日本血吸虫可溶性虫卵抗原免疫小鼠CD11c^+CD8_α^-DC对过敏性哮喘的抑制作用

The inhibitory effect on asthma of CD11c^+CD8_α^-dendritic cells from mice immunized with Schistosoma japonicum

目的研究日本血吸虫可溶性虫卵抗原(SEA)免疫小鼠CD11c+CD8α-树突状细胞(DC)亚群对卵清白蛋白(OVA)诱发的过敏性哮喘的抑制作用。方法 BALB/c小鼠经腹腔及足垫注射SEA 50μg/只,每周1次,共4次。用抗体包被的免疫磁珠分离小鼠脾CD11c+CD8α+DC与CD11c+CD8α-DC亚群。另取18只BALB/c小鼠,随机分为4组,A组为健康对照组,B组为OVA致敏单纯哮喘组,C组为过继转移SEA免疫CD11c+CD8α+DC组,D组为过继转移SEA免疫CD11c+CD8α-DC组。C、D组小鼠分别经尾静脉过继转移5×105个CD11c+CD8α+DC和5×105个CD11c+CD8α-DC,1h后B、C、D组小鼠同时用OVA诱发哮喘,4周后剖杀,取肺组织,做病理切片,经苏木素-伊红(HE)染色后,光镜下观察肺部炎症变化。结果 A组小鼠肺组织无炎症反应;B组小鼠肺组织炎症反应广泛且严重,在支气管及肺泡周围有大量炎性细胞浸润;C组小鼠肺组织炎症反应仍较明显;D组小鼠肺组织炎症反应较B、C组显著减轻,仅有少量炎细胞浸润。4组小鼠按照Underwood标准进行病理评分,总分分别为0、14.00±1.00、12.33±0.58和7.20±1.30,差异有统计学意义(P<0.05)。结论日本血吸虫SEA免疫小鼠CD11c+CD8α-DC亚群对过敏性哮喘有抑制作用。

Objective To study the inhibition of OVA-induced allergic asthma by CD11c＋CD8α-dendritic cell（DC） subsets from mice immunized with Schistosoma japonicum egg antigens（SEA）.Methods BALB/c mice were injected with 50 μg SEA through the abdominal cavity and foot pad once a week for 4 times in total.Magnetic beads carrying antibodies were used to separate DC subsets into CD11c＋CD8α＋DCs and CD11c＋CD8α-DCs.Eighteen BALB/c mice were randomly divided into four groups： Group A,health control;Group B,asthma alone;Group C,SEA-immune CD11c＋CD8α＋ DCs;and Group D,SEA-immune CD11c＋CD8α-DCs.5×105 CD11c＋CD8α＋ DCs and CD11c＋CD8α-DCs were adoptively transferred to mice in Group C and Group D,respectively,via the caudal vein.One hour later,mice in Groups B,C,and D developed asthma due to OVA at the same time.Four weeks later,all mice were sacrificed and lung tissue was removed to prepare pathology sections;inflammatory changes were observed after HE staining.Results There was no inflammatory reaction in lung tissue from Group A.Severe and extensive inflammation was noted in Group B,which had massive infiltration of inflammatory cells around the bronchi as well as the alveoli.There was marked inflammation in Group C.Compared to Groups B and C,Group D had marked less inflammation,and little infiltration of inflammatory cells was noted.Conclusion CD11c＋CD8α-DCs from mice immunized with Schistosoma japonicum SEA may inhibit allergic asthma.