TY - JOUR
T1 - Deletion of a dehydratase important for intracellular growth and cording renders rough Mycobacterium abscessus avirulent
AU - Halloum, Iman
AU - Carrère-Kremer, Séverine
AU - Blaise, Mickael
AU - Viljoen, Albertus
AU - Bernut, Audrey
AU - Le Moigne, Vincent
AU - Vilchèze, Catherine
AU - Guérardel, Yann
AU - Lutfalla, Georges
AU - Herrmann, Jean Louis
AU - Jacobs, William R.
AU - Kremer, Laurent
N1 - Funding Information:
The authors thank J. P. Levraud for the generous gift of csf3r morpholinos. We also thank the staff at ESRF for their help during X-ray data collection. This study was supported by the French National Research Agency (DIMYVIR ANR-13-BSV3-0007-01), the Labex EpiGenMed (I.H.), the Fondation de France (S.C.-K.), and the InfectioPôle Sud (A.V.). L.K. acknowledges the support of Fondation pour la Recherche Médicale (FRM) Grant DEQ20150331719.
PY - 2016/7/19
Y1 - 2016/7/19
N2 - Mycobacterium abscessus (Mabs) is a rapidly growing Mycobacterium and an emerging pathogen in humans. Transitioning from a smooth (S) high-glycopeptidolipid (GPL) producer to a rough (R) low-GPL producer is associated with increased virulence in zebrafish, which involves the formation of massive serpentine cords, abscesses, and rapid larval death. Generating a cord-deficient Mabs mutant would allow us to address the contribution of cording in the physiopathological signs of the R variant. Herein, a deletion mutant of MAB-4780, encoding a dehydratase, distinct from the β-hydroxyacyl-ACP dehydratase HadABC complex, was constructed in the R morphotype. This mutant exhibited an alteration of the mycolic acid composition and a pronounced defect in cording. This correlated with an extremely attenuated phenotype not only in wild-type but also in immunocompromised zebrafish embryos lacking either macrophages or neutrophils. The abolition of granuloma formation in embryos infected with the dehydratase mutant was associated with a failure to replicate in macrophages, presumably due to limited inhibition of the phagolysosomal fusion. Overall, these results indicate that MAB-4780 is required for Mabs to successfully establish acute and lethal infections. Therefore, targeting MAB-4780 may represent an attractive antivirulence strategy to control Mabs infections, refractory to most standard chemotherapeutic interventions. The combination of a dehydratase assay with a highresolution crystal structure of MAB-4780 opens the way to identify such specific inhibitors.
AB - Mycobacterium abscessus (Mabs) is a rapidly growing Mycobacterium and an emerging pathogen in humans. Transitioning from a smooth (S) high-glycopeptidolipid (GPL) producer to a rough (R) low-GPL producer is associated with increased virulence in zebrafish, which involves the formation of massive serpentine cords, abscesses, and rapid larval death. Generating a cord-deficient Mabs mutant would allow us to address the contribution of cording in the physiopathological signs of the R variant. Herein, a deletion mutant of MAB-4780, encoding a dehydratase, distinct from the β-hydroxyacyl-ACP dehydratase HadABC complex, was constructed in the R morphotype. This mutant exhibited an alteration of the mycolic acid composition and a pronounced defect in cording. This correlated with an extremely attenuated phenotype not only in wild-type but also in immunocompromised zebrafish embryos lacking either macrophages or neutrophils. The abolition of granuloma formation in embryos infected with the dehydratase mutant was associated with a failure to replicate in macrophages, presumably due to limited inhibition of the phagolysosomal fusion. Overall, these results indicate that MAB-4780 is required for Mabs to successfully establish acute and lethal infections. Therefore, targeting MAB-4780 may represent an attractive antivirulence strategy to control Mabs infections, refractory to most standard chemotherapeutic interventions. The combination of a dehydratase assay with a highresolution crystal structure of MAB-4780 opens the way to identify such specific inhibitors.
KW - Cording
KW - Dehydratase
KW - M. abscessus
KW - Virulence
KW - Zebrafish
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U2 - 10.1073/pnas.1605477113
DO - 10.1073/pnas.1605477113
M3 - Article
C2 - 27385830
AN - SCOPUS:84978834407
SN - 0027-8424
VL - 113
SP - E4228-E4237
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 29
ER -