title: Establishment of a functional secretory IgA transcytosis model system in vitro for functional food screening.
abstract: A characteristic mucosal immune response involves the production of antigen-specific secretory immunoglobulin A (SIgA) antibodies. In order to study transcytosis by mimicking the SIgA secretion and to screen for SIgA secretion-promoting substances, we developed a model system of a transfected Madin-Darby canine kidney (MDCK) cell line that expresses the human polymeric immunoglobulin receptor (pIgR). We thus isolated the human dIgA (dimeric IgA)/pIgA (polymeric IgA) complex as the binding ligands. In the present study, a recombinant vector encoding the human pIgR gene was constructed and infected into MDCK cells. Following reverse transcription polymerase chain reaction (RT-PCR), immunoblotting, and immunofluorescence staining, we confirmed that pIgR was expressed in the transfectant MDCK-pIgR cells and was located at the basolateral side of the cell surface. We also confirmed the coexistence of the dIgA/pIgA complex in the IgA myeloma serum. The covalent dIgA/pIgA complex was then isolated from the serum of an IgA multiple myeloma patient using an ÄKTA purifier operation system with a HiPrep 16/60 Sephacryl S-300 HR column, in order to utilize the complex as transcytosis ligands for human pIgR. Finally, we confirmed the uptake of the isolated human dIgA/pIgA complex into MDCK-pIgR cells. We demonstrated that the human dIgA/pIgA complex was transcytosed into the apical side of the monolayer cells. Therefore, our MDCK-human pIgR cell transcytosis model is an operational system and can be used for screening functional food components that promote dIgA/pIgR transcytosis as well as SIgA secretion.
authors.affiliation: College of Food Science and Engineering, Ocean University of China, 5 Yushan Road, Qingdao, 266003, Shandong Province, People's Republic of China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zuo
authors.forename: Xianqi
authors.initials: X
authors.lastname: Feng
authors.forename: Na
authors.initials: N
authors.lastname: Zhang
authors.forename: Changhu
authors.initials: C
authors.lastname: Xue
authors.forename: Qing-Juan
authors.initials: QJ
authors.lastname: Tang
mesh_terms: D000818:Animals; D004285:Dogs; D005455:Fluorescent Antibody Technique; D055951:Functional Food; D006801:Humans; D015151:Immunoblotting; D007070:Immunoglobulin A / Q000097:blood; D007071:Immunoglobulin A, Secretory / Q000378:metabolism*; D061985:Madin Darby Canine Kidney Cells; D008403:Mass Screening / Q000379:methods*; D008954:Models, Biological; D009101:Multiple Myeloma / Q000276:immunology; D019056:Receptors, Polymeric Immunoglobulin / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D044967:Serum / Q000276:immunology; D057900:Transcytosis; D019076:Transgenes
chemical_list: D007070:Immunoglobulin A; D007071:Immunoglobulin A, Secretory; D019056:Receptors, Polymeric Immunoglobulin; D011994:Recombinant Proteins; C034639:polymeric IgA