Bülow R, Boothroyd J C
Department of Microbiology and Immunology, Stanford University School of Medicine, CA 94305-5402.
J Immunol. 1991 Nov 15;147(10):3496-500.
Using liposomes as adjuvant, a purified membrane Ag from Toxoplasma gondii (p30) has been tested for its protective effect in mice. Immunization with p30 in liposomes resulted in only one in 15 mice dying from a challenge that killed 11 of 15 control mice (receiving only buffer or liposomes without p30). The p30 Ag alone gave intermediate levels of protection, with 5 of 15 animals dying. The source of the p30 Ag was the rapidly growing, laboratory-adapted strain of T. gondii, RH; challenge was with the recently isolated C strain which still has all the properties of a wild-type strain. To assess the validity of this combination, the amino acid sequence of p30 from these two strains (as predicted from the corresponding gene sequence) was compared and found to differ in only eight residues. This minimal variation argued that RH was a valid source of material for a subunit vaccine, as subsequently confirmed by the protection studies. These results indicate that p30 is an appropriate Ag for development into a subunit vaccine for immunization of humans and/or domestic livestock, which are a major source of human infection.
以脂质体作为佐剂，对一种来自刚地弓形虫的纯化膜抗原（p30）在小鼠体内的保护作用进行了测试。用脂质体包裹的p30免疫小鼠后，15只小鼠中只有1只在攻毒后死亡，而15只对照小鼠（仅接受缓冲液或不含p30的脂质体）中有11只在攻毒后死亡。单独使用p30抗原时，保护水平处于中等，15只动物中有5只死亡。p30抗原的来源是实验室适应的快速生长的刚地弓形虫RH株；攻毒使用的是最近分离的C株，该株仍具有野生型菌株的所有特性。为评估这种组合的有效性，对这两个菌株的p30氨基酸序列（根据相应基因序列预测）进行了比较，发现仅在8个残基上存在差异。这种微小的差异表明RH是亚单位疫苗的有效材料来源，后续的保护研究证实了这一点。这些结果表明，p30是开发用于人类和/或家畜免疫的亚单位疫苗的合适抗原，而人类和家畜是人类感染的主要来源。
