Verra F, Hughes A L
Department of Biology, Pennsylvania State University, University Park 16801-5301, USA.
Parassitologia. 1999 Sep;41(1-3):93-5.
The Apical Membrane Antigen-1 (AMA-1) is a protein localized in the apical organelles of the merozoite, one of the stages in the life cycle of malaria parasites (Plasmodium spp.) that infects the vertebrate host. This antigen, which is encoded by a single polymorphic locus, plays a role in evading immune detection and mediating invasion into target host cells. We found evidence of positive Darwinian selection on immunogenic regions of P. falciparum AMA-1 favoring genetic diversity in the T-cell epitopes and in regions likely to interact with host antibodies. These results support the hypothesis that polymorphism at the AMA-1 locus in maintained by balancing selection arising from host immune recognition.
顶端膜抗原1（AMA-1）是一种定位于裂殖子顶端细胞器的蛋白质，裂殖子是疟原虫（疟原虫属）生命周期中的一个阶段，可感染脊椎动物宿主。该抗原由单个多态性位点编码，在逃避免疫检测和介导侵入靶宿主细胞中发挥作用。我们发现恶性疟原虫AMA-1免疫原性区域存在正达尔文选择的证据，这有利于T细胞表位以及可能与宿主抗体相互作用区域的遗传多样性。这些结果支持了这样的假说，即AMA-1位点的多态性是由宿主免疫识别产生的平衡选择所维持的。
