Gene expression profiling of jejunal Peyer’s patches in juvenile and adult pigs

Abstract

Peyer's patches are organized lymphoid tissues of the small intestine that play a critical role in disease resistance and oral tolerance. Peyer's patches in the jejunum contain lymphocytes, dendritic cells, macrophages, villous epithelium, and specialized follicle-associated epithelium. Little is known about the mechanisms and processes by which cells of the Peyer's patches discriminate food nutrients and commensal microflora from pathogenic microbiota. We hypothesize that the jejunal Peyer's patches express genes that mediate and regulate its essential functions. Expression patterns of approximately 2600 cDNAs from a porcine Peyer's patch subtracted library were examined by microarray profiling. Individual mRNAs of interest were further examined by quantitative RT-PCR. Innate immunity-associated genes, including complement 3 and lysozyme, and the genes for epithelial chloride channel and trappin 1 were highly expressed by jejunal Peyer's patch in both juvenile and adult pigs. The growth- and apoptosis-associated genes CIDE-B, GW112, and PSP/Reg I (pancreatic stone protein or regenerating gene) were differentially expressed in juvenile pig Peyer's patches. Many sequences which were highly expressed in jejunal Peyer's patches have previously been described with functions in epithelial cells. Animal-to-animal variation in basal jejunal Peyer's patch gene expression was considerable and reflects the dynamic physiological environment of the gut in addition to genetic, epigenetic, and microbiological variation in the small intestine.

Extensive Expression Differences along Porcine Small Intestine Evidenced by Transcriptome Sequencing

“…These results might reflect the massive regulation of the reorganization of mucosal immune response to food antigens following weaning (which occurred at 28 days of age), aside of constant replacement of enterocytes by regeneration of epithelial cells from crypts and the constant production of protective mucus coat in young pigs [29]. In a similar way, Machado et al [30] reported significantly higher expression of genes associated with growth and apoptosis in the jejunal Peyer's patches in 7-weeks old pigs compared to 6-months old ones. A close examination of these canonical pathways revealed notable difference in expression patterns of individual transcription factors involved in intestine development and cellular function amongst the various segments of the porcine intestine.…”

“…In addition to the physical barrier, the intestinal tissues are also able to provide effective innate defence against luminal threats discriminating between pathogenic microorganisms and harmless substances [30]. During the complete life time, there is a permanent crosstalk among epithelial cells, bacteria and the gut-associated lymphoid tissue (GALT), which are mainly composed of Peyer's patches, mesenteric lymph nodes, and lymphocytes distributed throughout the lamina propria.…”

“…The GALT mediates innate and adaptive responses for specific host defence and oral tolerance induction [37]. The Peyer's patches are complex organised lymphoid tissues containing different immune and non-immune cell types, and expressing proteins involved in major intestinal functions, including nutrient and solute transport, barrier function and mucosal immunity [30]. Our study strengthened that the significant biological functions associated with the ileal Peyer's patches were essential for mucosal innate immune responses, including the role of nuclear factor of activated T-cells (NFAT) in regulation of the immune response, maturation of dendritic cells, CD28 signalling in T helper cells, and T cell receptor signalling.…”

Estudos de expressão gênica utilizando-se microarrays: delineamento, análise, e aplicações na pesquisa zootécnica

“…Contudo, pouco se sabe sobre seus mecanismos de ação, notadamente no que se refere aos processos envolvidos na identificação dos patógenos. Para melhor entender as funções dessas estruturas, Machado et al (2005) investigaram os padrões normais de expressão gênica nas placas de Peyer presentes no jejuno de suínos jovens e adultos, criados sob condições convencionais. Utilizando microarrays de cDNA com 2.604 seqüências gênicas, estes autores verificaram que tanto nos animais jovens, quanto nos adultos, as placas de Peyer apresentavam diversos genes relacionados com a imunidade inata estimulados, enquanto que um grupo de genes relacionados com o crescimento celular e com a apoptose tiveram a alterações histológicas em peixes, produzindo inclusive o hermafroditismo e induzindo a produção de vitelogenina (característica de fêmeas sexualmente maduras) em indivíduos machos.…”

The porcine genome initiative: Implications for digestive physiology

“…This microarray is comprised of 70-mer oligonucleotide (Qiagen-NRSP8 array) and has been recently validated and shown to be informative and specific and thus an appropriate tool for porcine functional genomics studies and for modeling the pig in physiological questions. Recently Machado et al (2005) have used this functional genomics approach to monitor changes in gene expression in jejunal Peyer's patches in both juvenile and adult pigs.…”