Novel markers of the human follicle-associated epithelium identified by genomic profiling and microdissection.
OBJECTIVE
Regulation of gene expression in the follicle-associated epithelium (FAE) over Peyer's patches is largely unknown. CCL20, a chemokine that recruits immature dendritic cells, is one of the few FAE-specific markers described so far. Lymphotoxin beta (LTalpha1beta2) expressed on the membrane of immune cells triggers CCL20 expression in enterocytes. In this study, we measured expression profiles of LTalpha1beta2-treated intestinal epithelial cells and selected CCL20 -coregulated genes to identify new FAE markers.


METHODS
Genomic profiles of T84 and Caco-2 cell lines treated with either LTalpha1beta2, flagellin, or tumor necrosis factor alpha were measured using the Affymetrix GeneChip U133A. Clustering analysis was used to select CCL20 -coregulated genes, and laser dissection microscopy and real-time polymerase chain reaction on human biopsy specimens was used to assess the expression of the selected markers.


RESULTS
Applying a 2-way analysis of variance, we identified regulated genes upon the different treatments. A subset of genes involved in inflammation and related to the nuclear factor kappaB pathway was coregulated with CCL20 . Among these genes, the antiapoptotic factor TNFAIP3 was highly expressed in the FAE. CCL23 , which was not coregulated in vitro with CCL20 , was also specifically expressed in the FAE.


CONCLUSIONS
We have identified 2 novel human FAE specifically expressed genes. Most of the CCL20 -coregulated genes did not show FAE-specific expression, suggesting that other signaling pathways are critical to modulate FAE-specific gene expression.
Anderle
Pascale
P
Swiss Institute for Experimental Cancer Research and Institute of Biochemistry, University of Lausanne, Epalinges, Switzerland.
Rumbo
Martin
M
Sierro
Frédéric
F
Mansourian
Robert
R
Michetti
Pierre
P
Roberts
Matthew A
MA
Kraehenbuhl
Jean-Pierre
JP
D015415:Biomarkers; D018938:Caco-2 Cells; D019742:Chemokines, CC / Q000235:genetics; D004268:DNA-Binding Proteins; D005408:Flagellin / Q000235:genetics; D023281:Genomics / Q000379:methods*; D006801:Humans; D007413:Intestinal Mucosa / Q000502:physiology*; D047908:Intracellular Signaling Peptides and Proteins; D007834:Lasers; D008233:Lymphotoxin-alpha / Q000235:genetics; D053308:Lymphotoxin-beta; D008565:Membrane Proteins / Q000235:genetics; D042282:Microdissection; D005810:Multigene Family; D009687:Nuclear Proteins; D010641:Phenotype; D016133:Polymerase Chain Reaction; D011506:Proteins / Q000235:genetics; D000072598:Tumor Necrosis Factor alpha-Induced Protein 3; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
D015415:Biomarkers; C105504:CCL23 protein, human; D019742:Chemokines, CC; D004268:DNA-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; C505886:LTB protein, human; D008233:Lymphotoxin-alpha; D053308:Lymphotoxin-beta; D008565:Membrane Proteins; D009687:Nuclear Proteins; D011506:Proteins; D014409:Tumor Necrosis Factor-alpha; D005408:Flagellin; C076529:TNFAIP3 protein, human; D000072598:Tumor Necrosis Factor alpha-Induced Protein 3