2012年8月17日 讯 /生物谷BIOON/ --尽管疟疾和HIV都是世界性大流行疾病，而且同时感染这两种疾病能够导致比较高的死亡率，但是科学家们对HIV-1和导致疟疾的恶性疟原虫(Plasmodium falciparum)之间的相互作用仍然知之甚少。然而，根据一篇刊登在Journal of Visualized Experiments(JoVE)期刊上的视频论文，研究人员描述了一种新技术来在体外培养的人细胞中研究HIV-1和恶性疟原虫之间的相互作用，以便允许科学家们研究这两种微生物共同感染宿主细胞的不同参数。
领导这项研究的David Richard博士解释道，“被HIV-1感染的免疫细胞遭遇这种疟原虫时会发生什么，我们还不太了解。来自几项探究这两种疾病相互作用的研究结果有时是相互冲突的。我们希望我们的方法将允许我们在一个简化的系统中充分地研究这些相互作用。”
在这两种疾病中，每种疾病都攻击人血液中不同的组分，因而破坏正常的免疫功能。恶性疟原虫感染红细胞导致病人发热、颤抖、呕吐或惊厥。HIV-1通过感染包括巨噬细胞和辅助性T细胞在内的免疫系统组分，然后进行自我复制和破坏宿主细胞，从而导致病人患上获得性免疫缺陷综合症(acquired immune deficiency syndrome, AIDS)。通过在体外研究每种疾病不同阶段的共同感染情形，科学家们能够更好地理解疟疾感染和HIV复制的不同阶段如何影响另一种疾病的发生和严重性。为此，Richard博士和他的实验室呈现一种技术来研究被恶性疟原虫感染的红细胞如何影响HIV-1在单核细胞源性巨噬细胞(monocyte-derived macrophage)中的复制。
Richard博士指出，“通过这篇发表在JoVE期刊上的论文，人们能够在实验中观察到发生什么。这项视频展示有助于简单地理解一段较长的实验程序和在细胞水平上更加充分地描绘出这些相互作用的图谱。”他希望这篇论文的发表将让科学界能够在细胞水平上研究这些相互作用，这将是改善感染上这些疾病的个人的生活质量的第一步。JoVE期刊编辑Charlotte Frank Sage博士陈述道，“这种实验程序提供一种工具来研究恶性疟原虫和HIV之间的相互作用。JoVE期刊发表的这种实验程序将允许全世界的科学家们能够详细地验证这种系统，从而有助于将这种技术应用到他们的实验室之中。” (生物谷Bioon.com)
本文编译自Novel technique demonstrates interactions between malaria parasite and HIV
doi: 10.3791/4166
PMC:
PMID:
An In vitro Co-infection Model to Study Plasmodium falciparum-HIV-1 Interactions in Human Primary Monocyte-derived Immune Cells
Guadalupe Andreani, Dominic Gagnon, Robert Lodge, Michel J. Tremblay, Dave Richard
Plasmodium falciparum, the causative agent of the deadliest form of malaria, and human immunodeficiency virus type-1 (HIV-1) are among the most important health problems worldwide, being responsible for a total of 4 million deaths annually1. Due to their extensive overlap in developing regions, especially Sub-Saharan Africa, co-infections with malaria and HIV-1 are common, but the interplay between the two diseases is poorly understood. Epidemiological reports have suggested that malarial infection transiently enhances HIV-1 replication and increases HIV-1 viral load in co-infected individuals2,3. Because this viremia stays high for several weeks after treatment with antimalarials, this phenomenon could have an impact on disease progression and transmission.
The cellular immunological mechanisms behind these observations have been studied only scarcely. The few in vitro studies investigating the impact of malaria on HIV -1 have demonstrated that exposure to soluble malarial antigens can increase HIV-1 infection and reactivation in immune cells. However, these studies used whole cell extracts of P. falciparum schizont stage parasites and peripheral blood mononuclear cells (PBMC), making it hard to decipher which malarial component(s) was responsible for the observed effects and what the target host cells were4,5. Recent work has demonstrated that exposure of immature monocyte-derived dendritic cells to the malarial pigment hemozoin increased their ability to transfer HIV-1 to CD4+ T cells6,7, but that it decreased HIV-1 infection of macrophages8. To shed light on this complex process, a systematic analysis of the interactions between the malaria parasite and HIV-1 in different relevant human primary cell populations is critically needed.
Several techniques for investigating the impact of HIV-1 on the phagocytosis of micro-organisms and the effect of such pathogens on HIV-1 replication have been described. We here present a method to investigate the effects of P. falciparum-infected erythrocytes on the replication of HIV-1 in human primary monocyte-derived macrophages. The impact of parasite exposure on HIV-1 transcriptional/translational events is monitored by using single cycle pseudotyped viruses in which a luciferase reporter gene has replaced the Env gene while the effect on the quantity of virus released by the infected macrophages is determined by measuring the HIV-1 capsid protein p24 by ELISA in cell supernatants.
