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)，作为抵抗细菌感染的一种防御机制。我们在这里报道，即使在健康的情况下，AYU(Plecoglossus Altivelis)也有异常高的RBA。肾(硬骨鱼的主要造血器官)和血白细胞来自于鲤鱼、虹鲑鱼、鲤鱼、鳗鱼和池鱼。经佛波醇酯(PMA)刺激后，用双氢罗丹明流式细胞仪检测中性粒细胞RBA。中性粒细胞在血液和肾脏中的含量显著高于其他物种(例如，中性粒细胞的荧光强度是鲑鱼和鲤鱼的3~7倍，肾中性粒细胞的荧光强度是虹鱼、鲤鱼、鳗鱼和池鱼的2~19倍)。中性粒细胞的这一独特特征即使在…中也是不变的为了了解阿育中性粒细胞的这一独特特征，我们比较了阿育和鲤鱼的静息和炎性中性粒细胞的RBAs。通过注射灭活细菌在腹膜腔内诱导炎症。从腹膜腔取炎性中性粒细胞。未注射的鲤鱼血液和肾脏中均可获得静止性中性粒细胞，鲤鱼体内炎性中性粒细胞的RBA值明显高于静止期中性粒细胞。另一方面，在雅玉没有观察到显著的差异。中性粒细胞在肾脏中的含量已经很高了。炎症过程并未进一步加强澳洲央行。除PMA外，还使用其他刺激剂(酵母多糖、调理酵母多糖和酵母多糖处理的血清)来测定RBA值。即使在这些刺激剂的作用下，鲤鱼体内炎性中性粒细胞的RBA值始终高于肾中性粒细胞。另一方面，在AYU中没有观察到显著的差异。这些结果表明，即使在静息状态下，AYU中性粒细胞也具有与ROS生成相关的自发激活特征，目前尚不清楚为什么AYU相对于ROS生成具有如此独特的中性粒细胞。一种可能性是，高呼吸爆发活动与阿育的短寿命(基本上是一年)有关。人的寿命如此之短，自然激活的中性粒细胞的先天免疫很可能比获得性免疫更重要。较少

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