Czarnota Anna, Offersgaard Anna, Pihl Anne Finne, Prentoe Jannick, Bukh Jens, Gottwein Judith Margarete, Bieńkowska-Szewczyk Krystyna, Grzyb Katarzyna
Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk, 80-309 Gdańsk, Poland.
Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital, 2650 Hvidovre, Denmark.
Vaccines (Basel). 2020 Jun 10;8(2):294. doi: 10.3390/vaccines8020294.
Hepatitis C virus (HCV) infection with associated chronic liver diseases is a major health problem worldwide. Here, we designed hepatitis B virus (HBV) small surface antigen (sHBsAg) virus-like particles (VLPs) presenting different epitopes derived from the HCV E2 glycoprotein (residues 412-425, 434-446, 502-520, and 523-535 of isolate H77C). Epitopes were selected based on their amino acid sequence conservation and were previously reported as targets of HCV neutralizing antibodies. Chimeric VLPs obtained in the expression system, in combination with the adjuvant Addavax, were used to immunize mice. Although all VLPs induced strong humoral responses, only antibodies directed against HCV 412-425 and 523-535 epitopes were able to react with the native E1E2 glycoprotein complexes of different HCV genotypes in ELISA. Neutralization assays against genotype 1-6 cell culture infectious HCV (HCVcc), revealed that only VLPs carrying the 412-425 epitope induced efficient HCV cross-neutralizing antibodies, but with isolate specific variations in efficacy that could not necessarily be explained by differences in epitope sequences. In contrast, antibodies targeting 434-446, 502-520, and 523-535 epitopes were not neutralizing HCVcc, highlighting the importance of conformational antibodies for efficient virus neutralization. Thus, 412-425 remains the most promising linear E2 epitope for further bivalent, rationally designed vaccine research.
丙型肝炎病毒（HCV）感染及其相关的慢性肝病是全球主要的健康问题。在此，我们设计了乙型肝炎病毒（HBV）小表面抗原（sHBsAg）病毒样颗粒（VLPs），其呈现源自HCV E2糖蛋白（分离株H77C的第412 - 425、434 - 446、502 - 520和523 - 535位氨基酸）的不同表位。基于其氨基酸序列保守性选择表位，这些表位先前已被报道为HCV中和抗体的靶点。在表达系统中获得的嵌合VLPs与佐剂Addavax联合使用，用于免疫小鼠。尽管所有VLPs均诱导了强烈的体液免疫反应，但在酶联免疫吸附测定（ELISA）中，只有针对HCV 412 - 425和523 - 535表位的抗体能够与不同HCV基因型的天然E1E2糖蛋白复合物发生反应。针对1 - 6型细胞培养感染性HCV（HCVcc）的中和试验表明，只有携带412 - 425表位的VLPs诱导产生了有效的HCV交叉中和抗体，但在分离株特异性的效力上存在差异，这种差异不一定能用表位序列的不同来解释。相比之下，靶向434 - 446、502 - 520和523 - 535表位的抗体不能中和HCVcc，这突出了构象抗体对有效病毒中和的重要性。因此，412 - 425仍然是进一步进行二价、合理设计疫苗研究最有前景的线性E2表位。
