Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Phyathai Road, Bangkok 10330, Thailand.
Dev Comp Immunol. 2010 Oct;34(10):1101-8. doi: 10.1016/j.dci.2010.06.001. Epub 2010 Jun 15.
A five-domain Kazal-type serine proteinase inhibitor, SPIPm2, from Penaeus monodon has recently been implicated in antiviral responses for it is up-regulated upon viral infection and needs further studies. The SPIPm2 genomic gene was composed of seven exons and six introns. The genomic DNA segments coding for each Kazal domain were separated by introns of variable lengths supporting the hypothesis of gene duplication in the Kazal-type gene family. RT-PCR and Western blot analysis revealed that the SPIPm2 transcript and its five-domain protein product were expressed mainly in the hemocytes and less in gill, heart and antennal gland. Upon white spot syndrome virus (WSSV) infection, the SPIPm2 was only detected in the hemocytes and plasma. Immunocytochemical study of P. monodon hemocytes showed that the percentage of SPIPm2-producing hemocytes was reduced by about half after WSSV infection. Quantitative RT-PCR revealed further that the SPIPm2 was up-regulated early in the hemocytes of WSSV-infected shrimp and gradually reduced as the infection progressed. Injection of the recombinant SPIPm2 (rSPIPm2) prior to WSSV injection resulted in a significant inhibition of WSSV replication. The rSPIPm2 injection also prolonged the mortality rate of WSSV-infected shrimp. Therefore, the SPIPm2 was involved in the innate immunity against WSSV infection in shrimp.
一种来自凡纳滨对虾的五域 Kazal 型丝氨酸蛋白酶抑制剂 SPIPm2，最近被认为与抗病毒反应有关，因为它在病毒感染时被上调，需要进一步研究。SPIPm2 基因的基因组由七个外显子和六个内含子组成。编码每个 Kazal 结构域的基因组 DNA 片段由不同长度的内含子分隔，这支持了 Kazal 型基因家族中基因复制的假说。RT-PCR 和 Western blot 分析显示，SPIPm2 转录本及其五域蛋白产物主要在血细胞中表达，在鳃、心脏和触角腺中表达较少。在白斑综合征病毒 (WSSV) 感染后，仅在血细胞和血浆中检测到 SPIPm2。对凡纳滨对虾血细胞的免疫细胞化学研究表明，WSSV 感染后 SPIPm2 产生的血细胞百分比减少了约一半。定量 RT-PCR 进一步表明，SPIPm2 在 WSSV 感染对虾的血细胞中早期上调，并随着感染的进展逐渐减少。在注射 WSSV 之前注射重组 SPIPm2 (rSPIPm2) 可显著抑制 WSSV 的复制。rSPIPm2 的注射也延长了 WSSV 感染对虾的死亡率。因此，SPIPm2 参与了虾类对 WSSV 感染的先天免疫。
