Mateos-Hernández Lourdes, Obregón Dasiel, Maye Jennifer, Borneres Jeremie, Versille Nicolas, de la Fuente José, Estrada-Peña Agustín, Hodžić Adnan, Šimo Ladislav, Cabezas-Cruz Alejandro
UMR BIPAR, INRAE, ANSES, Ecole Nationale Vétérinaire d'Alfort, Université Paris-Est, Marie Curie, 94706 Maisons-Alfort, France.
School of Environmental Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada.
Vaccines (Basel). 2020 Nov 21;8(4):702. doi: 10.3390/vaccines8040702.
The tick microbiota is a highly complex ensemble of interacting microorganisms. Keystone taxa, with a central role in the microbial networks, support the stability and fitness of the microbial communities. The keystoneness of taxa in the tick microbiota can be inferred from microbial co-occurrence networks. Microbes with high centrality indexes are highly connected with other taxa of the microbiota and are expected to provide important resources to the microbial community and/or the tick. We reasoned that disturbance of vector microbiota by removal of ubiquitous and abundant keystone bacteria may disrupt the tick-microbiota homeostasis causing harm to the tick host. These observations and reasoning prompted us to test the hypothesis that antibodies targeting keystone bacteria may harm the ticks during feeding on immunized hosts. To this aim, in silico analyses were conducted to identify keystone bacteria in the microbiota of nymphs. The family Enterobacteriaceae was among the top keystone taxa identified in microbiota. Immunization of α-1,3-galactosyltransferase-deficient-C57BL/6 (α1,3GT KO) mice with a live vaccine containing the Enterobacteriaceae bacterium strain BL21 revealed that the production of anti- and anti-α-Gal IgM and IgG was associated with high mortality of nymphs during feeding. However, this effect was absent in two different strains of wild type mice, BALB/c and C57BL/6. This result concurred with a wide distribution of α-1,3-galactosyltransferase genes, and possibly α-Gal, in Enterobacteriaceae and other bacteria of tick microbiota. Interestingly, the weight of nymphs that fed on -immunized C57BL/6 was significantly higher than the weight of ticks that fed on C57BL/6 immunized with a mock vaccine. Our results suggest that anti-tick microbiota vaccines are a promising tool for the experimental manipulation of vector microbiota, and potentially the control of ticks and tick-borne pathogens.
蜱虫微生物群是由相互作用的微生物组成的高度复杂的集合体。在微生物网络中起核心作用的关键分类群，维持着微生物群落的稳定性和适应性。蜱虫微生物群中分类群的关键性可通过微生物共现网络推断得出。中心性指数高的微生物与微生物群的其他分类群高度相连，有望为微生物群落和/或蜱虫提供重要资源。我们推测，去除普遍存在且数量丰富的关键细菌会干扰媒介微生物群，从而破坏蜱虫-微生物群的稳态，对蜱虫宿主造成伤害。这些观察结果和推理促使我们检验这样一个假设，即靶向关键细菌的抗体可能会在蜱虫吸食免疫宿主时对其造成伤害。为此，我们进行了计算机分析，以确定若虫微生物群中的关键细菌。肠杆菌科是在微生物群中鉴定出的顶级关键分类群之一。用含有肠杆菌科细菌菌株BL21的活疫苗免疫α-1,3-半乳糖基转移酶缺陷型C57BL/6（α1,3GT KO）小鼠，结果显示，抗α-Gal IgM和IgG的产生与若虫在吸食过程中的高死亡率相关。然而，在两种不同品系的野生型小鼠BALB/c和C57BL/6中并未出现这种效应。这一结果与肠杆菌科及蜱虫微生物群的其他细菌中广泛分布的α-1,3-半乳糖基转移酶基因以及可能的α-Gal相一致。有趣的是，吸食免疫C57BL/6小鼠的若虫体重显著高于吸食用假疫苗免疫的C57BL/6小鼠的蜱虫体重。我们的结果表明，抗蜱虫微生物群疫苗是用于实验性操控媒介微生物群、并有可能控制蜱虫及蜱传病原体的一种有前景的工具。
