1. Decreased inducible expression of CD80 and CD86 in human monocytes after ultraviolet-B irradiation: its involvement in inactivation of allogenecity.
- Author
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Fujihara M, Takahashi TA, Azuma M, Ogiso C, Maekawa TL, Yagita H, Okumura K, and Sekiguchi S
- Subjects
- Antibodies, Monoclonal immunology, Antibodies, Monoclonal pharmacology, Antigen-Presenting Cells immunology, Antigen-Presenting Cells metabolism, Antigens, CD genetics, Antigens, CD immunology, B7-1 Antigen genetics, B7-1 Antigen immunology, B7-2 Antigen, Base Sequence, Dose-Response Relationship, Radiation, HLA-DR Antigens genetics, HLA-DR Antigens immunology, Humans, Intercellular Adhesion Molecule-1 immunology, Interferon-gamma pharmacology, Leukocytes, Mononuclear immunology, Leukocytes, Mononuclear metabolism, Lymphocyte Activation, Lymphocyte Culture Test, Mixed, Membrane Glycoproteins genetics, Membrane Glycoproteins immunology, Molecular Sequence Data, T-Lymphocyte Subsets immunology, Antigen-Presenting Cells radiation effects, Antigens, CD biosynthesis, B7-1 Antigen biosynthesis, Gene Expression Regulation radiation effects, HLA-DR Antigens biosynthesis, Leukocytes, Mononuclear radiation effects, Lymphocyte Cooperation radiation effects, Membrane Glycoproteins biosynthesis, Ultraviolet Rays
- Abstract
Ultraviolet-B (UV-B) irradiation of antigen presenting cells (APCs) modifies their allogenecity, resulting in inhibition of the proliferative response of T cells in mixed lymphocyte reaction (MLR). Costimulation by the CD28 ligand CD80 (B7/B7-1) and CD86 (B70/B7-2) plays an important role during T-cell proliferation by augmenting synthesis of interleukin-2 (IL-2) and other cytokines. In this study, we demonstrated induced expression of both CD80 and CD86 during allogeneic MLR, though human freshly isolated monocytes express CD86 constitutively with a much lower level of CD80. A monoclonal antibody (MoAb) against CD86, but not CD80, efficiently inhibited allogeneic T-cell proliferative responses stimulated with highly purified monocytes. UV-B exposure (0 to 1,000 J/m2) of monocytes inhibited the proliferation of T lymphocytes in MLR in a dose-dependent manner. Flow cytometric analysis showed that UV-B exposure of monocytes impaired the constitutive expression of CD54 (intercellular adhesion molecule-1) by 24 hours after irradiation, but the effect on CD86 was relatively less. The surface expression of CD80, CD86, CD54, and HLA-DR on monocytes was further augmented by interferon (IFN)-gamma; this cytokine-induced expression was dose-dependently reduced by UV-B irradiation. Similarly, the upregulation of these molecules following allogeneic MLR was downregulated by UV-B irradiation. UV-B irradiation of monocytes inhibited the expression of IL-2 mRNA in monocyte-stimulated allogeneic MLR. In contrast, the addition of anti-CD28 MoAb at the onset of MLR prevented, at least partially, the reduction of IL-2 mRNA. These results strongly suggest that the impairment of inducible expression of CD86 and CD80 may contribute to the reduced MLR response following exposure of monocytes of UV-B.
- Published
- 1996