Fisk Elis A, Leonard Cassie J, Rosche Kristin L, Ramirez-Zepp Elisabeth, Abbott Jeffrey R, Owen Jeb P, Shaw Dana K
Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, USA.
Washington Animal Disease Diagnostic Laboratory, Washington State University, Pullman, Washington, USA.
Infect Immun. 2025 Oct 14;93(10):e0024625. doi: 10.1128/iai.00246-25. Epub 2025 Sep 3.
Ticks are obligate hematophagous parasites and pathogen vectors responsible for morbidity and mortality worldwide. is a vector for at least seven pathogens relevant to human and animal health, including the Lyme disease microbe, , and the causative agent of anaplasmosis, . Tick-host interactions affect the maintenance of tick-borne pathogens in a population. Here, we report that repeated larval infestations on the wild host species lead to immune-mediated rejection of the tick, a phenomenon termed acquired tick resistance (ATR). On previously infested mice, we observed that larval feeding success was reduced by over 50%, and fed larvae had decreased blood meal weights compared to larvae fed on naïve hosts. Over sequential infestations, mice exhibited increasingly severe inflammation at tick bite sites characterized by an influx of basophils, eosinophils, neutrophils, and T lymphocytes. Larvae fed on sensitized mice ingested higher quantities of host leukocytes when compared to ticks fed on naïve hosts, which rarely ingested nucleated cells. When challenged with or , larvae fed on sensitized mice ingested more bacteria. Altogether, we demonstrate that reservoir host species develop ATR against larval , which reduces tick feeding success and affects pathogen ingestion by larvae. These results indicate that ATR could impact population dynamics, prevalence of infected ticks, and pathogen circulation in the wild.
蜱是专性吸血寄生虫和病原体传播媒介，在全球范围内导致发病和死亡。蜱是至少七种与人类和动物健康相关病原体的传播媒介，包括莱姆病微生物、伯氏疏螺旋体，以及无形体病的病原体嗜吞噬细胞无形体。蜱与宿主的相互作用影响蜱传病原体在种群中的维持。在此，我们报告，对野生宿主物种白足鼠进行多次幼蜱感染会导致蜱受到免疫介导的排斥，这一现象称为获得性蜱抗性（ATR）。在先前已感染的小鼠身上，我们观察到幼蜱的取食成功率降低了50%以上，与在未感染宿主上取食的幼蜱相比，已取食的幼蜱血餐重量有所下降。在连续感染过程中，小鼠在蜱叮咬部位表现出越来越严重的炎症，其特征是嗜碱性粒细胞、嗜酸性粒细胞、中性粒细胞和T淋巴细胞的大量涌入。与在未感染宿主上取食的蜱相比，在致敏小鼠上取食的幼蜱摄取了更多的宿主白细胞，而在未感染宿主上取食的蜱很少摄取有核细胞。当用伯氏疏螺旋体或嗜吞噬细胞无形体进行攻击时，在致敏小鼠上取食的幼蜱摄取了更多的细菌。总之，我们证明储存宿主物种对白足鼠幼蜱产生了ATR，这降低了蜱的取食成功率并影响幼蜱对病原体的摄取。这些结果表明，ATR可能会影响白足鼠的种群动态、感染蜱的流行率以及病原体在野外的传播。
