State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, 20 Dongdajie, Fengtai, Beijing 100071, China.
Vaccine. 2011 Aug 5;29(34):5645-51. doi: 10.1016/j.vaccine.2011.06.012. Epub 2011 Jun 29.
Early secreted antigenic target-6 (ESAT-6), an important Mycobacterium tuberculosis T-cell antigen, is an attractive candidate antigen for tuberculosis subunit vaccine development. Because ESAT-6 has a low inherent immunogenicity, we used Hepatitis B virus core (HBc) protein as an immune carrier to enhance ESAT-6 immunogenicity. The ESAT-6 gene was inserted into the major immunodominant region of the HBc molecule by fusion PCR. The recombinant protein, HBc-ESAT-6 (HE6), was expressed in Escherichia coli, and electron microscopy confirmed the formation of virus-like particles. The immunogenicity of the chimeric particles was assessed in mice. Serological assays and in vitro Th1-biased cytokine assays found that immunization with HE6 particles elicited significantly higher ESAT-6-specific antibodies and CD4⁺/CD8⁺ T cell responses in mice compared to immunization with recombinant ESAT-6 protein. These data demonstrate the feasibility of HBc particles serving as an efficient immune carrier for ESAT-6 and suggest that HE6 has potential for use in a tuberculosis subunit vaccine.
早期分泌抗原靶 6（ESAT-6）是结核分枝杆菌 T 细胞抗原的重要成分，是一种有吸引力的结核亚单位疫苗候选抗原。由于 ESAT-6 固有免疫原性较低，我们使用乙型肝炎病毒核心（HBc）蛋白作为免疫载体来增强 ESAT-6 的免疫原性。通过融合 PCR 将 ESAT-6 基因插入 HBc 分子的主要免疫显性区域。在大肠杆菌中表达重组蛋白 HBc-ESAT-6（HE6），电子显微镜证实形成了病毒样颗粒。在小鼠中评估嵌合颗粒的免疫原性。血清学检测和体外 Th1 偏向细胞因子检测发现，与免疫重组 ESAT-6 蛋白相比，用 HE6 颗粒免疫可在小鼠中诱导更高的 ESAT-6 特异性抗体和 CD4⁺/CD8⁺T 细胞反应。这些数据证明了 HBc 颗粒作为 ESAT-6 有效免疫载体的可行性，并表明 HE6 有潜力用于结核亚单位疫苗。
