AUTHOR=Sharmin Zinat , Samarah Hani , Aldaya Bourricaudy Rafael , Ochoa Laura , Serbus Laura Renee 

TITLE=Cross-validation of chemical and genetic disruption approaches to inform host cellular effects on Wolbachia abundance in Drosophila

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1364009

DOI=10.3389/fmicb.2024.1364009

ISSN=1664-302X

ABSTRACT=<sec><title>Introduction</title><p>Endosymbiotic <italic>Wolbachia</italic> bacteria are widespread in nature, present in half of all insect species. The success of <italic>Wolbachia</italic> is supported by a commensal lifestyle. Unlike bacterial pathogens that overreplicate and harm host cells, <italic>Wolbachia</italic> infections have a relatively innocuous intracellular lifestyle. This raises important questions about how <italic>Wolbachia</italic> infection is regulated. Little is known about how <italic>Wolbachia</italic> abundance is controlled at an organismal scale.</p></sec><sec><title>Methods</title><p>This study demonstrates methodology for rigorous identification of cellular processes that affect whole-body <italic>Wolbachia</italic> abundance, as indicated by absolute counts of the <italic>Wolbachia surface protein</italic> (<italic>wsp</italic>) gene.</p></sec><sec><title>Results</title><p>Candidate pathways, associated with well-described infection scenarios, were identified. <italic>Wolbachia</italic>-infected fruit flies were exposed to small molecule inhibitors known for targeting those same pathways. Sequential tests in <italic>D. melanogaster</italic> and <italic>D. simulans</italic> yielded a subset of chemical inhibitors that significantly affected whole-body <italic>Wolbachia</italic> abundance, including the Wnt pathway disruptor, IWR-1 and the mTOR pathway inhibitor, Rapamycin. The implicated pathways were genetically retested for effects in <italic>D. melanogaster</italic>, using inducible RNAi expression driven by constitutive as well as chemically-induced somatic GAL4 expression. Genetic disruptions of <italic>armadillo</italic>, <italic>tor,</italic> and <italic>ATG6</italic> significantly affected whole-body <italic>Wolbachia</italic> abundance.</p></sec><sec><title>Discussion</title><p>As such, the data corroborate reagent targeting and pathway relevance to whole-body <italic>Wolbachia</italic> infection. The results also implicate Wnt and mTOR regulation of autophagy as important for regulation of <italic>Wolbachia</italic> titer.</p></sec>