Inducing Humoral and Cellular Responses to Multiple Sporozoite and Liver-Stage Malaria Antigens Using Exogenous Plasmid DNA
Inducing Humoral and Cellular Responses to Multiple Sporozoite and Liver-Stage Malaria Antigens Using Exogenous Plasmid DNA
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DOI：
10.1128/iai.00180-13
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发表时间：
2013-10-01
影响因子：
3.1
通讯作者：
Weiner, D. B.
中科院分区：
文献类型：
--
作者：
Ferraro, B.;Talbott, K. T.;Weiner, D. B.
增强对多种子孢子和肝脏阶段抗原的体液和细胞应答的候选疫苗可能能够提供针对恶性疟原虫疟疾的保护;然而，用于配制和递送这样的疫苗的技术仍然难以捉摸。在这里，我们报告了一种优化的DNA疫苗方法的临床前评估，该方法针对四种恶性疟原虫抗原：环子孢子蛋白（CSP），肝阶段抗原1（LSA 1），血小板反应蛋白相关的匿名蛋白（TRAP），以及动合子和子孢子的细胞穿越蛋白（CelTOS）。为每种抗原设计合成DNA序列，并进行修饰以改善表达，并使用体内电穿孔（EP）递送。在小鼠和非人灵长类动物（NHP）中评价了免疫原性，并通过酶联免疫吸附试验（ELISA）、γ干扰素（IFN-γ）酶联免疫吸附斑点（ELISpot）试验和流式细胞术进行了评估。在小鼠中，具有EP递送的DNA诱导抗原特异性IFN-γ产生，如通过ELISpot测定和针对所有抗原的IgG血清转化所测量的。IFN-γ、白细胞介素-2和肿瘤坏死因子α的持续产生在CD 4（+）和CD 8（+）T细胞区室中被引发。此外，肝CD 8（+）淋巴细胞产生LSA 1特异性IFN-γ。通过这种方法赋予小鼠的免疫应答转化为NHP模型，其通过ELISpot测定和细胞内细胞因子染色显示细胞应答。值得注意的是，在NHP中观察到抗原特异性CD 8（+）颗粒酶B+ T细胞。总的来说，这些数据表明，通过编码疟疾寄生虫抗原的DNA/EP递送基因序列在动物模型中具有免疫原性，并且可以利用免疫系统的体液和细胞臂。
A vaccine candidate that elicits humoral and cellular responses to multiple sporozoite and liver-stage antigens may be able to confer protection against Plasmodium falciparum malaria; however, a technology for formulating and delivering such a vaccine has remained elusive. Here, we report the preclinical assessment of an optimized DNA vaccine approach that targets four P. falciparum antigens: circumsporozoite protein (CSP), liver stage antigen 1 (LSA1), thrombospondin-related anonymous protein (TRAP), and cell-traversal protein for ookinetes and sporozoites (CelTOS). Synthetic DNA sequences were designed for each antigen with modifications to improve expression and were delivered using in vivo electroporation (EP). Immunogenicity was evaluated in mice and nonhuman primates (NHPs) and assessed by enzyme-linked immunosorbent assay (ELISA), gamma interferon (IFN-gamma) enzyme-linked immunosorbent spot (ELISpot) assay, and flow cytometry. In mice, DNA with EP delivery induced antigen-specific IFN-gamma production, as measured by ELISpot assay and IgG seroconversion against all antigens. Sustained production of IFN-gamma, interleukin-2, and tumor necrosis factor alpha was elicited in both the CD4(+) and CD8(+) T cell compartments. Furthermore, hepatic CD8(+) lymphocytes produced LSA1-specific IFN-gamma. The immune responses conferred to mice by this approach translated to the NHP model, which showed cellular responses by ELISpot assay and intracellular cytokine staining. Notably, antigen-specific CD8(+) granzyme B+ T cells were observed in NHPs. Collectively, the data demonstrate that delivery of gene sequences by DNA/EP encoding malaria parasite antigens is immunogenic in animal models and can harness both the humoral and cellular arms of the immune system.