Tabll Ashraf A, Salem Eman A, El-Abd Yasmine S, El-Shenawy Reem M, Saad Amr, Abdallah Sanaa O, Dawood Reham M, El-Awady Mostafa K
Clin Lab. 2016 Oct 1;62(10):1879-1885. doi: 10.7754/Clin.Lab.2016.160108.
Hepatitis C virus (HCV) is a major health problem worldwide particularly in Egypt. The humoral immune response has an important function in the control of HCV infection. The aim of this study was to investigate the role of neutralizing antibodies in Hepatitis C Virus (HCV) clearance in infected individuals.
This study was carried out on apparently healthy blood donors (n = 200). Detectable HCV antibodies were assessed by commercial ELISA and specific human immunoglobulins targeting peptides derived from HCV E1/E2 glycoproteins were measured in donors' blood using an in house optimized ELISA. Human IgG purification was carried out from positive HCV RNA and negative HCV RNA samples in order to evaluate its neutralizing activity in vitro using Huh 7 cells.
The studied cohort included 96/200 subjects who tested positive for HCV antibodies, among which 56/96 (58%) samples were positive for HCV RNA (Group 1) and 40/96 (42%) samples had undetectable HCV RNA (Group 2). ELISA results showed that Human HCV immunoglobulin (HHI) targeting HCV E1 synthetic peptide (a.a. 315 - 323) was detectable in 63/96 (66%) and HHI targeting HCV E2 (a.a. 412 - 419) tested positive in 14/96 (15%) while 19/96 (20%) were positive for HCV E2 (a.a. 517 - 531). HHI higher than the cutoff level against peptide HCV E1 (a.a. 315 - 323) was detected in 22/63 (35%) in Group 2 and positive in 41/63 (65%) in Group 1. HHI against peptide HCV E2 (a.a. 412 - 419) was positive in 7 (50%) blood donors in Group 2 and also positive in 7 (50%) of Group 1. While HHI targeting HCV E2 (a.a. 517 - 531) was positive in 11 (60%) in Group 2 compared with 8 cases (40%) in Group 1. Purified human antibodies from cases positive for HCV antibodies and negative for HCV RNA showed in vitro neutralization at concentrations 30 and 10 µg/mL while the same concentration of purified human IgG from cases positive for HCV RNA showed no viral neutralization.
The tested epitope(s) derived from HCV envelope E1 and E2 are important for viral clearance and hence can be used for HCV vaccine development.
丙型肝炎病毒（HCV）是全球尤其是埃及面临的一个主要健康问题。体液免疫反应在控制HCV感染中具有重要作用。本研究的目的是调查中和抗体在感染个体清除丙型肝炎病毒（HCV）中的作用。
本研究对表面健康的献血者（n = 200）进行。通过商业酶联免疫吸附测定（ELISA）评估可检测到的HCV抗体，并使用内部优化的ELISA在献血者血液中测量靶向源自HCV E1/E2糖蛋白的肽的特异性人免疫球蛋白。从HCV RNA阳性和HCV RNA阴性样本中进行人IgG纯化，以便使用Huh 7细胞在体外评估其中和活性。
研究队列包括96/200名HCV抗体检测呈阳性的受试者，其中56/96（58%）样本HCV RNA呈阳性（第1组），40/96（42%）样本未检测到HCV RNA（第2组）。ELISA结果显示，靶向HCV E1合成肽（氨基酸315 - 323）的人HCV免疫球蛋白（HHI）在63/96（66%）中可检测到，靶向HCV E2（氨基酸412 - 419）的HHI在14/96（15%）中检测呈阳性，而19/96（20%）对HCV E2（氨基酸517 - 531）呈阳性。第2组中22/63（35%）检测到针对肽HCV E1（氨基酸315 - 323）高于临界水平的HHI，第1组中41/63（65%）呈阳性。针对肽HCV E2（氨基酸412 - 419）的HHI在第2组7名（50%）献血者中呈阳性，第1组7名（50%）中也呈阳性。而靶向HCV E2（氨基酸517 - 531）的HHI在第2组11名（60%）中呈阳性，第1组为8例（40%）。从HCV抗体阳性且HCV RNA阴性的病例中纯化的人抗体在浓度为30和10μg/mL时显示出体外中和作用，而来自HCV RNA阳性病例的相同浓度的纯化人IgG未显示病毒中和作用。
源自HCV包膜E1和E2的测试表位对病毒清除很重要，因此可用于HCV疫苗开发。
