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Journal of Biomedicine and Biotechnology
Volume 2010, Article ID 428618, 10 pages
http://dx.doi.org/10.1155/2010/428618
Research Article

Dual Effect of Neutrophils on pIgR/Secretory Component in Human Bronchial Epithelial Cells: Role of TGF- 𝛽

Institute of Experimental and Clinical Research, Pole Pneumology, ENT and Dermatology, Cliniques Universitaires St-Luc, Université Catholique de Louvain (UCL), Brussels B-1200, Belgium

Received 2 December 2009; Revised 17 May 2010; Accepted 24 May 2010

Academic Editor: Susan A. Rotenberg

Copyright © 2010 Céline Ratajczak et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Neutrophils have a dual affect on epithelial pIgR/SC, the critical receptor for transcellular routing of mucosal IgA, but mechanisms of pIgR/SC upregulation remain elusive. Requirements of cytokine, redox, and signalling pathways for pIgR/SC production were assessed in human bronchial epithelial (Calu-3) cells cocultured with increasing numbers of blood neutrophils. Increased SC production was observed after incubation for 48 hrs with intermediate neutrophil numbers (1.25 to 2 . 5 × 1 0 6 ), was favoured by the elastase inhibitor SLPI, and correlated with increased TGF- 𝛽 production. Exogenous TGF- 𝛽 stimulated SC production with a maximal effect at 48 hrs and both TGF- 𝛽 - and neutrophil-driven SC upregulation were dependent on redox balance and p38 MAP-kinase activation. This paper shows that activated neutrophils could upregulate epithelial pIgR/SC production through TGF- 𝛽 -mediated activation of a redox-sensitive and p38 MAPK-dependent pathway. An imbalance between the two neutrophil-driven opposite mechanisms (SC upregulation and SC degradation) could lead to downregulation of pIgR/SC, as observed in severe COPD.