Department of Fisheries & Oceans Canada, Gulf Fisheries Center, Moncton, NB, Canada.
Mol Immunol. 2012 Jun;51(2):197-209. doi: 10.1016/j.molimm.2012.03.021. Epub 2012 Apr 3.
Following an infection with a specific pathogen, the acquired immune system of many teleostean fish, including salmonids, is known to retain a specific memory of the infectious agent, which protects the host against subsequent infections. For example, Atlantic salmon (Salmo salar) that have survived an infection with a low-virulence infectious salmon anemia virus (ISAV) isolate are less susceptible to subsequent ISAV infections. A greater understanding of the mechanisms and immunological components involved in this acquired protection against ISAV is fundamental for the development of efficacious vaccines and treatments against this pathogen. To better understand the immunity components involved in this observed resistance, we have used an Atlantic salmon DNA microarray to study the global gene expression responses of preexposed Atlantic salmon (fish having survived an infection with a low-virulence ISAV isolate) during the course of a secondary infection, 18 months later, with a high-virulence ISAV isolate. We present global gene expression patterns in both preexposed and naïve fish, following exposure by either cohabitation with infected fish or by direct intra-peritoneal injection of a high-virulence ISAV isolate. Our results show a clear reduction of ISAV viral loads in head-kidney of secondary infected fish compared to primary infected fish. Further, we note a lower-expression of many antiviral innate immunity genes in the secondary infected fish, such as the interferon induced GTP-binding protein Mx, CC-chemokine 19 and signal transducer and activator of transcription 1 (STAT 1), as well as MHC class I antigen presentation involved genes. Potential acquired immunity genes such as GILT, leukocyte antigen transcript CD37 and Ig mu chain C region membrane-bound form were observed to be over-expressed in secondary infected fish. The observed differential gene expression profile in secondary and primary infected fish head-kidney provides great insight into immunity components involved during primary and secondary ISAV infection.
在感染特定病原体后，包括鲑鱼在内的许多硬骨鱼类的获得性免疫系统被认为对感染原具有特定的记忆，从而保护宿主免受随后的感染。例如，曾感染低毒传染性鲑鱼贫血病毒（ISAV）分离株的大西洋鲑（Salmo salar）对随后的 ISAV 感染的易感性降低。更深入地了解这种针对 ISAV 的获得性保护所涉及的机制和免疫成分对于开发针对这种病原体的有效疫苗和治疗方法至关重要。为了更好地了解这种观察到的抗性所涉及的免疫成分，我们使用大西洋鲑鱼 DNA 微阵列研究了在第二次感染高毒 ISAV 分离株 18 个月后，先前暴露于低毒 ISAV 分离株的大西洋鲑鱼（曾感染过低毒 ISAV 分离株的鱼）在二次感染过程中的全基因表达反应。我们展示了在接触感染鱼或直接腹腔内注射高毒 ISAV 分离株后，预先暴露和未暴露的鱼的全基因表达模式。我们的结果表明，与初次感染鱼相比，二次感染鱼的头肾中的 ISAV 病毒载量明显降低。此外，我们注意到二次感染鱼中许多抗病毒先天免疫基因的表达水平较低，例如干扰素诱导的 GTP 结合蛋白 Mx、CC-趋化因子 19 和信号转导和转录激活因子 1（STAT 1），以及 MHC Ⅰ类抗原呈递相关基因。还观察到一些潜在的获得性免疫基因，如 GILT、白细胞抗原转录物 CD37 和 Ig mu 链 C 区膜结合形式，在二次感染鱼中过表达。在二次和初次感染鱼的头肾中观察到的差异基因表达谱为初次和二次 ISAV 感染期间涉及的免疫成分提供了深入的了解。
