IsdA protects Staphylococcus aureus against the bactericidal protease activity of apolactoferrin
IsdA protects Staphylococcus aureus against the bactericidal protease activity of apolactoferrin
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DOI：
10.1128/iai.01530-07
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发表时间：
2008-04-01
影响因子：
3.1
通讯作者：
Foster, Simon J.
中科院分区：
文献类型：
--
作者：
Clarke, Simon R.;Foster, Simon J.
金黄色葡萄球菌宿主-病原体相互作用的一个重要方面是入侵细菌逃避宿主天然防御的能力，特别是宿主抗菌肽的混合物。在这项工作中，我们发现了金黄色葡萄球菌鼻腔定植所需的一种表面蛋白ISDA与人鼻分泌物中含量最高的抗葡萄球菌多肽乳铁蛋白结合。金黄色葡萄球菌表面ISDA的存在使其对乳铁蛋白的杀伤具有抵抗力。此外，乳铁蛋白的杀菌活性被苯甲基磺酰氟抑制，表明乳铁蛋白的丝氨酸蛋白酶活性在杀灭金黄色葡萄球菌中起作用。重组ISDA是乳铁蛋白水解酶活性的竞争性抑制物。反过来，对ISDA起反应的抗体增强了对金黄色葡萄球菌的杀灭作用。因此，ISDA可以保护金黄色葡萄球菌免受乳铁蛋白的侵害，并作为一种蛋白酶抑制剂。
An important facet of the Staphylococcus aureus host-pathogen interaction is the ability of the invading bacterium to evade host innate defenses, particularly the cocktail of host antimicrobial peptides. In this work, we showed that IsdA, a surface protein of S. aureus which is required for nasal colonization, binds to lactoferrin, the most abundant antistaphylococcal polypeptide in human nasal secretions. The presence of IsdA on the surface of S. aureus confers resistance to killing by lactoferrin. In addition, the bactericidal activity of lactoferrin was inhibited by addition of phenylmethylsulfonyl fluoride, implicating the serine protease activity of lactoferrin in the killing of S. aureus. Recombinant IsdA was a competitive inhibitor of lactoferrin protease activity. Reciprocally, antibody reactive to IsdA enhanced killing of S. aureus. Thus, IsdA can protect S. aureus against lactoferrin and acts as a protease inhibitor.