Department of Veterinary Parasitological Diseases, Faculty of Applied Biological Science, Gifu University, 1-1 Yanagoto, Gifu 501-1193, Japan.
Exp Parasitol. 2013 Jun;134(2):160-4. doi: 10.1016/j.exppara.2013.03.006. Epub 2013 Mar 26.
The intracellular parasite Toxoplasma gondii is thought to disseminate throughout the host by circulation of tachyzoite-infected leukocytes in the blood, and adherence and migration of such leukocytes into solid tissues. However, it is unclear whether T. gondii-infected leukocytes can migrate to solid organs via the general circulation. In this study, we developed a real-time quantitative PCR (qRT-PCR) method to determine the rate of infection of peripheral blood mononuclear cells (PBMCs) flowing into and remaining within solid organs in mice. A transgenic T. gondii parasite line derived from the PLK strain that expresses DsRed Express, and transgenic green fluorescent protein-positive PBMCs, were used for these experiments. Tachyzoite-infected PBMCs were injected into mouse tail veins and qRT-PCR was used to measure the infection rates of the PBMCs remaining in the lungs, liver, spleen and brain. We found that the PBMCs in the lungs and liver had statistically higher infection rates than that of the original inoculum; this difference was statistically significant. However, the PBMC infection rate in the spleen showed no such enhancement. These results show that tachyzoite-infected PBMCs in the general circulation remain in the lungs and liver more effectively than non-infected PBMCs.
内寄生的刚地弓形虫被认为通过血液中感染速殖子的白细胞循环，以及这些白细胞黏附和迁移到实体组织中而在宿主中传播。然而，尚不清楚感染刚地弓形虫的白细胞是否可以通过体循环迁移到实体器官。在这项研究中，我们开发了一种实时定量 PCR（qRT-PCR）方法，以确定流入和留在小鼠实体器官中的外周血单核细胞（PBMC）的感染率。使用源自 PLK 株的表达 DsRed Express 的转基因刚地弓形虫寄生虫系和转基因绿色荧光蛋白阳性 PBMC 进行这些实验。将感染速殖子的 PBMC 注入小鼠尾静脉，并使用 qRT-PCR 测量留在肺、肝、脾和脑中的 PBMC 的感染率。我们发现，肺和肝中的 PBMC 的感染率比原始接种物具有统计学上更高的感染率；这种差异具有统计学意义。然而，脾中的 PBMC 感染率没有显示出这种增强。这些结果表明，循环中的感染速殖子的 PBMC 比未感染的 PBMC 更有效地留在肺和肝中。
