Clinical and Translational Institute, Sackler School of Biomedical Sciences, Tufts University, 136 Harrison Avenue, Boston, Massachusetts, 02111, USA.
Cummings School of Veterinary Medicine at Tufts University, Building 20, 200 Westborough Avenue, North Grafton, Massachusetts, 01536, USA.
Parasit Vectors. 2018 Mar 12;11(1):176. doi: 10.1186/s13071-018-2754-3.
Human cryptosporidiosis is caused primarily by two species of apicomplexan protozoa, Cryptosporidium parvum and C. hominis. In cultured cell monolayers, the parasite undergoes two generations of asexual multiplication (merogony). However, the proportion of parasites completing the life-cycle is low and insufficient to sustain continuous propagation. Due to the intracellular location of meronts and later life-cycle stages, oocyst and sporozoites are the only forms of the parasite that can readily be isolated.
Research on the replicating forms of Cryptosporidium parasites and their interaction with the host cell remains challenging. Based on an RNA-Seq analysis of monolayers of pig epithelial cells infected with C. parvum, here we report on the impact of merogony on the host's gene regulation. Analysis of the transcriptome of infected and uninfected monolayers demonstrates a significant impact of the infection on host cell gene expression. A total of 813 genes were differentially expressed. Functional terms significantly altered in response to infection include phosphoprotein, RNA binding and acetylation. Upregulation of cell cycle pathways indicates an increase in mitosis. Notably absent from differentially enriched functional categories are stress- and apoptosis-related functions. The comparison of the combined host-parasite transcriptome reveals that C. parvum gene expression is less diverse than the host cell transcriptome and is highly enriched for genes encoding ribosomal functions, such as ribosomal proteins.
These results indicate that C. parvum infection significantly changes host biological functions and provide new insight into gene functions driving early C. parvum intracellular development.
人类隐孢子虫病主要由两种顶复门原生动物引起，即微小隐孢子虫和人隐孢子虫。在培养的细胞单层中，寄生虫经历两代无性繁殖（裂殖生殖）。然而，完成生命周期的寄生虫比例较低，不足以维持连续繁殖。由于裂殖体和后期生命周期阶段位于细胞内，卵囊和孢子囊是唯一易于分离的寄生虫形式。
对隐孢子虫寄生虫的复制形式及其与宿主细胞的相互作用的研究仍然具有挑战性。基于对猪上皮细胞单层感染微小隐孢子虫的 RNA-Seq 分析，我们在这里报告了裂殖生殖对宿主基因调控的影响。感染和未感染单层的转录组分析表明，感染对宿主细胞基因表达有显著影响。共有 813 个基因表达差异。对感染后发生显著变化的功能术语进行分析，包括磷酸蛋白、RNA 结合和乙酰化。细胞周期途径的上调表明有丝分裂增加。值得注意的是，差异富集的功能类别中没有应激和凋亡相关功能。宿主-寄生虫转录组的综合比较表明，微小隐孢子虫的基因表达不如宿主细胞转录组多样化，并且高度富集编码核糖体功能的基因，如核糖体蛋白。
这些结果表明微小隐孢子虫感染显著改变宿主的生物学功能，并为驱动微小隐孢子虫早期细胞内发育的基因功能提供了新的见解。
