He Penghui, He Chunting, Wu Fuhua, Ou Yangsen, Luo Shuang, Zhang Yongshun, Chang Yu, Guo Zhaofei, Tang Xue, Zhao Yuanhao, Xu Yanhua, Wang Hairui, Bai Shuting, Du Guangsheng, Sun Xun
Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
J Control Release. 2025 Mar 10;379:1045-1057. doi: 10.1016/j.jconrel.2025.01.069. Epub 2025 Feb 5.
Adeno-associated viruses (AAV) have significant potential as vaccine carriers due to their excellent biosafety and efficient antigen gene delivery. However, most AAV vaccines show limited capacity to transduce antigen-presenting cells (APCs) following intramuscular injection which may cause inadequate cellular immune responses and undesired side effects due to transducing other tissues or cells. Herein, we developed a soluble microneedle patch for targeting the AAV vaccines to the epidermal and dermal APCs. To preserve the biological activity of the AAV vaccine, the microneedles were fabricated via an optimized two-step low-temperature strategy and using 20 % trehalose as a protective agent. AAV serotype 8, which expresses the trimeric receptor-binding domain (RBD) of the SARS-CoV-2 spike protein (AAV8-RBD), remained 100 % biological activity after being loaded into the microneedles (MN-A8R). Upon a single-dose vaccination on the dorsal skin of mice, MN-A8R efficiently recruited APCs to the vaccination site and improved AAV8-RBD infection in APCs. Furthermore, MN-A8R prompted an increased formation of germinal centers in the draining lymph nodes. Compared to hypodermic needle-mediated intradermal injection, MN-A8R induced significantly stronger cellular immune responses and long-lasting, high-quality neutralizing antibodies. Importantly, MN-A8R demonstrated more comprehensive and robust cross-protection against three common SARS-CoV-2 pseudoviruses for at least six months. Our findings highlight the use of optimized polymeric microneedles for preserving AAV vaccine biological activity and enhancing the AAV vaccine efficacy by up-regulating APC infection.
腺相关病毒（AAV）因其出色的生物安全性和高效的抗原基因递送能力，作为疫苗载体具有巨大潜力。然而，大多数AAV疫苗在肌肉注射后转导抗原呈递细胞（APC）的能力有限，这可能导致细胞免疫反应不足，以及因转导其他组织或细胞而产生不良副作用。在此，我们开发了一种可溶性微针贴片，用于将AAV疫苗靶向递送至表皮和真皮中的APC。为了保留AAV疫苗的生物活性，微针通过优化的两步低温策略制备，并使用20%的海藻糖作为保护剂。表达严重急性呼吸综合征冠状病毒2（SARS-CoV-2）刺突蛋白三聚体受体结合域（RBD）的AAV血清型8（AAV8-RBD），在加载到微针（MN-A8R）中后仍保持100%的生物活性。在小鼠背部皮肤进行单剂量疫苗接种后，MN-A8R有效地将APC招募到接种部位，并改善了AAV8-RBD在APC中的感染。此外，MN-A8R促使引流淋巴结中生发中心的形成增加。与皮下注射针介导的皮内注射相比，MN-A8R诱导的细胞免疫反应明显更强，且产生持久、高质量的中和抗体。重要的是，MN-A8R对三种常见的SARS-CoV-2假病毒表现出更全面、更强的交叉保护作用，且至少持续六个月。我们的研究结果突出了使用优化的聚合物微针来保留AAV疫苗生物活性，并通过上调APC感染来增强AAV疫苗疗效。
