Expression of B7-1, B7-2, and interleukin 12 in bleomycin-induced pneumopathy in mice.
BACKGROUND
The bleomycin-induced pneumopathy involves a T cell-mediated immune response. T cell activation requires both antigen/MHC recognition and costimulatory signals. The CD28 receptor on T cells with its ligand B7 represents one of the most important examples of this costimulation. Interleukin 12 (IL-12) has a strong synergistic effect with the B7-1/CD28 interaction on inducing proliferation and cytokine production in T cells.


METHODS
In this study, we investigated the expression of B7-1, B7-2, and IL-12 in bleomycin-induced pneumopathy in mice using reverse transcription polymerase chain reaction (RT-PCR), RT in situ PCR, and immunohistochemistry.


RESULTS
We observed concurrent upregulation of B7-1, B7-2, and IL-12p40 mRNA in the lung tissues at 1 h to 7 days after bleomycin instillation into the trachea. B7-1 mRNA and protein were found in bronchiolar epithelial cells as well as macrophages, B7-2 and IL-12p40 mRNA appeared to be expressed in mononuclear cells.


CONCLUSIONS
These findings indicate that T cell-mediated immune response in this model involves the upregulation of B7-1, B7-2, and IL-12p40 mRNA, and also demonstrate the aberrant expression of B7-1 in bronchiolar epithelial cells.
Research Institute for Diseases of the Chest, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Y
Y
Kaneko
K
K
Kuwano
N
N
Hagimoto
H
H
Miyazaki
M
M
Kawasaki
M
M
Fujita
R
R
Kunitake
T
T
Maeyama
N
N
Hara
D000818:Animals; D000900:Anti-Bacterial Agents / Q000276:immunology* / Q000633:toxicity*; D015703:Antigens, CD / Q000096:biosynthesis / Q000276:immunology*; D018122:B7-1 Antigen / Q000096:biosynthesis / Q000276:immunology*; D051940:B7-2 Antigen; D001761:Bleomycin / Q000276:immunology* / Q000633:toxicity*; D018664:Interleukin-12 / Q000096:biosynthesis / Q000276:immunology*; D008171:Lung Diseases / Q000139:chemically induced / Q000276:immunology* / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000276:immunology*; D051379:Mice
D000900:Anti-Bacterial Agents; D015703:Antigens, CD; D018122:B7-1 Antigen; D051940:B7-2 Antigen; C497965:Cd86 protein, mouse; D008562:Membrane Glycoproteins; D001761:Bleomycin; D018664:Interleukin-12