Institute of Medical Microbiology and Hygiene, University of Regensburg, Regensburg, Germany.
Biodesign Institute, Arizona State University, Tempe, Arizona, USA.
J Virol. 2019 Jan 17;93(3). doi: 10.1128/JVI.01529-18. Print 2019 Feb 1.
The use of heterologous immunization regimens and improved vector systems has led to increases in immunogenicity of HIV-1 vaccine candidates in nonhuman primates. In order to resolve interrelations between different delivery modalities, three different poxvirus boost regimens were compared. Three groups of rhesus macaques were each primed with the same DNA vaccine encoding Gag, Pol, Nef, and gp140. The groups were then boosted with either the vaccinia virus strain NYVAC or a variant with improved replication competence in human cells, termed NYVAC-KC. The latter was administered either by scarification or intramuscularly. Finally, macaques were boosted with adjuvanted gp120 protein to enhance humoral responses. The regimen elicited very potent CD4 and CD8 T cell responses in a well-balanced manner, peaking 2 weeks after the boost. T cells were broadly reactive and polyfunctional. All animals exhibited antigen-specific humoral responses already after the poxvirus boost, which further increased following protein administration. Polyclonal reactivity of IgG antibodies was highest against HIV-1 clade C Env proteins, with considerable cross-reactivity to other clades. Substantial effector functional activities (antibody-dependent cell-mediated cytotoxicity and antibody-dependent cell-mediated virus inhibition) were observed in serum obtained after the last protein boost. Notably, major differences between the groups were absent, indicating that the potent priming induced by the DNA vaccine initially framed the immune responses in such a way that the subsequent boosts with NYVAC and protein led only to an increase in the response magnitudes without skewing the quality. This study highlights the importance of selecting the best combination of vector systems in heterologous prime-boost vaccination regimens. The evaluation of HIV vaccine efficacy trials indicates that protection would most likely correlate with a polyfunctional immune response involving several effector functions from all arms of the immune system. Heterologous prime-boost regimens have been shown to elicit vigorous T cell and antibody responses in nonhuman primates that, however, qualitatively and quantitatively differ depending on the respective vector systems used. The present study evaluated a DNA prime and poxvirus and protein boost regimen and compared how two poxvirus vectors with various degrees of replication capacity and two different delivery modalities-conventional intramuscular delivery and percutaneous delivery by scarification-impact several immune effectors. It was found that despite the different poxvirus boosts, the overall immune responses in the three groups were similar, suggesting the potent DNA priming as the major determining factor of immune responses. These findings emphasize the importance of selecting optimal priming agents in heterologous prime-boost vaccination settings.
使用异源免疫方案和改良的载体系统已导致 HIV-1 疫苗候选物在非人类灵长类动物中的免疫原性增加。为了解决不同传递方式之间的相互关系,比较了三种不同的痘苗病毒增强方案。三组恒河猴均用相同的 DNA 疫苗进行初次免疫,该疫苗编码 Gag、Pol、Nef 和 gp140。然后,将三组恒河猴用牛痘病毒株 NYVAC 或在人细胞中复制能力增强的变体 NYVAC-KC 进行增强。后者通过划痕或肌肉内给药。最后,用佐剂 gp120 蛋白增强灵长类动物的体液反应。该方案在增强后 2 周内引发了非常有效的 CD4 和 CD8 T 细胞反应,平衡良好。T 细胞反应广泛且多功能。所有动物在痘苗病毒增强后已经表现出抗原特异性体液反应,在给予蛋白后进一步增加。多克隆 IgG 抗体反应性最高针对 HIV-1 谱系 C Env 蛋白,对其他谱系有相当大的交叉反应性。在最后一次蛋白增强后获得的血清中观察到大量效应功能活性(抗体依赖性细胞介导的细胞毒性和抗体依赖性细胞介导的病毒抑制)。值得注意的是,各组之间没有明显差异,表明 DNA 疫苗诱导的强烈初始免疫以这种方式构成了免疫反应,使得随后用 NYVAC 和蛋白进行的增强仅增加了反应幅度,而没有改变质量。这项研究强调了在异源初免-加强免疫接种方案中选择最佳载体系统组合的重要性。对 HIV 疫苗功效试验的评估表明,保护很可能与涉及免疫系统所有分支的几种效应功能的多功能免疫反应相关。异源初免-加强方案已在非人类灵长类动物中引发强烈的 T 细胞和抗体反应,但根据使用的不同载体系统,其质量和数量存在差异。本研究评估了 DNA 初免和痘苗病毒和蛋白加强方案,并比较了两种具有不同复制能力的痘苗病毒载体和两种不同的传递方式(常规肌肉内传递和划痕的经皮传递)如何影响几种免疫效应物。结果发现,尽管有不同的痘苗增强,但三组的总体免疫反应相似,表明强大的 DNA 初免是免疫反应的主要决定因素。这些发现强调了在异源初免-加强疫苗接种方案中选择最佳初免剂的重要性。
Viruses. 2023-8-15
Vaccines (Basel). 2020-9-8
Nature. 2017-3-23
Immunol Rev. 2017-1
Immunol Rev. 2017-1
Front Microbiol. 2016-11-2
Curr Opin HIV AIDS. 2016-11