Abstract

Two monoclonal antibodies (MAbs) recognizing envelope proteins of the white spot syndrome virus (WSSV), 6E1 against VP28 and 3E8 against VP19, were applied to demonstrate their neutralizing ability to this virus by using both in vitro and in vivo assays. Mixtures of MAb 6E1 with virus filtrate were inoculated into the primary explant monolayer culture derived from the lymphoid Oka organs of Penaeus monodon. Mab was likely to neutralize the infectivity of virus to monolayer since cytopathic effects were apparently blocked in experiment group. WSSV was titrated using Blue-Cell ELISA and the neutralizing index was calculated to be 6.90 for 6EI and 5.83 for 3E8. Neutralized virus fluids injected intramuscularly into post larvae of P. monodon. The shrimp in the positive control, which were injected with WSSV only showed an increasing mortality and a 100% mortality was reached at day 34, whereas no shrimp died in the negative control. The mortality for 6E1 was 6.7% and for 3E8 was 13.3%. These results suggest that Mabs recognizing the WSSV envelope proteins could neutralize viral infectivity to both cultured cells and shrimp.

中文摘要

本研究利用辨識白斑病病毒套膜蛋白質VP28 和VP19 之兩株專一性單株抗體－6E1 和3E8，經由體外培養和活體實驗兩系統測試其對病毒之中和作用。體外系統實驗係先將草蝦淋巴器官組織塊培養出初級培養之單層細胞，再接種與6E1 反應過之病毒液，結果發現實驗組中細胞病變效應被顯著遏止，顯示抗體可中和病毒對細胞之感染力。以Blue-Cell ELISA 滴定中和反應前後之病毒液力價並計算抗體之中和指數，6EI 的指數為6.90 而3E8 的為5.83。活體系統實驗是將抗體中和後之病毒液注射入草蝦後期幼生之腹部肌肉，飼養觀察35 日；發現注射病毒液之陽性對照組的死亡率持續上升而在第34 日達到100%，陰性對照組的死亡率維持於0，感染經抗體6E1 或3E8 中和之病毒液，其累積死亡率分別為6.7% 及13.3%。本研究顯示辨識白斑病病毒套膜蛋白質之單株抗體可中和此病毒對體外初級培養淋巴細胞及對蝦體之感染力。

Keyword: White spot syndrome virus, WSSV, Mabs, Neutralization, Primary culture