Department of Veterinary Tropical Disease, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa; Agricultural Research Council - Onderstepoort Veterinary Research, Private Bag X5, Onderstepoort 0110, South Africa.
Agricultural Research Council - Onderstepoort Veterinary Research, Private Bag X5, Onderstepoort 0110, South Africa.
Ticks Tick Borne Dis. 2021 May;12(3):101646. doi: 10.1016/j.ttbdis.2020.101646. Epub 2020 Dec 29.
Heartwater is a non-contagious tick-borne disease of domestic and wild ruminants. Data regarding the complex processes involved during pathogen-vector-host interaction during Ehrlichia ruminantium infection is lacking and could be improved with knowledge associated with gene expression changes in both the pathogen and the host. Thus, in the current study, we aimed to identify E. ruminantium genes that are up-regulated when the pathogen enters the host and before the disease is established. Identification of such genes/proteins may aid in future vaccine development strategies against heartwater. RNA-sequencing was used to identify E. ruminantium genes that were exclusively expressed at the tick bite site in sheep skin biopsies (SB) and in adult tick salivary glands (SG). RNA was extracted from pooled samples of the SB or SG collected at different time points during tick attachment and prior to disease manifestation. Ribosomal RNA (rRNA) was removed and the samples were sequenced. Several E. ruminantium genes were highly expressed in all the samples while others were exclusively expressed in each. It was concluded that E. ruminantium genes that were exclusively expressed in the SB or both SB and SG when compared to the transcriptome datasets from bovine elementary bodies (BovEBs) from cell culture may be considered as early antigenic targets of host immunity. In silico immunogenic epitope prediction analysis and preliminary characterization of selected genes in vitro using ELIspot assay showed that they could possibly be ideal targets for future vaccine development against heartwater, however, further epitope characterization is still required.
心水病是一种非传染性的蜱传疾病，影响家养和野生反刍动物。关于绵羊泰勒虫感染过程中病原体-媒介-宿主相互作用的复杂过程的数据尚不清楚，如果能了解病原体和宿主基因表达变化方面的相关知识，这些数据可以得到改善。因此，在本研究中，我们旨在确定当病原体进入宿主并在疾病发生之前被上调的绵羊泰勒虫基因。鉴定这些基因/蛋白可能有助于未来针对心水病的疫苗开发策略。我们使用 RNA 测序来鉴定在绵羊皮肤活检（SB）和成年蜱唾液腺（SG）中蜱叮咬部位特异性表达的绵羊泰勒虫基因。从在蜱附着过程中不同时间点收集的 SB 或 SG 的混合样本中提取 RNA，并在疾病表现之前进行测序。去除核糖体 RNA（rRNA）并对样品进行测序。一些绵羊泰勒虫基因在所有样本中均高度表达，而其他基因则在每个样本中特异性表达。因此，与细胞培养的牛原形体（BovEBs）转录组数据集相比，在 SB 或 SB 和 SG 中特异性表达的绵羊泰勒虫基因可能被认为是宿主免疫的早期抗原性靶标。通过体外 ELIspot 检测分析和对选定基因的初步特征分析，表明它们可能是针对心水病未来疫苗开发的理想靶点，但仍需要进一步的表位特征分析。
