Inhibition of allergic bronchial asthma by thrombomodulin is mediated by dendritic cells.
BACKGROUND
bronchial asthma is caused by inappropriate acquired immune responses to environmental allergens. It is a major health problem, with a prevalence that is rapidly increasing. Curative therapy is not currently available.


OBJECTIVE
to test the hypothesis that thrombomodulin (TM) inhibits allergic bronchial asthma by inducing tolerogenic dendritic cells (DCs).


METHODS
the protective effect of TM was evaluated using a murine asthma model. Asthma was induced in mice by exposure to chicken egg ovalbumin, and the effects of inhaled TM or TM-treated DCs were assessed by administering before ovalbumin exposure.


RESULTS
treatment with TM protects against bronchial asthma measured as improved lung function and reduced IgE and cells in alveolar lavage fluid by inducing tolerogenic dendritic dells. These are characterized by high expression of surface TM (CD141/TM(+)) and low expression of maturation markers and possess reduced T-cell costimulatory activity. The CD141/TM(+) DCs migrate less toward chemokines, and after TM treatment there are fewer DCs in the draining lymph node and more in the lungs. The TM effect is independent of its role in coagulation. Rather, it is mediated via the TM lectin domain directly interacting with the DCs.


CONCLUSIONS
the results of this study show that TM is a modulator of DC immunostimulatory properties and a novel candidate drug for the prevention of bronchial asthma in atopic patients.
Takagi
Takehiro
T
Department of Immunology, Mie University School of Medicine, Edobashi 2-174, Tsu City, Mie Prefecture 514 8507, Japan.
Taguchi
Osamu
O
Toda
Masaaki
M
Ruiz
Daniel Boveda
DB
Bernabe
Paloma Gil
PG
D'Alessandro-Gabazza
Corina N
CN
Miyake
Yasushi
Y
Kobayashi
Tetsu
T
Aoki
Shinya
S
Chiba
Fumiko
F
Yano
Yutaka
Y
Conway
Edward M
EM
Munesue
Seiichi
S
Yamamoto
Yasuhiko
Y
Yamamoto
Hiroshi
H
Suzuki
Koji
K
Takei
Yoshiyuki
Y
Morser
John
J
Gabazza
Esteban C
EC
D000280:Administration, Inhalation; D000818:Animals; D001249:Asthma / Q000188:drug therapy* / Q000276:immunology / Q000378:metabolism; D003713:Dendritic Cells / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D004195:Disease Models, Animal; D005434:Flow Cytometry; D005500:Follow-Up Studies; D006801:Humans; D007111:Immunity, Cellular / Q000187:drug effects*; D051379:Mice; D011994:Recombinant Proteins; D018180:Thrombomodulin / Q000008:administration & dosage*
D011994:Recombinant Proteins; D018180:Thrombomodulin