[en] Bacterial outer membrane vesicles (OMVs), as well as OMV-associated small RNAs, have been demonstrated to play a role in host–pathogen interactions. The presence of larger RNA transcripts in OMVs has been less studied and their potential role in host–pathogen interactions remains largely unknown. Here we analyze RNA from OMVs secreted by Salmonella enterica serovar Typhimurium (S. Typhimurium) cultured under different conditions, which mimic host–pathogen interactions. S. Typhimurium was grown to exponential and stationary growth phases in minimal growth control medium (phosphate-carbon-nitrogen, PCN), as well as in acidic and phosphate-depleted PCN, comparable to the macrophage environment and inducing therefore the expression of Salmonella pathogenicity island 2 (SPI-2) genes. Moreover, Salmonella pathogenicity island 1 (SPI-1), which is required for virulence during the intestinal phase of infection, was induced by culturing S. Typhimurium to the stationary phase in Lysogeny Broth (LB). For each condition, we identified OMV-associated RNAs that are enriched in the extracellular environment relative to the intracellular space. All RNA classes could be observed, but a vast majority of rRNA was exported in all conditions in variable proportions with a notable decrease in LB SPI-1 inducing media. Several mRNAs and ncRNAs were specifically enriched in/on OMVs dependent on the growth conditions. Important to note is that some RNAs showed identical read coverage profiles intracellularly and extracellularly, whereas distinct coverage patterns were observed for other transcripts, suggesting a specific processing or degradation. Moreover, PCR experiments confirmed that distinct RNAs were present in or on OMVs as full-length transcripts (IsrB-1/2; IsrA; ffs; SsrS; CsrC; pSLT035; 10Sa; rnpB; STM0277; sseB; STM0972; STM2606), whereas others seemed to be rather present in a processed or degraded form. Finally, we show by a digestion protection assay that OMVs are able to prevent enzymatic degradation of given full-length transcripts (SsrS, CsrC, 10Sa, and rnpB). In summary, we show that OMV-associated RNA is clearly different in distinct culture conditions and that at least a fraction of the extracellular RNA is associated as a full-length transcripts with OMVs, indicating that some RNAs are protected by OMVs and thereby leaving open the possibility that those might be functionally active.
Research center :
- Luxembourg Centre for Systems Biomedicine (LCSB): Eco-Systems Biology (Wilmes Group) - Luxembourg Centre for Systems Biomedicine (LCSB): Bioinformatics Core (R. Schneider Group) ULHPC - University of Luxembourg: High Performance Computing
Disciplines :
Microbiology Environmental sciences & ecology
Author, co-author :
Malabirade, Antoine ; University of Luxembourg > Luxembourg Centre for Systems Biomedicine (LCSB)
Habier, Janine ; University of Luxembourg > Luxembourg Centre for Systems Biomedicine (LCSB)
Heintz-Buschart, Anna
May, Patrick ; University of Luxembourg > Luxembourg Centre for Systems Biomedicine (LCSB)
Godet, Julien
Halder, Rashi ; University of Luxembourg > Luxembourg Centre for Systems Biomedicine (LCSB)
Etheridge, Alton
Galas, David
Wilmes, Paul ; University of Luxembourg > Luxembourg Centre for Systems Biomedicine (LCSB)
Fritz, Joëlle ; University of Luxembourg > Luxembourg Centre for Systems Biomedicine (LCSB)
External co-authors :
yes
Language :
English
Title :
The RNA Complement of Outer Membrane Vesicles From Salmonella enterica Serovar Typhimurium Under Distinct Culture Conditions
FNR8066232 - Host-microbes Interactions Via Bacterial Extracellular Small Rnas, 2014 (01/04/2015-31/08/2017) - Joelle Fritz
Name of the research project :
BeAR
Funders :
FNR - Fonds National de la Recherche [LU] French Infrastructure for Integrated Structural Biology FRISBI ANR-10-INBS-05 Instruct-ERIC FNR CORE/15/BM/10404093 FNR CORE/16/BM/11276306 NIH Common Fund Extracellular RNA Communication Consortium (1U01HL126496), Baylor subaward (5U54DA036134)