Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon, South Korea.
Department of Medical Research, Yangon, Myanmar.
Front Cell Infect Microbiol. 2021 Dec 10;11:764293. doi: 10.3389/fcimb.2021.764293. eCollection 2021.
The (Poc) prevalence has increased substantially in sub-Saharan African countries as well as regions of Southeast Asia. Poc parasite biology has not been explored much to date; in particular, the invasion mechanism of this malaria parasite remains unclear. In this study, the binding domain of the Duffy binding protein of (PocDBP) was characterized as an important ligand for reticulocyte invasion. The homologous region of the Duffy binding protein in PocDBP, named PocDBP-RII herein, was selected, and the recombinant PocDBP-RII protein was expressed in an system. This was used to analyze reticulocyte binding activity using fluorescence-activated cell sorting and immune serum production in rabbits. The binding specificity was proven by treating reticulocytes with trypsin, chymotrypsin and neuraminidase. The amino acid sequence homology in the N-terminal Cys-rich region was found to be ~ 44% between PvDBP and PocDBP. The reticulocyte binding activity of PocDBP-RII was significantly higher than the erythrocyte binding activity and was concentration dependent. Erythrocyte binding was reduced significantly by chymotrypsin treatment and inhibited by an anti-PocDBP-RII antibody. This finding suggests that PocDBP may be an important ligand in the reticulocyte invasion process of
（Poc）在撒哈拉以南非洲国家以及东南亚地区的流行率显著增加。迄今为止，Poc 寄生虫生物学尚未得到充分探索；特别是，这种疟原虫的入侵机制仍不清楚。在这项研究中，（PocDBP）的 Duffy 结合蛋白的结合域被表征为红细胞入侵的重要配体。选择 PocDBP 中 Duffy 结合蛋白的同源区域，在此命名为 PocDBP-RII，并在 系统中表达重组 PocDBP-RII 蛋白。这用于使用荧光激活细胞分选和兔免疫血清生产来分析网织红细胞的结合活性。通过用胰蛋白酶、糜蛋白酶和神经氨酸酶处理网织红细胞来证明结合特异性。在 N 端富含半胱氨酸的区域中发现 PvDBP 和 PocDBP 之间的氨基酸序列同源性约为 44%。PocDBP-RII 的网织红细胞结合活性明显高于红细胞结合活性，并且呈浓度依赖性。用胰蛋白酶处理可显著降低红细胞结合，并且抗 PocDBP-RII 抗体可抑制其结合。这一发现表明，PocDBP 可能是红细胞入侵过程中的重要配体。
