| Sungdo Park | 1 Article |
Objectives
The objective of this study was to isolate a <i>Brucella lon</i> mutant and to analyze the cytokine response of <i>B. lon</i> mutant during macrophage infection. Methods A wild-type <i>Brucella abortus</i> strain was mutagenized by Tn5 transposition. From the mouse macrophage J774.A1 cells, total RNA was isolated at 0 hours, 6 hours, 12 hours, and 24 hours after infection with <i>Brucella</i>. Using mouse cytokine microarrays, we measured transcriptional levels of the cytokine response, and validated our results with a reverse transcriptase-polymerase chain reaction (RT-PCR) assay to confirm the induction of cytokine messenger RNA (mRNA). Results In host J774.A1 macrophages, mRNA levels of T helper 1 (Th1)-type cytokines, including tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), interleukin-2 (IL-2), and IL-3, were significantly higher in the <i>lon</i> mutant compared to wild-type <i>Brucella</i> and the negative control. TNF-α levels in cell culture media were induced as high as 2 μg/mL after infection with the <i>lon</i> mutant, a greater than sixfold change. Conclusion In order to understand the role of the lon protein in virulence, we identified and characterized a novel <i>B. lon</i> mutant. We compared the immune response it generates to the wild-type <i>Brucella</i> response in a mouse macrophage cell line. We demonstrated that the <i>B. lon</i> mutants induce TNF-α expression from the host J774.A1 macrophage. Citations
Citations to this article as recorded by
|
|
