School of Life Sciences, Faculty of Medicine and Health Sciences, The University of Nottingham, Nottingham, UK.
Wolfson Centre for Global Virus Infections, The University of Nottingham, Nottingham, UK.
J Gen Virol. 2022 Mar;103(3). doi: 10.1099/jgv.0.001727.
Hepatitis C virus (HCV) infection affects more than 71 million people worldwide. The disease slowly progresses to chronic, long-term liver injury which leads to hepatocellular carcinoma (HCC) in 5 % of infections. The alternative reading frame protein (ARFP/core+1) is encoded by a sequence overlapping the HCV core gene in the +1 reading frame. Its role in hepatitis C pathogenesis and the viral life cycle is unclear, although some observers have related its production to disease progression and the development of HCC. The aim of this study was to determine whether ARFP is immunogenic in patients with chronic HCV genotype 3 infection and to assess whether sero-reactivity is associated with disease progression, particularly to HCC. Immunogenic epitopes within the protein were predicted by a bioinformatics tool, and three -20 aa length-peptides (ARFP-P1, ARFP-P2 and ARFP-P3) were synthesized and used in an avidin-biotin ARFP/core+1 peptide ELISA. Serum samples from 50 patients with chronic HCV genotype 3 infection, 50 genotype-1 patients, 50 HBV patients and 110 healthy controls were tested. Sero-reactivity to the ARFP peptides was also tested and compared in 114 chronic HCV genotype-3 patients subdivided on the basis of disease severity into non-cirrhotic, cirrhotic and HCC groups. Chronic HCV genotype-3 patients showed noticeable rates of reactivity to ARFP and core peptides. Seropositivity rates were 58% for ARFP-P1, 47 % for ARFP-P2, 5.9 % for ARFP-P3 and 100 % for C22 peptides. There was no significant difference between these seroreactivities between HCV genotype-3 patients with HCC, and HCV genotype-3 patients with and without liver cirrhosis. Patients with chronic HCV genotype-3 infection frequently produce antibodies against ARFP/core+1 protein. ARFP peptide reactivity was not associated with disease severity in patients with HCV genotype-3. These results support the conclusion that ARFP/core+1 is produced during HCV infection, but they do not confirm that antibodies to ARFP can indicate HCV disease progression.
丙型肝炎病毒 (HCV) 感染影响全球超过 7100 万人。该疾病缓慢进展为慢性、长期肝损伤，导致 5%的感染发展为肝细胞癌 (HCC)。替代阅读框蛋白 (ARFP/core+1) 由 HCV 核心基因在 +1 阅读框中重叠的序列编码。其在丙型肝炎发病机制和病毒生命周期中的作用尚不清楚，尽管一些观察人员将其产生与疾病进展和 HCC 的发展联系起来。本研究旨在确定 ARFP 是否在慢性丙型肝炎基因型 3 感染患者中具有免疫原性，并评估血清反应性是否与疾病进展相关，特别是与 HCC 相关。通过生物信息学工具预测该蛋白中的免疫原性表位，并合成了三个 20 个氨基酸长度的肽 (ARFP-P1、ARFP-P2 和 ARFP-P3)，并用于亲和素-生物素 ARFP/core+1 肽 ELISA。检测了 50 名慢性丙型肝炎基因型 3 感染患者、50 名基因型 1 患者、50 名乙型肝炎患者和 110 名健康对照者的血清样本。还在基于疾病严重程度分为非肝硬化、肝硬化和 HCC 组的 114 名慢性丙型肝炎基因型 3 患者中测试了对 ARFP 肽的血清反应性，并进行了比较。慢性丙型肝炎基因型 3 患者对 ARFP 和核心肽表现出明显的反应性。ARFP-P1 的血清阳性率为 58%，ARFP-P2 为 47%，ARFP-P3 为 5.9%，C22 肽为 100%。丙型肝炎基因型 3 患者中 HCC 患者与丙型肝炎基因型 3 患者伴或不伴肝硬化患者之间，这些血清反应性无显著差异。慢性丙型肝炎基因型 3 感染患者常产生针对 ARFP/core+1 蛋白的抗体。ARFP 肽反应性与丙型肝炎基因型 3 患者的疾病严重程度无关。这些结果支持 ARFP/core+1 在 HCV 感染期间产生的结论，但它们不能证实针对 ARFP 的抗体可指示 HCV 疾病进展。
