鱼类抗刺激隐核虫感染的黏膜免疫研究进展

Advances in the research on mucosal immune response offish against Cryptocaryon irritans infection

刺激隐核虫是一种原生纤毛类寄生虫,可以感染几乎所有海水硬骨鱼类并导致死亡,给海水鱼类养殖业造成巨大经济损失。由于刺激隐核虫体表寄生的特性,使其成为研究鱼类黏膜免疫机制的良好病原模型,可为高效疫苗的研发提供理论依据。本文综述了鱼类抗刺激隐核虫感染的黏膜免疫研究进展,以期为开展海水鱼类抗刺激隐核虫感染的免疫防控措施研究提供理论支撑。已有研究表明,受刺激隐核虫感染后,斜带石斑鱼皮肤黏液或其培养上清液能使幼虫发生阻动,由皮肤中的抗体分泌细胞产生的特异性IgM抗体在抗寄生虫感染中发挥重要作用;同时在刺激隐核虫感染时,多种免疫细胞如NCC细胞、中性粒细胞等在寄生虫周围聚集,趋化因子以及趋化因子受体表达量在寄生虫感染部位上调,暗示其调节的免疫细胞也参与抗虫免疫;此外,研究发现黄斑蓝子鱼对刺激隐核虫具有天然抗性,其血清和皮肤黏液对刺激隐核虫幼虫和滋养体均具有杀灭作用,已从其血清中分离到一种天然抗虫蛋白—L-氨基酸氧化酶,为刺激隐核虫病的防控提供新的途径;在理论研究的基础上,通过免疫实验证实疫苗防控刺激隐核虫病是可行的。

Cryptocaryon irritans is an important parasite in mariculture fish,which can infect almost all kinds of marine bony fishes,causing fatal diseases and huge economic losses to marine aquaculture in China.Due to the property of living in the epidermis of the skin and gills,this makes it as good model to study the mucosal immunity of seawater fish,which are conducive to developing effective vaccine.In this paper,we reviewed the current progress of grouper(Epinephelus coioides)anti-C.irrians infection,which will provide the theoretical support for carrying out the immune prevention and control measures against C.irritans.The existing results show that after C.irritans infection,grouper skin mucous or its culture supernatant can immobilize the theronts,and specific IgM antibody anti-C.irritans was detected,which is produced by the antibody secreting cells in the skin and plays an important role in resistance to parasitic infections;We found many immune cells such as NCC cells,neutrophil cells around the parasites;meanwhile,the expression levels of some chemokines and chemokine receptors were significantly increased in the infection sites,implying that these immune cells may also involve resistance to parasite infection;In addition,we found that rabbitfish(Siganus oramin)was naturally resistant to C.irritans infection,the serum and skin mucous of which could kill the theronts and tomont of C.irritans.Next,a novel protein that is lethal to C.irritans was isolated from the serum of rabbitfish and which was identified as L-amino acid oxidase.Finally,by immune experiment,we proved the feasibility of vaccines for prevention and control of cryptocaryoniasis.