Immunostimulation of shrimp through oral administration of silkworm pupae expressing VP15 against WSSV

• Published in: Fish & shellfish immunology Vol. 128; pp. 157 - 167
• Main Authors: Boonyakida, Jirayu, Nakanishi, Takafumi, Satoh, Jun, Shimahara, Yoshiko, Mekata, Tohru, Park, Enoch Y.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2022
• Subjects: Marsupenaeus japonicus; Oral administration; Silkworm pupa; VP15; White spot syndrome virus; White spot syndrome virus; Silkworm pupa; VP15; Marsupenaeus japonicus; Oral administration
• ISSN: 1050-4648; 1095-9947
• DOI: 10.1016/j.fsi.2022.07.043

White spot syndrome virus (WSSV) is one of the most concerning pathogens in penaeid shrimp and can cause severe loss in shrimp aquaculture worldwide. Among the WSSV structural proteins, VP15, a DNA-binding protein located in the WSSV nucleocapsid, is an antiviral protein candidate to protect kuruma shrimp (Marsupenaeus japonicus) from WSSV infection. We identified that the truncated VP15, VP15(26–57), is responsible for the protective effect against the WSSV. This study attempts to develop an immunizing agent against WSSV using silkworm pupa as a delivery vector through oral administration. The VP15, VP15(26–57), and SR11 peptide derived from VP15(26–57) were expressed in silkworm pupae. Oral administration of feed mixed with the powdered pupae that expressed VP15-derived constructs enhanced the survivability of kuruma shrimp with an overall relative percent survival (RPS) higher than 70%. There is no death for the group receiving pupa/VP15(26–57), and the RPS is 100%. In addition, we also investigated the relative mRNA expression levels of immune-related genes by qPCR at different time points. Our results indicate that the oral administration of pupa/VP15-derived products could provide a high protective effect against WSSV and be a practical approach for controlling WSSV in aquaculture. [Display omitted] •VP15, a major WSSV structural protein, was a candidate to protect kuruma shrimp against WSSV infection.•The VP15 and VP15-derived SR11 peptide were expressed in silkworm pupa.•Pupae expressing VP15-derived products enhanced the immune response of kuruma shrimp.•Oral administration of pupa/VP15-derived products could provide a high protective effect against WSSV.