Global transcriptional response of porcine mesenteric lymph nodes to Salmonella enterica serovar Typhimurium

Abstract

<p>To elucidate the host transcriptional response to <em>Salmonella enterica</em> serovar Typhimurium, Affymetrix porcine GeneChip analysis of pig mesenteric lymph nodes was used to identify 848 genes showing differential expression across different times after <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/inoculation" title="Learn more about Inoculation from ScienceDirect's AI-generated Topic Pages">inoculation</a> or when compared to non-inoculated controls. Annotation analyses showed that a high proportion of these differentially expressed (DE) genes are involved in immune and inflammatory responses. T helper 1, innate/inflammatory, and <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/antigen-presentation" title="Learn more about Antigen Presentation from ScienceDirect's AI-generated Topic Pages">antigen-processing</a> pathways were induced at 24 h post-inoculation (hpi) and/or 48 hpi, while <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/apoptosis" title="Learn more about Apoptosis from ScienceDirect's AI-generated Topic Pages">apoptosis</a> and antigen presentation/dendritic cell function pathways were downregulated at 8 hpi. Cluster analyses revealed that most DE genes annotated as NFκB targets were grouped into a specific induced subcluster, while many translation-related DE genes were found in a repressed subcluster. Quantitative polymerase chain reaction analyses confirmed the Affymetrix results, revealing transcriptional induction of NFκB target genes at 24 hpi and suppression of the NFκB pathway from 24 to 48 hpi. We propose that such NFκB suppression in <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/antigen-presenting-cell" title="Learn more about Antigen-Presenting Cell from ScienceDirect's AI-generated Topic Pages">antigen-presenting cells</a> may be the mechanism by which <em>S</em>. Typhimurium eludes a strong inflammatory response to establish a carrier status in pigs.</p>