Monitoring cellular responses to Listeria monocytogenes with oligonucleotide arrays

Listeria monocytogenes is a pathogenic intracellular microorganism whose in fection induces pleiotropic biological changes associated with host cell ge ne expression regulation, Here we define the gene expression profiles of th e human promyelocytic THP1 cell line before and after L. monocytogenes infe ction. Gene expression was measured on a large scale via oligonucleotide mi croarrays with probe sets corresponding to 6,800 human genes. We assessed a nd discussed the reproducibility of the hybridization signatures. In additi on to oligonucleotide arrays, we also performed the large scale gene expres sion measurement with two high-density membranes, assaying for 588 and 18,3 76 human genes, respectively, This work allowed the reproducible identifica tion of 74 up-regulated RNAs and 23 down-regulated RNAs as a consequence of t. monocytogenes infection of THP1, The reliability of these data was reinf orced by performing independent infections. Some of these detected RNAs wer e consistent with previous results, while some newly identified RNAs encode gene products that may play key roles in L, monocytogenes infection. These findings will undoubtedly enhance the understanding of L, monocytogenes mo lecular physiology and may help identify new therapeutic targets.