Norte dos Santos C C, Adams M B, Leef M J, Nowak B F
National Centre for Marine Conservation and Resource Sustainability, University of Tasmania, Locked Bag 1370, Launceston, Tasmania 7250, Australia.
National Centre for Marine Conservation and Resource Sustainability, University of Tasmania, Locked Bag 1370, Launceston, Tasmania 7250, Australia.
Fish Shellfish Immunol. 2014 Dec;41(2):600-7. doi: 10.1016/j.fsi.2014.10.003. Epub 2014 Oct 17.
The interbranchial lymphoid tissue (ILT) was recently described in the gills of salmonids. This study examined changes in the ILT during a parasitic infection in marine environment, using amoebic gill disease (AGD) as a model. Atlantic salmon (Salmo salar) experimentally infected with Neoparamoeba perurans were sampled at 0, 3, 7, 14 and 28 days post challenge. Transversal sections of three areas of the gills (dorsal, medial and ventral) were histologically assessed for morphological and cellular changes. AGD induced morphological changes and a cellular response in the ILT of affected fish. These changes included a significant increase in the ILT surface area in fish 28 days after AGD challenge, compared to control fish at the same time point. The length of the ILT increased significantly 28 days post exposure in the dorsal area of the gill arch in the fish affected by AGD. The lymphocyte density of the ILT increased after AGD challenge, peaking at 7 days post exposure; however, by 28 days post exposure, a reduction of lymphocyte density to values close to pre-infection levels was observed. PCNA immunostaining revealed that epithelial hyperplasia was the most likely factor contributing to the ILT enlargement in the affected fish.
鳃间淋巴组织（ILT）最近在鲑科鱼类的鳃中被描述。本研究以阿米巴鳃病（AGD）为模型，研究了海洋环境中寄生虫感染期间ILT的变化。在攻毒后0、3、7、14和28天对实验感染秘鲁新变形虫的大西洋鲑（Salmo salar）进行采样。对鳃的三个区域（背侧、内侧和腹侧）的横向切片进行组织学评估，以观察形态和细胞变化。AGD在受影响鱼类的ILT中诱导了形态变化和细胞反应。这些变化包括与同一时间点的对照鱼相比，AGD攻毒28天后鱼类的ILT表面积显著增加。在受AGD影响的鱼类鳃弓背侧区域，暴露后28天ILT的长度显著增加。AGD攻毒后ILT的淋巴细胞密度增加，在暴露后7天达到峰值；然而，在暴露后28天，观察到淋巴细胞密度降低至接近感染前水平的值。PCNA免疫染色显示，上皮增生最有可能是导致受影响鱼类ILT增大的因素。
