BACKGROUND The persistence, biodistribution, and risk of integration into the host genome of any new therapeutic DNA vaccine must be established in preclinical studies. We previously developed the DNA vaccine pcDNA-CCOL2A1 encoding chicken type II collagen (CCII) for the treatment of rheumatoid arthritis (RA). In the present study, we characterized its dynamic profile, biodistribution, and potential for genomic DNA integration in normal vaccinated rodent. RESULTS A real-time quantitative PCR analysis (RT-qPCR) of animals administered a single dose of pcDNA-CCOL2A1 (300 μg/kg by intramuscular injection) showed that CCOL2A1 mRNA level in the blood peaked between 2 and 6 h post-immunization and then rapidly declined, and was undetectable between day 1-42. CCOL2A1 transcript was detected at the muscle injection site on days 3-14 post-immunization. Starting from day 14, the transcript was detected in the heart, liver, lung, and kidney but not in the spleen or thymus, and was expressed only in the lung on day 28. There was no CCOL2A1 mRNA present in the testes or ovaries at any time point. Non-invasive in vivo fluorescence imaging revealed CCII protein expression from 2 h up to day 10 and from 2 h up to day 35 after administration of pcDNA-CCOL2A1 via the intravenous and intramuscular routes, respectively; the protein had disappeared by day 42. Importantly, CCOL2A1 was not integrated into the host genome. CONCLUSIONS These results indicate that pcDNA-CCOL2A1 vaccine is rapidly cleared within a short period of time and is therefore safe, and merits further development as a therapeutic vaccine for RA treatment.

中文翻译：

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编码鸡 II 型胶原蛋白的新型治疗性 DNA 疫苗在已接种疫苗的正常啮齿动物中进行肌肉/静脉注射治疗类风湿性关节炎后的动态特征、生物分布和整合评估。


背景任何新的治疗性 DNA 疫苗的持久性、生物分布和整合到宿主基因组中的风险都必须在临床前研究中确定。我们之前开发了编码鸡 II 型胶原蛋白 (CCII) 的 DNA 疫苗 pcDNA-CCOL2A1，用于治疗类风湿性关节炎 (RA)。在本研究中，我们表征了其在正常接种疫苗的啮齿动物中的动态特征、生物分布和基因组 DNA 整合的潜力。结果 对单剂量 pcDNA-CCOL2A1（肌肉注射 300 μg/kg）的动物进行实时定量 PCR 分析（RT-qPCR）显示，血液中 CCOL2A1 mRNA 水平在免疫后 2 至 6 小时内达到峰值，并且然后迅速下降，并在第 1-42 天之间检测不到。免疫后第 3-14 天在肌肉注射部位检测到 CCOL2A1 转录物。从第14天开始，在心脏、肝脏、肺和肾脏中检测到转录本，但在脾脏或胸腺中没有检测到，并且在第28天仅在肺中表达。在第28天，睾丸或卵巢中不存在CCOL2A1 mRNA。任何时间点。非侵入性体内荧光成像显示分别通过静脉内和肌内途径施用pcDNA-CCOL2A1后2小时至10天和2小时至35天的CCII蛋白表达；该蛋白质在第 42 天就消失了。重要的是，CCOL2A1 没有整合到宿主基因组中。结论这些结果表明pcDNA-CCOL2A1疫苗在短时间内被迅速清除，因此是安全的，值得进一步开发作为RA治疗的治疗性疫苗。