Royet, J. | Search bioRxiv

bioRxiv2022

Dual mode of PGRP-LE-dependent NF-κB pathway activation in bacteria infected guts

Interactions between prokaryotes and eukaryotes require a dialogue between MAMPs and PRRs. In Drosophila, bacterial peptidoglycan is detected by PGRP receptors. While the components of the signaling cascades activated upon PGN/PGRP interactions are well characterized, little is known about the subcellular events that translate these early signaling steps into target gene transcription. Using a Drosophila enteric infection model, we show that gut-associated bacteria can induce the formation of intracellular PGRP-LE aggregates which colocalized with the early endosome marker Rab5. Combining microscopic and RNA-seq analysis, we demonstrate that RNAi inactivation of the endocytosis pathway in the Drosophila gut affects the expression of essential regulators of the NF-{kappa}B response leading not only to a disruption of the immune response locally in the gut but also at the systemic level. This work sheds new light on the involvement of the endocytosis pathway in the control of the gut response to intestinal bacterial infection Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=181 HEIGHT=200 SRC="FIGDIR/small/490610v2_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@1ed549eorg.highwire.dtl.DTLVardef@4e5315org.highwire.dtl.DTLVardef@30b1eaorg.highwire.dtl.DTLVardef@f08401_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2021

Bacteria-derived peptidoglycan triggers an NF-kB dependent response in Drosophila gustatory neurons

Probing the external world is essential for eukaryotes to distinguish beneficial from pathogenic microorganisms. If it is clear that this task falls to the immune cells, recent work shows that neurons can also detect microbes, although the molecules and mechanisms involved are less characterized. In Drosophila, detection of bacteria-derived peptidoglycan by pattern recognition receptor (PRR) of the PGRP family expressed in immune cells, triggers NF-{kappa}B/IMD dependent signaling. We show here that one PGRP protein, called PGRP-LB, is expressed in some probosciss bitter taste neurons. In vivo calcium imaging reveals that the PGRP/IMD pathway is cell-autonomously required in these neurons to transduce the PGN signal. We finally show that NF-{kappa}B/IMD pathway activation in bitter neurons influences fly behavior. This demonstrates that flies use the same bacterial elicitor and signaling module to sense bacterial presence via the peripheral nervous system and trigger an anti-bacterial response in immune-competent cells.

neuroscience↗