Rogovskyy Artem S, Casselli Timothy, Tourand Yvonne, Jones Cami R, Owen Jeb P, Mason Kathleen L, Scoles Glen A, Bankhead Troy
Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, United States of America.
Department of Entomology, Washington State University, Pullman, Washington, United States of America.
PLoS One. 2015 Apr 20;10(4):e0124268. doi: 10.1371/journal.pone.0124268. eCollection 2015.
Efficient acquisition and transmission of Borrelia burgdorferi by the tick vector, and the ability to persistently infect both vector and host, are important elements for the life cycle of the Lyme disease pathogen. Previous work has provided strong evidence implicating the significance of the vls locus for B. burgdorferi persistence. However, studies involving vls mutant clones have thus far only utilized in vitro-grown or host-adapted spirochetes and laboratory strains of mice. Additionally, the effects of vls mutation on tick acquisition and transmission has not yet been tested. Thus, the importance of VlsE antigenic variation for persistent infection of the natural reservoir host, and for the B. burgdorferi enzootic life cycle in general, has not been examined to date. In the current work, Ixodes scapularis and Peromyscus maniculatus were infected with different vls mutant clones to study the importance of the vls locus for the enzootic cycle of the Lyme disease pathogen. The findings highlight the significance of the vls system for long-term infection of the natural reservoir host, and show that VlsE antigenic variability is advantageous for efficient tick acquisition of B. burgdorferi from the mammalian reservoir. The data also indicate that the adaptation state of infecting spirochetes influences B. burgdorferi avoidance from host antibodies, which may be in part due to its respective VlsE expression levels. Overall, the current findings provide the most direct evidence on the importance of VlsE for the enzootic cycle of Lyme disease spirochetes, and underscore the significance of VlsE antigenic variation for maintaining B. burgdorferi in nature.
蜱虫媒介高效获取并传播伯氏疏螺旋体，以及持续感染媒介和宿主的能力，是莱姆病病原体生命周期的重要因素。先前的研究提供了有力证据，表明vls位点对伯氏疏螺旋体的持续存在具有重要意义。然而，迄今为止，涉及vls突变克隆的研究仅使用了体外培养或适应宿主的螺旋体以及实验室小鼠品系。此外，vls突变对蜱虫获取和传播的影响尚未得到测试。因此，VlsE抗原变异对自然储存宿主持续感染以及对伯氏疏螺旋体总体生态循环的重要性，迄今尚未得到研究。在当前的研究中，用不同的vls突变克隆感染肩突硬蜱和白足鼠，以研究vls位点对莱姆病病原体生态循环的重要性。研究结果突出了vls系统对自然储存宿主长期感染的重要性，并表明VlsE抗原变异性有利于蜱虫从哺乳动物宿主高效获取伯氏疏螺旋体。数据还表明，感染螺旋体的适应状态会影响伯氏疏螺旋体逃避宿主抗体，这可能部分归因于其各自的VlsE表达水平。总体而言，当前研究结果为VlsE对莱姆病螺旋体生态循环的重要性提供了最直接的证据，并强调了VlsE抗原变异对在自然界中维持伯氏疏螺旋体的重要性。
