Faculty of Bioscience Engineering, Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Rozier 44, Gent 9000, Belgium.
Fish Shellfish Immunol. 2011 Jul;31(1):134-41. doi: 10.1016/j.fsi.2011.04.008. Epub 2011 May 1.
Like other invertebrates, the brine shrimp Artemia franciscana relies solely on innate immunity, which by definition lacks adaptive characteristics, to combat against invading pathogens. One of the innate mechanisms is melanisation of bacteria mediated by the activation of the prophenoloxidase (proPO) system. The 70 kDa heat shock proteins (Hsp70) derived from either prokaryote (Escherichia coli) or eukaryote (Artemia), well conserved and immune-dominant molecules, protect Artemia against Vibrio campbellii. However, the molecular mechanisms by which these proteins protect Artemia against Vibrio campbellii infection are unknown. Here we demonstrated that feeding gnotobiotically grown Artemia with either Artemia Hsp70 or the E. coli Hsp70 equivalent DnaK, each overproduced in E. coli, followed by V. campbellii challenge enhanced the proPO system, at both mRNA and protein activity levels. Additionally, the Artemia fed with these proteins survived well in a Vibrio challenge assay. These results indicated that Hsp70s derived from either prokaryotic or eukaryotic sources generate protective immunity in the crustacean Artemia against V. campbellii infection by priming the proPO system. This is apparently the first in vivo report on priming activity of Hsp70 in an invertebrate.
与其他无脊椎动物一样，卤虫（Artemia franciscana）仅依赖于先天免疫来对抗入侵的病原体，而先天免疫定义上缺乏适应性特征。先天免疫机制之一是通过酚氧化酶原（proPO）系统的激活来介导细菌黑化。来源于原核生物（大肠杆菌）或真核生物（卤虫）的 70 kDa 热休克蛋白（Hsp70）是高度保守且具有免疫优势的分子，可保护卤虫免受鳗弧菌的侵害。然而，这些蛋白质保护卤虫免受鳗弧菌感染的分子机制尚不清楚。在这里，我们证明了通过在大肠杆菌中过表达，分别用大肠杆菌来源的 DnaK 或卤虫来源的 Hsp70 喂养无菌培养的卤虫，随后用鳗弧菌进行攻毒，可以在 mRNA 和蛋白活性水平上增强 proPO 系统。此外，用这些蛋白质喂养的卤虫在鳗弧菌攻毒试验中存活良好。这些结果表明，来源于原核生物或真核生物的 Hsp70 通过激活 proPO 系统，为甲壳类卤虫抵御鳗弧菌感染提供了保护性免疫。这显然是首例关于 Hsp70 在无脊椎动物中引发作用的体内报告。
