Kyes S, Horrocks P, Newbold C
Molecular Parasitology Group, Weatherall Institute of Molecular Medicine, Headington, Oxford OX3 9DS United Kingdom.
Annu Rev Microbiol. 2001;55:673-707. doi: 10.1146/annurev.micro.55.1.673.
Many pathogens that either rely on an insect vector to complete their life cycle (e.g., Trypanosoma spp. and Borrelia spp.) or exist in a unique ecological niche where transmission from host to host is sporadic (e.g., Neisseria spp.) have evolved strategies to maintain infection of their mammalian hosts for long periods of time in order to ensure their survival. Because they have to survive in the face of a fully functional immune system, a common feature of many of these organisms is their development of sophisticated strategies for immune evasion. For the above organisms and for malaria parasites of the genus Plasmodium, a common theme is the ability to undergo clonal antigenic variation. In all cases, surface molecules that are important targets of the humoral immune response are encoded in the genome as multicopy, nonallelic gene families. Antigenic variation is accomplished by the successive expression of members of these gene families that show little or no immunological cross-reactivity. In the case of malaria parasites, however, some of the molecules that undergo antigenic variation are also major virulence factors, adding an additional level of complication to the host-parasite interaction. In this review, we cover the history of antigenic variation in malaria and then summarize the more recent data with particular emphasis on Plasmodium falciparum, the etiological agent of the most severe form of human malaria.
许多病原体，要么依赖昆虫媒介来完成其生命周期（如锥虫属和疏螺旋体属），要么存在于独特的生态位中，宿主间的传播是零星发生的（如奈瑟菌属），它们已经进化出一些策略，以便长时间维持对其哺乳动物宿主的感染，从而确保自身的生存。由于它们必须在功能完备的免疫系统面前存活下来，这些生物体中的许多都有一个共同特征，即它们会发展出复杂的免疫逃避策略。对于上述生物体以及疟原虫属的疟原虫来说，一个共同的主题是能够进行克隆性抗原变异。在所有情况下，作为体液免疫反应重要靶标的表面分子，在基因组中被编码为多拷贝、非等位基因家族。抗原变异是通过这些基因家族成员的相继表达来实现的，这些成员之间几乎没有或没有免疫交叉反应。然而，就疟原虫而言，一些发生抗原变异的分子也是主要的毒力因子，这给宿主 - 寄生虫相互作用增添了额外的复杂性。在这篇综述中，我们涵盖了疟疾抗原变异的历史，然后总结了最新的数据，特别强调了恶性疟原虫，它是人类最严重形式疟疾的病原体。
