title: Down-regulation of mechanisms involved in cell transport and maintenance of mucosal integrity in pigs infected with Lawsonia intracellularis.
abstract: Lawsonia intracellularis is an obligate intracellular bacterium, responsible for the disease complex known as proliferative enteropathy (PE). L. intracellularis is associated with intestinal crypt epithelial cell proliferation but the mechanisms responsible are yet to be defined. Microarray analysis was used to investigate the host-pathogen interaction in experimentally infected pigs to identify pathways that may be involved. Ileal samples originating from twenty-eight weaner pigs experimentally challenged with a pure culture of L. intracellularis (strain LR189/5/83) were subjected to microarray analysis. Microarray transcriptional signatures were validated using immunohistochemistry and quantitative real time PCR of selected genes at various time points post challenge. At peak of infection (14 days post challenge) 86% of altered transcripts were down regulated, particularly those involved in maintenance of mucosal integrity and regulation of cell transport. Among the up-regulated transcripts, CD163 and CDK1 were novel findings and considered to be important, due to their respective roles in innate immunity and cellular proliferation. Overall, targeted cellular mechanisms included those that are important in epithelial restitution, migration and protection; maintenance of stable inter-epithelial cell relationships; cell transport of nutrients and electrolytes; innate immunity; and cell cycle.
authors.forename: Sionagh H
authors.initials: SH
authors.lastname: Smith
authors.forename: Alison D
authors.initials: AD
authors.lastname: Wilson
authors.forename: Imke
authors.initials: I
authors.lastname: Van Ettinger
authors.forename: Neil
authors.initials: N
authors.lastname: MacIntyre
authors.forename: Alan L
authors.initials: AL
authors.lastname: Archibald
authors.affiliation: The Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian EH25 9RG, UK. tahar.aitali@roslin.ed.ac.uk.
authors.forename: Tahar
authors.initials: T
authors.lastname: Ait-Ali
mesh_terms: D000818:Animals; D045824:Desulfovibrionaceae Infections / Q000235:genetics / Q000382:microbiology / Q000662:veterinary*; D005786:Gene Expression Regulation; D007082:Ileum; D007150:Immunohistochemistry / Q000662:veterinary; D007413:Intestinal Mucosa / Q000166:cytology / Q000382:microbiology / Q000502:physiology*; D020639:Lawsonia Bacteria / Q000502:physiology*; D020411:Oligonucleotide Array Sequence Analysis / Q000662:veterinary; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D013552:Swine; D013553:Swine Diseases / Q000235:genetics* / Q000382:microbiology