ARS | Publication request: transcriptional response of pigs to Salmonella infection: Comparison of responses to infection with Salmonella eimerica serotype Typhimurium as that observed in S. choleraesuis infection.

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 12, 2007
Publication Date: June 12, 2007
Citation: Lunney, J.K., Bearson S, M.D., Yang, Y.F., Uthe, J.J., Qu, L., Couture, O.P., Zhao, S.H., Kuhar, D.J., Nettleton, D., Dekkers, J.C., Tuggle, C.K. 2007. transcriptional response of pigs to Salmonella infection: Comparison of responses to infection with Salmonella eimerica serotype Typhimurium as that observed in S. choleraesuis infection.

Technical Abstract: Swine responses to, and control of, Salmonella enterica serotype Typhimurium (ST) infection have been compared to S. enterica serotype Choleraesuis (SC) infection. Using subtractive suppression hybridization (SSH), long oligonucleotide Qiagen and Affymetrix porcine GeneChip® arrays, and real time gene expression (Q-PCR), we identified differentially expressed (DE) genes in mesenteric lymph nodes (MLN) and lungs of pigs with acute [8, 24, 48 hours post-inoculation (hpi)], and chronic stages [7, 21 days (dpi)] of infection. The SSH analyses identified several genes involved in heat shock response and cytoskeletal rearrangements. Hierarchical gene cluster and pathway analyses of the microarray data revealed that host protein translation was repressed by both pathogens, and an especially strong transcriptional response at 48 hpi with SC. A high proportion of significantly up-regulated DE genes in both infections are involved in immune pathways; the induction was weaker and occurred earlier in ST (24 hpi) than in SC (48 hpi) infection. This differential transcriptional response was mirrored by interferon gamma and tumor necrosis factor serum protein levels as well as bacterial load in the lymph nodes. Apoptosis and antigen presentation/dendritic cell function pathways were down-regulated at 8 hpi for ST. Cluster analyses, confirmed by Q-PCR analyses, revealed that many DE genes grouped into a specific induced sub-cluster are known NFkB targets. Suppression of NFkB signaling may allow ST to elude a strong inflammatory response to establish a carrier status in pigs. Studies are underway to study Salmonella-cell culture invasion further using IPEC J2 epithelial cells derived from porcine small intestine.