title: Interferon-gamma induces polymeric immunoglobulin receptor mRNA in human intestinal epithelial cells by a protein synthesis dependent mechanism.
abstract: Transport of secretory IgA into external fluids is mediated by the polymeric immunoglobulin receptor (pIgR) on the surface of mucosal epithelial cells. We studied the mechanism by which interferon-gamma (IFN-gamma) induces pIgR expression in HT-29.74 cells, a subclone of the HT-29 cell line selected for high concns of pIgR. Here we report the isolation of genomic DNA and cDNA clones encoding human pIgR and development of a sensitive ribonuclease protection assay for pIgR mRNA. This assay was used to determine if induction of pIgR by IFN-gamma is mediated by accumulation of pIgR mRNA. After an initial lag of 12 hr, pIgR mRNA increased seven-fold in response to IFN-gamma, reaching a plateau at 24 hr. Concentrations of pIgR protein also increased seven-fold, but the increase was delayed until 48 hr following stimulation with IFN-gamma. Cycloheximide treatment abolished the IFN-gamma induced increase in pIgR mRNA, indicating that induction of pIgR mRNA by IFN-gamma requires de novo protein synthesis. These results suggest that induction of pIgR expression by IFN-gamma involves an increase in steady-state concns of pIgR mRNA via a protein synthesis dependent mechanism.
authors.affiliation: Institute of Pathology, Case Western Reserve University, Cleveland, OH 44106.
authors.forename: J F
authors.initials: JF
authors.lastname: Piskurich
authors.forename: J A
authors.initials: JA
authors.lastname: France
authors.forename: C M
authors.initials: CM
authors.lastname: Tamer
authors.forename: C A
authors.initials: CA
authors.lastname: Willmer
authors.forename: C S
authors.initials: CS
authors.lastname: Kaetzel
authors.forename: D M
authors.initials: DM
authors.lastname: Kaetzel
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003110:Colonic Neoplasms; D003513:Cycloheximide / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D007413:Intestinal Mucosa / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis*; D011971:Receptors, Immunologic; D011994:Recombinant Proteins; D012635:Secretory Component / Q000096:biosynthesis* / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects*; D014407:Tumor Cells, Cultured
chemical_list: D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D011971:Receptors, Immunologic; D011994:Recombinant Proteins; D012635:Secretory Component; D007371:Interferon-gamma; D004247:DNA; D003513:Cycloheximide