Splenic Retention of Plasmodium falciparum Gametocytes To Block the Transmission of Malaria
Splenic Retention of Plasmodium falciparum Gametocytes To Block the Transmission of Malaria
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DOI：
10.1128/aac.05030-14
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发表时间：
2015-07-01
影响因子：
4.9
通讯作者：
Buffet, Pierre A.
中科院分区：
文献类型：
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作者：
Duez, Julien;Holleran, John P.;Buffet, Pierre A.
恶性疟原虫通过被称为配子细胞的性红细胞形式从人类传播给按蚊载体。红细胞滤过微球层（微滤过）显示循环配子体是可变形的。降低配子体变形能力的化合物会诱导其脾清除，从而将其从血液循环中清除，阻断疟疾传播。手工制作的单样品微滴原型被缩小为96孔微滴板格式，配子体在微球过滤器中的保留量通过高含量成像进行量化。在微滴板上评估了40种药理化合物的硬化活性，使用小分子（花青素）作为阳性对照。在模拟脾脏微流控芯片和巨噬细胞缺失小鼠中评估了calyculin的硬化活性。在微孔板中，暴露于对寄生虫生存能力没有影响的浓度的花绿素后，成熟配子体获得了明显的机械保留（80%至90%）。在测试的40种化合物中，包括20种抗疟药，只有5种内过氧化物显著增加配子体保留（1.5- 2.5倍；在1 μ M下暴露24小时）。成熟配子体暴露于微流控芯片中的calcyculin积累，并与热硬化红细胞一样迅速地从巨噬细胞缺失小鼠的循环中清除，从而证实了用微滤法获得的结果。建立了一种自动化的小型化方法来选择具有配子细胞硬化效应的化合物。硬化诱导配子体在体内和体外清除。基于经生理学验证的工具，这种筛选级联可以识别新的化合物并发现阻断疟疾传播的新靶点。在血液学的创新应用也设想。
Plasmodium falciparum is transmitted from humans to Anopheles mosquito vectors via the sexual erythrocytic forms termed gametocytes. Erythrocyte filtration through microsphere layers (microsphiltration) had shown that circulating gametocytes are deformable. Compounds reducing gametocyte deformability would induce their splenic clearance, thus removing them from the blood circulation and blocking malaria transmission. The hand-made, single-sample prototype for microsphiltration was miniaturized to a 96-well microtiter plate format, and gametocyte retention in the microsphere filters was quantified by high-content imaging. The stiffening activity of 40 pharmacological compounds was assessed in microtiter plates, using a small molecule (calyculin) as a positive control. The stiffening activity of calyculin was assessed in spleen-mimetic microfluidic chips and in macrophage-depleted mice. Marked mechanical retention (80% to 90%) of mature gametocytes was obtained in microplates following exposure to calyculin at concentrations with no effect on parasite viability. Of the 40 compounds tested, including 20 antimalarials, only 5 endoperoxides significantly increased gametocyte retention (1.5- to 2.5-fold; 24 h of exposure at 1 mu M). Mature gametocytes exposed to calyculin accumulated in microfluidic chips and were cleared from the circulation of macrophagedepleted mice as rapidly as heat-stiffened erythrocytes, thus confirming results obtained using the microsphiltration assay. An automated miniaturized approach to select compounds for their gametocyte-stiffening effect has been established. Stiffening induces gametocyte clearance both in vitro and in vivo. Based on physiologically validated tools, this screening cascade can identify novel compounds and uncover new targets to block malaria transmission. Innovative applications in hematology are also envisioned.