Native Properdin Binds to Chlamydia pneumoniae and Promotes Complement Activation
Native Properdin Binds to Chlamydia pneumoniae and Promotes Complement Activation
复制标题
DOI：
10.1128/iai.00980-10
复制
发表时间：
2011-02-01
影响因子：
3.1
通讯作者：
Pangburn, Michael K.
中科院分区：
文献类型：
--
作者：
Cortes, Claudio;Ferreira, V. P.;Pangburn, Michael K.
补体的激活代表了对来自各种潜在病原体的感染的天然抗性的一种手段。最近，备解素，补体旁路途径的正调节剂，已被证明可以结合到表面并促进补体活化。在这里，我们研究了备解素介导的补体激活是否发生在肺炎衣原体的表面上，肺炎衣原体是一种专性细胞内革兰氏阴性细菌，导致10%至20%的社区获得性肺炎。我们首次确定了人备解素的生理P（2）、P（3）和P（4）形式直接与肺炎衣原体表面结合。这些生理形式的结合加速了肺炎衣原体表面上的补体活化，如通过C3b和C9沉积所测量的。最后，与正常人血清相比，去备解素血清不能控制肺炎衣原体感染HEp-2细胞。然而，加入天然备解素后，备解素耗尽的血清恢复了控制感染的能力。总之，我们的数据表明，备解素是一种模式识别分子，在抵抗衣原体感染中发挥作用。
Activation of complement represents one means of natural resistance to infection from a wide variety of potential pathogens. Recently, properdin, a positive regulator of the alternative pathway of complement, has been shown to bind to surfaces and promote complement activation. Here we studied whether properdin-mediated complement activation occurs on the surface of Chlamydia pneumoniae, an obligate intracellular Gram-negative bacterium that causes 10 to 20% of community-acquired pneumonia. We have determined for the first time that the physiological P(2), P(3), and P(4) forms of human properdin bind to the surface of Chlamydia pneumoniae directly. The binding of these physiological forms accelerates complement activation on the Chlamydia pneumoniae surface, as measured by C3b and C9 deposition. Finally, properdin-depleted serum could not control Chlamydia pneumoniae infection of HEp-2 cells compared with normal human serum. However, after addition of native properdin, the properdin-depleted serum recovered the ability to control the infection. Altogether, our data suggest that properdin is a pattern recognition molecule that plays a role in resistance to Chlamydia infection.