Open AccessTranscriptional Profiling of Bacillus anthracis during Infection of Host Macrophages
Author(s) -
Nicholas H. Bergman,
Erica C. Anderson,
Ellen E. Swenson,
Brian K. Janes,
Nathan Fisher,
Matthew M. Niemeyer,
Amy D. Miyoshi,
Philip C. Hanna
Publication year - 2007
Publication title -
infection and immunity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.508
H-Index - 220
eISSN - 1070-6313
pISSN - 0019-9567
DOI - 10.1128/iai.01345-06
Subject(s) - bacillus anthracis , biology , microbiology and biotechnology , phagocyte , gene expression profiling , microarray analysis techniques , intracellular parasite , gene expression , gene , dna microarray , microarray , bacteria , phagocytosis , genetics
The interaction betweenBacillus anthracis and the mammalian phagocyte is one of the central stages in the progression of inhalational anthrax, and it is commonly believed that the host cell plays a key role in facilitating germination and dissemination of inhaledB. anthracis spores. Given this, a detailed definition of the survival strategies used byB. anthracis within the phagocyte is critical for our understanding of anthrax. In this study, we report the first genome-wide analysis ofB. anthracis gene expression during infection of host phagocytes. We developed a technique for specific isolation of bacterial RNA from within infected murine macrophages, and we used customB. anthracis microarrays to characterize the expression patterns occurring within intracellular bacteria throughout infection of the host phagocyte. We found thatB. anthracis adapts very quickly to the intracellular environment, and our analyses identified metabolic pathways that appear to be important to the bacterium during intracellular growth, as well as individual genes that show significant induction in vivo. We used quantitative reverse transcription-PCR to verify that the expression trends that we observed by microarray analysis were valid, and we chose one gene (GBAA1941, encoding a putative transcriptional regulator) for further characterization. A deletion strain missing this gene showed no phenotype in vitro but was significantly attenuated in a mouse model of inhalational anthrax, suggesting that the microarray data described here provide not only the first comprehensive view of howB. anthracis survives within the host cell but also a number of promising leads for further research in anthrax.