Plasmodium falciparum Calcium-Dependent Protein Kinase 2 Is Critical for Male Gametocyte Exflagellation but Not Essential for Asexual Proliferation
Plasmodium falciparum Calcium-Dependent Protein Kinase 2 Is Critical for Male Gametocyte Exflagellation but Not Essential for Asexual Proliferation
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DOI：
10.1128/mbio.01656-17
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发表时间：
2017-09-01
期刊：
影响因子：
6.4
通讯作者：
Miller, Louis H.
中科院分区：
文献类型：
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作者：
Bansal, Abhisheka;Molina-Cruz, Alvaro;Miller, Louis H.
药物开发工作主要集中在疟疾寄生虫恶性疟原虫的无性血液阶段。除了伯氨喹，它有自己的局限性，没有可用的药物，针对寄生虫传播到蚊子。因此，需要验证可以靶向阻断传播的新寄生虫蛋白。恶性疟原虫钙依赖性蛋白激酶（PfCDPKs）在寄生虫生命周期的各个阶段发挥关键作用，重要的是，在人类宿主中不存在。这些特征使它们成为有吸引力的药物靶点。在这项研究中，使用CRISPR/Cas9，我们成功地从血液阶段的寄生虫中敲除了PfCDPK 2，这在以前被认为是一种不可或缺的蛋白质。PfCDPK 2敲除（KO）寄生虫的生长速率与野生型寄生虫的生长速率相似，证实PfCDPK 2功能对于体外寄生虫的无性增殖不是必需的。PfCDPK 2 KO寄生虫的成熟雄配子体和雌配子体在诱导后变圆。然而，由于雄配子体出丝和雌配子体可能存在缺陷，它们不能感染雌性斯氏按蚊。重要性尽管疟疾导致的死亡人数减少，但它仍然是发展中国家的主要传染病。为了有效控制和消除疟疾，需要针对寄生虫的多个阶段。其中一个阶段包括将寄生虫传播给蚊子。在这里，我们证明了PfCDPK 2的成功敲除，这是以前被认为是必不可少的寄生虫在红细胞中的生长。PfCDPK 2 KO寄生虫不能在蚊子中建立感染。因此，我们的研究表明，靶向PfCDPK 2可能是在高传播国家控制疟疾传播的良好策略。此外，PfCDPK 2信号通路的分子理解可能为疟疾控制提供额外的目标。
Drug development efforts have focused mostly on the asexual blood stages of the malaria parasite Plasmodium falciparum. Except for primaquine, which has its own limitations, there are no available drugs that target the transmission of the parasite to mosquitoes. Therefore, there is a need to validate new parasite proteins that can be targeted for blocking transmission. P. falciparum calcium-dependent protein kinases (PfCDPKs) play critical roles at various stages of the parasite life cycle and, importantly, are absent in the human host. These features mark them as attractive drug targets. In this study, using CRISPR/Cas9 we successfully knocked out PfCDPK2 from blood-stage parasites, which was previously thought to be an indispensable protein. The growth rate of the PfCDPK2 knockout (KO) parasites was similar to that of wild-type parasites, confirming that PfCDPK2 function is not essential for the asexual proliferation of the parasite in vitro. The mature male and female gametocytes of PfCDPK2 KO parasites become round after induction. However, they fail to infect female Anopheles stephensi mosquitoes due to a defect(s) in male gametocyte exflagellation and possibly in female gametes.IMPORTANCE Despite reductions in the number of deaths it causes, malaria continues to be a leading infectious disease of the developing world. For effective control and elimination of malaria, multiple stages of the parasite need to be targeted. One such stage includes the transmission of the parasite to mosquitoes. Here, we demonstrate the successful knockout of PfCDPK2, which was previously thought to be indispensable for parasite growth in red blood cells. The PfCDPK2 KO parasites are incapable of establishing an infection in mosquitoes. Therefore, our study suggests that targeting PfCDPK2 may be a good strategy to control malaria transmission in countries with high transmission. Moreover, molecular understanding of the signaling pathway of PfCDPK2 may provide additional targets for malaria control.