Gummow Jason, Masavuli Makutiro G, Mekonnen Zelalem A, Li Yanrui, Wijesundara Danushka K, Shrestha Ashish C, Voskoboinik Ilia, Gowans Eric J, Grubor-Bauk Branka
Virology Laboratory, Discipline of Surgery, The University of Adelaide and Basil Hetzel Institute for Translational Health Research, Adelaide 5011, Australia.
Gene Silencing and Expression Laboratory, Robinson Research Institute, The University of Adelaide, Adelaide 5000, Australia.
Vaccines (Basel). 2020 Jan 29;8(1):53. doi: 10.3390/vaccines8010053.
Despite direct acting antivirals (DAAs) curing >95% of individuals infected with hepatitis C (HCV), in order to achieve the World Health Organization HCV Global Elimination Goals by 2030 there are still major challenges that need to be overcome. DAAs alone are unlikely to eliminate HCV in the absence of a vaccine that can limit viral transmission. Consequently, a prophylactic HCV vaccine is necessary to relieve the worldwide burden of HCV disease. DNA vaccines are a promising vaccine platform due to their commercial viability and ability to elicit robust T-cell-mediated immunity (CMI). We have developed a novel cytolytic DNA vaccine that encodes non-structural HCV proteins and a truncated mouse perforin (PRF), which is more immunogenic than the respective canonical DNA vaccine lacking PRF. Initially we assessed the ability of the HCV pNS3-PRF and pNS4/5-PRF DNA vaccines to elicit robust long-term CMI without any adverse side-effects in mice. Interferon-γ (IFN-γ) enzyme-linked immunosorbent spot (ELISpot) assay was used to evaluate CMI against NS3, NS4 and NS5B in a dose-dependent manner. This analysis showed a dose-dependent bell-curve of HCV-specific responses in vaccinated animals. We then thoroughly examined the effects associated with reactogenicity of cytolytic DNA vaccination with the multi-antigenic HCV DNA vaccine (pNS3/4/5B). Hematological, biochemical and histological studies were performed in male Sprague Dawley rats with a relative vaccine dose 10-20-fold higher than the proposed dose in Phase I clinical studies. The vaccine was well tolerated, and no toxicity was observed. Thus, the cytolytic multi-antigenic DNA vaccine is safe and elicits broad memory CMI.
尽管直接作用抗病毒药物（DAAs）能治愈超过95%的丙型肝炎（HCV）感染者，但为了在2030年前实现世界卫生组织的HCV全球消除目标，仍有一些重大挑战需要克服。在没有可限制病毒传播的疫苗的情况下，仅靠DAAs不太可能消除HCV。因此，一种预防性HCV疫苗对于减轻全球HCV疾病负担是必要的。DNA疫苗因其商业可行性和引发强大的T细胞介导免疫（CMI）的能力而成为一种有前景的疫苗平台。我们开发了一种新型溶细胞DNA疫苗，其编码非结构HCV蛋白和截短的小鼠穿孔素（PRF），它比缺乏PRF的相应经典DNA疫苗更具免疫原性。最初，我们评估了HCV pNS3-PRF和pNS4/5-PRF DNA疫苗在小鼠中引发强大的长期CMI且无任何不良副作用的能力。使用干扰素-γ（IFN-γ）酶联免疫斑点（ELISpot）测定法以剂量依赖方式评估针对NS3、NS4和NS5B的CMI。该分析显示接种疫苗动物中HCV特异性反应呈剂量依赖性钟形曲线。然后，我们用多抗原HCV DNA疫苗（pNS3/4/5B）全面检查了溶细胞DNA疫苗接种的反应原性相关影响。对雄性Sprague Dawley大鼠进行了血液学、生化和组织学研究，其相对疫苗剂量比I期临床研究中提议的剂量高10 - 20倍。该疫苗耐受性良好，未观察到毒性。因此，溶细胞多抗原DNA疫苗是安全的，并能引发广泛的记忆CMI。
