Institute of Pathogenic Biology, Hengyang Medical College, University of South China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang 421001, China.
Institute of Pathogenic Biology, Hengyang Medical College, University of South China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang 421001, China; Department of Blood Transfusion, the First Affiliated Hospital of University of South China, Hengyang 421001, China.
Immunobiology. 2021 May;226(3):152077. doi: 10.1016/j.imbio.2021.152077. Epub 2021 Mar 24.
Mycoplasma pneumoniae is the most common pathogen of community-acquired pneumonia in humans. Due to its high rates of antibiotic resistance, vaccination has become the best method to control the dissemination of M. pneumoniae. The recombinant carboxyl terminus of the P1 (P1C) protein is an immunodominant antigen, but it has negative effects such as poor stability and lower purity. In the current study, T-B epitopes of the P1C protein were predicted according to bioinformatics analysis and assessed for efficacy in peptide vaccination. BALB/c mice were subcutaneously inoculated with the T-B epitope peptides four times and then infected with M. pneumoniae through the respiratory tract. The results showed that the T-B epitope peptides of the P1C protein (P1C, P1C, P1C and P1C) induced strong antigen-specific serum antibody responses and cellular immune responses with high levels of serum IgG, IgA antibodies and Th1-biased (IFN-γ and IL-2) cytokines. Immunization with T-B epitope peptides significantly reduced the M. pneumoniae burden and the degree of inflammation in the challenged mice. Furthermore, the levels of IFN-γ and TNF-α in the supernatants of lung homogenates were observably reduced compared to those in the PBS group. Overall, our findings demonstrate that T-B epitopes (P1C, P1C, P1C and P1C) play significant roles in the P1C protein and can be used to induce powerful humoral and cellular immune responses to provide significant protection against M. pneumoniae pulmonary infection, which provides new insight into the design of potential multiepitope vaccines to prevent host infection by M. pneumoniae.
肺炎支原体是人类社区获得性肺炎最常见的病原体。由于其抗生素耐药率高，疫苗接种已成为控制肺炎支原体传播的最佳方法。P1 的羧基末端重组蛋白（P1C）是一种免疫优势抗原，但它具有稳定性差、纯度低等缺点。在本研究中，根据生物信息学分析预测了 P1C 蛋白的 T-B 表位，并评估了其在肽疫苗接种中的效果。BALB/c 小鼠经皮接种 T-B 表位肽 4 次，然后通过呼吸道感染肺炎支原体。结果表明，P1C 蛋白的 T-B 表位肽（P1C、P1C、P1C 和 P1C）诱导了强烈的抗原特异性血清抗体反应和细胞免疫反应，血清 IgG、IgA 抗体和 Th1 偏向（IFN-γ 和 IL-2）细胞因子水平较高。T-B 表位肽免疫显著降低了 challenged 小鼠中的肺炎支原体负荷和炎症程度。此外，与 PBS 组相比，肺匀浆上清液中 IFN-γ 和 TNF-α 的水平明显降低。总之，我们的研究结果表明，T-B 表位（P1C、P1C、P1C 和 P1C）在 P1C 蛋白中发挥重要作用，可以诱导强大的体液和细胞免疫反应，为预防肺炎支原体肺部感染提供了显著保护，为设计预防肺炎支原体宿主感染的潜在多表位疫苗提供了新的思路。
