Author(s): Barson HV, Mollenkopf H, Kaufmann SH, Rijpkema S
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Abstract Microarray analysis was used to investigate the effects of Bacillus anthracis lethal toxin (LT) on human neutrophil-like NB-4 cells to identify markers of intoxication. Genes down-regulated after a 2h LT exposure included those encoding chemokines and transcription factors. Significant decreases in the mRNA of interleukin-8, CCL20, CCL3 and CCL4, which are important chemoattractants for immune cells, were observed using real-time PCR (12.3, 4.0, 4.1 and 2.2-fold (p<0.05), respectively). The decreases were more pronounced at 4 and 8h and were LT-specific. Decreases in chemokine protein levels were evident after 24h and were sensitive to low concentrations of LT. Co-incubation with an anti-lethal factor mAb at 500 and 250ng/ml restored levels of interleukin-8 to 100\% and 50\%, respectively. The results reveal that LT suppresses the cellular immune response and that this assay is a useful tool for the analysis of toxin-neutralising antibody activity in a biologically relevant system.
This article was published in Biochem Biophys Res Commun
and referenced in Journal of Bioterrorism & Biodefense