Lack of SC/pIgR-mediated epithelial transport of a human polymeric IgA devoid of J chain: in vitro and in vivo studies

Immunology. 1998 Sep;95(1):90-6. doi: 10.1046/j.1365-2567.1998.00560.x.


Three human polymeric IgA (pIgA) myeloma proteins of tetrameric size were compared for their J-chain content, their in vitro secretory component (SC)-binding ability, and their capacity to be transcytosed by polymeric immunoglobulin receptor (pIgR)-expressing epithelial cells in vitro and rat hepatocytes in vivo. One of the three pIgA preparations, pIgA-L, was shown to lack J chain and was unable to combine with purified free human and rat SC, whereas pIgA-G and pIgA-C contained J chain and combined readily with SC. Furthermore, pIgA-L was not transferred into rat bile after intravenous injection, and was hardly transported apically by polarized Madin-Darbey canine kidney cell monolayers expressing the human pIgR, whereas pIgA-G and pIgA-C were efficiently transported in both test systems. Together with our recent demonstration that antibodies to human J chain block the SC/pIgR-mediated epithelial transport of pIgA, these data unanimously confirm the proposed key role of J chain in the epithelial transport of polymeric immunoglobulins into exocrine secretions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bile / immunology
  • Bile / metabolism
  • Biological Transport
  • Cells, Cultured
  • Dogs
  • Electrophoresis
  • Epithelial Cells / metabolism
  • Humans
  • Immunoelectrophoresis
  • Immunoglobulin A*
  • Immunoglobulin J-Chains*
  • Infant, Newborn
  • Multiple Myeloma / immunology*
  • Multiple Myeloma / metabolism
  • Myeloma Proteins / immunology*
  • Myeloma Proteins / isolation & purification
  • Myeloma Proteins / metabolism
  • Protein Binding
  • Rats
  • Receptors, Immunologic / metabolism
  • Receptors, Polymeric Immunoglobulin / metabolism*
  • Secretory Component / metabolism*
  • Ultracentrifugation


  • Immunoglobulin A
  • Immunoglobulin J-Chains
  • Myeloma Proteins
  • Receptors, Immunologic
  • Receptors, Polymeric Immunoglobulin
  • Secretory Component