紫外线辐照致弱RH株弓形虫速殖子及生物学性质的研究  

Research on Ultraviolet irradiation attenuated RH strain Toxoplasma gondii tachyzoites and its biological features

作　　者：徐军[1] 孙新[2] 杨小迪[2] 王媛媛[2] 程启媛[2] 

机构地区：[1]淮南市第一人民医院检验科,安徽淮南市232007 [2]蚌埠医学院病原生物学教研室安徽省感染与免疫重点实验室

出　　处：《热带病与寄生虫学》2009年第2期63-66,共4页Journal of Tropical Diseases and Parasitology

摘　　要：目的探讨紫外线辐照致弱RH株弓形虫的条件以及致弱弓形虫的生物学特性。方法以253.7nm紫外线在室温下辐照一定浓度的弓形虫速殖子,辐照时间为0、0.5、1、2、5、10、20、30、35、40min。台盼蓝染色观察辐照速殖子的活力;辐照速殖子与小鼠黑色素瘤B16细胞共同培养观察对细胞侵入以及在细胞内增殖情况;辐照速殖子接种小鼠,观察小鼠存活时间,判断速殖子在小鼠体内增殖情况;线粒体呼吸实验观察速殖子氧代谢功能;辐照2min速殖子免疫小鼠,60 d后接受同株弓形虫攻击,观察小鼠存活时间。结果紫外线辐照35min内速殖子保持活力,而辐照40min速殖子失去活力。辐照1～35min速殖子均能够侵入B16细胞但失去在细胞和小鼠体内的增殖能力,小鼠在30 d实验观察期内无死亡;与未经辐照的速殖子相比,辐照并没有影响速殖子的氧代谢功能;辐照速殖子免疫小鼠在受到攻击后存活时间较对照组明显延长(P<0.05)。结论在本实验条件下,紫外线辐照1～35min即可致弱弓形虫,致弱弓形虫失去增殖能力,但细胞侵入能力正常,并可以诱导一定的免疫保护力。Objective To study the irradiation condition for attenuating RH strain T. gondii tachyzoites by ultraviolet, and explore the biological features of UV-attenuated tachyzoites. Methods The RH strain T. gondii tachyzoites were irradiated by UV-light with 253.7 nm wave length for 0, 0.5, 1, 2, 5, 10, 20, 30, 35, 40 minutes respectively at room temperature. The viability of UV-irradiated tachyzoites was detected by Trypan blue exclusion test. The cultured mice melanoma cells were incubated with UV- irradiated tachyzoites, and the invasion rates and intracellular multiplication were observed at different time. Mice were injected irradiated tachyzoites intraperitoneally and the mortality rate caused by toxoplasmosis was recorded to estimate the proliferation of irradiated tachyzoites in the mice. Mitochondrial respiratory assay was used to detect the oxidative function of irradiated tachyzoite. Mice were immunized with tachyzoites irradiated by UV for 2 minutes. Two months later, the mice were challenged with live tachyzoites and the survival duration of infected mice was observed. Results The UV- irradiation for 1 to 35 minutes didn't influence the viability of T.gondii. The tachyzoite lost viability when uv-irradiated for 40 minutes. The tachyzoite irradiated for 1 to 35 minutes could invade B16 cell, but there was no reproduction in the cell and mice. All mice inoculated with tachyzoites irradiated for 1 to 35 minutes survived with no symptoms of infection in 30 days. The irradiation of 1 to 35 minutes showed no influence to the metabolism of tachyzoites during the observation period. Immunized mice survived longer than control group (P<0.05). Conclusion In the given condition, UV-irradiation for 1 to 35 minutes can attenuate tachyzoites. The attenuated tachyzoites maintained viability and ability of invading host cells, but lost the ability of proliferation and can induce certain protective immunity against challenge infection.

关 键 词：弓形虫 速殖子 紫外线辐照 致弱 生物学性质 

分 类 号：R1[医药卫生—公共卫生与预防医学]