Transcriptional responses of murine macrophages to the adenylate cyclase toxin of Bordetella pertussis

Three different recombinant forms of CyaA were used to investigate transcriptional responses of murine bone marrow-derived macrophages (BMDMs) using Affymetrix Mouse Genome Genechips. These forms were enzymically active, invasive CyaA, nonenzymically active, invasive CyaA (CyaA*) and non-enzymically active, non-invasive CyaA (proCyaA*). BMMs, treated with 20 ng/ml of CyaA for 24 h, showed over 1000 significant changes in gene transcription compared with control cells. CyaA caused an increase in transcription of many inflammatory genes and genes associated with various signalling cascades such as those involved in cyclic AMP-dependent protein kinase A signalling. Most strikingly, CyaA caused down-regulation of numerous genes involved in cell proliferation. CyaA* at 20 ng/ml significantly up-regulated the transcription of only twelve genes after 24 h whereas proCyaA* at this concentration significantly increased the transcription of only two genes.

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Cheung GY, Dickinson P, Sing G, Craigon M, Ghazal P, Parton R, Coote JG