Chlamydophila pneumoniae enhances secretion of VEGF, TGF-beta and TIMP-1 from human bronchial epithelial cells under Th2 dominant microenvironment.
OBJECTIVE
Chlamydophila pneumoniae infection in the airways is thought to be associated with the pathogenesis of asthma, especially in non-atopic severe asthma with irreversible airway obstruction that may be related to airway remodeling. Here, we investigated whether C. pneumoniae infection enhances the secretion of critical chemical mediators for airway remodeling, such as VEGF, TGF-beta, and TIMP-1, in human bronchial epithelial cells (BECs) in a Th2-dominant microenvironment.


METHODS
Human bronchial epithelial cells (BEAS-2B cells) were infected with C. pneumoniae strain TW183 and cultured in both a Th1-dominant microenvironment with INF-gamma and a Th2-dominant microenvironment with IL-4 or IL-13 added to the culture medium. The VEGF, TGF-beta, and TIMP-1 levels in the culture supernatants were measured using enzyme-linked immunosorbent assays (ELISA). The activation of NF-kappaB in each experimental condition was determined using an electrophoretic mobility shift assay.


RESULTS
Chlamydophila pneumoniae-infected BECs showed enhanced secretion of VEGF, TGF-beta, and TIMP-1 compared with non-infected BECs. The levels of cytokines secreted from BECs were increased more when IL-13 was added to the culture medium. C. pneumoniae-infected BECs also showed increased NF-kappaB activation.


CONCLUSIONS
These results suggest that C. pneumoniae plays a role in the pathogenesis of airway remodeling in asthma, revealing a Th2-dominant immune response. Further studies are required to clarify the precise mechanism of C. pneumoniae infection in airway remodeling.
Department of Allergy, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Chan-Sun
CS
Park
Tae-Bum
TB
Kim
Keun Ae
KA
Moon
Yun-Jeong
YJ
Bae
Hee Ran
HR
Lee
Min Kyoung
MK
Jang
Hee-Bom
HB
Moon
You Sook
YS
Cho
Asthma; Chlamydophila pneumonia; epithelial cells; tissue inhibitor of metalloproteinases; transforming growth factor beta; vascular endothelial growth factor A