White spot syndrome virus (WSSV) inactivation in Penaeus japonicus using purified monoclonal antibody targeting viral envelope protein

White spot syndrome virus (WSSV) infection has cau9sed huge amount of losses in the shrimp aquaculture industry. In search for potential solutions to circumvent this problem, several strategies are being exploited, among which is the application of neutralizing antibodies to control WSSV infection. In this study, a monoclonal antibody was developed and its neutralizing activity was evaluated both in vivo and in vitro. The monoclonal antibody has affinity to VP28, a viral envelope protein. In vivo neutralization assay showed 80% survival in shrimps injected with WSSV at a dilution of 1 × 10− 3 pre-incubated with purified immunoglobulin (IgG) of MAb 216. However, at higher virus concentrations (1 × 10− 1 and 1 × 10− 2 virus stock dilutions), MAb 216 was not able to neutralize WSSV. This suggested that the neutralization effect was concentration-dependent. Results from in vitro neutralization studies in shrimp primary lymphoid cell culture showed only diminished infectivity. WSSV was not detected in primary lymphoid cells after 16 and 24 h p.i., however, after 48 h p.i. the virus was able to proliferate and detected by PCR analysis. These results demonstrated that MAb against viral envelope protein (VP28) is effective in protection of P. japonicus from WSSV and support previous reports on the involvement of VP28 in the initial stages of infection. Also, MAb 216 offers to be a valuable tool in the development of new strategies to control WSSV infection.