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.
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.
Authors: S Segawa; D Goto; A Iizuka; S Kaneko; M Yokosawa; Y Kondo; I Matsumoto; T Sumida Journal: Clin Exp Immunol Date: 2016-08-02 Impact factor: 4.330