Heterologous prime-boost-boost immunisation of Chinese cynomolgus macaques using DNA and recombinant poxvirus vectors expressing HIV-1 virus-like particles.
Heterologous prime-boost-boost immunisation of Chinese cynomolgus macaques using DNA and recombinant poxvirus vectors expressing HIV-1 virus-like particles.
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DOI：
10.1186/1743-422x-8-429
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发表时间：
2011-09-07
期刊：
影响因子：
4.8
通讯作者：
Blanchard TJ
中科院分区：
文献类型：
--
作者：
Bridge SH;Sharpe SA;Dennis MJ;Dowall SD;Getty B;Anson DS;Skinner MA;Stewart JP;Blanchard TJ
由于在最近的泰国安慰剂对照试验中观察到重复使用gp120增强的重组金丝雀痘疫苗的保护效果，人们对基于痘病毒载体的HIV疫苗的开发重新产生了兴趣。这项研究试图调查中国食蟹猴的异种Prime-Boost-Boost疫苗方案，包括DNA疫苗和表达HIV病毒样颗粒的重组痘病毒载体，该病毒颗粒携带来自撒哈拉以南非洲最流行的分支的囊膜，是否集中了对共享中和表位的抗体反应。对3只食蟹猴进行肌肉注射免疫，免疫方案为：先用两种表达A、B亚基Gag的DNA疫苗，然后用表达HIV-1 D亚基Gag、Env和霍乱毒素B亚单位的重组鸡痘病毒加强免疫，最后用表达HIV-1 C亚基、Gag和人类补体蛋白C3d的重组改良痘苗病毒Ankara加强免疫。我们用ELISA检测猕猴血清抗体反应，用干扰素-γELISpot计数T细胞反应，用TZM-blβ-半乳糖苷酶试验评估HIV-1的血清中和作用。本研究表明，大而复杂的合成DNA序列可以一步成功地克隆到两个痘病毒载体：MVA和FPV中，并且重组痘病毒可以培养成高滴度。候选疫苗显示出适当的重组蛋白表达，并在透射电子显微镜下看到真正的HIV病毒样颗粒的形成。此外，共聚焦免疫荧光显微镜显示，候选疫苗具有共同的B12表位。候选疫苗被安全地接种到中国食蟹猴身上，这些猕猴在研究结束时产生了适度的T细胞反应，但三只猕猴中只有一只引起了HIV特异性抗体反应。然而，使用TZM-b1β半乳糖苷酶试验，这些抗体并不能中和艾滋病毒-1或V3敏感株SF162的初级分离株。MVA和FP9是理想的HIV-1疫苗复制缺陷病毒载体，因为它们在人类身上使用时具有良好的安全性。这项研究表明，这种新的Prime-Boost-Boost方案对中国食蟹猴的免疫原性较差。
There is renewed interest in the development of poxvirus vector-based HIV vaccines due to the protective effect observed with repeated recombinant canarypox priming with gp120 boosting in the recent Thai placebo-controlled trial. This study sought to investigate whether a heterologous prime-boost-boost vaccine regimen in Chinese cynomolgus macaques with a DNA vaccine and recombinant poxviral vectors expressing HIV virus-like particles bearing envelopes derived from the most prevalent clades circulating in sub-Saharan Africa, focused the antibody response to shared neutralising epitopes. Three Chinese cynomolgus macaques were immunised via intramuscular injections using a regimen composed of a prime with two DNA vaccines expressing clade A Env/clade B Gag followed by boosting with recombinant fowlpox virus expressing HIV-1 clade D Gag, Env and cholera toxin B subunit followed by the final boost with recombinant modified vaccinia virus Ankara expressing HIV-1 clade C Env, Gag and human complement protein C3d. We measured the macaque serum antibody responses by ELISA, enumerated T cell responses by IFN-γ ELISpot and assessed seroneutralisation of HIV-1 using the TZM-bl β-galactosidase assay with primary isolates of HIV-1. This study shows that large and complex synthetic DNA sequences can be successfully cloned in a single step into two poxvirus vectors: MVA and FPV and the recombinant poxviruses could be grown to high titres. The vaccine candidates showed appropriate expression of recombinant proteins with the formation of authentic HIV virus-like particles seen on transmission electron microscopy. In addition the b12 epitope was shown to be held in common by the vaccine candidates using confocal immunofluorescent microscopy. The vaccine candidates were safely administered to Chinese cynomolgus macaques which elicited modest T cell responses at the end of the study but only one out of the three macaques elicited an HIV-specific antibody response. However, the antibodies did not neutralise primary isolates of HIV-1 or the V3-sensitive isolate SF162 using the TZM-bl β-galactosidase assay. MVA and FP9 are ideal replication-deficient viral vectors for HIV-1 vaccines due to their excellent safety profile for use in humans. This study shows this novel prime-boost-boost regimen was poorly immunogenic in Chinese cynomolgus macaques.