Gordeychuk Ilya, Kyuregyan Karen, Kondrashova Alla, Bayurova Ekaterina, Gulyaev Stanislav, Gulyaeva Tatiana, Potemkin Ilya, Karlsen Anastasia, Isaeva Olga, Belyakova Alla, Lyashenko Anna, Sorokin Alexey, Chumakov Alexey, Morozov Igor, Isaguliants Maria, Ishmukhametov Aydar, Mikhailov Mikhail
Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, Moscow 108819, Russia; Institute for Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, Moscow 127994, Russia.
Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, Moscow 108819, Russia; I.I. Mechnikov Research Institute of Vaccines and Sera, Moscow 105064, Russia; Russian Medical Academy of Continuous Professional Education, Moscow 125993, Russia.
Vaccine. 2022 Jan 3;40(1):89-99. doi: 10.1016/j.vaccine.2021.11.042. Epub 2021 Nov 24.
Hepatitis E virus (HEV) is a major causative agent of acute hepatitis worldwide, prompting continuous HEV vaccine efforts. Vaccine development is hampered by the lack of convenient animal models susceptible to infection with different HEV genotypes. We produced recombinant open reading frame 2 protein (pORF2; p551) of HEV genotype (GT) 3 and assessed its immunogenicity and protectivity against HEV challenge in common marmosets (Callithrix jacchus, CM).
p551 with consensus sequence corresponding to amino acid residues 110-660 of HEV GT3 pORF2 was expressed in E. coli and purified by affinity chromatography. CMs were immunized intramuscularly with 20 μg of p551 VLPs with alum adjuvant (n = 4) or adjuvant alone (n = 2) at weeks 0, 3, 7 and 19. At week 27, p551-immunized and control animals were challenged with HEV GT1 or GT3 and thereafter longitudinally screened for markers of liver function, anti-HEV IgG and HEV RNA in feces and sera.
Purified p551 formed VLPs with particle size of 27.71 ± 2.42 nm. Two immunizations with p551 induced anti-HEV IgG mean titer of 1:1810. Immunized CMs challenged with homologous and heterologous HEV genotype did not develop HEV infection during the follow-up. Control CMs infected with both HEV GT1 and GT3 demonstrated signs of HEV infection with virus shedding and elevation of the levels of liver enzymes. High levels of anti-HEV IgG persisted in vaccinated CMs and control CMs that resolved HEV infection, for up to two years post challenge.
CMs are shown to be a convenient laboratory animal model susceptible to infection with HEV GT1 and GT3. Immunization with HEV GT3 ORF2/p551 triggers potent anti-HEV antibody response protecting CMs from homologous and heterologous HEV challenge. This advances p551 in VLPs as a prototype vaccine against HEV.
戊型肝炎病毒（HEV）是全球急性肝炎的主要病原体，促使人们不断努力研发戊型肝炎疫苗。由于缺乏对不同基因型HEV感染敏感的便捷动物模型，疫苗研发受到阻碍。我们制备了戊型肝炎病毒基因型（GT）3的重组开放阅读框2蛋白（pORF2；p551），并评估了其在普通狨猴（Callithrix jacchus，CM）中对HEV攻击的免疫原性和保护作用。
具有与HEV GT3 pORF2氨基酸残基110 - 660相对应的共有序列的p551在大肠杆菌中表达，并通过亲和层析纯化。普通狨猴在第0、3、7和19周时，分别用20μg含明矾佐剂的p551病毒样颗粒（n = 4）或单独的佐剂（n = 2）进行肌肉注射免疫。在第27周时，对p551免疫的动物和对照动物用HEV GT1或GT3进行攻击，然后纵向检测肝功能指标、粪便和血清中的抗HEV IgG以及HEV RNA。
纯化的p551形成了粒径为27.71±2.42nm的病毒样颗粒。两次接种p551诱导的抗HEV IgG平均滴度为1:1810。用同源和异源HEV基因型攻击的免疫普通狨猴在随访期间未发生HEV感染。感染HEV GT1和GT3的对照普通狨猴表现出HEV感染的迹象，伴有病毒排出和肝酶水平升高。在接种疫苗的普通狨猴和清除HEV感染的对照普通狨猴中，高水平的抗HEV IgG持续存在，直至攻击后两年。
普通狨猴被证明是一种对HEV GT1和GT3感染敏感的便捷实验动物模型。用HEV GT3 ORF2/p551免疫可引发有效的抗HEV抗体反应，保护普通狨猴免受同源和异源HEV攻击。这推动了p551作为抗HEV原型疫苗的发展。
