Soares H R, Castro R, Tomás H A, Rodrigues A F, Gomes-Alves P, Bellier B, Klatzmann D, Carrondo M J T, Alves P M, Coroadinha A S
iBET - Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2780-901 Oeiras, Portugal; Instituto de Tecnologia Química e Biológica, António Xavier, Universidade Nova de Lisboa (ITQB-UNL), Av. da República, 2780-157 Oeiras, Portugal.
Sorbonne Universités, UPMC Univ Paris 06, UMRS_959, I3, F-75013 Paris, France; INSERM, UMR_S 959, I3, F-75013 Paris, France.
Vaccine. 2016 Mar 18;34(13):1634-1641. doi: 10.1016/j.vaccine.2015.12.015. Epub 2016 Jan 12.
Virus-like particles (VLPs) are a particular subset of subunit vaccines which are currently explored as safer alternatives to live attenuated or inactivated vaccines. VLPs derived from retrovirus (retroVLPs) are commonly used as scaffolds for vaccine candidates due to their ability to incorporate heterologous envelope proteins. Pseudotyping retroVLPs is however not a selective process therefore, host cellular proteins such as tetraspanins are also included in the membrane. The contribution of these host-proteins to retrovirus immunogenicity remains unclear. In this work, human cells silenced and not silenced for tetraspanin CD81 were used to produce CD81(-) or CD81(+) retroVLPs. We first analyzed mice immune response against human CD81. Despite effective silencing of CD81 in retroVLP producing cells, both humoral and cellular immune responses showed persistent anti-CD81 immunogenicity, suggesting cross reactivity to related antigens. We thus compared the incorporation of related tetraspanins in retroVLPs and showed that decreased CD81 incorporation in CD81(-) retro-VLPs is compensated by an increased incorporation of CD9 and CD63 tetraspanins. These results highlight the dynamic nature of host-derived proteins incorporation in retroVLPs membrane, which should be considered when retrovirus-based biopharmaceuticals are produced in xenogeneic cells.
病毒样颗粒（VLPs）是亚单位疫苗的一个特殊子集，目前正作为减毒活疫苗或灭活疫苗更安全的替代品进行研究。源自逆转录病毒的VLPs（逆转录病毒样颗粒，retroVLPs）由于能够整合异源包膜蛋白，常被用作候选疫苗的支架。然而，假型化逆转录病毒样颗粒不是一个选择性过程，因此，宿主细胞蛋白如四跨膜蛋白也包含在膜中。这些宿主蛋白对逆转录病毒免疫原性的贡献仍不清楚。在这项研究中，使用四跨膜蛋白CD81沉默和未沉默的人类细胞来生产CD81（-）或CD81（+）逆转录病毒样颗粒。我们首先分析了小鼠针对人CD81的免疫反应。尽管在产生逆转录病毒样颗粒的细胞中CD81有效沉默，但体液免疫和细胞免疫反应均显示出持续的抗CD81免疫原性，提示与相关抗原存在交叉反应。因此，我们比较了相关四跨膜蛋白在逆转录病毒样颗粒中的整合情况，结果显示CD81（-）逆转录病毒样颗粒中CD81整合的减少被CD9和CD63四跨膜蛋白整合的增加所补偿。这些结果突出了宿主来源蛋白整合到逆转录病毒样颗粒膜中的动态性质，在异源细胞中生产基于逆转录病毒的生物制药时应予以考虑。
