Antigen presentation and T cell activation by dendritic cells in radiation damage / 中国辐射卫生

ABSTRACT

@#<b>Objective</b> To explore dendritic cells (DCs)-mediated antigen presentation for radiation-injured cells by using the <i>in vitro</i> cell co-culture technology to simulate the <i>in vivo </i>microenvironment of the lung tissue. <b>Methods</b> ⁶⁰Co γ-irradiated mouse lung epithelial cells (MLE-12) were cultured with bone marrow-derived DCs and/or splenic T lymphocytes for 48 hours. Flow cytometry was used to measure the expression levels of costimulatory molecules (CD80/86) and antigenic peptide recognition complexes (the major histocompatibility complex [MHC] class Ⅰ/Ⅱ) on DCs and T cell activation markers (CD69/28/152) as well as the numbers of CD4⁺ and CD8⁺ T cells. <b>Results</b> ⁶⁰Co γ irradiation significantly increased the apoptosis rate of MLE-12 cells in a dose-dependent manner, and significantly stimulated the expression of CD80/86 and MHC Ⅱ on DCs, without direct activation of T cells. After γ (6 Gy)-irradiated MLE-12 cells were co-cultured with DCs and T lymphocytes for 48 h, there were significant increases in the expression of CD69 and CD28 on T cells, the numbers of CD4⁺ and CD8⁺ T cells, and the expression of CD86 and MHC I on DCs, as compared with the control groups. <b>Conclusion</b> Radiation-injured cells can stimulate antigen presentation by DCs and activate T cells.