Seppola Marit, Mikkelsen Helene, Johansen Audny, Steiro Kari, Myrnes Bjørnar, Nilsen Inge W
Norwegian College of Fishery Science, The Arctic University of Norway, P.O. Box 6050, 9037 Tromsø, Norway.
The Northern Norway Regional Health Authority, P.O. Box 6426, 9294 Tromsø, Norway.
Fish Shellfish Immunol. 2015 May;44(1):66-78. doi: 10.1016/j.fsi.2015.01.018. Epub 2015 Feb 2.
Phagocyte recognition of lipopolysaccharide (LPS) is an early key event for triggering the host innate immune response necessary for clearance of invading bacteria. The ability of fishes to recognise LPS has been questioned as contradictory results have been presented. We show here that monocyte/macrophage cultures from Atlantic cod (Gadus morhua) and Atlantic salmon (Salmo salar) respond with an increased expression of inflammatory and antibacterial genes to both crude and ultrapure Escherichia coli LPS. Crude LPS produces higher induction than the ultrapure LPS type in both species in vitro as well as in vivo in cod injected with LPS. Crude LPS gave, in contrast to ultrapure LPS, an additional weak up-regulation of antiviral genes in salmon macrophages, most likely because of contaminants in the LPS preparation. Increased levels of chicken (c)-type lysozyme transcripts and enzyme activity were measured in salmon macrophages following ultrapure LPS stimulation demonstrating not only increased transcription but also translation. Simultaneous use and even pre-treatment with bovine sera suppressed the LPS-induced expression thereby reflecting the presence of transcription inhibitory components in sera. Together, these findings show that both cod and salmon recognise LPS per se and that the observed induction is highly dependent on the absence of sera.
吞噬细胞对脂多糖（LPS）的识别是触发宿主先天性免疫反应的早期关键事件，这对于清除入侵细菌至关重要。鱼类识别LPS的能力一直受到质疑，因为出现了相互矛盾的结果。我们在此表明，来自大西洋鳕鱼（Gadus morhua）和大西洋鲑鱼（Salmo salar）的单核细胞/巨噬细胞培养物对粗制和超纯大肠杆菌LPS的反应是炎症和抗菌基因表达增加。在体外以及在注射LPS的鳕鱼体内，粗制LPS在这两个物种中产生的诱导作用均高于超纯LPS类型。与超纯LPS相比，粗制LPS在鲑鱼巨噬细胞中还使抗病毒基因有额外的微弱上调，这很可能是由于LPS制剂中的污染物所致。在超纯LPS刺激后，在鲑鱼巨噬细胞中检测到鸡（c）型溶菌酶转录本水平和酶活性增加，这不仅表明转录增加，还表明翻译增加。同时使用甚至用牛血清预处理都会抑制LPS诱导的表达，从而反映出血清中存在转录抑制成分。总之，这些发现表明鳕鱼和鲑鱼都能识别LPS本身，并且观察到的诱导作用高度依赖于血清的缺失。
