Signorino Giacomo, Arnaboldi Paul M, Petzke Mary M, Dattwyler Raymond J
Department of Microbiology, New York Medical College, Valhalla, New York, USA.
Clin Vaccine Immunol. 2014 May;21(5):704-11. doi: 10.1128/CVI.00792-13. Epub 2014 Mar 12.
Laboratory diagnosis of Lyme disease is based on the serological detection of antibodies against the etiologic agent Borrelia burgdorferi. Current diagnostics are insensitive at detecting early infection, when treatment is most effective. This deficiency results from the limited number of B. burgdorferi antigens expressed in early infection and the use of an insensitive two-tier paradigm, put in place to deal with insufficient specificity associated with the use of whole-protein antigens and/or bacterial lysates as serodiagnostic targets. Whole-protein antigens contain epitopes that are unique to B. burgdorferi as well as cross-reactive epitopes found in other bacteria. One method for overcoming the limitations imposed by cross-reactive epitopes is the use of short peptides containing epitopes unique to B. burgdorferi as antigen targets. This eliminates nonspecific epitopes. Using overlapping peptide libraries, we performed epitope mapping of linear epitopes in oligopeptide permease A2 (OppA2), a member of the oligopeptide permease (Opp) family of peptide transporters, expressed during early B. burgdorferi infection. We identified 9 epitopes, synthesized peptides containing these epitopes, and screened those using panels of blood from patients with early Lyme disease, rheumatoid arthritis (RA), or syphilis or from healthy individuals. Two of the peptides, OppA2 (191-225) (amino acids comprising the peptide are shown in parentheses) and OppA2 (381-400), are highly conserved among the three major pathogenic Borrelia species responsible for most Lyme disease cases in North America and Europe. They detected antibodies in Lyme disease patient sera with sufficient sensitivity and specificity to indicate that they could have value in a serological assay for Lyme disease.
莱姆病的实验室诊断基于针对病原体伯氏疏螺旋体的抗体的血清学检测。当前的诊断方法在检测早期感染时不够灵敏，而早期感染时进行治疗最为有效。这种不足源于早期感染中表达的伯氏疏螺旋体抗原数量有限，以及采用了一种不够灵敏的两层检测模式，该模式是为应对使用全蛋白抗原和/或细菌裂解物作为血清学诊断靶点时特异性不足的问题而设立的。全蛋白抗原包含伯氏疏螺旋体特有的表位以及在其他细菌中发现的交叉反应表位。克服交叉反应表位带来的局限性的一种方法是使用含有伯氏疏螺旋体特有的表位的短肽作为抗原靶点。这消除了非特异性表位。我们使用重叠肽库对寡肽通透酶A2（OppA2）中的线性表位进行了表位定位，OppA2是肽转运体寡肽通透酶（Opp）家族的一员，在伯氏疏螺旋体早期感染期间表达。我们鉴定出9个表位，合成了包含这些表位的肽，并使用来自早期莱姆病、类风湿性关节炎（RA）或梅毒患者或健康个体的血液样本进行筛选。其中两个肽，OppA2（191 - 225）（括号内显示构成该肽的氨基酸）和OppA2（381 - 400），在导致北美和欧洲大多数莱姆病病例的三种主要致病性疏螺旋体物种中高度保守。它们在莱姆病患者血清中检测抗体时具有足够的灵敏度和特异性，表明它们在莱姆病的血清学检测中可能具有价值。
