Respiratory burst activity of ayu (Plecoglossus altivelis) neutrophils : comparison with other fresh water fish

脊椎动物的中性粒细胞经历呼吸爆发活动（RBA）作为一种防御细菌感染的机制。我们在此报告，即使在健康状态下，ayu （Plecoglossus altivelis）也有异常高的RBA。肾脏（硬骨鱼的主要造血器官）和血液白细胞分别取自鱼、虹鳟（Oncorhynchus mykiss）、鲤鱼（Cyprinus carpio）、鳗鲡（Anguilla japonica）和池鱼（Hypomesus nipponensis）。中性粒细胞RBA经肉豆蔻酸佛波酯（PMA）刺激后，采用流式细胞术测定。阿渝鱼血液和肾脏中性粒细胞RBA含量均显著高于其他鱼类（如阿渝鱼血液中性粒细胞荧光强度约为鳟鱼和鲤鱼的3 ~ 7倍，阿渝鱼肾脏中性粒细胞荧光强度约为虹鳟、鲤鱼、鳗鱼和塘鱼的2 ~ 19倍）。在不同的年龄、位置和性成熟阶段，阿玉中性粒细胞的这一独特特性是不变的。为了了解阿育鱼中性粒细胞的这一独特特性，我们比较了阿育鱼和鲤鱼静止和炎症中性粒细胞的RBAs。腹腔注射灭菌诱导炎症反应。腹腔内可见炎性中性粒细胞。静息中性粒细胞取自非注射鱼的血液和肾脏。在鲤鱼中，炎症中性粒细胞的RBA远高于静止中性粒细胞。另一方面，在ayu中没有观察到显著差异。肾脏中中性粒细胞的RBA已经很高了。炎症过程没有进一步增强RBA。除PMA外，还使用其他刺激物（酶生酶、调理酶生酶和酶生酶处理血清）测量RBA。在这些刺激物的作用下，鲤鱼炎症中性粒细胞的RBA始终高于肾中性粒细胞的RBA。另一方面，在ayu中没有观察到显著差异。这些结果表明，即使在静息状态下，ayu中性粒细胞也具有自发激活ROS的特性。在这一点上，还不清楚为什么你有这样独特的中性粒细胞对ROS的产生。一种可能性是，高呼吸爆发活动与阿玉的寿命短（基本上是一年）有关。在如此短的生命周期中，自然激活的中性粒细胞的先天免疫可能比获得性免疫更重要。少

Neutrophils of vertebrates undergo a respiratory burst activity (RBA) as a defense mechanism against bacterial infections. We report here that ayu (Plecoglossus altivelis) have unusually high RBA even when they are in a healthy condition. Kidney (major hematopoietic organ in teleost fish) and blood leukocytes were obtained from ayu, rainbow trout (Oncorhynchus mykiss), carp (Cyprinus carpio), eel (Anguilla japonica), and pond smelt (Hypomesus nipponensis). Neutrophil RBA was measured by flow cytometry using dihydrorhodamine after stimulation with phorbol myristate acetate (PMA). The amount of RBA of neutrophils from both blood and kidney was significantly higher in ayu than in the other species (e.g., the fluorescence intensity of ayu blood neutrophils was about 3 to 7 times higher than that from trout and carp, and that of ayu kidney neutrophils was 2 to 19 times higher than that of rainbow-trout, carp, eel, and pond-smelt). This unique character of ayu neutrophils was invariable even … More at different ages, locations, and sex-maturation stages.To understand this unique character of ayu neutrophils, the RBAs of resting and inflammatory neutrophils of ayu and carp were compared. Inflammation was induced in the peritoneal cavity by injecting killed-bacteria. The inflammatory neutrophils were obtained from peritoneal cavity. Resting neutrophils were obtained from blood and kidney of non-injected fish.In carp, the RBA of inflammatory neutrophils was much higher than that of resting neutrophils. On the other hand, in ayu no significant difference was observed. The RBA of neutrophils was already high in the kidney stock. The process of inflammation did not further enhance RBA. In addition to PMA, other stimulants (zymosan, opsonized-zymosan, and zymosan treated serum) were used to measure RBA. Even with these stimulants, the RBA of inflammatory neutrophils was always higher than that of kidney neutrophils in carp. On the other hand, no significant difference was observed in ayu. These results indicate ayu neutrophils have spontaneously activated characteristics with the respect to the ROS generation even in the resting state.At this point, it is not clear why ayu have such unique neutrophils with respect to the ROS generation. One possibility is that the high respiratory burst activity is related to the short life span of ayu (essentially one year). With such a short life span, it is likely that the innate immunity by spontaneously activated neutrophils is more important than acquired immunity. Less