弓形虫Chinese 1基因型Wh6弱毒株感染小鼠抗强毒株致死性感染的免疫保护作用  

Avirulent Wh6 strain of Toxoplasna gondii genotype Chinese 1 induced complete protective immunity against the challenge of high virulent Wh3 strain in mice

作　　者：陈守斌 何佳丽 崔雯 王聪 陶晴 计永胜 罗庆礼 胡晓东 沈继龙 王维 CHEN Shou-bin;HE Jia-li;CUI Wen;WANG Cong;TAO Qing;JI Yong-sheng;LUO Qing-li;HU Xiao-dong;SHEN Ji-long;WANG Wei(School of Basic Medical Sciences,Anhui Medical University,Department of Microbiology and Parasitology,Anhui Provincial Laboratory of Pathogen Biology and Anhui Key Laboratory of Zoonoses,Hefei 230032,China)

机构地区：[1]安徽医科大学基础医学院,安徽病原生物学省级实验室和人兽共患病安徽省重点实验室,合肥230032

出　　处：《中国人兽共患病学报》2020年第2期87-93,共7页Chinese Journal of Zoonoses

基　　金：国家自然科学基金资助(No.81471983)。

摘　　要：目的研究我国流行的优势基因型Chinese 1弱毒Wh6株感染抗致死性强毒Wh3株攻击感染的保护力,探讨其潜在的制备减毒活疫苗的价值。方法将30只BALB/c雌性小鼠随机分为3组(I,II,III组),每组10只。取弱毒株弓形虫保种小鼠脑组织,分离包囊,计数。I组小鼠灌胃包囊25-35个;II组给与PBS对照;III组正常小鼠不予任何干预。35 d后,I组感染小鼠脑组织压片镜检,查见典型弓形虫包囊,表明慢性弓形虫感染BALB/c小鼠模型建立成功。分别取Wh3株速殖子(3000个),腹腔感染I组和II组小鼠,观察小鼠存活及腹腔虫荷;同时剖杀小鼠,收集脾细胞培养上清,采用流式细胞术、荧光定量PCR、酶联免疫吸附试验等检测脾细胞中的Th1、Th2细胞因子水平。结果II组对照鼠在感染Wh3株弓形虫速殖子后第7 d内死亡5只,第8 d剩余5只全部死亡,随机取3只死亡小鼠对其腹腔进行计数,计数结果为(1.28±0.0351)×106/mL;而I组小鼠截止实验结束全部存活(P<0.01)。II组鼠脾细胞培养上清Th1细胞因子IFN-γ、IL-12和Th2细胞因子IL-10水平相比I组显著升高(P<0.001)。其中Th1细胞因子升高程度明显高于Th2细胞因子,巨噬细胞向Th1方向极化。结论用弱毒株Wh6包囊攻击感染BALB/c鼠,可诱导强力的抵抗Wh3强毒株致死性感染的免疫保护力。Chinese 1基因型Wh6株具有候选减毒活虫疫苗研究的潜在价值。The aim of this study was to explore the protective effect of Toxoplasma gondii avirulent Wh6 strain infection on the challenge of the high virulent strain in BALB/c mice,to find a new attenuated vaccine of viable parasite.Thirty BALB/c female mice were randomly divided into three groups,GroupI,GroupII and Group III.BALB/c mice in Group I were intragastrically infected with 25-35 cysts of Wh6 strains while mice in GroupII treated,with PBS,and additional 10 mice were used as normal control.At 35 days post infection,the brain tissues of mice inoculated with avirulent Wh6 strain were examined for Toxo plasma cysts under microscope.Subsequently the mice of Group I and II were challenged with 3000 tachyzoites of high virulent Wh3 strain.One week after challenge,the survival of mice and parasite burden in the peritoneal cavity were evaluated,spleen cell suspensions were prepared and Th1 and Th2 cells for 3 groups were detected by flow cytometry.Quantitation of Th1 and Th2 cytokines in spleen tissue by qRT-PCR and enzyme-linked immunosorbent assay respectively.All mice in Group I survived for more than 15 days until the experiments ended but the animals in Group II totally died after one week of Wh3 strain infection.The levels of Th1 and Th2 cytokines of IFN-γ,IL-10 and IL-12 in the spleen cell culture supernatant of group II were significantly higher than those in group I(P<0.001).Conclusions:These results indicated that BALB/c mice inoculated with avirulent Wh6 strain may survive the lethal infection of Wh3 strain,suggesting a potential significant role of Wh6 strain in novel approach of viable attenuated parasite vaccine against toxoplasmosis.

关 键 词：弓形虫 疫苗 CHINESE 1基因型 免疫保护 

分 类 号：R382.5[医药卫生—医学寄生虫学]