title: Expression of polymeric immunoglobulin receptor mRNA and protein in human paneth cells: Paneth cells participate in acquired immunity.
abstract: OBJECTIVE
  Paneth cells are important effectors of intestinal innate immunity. It has been generally accepted that Paneth cells do not participate in the synthesis of polymeric immunoglobulin receptor (pIgR) or the secretion of immunoglobulin A (IgA) in the small intestine. However, we have previously shown that pIgR is specifically localized in Paneth cells of the rat small intestine. We therefore investigated the possibility that pIgR is also localized in human Paneth cells.
  
  
  METHODS
  Double-labeled fluorescent immunohistochemistry and double-labeled fluorescent in situ hybridization were used to determine RNA and protein expression in normal human small intestine.
  
  
  RESULTS
  Both pIgR mRNA and protein were colocalized with lysozyme in normal human Paneth cells. Furthermore, IgA was colocalized with lysozyme in the secretory granules of human Paneth cells.
  
  
  CONCLUSIONS
  This is the first study to demonstrate that pIgR and IgA are colocalized in the secretory granules of human Paneth cells. These findings suggest that, in addition to their well-recognized role in innate immunity, Paneth cells are involved in IgA-mediated acquired immunity in the gastrointestinal tract. Furthermore, these results add to accumulating evidence that Paneth cells participate in intestinal inflammation.
authors.affiliation: Department of Molecular Pharmacology, Marine Drug and Food Institute, Ocean University of China, Qingdao, PR China.
authors.forename: Qing-Juan
authors.initials: QJ
authors.lastname: Tang
authors.forename: Li-Mei
authors.initials: LM
authors.lastname: Wang
authors.forename: Kai-Zhong
authors.initials: KZ
authors.lastname: Tao
authors.forename: Chang-Rong
authors.initials: CR
authors.lastname: Ge
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Yun-Li
authors.initials: YL
authors.lastname: Peng
authors.forename: Chun-Lei
authors.initials: CL
authors.lastname: Jiang
authors.forename: Mei-Yu
authors.initials: MY
authors.lastname: Geng
mesh_terms: D006801:Humans; D007124:Immunoenzyme Techniques; D007070:Immunoglobulin A / Q000378:metabolism*; D017404:In Situ Hybridization, Fluorescence; D007421:Intestine, Small / Q000166:cytology / Q000378:metabolism*; D019879:Paneth Cells / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D019056:Receptors, Polymeric Immunoglobulin / Q000378:metabolism*
chemical_list: D007070:Immunoglobulin A; D012333:RNA, Messenger; D019056:Receptors, Polymeric Immunoglobulin