AUTHOR=Wan Bin , Goguet Emilie , Ravallec Marc , Pierre Olivier , Lemauf Séverine , Volkoff Anne-Nathalie , Gatti Jean-Luc , Poirié Marylène 

TITLE=Venom Atypical Extracellular Vesicles as Interspecies Vehicles of Virulence Factors Involved in Host Specificity: The Case of a Drosophila Parasitoid Wasp

JOURNAL=Frontiers in Immunology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2019.01688

DOI=10.3389/fimmu.2019.01688

ISSN=1664-3224

ABSTRACT=<p>Endoparasitoid wasps, which lay eggs inside the bodies of other insects, use various strategies to protect their offspring from the host immune response. The hymenopteran species of the genus <italic>Leptopilina</italic>, parasites of <italic>Drosophila</italic>, rely on the injection of a venom which contains proteins and peculiar vesicles (hereafter venosomes). We show here that the injection of purified <italic>L. boulardi</italic> venosomes is sufficient to impair the function of the <italic>Drosophila melanogaster</italic> lamellocytes, a hemocyte type specialized in the defense against wasp eggs, and thus the parasitic success of the wasp. These venosomes seem to have a unique extracellular biogenesis in the wasp venom apparatus where they acquire specific secreted proteins/virulence factors and act as a transport system to deliver these compounds into host lamellocytes. The level of venosomes entry into lamellocytes of different <italic>Drosophila</italic> species was correlated with the rate of parasitism success of the wasp, suggesting that this venosome-cell interaction may represent a new evolutionary level of host-parasitoid specificity.</p>