Department of Genetics, Biochemistry and Microbiology, Faculty of Natural and Agricultural Sciences, University of Pretoria, South Africa.
Department of Plant and Soil Sciences, University of Pretoria, South Africa; ACGT Microarray Facility, University of Pretoria, South Africa.
Vaccine. 2020 Oct 14;38(44):6889-6898. doi: 10.1016/j.vaccine.2020.08.060. Epub 2020 Sep 6.
Livestock production is a fundamental source of revenue and nutrition, wherein cattle-farming constitutes one of the major agricultural industries. Vectors and vector-borne diseases constitute one of the major factors that decrease the livelihood of all farming communities, more so in resource-poor communities and developing countries. Understanding the immunological responses during tick infestation in cattle is instrumental in the development of novel and improved tick control strategies, such as vaccines. In this study, gene expression patterns were compared within the lymph nodes of three cattle breeds at different life stages of the cattle tick, Rhipicephalus microplus. For Bonsmara (5/8Bos taurus indicus × 3/8B. t. taurus) cattle specifically, some 183 genes were found to be differentially expressed within the lymph nodes during larval and adult tick feeding, relative to uninfested cattle. Overall, the data provides evidence for a transcriptional regulatory network that is activated during immature tick infestation, but is down-regulated towards basal transcriptional levels when adult ticks are feeding. Specific processes in the lymph nodes of Bonsmara cattle were found to be differentially regulated on a transcriptional level. These include: (1) Leukocyte recruitment to the lymph node via chemokines and chemotaxis, (2) Trans-endothelial and intranodal movement on the reticular network, (3) Active regulation of cellular transcription and translation in the lymph node (including leukocyte associated cellular regulatory networks) and (4) Chemokine receptors regulating the movement of cells out of the lymph node. This work provides a first transcriptome analysis of bovine lymph node responses in tick-infested cattle. Findings show a dynamic immune response to tick infestation for the Bonsmara cattle breed, and that suppression of the maturation of the cattle hosts' immunity is especially evident during the larval feeding stages.
畜牧业是收入和营养的重要来源，其中养牛业是主要的农业产业之一。病媒和媒介传播疾病是降低所有农业社区生计的主要因素之一，在资源匮乏的社区和发展中国家更是如此。了解牛在被蜱虫叮咬时的免疫反应对于开发新型和改进的蜱虫控制策略（如疫苗）至关重要。在这项研究中，比较了三个牛品种在不同牛蜱生活阶段的淋巴结中的基因表达模式。对于邦斯玛拉牛（5/8 印度野牛×3/8 欧洲黄牛），在幼虫和成虫蜱虫取食期间，淋巴结中发现了 183 个差异表达的基因，与未感染的牛相比。总的来说，这些数据为在不成熟的蜱虫感染期间激活的转录调控网络提供了证据，但当成年蜱虫取食时，该网络下调至基础转录水平。邦斯玛拉牛淋巴结中的特定过程在转录水平上被发现存在差异调节。这些过程包括：（1）通过趋化因子和趋化作用将白细胞募集到淋巴结，（2）在网状网络上的跨内皮和淋巴结内运动，（3）在淋巴结中主动调节细胞转录和翻译（包括白细胞相关细胞的调控网络），以及（4）调节细胞离开淋巴结的趋化因子受体。这项工作首次对感染蜱虫的牛的牛淋巴结反应进行了转录组分析。研究结果表明，邦斯玛拉牛对蜱虫感染有动态的免疫反应，而且宿主免疫的成熟抑制在幼虫取食阶段尤为明显。
