Anaplasma phagocytophilum Hijacks Flotillin and NPC1 Complex To Acquire Intracellular Cholesterol for Proliferation, Which Can Be Inhibited with Ezetimibe.
Anaplasma phagocytophilum Hijacks Flotillin and NPC1 Complex To Acquire Intracellular Cholesterol for Proliferation, Which Can Be Inhibited with Ezetimibe.
复制标题
Anaplasma吞噬细胞杀虫剂劫持植虫和NPC1复合物以获取细胞内胆固醇以进行增生，可以用ezetimibe抑制。
DOI：
10.1128/mbio.02299-21
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发表时间：
2021-10-26
期刊：
影响因子：
6.4
通讯作者：
Rikihisa Y
中科院分区：
文献类型：
--
作者：
Huang W;Xiong Q;Lin M;Rikihisa Y
细胞内胆固醇转运蛋白Niemann-Pick C1型(NPC1)和脂筏蛋白FLOT(FLOT)是细胞内必需的细菌吞噬无浆菌摄取胆固醇和感染所必需的，每种蛋白都定位于含有复制细菌的膜结合包涵体。在这里，我们发现FLOT2在NPC1排列的囊泡中有显著的定位，并且FLOT2和NPC1之间存在物理相互作用。这种相互作用是胆固醇依赖的，因为FLOT2的CRAC(胆固醇识别/相互作用氨基酸-胆固醇结合)结构域突变不与NPC1相互作用，而胆固醇隔离剂甲基-β-环糊精减少了这种相互作用。FLOT2，FLOT21-183，其口腔抑制素-fltillin-hflc/K结构域足以进行独特的FLOT2定位和与NPC1的相互作用。NPC1、FLOT2和FLOT21-183流向无浆包涵体的管腔。功能缺失的突变体NPC1P691S(类固醇敏感结构域的突变)不与FLOT2或无浆体包涵体共定位或相互作用，并抑制感染。依折麦布是一种通过抑制质膜Niemann-Pick C1-like 1与FLOT的相互作用来阻止胆固醇在小肠中的吸收的药物。Ezetimibe阻断NPC1和FLOT2之间的相互作用，抑制无浆体感染。依折麦布不能直接抑制无浆体的增殖，但能抑制宿主膜脂和胆固醇向包涵体内细菌的运输。这些数据表明，无浆体劫持了与FLOT2结合的含有胆固醇的NPC1囊泡，将胆固醇输送到无浆体包涵体中，以同化胆固醇促进其增殖。这些结果提供了对细胞内胆固醇运输机制的洞察，并提供了一种潜在的方法，通过阻止胆固醇输送到细菌包涵体的管腔来抑制无浆体感染。
The intracellular cholesterol transport protein Niemann-Pick type C1 (NPC1) and lipid-raft protein flotillin (FLOT) are required for cholesterol uptake by the obligatory intracellular bacterium Anaplasma phagocytophilum and for infection, and each protein localizes to membrane-bound inclusions containing replicating bacteria. Here, we found striking localization of FLOT2 in NPC1-lined vesicles and a physical interaction between FLOT2 and NPC1. This interaction was cholesterol dependent, as a CRAC (cholesterol recognition/interaction amino acid cholesterol-binding) domain mutant of FLOT2 did not interact with NPC1, and the cholesterol-sequestering agent methyl-β-cyclodextrin reduced the interaction. The stomatin-prohibitin-flotillin-HflC/K domain of FLOT2, FLOT21–183, was sufficient for the unique FLOT2 localization and interaction with NPC1. NPC1, FLOT2, and FLOT21–183 trafficked to the lumen of Anaplasma inclusions. A loss-of-function mutant, NPC1P691S (mutation in the sterol-sensing domain), did not colocalize or interact with FLOT2 or with Anaplasma inclusions and inhibited infection. Ezetimibe is a drug that blocks cholesterol absorption in the small intestine by inhibiting plasma membrane Niemann-Pick C1-like 1 interaction with FLOTs. Ezetimibe blocked the interaction between NPC1 and FLOT2 and inhibited Anaplasma infection. Ezetimibe did not directly inhibit Anaplasma proliferation but inhibited host membrane lipid and cholesterol traffic to the bacteria in the inclusion. These data suggest that Anaplasma hijacks NPC1 vesicles containing cholesterol bound to FLOT2 to deliver cholesterol into Anaplasma inclusions to assimilate cholesterol for its proliferation. These results provide insights into mechanisms of intracellular cholesterol transport and a potential approach to inhibit Anaplasma infection by blocking cholesterol delivery into the lumen of bacterial inclusions.