Pathog Glob Health. 2013 Dec;107(8):463-74. doi: 10.1179/204777213X13867543472674.
Anti-bacterial proteins in mosquitoes are known to play an important modulatory role on immune responses to infections with human pathogens including malaria parasites. In this study we characterized two members of the Anopheles gambiae Nimrod superfamily, namely AgNimB2 and AgEater. We confirm that current annotation of the An. gambiae genome incorrectly identifies AgNimB2 and AgEater as a single gene, AGAP009762. Through in silico and experimental approaches, it has been shown that AgNimB2 is a secreted protein that mediates phagocytosis of Staphylococcus aureus but not of Escherichia coli bacteria. We also reveal that this function does not involve a direct interaction of AgNimB2 with S. aureus. Therefore, AgNimB2 may act downstream of complement-like pathway activation, first requiring bacterial opsonization. In addition, it has been shown that AgNimB2 has an anti-Plasmodium effect. Conversely, AgEater is a membrane-bound protein that either functions redundantly or is dispensable for phagocytosis of E. coli or S. aureus. Our study provides insights into the role of members of the complex Nimrod superfamily in An. gambiae, the most important African vector of human malaria.
蚊子中的抗菌蛋白已知在调节对人类病原体（包括疟原虫）感染的免疫反应方面发挥着重要作用。在这项研究中，我们对两种冈比亚按蚊 Nimrod 超家族成员进行了研究，即 AgNimB2 和 AgEater。我们证实，目前对冈比亚按蚊基因组的注释错误地将 AgNimB2 和 AgEater 鉴定为一个单一基因 AGAP009762。通过计算机模拟和实验方法，已经表明 AgNimB2 是一种分泌蛋白，可介导金黄色葡萄球菌但不能介导大肠杆菌的吞噬作用。我们还揭示了该功能不涉及 AgNimB2 与金黄色葡萄球菌的直接相互作用。因此，AgNimB2 可能在补体样途径激活的下游起作用，首先需要细菌调理。此外，已经表明 AgNimB2 具有抗疟原虫作用。相反，AgEater 是一种膜结合蛋白，对于大肠杆菌或金黄色葡萄球菌的吞噬作用来说，它要么是冗余的，要么是可有可无的。我们的研究提供了对复杂 Nimrod 超家族成员在非洲最重要的人类疟疾传播媒介冈比亚按蚊中的作用的深入了解。
