Bacillus Calmette-Guérin Suppresses Asthmatic Responses via CD4(+)CD25(+) Regulatory T Cells and Dendritic Cells.
OBJECTIVE
Bacillus Calmette-Guérin (BCG) is known to suppress the asthmatic responses in a murine model of asthma and to induce dendritic cells (DCs) maturation. Mature DCs play a crucial role in the differentiation of regulatory T cells (Tregs), which are known to regulate allergic inflammatory responses. To investigate whether BCG regulates Tregs in a DCs-mediated manner, we analyzed in a murine model of asthma.


METHODS
BALB/c mice were injected intraperitoneally with BCG or intravenously with BCG-stimulated DCs and then sensitized and challenged with ovalbumin (OVA). Mice were analysed for bronchial hyperresponsiveness (BHR), the influx of inflammatory cells in the bronchoalveolar lavage (BAL) fluid, and histopathological changes in the lung. To identify the mechanisms, IgE, IgG1 and IgG2a in the serum were analysed and the CD25+ Tregs in the mice were depleted with anti-CD25 monoclonal antibody (mAb).


RESULTS
BCG and the transfer of BCG-stimulated DCs both suppressed all aspects of the asthmatic responses, namely, BHR, the production of total IgE and OVA-specific IgE and IgGs, and pulmonary eosinophilic inflammation. Anti-CD25mAb treatment reversed these effects.


CONCLUSIONS
BCG can attenuate the allergic inflammation in a mouse model of asthma by a Tregs-related mechanism that is mediated by DCs.
Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul, Korea.
Young-Joon
YJ
Kim
Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul, Korea.
Ha-Jung
HJ
Kim
Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul, Korea.
Mi-Jin
MJ
Kang
Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul, Korea.
Ho-Sung
HS
Yu
Department of Pediatrics, Childhood Asthma Atopy Center, Research Center for Standardization of Allergic Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Ju-Hee
JH
Seo
Department of Pediatrics, Childhood Asthma Atopy Center, Research Center for Standardization of Allergic Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Hyung-Young
HY
Kim
Department of Internal Medicine, Research Center for Pulmonary Disorders, Chonbuk National University Medical School, Jeonju, Korea.
Seoung-Ju
SJ
Park
Department of Internal Medicine, Research Center for Pulmonary Disorders, Chonbuk National University Medical School, Jeonju, Korea.
Yong-Chul
YC
Lee
Department of Pediatrics, Childhood Asthma Atopy Center, Research Center for Standardization of Allergic Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Soo-Jong
SJ
Hong
BCG; T-lymphocytes, regulatory; allergic inflammation; asthma; dendritic cells; mouse