Development of DC-vaccine against tuberclulosis

发展针对细胞内病原体的有效疫苗策略是当前医学研究的主要前沿之一。由于树突状细胞(DC)是启动初始免疫反应的最强大的抗原提呈细胞，它们可能是针对细胞内病原体的保护性免疫的重要组成部分。在本研究中，我们试图开发针对单核细胞增生性李斯特氏菌(Listeria monuctogenes，LM)的转基因DC疫苗，这是一种兼性细胞内病原体。此外，我们还检测了基因修饰的DC疫苗的效力，并与DNA疫苗进行了比较。用编码溶血素O(LLO)91-99的基因逆转录转化小鼠骨髓来源的DC，LLO 91-99是一种由LM产生的溶血素，是抗李氏杆菌免疫的H-2K^d限制性靶向免疫优势表位。将转导的DC静脉注射免疫幼龄BALB/c小鼠。DNA免疫，用基因枪皮下注射编码LLO 91-99的质粒。我们发现，专门设计的表达LLO91-99的DC疫苗可以有效地产生具有强大细胞毒活性和干扰素-γ的多肽特异性CD8+T细胞，从而诱导对LM的强大保护性免疫。此外，DC疫苗在诱导抗李斯特菌免疫方面比DNA疫苗更有效。这些数据表明，表达单一免疫优势表位的基因修饰DC疫苗对细胞内病原体感染是有用的，并且可能优于DNA疫苗，为针对细胞内病原体的疫苗设计提供了一种替代策略。

The development of effective vaccine strategies for intracellular pathogens is one of major frontiers of current medical research. As dendritic cells (DCs) are the most potent antigen-presenting cells that initiate the primary immune response, they may provide an essential component of protective immunity against intracellular pathogens. In the present study, we attempted to develop genetically modified DC-based vaccine against Listeria monocytogenes (Lm), a facultative intracellular pathogen. Further, we determined the efficacy of the gene modified DC vaccine and also compared it with that of DNA vaccine. Murine bone marrow-derived DCs were retrovirally transduced with cDNA encoding lysteriolysin O (LLO) 91-99, a hemolysin produced by Lm, that is a H-2K^d-restricted target immunodominant epitope of antilisterial immunity. Naive BALB/c mice were immunized by intravenous injection of the transduced DCs. For DNA immunizaton, plasmid encoding LLO 91-99 was subcutaneouly injected using a gene gun. We found that specifically designed DC vaccine to express LLO 91-99 could effectively generate peptide-specific CD8+ T cells exhibiting strong cytotoxic activity and IFN-γ production, leading to induction of potent protective immunity against Lm. Furthermore, the DC-based vaccine was more effective than the DNA vaccine at eliciting anti-listerial immunity. These data suggest that gene modified DC vaccine expressing a single immunodominant epitope is useful for intracellular pathogen infection and may be superior to DNA vaccine, providing an alternative strategy for vaccine design against intracellular pathogens.