Michelini Zuleika, Negri Donatella R M, Baroncelli Silvia, Spada Massimo, Leone Pasqualina, Bona Roberta, Klotman Mary E, Cara Andrea
Department of Therapeutic Research and Medicines Evaluation, Istituto Superiore di Sanità, Rome, Italy.
Vaccine. 2009 Jul 23;27(34):4622-9. doi: 10.1016/j.vaccine.2009.05.070. Epub 2009 Jun 11.
Integrase (IN) defective lentiviral vectors have a high safety profile and might prove useful as immunizing agents especially against HIV-1. However, IN defective SIV-based vectors must be developed in order to test their potential in the non-human primate models (NHP) of AIDS. To this aim we tested a novel SIV-based IN defective lentiviral vector for its ability to induce sustained immune responses in mice. BALB/c mice were immunized once intramuscularly with a SIV-based IN defective lentiviral vector expressing the model antigen enhanced green fluorescence protein (eGFP). Immune responses were evaluated 90 days after the injection and compared with those elicited with the IN competent counterpart. The IN defective vector was able to efficiently elicit specific and long-lasting polyfunctional immune responses as evaluated by enzyme-linked immunospot (ELISPOT) assays for interferon-gamma (IFN-gamma) in spleens, bone marrow (BM) and draining lymph nodes, and by intracellular staining (ICS) for IFN-gamma, Interleukin-2 (IL-2) and tumor necrosis factor (TNF-alpha) in both splenocytes and BM cells without integration of the vector into the host genome. This is the first demonstration that an IN defective SIV-based lentiviral vector provides effective immunization, thus paving the way for the construction of IN defective vectors expressing SIV antigen(s) and test their efficacy against a SIV virus challenge in the NHP model of AIDS.
整合酶（IN）缺陷型慢病毒载体具有很高的安全性，可能作为免疫制剂很有用，特别是针对HIV-1。然而，必须开发基于IN缺陷型的猴免疫缺陷病毒（SIV）载体，以便在艾滋病非人灵长类动物模型（NHP）中测试其潜力。为此，我们测试了一种新型的基于SIV的IN缺陷型慢病毒载体在小鼠中诱导持续免疫反应的能力。用表达模型抗原增强型绿色荧光蛋白（eGFP）的基于SIV的IN缺陷型慢病毒载体对BALB/c小鼠进行一次肌肉内免疫。在注射后90天评估免疫反应，并与由具有整合酶功能的对应载体引发的免疫反应进行比较。通过对脾脏、骨髓（BM）和引流淋巴结中的干扰素-γ（IFN-γ）进行酶联免疫斑点（ELISPOT）分析，以及对脾细胞和BM细胞中的IFN-γ、白细胞介素-2（IL-2）和肿瘤坏死因子（TNF-α）进行细胞内染色（ICS）评估，发现该IN缺陷型载体能够有效地引发特异性和持久的多功能免疫反应，且载体未整合到宿主基因组中。这是首次证明基于IN缺陷型的SIV慢病毒载体可提供有效的免疫接种，从而为构建表达SIV抗原的IN缺陷型载体并在艾滋病NHP模型中测试其对SIV病毒攻击的疗效铺平了道路。
