Hiob Lysanne, Berndt A, Daugschies A, Bangoura B
Institute of Parasitology, Centre for Infectious Diseases, University Leipzig, An den Tierkliniken 35, D-04103, Leipzig, Germany.
Albrecht-Daniel-Thaer Institute, An den Tierkliniken 29, D-04103, Leipzig, Germany.
Parasitol Res. 2019 May;118(5):1479-1491. doi: 10.1007/s00436-019-06265-2. Epub 2019 Feb 23.
Toxoplasma gondii has the ability to infect various nucleated cell types in different hosts. The aim of the present study was to investigate which chicken blood cells were targeted by T. gondii in a mixed blood cell culture similar to in vivo conditions and to evaluate parasite-host cell interactions. The study consisted of two subsequent experiments. In experiment 1, we applied T. gondii tachyzoites (ME49) at a multiplicity of infection of 1 tachyzoite per blood cell and examined parasite replication, cytokine, and inducible nitric oxide synthase (iNOS) mRNA expression between 1 h and 48 h post-infection (p.i.) by quantitative PCR. By using T. gondii RH-GFP tachyzoites expressing the green fluorescent protein (GFP) in experiment 2, we aimed for visualizing infected cells by confocal laser scanning microscopy (CLSM) and flow cytometric analysis at 24 h p.i. The parasite replication curve showed a massive decrease of parasite stages until 24 h p.i. followed by an approximately plateau phase. We observed mainly significantly increased iNOS mRNA expression levels in T. gondii-infected culture compared to uninfected cells. Flow cytometry and CLSM data confirmed monocytes/macrophages as main target cells for T. gondii. Moreover, different lymphocytes like B cells and cytotoxic T cells seem to be targeted to a low extent. Our findings indicate that monocytes/macrophages play a key role during T. gondii infection in chicken as host cells and triggering of immune response. To the best of our knowledge, this is the first report of a mixed chicken blood cell culture experimentally infected with T. gondii.
刚地弓形虫能够感染不同宿主中的各种有核细胞类型。本研究的目的是在类似于体内条件的混合血细胞培养中，研究刚地弓形虫靶向哪些鸡血细胞，并评估寄生虫与宿主细胞的相互作用。该研究包括两个后续实验。在实验1中，我们以每个血细胞1个速殖子的感染复数应用刚地弓形虫速殖子（ME49），并在感染后1小时至48小时通过定量PCR检测寄生虫复制、细胞因子和诱导型一氧化氮合酶（iNOS）mRNA表达。在实验2中，通过使用表达绿色荧光蛋白（GFP）的刚地弓形虫RH-GFP速殖子，我们旨在在感染后24小时通过共聚焦激光扫描显微镜（CLSM）和流式细胞术分析对感染细胞进行可视化。寄生虫复制曲线显示，直到感染后24小时寄生虫阶段大量减少，随后是一个近似平台期。与未感染细胞相比，我们观察到在刚地弓形虫感染的培养物中iNOS mRNA表达水平主要显著增加。流式细胞术和CLSM数据证实单核细胞/巨噬细胞是刚地弓形虫的主要靶细胞。此外，不同的淋巴细胞如B细胞和细胞毒性T细胞似乎也在低程度上成为靶细胞。我们的研究结果表明，单核细胞/巨噬细胞在刚地弓形虫感染鸡的过程中作为宿主细胞并触发免疫反应发挥关键作用。据我们所知，这是关于刚地弓形虫实验感染鸡混合血细胞培养的首次报告。
