Baculovirus has been exploited for use as a novel vaccine vector. To investigate the feasibility and efficacy of recombinant baculoviruses (rBVs) expressing respiratory syncytial virus (RSV) fusion (F) proteins, four constructs (Bac-tF/64, Bac-CF, Bac-CF/tF64 and Bac-CF/tF64-VISA) were generated. Bac-tF64 displays the F ectodomain (tF) on the envelope of rBVs, whereas Bac-CF expresses full-length F protein in transduced mammalian cells. Bac-CF/tF64 not only displays tF on the envelope but also expresses F in cells. Bac-CF/tF64-VISA comprises Bac-CF/tF64 harboring the virus-induced signaling adaptor (VISA) gene. After administration to BALB/c mice, all four vectors elicited RSV neutralizing antibody (Ab), systemic Ab (IgG, IgG1, and IgG2a), and cytokine responses. Compared with Bac-tF64, mice inoculated with Bac-CF and Bac-CF/tF64 exhibited an increased mixed Th1/Th2 cytokine response, increased ratios of IgG2a/IgG1 antibody responses, and reduced immunopathology upon RSV challenge. Intriguingly, co-expression of VISA reduced Th2 cytokine (IL-4, IL-5, and IL-10) production induced by Bac-CF/tF64, thus relieving lung pathology upon a subsequent RSV challenge. Our results indicated that the Bac-CF/tF64 vector incorporated with the VISA molecule may provide an effective vaccine strategy for protection against RSV.

中文翻译：

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表达F蛋白的杆状病毒载体与病毒诱导的信号衔接子（VISA）分子结合，可预防呼吸道合胞病毒感染。

杆状病毒已被开发用作新型疫苗载体。为了研究表达呼吸道合胞病毒（RSV）融合（F）蛋白的重组杆状病毒（rBV）的可行性和功效，使用了四种构建体（Bac-tF / 64，Bac-CF，Bac-CF / tF64和Bac-CF / tF64- VISA）。Bac-tF64在rBV的外壳上显示F胞外域（tF），而Bac-CF在转导的哺乳动物细胞中表达全长F蛋白。Bac-CF / tF64不仅在信封上显示tF，而且还在细胞中表达F。Bac-CF / tF64-VISA包含Bac-CF / tF64，带有病毒诱导的信号转接头（VISA）基因。给BALB / c小鼠给药后，所有四个载体均引发RSV中和抗体（Ab），全身性Ab（IgG，IgG1和IgG2a）和细胞因子应答。与Bac-tF64相比，接种Bac-CF和Bac-CF / tF64的小鼠表现出增加的Th1 / Th2细胞因子混合应答，IgG2a / IgG1抗体应答比率增加以及RSV攻击后免疫病理降低。有趣的是，VISA的共表达减少了由Bac-CF / tF64诱导的Th2细胞因子（IL-4，IL-5和IL-10）的产生，从而减轻了随后RSV攻击后的肺部病变。我们的结果表明，与VISA分子结合的Bac-CF / tF64载体可为保护RSV提供有效的疫苗策略。