Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, United States.
Department of Microbiology and Immunology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt.
Front Immunol. 2023 Jun 8;14:1188754. doi: 10.3389/fimmu.2023.1188754. eCollection 2023.
The induction of an effective immune response is critical for the success of mRNA-based therapeutics. Here, we developed a nanoadjuvant system compromised of Quil-A and DOTAP (dioleoyl 3 trimethylammonium propane), hence named QTAP, for the efficient delivery of mRNA vaccine constructs into cells. Electron microscopy indicated that the complexation of mRNA with QTAP forms nanoparticles with an average size of 75 nm and which have ~90% encapsulation efficiency. The incorporation of pseudouridine-modified mRNA resulted in higher transfection efficiency and protein translation with low cytotoxicity than unmodified mRNA. When QTAP-mRNA or QTAP alone transfected macrophages, pro-inflammatory pathways (e.g., NLRP3, NF-kb, and MyD88) were upregulated, an indication of macrophage activation. In C57Bl/6 mice, QTAP nanovaccines encoding Ag85B and Hsp70 transcripts (QTAP-85B+H70) were able to elicit robust IgG antibody and IFN- ɣ, TNF-α, IL-2, and IL-17 cytokines responses. Following aerosol challenge with a clinical isolate of significant reduction of mycobacterial counts was observed in lungs and spleens of only immunized animals at both 4- and 8-weeks post-challenge. As expected, reduced levels of were associated with diminished histological lesions and robust cell-mediated immunity. Interestingly, polyfunctional T-cells expressing IFN- ɣ, IL-2, and TNF- α were detected at 8 but not 4 weeks post-challenge. Overall, our analysis indicated that QTAP is a highly efficient transfection agent and could improve the immunogenicity of mRNA vaccines against pulmonary , an infection of significant public health importance, especially to the elderly and to those who are immune compromised.
有效的免疫应答诱导对于基于 mRNA 的治疗药物的成功至关重要。在这里，我们开发了一种由 Quil-A 和 DOTAP（二油酰基 3 三甲基铵丙烷）组成的纳米佐剂系统，因此将其命名为 QTAP，用于将 mRNA 疫苗构建体有效递送至细胞。电子显微镜表明，mRNA 与 QTAP 的复合物形成平均大小为 75nm 的纳米颗粒，其包封效率约为 90%。与未修饰的 mRNA 相比，包含假尿嘧啶修饰的 mRNA 可提高转染效率和蛋白翻译，同时细胞毒性较低。当 QTAP-mRNA 或 QTAP 单独转染巨噬细胞时，促炎途径（例如 NLRP3、NF-kb 和 MyD88）上调，表明巨噬细胞被激活。在 C57Bl/6 小鼠中，编码 Ag85B 和 Hsp70 转录物的 QTAP 纳米疫苗（QTAP-85B+H70）能够引发强烈的 IgG 抗体和 IFN-γ、TNF-α、IL-2 和 IL-17 细胞因子反应。在气溶胶挑战后，仅在免疫动物的肺部和脾脏中观察到临床分离株的细菌计数显著减少，在挑战后 4 周和 8 周均观察到这一现象。正如预期的那样，与组织学病变减轻和强大的细胞介导免疫相关的是 水平降低。有趣的是，在 8 周而不是 4 周时检测到表达 IFN-γ、IL-2 和 TNF-α 的多功能 T 细胞。总体而言，我们的分析表明，QTAP 是一种高效的转染剂，可以提高针对肺部 的 mRNA 疫苗的免疫原性，这是一种具有重要公共卫生意义的感染，尤其是对老年人和免疫功能低下的人。
