Identification of Mycobacterium avium genes up-regulated in cultured macrophages and in mice.

TitleIdentification of Mycobacterium avium genes up-regulated in cultured macrophages and in mice.
Publication TypeJournal Article
Year of Publication2004
AuthorsDanelishvili L, Poort MJ, Bermudez LE
JournalFEMS microbiology letters
Volume239
Issue1
Pagination41-9
Date Published2004 Oct 1
ISSN0378-1097
KeywordsAnimals, Bacterial Proteins, Gene Library, Green Fluorescent Proteins, Humans, Macrophages, Mice, Mice, Inbred C57BL, Molecular Sequence Data, Mycobacterium avium, Mycobacterium smegmatis, Reverse Transcriptase Polymerase Chain Reaction, Sequence Analysis, DNA, Tuberculosis, U937 Cells, Up-Regulation
Abstract

To investigate Mycobacterium avium gene expression upon infection of macrophages, we created a M. avium-promoter library upstream of a promoter-less gene encoding the green fluorescent protein (GFP) in Mycobacterium smegmatis. Clones were evaluated for increased expression of GFP after infection of U937 macrophages. A number of M. avium genes were up-regulated more than 3-fold after 24 and 48 h following macrophage infection. M. avium genes expressed by M. smegmatis during growth in macrophages include genes encoding transport/binding proteins, synthesis, modification and degradation of macromolecules, and a great majority of genes for which no function is currently known. For some of the unknown genes, homologues were identified in bacteria such as Mycobacterium leprae, Salmonella typhimurium and Agrobacterium tumefaciens. In order to investigate if these genes were also expressed in M. avium during macrophage infection in vitro and in vivo, transcripts of selected genes were quantified using real time RT-PCR. Evaluation of most expressed genes in M. smegmatis confirmed their up-regulation in M. avium after 24 h infection of macrophages in vitro and mice.

Alternate JournalFEMS Microbiol. Lett.