Antigenic topology of chlamydial PorB protein and identification of targets for immune neutralization of infectivity
Antigenic topology of chlamydial PorB protein and identification of targets for immune neutralization of infectivity
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DOI：
10.4049/jimmunol.168.10.5184
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发表时间：
2002-05-15
影响因子：
4.4
通讯作者：
Stephens, RS
中科院分区：
文献类型：
--
作者：
Kawa, DE;Stephens, RS
外膜蛋白PorB是一种保守的衣原体蛋白，其功能为孔蛋白，并且能够引发中和抗体。一个拓扑抗原图开发使用重叠的合成肽代表沙眼衣原体PorB序列和多克隆免疫血清。为了确定哪些抗原决定簇是表面可及的，针对PorB肽产生单特异性抗血清，并将其用于斑点印迹和基于ELISA的吸收研究，其中使用了活的Warn dial基本体（EB）。使用标准化体外中和试验研究了表面可及抗原决定簇直接中和Ab应答的能力。鉴定了四个主要抗原簇，分别对应于Phe（3 - 4）-Leu（59）（B1-2和B1-3）、Asp（112）-Glu（145）（B2-3和B2-4）、Gly（179）-Ala（225）（B3-2至B3-4）和瓦尔（261）-Asn（305）（B4-4至B5-2）。总的来说，EB吸附和斑点印迹试验确定免疫反应性PorB抗原暴露在衣原体EB表面。肽特异性抗血清产生的表面可及抗原中和衣原体感染性，并表现出交叉反应性的合成肽代表类似的C。pneumoniae PorB序列。此外，C.沙眼衣原体PorB抗血清被代表表面暴露的PorB抗原决定簇的合成肽抑制。这些结果表明，PorB抗原可能是有用的衣原体疫苗的开发。
The outer membrane protein PorB is a conserved chlamydial protein that functions as a porin and is capable of eliciting neutralizing Abs. A topological antigenic map was developed using overlapping synthetic peptides representing the Chlamydia trachomatis PorB sequence and polyclonal immune sera. To identify which antigenic determinants were surface accessible, monospecific antisera were raised to the PorB peptides and were used in dot-blot and ELISA-based absorption studies with viable Warn dial elementary bodies (EBs). The ability of the surface-accessible antigenic determinants to direct neutralizing Ab responses was investigated using standardized in vitro neutralization assays. Four major antigenic clusters corresponding to Phe(34)-Leu(59) (B1-2 and B1-3), Asp(112)-Glu(145) (B2-3 and B2-4), Gly(179)-Ala(225) (B3-2 to B3-4), and Val(261)-Asn(305) (B4-4 to B5-2) were identified. Collectively, the EB absorption and dot-blot assays established that the immunoreactive PorB Ags were exposed on the surface of chlamydial EBs. Peptide-specific antisera raised to the surface-accessible Ags neutralized chlamydial infectivity and demonstrated cross-reactivity to synthetic peptides representing analogous C. pneumoniae PorB sequences. Furthermore, neutralization of chlamydial infectivity by C. trachomatis PorB antisera was inhibited by synthetic peptides representing the surface-exposed PorB antigenic determinants. These findings demonstrate that PorB Ags may be useful for development of chlamydial vaccines.