State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen, 361102, China.
National Institute of Diagnostics and Vaccine Development in Infectious Disease, School of Life Sciences, Xiamen University, Xiamen, 361102, China.
Protein J. 2018 Apr;37(2):194-202. doi: 10.1007/s10930-018-9763-0.
Human immunodeficiency virus type 1 (HIV-1) has been a global epidemic since 1983; yet, the virology and immunology related to HIV-1 remain elusive. Furthermore, as there is still no effective chemoprophylaxis or vaccine to treat patients with HIV-1, most research focuses on strategies to prevent HIV-1 infection, such as with antiviral drugs, novel therapeutics, or improved diagnostic kits. The HIV-1 Gag precursor protein (p55)-comprising the matrix (MA/p17), capsid (CA/p24), and nucleocapsid (NC/p7) protein domains-is the main structural HIV-1 protein, and is uniquely responsible for virion assembly within the virus life cycle. Recently, the immature and mature capsid structures were solved; however, the precursor protein structure is still unknown. Here, we expressed two subtypes of HIV-1 MA-CA stretch of the Gag protein, referred to as p41, in a bacterial expression system. We characterized the purified p41 protein, and showed its superior antigenicity over that of p24, highlighting the potential influence of the p17 domain on p24 structure. We further showed that p41 has good immunogenicity to induce an antibody response in mice. These results will aid future investigations into the HIV-1 capsid precursor structure, and potentially contribute to improving the design of diagnostic kits.
人类免疫缺陷病毒 1 型（HIV-1）自 1983 年以来一直是全球流行的疾病；然而，与 HIV-1 相关的病毒学和免疫学仍然难以捉摸。此外，由于目前仍然没有有效的化学预防或疫苗来治疗 HIV-1 患者，因此大多数研究都集中在预防 HIV-1 感染的策略上，例如使用抗病毒药物、新型疗法或改进的诊断试剂盒。HIV-1 Gag 前体蛋白（p55）包含基质（MA/p17）、衣壳（CA/p24）和核衣壳（NC/p7）蛋白结构域，是主要的 HIV-1 结构蛋白，负责病毒生命周期中病毒粒子的组装。最近，不成熟和成熟的衣壳结构已经被解决；然而，前体蛋白结构仍然未知。在这里，我们在细菌表达系统中表达了 HIV-1 MA-CA 延伸的 Gag 蛋白的两种亚型，称为 p41。我们对纯化的 p41 蛋白进行了表征，并表明其抗原性优于 p24，突出了 p17 结构域对 p24 结构的潜在影响。我们进一步表明，p41 具有良好的免疫原性，可以在小鼠中诱导抗体反应。这些结果将有助于未来对 HIV-1 衣壳前体结构的研究，并可能有助于改进诊断试剂盒的设计。
