Ludolfs Diana, Reinholz Michael, Schmitz Herbert
Department of Virology, Bernhard-Nocht-Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, 20356 Hamburg, Germany.
J Clin Virol. 2009 Jun;45(2):125-8. doi: 10.1016/j.jcv.2009.03.016. Epub 2009 May 5.
In contrast to most antibodies directed to the envelope glycoprotein of flaviviruses, those to the domain III (ED3) show serotype-specific reactions.
Only few epitopes are located on the ED3 [Oliphant T, Engle M, Nybakken GE, Doane C, Johnson S, Huang L, et al. Development of a humanized monoclonal antibody with therapeutic potential against West Nile virus. Nat Med 2005;11:522-30; Nybakken GE, Oliphant T, Johnson S, Burke S, Diamond MS, Fremont DH. Structural basis of West Nile virus neutralization by a therapeutic antibody. Nature 2005;437:764-9; Throsby M, Geuijen C, Goudsmit J, Bakker AQ, Korimbocus J, Kramer RA, et al. Isolation and characterization of human monoclonal antibodies from individuals infected with West Nile virus. J Virol 2006;80:6982-92], and highly sensitive assays may be required to detect the small number of human antibodies to this domain.
We have used a sensitive immune complex (IC) ELISA to detect antibodies to the ED3 of TBE virus [Ludolfs D, Niedrig M, Paweska JT, Schmitz H. Reverse ELISA for the detection of anti-West Nile virus IgG antibodies in humans. Eur J Clin Microbiol Infect Dis 2007;26:467-73; Emmerich P, Gunther S, Schmitz H. Strain-specific antibody response to Lassa virus in the local population of west Africa. J Clin Virol 2008;42:40-4]. This assay was compared with two indirect ELISAs using either the ED3 (ED3 ELISA) or whole tissue culture virus (TCV) (TCV ELISA) as source of antigen. Sera of 45 patients with acute TBE infection and of 65 vaccinees were applied to determine the sensitivity of the IC ELISA.
The IC ELISA detected antibodies in 107 out of 110 samples of TBE patients and vaccinees, 106 of which were also positive with the TCV ELISA. Both tests had a sensitivity of >or=96%. In contrast, the ED3 ELISA had a sensitivity of only 70%. Using samples of 98 West Africans and of 70 Europeans without any contact to TBE virus or TBE virus antigens, the specificity of the IC ELISA was 100% while the specificity of the commercial TCV ELISA varied between 30% with samples of people with acute dengue fever or with yellow fever vaccination and 100% with samples of students from Hamburg without any previous contact to TBE.
Obviously, the IC ELISA is able to detect human antibodies to small antigens with only few serotype-specific epitopes with high specificity and sensitivity.
与大多数针对黄病毒包膜糖蛋白的抗体不同，针对结构域III（ED3）的抗体表现出血清型特异性反应。
ED3上仅存在少数表位[奥利芬特T，恩格尔M，尼巴肯GE，多恩C，约翰逊S，黄L等。一种具有治疗西尼罗河病毒潜力的人源化单克隆抗体的研发。《自然医学》2005年；11：522 - 30；尼巴肯GE，奥利芬特T，约翰逊S，伯克S，戴蒙德MS，弗里蒙特DH。一种治疗性抗体中和西尼罗河病毒的结构基础。《自然》2005年；437：764 - 9；思罗斯比M，格伊延C，古德史密斯J，巴克AQ，科林博克斯J，克莱默RA等。从感染西尼罗河病毒的个体中分离和鉴定人源单克隆抗体。《病毒学杂志》2006年；80：6982 - 92]，可能需要高灵敏度检测方法来检测针对该结构域的少量人抗体。
我们使用了一种灵敏的免疫复合物（IC）ELISA来检测抗蜱传脑炎病毒（TBE病毒）ED3的抗体[卢多夫斯D，尼德里格M，帕韦斯卡JT，施密茨H。用于检测人抗西尼罗河病毒IgG抗体的反向ELISA。《欧洲临床微生物学与传染病杂志》2007年；26：467 - 73；埃默里希P，冈瑟S，施密茨H。西非当地人群对拉沙病毒的毒株特异性抗体反应。《临床病毒学杂志》2008年；4２：40 - 4]。该检测方法与另外两种间接ELISA进行比较，这两种间接ELISA分别使用ED3（ED3 ELISA）或全组织培养病毒（TCV）（TCV ELISA）作为抗原来源。应用4５例急性TBE感染患者和65名疫苗接种者的血清来确定IC ELISA的灵敏度。
IC ELISA在110份TBE患者和疫苗接种者样本中的107份中检测到抗体，其中106份用TCV ELISA检测也呈阳性。两种检测方法的灵敏度均≥96%。相比之下，ED3 ELISA的灵敏度仅为70%。使用98名西非人和70名未接触过TBE病毒或TBE病毒抗原的欧洲人的样本，IC ELISA的特异性为100%，而商业TCV ELISA的特异性在急性登革热患者样本或黄热病疫苗接种者样本中为30%，在之前未接触过TBE的汉堡学生样本中为100%。
显然，IC ELISA能够以高特异性和灵敏度检测针对具有少数血清型特异性表位的小抗原的人抗体。
