＋DC group,and SEA-CD8α-DC group were sensitized and challenged with OVA to induce asthma.Four weeks later,all mice were sacrificed.The lungs were removed for histopathological analysis and immunohistochemical staining.Inflammatory changes were observed and levels of CCL-11and IL-13Ra2expression in lung tissue were detected.Results Pulmonary inflammation diminished markedly in mice in the SEA-CD8α-DC group compared to mice in the untreated asthma group and SEA-CD8α＋DC group.Immunohistochemical staining indicated that the average optical density（AOD）of CCL-11-positive regions in mouse lung tissue was 0.1496±0.0009for the normal control group,1.7121±0.4994for the untreated asthma group,0.9631±0.1201for the SEA-CD8α＋DC group,and 0.3458±0.0543for the SEA-CD8α-DC group.The AOD significantly decreased（P0.05）in the SEA-CD8α-DC group compared to that in the untreated asthma group and SEA-CD8α＋DC group.Immunohistochemical staining indicated that the AOD of IL-13Ra2-positive regions in mouse lung tissue was 0.1029±0.0103for the normal control group,0.3136± 0.0174for the untreated asthma group,0.3263±0.0128for the SEA-CD8α＋DC group,and 0.1859±0.0294for the SEA-CD8α-DC group.The AOD significantly decreased（P0.05）in the SEA-CD8α-DC group compared to that in the untreated asthma group and SEA-CD8α＋DC group.Conclusion DC subsets from mice immunized with the SEA of S.japonicumhave an inhibitory effect on allergic asthma,and CD8α-DC subsets play a critical role.