Seemann Frauke, Peterson Drew Ryan, Chiang Michael Wai Lun, Au Doris Wai Ting
State Key Laboratory in Marine Pollution, Department of Biology and Chemistry, City University of Hong Kong, Hong Kong Special Administrative Region.
State Key Laboratory in Marine Pollution, Department of Biology and Chemistry, City University of Hong Kong, Hong Kong Special Administrative Region.
Comp Biochem Physiol C Toxicol Pharmacol. 2017 Sep;199:81-89. doi: 10.1016/j.cbpc.2017.03.010. Epub 2017 Mar 24.
Environmentally induced alterations of the immune system during sensitive developmental stages may manifest as abnormalities in immune organ configuration and/or immune cell differentiation. These not only render the early life stages more vulnerable to pathogens, but may also affect the adult immune competence. Knowledge of these sensitive periods in fish would provide an important prognostic/diagnostic tool for aquatic risk assessment of immunotoxicants. The marine medaka Oryzias melastigma is an emerging seawater fish model for immunotoxicology. Here, the presence and onset of four potentially sensitive periods during the development of innate and adaptive cellular immune defence were revealed in O. melastigma: 1.) initiation of phagocyte differentiation, 2.) migration and expansion of lymphoid progenitor cells, 3.) colonization of immune organs through lymphocyte progenitors and 4.) establishment of immune competence in the thymus. By using an established bacterial resistance assay for O. melastigma, larval immune competence (from newly hatched 1dph to 14dph) was found concomitantly increased with advanced thymus development and the presence of mature T-lymphocytes. A comparison between the marine O. melastigma and the freshwater counterpart Oryzias latipes disclosed a disparity in the T-lymphocyte maturation pattern, resulting in differences in the length of T-lymphocyte maturation. The results shed light on a potential difference between seawater and freshwater medaka in their sensitivity to environmental immunotoxicants. Further, medaka immune system development was compared and contrasted to economically important fish. The present study has provided a strong scientific basis for advanced investigation of critical windows for immune system development in fish.
在敏感发育阶段,环境诱导的免疫系统改变可能表现为免疫器官结构和/或免疫细胞分化异常。这些不仅使生命早期阶段更容易受到病原体的侵害,还可能影响成年后的免疫能力。了解鱼类的这些敏感期将为免疫毒性物质的水生风险评估提供重要的预后/诊断工具。海洋青鳉(Oryzias melastigma)是一种新兴的海水鱼类免疫毒理学模型。在此,揭示了海洋青鳉先天和适应性细胞免疫防御发育过程中四个潜在敏感期的存在和起始时间:1.)吞噬细胞分化的起始;2.)淋巴祖细胞的迁移和扩增;3.)淋巴细胞祖细胞对免疫器官的定植;4.)胸腺中免疫能力的建立。通过使用已建立的针对海洋青鳉的细菌抗性测定法,发现幼虫免疫能力(从新孵化的1日龄幼体到14日龄幼体)随着胸腺发育的推进和成熟T淋巴细胞的存在而相应增加。对海洋青鳉和淡水青鳉(Oryzias latipes)进行比较发现,它们在T淋巴细胞成熟模式上存在差异,导致T淋巴细胞成熟时间长度不同。这些结果揭示了海水青鳉和淡水青鳉在对环境免疫毒性物质敏感性方面的潜在差异。此外,还将青鳉的免疫系统发育与具有经济重要性的鱼类进行了比较和对比。本研究为深入研究鱼类免疫系统发育的关键窗口期提供了坚实的科学依据。