Bioluminescence imaging of Toxoplasma gondii infection in living mice reveals dramatic differences between strains
Bioluminescence imaging of Toxoplasma gondii infection in living mice reveals dramatic differences between strains
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DOI：
10.1128/iai.73.2.695-702.2005
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发表时间：
2005-02-01
影响因子：
3.1
通讯作者：
Boothroyd, JC
中科院分区：
文献类型：
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作者：
Saeij, JPJ;Boyle, JP;Boothroyd, JC
我们使用基于生物发光的成像系统研究了原生寄生虫弓形虫的体内生长、传播和再激活。两种弓形虫菌株，一种在小鼠中具有高致病性表型（S23），另一种具有低1000倍致病性表型（S22），被设计为稳定表达发光蛋白荧光素酶。每个野生型菌株分离一个克隆，发现两个克隆（S23-luc7和S22-luc2）表达相似水平的荧光素酶。小鼠腹腔感染S23-luc7（50或5只寄生虫）或S22-luc2（500、50或5只寄生虫），注射荧光素酶底物后无创检测感染进展。D-luciferin。在感染了50种S23-luc7寄生虫的小鼠中，寄生虫在腹腔内（通过表达荧光素酶的寄生虫发出的光来测量）在第1天至第10天呈指数增长，这种增殖一直持续到出现严重疾病。在感染了500种S22-luc2寄生虫的小鼠中。在第1至第6天，寄生虫以与S23-luc7相似的方式增殖，但随后信号急剧下降到低于检测极限的水平。利用这种技术，我们还能够观察到弓形虫在慢性感染小鼠体内的再激活过程。在地塞米松治疗后，我们检测了感染S23-luc7和S22-luc2的小鼠弓形虫病的再激活。在再激活过程中，S23-luc7的生长最初主要在头颈部区域被检测到。而在感染s22 -luc2的小鼠中，寄生虫主要在腹部检测到。该方法在鉴定不同弓形虫菌株传播和生长的重要差异方面具有很大的潜力。尤其是那些疾病结果截然不同的菌株。
We examined the in vivo growth, dissemination, and reactivation of strains of the protozoan parasite Toxoplasma gondii using a bioluminescence-based imaging system. Two T. gondii strains, one with a highly virulent disease phenotype in mice (S23) and the other with a 1,000-fold-lower virulence phenotype (S22), were engineered to stably express the light-emitting protein luciferase. One clone of each wild-type strain was isolated, and the two clones (S23-luc7 and S22-luc2) were found to express similar levels of luciferase. Mice were infected intraperitoneally with S23-luc7 (50 or 5 parasites) or S22-luc2 (500, 50, or 5 parasites), and the progress of the infections was examined noninvasively following injection of the substrate for luciferase. D-luciferin. In mice infected with 50 S23-luc7 parasites, the parasites grew exponentially within the peritoneal cavity (as measured by light emitted from luciferase-expressing parasites) during days 1 to 10 p.i., and this proliferation continued until there was severe disease. In mice infected with 500 S22-luc2 parasites. the parasites proliferated in a fashion similar to the S23-luc7 proliferation during days 1 to 6, but this was followed by a precipitous drop in the signal to levels below the limit of detection. Using this technique, we were also able to observe the process of reactivation of T. gondii in chronically infected mice. After treatment with dexamethasone, we detected reactivation of toxoplasmosis in mice infected with S23-luc7 and S22-luc2. During reactivation, growth of S23-luc7 was initially detected primarily in the head and neck area. while in S22-luc2-infected mice the parasites were detected primarily in the abdomen. This method has great potential for identifying important differences in the dissemination and growth of different T. gondii strains. especially strains with dramatically different disease outcomes.