Transcriptional Response of Chicken Macrophages to <i>Salmonella enteric</i><i>a</i> Serovar Enteritidis Infection

Abstract

The transcriptional profiles of chicken macrophages (HD11) infected with Salmonella enterica serovar Enteritidis (SE) were analyzed by using an avian macrophage microarray and real time RT-PCR. Out of 4906 array elements interrogated, 269 genes exhibited a 2 fold change (P < 0.001) over a 24 h time-course. Genes coding for proinflammatory cytokines, CC and CXC chemokines, and chemokine ligand were upregulated; whereas genes associated with transcription, cell adhesion and proliferation were downregulated. Most transcriptional changes occurred at 5 hours post-inoculation (hpi), with more genes downregulated than upregulated.At 5 hpi, the levels of gallinacin 1, lymphotactin, RhoA, and MHCIB2M transcripts were significantly decreased. In contrast, the levels of Cdc42 and MHCIIBLB2 mRNA were elevated. Infection of HD11 cells with mutant SE strains carrying an inactivated type three secretion system (TTSS1 or TTSS2) induced significantly higher levels of CCL4, K203, lymphotactin, and RhoA than wild type SE. In conclusion, chicken macrophage genes belonging to diverse functional classes were transcriptionally modulated by SE and selective modulation of host innate responses involved the effectors of TTSS1/2.