College of Animal Science and Technology, Shihezi University, Shihezi, China.
Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China.
Front Cell Infect Microbiol. 2024 Apr 30;14:1341332. doi: 10.3389/fcimb.2024.1341332. eCollection 2024.
The Crimean-Congo hemorrhagic fever virus (CCHFV), the most geographically widespread tick-borne virus, is endemic in Africa, Eastern Europe and Asia, with infection resulting in mortality in up to 30% of cases. Currently, there are no approved vaccines or effective therapies available for CCHF. The CCHFV should only be manipulated in the BSL-4 laboratory, which has severely hampered basic seroprevalence studies.
In the present study, two antibody detection methods in the forms of an enzyme-linked immunosorbent assay (ELISA) and a surrogate virus neutralization test (sPVNT) were developed using a recombinant glycoprotein (rGP) and a vesicular stomatitis virus (VSV)-based virus bearing the CCHFV recombinant glycoprotein (rVSV/CCHFV) in a biosafety level 2 (BSL-2) laboratory, respectively.
The rGP-based ELISA and rVSV/CCHFV-based sVNT were established by using the anti-CCHFV pre-G mAb 11E7, known as a broadly cross-reactive, potently neutralizing antibody, and their applications as diagnostic antigens were validated for the specific detection of CCHFV IgG and neutralizing antibodies in experimental animals. In two tests, mAb clone 11E7 (diluted at 1:163840 or 512) still displayed positive binding and neutralization, and the presence of antibodies (IgG and neutralizing) against the rGP and rVSV/CCHFV was also determined in the sera from the experimental animals. Both mAb 11E7 and animal sera showed a high reactivity to both antigens, indicating that bacterially expressed rGP and rVSV/CCHFV have good immunoreactivity. Apart from establishing two serological testing methods, their results also demonstrated an imperfect correlation between IgG and neutralizing antibodies.
Within this limited number of samples, the rGP and rVSV/CCHFV could be safe and convenient tools with significant potential for research on specific antibodies and serological samples.
克里米亚-刚果出血热病毒（CCHFV）是分布最广的蜱传病毒，在非洲、东欧和亚洲流行，感染后的死亡率高达 30%。目前，尚无针对 CCHF 的批准疫苗或有效疗法。CCHFV 只能在生物安全 4 级（BSL-4）实验室中操作，这严重阻碍了基本血清流行率研究。
在本研究中，使用重组糖蛋白（rGP）和携带 CCHFV 重组糖蛋白的水疱性口炎病毒（VSV）（rVSV/CCHFV）在生物安全 2 级（BSL-2）实验室中分别开发了酶联免疫吸附测定（ELISA）和替代病毒中和试验（sPVNT）两种抗体检测方法。
rGP 基于 ELISA 和 rVSV/CCHFV 基于 sVNT 的建立是使用抗 CCHFV 前 G mAb 11E7 进行的，11E7 是一种广泛交叉反应、具有强大中和能力的抗体，其作为诊断抗原的应用在实验动物中验证了对 CCHFV IgG 和中和抗体的特异性检测。在两项测试中，mAb 克隆 11E7（稀释度为 1:163840 或 512）仍显示出阳性结合和中和，并且在实验动物的血清中也确定了针对 rGP 和 rVSV/CCHFV 的抗体（IgG 和中和）的存在。mAb 11E7 和动物血清均对两种抗原表现出高反应性，表明细菌表达的 rGP 和 rVSV/CCHFV 具有良好的免疫原性。除了建立两种血清学检测方法外，它们的结果还表明 IgG 和中和抗体之间存在不完全相关。
在这个有限的样本数量中，rGP 和 rVSV/CCHFV 可以是安全方便的工具，具有研究特异性抗体和血清样本的巨大潜力。
