title: [Abnormal dendritic cells mediated immune response in a rat model of visceral hypersensitivity].
abstract: OBJECTIVE
  To explore the role of altered characteristics of intestinal dendritic cell (DC) in the induction of visceral hyperalgesia through the activation of mast cells in a rat model of irritable bowel syndrome (IBS).
  
  
  METHODS
  A total of 20 Sprague-Dawley rats were divided into modeling and control groups (n = 10 each). The IBS rat model was established by combining colorectal distention with restraint stress. Abdominal withdrawal reflex (AWR) was employed to evaluate visceral sensitivity. The surface marker of intestinal DC was analyzed by immunohistochemistry. Toluidine blue staining was used to determine the number of mast cells (MC). The expressions of interleukin (IL) -4 and IL-9 in colonic mucosa were measured by enzyme-linked immunosorbent assay (ELISA) and the level of proteinase-activated receptor-2 (PAR-2) was measured by Western blot. Mesenteric lymph node (MLN) DC and splenic CD4(+)/CD8(+)T cells were isolated and purified by magnetic label-based technique. Cytokine production of MLN DC co-culturing with CD4(+) or CD8(+)T cells was determined.
  
  
  RESULTS
  The number of colonic MC in modeling group was more than that in control group ((2.73 ± 0.21) vs (1.13 ± 0.10), P = 0.000). The expressions of PAR-2, IL-4 and IL-9 in colonic mucosa were all higher than those in control group (2.13 ± 0.81 vs 0.42 ± 0.29, (7.2 ± 1.2) vs (3.3 ± 1.0) pg/ml, (7.3 ± 1.3) vs (5.2 ± 0.6) pg/ml, P = 0.026, 0.000, 0.001). Co-cultured MLN DC with CD4(+) T cells showed a predominant IL-4 secretion in the modeling group ((1.22 ± 0.33) vs (0.80 ± 0.48) pg/ml, P = 0.000).
  
  
  CONCLUSIONS
  Increased colonic DC may stimulate CD4(+) T cells to secrete a high level of IL-4 to cause the degranulation of mast cells and the generation of visceral hypersensitivity in IBS rats.
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital, Zhejiang Chinese Medical University, Hangzhou 310006, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital, Zhejiang Chinese Medical University, Hangzhou 310006, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital, Zhejiang Chinese Medical University, Hangzhou 310006, China. Email: lvbin@medmail.com.cn.
authors.forename: Bin
authors.initials: B
authors.lastname: Lü
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital, Zhejiang Chinese Medical University, Hangzhou 310006, China.
authors.forename: Li-na
authors.initials: LN
authors.lastname: Meng
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital, Zhejiang Chinese Medical University, Hangzhou 310006, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital, Zhejiang Chinese Medical University, Hangzhou 310006, China.
authors.forename: Li
authors.initials: L
authors.lastname: Chu
mesh_terms: D000818:Animals; D003713:Dendritic Cells / Q000276:immunology*; D004195:Disease Models, Animal; D006967:Hypersensitivity / Q000276:immunology*; D015847:Interleukin-4 / Q000378:metabolism; D016906:Interleukin-9 / Q000378:metabolism; D043183:Irritable Bowel Syndrome / Q000276:immunology* / Q000473:pathology*; D008297:Male; D008407:Mast Cells / Q000276:immunology; D051381:Rats; D017207:Rats, Sprague-Dawley; D044464:Receptor, PAR-2 / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism
chemical_list: D016906:Interleukin-9; D044464:Receptor, PAR-2; D015847:Interleukin-4