title: Differential lamina propria cell migration via basement membrane pores of inflammatory bowel disease mucosa.
abstract: OBJECTIVE
  In active inflammatory bowel disease (IBD), the intestinal mucosa is infiltrated by polymorphonuclear cells (PMNs), lymphocytes, and monocytes from the systemic circulation. Using an ex vivo model, we have investigated luminally directed migration of cells out of the lamina propria.
  
  
  METHODS
  Fresh untreated and deepithelialized mucosal samples were studied by electron microscopy. Cells migrating out of the lamina propria were investigated by immunohistochemistry and fluorescence-activated cell sorter analysis.
  
  
  RESULTS
  In intact IBD mucosal samples, tunnels containing cells were prominent in the lamina propria matrix, and PMNs, but not other cell types, were prominent in the epithelium. In deepithelialized mucosal samples, the basement membrane was either destroyed or contained numerous large pores. During culture of deepithelialized mucosal samples, many cells (3.3 [+/-0.8] x 10(5) . g tissue-1 . h-1) migrated out of the lamina propria via basement membrane pores. PMNs and eosinophils were prominent during the first 3 hours of culture, but T cells predominated thereafter. Macrophages also migrated, but B cells were the minority population (<2%) at all times.
  
  
  CONCLUSIONS
  In active IBD mucosa with an intact epithelium, luminally directed migration of lamina propria cells is restricted mainly to PMNs. After loss of the epithelium, other cell types also migrate into the lumen via numerous, large, basement membrane pores.
authors.affiliation: Division of Gastroenterology, University Hospital, Nottingham, England.
authors.forename: M E
authors.initials: ME
authors.lastname: McAlindon
authors.forename: T
authors.initials: T
authors.lastname: Gray
authors.forename: A
authors.initials: A
authors.lastname: Galvin
authors.forename: H F
authors.initials: HF
authors.lastname: Sewell
authors.forename: D K
authors.initials: DK
authors.lastname: Podolsky
authors.forename: Y R
authors.initials: YR
authors.lastname: Mahida
mesh_terms: D001485:Basement Membrane / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology; D002469:Cell Separation; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D015212:Inflammatory Bowel Diseases / Q000473:pathology* / Q000503:physiopathology; D007413:Intestinal Mucosa / Q000473:pathology*; D008297:Male; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D010641:Phenotype