Wussow Felix, Chiuppesi Flavia, Meng Zhuo, Martinez Joy, Nguyen Jenny, Barry Peter A, Diamond Don J
Department of Experimental Therapeutics, Beckman Research Institute of the City of Hope, Duarte, CA, USA.
Department of Experimental Therapeutics, Beckman Research Institute of the City of Hope, Duarte, CA, USA.
J Virol Methods. 2018 Jan;251:30-37. doi: 10.1016/j.jviromet.2017.10.006. Epub 2017 Oct 6.
Neutralizing antibodies (NAb) interfering with glycoprotein complex-mediated virus entry into host cells are thought to contribute to the protection against herpesvirus infection. However, using herpesvirus glycoprotein complexes as vaccine antigens can be complicated by the necessity of expressing multiple subunits simultaneously to allow efficient complex assembly and formation of conformational NAb epitopes. By using a novel bacterial artificial chromosome (BAC) clone of the clinically deployable Modified Vaccinia Ankara (MVA) vector and exploiting ribosomal skipping mediated by 2A peptides, MVA vectors were generated that expressed self-processing subunits of the human cytomegalovirus (HCMV) pentamer complex (PC) composed of gH, gL, UL128, UL130, and UL131A. These MVA vectors expressed 2A-linked HCMV PC subunits that were efficiently cleaved and transported to the cell surface as protein complexes forming conformational neutralizing epitopes. In addition, vaccination of mice by only two immunizations with these MVA vectors resulted in potent HCMV NAb responses that remained stable over a period of at least six months. This method of eliciting NAb by 2A-linked, self-processing HCMV PC subunits could contribute to develop a HCMV vaccine candidate and may serve as a template to facilitate the development of subunit vaccine strategies against other herpesviruses.
人们认为，干扰糖蛋白复合体介导的病毒进入宿主细胞的中和抗体（NAb）有助于预防疱疹病毒感染。然而，将疱疹病毒糖蛋白复合体用作疫苗抗原可能会很复杂，因为需要同时表达多个亚基，以实现有效的复合体组装和构象性NAb表位的形成。通过使用临床可用的改良痘苗病毒安卡拉（MVA）载体的新型细菌人工染色体（BAC）克隆，并利用由2A肽介导的核糖体跳跃，构建了表达人巨细胞病毒（HCMV）五聚体复合体（PC）自我加工亚基的MVA载体，该复合体由gH、gL、UL128、UL130和UL131A组成。这些MVA载体表达2A连接的HCMV PC亚基，这些亚基被有效切割并作为形成构象性中和表位的蛋白复合体转运到细胞表面。此外，用这些MVA载体仅对小鼠进行两次免疫接种就产生了强效的HCMV NAb反应，且在至少六个月的时间内保持稳定。这种通过2A连接的、自我加工的HCMV PC亚基引发NAb的方法可能有助于开发一种HCMV候选疫苗，并可作为促进针对其他疱疹病毒的亚单位疫苗策略开发的模板。
