Wade-Evans A M, Pullen L, Hamblin C, O'Hara R, Burroughs J N, Mertens P P
Institute for Animal Health, Pirbright Laboratory, Working, Surrey, UK.
J Gen Virol. 1997 Jul;78 ( Pt 7):1611-6. doi: 10.1099/0022-1317-78-7-1611.
An established mouse model was used to evaluate the effectiveness of the major outer core protein of African horsesickness virus (AHSV), VP7, as a subunit vaccine. Adult female BALB/c mice were immunized with VP7 crystals purified from BHK cells infected with AHSV serotype 9 (AHSV-9), using three inoculations in Freund's adjuvant. Eighty to one hundred per cent of the immunized mice were protected against a heterologous challenge with a known lethal dose of AHSV-7. The protected immunized mice did not develop any clinical signs characteristic of virulent AHSV infection in this model during the study. In contrast, 80-100% mortality was observed in the non-immunized mice that received the same challenge virus. Subsequent studies indicated that a single inoculation of 1.5 micrograms purified AHSV VP7 in Freund's complete adjuvant was sufficient to protect at least 90% of mice from AHSV-7 challenge. If the antigen was presented in the absence of Freund's complete adjuvant, 70% of the mice were still protected by one inoculation of VP7 crystals. Titres of circulating antibody against AHSV VP7, determined by competitive ELISA, did not appear to correlate with protection and passive antibody transfer from immunized BALB/c mice failed to protect syngeneic recipients from AHSV-7 challenge. Therefore, the observed protection is unlikely to be due to an antibody-mediated immune response. The number of viraemic mice and the duration of viraemia post-challenge was significantly reduced in vaccinated mice compared to non-vaccinated controls. However, the levels of viraemia were similar.
使用已建立的小鼠模型来评估非洲马瘟病毒（AHSV）的主要外核心蛋白VP7作为亚单位疫苗的有效性。成年雌性BALB/c小鼠用从感染了AHSV血清型9（AHSV-9）的BHK细胞中纯化的VP7晶体进行免疫，在弗氏佐剂中进行三次接种。80%至100%的免疫小鼠在受到已知致死剂量的AHSV-7的异源攻击时得到保护。在研究期间，受到保护的免疫小鼠在该模型中未出现任何强毒AHSV感染的特征性临床症状。相比之下，接受相同攻击病毒的未免疫小鼠的死亡率为80%-100%。后续研究表明，在弗氏完全佐剂中单次接种1.5微克纯化的AHSV VP7足以保护至少90%的小鼠免受AHSV-7攻击。如果在没有弗氏完全佐剂的情况下呈现抗原，70%的小鼠通过单次接种VP7晶体仍得到保护。通过竞争ELISA测定的针对AHSV VP7的循环抗体滴度似乎与保护作用无关，并且来自免疫的BALB/c小鼠的被动抗体转移未能保护同基因受体免受AHSV-7攻击。因此，观察到的保护作用不太可能是由于抗体介导的免疫反应。与未接种疫苗的对照组相比，接种疫苗的小鼠中病毒血症小鼠的数量和攻击后病毒血症的持续时间显著减少。然而，病毒血症水平相似。
