In LipL32, the major leptospiral lipoprotein, the C terminus is the primary immunogenic domain and mediates interaction with collagen wand plasma fibronectin
In LipL32, the major leptospiral lipoprotein, the C terminus is the primary immunogenic domain and mediates interaction with collagen wand plasma fibronectin
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DOI：
10.1128/iai.01639-07
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发表时间：
2008-06-01
影响因子：
3.1
通讯作者：
Ho, Paulo Lee
中科院分区：
文献类型：
--
作者：
Hauk, Pricila;Macedo, Felipe;Ho, Paulo Lee
LipL 32是感染过程中表达的主要钩端螺旋体外膜脂蛋白，是人类对钩端螺旋体病体液免疫应答过程中识别的免疫显性抗原。在这项研究中，我们研究了LipL 32的新方面。为了确定分子的免疫显性结构域，克隆了对应于UpL 32基因的N-末端、中间和C-末端部分的亚片段，并表达蛋白质，并通过金属亲和层析纯化。我们的免疫印迹结果表明，C-末端和中间结构域的LipL 32的实验室确诊的钩端螺旋体病患者的血清所识别。免疫球蛋白M的反应，专门针对LipL 32的C-末端片段在急性和恢复期的疾病。我们还评估了LipL 32与细胞外基质（ECM）组分相互作用的能力。观察到LipL 32与IV型胶原和血浆纤连蛋白的剂量依赖性特异性结合，并且结合能力可归因于该分子的C-末端部分。肝素和明胶都能抑制LipL 32与纤连蛋白的结合，并呈浓度依赖性，表明纤连蛋白的30 kDa肝素结合域和45 kDa明胶结合域参与了这种相互作用。综上所述，我们的结果提供了证据，即LipL 32 C末端在感染过程的早期被识别，并且是负责介导与ECM蛋白相互作用的结构域。
LipL32 is the major leptospiral outer membrane lipoprotein expressed during infection and is the immunodominant antigen recognized during the humoral immune response to leptospirosis in humans. In this study, we investigated novel aspects of LipL32. In order to define the immunodominant domains(s) of the molecule, subfragments corresponding to the N-terminal, intermediate, and C-terminal portions of the UpL32 gene were cloned and the proteins were expressed and purified by metal affinity chromatography. Our immunoblot results indicate that the C-terminal and intermediate domains of LipL32 are recognized by sera of patients with laboratory-confirmed leptospirosis. An immunoglobulin M response was detected exclusively against the LipL32 C-terminal fragment in both the acute and convalescent phases of illness. We also evaluated the capacity of LipL32 to interact with extracellular matrix (ECM) components. Dose-dependent, specific binding of LipL32 to collagen type IV and plasma fibronectin was observed, and the binding capacity could be attributed to the C-terminal portion of this molecule. Both heparin and gelatin could inhibit LipL32 binding to fibronectin in a concentration-dependent manner, indicating that the 30-kDa heparin-binding and 45-kDa gelatin-binding domains of fibronectin are involved in this interaction. Taken together, our results provide evidence that the LipL32 C terminus is recognized early in the course of infection and is the domain responsible for mediating interaction with ECM proteins.