A Mycobacterium avium subsp. paratuberculosis LuxR regulates cell envelope and virulence.

TitleA Mycobacterium avium subsp. paratuberculosis LuxR regulates cell envelope and virulence.
Publication TypeJournal Article
Year of Publication2010
AuthorsAlonso-Hearn M, Eckstein TM, Sommer S, Bermudez LE
JournalInnate immunity
Volume16
Issue4
Pagination235-47
Date Published2010 Aug
ISSN1753-4267
KeywordsAnimals, Anti-Bacterial Agents, Cattle, Cell Line, Cell Wall, Culture Media, DNA, Bacterial, Gene Expression Regulation, Bacterial, Lipids, Microarray Analysis, Milk, Mycobacterium avium subsp. paratuberculosis, Peptides, Repressor Proteins, Reverse Transcriptase Polymerase Chain Reaction, RNA, Bacterial, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Trans-Activators, Transcription, Genetic, Virulence
Abstract

Mycobacterium avium subsp. paratuberculosis adapts to the environment via the regulation of genes affecting its envelope's composition. Bacteria grown in milk (in vivo conditions) presented differences in the cell wall-associated lipids and in the expression of genes involved in lipid metabolism (FadE8, FadE6 and MAP1420) and host cell invasion (MAP1203, LprL). A different lipid profile was also observed in the envelope of intracellular bacteria after 1 h of infection. Intracellular bacteria showed up-regulation of a LuxR regulator which controls the envelope's composition by up-regulation of FadE8, MAP1420, MAP1203 and LprL and by down-regulation of pks12, mmpL2 and MAP2594. A LuxR-overexpressing strain with a lipid-deficient envelope phenotype, infected epithelial cells more efficiently than the wild-type bacteria; however, it was not more resistant than the wild-type strain to the action of bactericidal proteins. Here we show that LuxR regulates virulence determinants and is involved in mycobacteria adaptation to the host.

DOI10.1111/j.1365-3164.2011.00980.x
Alternate JournalInnate Immun