Discovery and characterization of two Nimrod superfamily members in Anopheles gambiae. (December 2013)

• Record Type: Journal Article
• Authors: Midega, Janet; Blight, Joshua; Lombardo, Fabrizio; Povelones, Michael; Kafatos, Fotis; Christophides, George K.
• Is Part Of: Pathogens and global health. Volume 107:Number 8(2013)
• Page Start: 463
• Page End: 474
• Publication Date: 2013-12
• Subjects: Communicable diseases -- Periodicals; Public health -- International cooperation -- Periodicals; World health -- Periodicals; 362.1969
• DOI: 10.1179/204777213X13867543472674
• Languages: English
• ISSNs: 2047-7724

Abstract

<abstract> <title> <x content-type="archive" xml:space="preserve">Abstract</x> </title> <sec> <p>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 <italic>Anopheles gambiae</italic> Nimrod superfamily, namely AgNimB2 and AgEater. We confirm that current annotation of the <italic>An</italic>. <italic>gambiae</italic> genome incorrectly identifies AgNimB2 and AgEater as a single gene, AGAP009762. Through <italic>in silico</italic> and experimental approaches, it has been shown that AgNimB2 is a secreted protein that mediates phagocytosis of <italic>Staphylococcus aureus</italic> but not of <italic>Escherichia coli</italic> bacteria. We also reveal that this function does not involve a direct interaction of AgNimB2 with <italic>S. aureus</italic>. 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-<italic>Plasmodium</italic> effect. Conversely, AgEater is a membrane-bound protein that either functions redundantly or is dispensable for phagocytosis of <italic>E. coli</italic> or <italic>S. aureus</italic>. Our study provides insights into the role of members of the complex Nimrod superfamily in <italic>An. gambiae</italic>, the most important African vector of human malaria.</p> </sec> </abstract>