Department of Chemical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada.
Clinical Sciences Division, University of Toronto, Toronto, ON, Canada.
J Control Release. 2016 Aug 28;236:22-30. doi: 10.1016/j.jconrel.2016.06.019. Epub 2016 Jun 11.
Peptide based vaccine that incorporates one or several highly conserved CD8+ T cells epitopes to induce potent cytotoxic T lymphocyte (CTL) response is desirable for some infectious diseases, such as HIV-1 (human immunodeficiency virus-1), and cancers. However, the CD8+ T cells epitope is often weakly immunogenic, and thus requires a specific adjuvant or delivery system to enhance the efficiency. Here we investigated the use of self-assembling peptide EAK16-II based platform to achieve the co-delivery of CD8+ T cells epitope and TLR7/8 agonists (R848 or R837) for augmenting DCs maturation and HIV-1 specific CTL response. HIV-1 CTL epitope SL9 was conjugated with EAK16-II to obtain SL9-EAK16-II, which further spontaneously co-assembled with R848 or R837 in aqueous solution, forming co-assembled nanofibers. Fluorescence spectra and calorimetrical titration revealed the interaction between SL9-EAK16-II assemblies and R848 or R837 via hydrogen bonding and hydrophobic interaction, with the binding affinity (dissociation constant Kd) of 0.62μM or 0.53μM, respectively. Ex vivo generated DCs from HIV-1+ patients pulsed with the SL9-EAK16-II/R848 nanofibers stimulated significantly more polyfunctional SL9 specific CTLs, compared to the DCs pulsed with SL9 alone or the mixture of SL9 and TLR agonist. Furthermore, the nanofibers elicited stronger SL9 specific CTL response in vaccinated mice. Our findings suggest the self-assembling peptide EAK16-II might be used as a new delivery system for peptide based vaccines.
基于肽的疫苗可以将一个或多个高度保守的 CD8+ T 细胞表位纳入其中,以诱导有效的细胞毒性 T 淋巴细胞(CTL)反应,这对于某些传染病(如 HIV-1(人类免疫缺陷病毒-1)和癌症)是理想的。然而,CD8+ T 细胞表位通常免疫原性较弱,因此需要特定的佐剂或递药系统来提高效率。在这里,我们研究了使用自组装肽 EAK16-II 基平台来实现 CD8+ T 细胞表位和 TLR7/8 激动剂(R848 或 R837)的共递呈,以增强 DCs 的成熟和 HIV-1 特异性 CTL 反应。将 HIV-1 CTL 表位 SL9 与 EAK16-II 缀合以获得 SL9-EAK16-II,然后该肽在水溶液中与 R848 或 R837 进一步自发共组装,形成共组装纳米纤维。荧光光谱和量热滴定显示,SL9-EAK16-II 组装体与 R848 或 R837 之间通过氢键和疏水相互作用相互作用,其结合亲和力(解离常数 Kd)分别为 0.62μM 或 0.53μM。与单独用 SL9 或 SL9 和 TLR 激动剂混合物冲击的 DCs 相比,从 HIV-1+患者体外生成的 DCs 被 SL9-EAK16-II/R848 纳米纤维冲击后,显著刺激了更多的多功能 SL9 特异性 CTL。此外,纳米纤维在接种小鼠中引发了更强的 SL9 特异性 CTL 反应。我们的研究结果表明,自组装肽 EAK16-II 可能被用作基于肽的疫苗的新递药系统。