Department of Parasitology, Kangwon National University College of Medicine, Chuncheon, Korea.
Trop Med Int Health. 2010 Sep;15(9):1072-6. doi: 10.1111/j.1365-3156.2010.02574.x. Epub 2010 Jun 9.
The Ookinete surface proteins of Plasmodium vivax (P. vivax), Pvs25 and Pvs28, were candidates for the transmission blocking vaccine (TBV), which exhibited great antigenic diversities among various isolates. Polymorphisms of these genes in the isolates from Republic of Korea (ROK) were analysed, which provided valuable baseline data for the field trials of TBV-based vaccines. A total of 98 isolates were collected over 11 years from 1996 to 2007. pvs25 and pvs28 genes from the above isolates were amplified, sequenced and compared against Sal-1 strain. Sequencing analysis of PCR products from P. vivax pvs25 revealed two allelic types, Q97T130 and E97/T130 alleles with the frequencies of 54.5% and 45.5%, respectively, in comparison with Sal I type sequence (E97/I130). From pvs28 gene, polymorphisms at M52L and T140S in the first and third EGF-like domains in comparison to Sal-1 strain were detected, respectively. Six GSGGE tandem repeats followed by GSGGDT or SSGGDT were identified at the end of the fourth EGF-like domain in all Korean isolates. Interestingly, different tandem repeats of amino acid substitutions were observed from isolates collected after 2006 in comparison with preceding years. The ROK isolates revealed limited sequence polymorphisms in pvs25 and tandem repeats in pvs28 in comparison with reported isolates from other nations. Current observations suggested the rapid progresses of genetic changes among Korean isolates.
间日疟原虫（Plasmodium vivax）的动合子表面蛋白（P. vivax），Pvs25 和 Pvs28，是传播阻断疫苗（TBV）的候选物，它们在各种分离株中表现出巨大的抗原多样性。对来自韩国（ROK）的分离株中这些基因的多态性进行了分析，为基于 TBV 的疫苗的现场试验提供了有价值的基线数据。在 1996 年至 2007 年的 11 年间共采集了 98 株分离株。扩增、测序并与 Sal-1 株比较了上述分离株中的 pvs25 和 pvs28 基因。对来自间日疟原虫 pvs25 的 PCR 产物进行测序分析，发现有两种等位基因类型，Q97T130 和 E97/T130 等位基因，其频率分别为 54.5%和 45.5%，与 Sal I 型序列（E97/I130）相比。从 pvs28 基因，在与 Sal-1 株相比的第一和第三个 EGF 样结构域中检测到 M52L 和 T140S 的多态性。在所有韩国分离株的第四个 EGF 样结构域的末端，发现了 6 个 GSGGE 串联重复序列，后面是 GSGGDT 或 SSGGDT。有趣的是，与前几年相比，在 2006 年之后采集的分离株中观察到不同的串联重复氨基酸取代。与来自其他国家的报道分离株相比，ROK 分离株在 pvs25 中的序列多态性有限，在 pvs28 中的串联重复序列有限。目前的观察结果表明，韩国分离株中的遗传变化迅速发展。
