State Key Laboratory of Respiratory Diseases, Guangdong Laboratory of Computational Biomedicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.
Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, China.
J Virol. 2021 May 24;95(12). doi: 10.1128/JVI.00059-21.
Recombinant influenza A viral (IAV) vectors are potential to stimulate systemic and mucosal immunity, but the packaging capacity is limited and only one or a few epitopes can be carried. Here, we report the generation of a replication-competent IAV vector that carries a full-length HIV-1 gene linked to the 5'-terminal coding region of the neuraminidase segment via a protease cleavage sequence (IAV-p24). IAV-p24 was successfully rescued and stably propagated, and P24 protein was efficiently expressed in infected mammalian cells. In BALB/c mice, IAV-p24 showed attenuated pathogenicity compared to that of the parental A/PR/8/34 (H1N1) virus. An intranasal inoculation with IAV-p24 elicited moderate HIV-specific cell-mediated immune (CMI) responses in the airway and vaginal tracts and in the spleen, and an intranasal boost with a replication-incompetent adenovirus type 2 vector expressing the HIV-1 gene (Ad2-gag) greatly improved these responses. Importantly, compared to an Ad2-gag prime plus IAV-p24 boost regimen, the IAV-p24 prime plus Ad2-gag boost regimen had a greater efficacy in eliciting HIV-specific CMI responses. P24-specific CD8 T cells and antibodies were robustly provoked both systemically and in mucosal sites and showed long-term durability, revealing that IAV-p24 may be used as a mucosa-targeted priming vaccine. Our results illustrate that IAV-p24 is able to prime systemic and mucosal immunity against HIV-1 and warrants further evaluation in nonhuman primates. An effective HIV-1 vaccine remains elusive despite nearly 40 years of research. CD8 T cells and protective antibodies may both be desirable for preventing HIV-1 infection in susceptible mucosal sites. Recombinant influenza A virus (IAV) vector has the potential to stimulate these immune responses, but the packaging capacity is extremely limited. Here, we describe a replication-competent IAV vector expressing the HIV-1 gene (IAV-p24). Unlike most other IAV vectors that carried one or several antigenic epitopes, IAV-p24 stably expressed the full-length P24 protein, which contains multiple epitopes and is highly conserved among all known HIV-1 sequences. Compared to the parental A/PR/8/34 (H1N1) virus, IAV-p24 showed an attenuated pathogenicity in BALB/c mice. When combined with an adenovirus vector expressing the HIV-1 gene, IAV-p24 was able to prime P24-specific systemic and mucosal immune responses. IAV-p24 as an alternative priming vaccine against HIV-1 warrants further evaluation in nonhuman primates.
重组流感 A 病毒（IAV）载体具有刺激全身和黏膜免疫的潜力，但包装容量有限，只能携带一个或几个表位。在这里，我们报告了一种复制型 IAV 载体的产生，该载体通过蛋白酶切割序列将全长 HIV-1 基因连接到神经氨酸酶节段的 5'末端编码区（IAV-p24）。IAV-p24 成功挽救并稳定繁殖，感染的哺乳动物细胞中有效表达 P24 蛋白。在 BALB/c 小鼠中，与亲本 A/PR/8/34（H1N1）病毒相比，IAV-p24 表现出减弱的致病性。鼻内接种 IAV-p24 可在气道和阴道以及脾脏中引起适度的 HIV 特异性细胞介导免疫（CMI）反应，并用复制缺陷型腺病毒 2 型载体（表达 HIV-1 基因）进行鼻内加强接种（Ad2-gag）可大大提高这些反应。重要的是，与 Ad2-gag 初免加 IAV-p24 加强方案相比，IAV-p24 初免加 Ad2-gag 加强方案在引发 HIV 特异性 CMI 反应方面更有效。P24 特异性 CD8 T 细胞和抗体在全身和黏膜部位均被强烈引发，并具有长期的耐久性，表明 IAV-p24 可作为黏膜靶向的启动疫苗。我们的结果表明，IAV-p24 能够刺激针对 HIV-1 的全身和黏膜免疫，值得在非人类灵长类动物中进一步评估。尽管经过近 40 年的研究，仍未能开发出有效的 HIV-1 疫苗。CD8 T 细胞和保护性抗体对于预防易感染的黏膜部位的 HIV-1 感染可能都是理想的。重组流感 A 病毒（IAV）载体具有刺激这些免疫反应的潜力，但包装容量极其有限。在这里，我们描述了一种表达 HIV-1 基因（IAV-p24）的复制型 IAV 载体。与大多数携带一个或几个抗原表位的其他 IAV 载体不同，IAV-p24 稳定表达全长 P24 蛋白，该蛋白包含多个表位，并且在所有已知的 HIV-1 序列中高度保守。与亲本 A/PR/8/34（H1N1）病毒相比，IAV-p24 在 BALB/c 小鼠中表现出减弱的致病性。当与表达 HIV-1 基因的腺病毒载体结合使用时，IAV-p24 能够引发 P24 特异性全身和黏膜免疫反应。IAV-p24 作为 HIV-1 的替代启动疫苗值得在非人类灵长类动物中进一步评估。
