title: Tumor necrosis factor-alpha upregulates the expression of immunoglobulin secretory component.
abstract: BACKGROUND
  The immunoglobulin (Ig) secretory component (SC) is the extracellular component of the polymeric Ig receptor (plgR) that is responsible for the transcytosis of newly synthesized IgA. In addition, the SC seems to play important roles in regulating eosinophil functions and in enhancing local immune responses. SC expression in HT-29 has been shown to increase in response to interferon-gamma, interleukin (IL) 4 and IL-1, but whether tumor necrosis factor (TNF) alpha affects SC expression is disputed.
  
  
  OBJECTIVE
  Our aim was to study whether TNF-alpha can affect the expression of SC in Caco-2 cells.
  
  
  METHODS
  We used immunocytochemistry, enzyme-linked immunosorbent assay, Western blot, and quantitative real-time polymerase chain reaction to test SC-positive cells, free SC in culture supernatants, plgR mRNA, and protein expression of SC.
  
  
  RESULTS
  TNF-alpha dose-dependently increased SC-positive cells, free SC in culture supernatants, plgR mRNA, and protein expression of SC.
authors.affiliation: Clinical Hospital Department of Medical Examination, China Medical University No. 2, Shenyang, China.
authors.forename: D Y
authors.initials: DY
authors.lastname: Liu
authors.forename: X L
authors.initials: XL
authors.lastname: Wang
authors.forename: P
authors.initials: P
authors.lastname: Liu
mesh_terms: D018938:Caco-2 Cells; D006801:Humans; D007070:Immunoglobulin A / Q000378:metabolism*; D019056:Receptors, Polymeric Immunoglobulin / Q000235:genetics* / Q000378:metabolism; D012635:Secretory Component / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology*; D015854:Up-Regulation
chemical_list: D007070:Immunoglobulin A; D019056:Receptors, Polymeric Immunoglobulin; D012635:Secretory Component; D014409:Tumor Necrosis Factor-alpha