801. Programmed death-1 receptor negatively regulates LPS-mediated IL-12 production and differentiation of murine macrophage RAW264.7 cells.
- Author
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Cho HY, Choi EK, Lee SW, Jung KO, Seo SK, Choi IW, Park SG, Choi I, and Lee SW
- Subjects
- Animals, Antibodies, Blocking, Antigen Presentation drug effects, Antigen Presentation immunology, Antigens, Differentiation biosynthesis, Antigens, Differentiation genetics, B7-1 Antigen metabolism, B7-1 Antigen pharmacology, B7-H1 Antigen, Cell Differentiation drug effects, Cell Differentiation immunology, Cell Line, Down-Regulation, Endocytosis drug effects, Interleukin-12 genetics, Lipopolysaccharides pharmacology, Lymphocyte Culture Test, Mixed, MAP Kinase Kinase 4 metabolism, Macrophages drug effects, Macrophages immunology, Macrophages pathology, Membrane Glycoproteins metabolism, Membrane Glycoproteins pharmacology, Mice, Peptides metabolism, Peptides pharmacology, Programmed Cell Death 1 Receptor, Receptors, Immunologic immunology, Recombinant Fusion Proteins metabolism, Recombinant Fusion Proteins pharmacology, Signal Transduction drug effects, Signal Transduction immunology, Interleukin-12 biosynthesis, Macrophages metabolism, Receptors, Immunologic metabolism
- Abstract
While programmed death-1 (PD-1), a co-inhibitory member of CD28 immunoglobulin superfamily plays negative roles in effector functions of T cells and B cells, little is known about the function of PD-1 expressed on innate immune cells. In this study, we demonstrate that IL-12 production was greatly suppressed in LPS-stimulated RAW264.7 cells upon PD-1 engagement with B7-H1.Fc fusion protein, and was restored in the presence of antagonistic anti-PD-1 mAb. PD-1-mediated suppression of IL-12 production in LPS-stimulated RAW264.7 cells was mediated by inhibition of Janus N-terminal-linked kinase (JNK) signaling pathway, and to a lesser extent, phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway through the recruitment of SHP-2 to PD-1 cytoplasmic tail. B7-H1.Fc-mediated PD-1 engagement also downregulates the expression of co-stimulatory molecules such as CD80, CD86, MHC class I and II proteins in LPS-stimulated RAW264.7 cells. Furthermore, the endocytic activity is enhanced but the allostimulatory capacity is suppressed in LPS-treated RAW264.7 cells upon PD-1 engagement. Taken together, our results reveal a novel function of macrophage PD-1 in the negative regulation of IL-12 synthesis and differentiation into dendritic cell-like cells.
- Published
- 2009
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