EASL2012:IN VIVO ELECTROPORATION SIGNIFICANTLY IMPROVES THERAPEUTIC POTENCY OF A

StephenW

IN VIVO ELECTROPORATION SIGNIFICANTLY IMPROVES THERAPEUTIC POTENCY OF A DNA VACCINE TARGETING HEPADNAVIRAL PROTEINS
Speaker:Ghada Khawaja
Author:
G. Khawaja1*, T. Buronfosse2, S. Guerret3, F. Zoulim1, A. Luxembourg4, D. Hannaman4, C.F. Evans4, D. Hartmann5, L. Cova6 Affiliation:
1Immunology, Microenvironnement, Virology, INSERM U 1052, 2VetAgro-Sup, Marcy l'Etoile, 3Novotec, Lyon, France, 4ICHOR Medical Systems, San Diego, CA, USA, 5ISPB, Faculty of Pharmacy, 6Immunology, Microenvironnement, Virology, Inserm U1052, Lyon, France. *[email protected]
Background and aims:
Therapeutic DNA vaccines, able of activating both defective humoral and cellular immune responses in chronic HBV carriers, have been proposed as a particularly pertinent approach for chronic hepatitis B therapy. However, their progress into the clinic have been hampered by the relatively low magnitude and inconsistent immune responses achieved by conventional DNA delivery methods in large experimental species and humans. This long-term preclinical study aimed at investigating the therapeutic benefit of electroporation (EP)-based DNA vaccine delivery in the chronic duck hepatitis B virus (DHBV) infection model. We focused on the ability of EP-based pDNA delivery to enhance viral DNA clearance, including the covalently closed circular DNA (cccDNA) and to restore antiviral immune responses.
Methods:
DHBV-carriers ducks received injections of plasmid DNA (pDNA) encoding DHBV proteins (envelope, core) and duck IFN-? delivered either by EP or standard needle injection (SI). The viremia was monitored for 10 months, thereafter viral DNA, including cccDNA, was analyzed in necropsy liver samples by qPCR. The anti-preS humoral response was followed by ELISA and the antigenic regions were identified by peptide scanning. The liver IFN-? RNA levels were quantified by qRT- PCR.
Results: EP-based pDNA delivery resulted in a significant decrease in mean viremia titers. Importantly, the levels of intrahepatic cccDNA, a transcriptional template of virus replication, were also significantly lower in the EP-treated group as compared to the SI-treated and control groups. In addition, the humoral response to DHBV preS protein in the EP- treated group was significantly higher and was able to recognize a broader range of major antigenic regions, including neutralizing epitopes, as compared to other duck groups. Moreover, the intrahepatic IFN-? RNA levels were significantly higher in all EP-treated DHBV- carriers as compared with other groups. Such DNA-EP based therapy was well tolerated with no adverse effects.
Conclusions: Taken together our data indicate that EP-based delivery of a DHBV DNA vaccine is a safe and promising strategy able to significantly enhance hepadnaviral clearance and restore immune responses. Thus, this data strongly supports the use of this approach for chronic hepatitis B therapy in humans.

StephenW

在体内电穿孔显着提高针对议长嗜肝病毒蛋白的DNA疫苗治疗效力：
ghada卡瓦贾
作者：
G。Khawaja1 * T. Buronfosse2，S. Guerret3，F. Zoulim1，A. Luxembourg4，D Hannaman4，CF evans4 D. Hartmann5，研究Cova6从属关系：
1Immunology，Microenvironnement，病毒学，INSERM的ü1052 2VetAgro燮，马西星斗，3Novotec，里昂，法国，4ICHOR医疗系统，美国加利福尼亚州圣迭戈，5ISPB，药剂，6Immunology，Microenvironnement，病毒学，INSERM U1052学院，法国里昂。 * ghada.khawaja @ inserm.fr背景和目的：治疗性DNA疫苗，能够激活在慢性乙肝病毒携带者的缺陷的体液免疫和细胞免疫反应，已经提出了特别相关的慢性乙型肝炎治疗的方法。然而，相对较低的幅度和传统的大型实验物种和人类的DNA交付方法取得不一致的免疫反应受到阻碍其进入临床进展。这种长期的临床研究，旨在探讨电穿孔的治疗效果（EP）在慢性鸭乙型肝炎病毒（DHBV）感染模型的DNA疫苗交付。我们专注于EP基于质粒DNA交付能力，以提高病毒DNA检查，包括共价闭合环状DNA（cccDNA）和恢复抗病毒免疫反应。方法：乙型肝炎病毒携带者鸭注射质粒DNA（质粒DNA）编码乙型肝炎病毒蛋白（信封，核心）和鸭干扰素？要么由EP或标准针注射（SI）的交付。血症被监测的10个月，此后病毒的DNA，包括cccDNA的，在剖检肝脏样本的qPCR分析。反的preS体液免疫反应，其次是ELISA和肽扫描识别的抗原地区。肝脏IFN-？ QRT-PCR RNA水平进行量化。结果：EP基于质粒DNA交付造成在平均血症滴度显着下降。重要的是，肝内cccDNA水平，转录病毒复制模板，水平也EP组的SI处理和控制组相比显着降低。此外，乙型肝炎病毒前S蛋白在EP组的体液免疫反应显着提高，能够识别的主要抗原区域的范围更广，包括中和表位，比其他鸭群体。此外，肝内IFN-？ RNA水平显着较高，在所有的EP-治疗乙型肝炎病毒携带者与其他群体相比。这种DNA的EP为基础的治疗耐受性良好，无不良影响。结论：我们的数据表明，EP为基础的乙型肝炎病毒DNA疫苗的交付是一个安全和有前途的战略，能够显着提高嗜肝病毒清除和恢复免疫反应。因此，这些数据强烈支持这种方法的使用在人类慢性乙型肝炎治疗。

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