Objectives Enhancement of the potential ability of biomacromolecules to cross cell membranes is a critical step for development of effective therapeutic vaccine especially DNA vaccine against human immunodeficiency virus-1 (HIV-1) infection. The supercharged proteins were known as powerful weapons for delivery of different types of cargoes such as DNA and protein. Hence, we applied B1 protein with + 43 net charges obtained from a single frameshift in the gene encoding enhanced green fluorescent protein (eGFP) for delivery of two multi-epitope DNA constructs ( nef - vpu - gp160 - p24 and nef - vif - gp160 - p24 ) in vitro and in vivo for the first time. For this purpose, B1 protein was generated in bacterial expression system under native conditions, and used to interact with both DNA constructs. Results Our data indicated that B1 protein (~ 27 kDa) was able to form a stable nanoparticle (~ 80–110 nm) with both DNA constructs at nitrogen: phosphate (N: P) ratio of 1:1. Moreover, the transfection efficiency of B1 protein for DNA delivery into HEK-293T cell line indicated that the cellular uptake of nef-vif-gp160-p24 DNA / B1 and nef-vpu-gp160-p24 DNA / B1 nanoparticles was about 32–35% with lower intensity as compared to TurboFect commercial reagent. On the other hand, immunization of BALB/c mice with different modalities demonstrated that B1 protein could enhance the levels of antibody, IFN-gamma and Granzyme B eliciting potent and strong Th1-directed cellular immunity. Conclusion Generally, our findings showed the potency of B1 protein as a promising gene delivery system to improve an effective therapeutic vaccine against HIV-1 infection.

中文翻译：

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B1 蛋白：一种用于 HIV-1 多表位 DNA 构建体的体外和体内递送的新型细胞穿透蛋白

目的 增强生物大分子穿越细胞膜的潜在能力是开发有效治疗性疫苗尤其是针对人类免疫缺陷病毒-1 (HIV-1) 感染的 DNA 疫苗的关键步骤。增压蛋白质被认为是运送不同类型货物（如 DNA 和蛋白质）的强大武器。因此，我们应用了从编码增强型绿色荧光蛋白 (eGFP) 的基因中的单个移码获得的 + 43 净电荷的 B1 蛋白，用于递送两个多表位 DNA 构建体 (nef - vpu - gp160 - p24 和 nef - vif - gp160 - p24 ) 首次在体外和体内。为此，在天然条件下在细菌表达系统中产生 B1 蛋白，并用于与两种 DNA 构建体相互作用。结果我们的数据表明，B1 蛋白（~ 27 kDa）能够形成稳定的纳米颗粒（~ 80-110 nm），其中两种 DNA 构建体的氮：磷酸盐（N：P）比例为 1:1。此外，B1蛋白将DNA导入HEK-293T细胞系的转染效率表明nef-vif-gp160-p24 DNA / B1和nef-vpu-gp160-p24 DNA / B1纳米颗粒的细胞摄取率约为32-35 % 与 TurboFect 商业试剂相比强度较低。另一方面，用不同方式对 BALB/c 小鼠进行免疫接种表明，B1 蛋白可以提高抗体、IFN-γ 和颗粒酶 B 的水平，从而引发强效的 Th1 定向细胞免疫。结论 一般来说，我们的研究结果表明 B1 蛋白作为一种有前途的基因传递系统的效力，可以改进针对 HIV-1 感染的有效治疗疫苗。