Domain 2 of a Kazal serine proteinase inhibitor SPIPm2 from Penaeus monodon possesses antiviral activity against WSSV

Abstract

A 5-domain Kazal type serine proteinase inhibitor SPI. Pm2 from Penaeus monodon is involved in innate immune defense against white spot syndrome virus (WSSV). To test which domains were involved, the 5 domains of SPI. Pm2 were over-expressed and tested against WSSV infection. By using hemocyte primary cell culture treated with each recombinant SPI. Pm2 domain along with WSSV, the expression of WSSV early genes ie1, WSV477 and late gene VP28 were substantially reduced as compared to other domains when the recombinant domain 2, rSPI. Pm2D2, was used. Injecting the WSSV along with rSPI. Pm2D2 but not with other domains caused delay in mortality rate of the infected shrimp. The results indicate that the SPI. Pm2D2 possesses strong antiviral activity and, hence, contributes predominantly to the antiviral activity of SPI. Pm2. © 2014 Elsevier Ltd.