Protective immunity against iridovirus disease in mandarin fish, induced by recombinant major capsid protein of infectious spleen and kidney necrosis virus

► The major capsid protein (MCP) gene of ISKNV from mandarin fish, Siniperca chuatsi was cloned and expressed. ► Rabbit antiserum against MCP could react with the spleen and kidney of diseased mandarin fish. ► Specific antibodies and lymphocyte proliferation were induced by recombinant MCP at different dose and the values of MCP50 group were higher than the other two groups. ► Fish of MCP50 group showed significantly greater survival than the others after challenge infection with ISKNV.