Leptospiral proteins recognized during the humoral immune response to leptospirosis in humans
Leptospiral proteins recognized during the humoral immune response to leptospirosis in humans
复制标题
DOI：
10.1128/iai.69.8.4958-4968.2001
复制
发表时间：
2001-08-01
影响因子：
3.1
通讯作者：
Haake, DA
中科院分区：
文献类型：
--
作者：
Guerreiro, H;Croda, J;Haake, DA
钩端螺旋体病是由钩端螺旋体属致病性螺旋体引起的一种新出现的人畜共患病。了解钩端螺旋体蛋白表达调控是开发新的免疫保护和血清诊断策略的必要条件。我们使用人钩端螺旋体病期间的体液免疫反应作为感染期间表达的蛋白抗原的报告。对来自巴西和巴巴多斯的105例患者的血清进行定性和定量免疫印迹分析。以其他疾病患者和健康个体的血清作为对照。p76、p62、p48、p45、p41、p37和p32等7种蛋白被确定为自然感染期间体液反应的靶点。在疾病的急性期和恢复期，针对脂多糖的抗体主要是免疫球蛋白M (IgM)，而针对蛋白质的抗体则完全是IgG。抗p32反应性具有最大的敏感性和特异性：在急性期和恢复期血清中分别观察到37%和84%的阳性反应，而只有5%的社区对照个体表现出阳性反应。所有致病性钩端螺旋体菌株均表达6种免疫优势抗原；只有p37表达不一致。二维免疫印迹鉴定出7种感染相关抗原中的4种为先前表征的蛋白质：LipL32（主要的外膜脂蛋白），LipL41（表面暴露的外膜脂蛋白）和热休克蛋白GroEL和DnaK。分离研究表明，LipL32和LipL41在外膜部分具有反应性，GroEL和DnaK在细胞质部分具有反应性，而p37似乎是可溶性的质周蛋白。大多数其他免疫优势蛋白，包括p48和p45，都定位于内膜。这些发现表明，在自然感染过程中识别的钩端螺旋体蛋白可能对血清诊断有用，并可能作为疫苗设计的靶点。
Leptospirosis is an emerging zoonosis caused by pathogenic spirochetes belonging to the genus Leptospira. An understanding of leptospiral protein expression regulation is needed to develop new immunoprotective and serodiagnostic strategies. We used the humoral immune response during human leptospirosis as a reporter of protein antigens expressed during infection. Qualitative and quantitative immunoblot analysis was performed using sera from 105 patients from Brazil and Barbados. Sera from patients with other diseases and healthy individuals were evaluated as controls. Seven proteins, p76, p62, p48, p45, p41, p37, and p32, were identified as targets of the humoral response during natural infection. In both acute and convalescent phases of illness, antibodies to lipopolysaccharide were predominantly immunoglobulin M (IgM) while antibodies to proteins were exclusively IgG. Anti-p32 reactivity had the greatest sensitivity and specificity: positive reactions were observed in 37 and 84% of acute- and convalescent-phase sera, respectively, while only 5% of community control individuals demonstrated positive reactions. Six immunodominant antigens were expressed by all pathogenic leptospiral strains tested; only p37 was inconsistently expressed. Two-dimensional immunoblots identified four of the seven infection-associated antigens as being previously characterized proteins: LipL32 (the major outer membrane lipoprotein), LipL41 (a surface-exposed outer membrane lipoprotein), and heat shock proteins GroEL and DnaK. Fractionation studies demonstrated LipL32 and LipL41 reactivity in the outer membrane fraction and GroEL and DnaK in the cytoplasmic fraction, while p37 appeared to be a soluble periplasmic protein. Most of the other immunodominant proteins, including p48 and p45, were localized to the inner membrane. These findings indicate that leptospiral proteins recognized during natural infection are potentially useful for serodiagnosis and may serve as targets for vaccine design.