Abstract
Autophagy is a primordial eukaryotic pathway, which provides the immune system with multiple mechanisms for the elimination of invading pathogens including Mycobacterium tuberculosis (Mtb). As a consequence, Mtb has evolved different strategies to hijack the autophagy process. Given the crucial role of human primary dendritic cells (DC) in host immunity control, we characterized Mtb-DC interplay by studying the contribution of cellular microRNAs (miRNAs) in the post-transcriptional regulation of autophagy related genes. From the expression profile of de-regulated miRNAs obtained in Mtb-infected human DC, we identified 7 miRNAs whose expression was previously found to be altered in specimens of TB patients. Among them, gene ontology analysis showed that miR-155, miR-155* and miR-146a target mRNAs with a significant enrichment in biological processes linked to autophagy. Interestingly, miR-155 was significantly stimulated by live and virulent Mtb and enriched in polysome-associated RNA fraction, where actively translated mRNAs reside. The putative pair interaction among the E2 conjugating enzyme involved in LC3-lipidation and autophagosome formation-ATG3-and miR-155 arose by target prediction analysis, was confirmed by both luciferase reporter assay and Atg3 immunoblotting analysis of miR-155-transfected DC, which showed also a consistent Atg3 protein and LC3 lipidated form reduction. Late in infection, when miR-155 expression peaked, both the level of Atg3 and the number of LC3 puncta per cell (autophagosomes) decreased dramatically. In accordance, miR-155 silencing rescued autophagosome number in Mtb infected DC and enhanced autolysosome fusion, thereby supporting a previously unidentified role of the miR-155 as inhibitor of ATG3 expression. Taken together, our findings suggest how Mtb can manipulate cellular miRNA expression to regulate Atg3 for its own survival, and highlight the importance to develop novel therapeutic strategies against tuberculosis that would boost autophagy.
| Original language | English |
|---|---|
| Pages (from-to) | e1006790 |
| Journal | PLoS Pathogens |
| Volume | 14 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Jan 2018 |
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Keywords
- Autophagosomes/immunology
- Autophagy/genetics
- Autophagy-Related Proteins/antagonists & inhibitors
- Cells, Cultured
- Dendritic Cells/metabolism
- Gene Expression Regulation
- HEK293 Cells
- Host-Pathogen Interactions/genetics
- Humans
- MicroRNAs/genetics
- Mycobacterium tuberculosis/immunology
- Ubiquitin-Conjugating Enzymes/antagonists & inhibitors
Cite this
Mycobacterium tuberculosis-induced miR-155 subverts autophagy by targeting ATG3 in human dendritic cells. / Etna, Marilena P; Sinigaglia, Alessandro; Grassi, Angela; Giacomini, Elena; Romagnoli, Alessandra; Pardini, Manuela; Severa, Martina; Cruciani, Melania; Rizzo, Fabiana; Anastasiadou, Eleni; Di Camillo, Barbara; Barzon, Luisa; Fimia, Gian Maria; Manganelli, Riccardo; Coccia, Eliana M.
