Supplementary Material for: Functional Interaction between Apolipophorins and Complement Regulate the Mosquito Immune Response to Systemic Infections

2016-10-14T11:50:32Z (GMT) by Kamareddine L. Nakhleh J. Osta M.A.
<br>The complement-like protein thioester-containing protein 1 (TEP1) is the hallmark effector molecule against <i>Plasmodium</i> ookinetes in the malaria vector <i>Anopheles gambiae</i>. We have previously shown that the knockdown of the noncatalytic clip domain serine protease CLIPA2 increased TEP1-mediated killing rendering mosquitoes more resistant to <i>Plasmodium</i>, bacterial and fungal infections. Here, CLIPA2 coimmunoprecipitation from the hemolymph of <i>Beauveria bassiana</i>-infected mosquitoes followed by mass spectrometry and functional genetic analysis led to the identification of the <i>Apolipophorin-II/I</i> gene, encoding the two lipid carrier proteins Apo-I and II, as a novel negative regulator of TEP1-mediated immune response during mosquito systemic infections. <i>Apo-II/I</i> exhibits a similar RNAi phenotype as <i>CLIPA2</i> in mosquito bioassays characterized by increased resistance to <i>B. bassiana</i> and <i>Escherichia coli</i> infections. We provide evidence that this enhanced resistance to systemic infections is TEP1 dependent. Interestingly, silencing <i>Apo-II/I</i> but not <i>CLIPA2 </i>upregulated the expression of <i>TEP1</i> following systemic infections with <i>E. coli</i> and <i>B. bassiana</i> in a c-Jun N-terminal kinase pathway-dependent manner. Our results suggest that mosquito Apo-II/I plays an important immune regulatory role during systemic infections and provide novel insight into the functional interplay between lipid metabolism and immune gene regulation.