Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
Front Cell Infect Microbiol. 2017 Nov 30;7:477. doi: 10.3389/fcimb.2017.00477. eCollection 2017.
The 1976 outbreak of Legionnaires' disease led to the discovery of the intracellular bacterial pathogen . Given their impact on human health, species and the mechanisms responsible for their replication within host cells are often studied in alveolar macrophages, the primary human cell type associated with disease. Despite the potential severity of individual cases of disease, are not spread from person-to-person. Thus, from the pathogen's perspective, interactions with human cells are accidents of time and space-evolutionary dead ends with no impact on 's long-term survival or pathogenic trajectory. To understand as a pathogen is to understand its interaction with its natural hosts: the polyphyletic protozoa, a group of unicellular eukaryotes with a staggering amount of evolutionary diversity. While much remains to be understood about these enigmatic hosts, we summarize the current state of knowledge concerning 's natural host range, the diversity of -protozoa interactions, the factors influencing these interactions, the importance of avoiding the generalization of protozoan-bacterial interactions based on a limited number of model hosts and the central role of protozoa to the biology, evolution, and persistence of in the environment.
1976 年军团病的爆发导致了细胞内细菌病原体的发现。鉴于它们对人类健康的影响，种及其在宿主细胞内复制的机制通常在肺泡巨噬细胞中进行研究，肺泡巨噬细胞是与疾病相关的主要人类细胞类型。尽管个别疾病病例的潜在严重程度很高，但不会在人与人之间传播。因此，从病原体的角度来看，与人类细胞的相互作用是时间和空间的偶然事件——对的长期生存或致病轨迹没有影响。要了解作为一种病原体，就是要了解它与自然宿主的相互作用：多系原生动物，一组具有惊人进化多样性的单细胞真核生物。虽然关于这些神秘的宿主还有很多需要了解，但我们总结了目前关于的自然宿主范围、-原生动物相互作用的多样性、影响这些相互作用的因素、避免根据有限数量的模型宿主对原生动物-细菌相互作用进行概括的重要性，以及原生动物在生物学、进化和持久性中的核心作用在环境中。
