University of North Carolina-Chapel Hill, Department of Medicine, Division of Infectious Diseases, Chapel Hill, NC, USA.
Sci Rep. 2013;3:1990. doi: 10.1038/srep01990.
Humoral immunity to Plasmodium falciparum circumsporozoite protein is partly mediated by a polymorphic NANP tetra-amino acid repeat. Antibody response to these repeats is the best correlate of protective immunity to the RTS,S malaria vaccine, but few descriptions of the natural variation of these repeats exist. Using capillary electrophoresis to determine the distribution of NANP repeat size polymorphisms among 98 isolates from Lilongwe, Malawi, we characterised the diversity of P. falciparum infection by several ecological indices. Infection by multiple distinct variants was common, and 20 distinct repeat sizes were identified. Diversity of P. falciparum appeared greater in children (18 variants) than adults (12 variants). There was evidence of genetic distance between different geographic regions by Nei's Standard Genetic Distance, suggesting parasite populations vary locally. We show that P. falciparum is very diverse with respect to NANP repeat length even on a local level and that diversity appears higher in children.
对疟原虫环子孢子蛋白的体液免疫部分由一种多态性 NANP 四氨基酸重复序列介导。针对这些重复序列的抗体反应是对 RTS,S 疟疾疫苗的保护性免疫的最佳相关因素，但对这些重复序列的自然变异的描述很少。使用毛细管电泳来确定马拉维利隆圭 98 个分离株中 NANP 重复大小多态性的分布，我们通过几个生态指标来描述疟原虫感染的多样性。多种不同变体的感染很常见，鉴定出了 20 种不同的重复大小。儿童（18 种变体）的疟原虫多样性比成人（12 种变体）更大。不同地理区域之间存在遗传距离的证据表明寄生虫种群在当地发生了变异。我们表明，即使在当地水平，疟原虫在 NANP 重复长度方面也非常多样化，而且儿童中的多样性似乎更高。
