Section of Parasitology and Aquatic Pathobiology, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.
PLoS One. 2018 Sep 11;13(9):e0203297. doi: 10.1371/journal.pone.0203297. eCollection 2018.
The protective immune response in zebrafish (Danio rerio) against the parasitic ciliate Ichthyophthirius multifiliis, targeting host skin, fins and gills, comprises an accelerated and manifold elevated immunoglobulin gene expression as well as a significantly elevated number of neutrophils at infected sites. Experimental fish were subjected to a primary I. multifiliis infection followed by a series of secondary exposures before they were challenged by a high dosage of infective theronts. Immunized fish responded immediately with a protective response suggesting existence of immunological memory whereas fish exposed to the parasite for the first time obtained a marked infection. The primary response to infection was dominated by expression of genes encoding acute phase reactants and inflammatory cytokines as well as recruitment of neutrophils at infected locations. Immunized fish showed a significantly upregulated immunoglobulin gene expression following challenge, which indicates existence of a secondary response effected by antibodies. Both responses induced a significantly elevated expression of the Th2 signature cytokine Il13. The increased presence of neutrophils in immunized fish suggests that innate cell mediated immunity supplements or influence the protective response against the parasite.
斑马鱼（Danio rerio）针对寄生纤毛虫小瓜虫（Ichthyophthirius multifiliis）的保护性免疫反应，针对宿主的皮肤、鳍和鳃，包括加速和多种免疫球蛋白基因表达的升高，以及感染部位中性粒细胞数量的显著升高。实验鱼在受到高剂量感染性游孢子的挑战之前，先经历了一次小瓜虫的原发性感染和一系列继发性暴露。免疫鱼立即做出了保护性反应，表明存在免疫记忆，而第一次接触寄生虫的鱼则获得了明显的感染。感染的主要反应是急性反应蛋白和炎症细胞因子的基因表达以及感染部位中性粒细胞的募集。免疫鱼在受到挑战后表现出显著上调的免疫球蛋白基因表达，这表明存在由抗体介导的二次反应。这两种反应都诱导了 Th2 特征细胞因子 Il13 的表达显著增加。免疫鱼中中性粒细胞的增加表明，先天细胞介导的免疫补充或影响了对寄生虫的保护反应。
