Health Sciences North Research Institute, 56 Walford Road, Sudbury, ON P3E 2H3, Canada.
Department of Biology, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON P3E 2C6, Canada.
Molecules. 2020 Mar 12;25(6):1290. doi: 10.3390/molecules25061290.
The addictive nature of nicotine is likely the most significant reason for the continued prevalence of tobacco smoking despite the widespread reports of its negative health effects. Nicotine vaccines are an alternative to the currently available smoking cessation treatments, which have limited efficacy. However, the nicotine hapten is non-immunogenic, and successful vaccine formulations to treat nicotine addiction require both effective adjuvants and delivery systems. The immunomodulatory properties of short, non-natural peptide sequences not found in human systems and their ability to improve vaccine efficacy continue to be reported. The aim of this study was to determine if small "non-natural peptides," as part of a conjugate nicotine vaccine, could improve immune responses. Four peptides were synthesized via solid phase methodology, purified, and characterized. plasma stability studies using RP-HPLC confirmed that the peptides were not subject to proteolytic degradation. The peptides were formulated into conjugate nicotine vaccine candidates along with a bacterial derived adjuvant vaccine delivery system and chitosan as a stabilizing compound. Formulations were tested in a dendritic cell line to determine the combination that would elicit the greatest 1L-1β response using ELISAs. Three of the peptides were able to enhance the cytokine response above that induced by the adjuvant delivery system alone. vaccination studies in BALB/c mice demonstrated that the best immune response, as measured by nicotine-specific antibody levels, was elicited from the conjugate vaccine structure, which included the peptide, as well as the other components. Isotype analyses highlighted that the peptide was able to shift immune response toward being more humorally dominant. Overall, the results have implications for the use of non-natural peptides as adjuvants not only for the development of a nicotine vaccine but also for use with other addictive substances and conventional vaccination targets as well.
尼古丁的成瘾性可能是尽管有广泛的报道称其对健康有负面影响，但烟草仍继续流行的最主要原因。尼古丁疫苗是目前可用的戒烟治疗方法的替代品，这些方法的疗效有限。然而，尼古丁半抗原无免疫原性，成功的治疗尼古丁成瘾的疫苗配方需要有效的佐剂和递送系统。短的、非天然肽序列的免疫调节特性在人类系统中不存在，并且它们能够提高疫苗的功效，这一点仍在不断得到报道。本研究的目的是确定作为共轭尼古丁疫苗的一部分的小“非天然肽”是否可以改善免疫反应。通过固相法合成了 4 种肽，经纯化和表征。使用 RP-HPLC 进行的 血浆稳定性研究证实，这些肽不会受到蛋白水解降解。这些肽与一种来源于细菌的佐剂疫苗递送系统和壳聚糖一起被制成共轭尼古丁疫苗候选物，壳聚糖是一种稳定化合物。在树突状细胞系中进行了制剂测试，以确定使用 ELISA 测定哪种组合能够引起最大的 1L-1β反应。这 3 种肽能够增强细胞因子反应，超过佐剂递送系统单独诱导的反应。在 BALB/c 小鼠中的疫苗接种研究表明，作为测量指标的尼古丁特异性抗体水平，从包括肽在内的共轭疫苗结构中引起了最佳的免疫反应。同种型分析强调，该肽能够使免疫反应向体液免疫优势转变。总的来说，这些结果表明，非天然肽不仅可用于开发尼古丁疫苗，而且可用于其他成瘾物质和常规疫苗靶标，作为佐剂使用。