In: PLoS Pathogens, Vol. 14, No. 1, 01.2018, p. e1006790.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Mycobacterium tuberculosis-induced miR-155 subverts autophagy by targeting ATG3 in human dendritic cells
AU - Etna, Marilena P
AU - Sinigaglia, Alessandro
AU - Grassi, Angela
AU - Giacomini, Elena
AU - Romagnoli, Alessandra
AU - Pardini, Manuela
AU - Severa, Martina
AU - Cruciani, Melania
AU - Rizzo, Fabiana
AU - Anastasiadou, Eleni
AU - Di Camillo, Barbara
AU - Barzon, Luisa
AU - Fimia, Gian Maria
AU - Manganelli, Riccardo
AU - Coccia, Eliana M
PY - 2018/1
Y1 - 2018/1
N2 - Autophagy is a primordial eukaryotic pathway, which provides the immune system with multiple mechanisms for the elimination of invading pathogens including Mycobacterium tuberculosis (Mtb). As a consequence, Mtb has evolved different strategies to hijack the autophagy process. Given the crucial role of human primary dendritic cells (DC) in host immunity control, we characterized Mtb-DC interplay by studying the contribution of cellular microRNAs (miRNAs) in the post-transcriptional regulation of autophagy related genes. From the expression profile of de-regulated miRNAs obtained in Mtb-infected human DC, we identified 7 miRNAs whose expression was previously found to be altered in specimens of TB patients. Among them, gene ontology analysis showed that miR-155, miR-155* and miR-146a target mRNAs with a significant enrichment in biological processes linked to autophagy. Interestingly, miR-155 was significantly stimulated by live and virulent Mtb and enriched in polysome-associated RNA fraction, where actively translated mRNAs reside. The putative pair interaction among the E2 conjugating enzyme involved in LC3-lipidation and autophagosome formation-ATG3-and miR-155 arose by target prediction analysis, was confirmed by both luciferase reporter assay and Atg3 immunoblotting analysis of miR-155-transfected DC, which showed also a consistent Atg3 protein and LC3 lipidated form reduction. Late in infection, when miR-155 expression peaked, both the level of Atg3 and the number of LC3 puncta per cell (autophagosomes) decreased dramatically. In accordance, miR-155 silencing rescued autophagosome number in Mtb infected DC and enhanced autolysosome fusion, thereby supporting a previously unidentified role of the miR-155 as inhibitor of ATG3 expression. Taken together, our findings suggest how Mtb can manipulate cellular miRNA expression to regulate Atg3 for its own survival, and highlight the importance to develop novel therapeutic strategies against tuberculosis that would boost autophagy.
AB - Autophagy is a primordial eukaryotic pathway, which provides the immune system with multiple mechanisms for the elimination of invading pathogens including Mycobacterium tuberculosis (Mtb). As a consequence, Mtb has evolved different strategies to hijack the autophagy process. Given the crucial role of human primary dendritic cells (DC) in host immunity control, we characterized Mtb-DC interplay by studying the contribution of cellular microRNAs (miRNAs) in the post-transcriptional regulation of autophagy related genes. From the expression profile of de-regulated miRNAs obtained in Mtb-infected human DC, we identified 7 miRNAs whose expression was previously found to be altered in specimens of TB patients. Among them, gene ontology analysis showed that miR-155, miR-155* and miR-146a target mRNAs with a significant enrichment in biological processes linked to autophagy. Interestingly, miR-155 was significantly stimulated by live and virulent Mtb and enriched in polysome-associated RNA fraction, where actively translated mRNAs reside. The putative pair interaction among the E2 conjugating enzyme involved in LC3-lipidation and autophagosome formation-ATG3-and miR-155 arose by target prediction analysis, was confirmed by both luciferase reporter assay and Atg3 immunoblotting analysis of miR-155-transfected DC, which showed also a consistent Atg3 protein and LC3 lipidated form reduction. Late in infection, when miR-155 expression peaked, both the level of Atg3 and the number of LC3 puncta per cell (autophagosomes) decreased dramatically. In accordance, miR-155 silencing rescued autophagosome number in Mtb infected DC and enhanced autolysosome fusion, thereby supporting a previously unidentified role of the miR-155 as inhibitor of ATG3 expression. Taken together, our findings suggest how Mtb can manipulate cellular miRNA expression to regulate Atg3 for its own survival, and highlight the importance to develop novel therapeutic strategies against tuberculosis that would boost autophagy.
KW - Autophagosomes/immunology
KW - Autophagy/genetics
KW - Autophagy-Related Proteins/antagonists & inhibitors
KW - Cells, Cultured
KW - Dendritic Cells/metabolism
KW - Gene Expression Regulation
KW - HEK293 Cells
KW - Host-Pathogen Interactions/genetics
KW - Humans
KW - MicroRNAs/genetics
KW - Mycobacterium tuberculosis/immunology
KW - Ubiquitin-Conjugating Enzymes/antagonists & inhibitors
U2 - 10.1371/journal.ppat.1006790
DO - 10.1371/journal.ppat.1006790
M3 - Article
C2 - 29300789
VL - 14
SP - e1006790
JO - PLoS Pathogens
JF - PLoS Pathogens
SN - 1553-7366
IS - 1
ER -