PDF(Pubmed)
Abstract：
Identifying and evaluating potential vaccine candidates has become one of the main objectives to combat tuberculosis. Among them, mannosylated Apa antigen from Mycobacterium tuberculosis and the non-mannosylated protein expressed in Escherichia coli, have been studied. Although both proteins can induce a protective response in mice, it has been considered that native protein can be dispensed. In this work, we study the protective response induced by Apa expressed in E. coli and in Streptomyces lividans. The latter, like native is secreted as a double band of 45/47 kDa, however, only its 47 kDa band is mannosylated. Both antigens and BCG were intranasal administrated in mice, and animals were then challenged by aerosol with M. tuberculosis H37Rv. The results showed that both, Apa from S. lividans and E. coli conferred statistically significantly protection to animals compared to controls. The cytokine immune response was studied by an immunoassay after animals\' immunization, revealing that Apa from S. lividans induced a statistically significant proliferation of T cell, as well as the expression of IFN-γ, IL-1β, IL-17 and IL-10. In contrast, non-proliferation was obtained with non-mannosylated protein, but induction of IL-12 and IL-17 was observed. Together, these results demonstrate that both proteins were able to modulate a specific immune response against M. tuberculosis, that could be driven by different mechanisms possibly associated with the presence or not of mannosylation. Furthermore, stimulation of cells from BCG-vaccinated animals with the proteins could be an important tool, to help define the use of a given subunit-vaccine after BCG vaccination.
摘要：
识别和评估潜在的候选疫苗已成为抗击结核病的主要目标之一。其中,来自结核分枝杆菌的甘露糖基化Apa抗原和在大肠杆菌中表达的非甘露糖基化蛋白，已经研究过了。尽管这两种蛋白质都可以在小鼠中诱导保护性反应，已经认为天然蛋白质可以分配。在这项工作中,我们研究了在大肠杆菌和鱼链霉菌中表达的Apa诱导的保护反应。后者,像天然的一样被分泌为45/47kDa的双条带，然而,只有它的47kDa带是甘露糖基化的。抗原和BCG均在小鼠鼻内给药，然后用结核分枝杆菌H37Rv气雾剂攻击动物。结果表明,与对照相比,来自S.lividans和大肠杆菌的Apa赋予动物统计学上显著的保护。通过动物免疫后的免疫测定研究细胞因子免疫反应，揭示了来自S.lividans的Apa诱导了具有统计学意义的T细胞增殖，以及IFN-γ的表达，IL-1β,IL-17和IL-10。相比之下,用非甘露糖基化蛋白获得不增殖，但观察到IL-12和IL-17的诱导。一起,这些结果表明，两种蛋白质都能够调节针对结核分枝杆菌的特异性免疫反应，这可能是由可能与是否存在甘露糖基化相关的不同机制驱动的。此外，用蛋白质刺激接种BCG的动物的细胞可能是一个重要的工具，帮助确定BCG疫苗接种后给定亚单位疫苗的使用。
