Cellular and immunological mechanisms influence host-adapted phenotypes in a vector-borne microparasite
Cellular and immunological mechanisms influence host-adapted phenotypes in a vector-borne microparasite
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DOI：
10.1098/rspb.2021.2087
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发表时间：
2022-02-23
影响因子：
4.7
通讯作者：
Diuk-Wasser, Maria A.
中科院分区：
文献类型：
--
作者：
Lin, Yi-Pin;Tufts, Danielle M.;Diuk-Wasser, Maria A.
预测病原体出现和溢出风险需要了解病原体宿主范围的决定因素和宿主能力所涉及的特征。虽然宿主能力通常被认为是一个固定的物种特异性特征，它可能是可变的，如果病原体在宿主之间的多样化。平衡选择可以导致病原体多态性的维持（多生态位多态性; MNP）。莱姆病的病原体伯氏疏螺旋体（Borrelia burgdorferi，Bb）提供了研究宿主适应性进化的模型，因为由其外表面蛋白C（ospC）基因型定义的一些Bb菌株在白足小鼠中广泛存在，而其他菌株与非啮齿类脊椎动物（例如鸟类）相关。为了确定潜在的应变X宿主适应的机制，我们感染美国知更鸟和白足小鼠，与三个不同ospC基因型的Bb株。Bb的负担不同的菌株在一个主机依赖的方式，和菌株在主机中的持久性在很大程度上对应于Bb的生存在感染的早期阶段，并与传输到幼虫（即健身）。早期存活表型与细胞粘附、补体逃避和/或炎症和抗体介导的Bb去除相关，表明宿主适应的定向选择压力和MNP在维持OspC多样性中的潜在作用。我们的研究结果将指导未来的调查，为微寄生虫宿主适应的生态进化模型提供信息。
Predicting pathogen emergence and spillover risk requires understanding the determinants of a pathogens' host range and the traits involved in host competence. While host competence is often considered a fixed species-specific trait, it may be variable if pathogens diversify across hosts. Balancing selection can lead to maintenance of pathogen polymorphisms (multiple-niche-polymorphism; MNP). The causative agent of Lyme disease, Borrelia burgdorferi (Bb), provides a model to study the evolution of host adaptation, as some Bb strains defined by their outer surface protein C (ospC) genotype, are widespread in white-footed mice and others are associated with non-rodent vertebrates (e.g. birds). To identify the mechanisms underlying potential strain x host adaptation, we infected American robins and white-footed mice, with three Bb strains of different ospC genotypes. Bb burdens varied by strain in a host-dependent fashion, and strain persistence in hosts largely corresponded to Bb survival at early infection stages and with transmission to larvae (i.e. fitness). Early survival phenotypes are associated with cell adhesion, complement evasion and/or inflammatory and antibody-mediated removal of Bb, suggesting directional selective pressure for host adaptation and the potential role of MNP in maintaining OspC diversity. Our findings will guide future investigations to inform eco-evolutionary models of host adaptation for microparasites.