Huismans H, van der Walt N T, Cloete M, Erasmus B J
Virology. 1987 Mar;157(1):172-9. doi: 10.1016/0042-6822(87)90326-6.
A method to purify the neutralization specific antigen of bluetongue virus P2 in large amounts has been developed. The purified protein is free from virus-specified or cellular contaminants and its immunological specificity has been preserved. The purification is based on the observation that protein P2 can be dissociated from the virion by treatment with monovalent or divalent salts. The salt concentration required to solubilize the outer capsid proteins is pH dependent and in general decreases with a decrease in pH. P2 purified by extraction from polyacrylamide gels does not induce immune-precipitating or neutralizing antibodies. The response against P5, on the other hand, is much less conformational dependent and P5 purified from gels readily induces P5-precipitating antibodies in rabbits. These antibodies do not neutralize the virus. Purified P2, immunoabsorbed with anticore serum to remove trace amounts of P7, was injected into sheep. An initial dose of 50 micrograms of P2 was sufficient to induce P2-precipitating antibodies as well as neutralizing and hemagglutination-inhibiting antibodies. These sheep were fully protected against challenge with a virulent strain of the same BTV serotype. Lower doses of P2 still provided a significant level of protection even though no neutralizing antibodies could be detected.
已开发出一种大量纯化蓝舌病毒P2中和特异性抗原的方法。纯化后的蛋白质不含病毒特异性或细胞污染物，且保留了其免疫特异性。该纯化方法基于这样的观察结果：通过用单价或二价盐处理，蛋白质P2可从病毒粒子中解离出来。溶解外膜蛋白所需的盐浓度取决于pH值，一般随pH值降低而降低。从聚丙烯酰胺凝胶中提取纯化的P2不会诱导免疫沉淀或中和抗体。另一方面，针对P5的反应对构象的依赖性要小得多，从凝胶中纯化的P5很容易在兔体内诱导出P5沉淀抗体。这些抗体不能中和病毒。用抗核心血清免疫吸附以去除痕量P7的纯化P2被注射到绵羊体内。50微克的初始剂量P2足以诱导出P2沉淀抗体以及中和抗体和血凝抑制抗体。这些绵羊对同一蓝舌病毒血清型的强毒株攻击具有完全的抵抗力。即使检测不到中和抗体，较低剂量的P2仍能提供显著水平的保护。
