Shoberg R J, Jonsson M, Sadziene A, Bergström S, Thomas D D
Department of Periodontics, University of Texas Health Science Center at San Antonio 78284.
J Clin Microbiol. 1994 Feb;32(2):489-500. doi: 10.1128/jcm.32.2.489-500.1994.
The outer surface lipoprotein B (OspB) of Borrelia burgdorferi is a major component of the borrelial protein profile and has been shown to be highly immunogenic in experimentally immunized and infected mammals. However, the ospB loci of different strains show considerable heterology at the nucleic acid sequence level, and the progeny of a clonal strain of B. burgdorferi exhibited OspB polymorphisms with respect to apparent molecular weights and reactivities with monoclonal antibodies. These data suggest that OspB is not a good candidate for vaccination or diagnostic purposes. The present study describes a monoclonal antibody, designated 84C, directed against a very highly conserved domain of the OspB lipoprotein. Western immunoblot analysis with 84C demonstrated reactivity in 84.2% of human, tick, and other vertebrate isolate strains examined from widely diverse geographic regions, including strains of B. burgdorferi sensu stricto and two closely related species, B. garinii and B. afzelii. The 84C-binding region was delimited to a highly conserved 11-amino-acid region in the carboxyl terminus of OspB as demonstrated by (i) DNA sequence analysis of wild-type and 84C-resistant mutant ospB alleles and (ii) deletion mutagenesis of a recombinant ospB gene in Escherichia coli. Finally, the 84C epitope was demonstrated to be exposed on the borrelial surface in situ as (i) the monoclonal antibody 84C was able to agglutinate borrelias in culture and (ii) 84C-resistant escape variants were isolated. These data suggest that the potential value of OspB as a vaccine candidate or diagnostic tool be examined more closely, in the context of the 84C-reactive domain.
伯氏疏螺旋体的外表面脂蛋白B（OspB）是疏螺旋体蛋白质谱的主要成分，在实验免疫和感染的哺乳动物中已显示出高度免疫原性。然而，不同菌株的ospB基因座在核酸序列水平上表现出相当大的异源性，并且伯氏疏螺旋体克隆菌株的后代在表观分子量和与单克隆抗体的反应性方面表现出OspB多态性。这些数据表明，OspB不是疫苗接种或诊断用途的良好候选者。本研究描述了一种针对OspB脂蛋白非常高度保守结构域的单克隆抗体，命名为84C。用84C进行的Western免疫印迹分析表明，在从广泛不同地理区域分离的84.2%的人、蜱和其他脊椎动物菌株中具有反应性，包括狭义伯氏疏螺旋体菌株以及两个密切相关的物种，即伽氏疏螺旋体和阿氏疏螺旋体。如通过（i）野生型和84C抗性突变体ospB等位基因的DNA序列分析以及（ii）大肠杆菌中重组ospB基因的缺失诱变所证明的，84C结合区域被限定在OspB羧基末端高度保守的11个氨基酸区域。最后，84C表位被证明在原位暴露于疏螺旋体表面，因为（i）单克隆抗体84C能够凝集培养物中的疏螺旋体，并且（ii）分离出了84C抗性逃逸变体。这些数据表明，在84C反应性结构域的背景下，应更仔细地研究OspB作为疫苗候选物或诊断工具的潜在价值。
