Affordable Access

deepdyve-link
Publisher Website

IgG trafficking in the adult pig small intestine: one- or bidirectional transfer across the enterocyte brush border?

Authors
  • Möller, Rebecca1, 2
  • Hansen, Gert H1
  • Danielsen, E Michael3
  • 1 Department of Cellular and Molecular Medicine, Faculty of Health Sciences, The Panum Institute, University of Copenhagen, Building 18.2.36 Blegdamsvej 3, 2200, Copenhagen, Denmark. , (Denmark)
  • 2 Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, Hannover, Germany. , (Germany)
  • 3 Department of Cellular and Molecular Medicine, Faculty of Health Sciences, The Panum Institute, University of Copenhagen, Building 18.2.36 Blegdamsvej 3, 2200, Copenhagen, Denmark. [email protected] , (Denmark)
Type
Published Article
Journal
Histochemistry and cell biology
Publication Date
Mar 01, 2017
Volume
147
Issue
3
Pages
399–411
Identifiers
DOI: 10.1007/s00418-016-1492-x
PMID: 27646280
Source
Medline
Keywords
License
Unknown

Abstract

Immunoglobulin G (IgG) transfer in opposite directions across the small intestinal brush border serves different purposes in early life and in adulthood. In the neonate, maternal IgG is taken up from the gut lumen into the blood, conferring passive immunity to the offspring, whereas in the adult immunoglobulins, including IgG made by plasma cells in the lamina propria, are secreted via the brush border to the lumen as part of the mucosal defense. Here, IgG has been proposed to perform a luminal immune surveillance which eventually includes a reuptake through the brush border as pathogen-containing immune complexes. In the present work, we studied luminal uptake of FITC-conjugated and gold-conjugated IgG in cultured pig jejunal mucosal explants. After 1 h, binding to the brush border was seen in upper crypts and lower parts of the villi. However, no endocytotic uptake into EEA-1-positive compartments was detected, neither at neutral nor acidic pH, despite an ongoing constitutive endocytosis from the brush border, visualized by the polar tracer CF594. The 40-kDa neonatal Fc receptor, FcRn, was present in the microvillus fraction, but noteworthy, a 37 kDa band, most likely a proteolytic cleavage product, bound IgG in a pH-dependent manner more efficiently than did the full-length FcRn. In conclusion, our work does not support the theory that bidirectional transfer of IgG across the intestinal brush border is part of the luminal immune surveillance in the adult.

Report this publication

Statistics

Seen <100 times