Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Institution of Pathogenic Biology, Hengyang Medical College, University of South China, Hengyang 421001, People's Republic of China.
Department of Health Services, Air Force Medical University, Xi'an, Shaanxi 710032, People's Republic of China.
Int J Nanomedicine. 2019 Aug 16;14:6601-6613. doi: 10.2147/IJN.S206210. eCollection 2019.
The primary goal of the present study was to explore and evaluate the highly conserved Neisserial surface protein A (NspA) molecule, fused with truncated HBV virus-like particles (VLPs), as a candidate vaccine against the virulent serogroup B (NMB).
NspA was inserted into the major immunodominant region of the truncated hepatitis B virus core protein (HBc; amino acids 1-144). The chimeric protein, HBc-N144-NspA, was expressed from a prokaryotic vector and generated HBc-like particles, as determined by transmission electron microscopy. Further, the chimeric protein and control proteins were used to immunize mice and the resulting immune responses evaluated by flow cytometry, enzyme-linked immunosorbent assay, and analysis of serum bactericidal activity (SBA) titer.
Evaluation of the immunogenicity of the recombinant HBc-N144-NspA protein showed that it elicited the production of high levels of NspA-specific total IgG. The SBA titer of HBc-N144-NspA/F reached 1:16 2 weeks after the last immunization in BALB/c mice, when human serum complement was included in the vaccine. Immunization of HBc-N144-NspA, even without adjuvant, induced high levels of IL-4 and a high IgG1 to IgG2a ratio, confirming induction of an intense Th2 immune response. Levels of IL-17A increased rapidly in mice after the first immunization with HBc-N144-NspA, indicating the potential for this vaccine to induce a mucosal immune response. Meanwhile, the immunization of HBc-N144-NspA without adjuvant induced only mild inflammatory infiltration into the mouse muscle tissue.
This study demonstrates that modification using HBc renders NspA a candidate vaccine, which can trigger protective immunity against NMB.
本研究的主要目的是探索和评估高度保守的奈瑟氏表面蛋白 A（NspA）与截短的乙型肝炎病毒样颗粒（VLPs）融合的分子，作为针对毒力血清组 B（NMB）的候选疫苗。
将 NspA 插入乙型肝炎病毒核心蛋白（HBc；氨基酸 1-144）的主要免疫显性区域。通过透射电子显微镜确定，嵌合蛋白 HBc-N144-NspA 从原核载体表达并产生 HBc 样颗粒。进一步，用嵌合蛋白和对照蛋白免疫小鼠，通过流式细胞术、酶联免疫吸附试验和血清杀菌活性（SBA）滴度分析评估产生的免疫应答。
对重组 HBc-N144-NspA 蛋白的免疫原性评估表明，它引起了高水平的 NspA 特异性总 IgG 的产生。当人类血清补体包含在疫苗中时，HBc-N144-NspA/F 的 SBA 滴度在 BALB/c 小鼠最后一次免疫后 2 周达到 1:16。即使没有佐剂，HBc-N144-NspA 的免疫也诱导了高水平的 IL-4 和 IgG1 与 IgG2a 的高比值，证实了强烈的 Th2 免疫应答的诱导。HBc-N144-NspA 初次免疫后，IL-17A 在小鼠中的水平迅速增加，表明该疫苗具有诱导黏膜免疫应答的潜力。同时，HBc-N144-NspA 无佐剂免疫仅引起小鼠肌肉组织的轻度炎症浸润。
本研究表明，使用 HBc 修饰使 NspA 成为候选疫苗，可引发针对 NMB 的保护性免疫。
