The parasite preferentially invades human reticulocytes. Its merozoite surface protein 1 paralog (PvMSP1P), particularly the 19-kDa C-terminal region (PvMSP1P-19), has been shown to bind to reticulocytes, and this binding can be inhibited by antisera obtained by PvMSP1P-19 immunization. The molecular mechanism of interactions between PvMSP1P-19 and reticulocytes during invasion, however, remains unclear. In this study, we analyzed the ability of MSP1P-19 to bind to different concentrations of reticulocytes and confirmed its reticulocyte preference. LC-MS analysis was used to identify two potential reticulocyte receptors, band3 and CD71, that interact with MSP1P-19. Both PvMSP1P-19 and its sister taxon MSP1P-19 were found to bind to the extracellular loop (loop 5) of band3, where the interaction of MSP1P-19 with band3 was chymotrypsin sensitive. Antibodies against band3-P5, CD71, and MSP1P-19 reduced the binding activity of PvMSP1P-19 and MSP1P-19 to reticulocytes, while MSP1P-19 proteins inhibited invasion in a concentration-dependent manner. To sum up, identification and characterization of the reticulocyte receptor is important for understanding the binding of reticulocytes by MSP1P-19.

中文翻译：

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间日疟原虫 MSP1P-19 通过与膜蛋白 band3 和 CD71 相互作用参与网织红细胞的结合


该寄生虫优先侵入人类网织红细胞。其裂殖子表面蛋白 1 旁系同源物 (PvMSP1P)，特别是 19-kDa C 末端区域 (PvMSP1P-19)，已被证明可与网织红细胞结合，并且这种结合可被 PvMSP1P-19 免疫获得的抗血清抑制。然而，PvMSP1P-19 与网织红细胞在侵袭过程中相互作用的分子机制仍不清楚。在本研究中，我们分析了MSP1P-19与不同浓度网织红细胞结合的能力，并证实了其网织红​​细胞偏好。 LC-MS 分析用于鉴定与 MSP1P-19 相互作用的两种潜在网织红细胞受体 band3 和 CD71。发现 PvMSP1P-19 及其姐妹分类单元 MSP1P-19 均与 band3 的细胞外环（环 5）结合，其中 MSP1P-19 与 band3 的相互作用对胰凝乳蛋白酶敏感。 band3-P5、CD71 和 MSP1P-19 抗体降低了 PvMSP1P-19 和 MSP1P-19 与网织红细胞的结合活性，而 MSP1P-19 蛋白以浓度依赖性方式抑制侵袭。综上所述，网织红细胞受体的鉴定和表征对于理解 MSP1P-19 与网织红细胞的结合具有重要意义。