Supplementary Material for: Thioester-Containing Protein-4 Regulates the Drosophila Immune Signaling and Function against the Pathogen Photorhabdus

2016-10-21T10:12:19Z (GMT) by Shokal U. Eleftherianos I.
<br>Despite important progress in identifying the molecules that participate in the immune response of <i>Drosophila melanogaster</i> to microbial infections, the involvement of thioester-containing proteins (TEPs) in the antibacterial immunity of the fly is not fully clarified. Previous studies mostly focused on identifying the function of TEP2, TEP3 and TEP6 molecules in the <i>D. melanogaster</i> immune system. Here, we investigated the role of TEP4 in the regulation and function of <i>D. melanogaster</i> host defense against 2 virulent pathogens from the genus <i>Photorhabdus</i>, i.e. the insect pathogenic bacterium <i>Photorhabdus luminescens</i> and the emerging human pathogen <i>P. asymbiotica</i>. We demonstrate that <i>Tep4</i> is strongly upregulated in adult flies following the injection of <i>Photorhabdus</i> bacteria. We also show that <i>Tep4</i> loss-of-function mutants are resistant to <i>P. luminescens </i>but not to <i>P. asymbiotica</i> infection<i>.</i> In addition, we find that inactivation of <i>Tep4 </i>results in the upregulation of the Toll and Imd immune pathways, and the downregulation of the Jak/Stat and Jnk pathways upon <i>Photorhabdus</i> infection. We document that loss of <i>Tep4</i> promotes melanization and phenoloxidase activity in the mutant flies infected with <i>Photorhabdus</i>. Together, these findings generate novel insights into the immune role of TEP4 as a regulator and effector of the <i>D. melanogaster</i> antibacterial immune response.