Anthrax lethal toxin suppresses chemokine production in human neutrophil NB-4 cells.
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.
Barson
Helen V
HV
Division of Bacteriology, National Institute for Biological Standards and Control, Blanche Lane, Potters Bar, Hertfordshire EN6 3QG, UK. hbarson@nibsc.ac.uk
Mollenkopf
Hans
H
Kaufmann
Stefan H E
SH
Rijpkema
Sjoerd
S
D000942:Antigens, Bacterial / Q000276:immunology* / Q000494:pharmacology; D001427:Bacterial Toxins / Q000276:immunology* / Q000494:pharmacology; D002460:Cell Line; D018925:Chemokines / Q000096:biosynthesis* / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007108:Immune Tolerance / Q000235:genetics; D009504:Neutrophils / Q000187:drug effects / Q000276:immunology*; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics
D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D018925:Chemokines; D012333:RNA, Messenger; D014157:Transcription Factors; C030325:anthrax toxin