Pharmaceutical Research

, Volume 23, Issue 2, pp 270–279

Expression and Transport Functionality of FcRn within Rat Alveolar Epithelium: A Study in Primary Cell Culture and in the Isolated Perfused Lung

  • Masahiro Sakagami
  • Yadollah Omidi
  • Lee Campbell
  • Lana E. Kandalaft
  • Christopher J. Morris
  • Jaleh Barar
  • Mark Gumbleton
Research Paper

DOI: 10.1007/s11095-005-9226-0

Cite this article as:
Sakagami, M., Omidi, Y., Campbell, L. et al. Pharm Res (2006) 23: 270. doi:10.1007/s11095-005-9226-0

Purpose

The neonatal constant region fragment receptor (FcRn) binds and transports IgG. FcRn expression in the upper tracheobronchial airways of the lung is recognized. In this study, we sought to characterize the functional expression of FcRn within alveolar regions of lung tissue.

Methods

FcRn immunohistochemistry was performed on intact rat lung. FcRn expression [Western blot, reverse transcription–polymerase chain reaction (RT-PCR), and immunofluorescence microscopy] and IgG transport functionality were assessed in an in vitro rat alveolar epithelial primary cell culture model. An isolated perfused rat lung model was used to examine IgG transport across pulmonary epithelium from airspace to perfusate.

Results

FcRn is expressed in intact alveolar epithelium, substantiated by expression and functionality in an in vitro alveolar epithelial model within which IgG transport was temperature sensitive, concentration dependent, and inhibited by excess unlabeled IgG and, to a disproportionate level, by anti-FcRn antibody. Saturable IgG transport across pulmonary epithelium was evident in an isolated perfused rat lung, inhibitable by competing IgG, and displayed a relatively low maximal net IgG absorptive rate of approximately 80 ng/h.

Conclusion

Pulmonary epithelium expresses functional FcRn providing an absorption pathway potentially important for highly potent Fcγ-fusion proteins but unlikely to be of quantitative significance for the systemic delivery of inhaled therapeutic monoclonal IgGs.

Key Words

IgGisolated perfused lunglungneonatal constant region fragment receptor (FcRn)transport

Abbreviations

AE

alveolar epithelial

BSA

bovine serum albumin

cDNA

complementary deoxyribonucleic acid

DMEM

Dulbecco's modified Eagle medium

EDTA

ethylenediaminetetraacetic acid

ELISA

enzyme-linked immunosorbent assay

FBS

fetal bovine serum

FcRn

neonatal Fc receptor

FITC

fluorescein isothiocyanate

HRP

horseradish peroxide

IgG

immunoglobulin G

IPRL

isolated perfused rat lung

MDI

metered dose inhaler

MHC

major histocompatibility complex

MWCO

molecular weight cutoff

NIH

National Institute of Health

RT

reverse transcriptase

RT-PCR

reverse transcription–polymerase chain reaction

SDS-PAGE

sodium dodecyl sulfate–polyacrylamide gel electrophoresis

TBST

Tris-buffered saline with Tween 20

tRNA

total RNA

UV

ultraviolet

Copyright information

© Springer Science + Business Media, Inc. 2006

Authors and Affiliations

  • Masahiro Sakagami
    • 1
  • Yadollah Omidi
    • 2
    • 3
  • Lee Campbell
    • 2
  • Lana E. Kandalaft
    • 2
  • Christopher J. Morris
    • 2
  • Jaleh Barar
    • 2
    • 3
  • Mark Gumbleton
    • 2
  1. 1.Department of Pharmaceutics, School of PharmacyVirginia Commonwealth UniversityRichmondUSA
  2. 2.Pharmaceutical Cell Biology, Welsh School of PharmacyCardiff UniversityCardiffUK
  3. 3.Faculty of PharmacyTabriz University of Medical SciencesTabrizIran