Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/5/2006
Publication Date: 8/3/2006
Citation: Wang, Y.F., Uthe, J.J., Bearson, S.M., Kuhar, D.J., Lunney, J.K., Qu, L., Nettleton, D., Tuggle, C.K. Lack of a strong nfkb-dependent transcriptional response during infection with Salmonella enterica serovar Typhimurium as compared to that observed in Salmonella Choleraesuis infection [abstract]. International Society of Animal Genetics. p. 264.
Technical Abstract: Salmonellosis is prevalent worldwide and is a food safety issue and production problem. Classic salmonellae of pigs are S. enterica serovar Choleraesuis (SC) and Typhimurium (ST), the latter also being a significant human pathogen. To understand the host transcriptional response to infection, total RNA was collected from mesenteric lymph nodes of uninfected pigs and pigs inoculated with ST or SC at 8, 24 or 48 hours post-inoculation (HPI) (n=24 pigs). Affymetrix porcine GeneChip® were used to identify genes responding to infection. An ANOVA analysis showed that, compared with uninfected pigs, 173 genes, 224 genes and 179 genes changed their expression level (P<0.01, Fold change (fc)>2, q<0.24) at 8HPI, 24HPI and 48HPI, respectively, during ST infection. During the SC infection, 150 genes, 251 genes and 1175 genes were differentially expressed at 8HPI, 24HPI and 48HPI respectively (P<0.01, fc>2, q<0.26). The transcriptionally-induced genes were further examined using PathwayStudio software to determine which immune pathways were up-regulated. In the SC infection, the expression of known NFkB-regulated genes, such as proinflammatory cytokines (IL1B, IL6, IFN-'), chemokines (IL-8, MCP-1), adhesion molecules (ICAM1) and many other NFkB-dependent genes (e.g., IkBa, JUNB, COX-2, PTGES, IL1A, BCL2, ALOX12) increased significantly at either 24HPI or 48HPI. Verification by QPCR is underway for these genes. Interestingly, in the ST infection, only a few NFkB-dependent genes were transiently induced at 24HPI and most decreased their RNA levels from 24HPI to 48HPI. This indicated that NFkB-dependent pathways were evaded, or even suppressed, in pigs with ST infection relative to those with SC infection. These results suggest a mechanism by which infection with ST eludes the strong inflammatory response shown with SC infection, and progresses into a carrier state in the pig.